Processed Meats: Improving Safety, Nutrition and Quality (Woodhead Publishing Series in Food Science, Technology and Nutrition)

Processed meats

© Woodhead Publishing Limited, 2011

Related titles: Improving the sensory and nutritional quality of fresh meat (ISBN 978-1-84569-343-5) Understanding of the scientific basis of quality attributes in meat is becoming more advanced, providing more effective approaches to the control of meat eating and technological quality. This important collection reviews essential knowledge of the mechanisms underlying quality characteristics and methods to improve meat sensory and nutritional quality. An introductory section analyses the scientific basis of meat quality attributes, such as texture, colour and flavour. The following part covers the important area of genetic and genomic influences on meat quality. Final chapters assess production and processing influences on meat quality, such as dietary antioxidants and carcass interventions. Meat products handbook: practical science and technology (ISBN 978-1-84569-050-2) Based on over 20 years’ experience, this is a comprehensive one-volume reference on the main types of meat products and their methods of manufacture. Lawrie’s meat science Seventh edition (ISBN 978-1-84569-159-2) Lawrie’s meat science has established itself as a standard work for both students and professionals in the meat industry. Its basic theme remains the central importance of biochemistry in understanding the production, storage, processing and eating quality of meat. At a time when so much controversy surrounds meat production and nutrition, Lawrie’s meat science provides a clear guide which takes the reader from the growth and development of meat animals, through the conversion of muscle to meat, to the point of consumption. The seventh edition includes details of significant advances in meat science which have taken place in recent years, especially in areas of eating quality of meat and meat biochemistry. Details of these books and a complete list of Woodhead’s titles can be obtained by: • visiting our web site at www.woodheadpublishing.com • contacting Customer Services (e-mail: [email protected]; fax: +44 (0) 1223 832819; tel.: +44 (0) 1223 499140 ext. 130; address: Woodhead Publishing Limited, 80, High Street, Sawston, Cambridge CB22 3HJ, UK) If you would like to receive information on forthcoming titles, please send your address details to: Francis Dodds (address, tel. and fax as above; e-mail: [email protected]). Please confirm which subject areas you are interested in.

© Woodhead Publishing Limited, 2011

Woodhead Publishing Series in Food Science, Technology and Nutrition: Number 211

Processed meats Improving safety, nutrition and quality Edited by J. P. Kerry and J. F. Kerry

Oxford

Cambridge

Philadelphia

New Delhi

© Woodhead Publishing Limited, 2011

Published by Woodhead Publishing Limited, 80 High Street, Sawston, Cambridge CB22 3HJ, UK www.woodheadpublishing.com Woodhead Publishing, 1518 Walnut Street, Suite 1100, Philadelphia, PA 19102-3406, USA Woodhead Publishing India Private Limited, G-2, Vardaan House, 7/28 Ansari Road, Daryaganj, New Delhi – 110002, India www.woodheadpublishingindia.com First published 2011, Woodhead Publishing Limited © Woodhead Publishing Limited, 2011 The authors have asserted their moral rights. This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. Reasonable efforts have been made to publish reliable data and information, but the authors and the publishers cannot assume responsibility for the validity of all materials. Neither the authors nor the publishers, nor anyone else associated with this publication, shall be liable for any loss, damage or liability directly or indirectly caused or alleged to be caused by this book. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming and recording, or by any information storage or retrieval system, without permission in writing from Woodhead Publishing Limited. The consent of Woodhead Publishing Limited does not extend to copying for general distribution, for promotion, for creating new works, or for resale. Specific permission must be obtained in writing from Woodhead Publishing Limited for such copying. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. Library of Congress Control Number: 2011932265 ISBN 978-1-84569-466-1 (print) ISBN 978-0-85709-294-6 (online) ISSN 2042-8049 Woodhead Publishing Series in Food Science, Technology and Nutrition (print) ISSN 2042-8057 Woodhead Publishing Series in Food Science, Technology and Nutrition (online) The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry policy, and which has been manufactured from pulp which is processed using acid-free and elemental chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. Typeset by Toppan Best-set Premedia Limited Printed by TJI Digital, Padstow, Cornwall, UK

© Woodhead Publishing Limited, 2011

Contents

Contributor contact details......................................................................... Woodhead Publishing Series in Food Science, Technology and Nutrition ...............................................................................................

Part I

1

2

Processed meats: market-driven changes, legislative issues and product development............................................................

Consumer demands and regional preferences for meat ............... L. B. Catlett, New Mexico State University, USA 1.1 Introduction ............................................................................ 1.2 The effect of taste on meat consumption ........................... 1.3 The effect of choice on meat consumption ........................ 1.4 Determinates of consumer demand for meat .................... 1.5 Consumption patterns of meat and economic data for selected countries ............................................................. 1.6 Future trends in meat consumption .................................... 1.7 References ............................................................................... Processed meat products: consumer trends and emerging markets ............................................................................... M. D. de Barcellos, Federal University of Rio Grande do Sul (UFRGS), Brazil and K. G. Grunert and J. Scholderer, Aarhus Unversity, Denmark 2.1 Introduction: processed meats and modern life dilemmas ...........................................................................

© Woodhead Publishing Limited, 2011

xv xxi

1 3 3 4 5 5 16 26 29

30

30

vi

Contents 2.2 2.3 2.4 2.5 2.6 2.7 2.8

3

4

5

6

Consumer judgment of meat quality ................................... Ongoing consumer trends ..................................................... New positioning strategies for the meat industry .............. Emerging markets .................................................................. Future trends .......................................................................... Sources of further information and advice ......................... References ...............................................................................

Food safety and processed meats: globalisation and the challenges ...................................................................................... P. Wall and J. Kennedy, University College Dublin, Ireland 3.1 Introduction ............................................................................ 3.2 Trade liberalisation ................................................................ 3.3 Safety of processed meat from a nutritional point of view ........................................................................... 3.4 Conclusions ............................................................................. 3.5 References ............................................................................... Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli: significance and contamination in processed meats.............. C. C. Adley and C. Dillon, University of Limerick, Ireland 4.1 Introduction ............................................................................ 4.2 Listeria monocytogenes.......................................................... 4.3 Escherichia coli ....................................................................... 4.4 Salmonella ............................................................................... 4.5 Conclusions ............................................................................. 4.6 References ............................................................................... 4.7 Appendix: glossary .................................................................

31 34 37 45 47 49 49

54 54 55 68 69 70

72 72 73 78 85 92 93 107

The use of irradiation in processed meat products ....................... E. J. Lee, Iowa State University, USA and D. U. Ahn, Iowa State University, USA and Seoul National University, Korea 5.1 Introduction ............................................................................ 5.2 Control of pathogens in processed meat products ............ 5.3 Effects of irradiation on meat quality ................................. 5.4 Prevention of quality changes in irradiated processed meat ....................................................................... 5.5 Future trends .......................................................................... 5.6 Acknowledgement ................................................................. 5.7 References and further reading ...........................................

109

Regulation of processed meat labels in the European Union ..... M. Fogden, Agriculture and Horticulture Development Board, UK 6.1 Introduction ............................................................................

134

© Woodhead Publishing Limited, 2011

109 111 114 121 123 124 124

134

Contents 6.2 6.3 6.4 6.5 6.6 6.7 6.8 7

The European Union (EU) general food law regulation ......................................................................... Labelling and claims rules..................................................... Other measures ...................................................................... Codex Alimentarius (‘food code’) ....................................... Provision of food information to consumers...................... Sources of further information and advice ......................... References ...............................................................................

Use of sensory science as a practical commercial tool in the development of consumer-led processed meat products .............. M. G. O’Sullivan and J. P. Kerry, University College Cork, Ireland and D. V. Byrne University of Copenhagen, Denmark 7.1 Introduction ............................................................................ 7.2 Past and present status of sensory-based quality control in processed meats.................................................... 7.3 State of the art: an overview of specific sensory science methodologies and approaches used for processed meat product development ................................. 7.4 Future trends: a holistic implementation of sensory science at key stages of meat product development ......... 7.5 Conclusions: success in processed meat product production development – sensory science-based development of successful consumer processed meat products ......................................................................... 7.6 Case studies ............................................................................. 7.7 Acknowledgements ................................................................ 7.8 References and further reading ...........................................

Part II Ingredients: past and future roles in processed meat manufacture ....................................................................... 8

Scientific modeling of blended meat products ............................... R. A. LaBudde, Least Cost Formulations Ltd, USA and T. C. Lanier, North Carolina State University, USA 8.1 Introduction ............................................................................ 8.2 The least-cost formulation (LCF) model ............................ 8.3 Linear science-based models for meat product properties .................................................................. 8.4 Solving the least-cost formulation–science-based formulation (LCF-SBM) problem ....................................... 8.5 Advanced topics ..................................................................... 8.6 Conclusions ............................................................................. 8.7 References ...............................................................................

© Woodhead Publishing Limited, 2011

vii

136 137 147 151 152 153 154

156

156 157

162 166

172 173 175 177

183 185

185 190 196 208 212 215 215

viii 9

10

11

12

Contents Blood by-products as ingredients in processed meat .................... D. Parés, E. Saguer and C. Carretero, University of Girona, Spain 9.1 Introduction: blood characterisation, recovery and processing ........................................................................ 9.2 Applications of blood in processed meat products ........... 9.3 Future trends .......................................................................... 9.4 Sources of further information and advice ......................... 9.5 References ............................................................................... Utilisation of hydrocolloids in processed meat systems ............... R. McArdle and R. Hamill, Teagasc Food Research Centre, Ireland and J. P. Kerry, University College Cork, Ireland 10.1 Introduction ............................................................................ 10.2 The meat matrix ..................................................................... 10.3 Challenges faced by the meat industry today .................... 10.4 Regulation and scrutiny concerning hydrocolloid usage in processed meats ...................................................... 10.5 Application of hydrocolloids in processed meats .............. 10.6 Future trends and conclusions.............................................. 10.7 References ............................................................................... Use of cold-set binders in meat systems ......................................... J. A. Boles, Montana State University, USA 11.1 Introduction ............................................................................ 11.2 Meat source ............................................................................. 11.3 Traditional restructured meat products............................... 11.4 Cold-set binders...................................................................... 11.5 Particle size reduction ........................................................... 11.6 Binder comparisons ............................................................... 11.7 Advantages of restructuring ................................................. 11.8 Advantages of cold set binders ............................................ 11.9 Restructured meat products quality control ...................... 11.10 References and further reading ........................................... Using natural and novel antimicrobials to improve the safety and shelf-life stability of processed meat products ............................... A. Lauková, Slovak Academy of Sciences, Slovakia 12.1 Introduction ............................................................................ 12.2 Range of natural antimicrobials for food application ....... 12.3 Combined effect of natural antimicrobials and/or other barriers .......................................................................... 12.4 Food grade sanitisers: natural adjuncts as indirect sanitisers .................................................................... 12.5 Advantages of natural antimicrobials and new perspectives for their application ......................................... 12.6 References ...............................................................................

© Woodhead Publishing Limited, 2011

218

218 223 232 233 234 243

243 245 247 248 249 262 264 270 270 272 274 276 285 288 289 290 291 295 299 299 301 313 315 316 320

Contents 13

14

15

16

ix

Reducing salt in processed meat products...................................... J. M. Barat, Universidad Politécnica de Valencia, Spain and F. Toldrá, Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Spain 13.1 Introduction ............................................................................ 13.2 Influences of salt on processed meats ................................. 13.3 Development of processed meats with low salt content .............................................................................. 13.4 Sources of further information and advice ......................... 13.5 References ...............................................................................

331

Reducing fats in processed meat products ..................................... S. Barbut, University of Guelph, Canada 14.1 Introduction: importance of reducing fat in processed meat products ......................................................................... 14.2 Role of fat in processed meat products .............................. 14.3 Consequences of reducing fat in processed meats from an organoleptic and functional perspective .............. 14.4 Technological methods to reduce fat................................... 14.5 Saturated fat replacement using healthier fats .................. 14.6 Alternative fat-replacing ingredients................................... 14.7 Future trends .......................................................................... 14.8 Sources of further information and advice ......................... 14.9 References ...............................................................................

346

The use of nutraceuticals in processed meat products and their effects on product quality, safety and acceptability ............. J. Hayes and N. Brunton, Teagasc Food Research Centre, Ireland 15.1 Introduction ............................................................................ 15.2 Nutraceuticals and processed meats .................................... 15.3 Product quality ....................................................................... 15.4 Microbial safety ...................................................................... 15.5 Acceptability ........................................................................... 15.6 Future trends .......................................................................... 15.7 References ............................................................................... Use of probiotics and prebiotics in meat products ........................ K. Arihara and M. Ohata, Kitasato University, Japan 16.1 Introduction ............................................................................ 16.2 Probiotics ................................................................................. 16.3 Probiotics and meat fermentation ....................................... 16.4 Prebiotics ................................................................................. 16.5 Meat protein-derived prebiotic peptides ............................ 16.6 Prebiotics and meat products ............................................... 16.7 Future trends ..........................................................................

© Woodhead Publishing Limited, 2011

331 332 335 340 340

346 347 349 350 351 355 365 366 366

372 372 374 377 384 390 392 393 403 403 404 405 408 409 410 411

x

Contents 16.8 16.9

Part III

17

18

19

Sources of further information and advice ......................... References ...............................................................................

413 413

Processing technologies: past and future roles in processed meat manufacture ...................................................

419

Marinating and enhancement of the nutritional content of processed meat products ................................................................... S. M. Yusop, University College Cork, Ireland and National University of Malaysia, Malaysia and M. G. O’Sullivan and J. P. Kerry, University College Cork, Ireland 17.1 Introduction ............................................................................ 17.2 Background and terminology associated with marinating ....................................................................... 17.3 Marinade action: absorption and retention in a marinating system ............................................................... 17.4 Functional ingredients of marinating .................................. 17.5 Methods of marinade delivery ............................................. 17.6 Established effects of marinating ......................................... 17.7 The significance of sensory evaluation in determining quality of marinated products .............................................. 17.8 Future research in marinating technology .......................... 17.9 References and further reading ........................................... Improving the quality of restructured and convenience meat products...................................................................................... M. M. Farouk, AgResearch Limited, New Zealand 18.1 Introduction ............................................................................ 18.2 Restructured whole-tissue and convenience meat products ......................................................................... 18.3 Quality issues of restructured whole-tissue and convenience meat products................................................... 18.4 Improving product quality .................................................... 18.5 Future trends .......................................................................... 18.6 Sources of further information and advice ......................... 18.7 References and further reading ........................................... Heat and processing generated contaminants in processed meats .................................................................................. P. Šimko, Food Research Institute, Slovak Republic and Brno University of Technology, Czech Republic 19.1 Polycyclic aromatic hydrocarbons (PAHs) ......................... 19.2 Biogenic amines (BAs) .......................................................... 19.3 N-nitroso amines (NAs) ........................................................ 19.4 Heterocyclic amines (HAs) ..................................................

© Woodhead Publishing Limited, 2011

421

421 423 427 429 435 438 441 442 443

450 450 451 453 463 470 472 472

478

478 483 488 495

Contents 19.5 19.6 19.7 20

21

22

23

Conclusions ............................................................................. Acknowledgement ................................................................. References and further reading ...........................................

Improving the sensory quality of cured and fermented meat products...................................................................................... F. Toldrá, Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Spain 20.1 Introduction ............................................................................ 20.2 Biochemical basis for flavour development........................ 20.3 Basis for colour and texture development in cured meats ............................................................................. 20.4 Processing factors affecting sensory quality of cured meats ............................................................................. 20.5 Trends to accelerate the processes and/or improve the sensory quality of cured meat products ....................... 20.6 Sources of further information and advice ......................... 20.7 References and further reading ........................................... Improving the sensory and nutritional quality of smoked meat products...................................................................................... E. P. Emmerson, Red Arrow Products, USA 21.1 The process of smoking muscle food products .................. 21.2 Advantages of using natural smoke condensates compared with traditional smoking technologies .............. 21.3 Application methods of liquid smoke condensates to muscle-based food products ............................................. 21.4 Conclusions and future trends.............................................. 21.5 References and further reading ........................................... Online quality assessment of processed meats............................... M. O’Farrell, SINTEF, Norway 22.1 Introduction ............................................................................ 22.2 Meat composition and attributes ......................................... 22.3 Visual inspection of products ............................................... 22.4 Food safety .............................................................................. 22.5 Automation and integration of the quality measurements ......................................................................... 22.6 Sources of further information and advice ......................... 22.7 References ............................................................................... Impact of refrigeration on processed meat safety and quality .... S. J. James and C. James, Food Refrigeration and Process Engineering Research Centre (FRPERC), UK 23.1 Introduction ............................................................................

© Woodhead Publishing Limited, 2011

xi 499 500 500

508

508 509 515 516 517 519 520

527 527 528 533 544 545 546 546 547 552 558 562 563 563 567

567

xii

Contents 23.2 23.3 23.4 23.5

24

25

26

Current understanding of the impact of refrigeration on processed meat safety and quality ................................. Advances in technology and practice to improve processed meat safety and quality ....................................... Future trends .......................................................................... References ...............................................................................

Recent advances in the application of high pressure technology to processed meat products .......................................... Y. Ikeuchi, Kyushu University, Japan 24.1 Introduction ............................................................................ 24.2 Effect of high pressure on the quality of meat and meat products ......................................................................... 24.3 Pressure-processed meat products ....................................... 24.4 Microbial control in meat and meat products using high pressure ........................................................................... 24.5 New applications of high pressure technology in the meat industry .......................................................................... 24.6 Future trends in high pressure processing .......................... 24.7 References ............................................................................... Effects of novel thermal processing technologies on the sensory quality of meat and meat products .................................... J. F. Kerry, Echo Ovens Ltd, Ireland 25.1 Introduction ............................................................................ 25.2 Meat quality ............................................................................ 25.3 Thermal processing ................................................................ 25.4 Thermal processing methods ................................................ 25.5 Consumer preference ............................................................ 25.6 Future trends .......................................................................... 25.7 Sources of further information and advice ......................... 25.8 References ............................................................................... Packaging of cooked meats and muscle-based, convenience-style processed foods ................................................... M. Cruz-Romero and J. P. Kerry, University College Cork, Ireland 26.1 Introduction ............................................................................ 26.2 Cooked meat products .......................................................... 26.3 Definition of packaging and its functions ........................... 26.4 Influence of key trends on consumer behaviour ............... 26.5 Consumer trends in food packaging .................................... 26.6 Choosing packaging materials for cooked meat products .........................................................................

© Woodhead Publishing Limited, 2011

570 582 585 587

590 590 592 596 603 606 606 609

617 617 620 623 628 651 653 655 657

666

666 669 672 675 677 679

Contents

xiii

26.7

Packaging materials and forms used on cooked meats and muscle-based, convenience-style food products ......... 26.8 Developments and recent advances in the use of packaging materials for cooked meats and muscle-based, convenience-style food products................. 26.9 Future trends .......................................................................... 26.10 References ...............................................................................

686 701 701

Index .............................................................................................................

706

© Woodhead Publishing Limited, 2011

681

Contributor contact details

(* = main contact) Editors

Chapter 1

Dr Joseph P. Kerry Food Packaging Group School of Food and Nutritional Sciences University College Cork Cork Ireland

Professor Lowell B. Catlett College of Agricultural, Consumer and Environmental Sciences New Mexico State University Las Cruces, NM USA E-mail: [email protected]

E-mail: [email protected] Chapter 2 Dr John F. Kerry Echo Ovens Ltd Unit 4, Limerick Food Centre Raheen Business Park Raheen Ireland E-mail: [email protected]

Professor M. D. de Barcellos* Management School (EA), PostGraduate Programme in Business Administration (PPGA) Federal University of Rio Grande do Sul (UFRGS) Rua Washington Luis 855/409 Porto Alegre, RS, 90010-460 Brazil E-mail: [email protected] [email protected]

© Woodhead Publishing Limited, 2011

xvi

Contributor contact details

Professor K. G. Grunert and Professor J. Scholderer MAPP – Centre for Research on Customer Relations in the Food Sector Aarhus Unversity Haslegaardsvej 10, DK-8210 Aarhus V Denmark

Chapter 5 Eun Joo Lee Animal Science Department Iowa State University Ames, IA 50011 USA E-mail: [email protected] Dong U. Ahn* Animal Science Department Iowa State University Ames, IA 50011 USA

E-mail: [email protected] [email protected]

Chapter 3 Professor Patrick Wall* and Dr Jean Kennedy College of Life Sciences School of Public Health, Physiotherapy and Population Science Woodview House University College Dublin Belfield Dublin 4 Ireland

E-mail: [email protected]

E-mail: [email protected] [email protected].

Chapter 6

Chapter 4 Catherine Adley* and Colm Dillon Microbiology Laboratory Department of Chemical and Environmental Sciences University of Limerick Limerick Ireland

and Department of Agricultural Biotechnology Major in Biomodulation Seoul National University Seoul 151-921 South Korea

Michael Fogden Agriculture and Horticulture Development Board Stoneleigh Park Kenilworth, CV8 2TL UK E-mail: [email protected]. uk

E-mail: [email protected]

© Woodhead Publishing Limited, 2011

Contributor contact details Chapter 7

Chapter 9

Maurice G. O’Sullivan* and Joseph P. Kerry Food Packaging Group School of Food and Nutritional Sciences University College Cork Cork Ireland

Dr D. Parés*, Dr E. Saguer and Professor C. Carretero Agrifood Technology Institute (INTEA) University of Girona Escola Politècnica Superior Av. Lluís Santaló s/n 17071 Girona Spain

E-mail: [email protected] [email protected] Derek V. Byrne Department of Food Science Sensory Science University of Copenhagen Faculty of Life Sciences Rolighedsvej 30 1958, Frederiksberg C Denmark

xvii

E-mail: [email protected] Chapter 10 R. McArdle* and R. Hamill Teagasc Food Research Centre Ashtown Dublin 15 Ireland E-mail: [email protected]

Chapter 8 Robert A. LaBudde* Least Cost Formulations Ltd 824 Timberlake Drive Virginia Beach, VA 23464-3239 USA E-mail: [email protected]

Dr Joseph P. Kerry Food Packaging Group School of Food and Nutritional Sciences University College Cork Cork Ireland E-mail: [email protected]

Tyre C. Lanier Department of Food Science North Carolina State University Schaub Hall Dan Allen Drive PO Box 7624 Raleigh, NC 27695-7624 USA

Chapter 11 Professor Jane Ann Boles Montana State University Department of Animal and Range Sciences PO Box 172900 Bozeman, MT 59717 USA E-mail: [email protected]

© Woodhead Publishing Limited, 2011

xviii

Contributor contact details

Chapter 12

Chapter 15

Andrea Lauková Institute of Animal Physiology Laboratory of Animal Microbiology Slovak Academy of Sciences Šoltésovej 4-6, SK-04001 Kosˇice Slovakia

Jenny Hayes and Nigel Brunton* Teagasc Food Research Centre Ashtown Dublin 15 Ireland E-mail: [email protected]

E-mail: [email protected] Chapter 16 Chapter 13 José M. Barat Departamento de Tecnología de Alimentos Universidad Politécnica de Valencia Camino de Vera s/n. 46022 Valencia Spain Fidel Toldrá* Instituto de Agroquímica y Tecnología de Alimentos (CSIC) Avenida Agustín Escardino 7 46980 Paterna Valencia Spain E-mail: [email protected]

Keizo Arihara* and Motoko Ohata School of Veterinary Medicine Kitasato University Towada-Shi Aomori 034-8628 Japan E-mail: [email protected]. ac.jp

Chapter 17 Salma M. Yusop Food Packaging Group School of Food and Nutritional Sciences University College Cork Cork Ireland E-mail: [email protected]

Chapter 14

and

Shai Barbut Food Science Department University of Guelph Canada N1G 2W1 E-mail: [email protected]

Food Science Program School of Chemical Sciences and Food Technology National University of Malaysia (UKM) Malaysia

© Woodhead Publishing Limited, 2011

Contributor contact details Maurice G. O’Sullivan and Dr Joseph P. Kerry* Food Packaging Group School of Food and Nutritional Sciences University College Cork Ireland E-mail: [email protected] [email protected]

Chapter 18

xix

Chapter 20 Fidel Toldrá Instituto de Agroquímica y Tecnología de Alimentos (CSIC) Avenida Agustín Escardino 7 46980 Paterna Valencia Spain E-mail: [email protected]

Chapter 21

Dr M. M. Farouk AgResearch Limited Ruakura Research Centre East Street Private Bag 3123 Hamilton 3240 New Zealand E-mail: Mustafa.farouk@ agresearch.co.nz

Edmond P. Emmerson Red Arrow Products 4502 Expo Drive Manitowoc, WI 54220 USA E-mail: e.emmerson@redarrowusa. com

Chapter 22 Chapter 19 Professor Peter Šimko Food Research Institute Priemyselna 4, PO Box 25 82475 Bratislava Slovak Republic E-mail: [email protected]

Dr Marion O’Farrell SINTEF ICT PO Box 124 Blindern NO–0314 Oslo Norway E-mail: [email protected]

and Institute of Food Science and Biotechnology Faculty of Chemistry Brno University of Technology Purkynˇova 118 61200 Brno Czech Republic

© Woodhead Publishing Limited, 2011

xx

Contributor contact details

Chapter 23

Chapter 25

Dr Stephen J. James* and Dr Christian James Food Refrigeration and Process Engineering Research Centre (FRPERC) The Grimsby Institute HSI Building Origin Way Europarc Grimsby, DN37 9TZ UK

Dr John F. Kerry Echo Ovens Ltd Unit 4, Limerick Food Centre Raheen Business Park Raheen Ireland

E-mail: [email protected] [email protected]

Chapter 24 Dr Yoshihide Ikeuchi Muscle and Meat Sciences Department of Bioscience and Biotechnology Graduate School of Agriculture Kyushu University 6-10-1 Hakozaki, Higashi-ku Fukuoka, 812-8581 Japan

E-mail: [email protected]

Chapter 26 Dr Malco Cruz-Romero* and Dr Joseph P. Kerry Food Packaging Group School of Food and Nutritional Sciences University College Cork Cork Ireland E-mail: [email protected] [email protected]

E-mail: [email protected]. ac.jp

© Woodhead Publishing Limited, 2011

Woodhead Publishing Series in Food Science, Technology and Nutrition

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Chilled foods: a comprehensive guide Edited by C. Dennis and M. Stringer Yoghurt: science and technology A. Y. Tamime and R. K. Robinson Food processing technology: principles and practice P. J. Fellows Bender’s dictionary of nutrition and food technology Sixth edition D. A. Bender Determination of veterinary residues in food Edited by N. T. Crosby Food contaminants: sources and surveillance Edited by C. Creaser and R. Purchase Nitrates and nitrites in food and water Edited by M. J. Hill Pesticide chemistry and bioscience: the food–environment challenge Edited by G. T. Brooks and T. Roberts Pesticides: developments, impacts and controls Edited by G. A. Best and A. D. Ruthven Dietary fibre: chemical and biological aspects Edited by D. A. T. Southgate, K. W. Waldron, I. T. Johnson and G. R. Fenwick Vitamins and minerals in health and nutrition M. Tolonen Technology of biscuits, crackers and cookies Second edition D. Manley Instrumentation and sensors for the food industry Edited by E. Kress-Rogers Food and cancer prevention: chemical and biological aspects Edited by K. W. Waldron, I. T. Johnson and G. R. Fenwick Food colloids: proteins, lipids and polysaccharides Edited by E. Dickinson and B. Bergenstahl Food emulsions and foams Edited by E. Dickinson Maillard reactions in chemistry, food and health Edited by T. P. Labuza, V. Monnier, J. Baynes and J. O’Brien The Maillard reaction in foods and medicine Edited by J. O’Brien, H. E. Nursten, M. J. Crabbe and J. M. Ames

© Woodhead Publishing Limited, 2011

xxii 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Woodhead Publishing Series in Food Science, Technology & Nutrition Encapsulation and controlled release Edited by D. R. Karsa and R. A. Stephenson Flavours and fragrances Edited by A. D. Swift Feta and related cheeses Edited by A. Y. Tamime and R. K. Robinson Biochemistry of milk products Edited by A. T. Andrews and J. R. Varley Physical properties of foods and food processing systems M. J. Lewis Food irradiation: a reference guide V. M. Wilkinson and G. Gould Kent’s technology of cereals: an introduction for students of food science and agriculture Fourth edition N. L. Kent and A. D. Evers Biosensors for food analysis Edited by A. O. Scott Separation processes in the food and biotechnology industries: principles and applications Edited by A. S. Grandison and M. J. Lewis Handbook of indices of food quality and authenticity R. S. Singhal, P. K. Kulkarni and D. V. Rege Principles and practices for the safe processing of foods D. A. Shapton and N. F. Shapton Biscuit, cookie and cracker manufacturing manuals Volume 1: ingredients D. Manley Biscuit, cookie and cracker manufacturing manuals Volume 2: biscuit doughs D. Manley Biscuit, cookie and cracker manufacturing manuals Volume 3: biscuit dough piece forming D. Manley Biscuit, cookie and cracker manufacturing manuals Volume 4: baking and cooling of biscuits D. Manley Biscuit, cookie and cracker manufacturing manuals Volume 5: secondary processing in biscuit manufacturing D. Manley Biscuit, cookie and cracker manufacturing manuals Volume 6: biscuit packaging and storage D. Manley Practical dehydration Second edition M. Greensmith Lawrie’s meat science Sixth edition R. A. Lawrie Yoghurt: science and technology Second edition A. Y. Tamime and R. K. Robinson New ingredients in food processing: biochemistry and agriculture G. Linden and D. Lorient Benders’ dictionary of nutrition and food technology Seventh edition D. A. Bender and A. E. Bender Technology of biscuits, crackers and cookies Third edition D. Manley Food processing technology: principles and practice Second edition P. J. Fellows Managing frozen foods Edited by C. J. Kennedy Handbook of hydrocolloids Edited by G. O. Phillips and P. A. Williams Food labelling Edited by J. R. Blanchfield Cereal biotechnology Edited by P. C. Morris and J. H. Bryce Food intolerance and the food industry Edited by T. Dean The stability and shelf-life of food Edited by D. Kilcast and P. Subramaniam Functional foods: concept to product Edited by G. R. Gibson and C. M. Williams Chilled foods: a comprehensive guide Second edition Edited by M. Stringer and C. Dennis

© Woodhead Publishing Limited, 2011

Woodhead Publishing Series in Food Science, Technology & Nutrition 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86

xxiii

HACCP in the meat industry Edited by M. Brown Biscuit, cracker and cookie recipes for the food industry D. Manley Cereals processing technology Edited by G. Owens Baking problems solved S. P. Cauvain and L. S. Young Thermal technologies in food processing Edited by P. Richardson Frying: improving quality Edited by J. B. Rossell Food chemical safety Volume 1: contaminants Edited by D. Watson Making the most of HACCP: learning from others’ experience Edited by T. Mayes and S. Mortimore Food process modelling Edited by L. M. M. Tijskens, M. L. A. T. M. Hertog and B. M. Nicolaï EU food law: a practical guide Edited by K. Goodburn Extrusion cooking: technologies and applications Edited by R. Guy Auditing in the food industry: from safety and quality to environmental and other audits Edited by M. Dillon and C. Griffith Handbook of herbs and spices Volume 1 Edited by K. V. Peter Food product development: maximising success M. Earle, R. Earle and A. Anderson Instrumentation and sensors for the food industry Second edition Edited by E. Kress-Rogers and C. J. B. Brimelow Food chemical safety Volume 2: additives Edited by D. Watson Fruit and vegetable biotechnology Edited by V. Valpuesta Foodborne pathogens: hazards, risk analysis and control Edited by C. de W. Blackburn and P. J. McClure Meat refrigeration S. J. James and C. James Lockhart and Wiseman’s crop husbandry Eighth edition H. J. S. Finch, A. M. Samuel and G. P. F. Lane Safety and quality issues in fish processing Edited by H. A. Bremner Minimal processing technologies in the food industries Edited by T. Ohlsson and N. Bengtsson Fruit and vegetable processing: improving quality Edited by W. Jongen The nutrition handbook for food processors Edited by C. J. K. Henry and C. Chapman Colour in food: improving quality Edited by D. MacDougall Meat processing: improving quality Edited by J. P. Kerry, J. F. Kerry and D. A. Ledward Microbiological risk assessment in food processing Edited by M. Brown and M. Stringer Performance functional foods Edited by D. Watson Functional dairy products Volume 1 Edited by T. Mattila-Sandholm and M. Saarela Taints and off-flavours in foods Edited by B. Baigrie Yeasts in food Edited by T. Boekhout and V. Robert Phytochemical functional foods Edited by I. T. Johnson and G. Williamson Novel food packaging techniques Edited by R. Ahvenainen Detecting pathogens in food Edited by T. A. McMeekin Natural antimicrobials for the minimal processing of foods Edited by S. Roller Texture in food Volume 1: semi-solid foods Edited by B. M. McKenna

© Woodhead Publishing Limited, 2011

xxiv 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109

110 111 112 113 114 115 116 117 118 119 120 121 122 123

Woodhead Publishing Series in Food Science, Technology & Nutrition Dairy processing: improving quality Edited by G. Smit Hygiene in food processing: principles and practice Edited by H. L. M. Lelieveld, M. A. Mostert, B. White and J. Holah Rapid and on-line instrumentation for food quality assurance Edited by I. Tothill Sausage manufacture: principles and practice E. Essien Environmentally-friendly food processing Edited by B. Mattsson and U. Sonesson Bread making: improving quality Edited by S. P. Cauvain Food preservation techniques Edited by P. Zeuthen and L. Bøgh-Sørensen Food authenticity and traceability Edited by M. Lees Analytical methods for food additives R. Wood, L. Foster, A. Damant and P. Key Handbook of herbs and spices Volume 2 Edited by K. V. Peter Texture in food Volume 2: solid foods Edited by D. Kilcast Proteins in food processing Edited by R. Yada Detecting foreign bodies in food Edited by M. Edwards Understanding and measuring the shelf-life of food Edited by R. Steele Poultry meat processing and quality Edited by G. Mead Functional foods, ageing and degenerative disease Edited by C. Remacle and B. Reusens Mycotoxins in food: detection and control Edited by N. Magan and M. Olsen Improving the thermal processing of foods Edited by P. Richardson Pesticide, veterinary and other residues in food Edited by D. Watson Starch in food: structure, functions and applications Edited by A-C. Eliasson Functional foods, cardiovascular disease and diabetes Edited by A. Arnoldi Brewing: science and practice D. E. Briggs, P. A. Brookes, R. Stevens and C. A. Boulton Using cereal science and technology for the benefit of consumers: proceedings of the 12th International ICC Cereal and Bread Congress, 24–26th May, 2004, Harrogate, UK Edited by S. P. Cauvain, L. S. Young and S. Salmon Improving the safety of fresh meat Edited by J. Sofos Understanding pathogen behaviour in food: virulence, stress response and resistance Edited by M. Griffiths The microwave processing of foods Edited by H. Schubert and M. Regier Food safety control in the poultry industry Edited by G. Mead Improving the safety of fresh fruit and vegetables Edited by W. Jongen Food, diet and obesity Edited by D. Mela Handbook of hygiene control in the food industry Edited by H. L. M. Lelieveld, M. A. Mostert and J. Holah Detecting allergens in food Edited by S. Koppelman and S. Hefle Improving the fat content of foods Edited by C. Williams and J. Buttriss Improving traceability in food processing and distribution Edited by I. Smith and A. Furness Flavour in food Edited by A. Voilley and P. Etievant The Chorleywood bread process S. P. Cauvain and L. S. Young Food spoilage microorganisms Edited by C. de W. Blackburn Emerging foodborne pathogens Edited by Y. Motarjemi and M. Adams

© Woodhead Publishing Limited, 2011

Woodhead Publishing Series in Food Science, Technology & Nutrition 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156

xxv

Benders’ dictionary of nutrition and food technology Eighth edition D. A. Bender Optimising sweet taste in foods Edited by W. J. Spillane Brewing: new technologies Edited by C. Bamforth Handbook of herbs and spices Volume 3 Edited by K. V. Peter Lawrie’s meat science Seventh edition R. A. Lawrie in collaboration with D. A. Ledward Modifying lipids for use in food Edited by F. Gunstone Meat products handbook: practical science and technology G. Feiner Food consumption and disease risk: consumer-pathogen interactions Edited by M. Potter Acrylamide and other hazardous compounds in heat-treated foods Edited by K. Skog and J. Alexander Managing allergens in food Edited by C. Mills, H. Wichers and K. Hoffman-Sommergruber Microbiological analysis of red meat, poultry and eggs Edited by G. Mead Maximising the value of marine by-products Edited by F. Shahidi Chemical migration and food contact materials Edited by K. Barnes, R. Sinclair and D. Watson Understanding consumers of food products Edited by L. Frewer and H. van Trijp Reducing salt in foods: practical strategies Edited by D. Kilcast and F. Angus Modelling microorganisms in food Edited by S. Brul, S. Van Gerwen and M. Zwietering Tamime and Robinson’s Yoghurt: science and technology Third edition A. Y. Tamime and R. K. Robinson Handbook of waste management and co-product recovery in food processing Volume 1 Edited by K. W. Waldron Improving the flavour of cheese Edited by B. Weimer Novel food ingredients for weight control Edited by C. J. K. Henry Consumer-led food product development Edited by H. MacFie Functional dairy products Volume 2 Edited by M. Saarela Modifying flavour in food Edited by A. J. Taylor and J. Hort Cheese problems solved Edited by P. L. H. McSweeney Handbook of organic food safety and quality Edited by J. Cooper, C. Leifert and U. Niggli Understanding and controlling the microstructure of complex foods Edited by D. J. McClements Novel enzyme technology for food applications Edited by R. Rastall Food preservation by pulsed electric fields: from research to application Edited by H. L. M. Lelieveld and S. W. H. de Haan Technology of functional cereal products Edited by B. R. Hamaker Case studies in food product development Edited by M. Earle and R. Earle Delivery and controlled release of bioactives in foods and nutraceuticals Edited by N. Garti Fruit and vegetable flavour: recent advances and future prospects Edited by B. Brückner and S. G. Wyllie Food fortification and supplementation: technological, safety and regulatory aspects Edited by P. Berry Ottaway

© Woodhead Publishing Limited, 2011

xxvi 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187

Woodhead Publishing Series in Food Science, Technology & Nutrition Improving the health-promoting properties of fruit and vegetable products Edited by F. A. Tomás-Barberán and M. I. Gil Improving seafood products for the consumer Edited by T. Børresen In-pack processed foods: improving quality Edited by P. Richardson Handbook of water and energy management in food processing Edited by J. Klemesˇ, R. Smith and J-K Kim Environmentally compatible food packaging Edited by E. Chiellini Improving farmed fish quality and safety Edited by Ø. Lie Carbohydrate-active enzymes Edited by K-H. Park Chilled foods: a comprehensive guide Third edition Edited by M. Brown Food for the ageing population Edited by M. M. Raats, C. P. G. M. de Groot and W. A. Van Staveren Improving the sensory and nutritional quality of fresh meat Edited by J. P. Kerry and D. A. Ledward Shellfish safety and quality Edited by S. E. Shumway and G. E. Rodrick Functional and speciality beverage technology Edited by P. Paquin Functional foods: principles and technology M. Guo Endocrine-disrupting chemicals in food Edited by I. Shaw Meals in science and practice: interdisciplinary research and business applications Edited by H. L. Meiselman Food constituents and oral health: current status and future prospects Edited by M. Wilson Handbook of hydrocolloids Second edition Edited by G. O. Phillips and P. A. Williams Food processing technology: principles and practice Third edition P. J. Fellows Science and technology of enrobed and filled chocolate, confectionery and bakery products Edited by G. Talbot Foodborne pathogens: hazards, risk analysis and control Second edition Edited by C. de W. Blackburn and P. J. McClure Designing functional foods: measuring and controlling food structure breakdown and absorption Edited by D. J. McClements and E. A. Decker New technologies in aquaculture: improving production efficiency, quality and environmental management Edited by G. Burnell and G. Allan More baking problems solved S. P. Cauvain and L. S. Young Soft drink and fruit juice problems solved P. Ashurst and R. Hargitt Biofilms in the food and beverage industries Edited by P. M. Fratamico, B. A. Annous and N. W. Gunther Dairy-derived ingredients: food and neutraceutical uses Edited by M. Corredig Handbook of waste management and co-product recovery in food processing Volume 2 Edited by K. W. Waldron Innovations in food labelling Edited by J. Albert Delivering performance in food supply chains Edited by C. Mena and G. Stevens Chemical deterioration and physical instability of food and beverages Edited by L. H. Skibsted, J. Risbo and M. L. Andersen Managing wine quality Volume 1: viticulture and wine quality Edited by A. G. Reynolds

© Woodhead Publishing Limited, 2011

Woodhead Publishing Series in Food Science, Technology & Nutrition 188

xxvii

Improving the safety and quality of milk Volume 1: milk production and processing Edited by M. Griffiths 189 Improving the safety and quality of milk Volume 2: improving quality in milk products Edited by M. Griffiths 190 Cereal grains: assessing and managing quality Edited by C. Wrigley and I. Batey 191 Sensory analysis for food and beverage quality control: a practical guide Edited by D. Kilcast 192 Managing wine quality Volume 2: oenology and wine quality Edited by A. G. Reynolds 193 Winemaking problems solved Edited by C. E. Butzke 194 Environmental assessment and management in the food industry Edited by U. Sonesson, J. Berlin and F. Ziegler 195 Consumer-driven innovation in food and personal care products Edited by S. R. Jaeger and H. MacFie 196 Tracing pathogens in the food chain Edited by S. Brul, P. M. Fratamico and T. A. McMeekin 197 Case studies in novel food processing technologies: innovations in processing, packaging, and predictive modelling Edited by C. J. Doona, K. Kustin and F. E. Feeherry 198 Freeze-drying of pharmaceutical and food products T-C. Hua, B-L. Liu and H. Zhang 199 Oxidation in foods and beverages and antioxidant applications Volume 1: understanding mechanisms of oxidation and antioxidant activity Edited by E. A. Decker, R. J. Elias and D. J. McClements 200 Oxidation in foods and beverages and antioxidant applications Volume 2: management in different industry sectors Edited by E. A. Decker, R. J. Elias and D. J. McClements 201 Protective cultures, antimicrobial metabolites and bacteriophages for food and beverage biopreservation Edited by C. Lacroix 202 Separation, extraction and concentration processes in the food, beverage and nutraceutical industries Edited by S. S. H. Rizvi 203 Determining mycotoxins and mycotoxigenic fungi in food and feed Edited by S. De Saeger 204 Developing children’s food products Edited by D. Kilcast and F. Angus 205 Functional foods: concept to product Second edition Edited by M. Saarela 206 Postharvest biology and technology of tropical and subtropical fruits Volume 1 Edited by E. M. Yahia 207 Postharvest biology and technology of tropical and subtropical fruits Volume 2 Edited by E. M. Yahia 208 Postharvest biology and technology of tropical and subtropical fruits Volume 3 Edited by E. M. Yahia 209 Postharvest biology and technology of tropical and subtropical fruits Volume 4 Edited by E. M. Yahia 210 Food and beverage stability and shelf life Edited by D. Kilcast and P. Subramaniam 211 Processed meats: improving safety, nutrition and quality Edited by J. P. Kerry and J. F. Kerry

© Woodhead Publishing Limited, 2011

xxviii 212 213 214 215 216 217 218 219 220 221 222 223

Woodhead Publishing Series in Food Science, Technology & Nutrition

Food chain integrity: a holistic approach to food traceability, safety, quality and authenticity Edited by J. Hoorfar, K. Jordan, F. Butler and R. Prugger Improving the safety and quality of eggs and egg products Volume 1 Edited by F. Van Immerseel, Y. Nys and M. Bain Improving the safety and quality of eggs and egg products Volume 2 Edited by Y. Nys, M. Bain and F. Van Immerseel Feed and fodder contamination: effects on livestock and food safety Edited by J. Fink-Gremmels Hygiene in the design, construction and renovation of food processing factories Edited by J. Holah and H. L. M. Lelieveld Technology of biscuits, crackers and cookies Fourth edition Edited by D. Manley Nanotechnology in the food, beverage and nutraceutical industries Edited by Q. Huang Rice quality: A guide to rice properties and analysis K. R. Bhattacharya Meat, poultry and seafood packaging Edited by J. P. Kerry Reducing saturated fats in foods Edited by G. Talbot Handbook of food proteins Edited by G. O. Phillips and P. A. Williams Lifetime nutritional influences on cognition, behaviour and psychiatric illness Edited by D. Benton

© Woodhead Publishing Limited, 2011

1 Consumer demands and regional preferences for meat L. B. Catlett, New Mexico State University, USA

Abstract: Consumer preference for meat is examined via the determinates of demand. Price, income, cross and supply elasticity are discussed, explained and compared among various countries. Regional preferences for meat are explored and a comparison is given of developing and developed countries. General economic and demographic rules are listed as a way to forecast future meat consumption patterns. Key words: price elasticity of demand, income elasticity, cross elasticity, supply elasticity, l-glutamate, Engel curve.

1.1 Introduction Humans, being omnivores, have constantly altered their diets throughout history. We know that societies that emerged close to lands suitable only for roaming animals had diets richer in meat than more sedate farming communities that were located in arable land areas. Families that settled either in the western United States or in central Australia over 100 years ago had diets dominated by mutton, lamb and beef compared with farming families in Ireland that consumed most of their calories via potatoes. Climate certainly has played a role in food consumption patterns but culture and technology likewise have had major influences. Spanish colonizers that settled in the southwest United States brought numerous species of farm animals with them in the 1500s but as they settled in the river valleys they gradually adopted the culture of the Native Americans that farmed maize, legumes and chile peppers via irrigation. Climate, culture and technology helped form individual as well as group diets throughout much of the last 6000 years of recorded history. The generation born during the early 1900s that grew to maturity during the Great Depression and World War II did not live in a radically different way from the generation born in the early 1700s. Their

© Woodhead Publishing Limited, 2011

4

Processed meats

food consumption patterns were dominated by where they lived (climate), how they were raised (culture) and technology. During the 200 years from 1700 to 1900 climate and culture changed little and the only food technologies to have any impact on consumption patterns – canning and freezing – emerged late in the 1800s. Thus you could predict with a large degree of certainty that if you grew up in urban New York City in either the early 1700s or early 1900s your meat and food consumption patterns were not materially different. Likewise, farmers in rural France in the early 1700s did not differ very much from their counterparts in the early 1900s in their meat consumption patterns which were set by the climate and culture. Yet as economies have matured and science slowly emerged, two other forces altered how and what consumers want in their food during the last 100 years. The concepts of taste and choice have emerged to be major factors in consumer demand for food. As consumers began to express their individual taste differences, naturally more choices in processed meats have emerged. Pearson and Gillett (1999) reported 41 categories of fresh and frozen beef and pork not counting sausages which added another 24 choices just in the United States. This did not account for other types of meat (marine, poultry and other red meats) nor for other types of processing such as canning. To be sure the list has grown dramatically by adding categories such as aging, grass fed, free range and organic. Furthermore new cuts and flavorings make the list of choices for processed meats almost limitless.

1.2 The effect of taste on meat consumption A couple of events happened almost simultaneously in opposite parts of the world in the early 1900s that altered meat consumption forever. Lehrer (2007) describes how Augusta Escoffier changed professional food preparation by developing meat stock as an addition to all foods, not just meat dishes. He carefully described his process of using meat bones and parts to make a stock and then deglaze the seared meat to extract the caramelized amino acids in his 1903 book Guide Culinaire. He changed not only French food but professional food preparation worldwide. Prior to Escoffier’s work, science said that the tongue can detect only four flavors – sweet, salty, bitter and sour. Escoffier knew that his stock or sauce added a flavor that humans could and did detect and it was none of the four flavors. Little did he know that he had stumbled upon the amino acid l-glutamate. Half way across the world from France, a Japanese chemist Kikunae Ikeda discovered the molecule glutamic acid in 1907. With cooking or fermentation glutamic acid forms l-glutamate – the fifth flavor (otherwise referred to as umami or savoriness) that the tongue can taste. Ikeda stabilized glutamic acid with salt and formed the famous monosodium glutamate (MSG). MSG became a chef’s secret way to add a new taste sensation without having to cook Escoffier’s stock for 12 hours. The rest, as they say, is history. In 2000 a

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

5

tongue receptor was discovered that senses only glutamate and l-amino acids. Technology and science now gave consumers a way to understand and appreciate why they generally love the taste of meat and how that taste sensation can be added to other foods via l-glutamate.

1.3 The effect of choice on meat consumption History has always recorded that the very wealthy can and do eat whatever they want and generally that has always included numerous forms of meat. Economic democracy is really a product of the twentieth century whereby the emergence of a middle class allowed humans to have a choice about what foods they wanted to consume. Certainly the salad years of the Roman Empire and Greece as well as isolated city-states at various times in history produced similar results for their citizens, but nothing rivals the emergence of the middle classes in the 1900s in changing food consumption patterns that were long dominated by climate and culture. After World War II more and more consumers changed their food consumption habits as they moved into middle class. Consumers could now use taste as a choice beyond the bounds of what culture and climate dictated as their food. The middle classes now had enough income to choose beyond the base necessities of life, ushering in the most significant change in demand in human history.

1.4 Determinates of consumer demand for meat 1.4.1 Relationship between price and quantity demanded The theory of consumer demand says that consumers have a diminishing utility, thus to induce more consumption, price has to be lowered. Therefore an inverse relationship between the quantity demanded and price exists. An individual consumer will pay a certain price for a beef steak. The beef steak satisfies their need/want (utility). To induce that same consumer to purchase more beef steak, the price would have to be lowered since the consumer was satisfied with the first beef steak. This ‘law of diminishing utility’ has a few exceptions but has survived the test of time. As consumers respond to changes in price for meat, they will likewise change the quantity they demand (consume). Figure 1.1 illustrates this effect – if the price of meat increases from price A to price B, consumers will decrease the quantity of meat they demand from quantity A to quantity B. In mature economies, most of the yearly changes in meat consumption will come from changes in price. Given an existing customer base, market experts know to ‘move more product’ price has to be lowered. How responsive quantity changes are to price changes (price elasticity of demand) is measured by the ratio of the percent change in quantity versus the percent change in price and is represented by the formula:

© Woodhead Publishing Limited, 2011

Processed meats

Price

6

B   A  Demand for meat

B

A

Quantity

Fig. 1.1 Change in quantity demanded for meat. Source: USDA (2009).

E=

percent change in quantity Q2 − Q1 = (Q1 + Q2 ) 2 percent change in price

P2 − P1

( P1 + P2 ) 2

Where E = price elasticity of demand, P = price and Q = quantity. If price changes 1% and quantity demanded changes by more than 1%, the product is said to be elastic and if the quantity demanded changes by less than 1% it is inelastic. The degree of elasticity of a product is roughly determined by the amount and availability of substitutes for the product. Items that have many substitutes tend to have an elastic demand because if the price changes, consumers can readily substitute other items. Products that have few, if any, substitutes have inelastic demand curves, whereas if a major price change occurs, consumers cannot adjust their consumption very much because of the lack of choices (real or imagined). Catlett and Libbin (2007, p. 37) point out that price elasticity of demand is fickle: ‘What is a substitute to one consumer is not to another. To a consumer who is rich or simply brand loyal, a certain type of luxury car may have few if any substitutes and therefore have a fairly inelastic demand curve that otherwise would be elastic for another group of consumers.’ Table 1.1 illustrates for selected countries price elasticity of demand calculations for various food groupings. The figure is divided into two groups of countries: five emerging countries and five highly developed countries. It is interesting to note that in all ten of the countries meat is considered an inelastic good. In Albania, for example, a 1% increase in the price of meat would cause the quantity demanded to go down approximately six-tenths of 1% (0.593). In the United States a 1% increase in the price of meat would induce less than one-tenth of 1% (0.089). Meat is a product that consumers feel there are few, if any, substitutes. In fact, in the ERS (USDA, 2009) study from which the data for Table 1.1 were selected, 114 countries were listed and all have inelastic demand coefficients for meat. Table 1.1 reveals another interesting observation: all of the price elasticity of demand coefficients are lower in the highly developed

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat Table 1.1

7

Price elasticity of demand for various foods in selected countries Fish

Dairy

Fats/oils

Breads/ cereals

Beverages/ tobacco

Other foods

−0.665 −0.706 −0.729 −0.654 −0.788

−0.641 −0.676 −0.687 −0.633 −0.733

−0.374 −0.418 −0.445 −0.340 −0.482

−0.348 −0.399 −0.433 −0.304 −0.471

−0.769 −0.857 −1.011 −0.735 −1.309

−0.591 −0.618 −0.618 −0.588 −0.651

Highly developed countries Ireland −0.373 −0.414 Japan −0.252 −0.279 United States −0.089 −0.098 Canada −0.245 −0.271 France −0.286 −0.314

−0.401 −0.270 −0.095 −0.262 −0.305

−0.219 −0.145 −0.047 −0.140 −0.152

−0.198 −0.129 −0.040 −0.125 −0.129

−0.468 −0.314 −0.108 −0.304 −0.348

−0.372 −0.251 −0.088 −0.244 −0.285

Country

Meat

Emerging countries Albania −0.593 Azerbaijan −0.620 Cote d’ Ivoire −0.620 Indonesia −0.590 Kenya −0.654

Source: USDA (2009).

Table 1.2 Total food expenditures as a percentage of total (2009) Country

Total food expenditures (%)

Albania Azerbaijan Côte d’Ivoire Indonesia Kenya Ireland Japan United States Canada France

69.24 73.50 44.31 50.62 45.82 16.58 14.87 9.72 11.68 15.34

Source: USDA (2009).

countries than in the emerging economies. Why? Perhaps if another set of data is added, a clearer reason emerges. Look at the data in Table 1.2 which shows how much each consumer spends in each country out of their household budget. In the emerging economies food expenditure as a percent of overall expenditures is high, thus even though food as a group has an inelastic demand curve, withinfood groups are relatively less inelastic than in the highly developed economies. If you spend 60% of your income on food and the price of meat goes up, you quickly substitute another food. On the other hand if you spend 10% of your income on food and the price of meat increases, you are reluctant to substitute.

© Woodhead Publishing Limited, 2011

8

Processed meats

Price

Changes in demand To create a whole new demand structure necessitates changes in at least one of four factors: (1) consumer incomes, (2) tastes and preferences, (3) price of substitutes and complements and (4) the number of consumers in the marketplace. It is important to understand the difference between a change in quantity demanded and changes in demand. Figure 1.2 demonstrates a change in demand whereby for a given price (A), more is demanded from quantity A to quantity B. This change in demand could be from an increase in the number of consumers in the market, from increased incomes, from consumers changing their tastes and preferences or from changes in the price of substitutes and/or complements. Mature economies do not see major changes in demand except as their populations grow or some major change, such as occurred in Europe, Canada and the United States when mad cow disease (bovine spongiform encephalopathy, BSE) occurred in the beef supply, and consumers (primarily in other countries) reduced their demand of beef produced in those countries as consumers changed their tastes and preferences via fear of the beef produced in countries that had BSE. Figure 1.3 shows the drop-off in beef exports in 2004 from the United

A D2   D1 A

B

Quantity

Fig. 1.2 Change in demand for meat. Metric tons

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Fig. 1.3 Beef exports (tonnes) from the United States. Source: United States Meat Export Federation (2009).

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

9

Metric tons

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Fig. 1.4 Pork exports from the United States. Source: United States Meat Export Federation (2009).

Metric tons

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Fig. 1.5 Lamb exports from the United States. Source: United States Meat Export Federation (2009).

States when BSE was discovered in late 2003. Exports of pork and lamb did not drop-off in 2004 as illustrated in Figs 1.4 and 1.5. However, rapidly growing economies such as China and Ireland have seen major changes in meat consumption as their incomes have grown (increased the demand) for meat. In 1994 China’s per capita GDP (gross domestic product) was $300 but by 2003 it had grown to $1100 (an almost four-fold increase) (CIA, 2009). During the same period per capita meat consumption increased from 36 to 54 Kg. (Fig. 1.6). Likewise, Ireland’s GDP in 1994 was $15,834 and increased by 2003 to $29,800 (almost doubling) (CIA, 2009). Ireland’s per capita meat consumption went from 83 kg in 1994 to 104 kg in 2003 (Fig. 1.6). Let’s look at the four major drivers of changes in demand and how they impact meat consumption. Consumer incomes The measure of how changes in income affect demand is measured by income elasticity as defined by:

© Woodhead Publishing Limited, 2011

10

Processed meats Ireland

China

104

83

Meat consumption (kg/capita)

Meat consumption (kg/capita)

54  36

1994

2003

1994

2003

Fig. 1.6 Meat consumption in China and Ireland. Source: UN FAO (2009).

percent change in quantity demanded of product A percent change in income Q2 a − Q1a Y2 − Y1 = (Q2a + Q1a ) 2 (Y1 + Y2 ) 2

IE =

where IE = income elasticity, Q = quantity and I = income. If a 1% change in income induces a positive (negative) change in the quantity demanded of a product, the product is called a normal good (inferior). If a 1% change in income causes a more than 1% change in quantity demanded of the product, the product is known as a luxury good. Numerous studies have shown that different cuts of meat, types of meat and forms of processing will have different income elasticity measures. Sausages in the United Kingdom are considered inferior goods as is ground beef in the United States, while prime rib type beef cuts often approach luxury status in both the United Kingdom and the United States. The term ‘Engel curve’ is often used to express the relationship between income and food expenditures. In general the income elasticity for food is less than 1 because as consumer incomes increase, the proportion spent on food declines, even though total expenditures may increase. Since food is a necessity of life, as incomes increase consumers will spend their new wealth on items other than food. Table 1.3 shows this relationship holds true for both the emerging economy of Bangladesh as well as the mature economy of Hong Kong. While consumers in Bangladesh will spend more of their income increase on food than in Hong Kong (0.733 versus 0.254 – almost three times more), consumers in both countries will spend even more on recreation (1.916 versus 1.285). The data reinforce the concept of income elasticity that says that the percent change is important, but just as important is the level of initial income of the consumers. Consumers that have relatively low incomes will generally consume more of all products, even food, while higher income individuals, having been sated, will not consume more relative to lower income individuals. Table 1.4 further illustrates this

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Source: USDA (2009).

0.733 0.254

Food, beverages, and tobacco

0.922 0.904

Clothing and footwear 1.252 1.157

Gross rent, fuel, and power 1.247 1.155

House operations 1.565 1.068

Medical care

Income elasticity for Bangladesh and Hong Kong for various products

Bangladesh Hong Kong

Country

Table 1.3

1.082 1.068

Education

1.273 1.165

Transportation and communications

1.916 1.285

Recreation

1.533 1.233

Other

12

Processed meats

Table 1.4 groups

Income elasticity for Bangladesh and Hong Kong for various food

Country

Meat

Fish

Dairy

Fats/oils

Breads, cereals

Beverages, tobacco

Other foods

Bangladesh Hong Kong

0.784 0.270

0.903 0.299

0.859 0.289

0.543 0.154

0.523 0.137

1.139 0.335

0.781 0.269

Source: USDA (2009).

between the two economies of Bangladesh and Hong Kong for food products relative to meat, comparing income elasticity. In Bangladesh beverages and tobacco are luxury goods, as a 1% increase in income would generate a 1.139% increase in consumption, yet in Hong Kong, a 1% increase in income would cause consumers there to increase their consumption of beverages and tobacco only 0.335%. All food products in Bangladesh are more income elastic than Hong Kong, especially meat. A 1% increase in income in Bangladesh would induce almost three times the increase in meat consumption as in Hong Kong (0.784 versus 0.270).

1.4.2 Tastes and preferences How consumers view various aspects of food will determine the overall importance of certain categories in consumption patterns. Mature economies during the last 20 years have changed their consumption of foods when healthcare studies point to health issues for certain products – fat levels, fat types or ‘good’ compounds. As certain economies find their population aging as in most of Europe, North America and Japan consumers change their wants and needs. Likewise, Ireland has the opposite situation whereby they have the youngest overall population in Europe. Major drivers of tastes and preferences include health, age, gender and culture. Age, gender and culture tend to influence the demand for food, but are generally stable and change slowly over time, while health can be a trigger point to rapidly shift demand as consumers react positively and negatively to health news stories. Often health issues do not have to directly relate to human health to change the demand for meat, as the 2001 issue of foot and mouth disease in the United Kingdom proved so clearly. In early 2001 foot and mouth disease was discovered in pigs in the United Kingdom and by February 2001 the European Union had banned the importation of livestock and meat products from the country. Before the problem was solved, over 10 million head of livestock had been destroyed at an estimated cost of $16 billion, not to mention the loss to consumers in other countries because of the ban. Demand can be shut off by policy: even though foot and mouth disease is rarely harmful to humans, humans can spread the

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

13

disease via their clothing and shoes to animals and thus increase the problem of stopping the disease. 1.4.3 Price of substitutes and complements When products have similar characteristics they are said to be substitutes and when the consumption of one is related to the consumption of the other they are called complements. In some cases beef and pork are substitutes; (although not in those cultures where pork is taboo because of religion). Chicken is likewise a substitute for some other meats such as beef or pork, but might not be a substitute for buffalo. The consumption of lamb in North American and Europe is closely tied in some cultures to the consumption of mint jelly and the two would be complements. The classic ‘meat and potatoes’ are complements in many cultures just as bacon and eggs are in the United States for breakfast and eggs and black pudding in Ireland. There is a similar preference for bacon in Ireland. However, in the United States the bacon is streaky (belly) bacon and in Ireland/United Kingdom the bacon supplied is a loin cut (rindless or rind on). Measuring the relationship of substitutes and complements is called cross price elasticity of demand and is measured by: XE = =

percent change in quantity demanded of product A percent change in price of product B Q2a − Q1a (Q2a + Q1a ) 2

P2 b − P1b ( P1b + P2 b ) 2

where XE = cross price elasticity of demand, Q = quantity of product A and P = price of product B. If the relationship is positive, then the products are said to be substitutes, that is, an increase in the price of one product would cause an increase in the quantity demanded of another product. Mbala (1987) found that the cross price elasticity of demand between goat meat and beef was 0.95 in Cameroon, thus they were almost perfect substitutes. Bielik and Sajbidorova (2009) found that the cross price elasticity between pork and poultry to be 0.62 and between pork and beef to be 0.34 in the Czech Republic and thus substitutes, but not anywhere close to perfect substitutes. A negative relationship implies the goods are complements and in the broad category of meat the literature is shallow concerning studies looking at meat complements. However, Riley (2009) reported that a recent BBC news article pointed out that sales of baked beans are up in the United Kingdom as are the sales of white bread as the two are complements for beans on toast. 1.4.4 Population changes As population increases or decreases, the demand for meat does likewise. The number of consumers in the marketplace determines the overall level

© Woodhead Publishing Limited, 2011

14

Processed meats

Table 1.5

Population dynamics of France and Canada

County

Population 2008

Population growth (yearly)

Net immigration

Natural growth

France Canada

64,057,792 33,212,696

367,692 275,665

94,805 186,655

272,887 89,010

74.00% 32.00%

Source: CIA (2009).

of demand and if the population is growing by a certain percent the demand curve for meat will grow, and vice versa. It is important to break population growth into natural and migratory. If populations are increasing by natural positive birth rates in excess of deaths, consumers will likely be more similar to their ancestors than if the growth rate is due to immigration. Countries such as Canada, the United States and Australia have large numbers of highly diverse immigrants whereas China’s population growth is primarily composed of natural growth with relatively little immigration. Estimations of changes in the demand for meat have to consider the make-up of the population growth. Consider the data in Table 1.5 comparing Canada and France. France is almost twice the size of Canada in population yet Canada has almost twice the number of immigrants. France’s natural growth rate is 74% while Canada’s is only 32%. France can expect fairly stable consumption patterns for meat. Canada’s population growth is dominated by immigrants (68%) who will mimic the consumption habits of their home country, not that of Canada. Canada’s growth in meat consumption will be dynamic, France’s less so.

1.4.5 Determinates of the supply of meat Half of the price equation involves supply and thus it is important to consumption, but it is also important to look at the underpinnings of supply to help understand how it impacts consumption of meat. As with demand, changes in the quantity supplied is a function of price. Price elasticity of supply is calculated similar to demand, as: ES =

percent change in quantity Q2 − Q1 = percent change in price (Q1 + Q2 ) 2

P2 − P1 ( P1 + P2 ) 2

where ES = price elasticity of supply, Q = quantity and P = price. If a 1% change in the price of meat occurs and a more (less) than 1% in quantity supplied occurs, the product is said to be elastic (inelastic). The major determinate of how responsive quantity supplied is relative to price changes is the degree of fixation of the resources used in production and the biological constraints of animals. For example, if the price of beef rose

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

15

dramatically in the United States or Canada, it would be very difficult for producers to supply an equal percentage increase quickly given the way beef is produced in both countries. Both countries have large expanses of grasslands whose primary use is for beef production and then the animals are put in intensive feed yards and fed a concentrated grain and protein ration. The whole process takes over two years from conception to slaughter to complete, and is thus fairly inelastic in response to major price changes. Of course, certain beef products could respond quicker to price changes, such as ground meat which can be composed of many different muscle groups within the animal unlike loins. Likewise, consumers may want an aged product or special type such as Kobe which necessitates a longer production process and is thus inelastic. Changes in supply result in whole shifts in the supply curve and are caused by changes in the cost of production and/or the number of producers in the market. If a new regulation was imposed on producers that increased the cost of production, the supply curve would shift to the left and if demand remained the same, would result in a higher price for the product, and vice versa. Changes in the number of producers will shift the supply curve; however, those changes generally occur slowly within a country due to the cost of entering into a production process. Most meat production operations require substantial capital investments and thus the number of producers is fairly stable in most countries. However, in the global marketplace the number of producers can change overnight depending upon trade policies. For example, when Canada faced its first case of BSE and other countries embargoed beef from Canada, beef producers in Canada faced a major challenge. Canadian beef producers supply not only beef for Canada but export approximately one-third (0.5 million tons) of their annual production (approximately 1.5–1.7 million tons) to the world. The BSE embargo was put in place by many countries in 2004 but effectively started in 2003 as shown in Table 1.6. The fact that the beef producers could not alter the production system in the short run caused a major decline in the price of beef and thus consumers in Canada increased the quantity demanded of the product and absorbed an additional 200,000 tons of beef.

Table 1.6

Canadian beef exports

Year

Tons

1999 2000 2001 2002 2003

425,967 445,916 489,726 521,457 324,765

Source: International Markets Bureau (2009).

© Woodhead Publishing Limited, 2011

16

Processed meats

1.4.6 Putting it all together Trying to determine not only why consumers eat meat and what influences their decisions to consume more or less is an extremely complicated process and one that is difficult to describe with precision. Certainly the framework of supply and demand and the factors that determine changes in supply and demand and how price is an allocator is an important first step to helping companies and governments understand what factors are important to consider in determining meat consumption. However, forecasting changing diet patterns for rapidly growing economies is difficult. Will they mimic similar economies or take a different path? Heilig (1999) points out the problem with China: ‘One can imagine that China’s average diet will approach the current pattern of Hong Kong, Singapore, or South Korea. However, there are deep ethnic and cultural differences between countries that must also be taken into account.’ The beginning point is to assemble current trends and look at the major drivers of change.

1.5 Consumption patterns of meat and economic data for selected countries The following tables show meat consumption data and selected demographic data for four broad groups: (1) The Americas which includes Canada, the United States, Mexico and Brazil, (2) Europe which includes the United Kingdom, Ireland, France, Germany, Spain and Russia, (3) Asia which includes China , Japan and South Korea, and (4) Australia and New Zealand. A brief discussion about how to view and potentially use the data from each figure is presented for each of the four selected areas. Most countries are represented in the data sets listed in the reference section. The data for China is a combination of demographic data from China and income elasticity and price elasticity data from Singapore as no complete data is available for mainland China. 1.5.1 The Americas Comparing the data between the four countries in the Americas group (Tables 1.7–1.10) yields some similarities and major differences. All four countries saw increases from 1994 to 2003 in overall consumption of meat. In the rapidly growing economies of Mexico and Brazil the growth in per capita meat consumption was a dramatic 29% for Mexico and 20% for Brazil. By contrast the mature economies of Canada and the United States had meat consumption growth for the period of 1994 to 2003 of only 4%. Poultry was the major driver in the increases in all four countries. Surprisingly consumers in Canada and the United States respond to price changes in meat and income in markedly different ways. In both countries meat is highly priced, and income inelastic, but more so in the United States than Canada. Canadians would buy 2.75 times more meat for

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

17

Table 1.7 Meat consumption data and selected demographic data for Canada Meat consumption kg/capita/year1 Year

Bovine

1994 2003

33 34

Mutton 0 1

Poultry 30 36

Fish Fish Pork (fresh water) (ocean) 2 3

24 25

29 27

Meat 94 98

Total food expenditures 11.68% of total expenditures2 (2003) Meat food expenditures 16.47% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.2842 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.2182 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.376 −0.304

0.155 −0.125

Dairy

Fats/oils

0.324 −0.262

0.174 −0.140

Fish

Fruits/ Meat Other veg

0.335 0.240 0.302 0.301 −0.271 −0.194 −0.245 −0.244

Population 33,212,6963 (2009) Population growth rate 0.833 (2009) Net migration rate 5.62 migrants/1000 population3 (2008) Sources:

1

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

Table 1.8 Meat consumption data and selected demographic data for the United States Meat Consumption kg/capita/year1 Year

Bovine

1994 2003

43 41

Mutton Poultry 0 0

43 50

Fish Fish (fresh water) (ocean) 2 3

21 21

Pork

Meat

30 30

118 123

Total food expenditures 9.73% of total expenditures2 (2003) Meat food expenditures 19.58% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.1032 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.0822 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.134 −0.108

0.050 −0.040

Dairy

Fats/oils

0.177 −0.095

0.059 −0.047

Fish

0.121 0.086 0.110 0.109 −0.098 −0.070 −0.089 −0.088

Population 303,824,6403 (2009) Population growth rate 0.8833 (2009) Net migration rate 2.92 migrants/1000 population3 (2008) Sources:

1

Fruits/ Meat Other veg

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

© Woodhead Publishing Limited, 2011

18

Processed meats

Table 1.9

Meat consumption data and selected demographic data for Brazil

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

30 33

Mutton Poultry 0 0

18 33

Fish Fish Pork (fresh water) (ocean) 1 2

5 6

16 13

Meat 67 81

Total food expenditures 22.71% of total expenditures2 (2003) Meat food expenditures 24.54% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.6222 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.3912 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.877 −0.709

0.404 −0.327

Dairy

Fats/oils

0.718 −0.581

0.429 −0.347

Fish

Fruits/ veg

Meat

Other

0.747 0.533 0.633 0.661 −0.604 −0.431 −0.536 −0.534

Population 196,342,5923 (2009) Population growth rate 1.2283 (2009) Net migration rate −0.09 migrants/1000 population3 (2008) Sources:

1

UN FAO (2009),2 USDA (2009), 3 CIA (2009).

Table 1.10

Meat consumption data and selected demographic data for Mexico

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

16 17

Mutton Poultry 1 1

15 25

Fish Fish (fresh water) (ocean) 1 1

11 11

Pork

Meat

11 12

45 58

Total food expenditures 26.63% of total expenditures2 (2003) Meat food expenditures 17.33% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.5922 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.3852 (2003) Food subgroups2 (2009) Beverages/ Breads/ Dairy tobacco cereals IE ED

0.807 −0.653

0.360 0.679 −0.291 −0.549

Fats/oils 0.704 −0.315

Fish

1

Meat

Other

0.389 0.504 0.630 0.628 −0.570 −0.408 −0.510 −0.508

Population 109,955,4003 (2009) Population growth rate 1.1423 (2009) Net migration rate −3.84 migrants/1000 population3 (2008) Sources:

Fruits/ veg

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

19

a given increase in income than United States citizens would (0.302/0.11 = 2.75). Even though Canadians would respond to an increase in income with their purchase of meat at a rate of almost three times a similar income increase in the United States, since the United States is 9.15 times larger in population than Canada, the overall increase in meat consumption would be 3.32 times larger in the United States (9.15/2.75 = 3.32). Likewise, for a given change in the price of meat, Canadians would respond positively or negatively 2.75 times the rate of United States citizens (−0.245/−0.089 = 2.75). Brazil and Mexico have similar income elasticity (0.633 and 0.630) and price elasticity of demand (−0.536 and −0.510) for meat. A given change in the price of meat or income in either country would produce similar results. Brazil is roughly twice the size of Mexico so any price or income change would produce approximately twice the overall effect in Brazil versus Mexico. Both Brazil and Mexico have positive natural growth rates and negative migration so they do not have to deal with a rapidly changing immigrant population and their effect on changing diets. The opposite is true for Canada and the United States. They both have small natural growth rates and major immigrant growth with Canada’s immigrant growth rate almost twice that of the United States (5.62/2.92 = 1.92). Forecasting future meat diets for Mexico and Brazil would tend to be easier than for Canada or the United States, other things being equal. 1.5.2 Europe Although Russia’s size would allow it to be equally part of either Europe or Asia, for discussion purposes it is included in the European grouping. Tables 1.11–1.16 show data for the United Kingdom, France, Ireland, Germany, Spain and Russia. Meat consumption increased slightly in the United Kingdom (12%) and France (4%) while Ireland jumped 23% and Spain 22%. Ireland had a major increase in pork consumption and Spain had major increases in both pork and poultry. Per capita GDP growth in Ireland from 1994 to 2003 doubled and in Spain it increased 36% (FAO, 2009). Income elasticity for meat in both Spain and Ireland is almost identical (0.47 and 0.461 respectively) and thus the rapidly growing economies of both countries pushed up meat consumption. Minor decreases in meat consumption occurred in Germany (1%) and Russia (5%) over the period 1994 to 2003. Germany had slow economic growth from 1994 to 2003 of slightly less than 2% per year and data for Russia is unreliable but most estimates point to a slight decline in GDP from 1994 to 2003. Therefore meat consumption would be expected to be reduced. The United Kingdom, France and Spain had slow natural population growth rates with Germany and Russia posting negative growth rates. Ireland was almost alone in Europe in having a high natural growth rate and additionally, one of the highest rates of migrant population growth in the world. Well-established developed nations such as the United Kingdom, France and Germany have similar income elasticity for meat (0.351, 0.353 and 0.328

© Woodhead Publishing Limited, 2011

20

Processed meats

Table 1.11 Meat consumption data and selected demographic data for the United Kingdom Meat consumption kg/capita/year1 Year

Bovine

1994 2003

16 20

Mutton Poultry 0 5

Fish Fish (fresh water) (ocean)

25 29

20 23

2 3

Pork

Meat

25 25

25 83

Total food expenditures 16.37% of total expenditures2 (2003) Meat food expenditures 12.57% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.3302 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.2492 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.432 −0.349

0.169 −0.137

Dairy

Fats/oils

0.375 −0.304

0.194 −0.157

Fish

Fruits/ Meat Other veg

0.387 0.277 0.351 0.35 −0.313 −0.224 −0.284 −0.283

Population 60,943,9123 (2009) Population growth rate 0.2763 (2009) Net migration rate 2.17 migrants/1000 population3 (2008) Sources:

1

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

Table 1.12

Meat consumption data and selected demographic data for France

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

25 26

Mutton Poultry 4 3

Fish Fish Pork (fresh water) (ocean)

23 24

2 3

29 31

35 38

Meat 94 98

Total food expenditures 15.34% of total expenditures2 (2003) Meat food expenditures 24.92% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.3222 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.2512 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.431 −0.348

0.159 −0.129

Dairy

Fats/oils

0.377 −0.305

0.187 −0.152

Fish

1

UN FAO (2009),

2

USDA (2009),

3

Meat

Other

0.389 0.278 0.353 0.352 −0.314 −0.225 −0.286 −0.285

Population 64,057,7923 (2009) Population growth rate 0.5743 (2009) Net migration rate 1.48 migrants/1000 population3 (2008) Sources:

Fruits/ veg

CIA (2009).

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat Table 1.13

21

Meat consumption data and selected demographic data for Ireland

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

18 23

Mutton Poultry 7 5

26 28

Fish Fish (fresh water) (ocean) 2 2

18 17

Pork

Meat

31 44

83 102

Total food expenditures 16.59% of total expenditures2 (2003) Meat food expenditures 16.38% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.4342 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.3142 (2003) Food subgroups2 (2009) Beverages/ Breads/ Dairy tobacco cereals IE ED

0.578 −0.468

0.245 −0.198

0.495 −0.401

Fats/oils 0.271 −0.219

Fish

Fruits/ Meat Other veg

0.512 0.367 0.461 0.46 −0.414 −0.297 −0.373 −0.372

Population 4,156,1193 (2009) Population growth rate 1.1333 (2009) Net migration rate 4.76 migrants/1000 population3 (2008) Sources:

1

UF FAO (2009), 2 USDA (2009), 3 CIA (2009).

Table 1.14

Meat consumption data and selected demographic data for Germany

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

16 11

Mutton Poultry 0 0

12 13

Fish Fish (fresh water) (ocean) 2 2

15 14

Pork

Meat

54 54

85 84

Total food expenditures 13.09% of total expenditures2 (2003) Meat food expenditures 20.30% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.3092 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.2352 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.402 −0.325

0.153 −0.124

dairy

Fats/oils

0.351 −0.284

0.177 −0.143

Fish

0.362 0.259 0.328 0.327 −0.292 −0.209 −0.265 −0.264

Population 83,329,7583 (2009) Population growth rate −0.0533 (2009) Net migration rate 2.19 migrants/1000 population3 (2008) Sources:

1

Fruits/ Meat Other veg

UN FAO (2009),2 USDA (2009), 3 CIA (2009).

© Woodhead Publishing Limited, 2011

22

Processed meats

Table 1.15

Meat consumption data and selected demographic data for Spain

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

13 15

Mutton Poultry 6 5

24 30

Fish Fish (fresh water) (ocean) 1 2

42 47

Pork

Meat

52 66

99 121

Total food expenditures 17.52% of total expenditures2 (2003) Meat food expenditures 23.98% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.4422 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.3192 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.580 −0.469

0.232 −0.187

Dairy

Fats/oils

0.503 −0.407

0.263 −0.213

Fish

Fruits/ veg

Meat

Other

0.519 0.372 0.470 0.468 −0.420 −0.300 −0.380 −0.379

Population 40,491,0523 (2009) Population growth rate 0.0963 (2009) Net migration rate 0.99 migrants/1000 population3 (2008) Sources:

1

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

Table 1.16

Meat consumption data and selected demographic data for Russia

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

25 18

Mutton Poultry 2 0

10 16

Fish Fish (fresh water) (ocean) 2 3

12 18

Pork

Meat

15 16

55 52

Total food expenditures 34.35% of total expenditures2 (2003) Meat food expenditures 22.92% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.6172 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.3902 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.873 −0.706

0.403 −0.326

Dairy

Fats/oils

0.712 −0.576

0.428 −0.346

Fish

0.742 0.529 0.657 0.655 −0.600 −0.428 −0.532 −0.530

Population 140,702,0963 (2009) Population growth rate −0.4743 (2009) Net migration rate 0.28 Migrants/1000 population3 (2008) Sources:

1

Fruits/ Meat Other veg

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

23

respectively) as well as price elasticity of demand (−0.284, −0.286 and −0.265 respectively). They spend on average 15% of income on food and have slow natural and migrant population increased. Changes in meat consumption patterns would therefore be expected to be minor, which they are. Ireland had rapid natural and migrant population growth with incredible economic growth during 1994 to 2003. Income elasticity for meat was 30% higher in Ireland than in the United Kingdom, France and Germany. Meat consumption could be expected to increase and did so. Almost the opposite occurred in Russia. Russia had 43% higher income elasticity than Ireland, but no economic growth and perhaps even an economic contraction from 1994 to 2003. Natural and migrant population growth was negative. Little wonder that meat consumption decreased. Spain had very low natural and migrant population growth, but a strong economic growth rate that pushed up meat consumption. 1.5.3 Asia Japan posted a modest increase in meat consumption from 1994 to 2003 and behaved similarly to the well-developed European countries. South Korea increased meat consumption by 39% and China 50% from 1994 to 2003 as shown in Tables 1.17–1.19. Both countries had strong economic Table 1.17 Meat consumption data and selected demographic data for China Meat consumption kg/capita/year1 Year

Bovine

1994 2003

2 4

Mutton Poultry 1 2

6 10

Fish Fish (fresh water) (ocean) 6 10

18 25

Pork

Meat

26 35

36 54

Total food expenditures 13.04% of total expenditures2 (2003) Meat food expenditures 13.29% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.4252 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.3092 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.556 −0.449

0.218 −0.176

Dairy

Fats/oils

0.483 −0.391

0.249 −0.202

Fish

Fruits/ Meat veg

Other

0.498 0.356 0.451 0.450 −0.403 −0.288 −0.365 −0.364

Population 1,330,044,5443 (2009) Population growth rate 0.6293 (2009) Net migration rate −0.39 migrants/1000 population3 (2008) Note that meat consumption numbers are for China as well as population numbers, but elasticity numbers and food expenditure numbers are for Singapore. Sources: 1 UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

© Woodhead Publishing Limited, 2011

24

Processed meats

Table 1.18

Meat consumption data and selected demographic data for Japan

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

10 8

Mutton Poultry 0 0

13 15

Fish Fish (fresh water) (ocean) 5 5

71 66

Pork

Meat

15 18

40 43

Total food expenditures 14.88% of total expenditures2 (2003) Meat food expenditures 7.82% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.2932 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.2442 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.388 −0.314

0.160 −0.129

Dairy

Fats/oils

0.344 −0.270

0.179 −0.145

Fish

Fruits/ Meat Other veg

0.345 0.247 0.312 0.311 −0.279 −0.200 −0.252 −0.251

Population 127,288,4163 (2009) Population growth rate −0.1393 (2009) Net migration rate migrants/1000 population3 (2008) Sources:

1

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

Table 1.19 Korea

Meat consumption data and selected demographic data for South

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

8 12

Mutton Poultry 0 0

9 10

Fish Fish (fresh water) (ocean) 0 0

50 58

Pork

Meat

18 27

36 50

Total food expenditures 31.64% of total expenditures2 (2003) Meat food expenditures 12.69% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.4502 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.3242 (2003) Food subgroups2 (2009) Beverages/ Breads/ Dairy tobacco cereals IE ED

0.576 −0.466

0.187 −0.151

0.510 −0.412

Fats/oils 0.234 −0.189

Fish

0.524 0.374 0.478 0.477 −0.424 −0.302 −0.387 −0.385

Population 48,379,3923 (2009) Population growth rate 0.2693 (2009) Net migration rate migrants/1000 population3 (2008) Sources:

1

Fruits/ Meat Other veg

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

25

growth during the same period. Natural and migrant population growth rates for all three countries are low to negative and not a major factor in meat consumption pattern changes. It is perhaps more interesting to look at subcategories. Per capita beef consumption doubled from 2 kg to 4 kg in China, but pork increased by 9 kg. Beef consumption increased in South Korea as well from 8 kg to 12 kg. However, as in China, pork was the major driver of change with an increase of 9 kg.

1.5.4 Australia and New Zealand Both Australia and New Zealand have high natural and migrant population growth rates and Australia leads the world among developed nations in migrant population growth as revealed in Tables 1.20 and 1.21. Meat consumption increased from 1994 to 2003 in both countries but New Zealand’s growth rate was double Australia’s (20% versus 9%). However, Australia has five times the population of New Zealand.

1.5.5 General rules for all countries There are some general rule of thumb strategies for projecting and/or understanding meat consumption patterns for various countries. They break down as follows. Table 1.20 Meat consumption data and selected demographic data for Australia Meat consumption kg/capita/year1 Year

Bovine

1994 2003

42 46

Mutton Poultry 19 14

26 35

Fish Fish (fresh water) (ocean) 0 1

20 22

Pork

Meat

19 21

108 118

Total food expenditures 15.07% of total expenditures2 (2003) Meat food expenditures 16.91% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.3002 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.2282 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.388 −0.314

0.143 −0.115

Dairy

Fats/oils

0.340 −0.275

0.168 −0.136

Fish

1

Other

0.350 0.250 0.318 0.317 −0.283 −0.202 −0.257 −0.256

Population 21,007,3103 (2009) Population growth rate 1.2213 (2009) Net migration rate 6.34 Migrants/1000 population3 (2008) Sources:

Fruits/ Meat veg

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

© Woodhead Publishing Limited, 2011

26

Processed meats

Table 1.21 Zealand

Meat consumption data and selected demographic data for New

Meat consumption kg/capita/year1 Year

Bovine

1994 2003

20 26

Mutton Poultry 32 24

20 26

Fish Fish (fresh water) (ocean) 1 2

21 26

Pork

Meat

14 20

91 109

Total food expenditures 15.19% of total expenditures2 (2003) Meat food expenditures 13.87% of total food expenditures2 (2003) Income elasticity (ID) of food/beverages/tobacco 0.3942 (2003) Price elasticity (ED) of demand for food/beverages/tobacco −0.2912 (2003) Food subgroups2 (2009) Beverages/ Breads/ tobacco cereals IE ED

0.523 −0.423

0.217 −0.176

Dairy

Fats/oils

0.450 −0.364

0.242 −0.196

Fish

Fruits/ veg

Meat

Other

0.465 0.333 0.419 0.418 −0.376 −0.269 −0.339 −0.338

Population 4,173,4603 (2009) Population growth rate 0.9713 (2009) Net migration rate 2.62 migrants/1000 population3 (2008) Sources:

1

UN FAO (2009), 2 USDA (2009), 3 CIA (2009).

Developed nations • Income elasticity and price elasticity of demand are the most useful tools to forecast/explain changes in meat consumption. • Major policy changes or events produce major changes in consumption as BSE and foot and mouth disease proved in the early twenty-first century. • Population growth patterns are important and it is important to differentiate between natural and migrant growth. Developing nations • Income dominates changes in meat consumption. Strong consistent growth in economic activity increases meat consumption (China, Spain and Ireland) – ditto for decreases (Russia). • Population increases play a significant role in meat consumption changes (Ireland) – ditto for decreases (Russia).

1.6 Future trends in meat consumption Throughout history humans have consumed meat based primarily upon where they lived and how they evolved culturally. Only in the last century and since 2000 have we also found out that part of the reason humans liked meat involved the ability of the tongue to taste a specific amino acid. Also

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat

27

in the last century economic democracy and thus the rise of a middle class in numerous countries around the world produced major changes in meat consumption. To be sure, income is a major driver in future meat consumption as all countries show positive income elasticity. Additionally, for many emerging economies price is the most important variable. The author was involved with an evaluation of a poultry operation in Equatorial Guinea in the early 1980s. The cost to produce poultry was three times the cost of delivered dressed carcasses from Spain. Additionally, Equatorial Guinea had no infrastructure for processing, marketing or delivery. The economics of importation of poultry overwhelmed the economics of production such that it was impossible to develop a poultry industry in Equatorial Guinea. Rapidly growing economies have growing appetites for meat while mature economies have slower growth. Yet within the mature economies of Europe, the Americas, Japan, Australia and New Zealand, major drivers of changes in meat consumption, will likely center or luxury meat items (types, cuts, processing), health-related issues (both animal and human) and environmental concerns. In the United States and Canada high end prime beef is desired for the wave of new steak house restaurants as well as home consumption. Consumers in Europe want short farm miles, individual farmer identification and the ability to trace the point of production. Most of the developed economies have aging populations that increasingly are concerned about health and direct their food budgets likewise. Table 1.22 shows world meat consumption numbers and various subgroups of countries. The most rapid relative growth, of course, is in Table 1.22 World meat consumption kg/capita

World Developed1 Developing2 South Africa Developing Africa3 Asia Developed4 Developing5 Europe6 Canada and United States South America Central America and Caribbean Oceania7 USSR Europe8

1994

2003

% change

76 23 40 12

80 28 43 13

5.2 21.7 7.5 8.3

41 20 86 111 58 37 97 52

46 27 91 121 65 46 103 47

12.2 35.0 5.8 9.0 12.9 24.3 6.2 −9.6

Source: UN FAO (2009). 1 Composed of 52 countries, 2 122 countries, 3 50 countries, 4 Japan and Israel, 5 31 countries, 6 15 countries, 7 9 countries, 8 7 countries.

© Woodhead Publishing Limited, 2011

28

Processed meats

developing countries that have lower initial meat consumption habits versus developed countries. However, it is interesting to note the nominal growth as well. Developed nations increased their consumption by 4 kg per capita in 52 countries with a population of roughly 2 billion. Developing nations increased their consumption 5 kg per capita with a population of roughly 4 billion! Clearly the next decade will be filled with great opportunities for meat producers, processors and marketers as they segment and differentiate among developing nations, new middle class consumers and mature consumers throughout the world. Many of the new opportunities will come from circumstances and issues that did not exist just a decade ago. Consider for example the following: • Carbon. Climate change has certainly been around since the dawn of geological time but has only emerged during the early part of the twentyfirst century as an issue that has humans and their activities as part of the equation. Carbon accounting as well as greenhouse gas accounting will continue to be part of the meat production process as producers and processors deal with stocking densities including ‘free range’ versus ‘factory type’ operations. Additionally, the issue of eco-friendly meat production (i.e. rainforest or fragile ecosystems) will be part of the consumer decision process. • Organic. Almost as soon as modern agriculture began moving into first the mechanical era (early twentieth century) followed by the chemical era (mid twentieth century) and now the biological era (late twentieth century), groups of producers resisted the technological movements. The resistance was scarcely noticed by the marketplace until the labels ‘Organic’ and ‘non-GMO’ (genetically modified organisms) emerged. Reliable statistics are unavailable; however, it is believed that approximately 2% of the food market in North America is organic and approximately 5% in Europe. GMO food has been a marketing and policy issue far greater in Europe than in North America and most developing nations and will likely remain so for many years to come. Meat producers will continue to find market differentiation possibilities by labeling and adhering to non-conventional production processes. • Health. As consumers live longer, issues of the impact of food on health have come to the forefront in both food and healthcare industries. Nutritional information, functional foods and lifestyles enter into consumer choice. Probotics have found market niches primarily in Europe, especially in milk products. As the biological era of food production matures, information concerning production practices as well as the overall health of consumers will continue to be a major growth area. These trends are, of course, not exhaustive and more importantly are likely to be replaced by others. Consumer attitudes about meat (National Livestock & Meat Board) in 1992 were listed in rank ordering as follows:

© Woodhead Publishing Limited, 2011

Consumer demands and regional preferences for meat 1. 2. 3. 4. 5. 6.

29

Main meal must include meat Meat is best part of meal Meat is healthier than other foods Meat can fit into a reduced fat diet I am trying to avoid cholesterol Would buy more meat if it were less expensive

The list shows that almost two decades ago health was of concern to consumers but the main issues involved meat in diets and none of the hotbottom issues of today. No doubt in 20 years the trends and issues of today will be eclipsed by others. However, the old proverb of ‘In change there is opportunity’ has never been truer than today. Consumers have more money worldwide and will continue to shift and change what they want in meat. The opportunities have never been greater for those willing to adapt.

1.7 References bielik, p. and z. sajbidorova (2009) Elasticity of consumer demand on pork meat in the Slovak republic, Agric Econ Czeck, 55 catlett, l. and libbin, j. (2007) Risk Management in Agriculture, Thompson Delmar Learning cia (2009), www.cia.gov. heilig, g.k. (1999) China Food. Can China Feed Itself? IIASA international markets bureau (2009) Market and Industry Services Bank, Agriculture and Agri-Food Canada, www.canadabusiness.ca. lehrer, j. (2007) Proust was a Neuroscientist, Houghton Mifflin Company mbala, j.p. ayissi (1987) Short-run Demand for Goat Meat in Cameroon, INADER national livestock and meat board (1992), www.mlmb.org. pearson, a.m. and t.a. gillett (1999) Processed Meats, Aspen Publishers riley, g. (2009) Rising Demand For Inferior Goods, Tutor2U un. fao (2009), www.fao.gov. united states meat export federation (2009), www.usmef.org usda (2009), Economic Research Service, www.ers.usda.gov.

© Woodhead Publishing Limited, 2011

2 Processed meat products: consumer trends and emerging markets M. D. de Barcellos, Federal University of Rio Grande do Sul (EA/UFRGS), Brazil and K. G. Grunert and J. Scholderer, Aarhus Unversity, Denmark

Abstract: Processed meats have been under the spotlight, since consumers worldwide are facing a dilemma: how to keep pace with modern life, where the need for convenience, self-indulgence, quality and safety is uttermost, and still preserve naturalness of meat products? In this chapter we explore the consumer’s judgement of meat quality and the ongoing trends towards convenience and wellness (health and naturalness). New positioning strategies are suggested for the meat processing sector and opportunities from emerging markets are finally presented. Key words: consumer, processed meats, emerging markets, convenience, wellness.

2.1 Introduction: processed meats and modern life dilemmas Processed meats have been under the spotlight. Modified from their natural state for convenience and for safety reasons, processed meats are nowadays facing society’s scepticism: on the one hand, food processing can improve a consumer’s life by preserving and extending shelf-life, enhancing flavour and improving the consistency of some food products. On the other hand, processed meat products are usually high in fats, salt and preservatives such as nitrates, which are often accused of being unhealthy and disease related. Increasing risks of cancer and coronary conditions have been associated with their consumption (Verbeke et al., 2009). In addition, consumer trends indicate a shift towards wellness and an aversion to too much intervention in food (Beherens et al., 2009; De Barcellos et al., 2010; Verbeke et al., 2009; Bruhn, 2007). Therefore, consumers are facing a dilemma: how to keep pace with modern life, where the need of convenience, self-indulgence, quality

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

31

and safety is uttermost, and still preserve the naturalness whenever eating? Global food processing industries are also being challenged: not only are innovations absolutely necessary in such a competitive environment, but there is a strong need to comply with consumer trends and public regulations in the development of new food products. Thus, this chapter deals with processed meat products, consumer trends and emerging markets. Our first aim is to explore the consumer’s judgement of meat quality, investigating how they process intrinsic and extrinsic quality cues when judging meat quality. Secondly, the ongoing trends towards convenience and wellness (health and naturalness) are presented, leading to the following section on new positioning strategies for the meat processing sector. Ethical (such as fair trade, animal welfare and organics) and natural (healthy) positioning are discussed, as well as growing market opportunities for functional meat products, reduced-fat and reduced-salt meat products and meal solutions involving modern processing technologies, such as ‘smart’ packaging. Closing the chapter, opportunities from emerging markets are presented: we investigate the scenario of processed meats in Latin America (Brazil and Mexico), Russia and China. Finally, this chapter deals with future trends for the processed meat business, and sources of further information and advice are provided.

2.2 Consumer judgment of meat quality The basic mechanisms by which consumers form impressions about the quality of food products in general and meat products in particular are well known (Brunsø et al., 2005; Grunert, 1997, 2005; Grunert and Bech-Larsen, 2004). Research on meat products has mainly concentrated on consumer perception of the quality of fresh meat and to a lesser degree processed meat. We know that perceived quality is multidimensional, and that the main dimensions are sensory quality, healthiness, convenience and – for some consumers – process characteristics such as animal welfare and organic production. The latter play a larger role for fresh meat than for processed meat. We know that these qualities are mostly unknown to the consumer at the time of purchase: sensory quality and convenience are experience qualities, which can be evaluated only after the purchase during preparation and consumption, and healthiness and process characteristics are credence qualities, which even after the purchase are a question of communication and credibility, and cannot be evaluated by the consumer directly. As a consequence, before the purchase only quality expectations can be formed, and these will be based on the information available – usually called quality cues. It is common in the quality perception literature to distinguish between two types of cues: intrinsic (cues that are part of the physical product, like its appearance) and extrinsic (everything else, like brand name, advertising, information on origin and production method on the food label, shop where the product is sold).

© Woodhead Publishing Limited, 2011

32

Processed meats

We understand at least partly the mechanisms guiding the selection of cues by consumers to infer quality, namely cue selection based on diagnosticity (how predictive is the cue of the quality of interest) and accessibility (how familiar am I with the cue, so that I can make the right inferences; Dick et al., 1990; see also Cox, 1967). Quality perception of fresh meat has traditionally been largely based on intrinsic cues such as the colour of the meat, the visible fat and the cut. This is not mainly because consumers have been very competent in inferring quality from these cues (some studies suggest the opposite, see, e.g., Banovic et al., 2009; Brunsø et al., 2005; Bredahl et al., 1998), but because fresh meat is a largely unbranded product, and only a few extrinsic cues are available. The major exceptions have been the place of purchase, where consumers tend to believe that meat bought from a butcher is better than meat bought from a supermarket, and the origin of the meat, where meat of domestic origin is widely believed to be better (e.g., Bernués et al., 2003; Becker et al., 2000; Glitsch, 2000; Grunert, 1997). The situation is different with processed meat products. Processed meat products are often pre-packed, and many carry at least a rudimentary form of a brand. Building the right quality cues into the product is a major positioning issue and crucial for the success of new processed products in the market. Consider the example shown in Fig. 2.1, showing a chicken-based tapas product produced with the help of high pressure technology. The

Fig. 2.1 Chicken-based tapas product produced with high pressure technology (source: authors).

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

33

product contains a number of cues: the physical product is visible, allowing quality inferences to be made from the appearance. The product is described as a tapas product, ready to heat in the microwave, signalling convenience. It is described as a ‘light’ product, signalling healthiness. The package design, with the hand-written appearance, may remind some consumers of homemade products and traditional tapas bars. On the other hand, the text ‘produced by the help of high pressure technology’ (on the back) may signal the opposite, namely the use of modern, advanced technology. Thus all four quality dimensions – sensory, healthiness, convenience, process – are signalled on the product by quality cues. After the purchase, sensory qualities and convenience are experienced, while healthiness and process characteristics are still a matter of cue inferences. Most likely, quality perception after purchase, preparation and consumption will differ from the expectations formed before the purchase and partly due to the confirmation/disconfirmation about the sensory and convenience properties and partly due to new qualities becoming available – and others becoming less available – on the basis of which impressions on healthiness and process qualities can be formed. These changes need to be understood and managed, as they will determine whether the product will be bought again. This is especially important with first time purchases of new products, where the purchase is by definition based on expectations only, with no previous experience available. If the sensory experience does not live up to expectations, but also if the degree of convenience that has been promised is not in fact realised, it is unlikely that the product will be bought again. The more often a product has been bought, the more consumers are able to draw on their own experience with the product when making decisions about repurchase, and the less will the probability of repurchase depend on single experiences of deviation from expected quality. Over repeated purchases of the same product, the weight of the various quality dimensions may change. This goes especially for the relative weight of experience versus credence qualities. Over time, the qualities that can be experienced (sensory quality and convenience) may increase in weight at the expense of those qualities that remain invisible (healthiness and process qualities). This is especially a problem for functional meat products, which are positioned – and expected to command a price premium – on an added health benefit. If cues are not constantly provided that remind consumers of the health properties, consumers may forget about these and treat the product as just another food product that is not superior to other products in terms of its sensory or convenience properties. Quality perception of processed meat products is therefore not only a question of positive experiences when consumers consume these products, but to a very high degree also a question of the signalling of quality by means of information about the product at the point of purchase, during meal preparation, and during and after consumption.

© Woodhead Publishing Limited, 2011

34

Processed meats

2.3 Ongoing consumer trends This section will discuss two global consumer trends: convenience and wellness. On the surface, the two trends may appear as somewhat contradictory. A stereotype about convenience foods is that they are suited for the modern and time-pressured less health-conscious consumer; a solution for those consumers lacking time and culinary skills. At the same time, this modern time-pressured consumer is more aware of diet-related lifestyle diseases, looking for healthy and natural foods as a ‘smart’ alternative.

2.3.1 Convenience Convenience foods can be defined as commercially prepared foods designed for ease of purchase, preparation and consumption. The concept describes a variety of hot or cold foods and dishes that require little or no effort in preparation (Swiss Association for Nutrition, 2003; Anderson and Deskin, 1995). In general terms, two broad dimensions of convenience can be identified (Darian and Cohen, 1995): type and timing. The type of convenience dimension includes components related to the kind of effort that is being reduced: saving time, physical energy or mental energy. Consumers can save time by either spending less time in the consumption process overall (active time) or not having to wait, enjoying the availability of the product at a convenient time (passive time). The second dimension concerns the timing of convenience, that is, the stage of the consumption process at which convenience is obtained: when deciding what to eat, when purchasing food, preparing, consuming or cleaning up. Scholderer and Grunert (2005) combined these dimensions into a typology of convenience from a consumer point of view. Examples of the various combinations are shown in Table 2.1. Scholderer and Grunert (2005) also identified, from a food chain perspective, a further distinction between which actor provides which type of convenience to whom. In general, the food producer, the retailer or the food service provider can offer convenient solutions to consumers. Consumer demand for these solutions is driven by two distinct motivational factors: consumers’ perceptions of (a) time pressure and (b) their own monetary resources. Perceptions of time pressure motivate demand for convenience products, while perceptions of monetary resources motivate patronage of convenience stores and food service outlets. Both types of perceptions are positively influenced by the employment status of the adult household members: employment is associated with higher subjective time pressure and with higher perceived monetary resources. The presence of children is associated with higher subjective time pressure as well, but on the other hand also with lower monetary resources. In other words, the price levels in convenience stores and foodservice outlets tend to be perceived as not always affordable by families with children.

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets Table 2.1

Examples for the combination of type and timing of convenience

Consumption stage

What is being saved? Time

Physical energy

Planning

Habitual purchasing, weekly meal plans, intelligent fridge

Purchasing

One-stop shopping, home delivery

Preparation

Ready-made meals, eating out, microwave ovens One course meals stand-up food outlets One-way containers

Eating Disposal

35

Help in packaging and checking out, good parking facilities, home delivery Blenders and other kitchen appliances Pre-cut food, meat without bones Dish washer

Mental energy Products arranged by recipe in shop, space management, intelligent fridge Known store layout, automated reordering Clear instructions Familiar food, finger food Clear instruction about recycling*

Source: Scholderer and Grunert (2005, p. 106). * New example provided by the authors.

Several studies (Hunter and Worsley 2009; De Barcellos et al., 2010; Saba et al., 2008) suggest that other socio-demographic factors may also play an important role in the demand for convenience foods. In general, younger and more open-minded consumers tend to accept convenience foods more readily than older and more traditional consumers. Furthermore, ownership of the necessary kitchen appliances (microwave ovens) is a limiting factor, in particular in developing countries in which these appliances are not universally present in households. Despite the continuing growth of the processed meat products sector, fresh meat still dominates the supermarket. Innovations are mainly seen in the product packaging and seasoning (such as vacuum packaging and marinating), most of them coming from the poultry and pork chains. The beef chain still lags behind its competitors in terms of convenience, but the interest in new red meat products, particularly convenience-oriented products, has dramatically increased in recent years (Resureccion, 2003). Thus, ready meals and ready-to-cook products open up new opportunities for the meat processing industry. 2.3.2 Wellness At the dawn of the twenty-first century, the quest for wellness, a balance between good physical and mental health that results in an overall feeling

© Woodhead Publishing Limited, 2011

36

Processed meats

of well-being, is growing. Wellness can be achieved by a combination of proper diet, exercise and healthy habits. In that sense, the rise of nutrition science is changing the role of food. Food is not only required for body development, growth and maintenance but is also recognised to play a key role in the quality of life (Ashwell, 2002). Inadequate food habits are negatively impacting world societies in general. In Europe, obesity presents an unprecedented public health challenge with substantial economic implications deserving a strategic governmental approach (Pérez-Cueto et al., 2010). In Australia, for instance, half of the population is overweight or obese, leading to the development of the CSIRO Total Wellbeing Diet. This diet is aimed at minimising the health risks experienced by overweight Australians through better nutrition and weight management and draws upon some key health benefits of higher protein dietary patterns including assisting people lose weight without feeling excessively hungry (CSIRO, 2004). The diet is considered a success because it is compatible with eating habits of the population: Australians like higher levels of protein in their diet and the Total Wellbeing Diet advocates 200 g of lean red meat, fish and chicken as a daily part of the diet. Lean red meat (beef lamb or veal) is recommended four times a week, fish twice and chicken once. The idea behind it is that a moderated intake of lean meat combined with exercise and weight loss can contribute to the maintenance of well-being. Relationships between food/health and food/disease have been widely reported in the literature, and meat, in particular, has been at the core of much discussion. On the one hand, meat is nutritionally dense, hence an important source of a wide range of nutrients such as proteins, fats and vitamins (Verbeke et al., 2009). Despite a generally high nutritional value, the consumption of meat and processed meat products has been associated with a number of unfavourable health conditions, such as some types of cancer (Sato et al., 2006; Linseinsen et al., 2004) and coronary heart diseases (Kontogianni et al., 2008). Recent recommendations suggest that moderate consumption of fresh red meat and avoidance of processed high fat meat products are desirable for the prevention of colorectal cancers (Demeyer et al., 2008). The increasing concerns over health and wellbeing are boosting the trend towards ‘going natural’ worldwide. Studies show that people have a substantial preference for natural over processed or artificial food products (Verbeke et al., 2009; Rozin et al., 2004) and when confronted with two products that are chemically identical, but one of the two is natural and the other is artificial, people prefer the natural one (Tenbült et al., 2005). The meat sector still faces an additional challenge: vegetarianism, a former counter-cultural movement, is on the rise worldwide (Mogelonsky, 2005). Some 20–25% of adults in the United States reported that they usually or sometimes maintain a vegetarian diet (American Dietetic Association, 2003). A more recent survey held in the United States (Research&Markets,

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

37

2008) indicated that vegetarians and vegans are motivated by a number of different concerns, but, as a group, they cite animal welfare as the biggest primary motivator in choosing a vegetarian diet. This is in contrast to nonvegetarians, who clearly indicate that health is the primary and/or only motivator for meat-reducing behaviour. But other factors are also affecting meat consumption and consumer attitudes towards meat production. For instance Ghent, in Belgium, became the first city in the world to go vegetarian at least once a week (Herrel, 2009). The initiative of Ghent City Council is based on a United Nations study (FAO, 2006) alleging that livestock is responsible for nearly one-fifth of global greenhouse gas emissions. One way or another, the meat industry is feeling the impact of global societal changes. Hence, the unanswered question is: how can the meat industry successfully compete and in such a harsh environment? Not only is competition among producers of protein sources fierce, but consumers’ demand for wellness, health and naturalness is confronted with the need for convenience food. New positioning strategies emerge in this scenario and are going to be addressed in the next section.

2.4

New positioning strategies for the meat industry

The food industry has been evolving rapidly and creating solutions that can fit an ever-demanding consumer world. The ethical positioning of food products such as organics, fair trade and clean labelling, the rise of functional products, the launch of reduced-fat and reduced-salt products and the development of technological meal solutions represent some of the answers different consumer ‘tribes’ are looking for. These strategies are presented next.

2.4.1 Ethical positioning Ethical consumption relates to the intentional purchase of products and services that are produced ‘ethically’, without harming or exploiting humans, animals or the environment (Ethicalconsumer, 2009). Thus, it is highly dependent on subjective moral judgements, that is, the norms, values and beliefs which define the rightness or wrongness of consumption for an individual or community (Crane and Matten, 2004). First, because ethical consumption is contextual upon the time and place in which individuals live. Second, ‘the ethics of consumption depends on the consumer’s subjective view on ethics, and to some extent on their individual concerns’ (Cherrier, 2005, p. 126). Ethical consumption is nothing new. Since the 1970s, the increasing alert about the unsustainable way the environment was being exploited has gained momentum with consumers (Aguiar et al., 2008). Interestingly, many consumers still ‘seem to give little thought to the links between their

© Woodhead Publishing Limited, 2011

38

Processed meats

consumption behaviours and the process of food production’ (De Boer et al., 2009, p. 851). However, studies indicate that ethical concerns are growing and are decisively impacting on the choice of food products from specific consumer segments and niches (Krystallis et al., 2009; Vanhonacker et al., 2008; Brom, 2000). Environmental and societal concerns have also been motivating the search for more sustainable farming practices (Krystalis et al., 2009). In practice, consumers can express four main types of ethical buying (Ethicalconsumer, 2009), and this behaviour is particularly important from a food industry perspective (see Table 2.2). In the food industry, ethical positioning is of particular interest in the meat sector owing to the many challenges it faces. Negative environmental impact has been related to industrial animal production, since large amounts of waste (nitrogen, phosphorus, ammonia emissions) are generated in intensive animal production units. Ammonia is an environmental pollutant which causes nitrogen enrichment of the soil, and affects groundwater, surface water and the air. This can have detrimental effects on ecosystems (IvanovaPereva et al., 2008; Ye et al., 2007). Lately, the effects of beef production on global warming have been under investigation worldwide (e.g. Ogino et al.,

Table 2.2 Types of ethical buying, corresponding consumer behaviour and consequences for the food industry Type of ethical buying

Corresponding consumer behaviour

Consequences for the food industry

Positive buying

Favouring particular ethical products

Negative purchasing

Avoiding products that consumers disapprove of

Companybased purchasing

Targeting a business as a whole and avoiding all the products made by one company

Fully screened approach

Looking both at companies and at products and evaluating which product is the most ethical overall

Consumers buy food products labelled as fair trade, organic, free-range and/or ‘green’ Consumers reject certain food product categories, such as battery eggs or products coming from industrial or ‘factory farming’ systems (where animals are kept indoors, confined, typically at high densities) Consumers’ activism against companies that do not follow ethical standards (such as PETA against Kentucky Fried Chicken in the early 2000s owing to animal welfare reasons) Consumers that, for instance, choose companies that care for the environment and use ‘carbon neutral certificates’ or clean labelling

Source: adapted from Ethicalconsumer (2009).

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

39

2007). Better farm management and more efficient animal feeding practices can help reduce the carbon footprints, but there is the crucial need to preserve the environmentally friendly image of the food industry through sustainable actions that can actually ensure its positioning. For instance, the food processing industry could benefit by implementing more sustainable strategies associated with waste management. For example, the use of food processing by-products for animal feed would not only help food processors to save money, but could also prevent pollution and improve their image towards society and such a view is supported by the following statement; ‘Offering by-products for use as animal feed is an economical and environmentally sound way for food processors to reduce waste discharges and cut waste management costs’ (Crickenberger and Carawan, 1996). At variance with other traditional industrial sectors, the meat industry ‘disassembles’ carcasses. Therefore, waste reduction and efficient use of animal resources is of utmost importance to the meat industry. Consumers’ concerns about animal welfare can also impact on the ethical positioning of food companies, since industrial animal production has been associated with high stocking densities and indoor confinement of the animals. Such situations may lead to a negative impact on consumer attitudes towards industrial food products (De Boer et al., 2009; Vanhonacker et al., 2009, 2008, 2007; Boogard et al., 2006; Lassen et al., 2006; Marie, 2006; María, 2006; Frewer et al., 2005; Ngapo et al., 2004; Te Velde et al., 2002; Verbeke and Viane, 2000) with potentially negative consequences in terms of market outcomes and processed meat products’ acceptance. In that sense, the strategy to deliver food products that can satisfy the demands of the ethically conscious consumer is highly desirable for the meat industry: not only to guarantee its competitiveness in the long run, but also to promote a shift from the traditional perspective this industry generally holds to a more market oriented view. For instance, a global search on Mintel GNPD database held in July 2009 found only 541 meat products (beef, pork and poultry) in the ‘ethical and environmental claim category’. Some 203 meat products were launched between July 2008 and July 2009, indicating that the consumer awareness of health issues, environmental threats and social inequalities is therefore stimulating the strategic positioning and the launch of ethical meat products. Figure 2.2 presents examples of ethically positioned meat products launched globally.

2.4.2 Functional meat products The term ‘functional foods’ was first introduced in Japan in the mid-1980s and was further developed in the United States and in Europe, although nowadays there is a global, steadily growing market for functional foods. The concept refers to processed foods containing ingredients that, in addition to being nutritious, aid specific body functions, i.e. foods that provide a health benefit as well as nutrients. The rise of functional foods occurred

© Woodhead Publishing Limited, 2011

40

Processed meats

Fig. 2.2 Examples of ethically positioned meat products (source: Mintel Global New Product Database, 2009).

due the convergence of several factors: (a) the discovery of ingredients with health properties which could be incorporated into foods, (b) increasing awareness among consumers and industry of the link between diet and health, (c) a crowded and hypercompetitive food market, creating an imperative for food manufacturers to seek out new ways of differentiating their products, and (d) deterioration in consumers’ health, led by busy lifestyles with poor food choices and insufficient exercise (Euromonitor, 2004). Meat is often said to be ‘functional by nature’, owing to its privileged composition. Red meat is a rich source of proteins, iron, complex B vitamins, zinc, conjugated linoleic acid (CLA), and other important micro-nutrients. Nevertheless, in terms of current meat based functional products, the red meat industry faces a major challenge: functional foods require specialised niche marketing, where premium branding plays a big role. The business culture of the red meat industry, however, is rather, characterised by an emphasis on productivity growth and cost savings primarily due to economies of scale and scope (MLA, 2001). In the last decade, there has been some development of meat products with added functionality (but considerably less than other functional food products, such as dairy products, for example). In total, roughly 4100 functional and fortified products with meat ingredients have been launched globally between 2002 and 2008, as seen in Fig. 2.3. Approximately one-third of these products were explicitly positioned as functional, carrying a health claim. The remaining two-thirds were positioned as fortified, carrying a nutrition claim. Among all packaged foods and beverages with an explicit health and wellness positioning, the historically largest categories of products containing meat ingredients are (by rank): processed meat products,

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

41

Processed fish, meat and egg products Meals and meal centres Soups 146 289 223

110

Snacks

328 363 2587 462

Sauces and seasonings Dairy products

609 Bakery products

622 1939

Non-alcoholic beverages Baby food Sugar and gum confectionary Side dishes

Fig. 2.3 Category distribution of health and wellness-positioned foods and beverages containing meat ingredients (source: Mintel Global New Product Database, 2002–2008).

ready meals, soups, snacks, sauces and seasonings, dairy products, bakery products, non-alcoholic beverages, baby food, sugar and gum confectionery and side dishes. Figure 2.3 shows the distribution across categories of health and wellness-positioned foods and beverages containing meat ingredients. The fastest growth from 2007 to 2008 can currently be observed in the two categories: ready meals (62% increase in 2008 compared to 2007) and baby foods (62% increase in 2008 compared to 2007). Japan is the traditional lead market for virtually all functional food categories. Products such as functional burgers and sausages have been available there for some time. Slightly later, a wide variety of meat products with added functionality were introduced in the United States, with considerably more success than in Japan. Per capita consumption of red meat is still relatively low in Japan, mainly due to the high importance of other protein sources in the traditional diet that can be considered ‘functional by nature’ (fish, seafood, soybeans). Therefore, the United States can now be considered the lead market for functional meat products. Finally, an interesting strategy for the meat, ingredients and general food processing industries might be the extraction of functional ingredients and bioactive compounds from meat for use in food products, but in other product sectors also, including; food packaging materials, cosmetics and

© Woodhead Publishing Limited, 2011

42

Processed meats

pharmaceuticals. In addition to the traditional essential nutrients, meat and meat products contain a number of bioactive substances which have potentially beneficial effects on human health, such as l-carnitine, coenzyme Q10, carnosine, anserine, taurine, creatine, glutathione, alpha lipoic acid, CLA and bioactive peptides (Schmidt, 2009). Carnosine, for instance, is being viewed as one of the most important supplements for improving longevity (Hipkiss, 1998).

2.4.3 Reduced-fat and reduced-salt products One of the major problems facing today’s society relates to food intake: overall, individuals are eating too much and in the wrong way. Recently, obesity and related health conditions (such as high blood cholesterol and pressure) have been negatively affecting consumers’ well-being and contributing to a continuously shift in food eating habits. The World Health Organization (WHO, 2009) advocates that dietary intake of fats strongly influences the risk of cardiovascular diseases. Specifically, the intake of saturated fatty acids is directly related to cardiovascular risk. Therefore, the target is to restrict the intake of saturated fatty acids to less than 10% of daily energy intake and the intake of trans fatty acids (hydrogenated oils and fats) to less than 1%. This recommendation is especially relevant in developing and emerging countries where low cost hydrogenated fat is frequently consumed. Usually, animal fats are considered less desirable in the diet due to the degree of saturation. Weight-conscious consumers also tend to avoid food products with high fat content (McKeith and Merkel, 1991). The fact is that fat content is usually high in processed meat products: in traditional frankfurters it is 20–30%, ‘nuggets’ 20–25%, salami 30–50% and beef patty 20–30% (Colmenero, 2003), which contributes to the ‘unhealthy’ image processed meat products have in the eyes of many consumers. And here lies another challenge to food industry: in spite of being undesired by most consumers and execrated by the media and health organisations, fat is a key ingredient in meat processing. Fat content strongly affects product characteristics such as flavour, juiciness, texture, handling and heat transfer (Colmenero, 2003). Hence, when reformulating processed meat products to cope with trends towards health positioning, both fat reduction and modification of fatty acid composition should be taken in account. To simply reduce fat or replace it with another type does not seem to be an option: it is absolutely necessary to join technical expertise and innovation in food technology. Yet, one cannot forget that the need to provide transparent information regarding the nutritional content of food products is a growing trend and it is changing consumer demand. Consumers are more interested in product information and in healthy options. Consequently, there appears to be a growing requirement for consumer education. This would help individuals to develop the

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

43

ability to decide and choose food products intelligently, as well as to demand safe, reliable and good quality food products. From the supply side, the food industry has already commenced the process of reformulating existing product formats. Processed meat products currently on the market offer lower nitrate and fat contents, or a higher content of long chain poly unsaturated fatty acids (Verbeke et al., 2009). On the Mintel GNPD database (2009), we found 4012 processed meat products (beef, pork and poultry-based products) positioned as low/no/reduced fat and transfat, and low/no/reduced sodium. Some 534 of these products were launched globally in 2008, and 327 were launched between January and July 2009. Interestingly, in spite of such strong trends towards healthy eating, there are opportunities for traditional, old-fashioned processed meat products. One could argue that the market success of food products with geographical indication is due to their suitability in responding to consumers needs in terms of genuineness and authenticity in the face of food massification. For example, ‘Prosciutto Toscano PDO’ (Protected Denomination of Origin) is a ham made only by pigs belonging to specific breeds, reared in Tuscany and with dry salting process which can only be carried out in this region. The product is one of the growing leaders of the Italian ham market (Belletti et al., 2007). In short, consumers are multifaceted: they demand healthy foods, yet surrender to indulgency. The food industry must be aware that such tradeoffs arise with consumers on a daily basis. Perhaps the offer of ‘healthy indulgency’ could be a strategic way to satisfy their needs. However, it is imperative that if an approach towards developing novel meat products is centred around ‘healthy indulgency’, then products meeting this demand will need to be developed using a sensory science approach that addresses the wants and desires of the consumers, rather than simply addressing product development as merely a niche product gap filler (Dr Joe P. Kerry, personal communication).

2.4.4

Meal solutions: making consumers’ life easier through processing technologies and ‘smart’ packaging Meal solutions are fully or partially prepared foods that aim to solve growing consumer needs: lack of time, lack of skill and lack of desire to prepare food (Larson, 1998). In general, from an industry perspective, meal solutions add value and usually improve safety and shelf-life of food products. By definition, meal solutions should be quick, easy to prepare and easy to assemble (Kramer, 1997). Larson (1998) considers meal solutions and home meal replacements (HMR) as synonymous, the latter being some kind of prepared food purchased away from home for at-home consumption. Meal solutions can be divided in four main subcategories: (a) ready-

© Woodhead Publishing Limited, 2011

44

Processed meats

to-eat, (b) ready-to-heat, (c) ready-to-cook, and (d) ready-to-prepare items. In any of the cases, meal solutions are inextricably linked to food technology (industry level), distribution channels (retail/food service level), at-home preparation and availability of certain household appliances, such as microwave oven, freezer and others (domestic level). Interestingly, the incidental advent of the microwave oven in the 1940s (Gallarwa, 2009) was the starting point for many advances in food technology. The microwave reduced the time needed for preparing and cooking food and created the need for ‘quick food’ and ‘ready meals’ (Moran, 2005). But it was not until the late 1970s that consumers accepted this technology: it took nearly 30 years for the benefits of convenience to outweigh its perceived risks. Over time, other important food technologies besides microwaves have contributed to the increasing space needed for processed and convenience foods in the supermarket shelves: cooling, freezing, chilling and packaging are only a few examples of technological industry applications that are shaping food eating habits worldwide. Recently, emerging food technologies such as high pressure processing and pulsed electric field have been introduced at food industry level (Nielsen et al., 2009). Both methods are used for processing food without using heat and are suitable for meat products. In high pressure processing the product is subjected to pressure that inactivates most microorganisms. In pulsed electric fields electric impulses damage cell components and again inactivate most microorganisms. Food quality and natural freshness are preserved, producing nutritious and safe-to-eat foods and extending microbiological shelf-life without using chemical additives. These technologies clearly match the presented ongoing trends, but they are expected to be 10–20% more expensive than the products that are on the market today (Nielsen et al., 2009). Another challenge for these and other technologies lies in the fact that they have been developed primarily to address food safety concerns and shelf-life issues pertaining to the microbiology of foods. However, the use of such processing conditions to deliver microbiological stability often conflicts with other equally important product attributes, which for the most part have largely been ignored, such as those of chemical stability and sensorial acceptability (Dr Joe Kerry, personal communication). Thus, their success will basically depend on how consumers perceive these novel food technologies in terms of benefits and willingness-to-pay and on the further industrial development of processing innovation. Finally, meal solutions presuppose adequate packaging: they can be frozen, chilled, fresh, hot or a combination of those. Packaging is a strategic tool for food companies: it provides adequate portability (to make sure that the product will arrive intact at home) and signals to consumers not only branding, but also quality cues (such as labels and certifications). Packaging material can increase the perception of freshness and quality of the product and definitely can say something about market positioning. For instance,

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

45

‘free range, organic chicken nuggets’ can be packed into recyclable trays, signalling that the food industry is aware of environmental and sustainable issues. In the food sector, a conventional package can be made ‘smart’ by radio frequency identification (RFID), benefiting the supply chain through track & trace mechanisms (see e.g. Aguiar et al., 2010). A package can also be made ‘smart’ by consumer-driven benefits that enhance the usability of the product. For instance, time–temperature food quality labels, self-heating and cooling containers, cartons with electronic displays indicating use-by dates and information about the nutritional qualities and origin of the product in numerous languages (Perkowski, 2009). Innovative packaging in the meat sector is an emerging and promising field. At global level we found 51 products on the Mintel GNPD database (2009) with an explicit claim of ‘innovative package’. The leading countries in innovative packaging are the USA, Italy, France, the UK and Germany. Among the innovations available in the market, the ones indicated in Table 2.3 illustrate some ‘smart packaging’ characteristics and trend categories where they belong. Overall, understanding the relationship between consumption behaviour and meal solutions is of great interest for the food industry and retailers, and as such can help in the development of new food products and intelligent packaging. In that matter, market evolution must run side by side with food technology advances in order to keep the supply and demand balance.

2.5 Emerging markets In the early nineteenth century, the German statistician Ernst Engel established a relationship between income growth and food choice known as ‘Engel’s law’: according to this postulate, as income rises, the proportion of income spent on food falls. At the same time, as income increases, consumers shift consumption patterns from starchy staple foods towards foods with greater protein content, which are more expensive per calorie. As households achieve higher incomes, expenditure on high-value added foods increases. In emerging markets such as Russia, China, Brazil and Mexico, this trend is particularly marked. Figure 2.4 shows historical growth rates in processed meat sales in these markets. However, such trends do not necessarily occur simultaneously, and they do not necessarily follow the same pattern. Figure 2.5 shows a breakdown (by category) of all new food products containing meat ingredients that were launched between 2004 and 2009 in Russia, China, Brazil and Mexico. While the two Latin American countries and China show relatively similar differentiation patterns, a different picture can be observed in Russia. Although the Russian market grows at double-digit rates in terms

© Woodhead Publishing Limited, 2011

46

Processed meats

Table 2.3 Processed meat products, ‘smart packaging’ characteristic and respective trend category Processed meat product Poultry sausages and ham Sliced roast chicken

Fresh, boneless, skinless chicken Ready-to-heat products

Hot-dog sausages

Meat products

Lean pork products (chilled) Beefburger

Half chicken, seasoned and ready to oven roast

‘Smart’ packaging characteristic

Trend category

Innovative chip on the package shows if the product can be consumed; when its centre turns black, the product is not suitable for eating The pack is aluminium-free: it can be recycled as plastic and can have a see-through window if the content is not photosensitive. In 2001 the package won the World Star award for its environmental-friendliness, quality and design Space-saving packaging, sealed in individual pouches to assure a clean and safe transition from the package to preparation • Microwaveable flexible pack, stand-up pouch ready to eat in a couple of minutes • Atmosphere protective stand-up pouch with an easy opening and a resealable plastic zip Frozen hot dog sausage in a crisp potato coating, suitable for preparing in a frying pan, a conventional or microwave oven. Individual sausages are packaged within a paperboard box. Each sausage has an individual ‘take away’ paperboard holder to prevent fingers from getting burnt Gas flush packaging. This method is said to preserve the life of the product and also enable the product to be presented in an appealing manner No preservatives, just a lemon juice flavouring that helps keep it fresh. Innovative vacuum pack film from that eliminates leaks Burger shaped like a hot dog, making it easy to grill on roller-style hot dog grills. Packaged in biodegradable trays which are made from wood derivatives (a type of wood pulp) Tub and a lid that peels off during the cooking and protects the oven from projections. The chicken is free-range, bred with 80% cereal minimum

Safety

Examples extracted from Mintel GNPD database (2009).

© Woodhead Publishing Limited, 2011

Sustainability (recycling)

Safety

Convenience (save cooking and cleaning time)

Convenience (save cooking and cleaning time)

Safety, shelf-life, visual appeal Naturalness, palatability and visual appeal Convenience (innovative shaping) and sustainability (biodegradable) Convenience (save cooking and cleaning time) and sustainability

Year-on-year growth: processed meat sales (retail value, current prices)

Processed meat products: consumer trends and emerging markets

47

30.0% 25.0% 20.0% Russia

15.0% China

10.0%

Brazil Mexico

5.0% 0.0%

2001–2 2002–3 2003–4

2004–5 2005–6 2006–7 2007–8 Period

Fig. 2.4 Year-on-year growth in processed meat sales in key emerging markets (source: Euromonitor Global Market Information Database, 2001–2009).

of value sales, product differentiation has still only reached a level comparable to that in the other three key emerging markets four to five years earlier.

2.6 Future trends In this chapter, we presented ongoing consumer trends and discussed the threats and opportunities processed meat products face in traditional and emerging markets. First of all, we believe that quality perception of processed meat products is a complex combination of positive experiences when consuming the product and the signalling of useful information about the product at the point of purchase, during meal preparation, and during and after consumption. There is also a growing need for transparency of nutritional qualities due to more nutrition labelling. Secondly, although convenience and wellness might appear as somewhat contradictory trends, both find space in global, modern food consumer markets. Positioning strategies encompassing ethical (fair trade, organics, free range), healthy (naturalness, functional meat products, reduced-fat and reduced-salt meat products) and/ or convenience dimensions (meal solutions and ‘smart’ packaging alternatives) increase the chances of success of processed meat products. Emerging markets in Latin America (Brazil and Mexico), Russia and China, among others, are forecast to enlarge further and consequently, constitute real opportunities for the rise in the consumption of processed meat products. It is predicted that our current global meat consumption of around

© Woodhead Publishing Limited, 2011

Number of new product variants

48

Processed meats 100 90 80

Baby food Processed meat products

60

Meals and meal centres

50

Soup

40

Side dishes

30

Snacks

20

Sauces and seasonings

10

Savoury spreads

0

Number of new product variants

Russia

70

2004

2005

2006

2007

2008

1400 1200

China

Meals and meal centres

1000

Processed meat products Snacks

800

Soup Sauces and seasonings

600

Bakery Side dishes

400

Baby food Breakfast cereals

200

Savoury spreads

0

Number of new product variants

2004

2005

2006

2007

2008

800 700 600

Processed meat products

Brazil

Meals and meal centres

500

Sauces and seasonings Soup

400

Snacks

300

Savoury spreads Side dishes

200

Bakery

100

Baby food

0

Number of new product variants

2004

2005

2006

2007

2008

600 500

Processed meat products

Mexico

Meals and meal centres

400

Soup Baby food

300

Side dishes Sauces and seasonings

200

Snacks Bakery

100

Savoury spreads

0 2004

2005

2006

2007

2008

Fig. 2.5 Newly launched products with meat ingredients, broken down by category (source: Mintel Global New Product Database, 2004–2009).

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

49

280 million tons per year will double by 2050 due to an ever-growing population possessing higher incomes (Worldwatch Institute, 2011). Hence, despite the global ‘stock market crash’, the meat industry, as well as the general food industry worldwide should remain innovative and consumer-driven.

2.7 Sources of further information and advice In this chapter, we have dealt with many contemporary and cross-cultural issues from a food consumer behaviour perspective. Therefore, for further information, we advise the reader to look for multidisciplinary approaches that can cover the vast research world of food product consumption. There are great books that provide useful approaches and background information about the topics we discussed, and some are indicated below: Frewer L, Risvik E and Schifferstein H (eds) (2001), Food, People and Society: A European Perspective of Consumers’ Food Choices, Springer, Berlin, Germany. Frewer L and Van Trip H (eds) (2007), Understanding consumers of food products, Woodhead Publishing Ltd, Cambridge, UK. Lindgreen A, Hingley M K and Vanhamme J (eds) (2009), The Crisis of Food Brands Sustaining Safe, Innovative and Competitive Food Supply, Gower Publishing, Farnham, UK. Lindgreen A and Hingley M K (eds) (2009), The New Cultures of Food: Marketing Opportunities from Ethnic, Religious and Cultural Diversity, Gower Publishing, Farnham, UK. MacFie H (ed) (2007), Consumer-led food product development, Woodhead Publishing Ltd, Cambridge, UK. The peer-reviewed journals Food Quality and Preference, Appetite, Livestock Science and Meat Science constitute valuable sources for further readings. Finally, the following websites will provide market information and precious statistics to help understanding the ongoing consumer trends in global and emerging markets. www.euromonitor.com www.datamonitor.com www.mintel.com www.IBGE.gov.br www.stats.gov.cn/enGliSH/

2.8 References aguiar l k, vieira l m, ferreira g c and de barcellos m d (2008), ‘The impact of retailers own brand Fair Trade products on developing countries producers’, in 8th International Conference on Management in Agri-food Chains and Networks, Ede-Wageningen, Proceedings, Wageningen Press, Wageningen.

© Woodhead Publishing Limited, 2011

50

Processed meats

aguiar l a k, brofman-epelbaum f and de barcellos m d (2010), ‘Are consumers ready for RFID? The dawn of a new market orientation era’, in Lindgreen A, Hingley M, Harness D and Custance P (Eds), Market orientation: transforming food and agribusiness around the customer, Gower Publishing Ltd, Farnham, UK, 245–261. american dietetic association (2003), ‘Position of the American Dietetic Association and Dietitians of Canada: vegetarian diets’, ADA Reports, June, 103, 6, available from: http://www.lpda.pt/vegetarianismo/ada_dc_veg.pdf [accessed 17 November 2008]. anderson b and deskin j (1995), The Nutrition Bible: The Comprehensive, NoNonsense Guide to Foods, Nutrients, Additives, Preservatives, Pollutants, and Everything Else We Eat and Drink, William Morrow & Co, New York. ashwell m (2002), Concepts of Functional Foods, ILSI Europe Concise Monograph series, ILSI Press, Brussels, Belgium. banovic m, grunert k g, barreira m m and fontes m a (2009), ‘Beef quality perception at the point of purchase: a study from Portugal’, Food Quality and Preference, 20, 335–342. becker t, benner e and glitsch k (2000), ‘Consumer perception of fresh meat quality in Germany’, British Food Journal, 102, 246–266. beherens j h, barcellos m n, frewer l j, nunes t p and landgraf m (2009), ‘Brazilian consumer views on food irradiation’, Innovative Food Science and Emerging Technologies, 10, 383–389. belletti g, burgassi t, marescotti a and scaramuzzi s (2007), ‘The effects of certification costs on the success of a PDO/PGI. 2007’, in Theuvsen L et al. (Eds), Quality Management in Food Chains, Wageningen Academic Publishers, Wageningen, 107–121. bernués a, olaizola a and corcoran k (2003), ‘Extrinsic attributes of red meat as indicators of quality in Europe: an application for market segmentation’, Food Quality and Preference, 14, 265–276. boogaard b k, oosting s j and bock b b (2006), ‘Elements of societal perception of farm animal welfare: a quantitative study in The Netherlands’, Livestock Science, 104, 13–22. bredahl l, grunert k g and fertin c (1998), ‘Relating consumer perceptions of pork quality to physical product characteristics’, Food Quality and Preference, 9, 273–281. brom f w (2000), ‘Food, consumer concerns, and trust: food ethics for a globalizing market’, Journal of Agricultural and Environmental Ethics, 12 (2), 127–139. bruhn c m (2007), ‘Enhancing consumer acceptance of new processing technologies’, Innovative Food Science and Emerging Technologies, 8, 555–558. brunsø k, bredahl l, grunert k g and scholderer j (2005), ‘Consumer perception of the quality of beef resulting from various fattening regimes’, Livestock Production Science, 94, 83–93. cherrier h (2005), ‘Using existential-phenomenological interviewing to explore meanings of consumption’, in Harrison R, Newholm T and Shaw D (Eds), The Ethical Consumer, Sage Publication, London. colmenero j (2003), ‘Fat reduction strategies for processed meats’, available from: http://www.preparedfoods.com/Articles/Feature_Article/6460dfd391788010Vgn VCM100000f932a8c0 [accessed 11 September 2008]. cox d f (1967), ‘The sorting rule model of the consumer product evaluation process’, in Cox D F (Ed.), Risk Taking and Information Handling in Consumer Behaviour, Graduate School of Business Administration, Harvard University, Boston, MA, 324–369. crane a and matten d (2004), Business Ethics: A European Perspective, Oxford University Press, Oxford.

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

51

crickenberger r g and carawan r e (1996), ‘Using food processing by-products for animal feed’, North Carolina Cooperative Extension Service Publication Number CD-37, USA, available from: http://www.bae.ncsu.edu/programs/extension/publicat/wqwm/cd37.html [accessed 24 August 2010]. csiro (2004), ‘How the total wellbeing diet was researched’, CSIRO, Australia, available from: http://www.csiro.au/science [accessed 11 July 2009]. darian j c and cohen j (1995), ‘Segmenting by consumer time shortage’, Journal of Consumer Marketing, 12, 32–44. de barcellos m d, kügler j o, grunert k g, van wezemael l, pérez-cueto f j, ueland ø and verbeke w (2010), ‘European consumers’ acceptance of beef processing technologies: a focus group study’, Innovative Food Science and Emerging Technologies, 11, 721–732. de boer j, boersema j j and aiking h (2009), ‘Consumers’ motivational associations favouring free-range meat or less meat’, Ecological Economics, 68, 850–860. demeyer d, honikel k and de smet s (2008), ‘The World Cancer Fund report 2007: a challenge for the meat processing industry’, Meat Science, 80, 953–959. dick a, chakravarti d and biehal g (1990), ‘Memory-based inferences during consumer choice’, Journal of Consumer Research, 17, 82–93. ethicalconsumer (2009), ‘Ethical consumer: a beginners guide’, available from: http://www.ethicalconsumer.org/Portals/0/Downloads/Introduction_booklet1.pdf [accessed 11 July 2009]. euromonitor (2004), ‘The world market for functional food and beverages’, available from http://www.euromonitor.com [accessed 11 October 2008]. fao (2006), Livestock’s long shadow: environmental issues and options, available from: http://www.fao.org/docrep/010/a0701e/a0701e00 [accessed 17 May 2009]. frewer l j, kole a, van de kroon s m a and de lauwere c (2005), ‘Consumer attitudes towards the development of animal-friendly husbandry systems’, Journal of Agricultural and Environmental Ethics, 1, 1–23. gallawa j c (2009), ‘Who invented microwaves?’, available from: http://www. gallawa.com/microtech/history.html [accessed 15 October 2009]. glitsch k (2000), ‘Consumer perceptions of fresh meat quality: cross-national comparison’, British Food Journal, 10, 177–194. grunert k g (1997), ‘What’s in a steak? A cross-cultural study of the quality perception of beef’, Food Quality and Preference, 8, 157–174. grunert k g (2005), ‘Food quality and safety: consumer perception and demand’, European Review of Agricultural Economics, 32, 369–391. grunert k g and bech-larsen t (2004), ‘Consumer perception of meat quality and implications for product development in the meat sector: a review’, Meat Science, 66, 259–272. herrel e (2009), ‘Where’s the beef? Ghent goes vegetarian’, Time Online, available from http://www.time.com/time/world/article/0,8599,1900958,00.html [accessed 20 June 2009]. hipkiss a r (1998), ‘Carnosine, a protective, anti-aging peptide?’ International Journal of Biochemestry and Cell Biology, 30, 863–868. hunter w and worsley t (2009), ‘Understanding the older food consumer. Present day behaviours and future expectations’, Appetite, 52, 147–154. ivanova-pereva s g, aarnink a j a and verstegen m w a (2008), ‘Ammonia emissions from organic housing systems with fattening pigs’, Biosystem Engineering, 99, 412–422. kontogianni m d, panagiotakos d b, pitsavos c, chrysohoou c and stefanadis c (2008), ‘Relationship between meat intake and the development of acute coronary syndromes: the CARDIO2000 case-control study’, European Journal of Clinical Nutrition, 62 (2), 171–177.

© Woodhead Publishing Limited, 2011

52

Processed meats

kramer j (1997), ‘A meal-solutions tsunami is blowing in’, Brandweek, 38(5), 16–17. krystallis a, de barcellos m d, kügler j o, verbeke w and grunert k g (2009), ‘Attitudes of European citizens towards pig production systems’, Livestock Science, doi:10.1016/j.livsci.2009.05.016 larson r b (1998), ‘The home meal replacement opportunity: a marketing perspective’. The Retail Food Industry Center, University of Minnesota, TRFIC Working Paper 98-01, January. lassen j, sandoe p and forkman b (2006), ‘Happy pigs are dirty! Conflicting perspectives on animal welfare’, Livestock Science, 103 (3), 221–230. linseinsen j, rohrmann s and norat t (2004), ‘Dietary intake of different types and characteristics of processed meat which might be associated with cancer risk – results from the 24-hour diet recalls in the European Prospective Investigation into Cancer and Nutrition (EPIC)’, Public Health Nutrition, 9, 449–464. mckeith f k and merkel r a (1991), ‘Technology of developing low-fat meat products’, Journal of Animal Science, 69, 116–124. maría g a (2006), ‘Public perception of farm animal welfare in Spain’, Livestock Science, 103 (3), 250–256. marie, m (2006), ‘Ethics: the new challenge for animal agriculture’, Livestock Science, 103 (3), 203–207. mla (2001), Functional Food Report, Meat and Livestock Australia, available from http://www.mla.com.au [accessed 10 March 2009]. mogelonsky m (2005), ‘New product trends category analysis: advancing vegetarianism’, available from: http://www.preparedfoods.com/Articles/Feature_Article/ c4b1279255788010VgnVCM100000f932a8c0 [accessed 25 April 2009]. moran j (2005), ‘Hum, ping, rip: the sounds of cooking’, New Statesman, 134 (4723), 34–35. ngapo t m, dransfielda e, martina j f, magnusson m, bredahl l and nuted g r (2004), ‘Consumer perceptions: pork and pig production. Insights from France, England, Sweden and Denmark’, Meat Science, 66 (1), 125–134. nielsen h b, sonne a-m, grunert k g, banati d, póllak-tóth a, lakner z, olsen nv, zontar t p and peterman m (2009), ‘Consumer perception of the use of highpressure processing and pulsed electric field technologies in food production’, Appetite, 52, 115–126. ogino a, orito h, shimada k and hirooka h (2007), ‘Evaluating environmental impacts of the Japanese beef cow–calf system by the life cycle assessment method’, Animal Science Journal, 78 (4), 424–432. pérez-cueto f j a, verbeke w, de barcellos, m d, kehagia o, chryssochoidis g, scholderer j and grunert k g (2010), ‘Food-related lifestyles and their association to obesity in five European countries’, Appetite, 55 (1), 156–162. perkowski f (2009), ‘Smart packaging’, available from: http://www.packaging-online. com/paperboard-features/smart-packaging [accessed 03 November 2009]. research&markets (2008), ‘Vegetarian consumer trends: vegetarians and vegan consumers’, available from: http://researchandmarkets.net/reportinfo.asp?cat_ id=0&report_id=614204&q=vegetarian&p=1 [accessed 02 April 2009]. resurreccion a v a, (2003), ‘Sensory aspects of consumer choices for meat and meat products’, Meat Science, 66, 11–20. rozin p, spranca m, krieger z, neuhaus r, surillo d, swerdlin a and wood k (2004), ‘Natural preference: instrumental and ideational/moral motivations, and the contrast between foods and medicines’, Appetite, 43, 147–154. saba a, messina f, turrini a, lumbers m and raats m (2008), ‘The Food in Later Life Team. Older people and convenience in meal preparation: A European study on understanding their perceptions towards vegetable soup preparation’, International Journal of Consumer Studies, 32, 147–156.

© Woodhead Publishing Limited, 2011

Processed meat products: consumer trends and emerging markets

53

sato y, nakaya n, kuriyama s, nishino y, tsubono y and tsuji i (2006), ‘Meat consumption and risk of colorectal cancer in Japan: The Miyagi Cohort Study’, European Journal of Cancer Prevention, 15, 211–218. schmidt a (2009), ‘Bioactive substances in meat and meat products’, Fleischwirtschaft, 89 (7), 83–90. scholderer j and grunert k g (2005), ‘Consumers, food and convenience: the long way from resource constraints to actual consumption patterns’, Journal of Economic Psychology, 26, 105–128. swiss association for nutrition (2003), ‘Convenience foods’, available from http:// www.healthandage.com/?q=archive/2434 [accessed 20 April 2009]. te velde h t, aarts n and van woerkum c (2002), ‘Dealing with ambivalence: farmers’ and consumers’ perceptions of animal welfare in livestock breeding’, Journal of Agricultural and Environmental Ethics, 15 (2), 203–219. tenbült p, de vries n k, dreezens e and martijn c (2005), ‘Perceived naturalness and acceptance of genetically modified food’, Appetite, 45, 47–50. vanhonacker f, verbeke w, van poucke e and tuyttens f a m (2007), ‘Segmentation based on consumers’ perceived importance and attitude toward farm animal welfare’, International Journal of Sociology of Food and Agriculture, 15 (3), 91–107. vanhonacker f, verbeke w, van poucke e and tuyttens f (2008), ‘Do citizens and farmers interpret the concept of farm animal welfare differently?’, Livestock Science, 116, 126–136. vanhonacker f, verbeke w, van poucke e, buijs s and tuyttens f (2009), ‘Societal concern related to stocking density, pen size and group size in 863 farm animal production’, Livestock Science, 123, 16–22. verbeke w and viane j (2000), ‘Ethical challenges for livestock production: meeting consumer concerns about meat safety and animal welfare’, Journal of Agricultural and Environmental Ethics, 12, 141–151. verbeke w, pérez-cueto f j a, de barcellos m d, krystallis a and grunert k g (2009), ‘European citizen and consumer attitudes and preferences regarding beef and pork, Meat Science, doi:10.1016/j.meatsci.2009.05.001. world health organization (2009), ‘Recommendations for preventing cardiovascular diseases’, available from: http://www.who.int/dietphysicalactivity/publications/trs916/en/gsfao_cvds.pdf [accessed 10 December 2009]. worldwatch institute (2011), ‘Meat production continues to rise’, Product number VST116, available from: http://www.worldwatch.org/node/5443 [accessed 14 March 2011]. ye z, li b, cheng b, chen g, zhang g, shi z, wei x and xi l (2007), A concrete slatted floor system for separation of faeces and urine in pig houses. Biosystems Engineering, 98, 206–214.

© Woodhead Publishing Limited, 2011

3 Food safety and processed meats: globalisation and the challenges P. Wall and J. Kennedy, University College Dublin, Ireland

Abstract: Processed meat and the ingredients of processed meat are now being traded on the global stage. Consequently, contamination incidents, product recalls, litigations and adverse health effects have taken on a global dimension. Food business operators must take responsibility and can improve the safety of processed meat through sequential incremental risk reduction strategies. This chapter describes various elements of European legislation that effect the meat industry including labelling, microbiological criteria, traceability and surveillance systems as well as non-regulatory issues such as procurement policies and reformulation. Key words: safety of processed meat, EU regulatory environment, labelling, microbiological criteria, traceability, surveillance systems, procurement policies and reformulation.

3.1 Introduction Over the last number of years the global food industry has encountered numerous critical events which have impacted directly upon process controls required to ensure safe product. A chronology of outbreaks of disease and food scares in the 1990s, culminating in bovine spongiform encephalopathy (BSE), significantly damaged consumer confidence in the safety of meat and in the ability of the regulatory authorities to effectively control the food chain (Rooney et al., 2003). Meanwhile, improvements in meat processing and packaging, combined with better logistics systems as well as the use of information technology, have allowed the meat industry to confidently take advantage of increased trade liberalisation. Against this backdrop, consumer demand for ‘no-risk’ convenient value-added processed meats, globalisation of brands, geographical spread of surveillance systems, consequences of food crises, legal requirements for labelling and traceability, strict procurement policies, the use of microbial load as quality cues and

© Woodhead Publishing Limited, 2011

Food safety and processed meats: globalisation and the challenges

55

the increasing sensitivity of the analytical chemists are just some of the challenges faced by the processed meat industry. Furthermore, these challenges, along with advances in nutritional science, have caused the industry to re-evaluate how the processed meat supply chain functions and how to service the new social attributes demanded in the marketplace.

3.2 Trade liberalisation Increasing liberalisation of trade, as well as the increasing competitive commercial environment, has led to the trading of food and food ingredients on the global stage. Between 1975 and 1985 the value of global processed food trade increased by 5% per year, but grew at almost double that rate from 1985 to 1995. In 1995 processed foods accounted for 56% of the developing world’s agricultural exports, and 66% of those of developed countries (Rae and Josling, 2003). Global trade of processed meat and processed meat ingredients means longer and more complex food chains, more steps/interventions within the food chain where things can go wrong and more players in the food chain, which increases likelihood of sub-optimum practices. Indeed, Salmonella agona first spread around the world as a consequence of the use of contaminated Peruvian fish meal in chicken feed (Tauxe and Hughes, 1996) while more recently in 2005 chilli powder adulterated with the carcinogen Sudan 1 led to the biggest recall in UK history, with over 400 products removed from the shelves, and in 2008 all Irish pork products were recalled from up to 25 countries, including the United States, Russia, Japan, China, France and Germany after it was discovered that they may be contaminated with dioxin. In this global environment the consequences of a contamination incident not only can have devastating effects on public health but can also damage the reputation and brands of the food companies or industries involved. Reputations and brands that take years to build can be irreparably damaged over night by being associated with a food scare or adverse health effects. The General Agreement on Tariffs and Trade (GATT) recognises that certain exceptions to free trade can be necessary to protect higher values such as health and food safety. However, concerns about food safety, human health, animal and plant health can induce national authorities to take measures which may frustrate the free flow of trade. To address these concerns about disrupting food trade, two World Trade Organization (WTO) treaties were concluded: the Agreement on Technical Barriers to Trade (the TBT Agreement) and the Agreement on the Application of Sanitary and Phytosanitary Measures (the SPS Agreement). The SPS Agreement was drawn up to ensure that countries apply measures to protect human and animal health (sanitary measures) and plant health (phytosanitary measures) based on the assessment of risk or, in other words, based on science. The SPS Agreement incorporates, therefore, safety

© Woodhead Publishing Limited, 2011

56

Processed meats

aspects of foods in trade. The TBT Agreement covers all technical requirements and standards (applied to all commodities), such as labelling, that are not covered by the SPS Agreement. Therefore, the SPS and TBT Agreements can be seen as complementing each other. The SPS Agreement is very important from a food safety point of view. The SPS Agreement recognises and further elaborates on the right of the parties to this agreement to take sanitary and phytosanitary measures necessary for the protection of human, animal or plant life or health. The measures must be scientifically justified and they may not be discriminating, nor constitute disguised barriers to international trade. If the measures are in conformity with international standards, no scientific proof of their necessity is required. The most important international standards regarding SPS are set by the so-called three sisters of the SPS Agreement: the Codex Alimentarius Commission, the International Office of Epizootics (OIE12) and the Secretariat of the International Plant Protection Convention (IPPC). The standards on food and on food safety are mainly to be found in the Codex Alimentarius. The WTO and tariffs influence patterns of meat distribution. For example, poultry imports into the EU are presumed to grow in the longer term, following the WTO ruling against the EU duties on partly processed poultry meat (up 35.8% between 2004 and 2012). However, while the WTO SPS agreement outlines food safety requirements for Member States relating to food safety, individual trading blocks have their own additional requirements. For example the European Union, which is one of the biggest importers of food worldwide, has import rules for meat and meat products. 3.2.1 European import rules The European Commission acts as the competent authority on behalf of the Member States to ensure that there is compliance with these import rules. The European Commission is the sole negotiating partner for all non-EU countries in questions related to import conditions for processed meat. The eligibility criteria are as follows: • Exporting third countries must have a Competent Authority which is in charge of the inspection and certification of veterinary and general hygiene conditions. • The country or region of origin must fulfil the relevant Animal Health standards of the EU. • The national authorities must also guarantee that the hygiene and public health requirements are met and that a monitoring system is in place to verify compliance with the maximum permitted level of residues of veterinary medicines, pesticides and contaminants. • Imports are only authorised from approved establishments (e.g. slaughterhouses, cold stores, processing plants), for which the national authorities have submitted guarantees.

© Woodhead Publishing Limited, 2011

Food safety and processed meats: globalisation and the challenges

57

• An inspection of the European Commission’s Food and Veterinary Office is necessary to confirm compliance (http://ec.europa.eu/food/ resources/import_conditions/meat.pdf). Imports of meat or meat products must enter the EU via an approved Border Inspection Post under the authority of an official veterinarian. Each consignment is subject to a systematic documentary check, identity check and, as appropriate, a physical check which can include laboratory analysis. The frequency of physical checks depends on the risk profile of the product and also on the results of previous checks. Consignments which are found not to be compliant with Community (EU) legislation shall either be destroyed or, under certain conditions, returned to sender within 60 days. If processed meat consignments have been tested and rejected at the external borders of the EU (and the European Economic Area – EEA) and a health risk has been found, a notification is sent to all EEA border posts in order to reinforce controls and to ensure that the rejected product does not re-enter the EU through another border post (see Section 3.2.5 for details about the Rapid Alert System for Feed and Food (RASFF)). 3.2.2 Processed meat labelling and traceability Labelling of processed meat, like labelling of any other food, aims to provide consumers with key information on the properties of the meat and allows them to make informed purchase decisions. The current labelling requirements for processed meat are described on pages 58–62. The EU has undertaken to consolidate all existing legislation on labelling into the Food Information to Consumers Regulation. This proposed legislation aims to consolidate and update existing rules and to protect consumers’ interests by providing accurate, necessary information required to enable them to make informed choices about the food they purchase. However, this regulation is not expected until the end of 2011. Another regulation that is already impacting the processed meat sector is EU Regulation 1924/2006 which addresses nutrition and health claims. In the Annex to this regulation there is a list of the nutrient content claims that can be used. For example, for a food to claim that it is a ‘source of protein’ 12% (at least) of the energy value of the food must be provided by protein, and for a food to claim that it is ‘high in protein’ 20% (at least) of the energy value of the food must be provided by protein. Another example of the nutrient content claims relates to vitamins and minerals, in this case they can only be declared if they are present in the food in ‘significant amounts’. A significant amount is defined as 15% of the recommended daily allowance (RDA). For the purposes of nutrition labelling, the RDAs in the Annex to directive 90/496/EEC, as amended, must be used. Furthermore, restrictions on the addition of vitamins and minerals as set out in Article 4 of Regulation (EC) No. 1925/2006 states that vitamins and minerals may not be added to unprocessed foodstuffs, including, but not limited

© Woodhead Publishing Limited, 2011

58

Processed meats

to, fruit, vegetables, meat, poultry and fish; therefore processed meat would have to be enriched via animal feed. Council Directive 2000/13/EC Council Directive 2000/13/EC on the approximation of the laws of the Member States relating to the labelling, presentation and advertising of foodstuffs given detailed labelling informing consumers as to the exact nature and characteristics of the foodstuff. In addition to the general requirements for food labelling, pre-packed processed meat labels must contain the name under which the product is sold list of ingredients and declaration of allergens, quantity of certain ingredients, net quantity, date of minimum durability (use by date), any special storage instructions or conditions of use, name or business name and address of the manufacturer or packager, or of a seller within the European Union, place of origin of the foodstuff if its absence might mislead the consumer (see section on country of origin labelling) and instructions for use where necessary. Furthermore, the name of the foodstuff, the date of minimum durability and the net quantity must appear on the label in the same field of vision. Products such as ready meals and sausages must declare the animal species from which the meat is derived, such as ‘bovine meat’ or ‘beef meat’ or simply ‘beef’ in the list of ingredients. The meat content must, in addition, comply with the definition as set out in Commission Directive 2001/101/ EC. In addition, additives performing technological functions in the final food must be declared in the list of ingredients such that the name of the category of additive is followed by the specific name of the additive or its E number, e.g. sulphur dioxide, a preservative commonly used in sausages must be declared in the list of ingredients as: ‘Preservative: Sulphur Dioxide’ or ‘Preservative: E220’. Commission Directive 2001/101/EC Commission Directive 2001/101/EC as amended by Commission Directive 2002/86/EC on the definition of meat Directive 64/433/EEC on health problems affecting intra-Community trade in fresh meat to extend it to the production and marketing of fresh meat (consolidated by Directive 91/497/ EEC and amended by Directive 95/23/EC) resulted from the amendment of Directive 2000/13/EC on the labelling, presentation and advertising of foodstuffs by Commission Directive 2001/101/EC to tighten up the definition of ‘meat’ for the labelling of meat-based products such as pies, pasties, cooked meat, prepared dishes and canned meat. Firstly, the legislation restricts the definition of ‘meat’ to the skeletal attached muscles only. Therefore any parts of the animal for human consumption other than skeletal attached muscles such as heart, liver, kidney, tongue or even fat must now be declared separately in the list of ingredients. Secondly, the species from which the meat came must also be declared. If the species name is being

© Woodhead Publishing Limited, 2011

Food safety and processed meats: globalisation and the challenges

59

used, such as poultry, porcine, ovine, the name must be followed by the word ‘meat’ e.g. Poultry meat. However, if the generic name is being used on the product label such as chicken, pork, lamb, then the word ‘meat’ can be omitted. The legislation applies only to packaged products which contain meat as an ingredient. This legislation is not applicable to meat which is sold without further processing, such as steaks, chops and cutlets or to anatomical parts such as ribs, chicken wings and chicken legs. The legislation does not apply to cuts of meat and anatomical parts which are processed but in which the anatomical structure is still recognizable, e.g. Cooked Roast Chicken Breast. Council Directive 94/65/EC Council Directive 94/65/EC of 14 December 1994 laying down the requirements for the production and placing on the market of minced meat and meat preparations Council Directive 77/99/EEC (OJ L26, p85, 31/01/1977) of 21 December 1976 on health problems affecting intra-Community trade in meat products of 21 December 1976 details additional marking, labelling, wrapping and packaging requirements for meat preparations including the declaration of the species from which the meat was obtained in certain circumstances, the percentage meat from each species where the meat is obtained from a mixture of species and the date of preparation. Beef labelling European Parliament and Council Regulations 1760/2000 and Commission Regulation No. 1825/20001 lay down the requirements for the labelling of fresh, frozen and minced beef. The European Communities (Labelling of Beef and Beef Products) Regulations, 2000 require a mandatory traceability and origin labelling for beef from slaughterhouse to point of sale to consumers. This labelling system for beef consists of two elements, a compulsory beef labelling system and a voluntary beef labelling system, with the objective of providing maximum transparency during the marketing of beef. Compulsory beef labelling requires operators or organisations to label beef with specific information at all stages of marketing. The requirements apply to all fresh or frozen beef, either carcasses, de-boned meat, cut meat or minced meat, which are marketed in the EU. The information required under the Labelling of Beef Regulations should be applied to or attached to individual pieces of meat or to their packaging material. Where beef is not wrapped, the information is required to be provided in a written and visible form to the consumer at point of sale. Table 3.1 summarises the labelling requirements for beef. Draft Regulation on Information to Consumers (COM (2008) 40) A new Draft Regulation on Information to Consumers is currently being debated in Europe (COM (2008) 40) and is attempting to leave the basic country-of-origin requirements as they currently are, stating that the

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

• = indicate on board/tray, etc. • = indicate on label. • = may be indicated.

Reference/traceability code or number Approval number of slaughter house Member State/country of the slaughter house Approval number of cutting hall Member State/country of the cutting hall ‘Origin: name of country’ ‘Born in ... name of country’ ‘Reared in ... name of country’ ‘Slaughtered in ... name of country’ ‘Prepared in ... name of country’ Date on which meat was prepared

• • • • • •

Beef sold unpacked

• • •

• • • • •

Un-packed from animals from different Member States/countries • • • • • •

Pre-packed/ packed in-store

• • •

• • • • •

Pre-packed from animals from different Member States/countries

• • •

• • • • • •

Minced beef

Table 3.1 Summary of Requirements for Compulsory Beef Labelling, taken from Food Safety Authority of Ireland’s Guidance Note No. 17 on The Labelling of Meat

Food safety and processed meats: globalisation and the challenges

61

indication of the country of origin or of the place of provenance of a food should be provided whenever its absence is likely to mislead consumers. Labelling of Restructured Meat Products Binding of meat cuts and trimmings can be achieved using a variety of substances which allow manufacturers to produce portion-controlled standardised meat products with uniform shape, thickness and quality, using smaller pieces/cuts of meat. One of the most common binding agents is transglutaminase, a naturally occurring enzyme which is widely present in nature. The enzyme is also used in restructuring meat products such as sausages, hot dogs and restructured steaks. Transglutaminase is considered a processing aid in the current EU legislation on food enzymes, Regulation (EC) No 1332/2008, and as it has no function in the final product it does not need to be mentioned on the product label. Another binding agent is a thrombin/fibrinogen preparation but in May 2010, the European Parliament blocked the authorisation of this preparation as an additive due to the potential for the use of the product to mislead consumers – as a result it cannot be used within the EU. However, this decision did not affect the use of other binding agents. Alginate (E401) and carrageenan (E407) are approved food additives (binding agents) and any product in which they are used to bind meat are required to be labelled in line with existing labelling requirements. Starches used to bind meats are considered to be food ingredients and as such must be mentioned in the ingredients list of any product in which they are used for this purpose. However, the restructured meat products manufactured using the processing aids will themselves need to be labelled in line with the general labelling rules and in particular Directive 2001/101/EC, which requires that the meat content and species is declared in a product containing meat as an ingredient. Other specific labelling may also be required depending on the substance used to bring about the binding. Traceability – EC Regulation 178/2002 EC Regulation 178/2002 lays down the general principles and requirements of food law, establishing the European Food Safety Authority and laying down procedures in matters of food safety. Among other things, this Regulation defines traceability as the ability to trace and follow food, feed and ingredients through all stages of production, processing and distribution. The Regulation contains general provisions for traceability (applicable from 1 January 2005) which cover all food and feed, all food and feed business operators, without prejudice to existing legislation on specific sectors such as beef, genetically modified organisms (GMOs), etc. Importers are similarly affected as they are required to identify from whom the product was exported in the country of origin. Unless specific provisions for further traceability exist, the requirement for traceability is limited to ensuring that businesses are at least able to identify the immediate

© Woodhead Publishing Limited, 2011

62

Processed meats

supplier of the product in question and the immediate subsequent recipient, with the exemption of retailers to final consumers (one step back, one step forward). With regard to traceability, the identification of the origin of feed and food is of prime importance for the protection of consumers, for labelling purposes but particularly when products are found to be faulty. Despite the best efforts of the WTO SPS Agreement, not all processors have the same high standards and not all countries have the same controls or enforcement capabilities. Traceability is a legal requirement in many jurisdictions, it facilitates the withdrawal of foods and enables consumers to be provided with targeted and accurate information concerning implicated products. This is of particular importance because, as mentioned previously, the modern food chain is now more like a maze than a straight line. At the level of primary production of livestock agrochemicals, animal feed, minerals and other feed additives, veterinary drugs, etc. are all sourced on the global stage. At the processing stage many foods contain multiple ingredients and co-mingling of products from several processors, often from different jurisdictions, is increasingly commonplace. To comply with traceability legislation it is not necessary in law to trace to the batch level. Traceability is not a guarantee of safety but is an essential component of every food safety management system. Consumer demand for country-of-origin labelling further emphasises the need for traceability systems.

3.2.3 Logistical challenges of transporting processed meat The logistical challenges of transporting processed meat safely across continents have led to huge advances in packaging technology. In the United States, Japan and Australia, active and intelligent packaging is already being successfully applied to extend shelf-life while maintaining nutritional quality and microbiological safety. Examples of commercial applications include the use of oxygen scavengers for sliced processed meat and the use of moisture absorbers for fresh meat and poultry. Other examples include datapacks (temperature data loggers which are placed in containers in order to track the temperature control of containers during transit) as well as radio frequency identification (RFID) tags which can be fitted to containers/pallets and tracked globally (i.e. containers can be tracked ensuring complete traceability). In Europe, however, only a few of these systems have been developed and applied. The main reasons for this are legislative restrictions and a lack of knowledge about their acceptability to European consumers. Regulation 450/2009 lays out an authorisation process for the use of new active or intelligent substances in food contact materials. The legislation foresees that manufacturers requesting such an authorisation must first submit an application for the assessment of the safety of the relevant substance(s) to the European Food Safety Authority (EFSA). According to EFSA’s Guidelines,

© Woodhead Publishing Limited, 2011

Food safety and processed meats: globalisation and the challenges

63

this assessment will focus on three inter-related matters that include the migration of active or intelligent substances; the migration of their degradation and/or reaction products; and toxicological properties of the substances, per se, and their degradation or by-products. Innovations have the potential to improve the safety of processed meats and the applications of bacteriophages in the processing environment and in the final product, and advances in nanotechnology are likely to make a contribution in the coming years if the issue of consumer acceptability is satisfactorily addressed.

3.2.4 The use of microbial load as quality cues Raw meat is not a sterile product and pathogens, such as Salmonella in poultry meat and E. coli in beef will be found routinely. A company that does not find occasional positives should question its sampling and testing procedures. Historically, in most companies, alarm bells only began to ring when pathogens appeared in the high risk areas of the plant or close to or in finished product. However, it is important to monitor the low risk side of the plant also as pathogens can build up and even colonise the low risk side increasing the challenge on the critical control points such as cooking or fermenting. Environmental monitoring can alert a food business operator to the presence of pathogens in the plant before final product becomes contaminated. Biofilms can facilitate the survival of pathogens including listeria and make cleaning regimens ineffective. Swabs in the outlet drains for the duration of a shift can often give a better picture of the microbial profile of the area than intermittent contact swabs or random sampling of finished product. Periodic verification of cleaning regimens using marker organisms can help ensure that the cleaning chemicals and routine cleaning protocols are performing as intended. The microbiological quality of processed meat in the EU is mainly ensured by a preventive approach, such as implementation of good hygiene practices and application of procedures based on hazard analysis and critical control point (HACCP) principles. Regulation (EC) 2073/2005 contains microbiological criteria for meat products/microorganism combinations, above which a foodstuff should be considered unacceptably contaminated with the microorganisms for which the criteria are set. Testing against the criteria in the legislation should be undertaken when validating or verifying the correct functioning of the control systems in place. In addition food business operators (FBOs) should determine shelf-life by a strict testing programme to ensure that the criteria are met over the entire intended shelf-life of the product. The Annex to Regulation (EC) 2073/2005 contains criteria for: (a) minced meat and meat preparations intended to be eaten raw, (b) minced meat and meat preparations made from poultry meat intended to be eaten cooked, (c) minced meat and meat preparations made from other species than poultry intended to be eaten cooked, (d) meat products intended to

© Woodhead Publishing Limited, 2011

64

Processed meats

be eaten raw, excluding products where the manufacturing process or the composition of the product will eliminate the salmonella risk, and (e) meat products made from poultry meat intended to be eaten cooked. For example, in all cases (a–e), from 1 January 2010 there should be no Salmonella in 25 g of sample tested over the duration of a product’s shelf-life. Article 4 of Regulation (EC) No 852/2004 places an obligation on FBOs to comply with microbiological criteria for foodstuffs. The producer or manufacturer of a food product has to decide whether the product is ready to be consumed as such, without the need to cook or otherwise process it in order to ensure its safety and compliance with the microbiological criteria. According to Article 3 of Directive 2000/13/EC relating to the labelling, presentation and advertising of foodstuffs (described on pages 58–62), the instructions for use of a foodstuff are compulsory on the labelling when it would be impossible to make appropriate use of the foodstuff in the absence of such instructions. Such instructions should be taken into account by food business operators when deciding appropriate sampling frequencies for the testing against microbiological criteria.

3.2.5 Surveillance systems Improvements are continually being made in surveillance systems, both passive and active, in order to monitor trends, establish public health priorities, detect and delineate outbreaks, identify emerging pathogens and monitor interventions. Because of the distribution of products and the increasing movement of people, initiatives are underway to standardise surveillance systems, laboratory methods and protocols within and between countries in order to ensure uniform public health protection. Many of the foodborne pathogens are zoonotic agents so the health of consumers is inextricably linked to the health of food producing animals. With the increasing ability to identify microbes at the molecular level and the use of molecular epidemiology to resolve outbreaks of disease there are increasing efforts to standardise typing techniques and protocols. This is permitting the comparison of data from animal feed, livestock, human food and sick people and is enabling the tracking of pathogens back through the food chain, often across continents, to the source of the problem where the corrective action is needed. Companies inadvertently or deliberately putting contaminated product on the market are likely to be identified by the new breed of foodborne disease epidemiologists and ‘forensic microbiologists’ who are collaborating internationally and now see themselves in the role of disease detectives. Major meat manufacturing companies should be using the latest molecular methods for rapid diagnostics and definitive typing of microbes to protect their customers’ health, their brand names and for due diligence defence in the event of something going wrong. The major players should have all pathogens identified and definitively typed so that they can be aware of whether a contamination is a new

© Woodhead Publishing Limited, 2011

Food safety and processed meats: globalisation and the challenges

65

incident or a re-occurring one, whether there is a focus of contamination in their facility or whether particular clones are associated with particular suppliers of raw ingredients. Maintaining a database of identified pathogens may also prove useful if a company is wrongly accused in an outbreak situation. Some of the major surveillance systems include Enter-net, an international surveillance network for Salmonella and Vero-toxigenic E. coli O157 infections (Health Protection Agency), Med-Vet-Net which is a European network of veterinary and public health institutes which each have a national reference laboratory (Veterinary Laboratories Agency) and PulseNet which is a network of US state health departments, local health departments and federal agencies (Centers for Disease Control and Prevention). There are increasing numbers of examples of the usefulness of these systems in standardising typing techniques and preventing the further spread of infectious agents such as a Salmonella Typhimurium DT104 outbreak which occurred in Denmark in 2005. This outbreak was traced to a single restaurant. Comparisons by Multi-locus Variable number of tandem repeat Analysis (MLVA) typing of patient strains with strains from the food surveillance system identified that the source of the outbreak was imported carpaccio (beef). An Enter-net Urgent Inquiry was issued and a total of seven countries responded to the Enter-net inquiry (Kivi et al., 2007). In the United States in 1998 pulsed field gel electrophoresis (PFGE) typing carried out by PulseNet laboratories showed that several case isolates from different states had indistinguishable DNA fingerprints. On further investigation, 101 Listeria infections with bacteria having the same or highly similar DNA fingerprints were identified in 22 states. Fifteen deaths and six miscarriages or stillbirths were reported among patients who were infected with the outbreak strain. This outbreak was traced to contaminated hot dogs and sandwich meat produced at a single large meat-processing plant in Michigan. After the company voluntarily recalled the implicated lots of product and suspended production, the outbreak ended (Swaminathan et al., 2001). In Europe the Rapid Alert System for Feed and Food (RASFF) with its legal basis in Regulation (EC) No. 178/2002 is in place with the purpose of providing the national food safety authorities throughout the EU, and further afield, with an effective alert tool for exchange of information on measures taken to ensure food safety. Traceability allows the RASFF to operate effectively and allows food business operators or authorities to withdraw or recall products which have been identified as unsafe because they have the ability to track any food, feed, food-producing animal or substance that will be used for consumption, through all stages of production, processing and distribution. The system is made up of contact points in all RASFF member countries, member organisations and in the European Commission, which exchange information of any health risk. There is a round-the-clock service to ensure that urgent notifications are

© Woodhead Publishing Limited, 2011

66

Processed meats

sent, received and responded to in the shortest time possible. When a RASFF member country has any information about a serious health risk from food or feed, it must inform the European Commission using the RASFF system. The European Commission then immediately informs the other members in order to take the appropriate actions. All incoming information is assessed by the Commission and forwarded to all RASFF members using one of the four types of notification. 1. Alert notifications are sent when food or feed presenting a serious risk is available on the market and when rapid action is required such as a recall or withdrawal. 2. Information notifications are used in the same situation, but when the other members do not have to take rapid action because the product is not on the market or the risk is not considered to be serious. 3. Border rejections concern food and feed consignments that have been tested and rejected at the external borders of the EU (and the EEA) when a health risk has been detected. 4. Any information related to the safety of food and feed products which has not been communicated as an alert or an information notification, but which is judged valuable for the control authorities, is transmitted to the members under the heading ‘News’. Similar electronic alert mechanisms exist in other jurisdictions. The European Commission has taken many initiatives over the past few years, using its ‘Better Training for Safer Food’ programme, to share its knowledge and experience with developing countries. In 2007, 2008 and 2009 there were 121, 126 and 138 RASFF alerts related to meat and meat products (other than poultry), respectively. These RASFFs originated from over 40 countries across the EU and beyond (see Fig. 3.1). In the first six months of 2010, there was 36 RASFFs relating to meat and meat products. These RASFFs were issued due to a variety of reasons including the presence of Salmonella Typhimurium, the presence of Listeria monocytogenes, incomplete/incorrect certification and incorrect temperature control. There were also 16 RASFFs issued for poultry and poultry products in the first 6 months of 2010, and the majority of these RASFFs were related to the presence of Salmonella.

3.2.6 Procurement policies No food business can afford to be complacent as it is only as secure as the standards of the weakest supplier from whom it accesses raw material, ingredients or products. Increasingly the supermarket multiples and commercial caterers include rigid food safety requirements in their product specifications and failure to comply can result in immediate delisting as an approved supplier. The risk and consequences of contamination incidents are very different for the array of stakeholders along the food chain from

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Number of RASFFs

Fig. 3.1

Incidence and origin of rapid alerts in 2007, 2008 and 2009.

y ly a in e s m d rk m a il d ia ic a ia d ia ia ia m y pt s ia n ia o d n al ia d s ta le n of ia ia y s an Ita hin pa anc and giu lan ma do ntin raz lan str ubl nad gar rlan an ak tral tna gua gy pru ab atio ys xic lan ano tug es lan tate al Chi ista lic oat ib rke ine m k b r a m T u ip p C S Fr erl el Po n ing ge B Ire Au ep a ul ze om lov us ie ru E Cy lb er ala Me ea b or on Fin S M e er A d M z Le P nd il Pa epu C N h B R C B wit R S A V U D K Ar G ed I fe w t et h i d Ph R e S c n n e N t N a ic U ze ni si m C U la us s R I n, Ira 2007 2008 2009

0

5

10

15

20

25

30

68

Processed meats

artisan and local producers to global players in the processing, retail and food service sectors. As well as demands to comply with the basic legal requirements, retailers procurement policies include more comprehensive traceability requirements to enable more limited, and targeted recalls in the advent of a contamination incident. If the legal food safety requirements are akin to the pass level of the exam, a diligent company using third party quality assured suppliers is in the honours class. Even in the best run systems things can go wrong so an early warning and response system is also essential. The repercussions of FBOs not managing the risks can be immense in terms of consumer health, product recalls and litigation costs. E. coli O157:H7 was only first recognised as a human pathogen in 1982 during an outbreak of illness caused by hamburgers from a fast food restaurant in Oregon. But the problem drew little public attention until 10 years later when 600 people across the western United States became ill after eating undercooked Jack in the Box hamburgers. Four children died, and many others suffered from kidney damage. Jack in the Box, co-defendants and insurers paid out over $125 million in compensation to victims. The costs to the businesses involved were at least twice that (Marler, 2007). FBOs need not only to manage their business but also to manage their risks.

3.3 Safety of processed meat from a nutritional point of view Meat is, and was originally, processed to preserve it, but since the various procedures cause so many changes in texture and flavour it is also a means of adding variety to the diet in a convenient way. However, it has been estimated that about 65–70% of total dietary sodium intake is from manufactured foods and two food groups, meat/fish (mainly processed meat) and bread, account for over 50% of sodium intake from foods (FSAI, 2005). There is a direct, causal link between dietary salt intake and raised blood pressure. Some studies have also demonstrated an association between the consumption of processed meat and colorectal cancer risks (Bender, 1998). A similar conclusion was reported by the Colon Cancer Panel at the World Health Organization consensus conference (Scheppach et al., 1999) and the Working Group on Diet and Cancer of the Committee on Medical Aspects of Food and Nutrition Policy in 1998 (Chan, 2000). In more recent meta-analyses of colorectal cancer that included studies published up to 2005 (Larsson and Wolk, 2006; Norat et al., 2002; Sandhu et al., 2001; Chao et al., 2005), summary associations indicated that processed meats were associated with elevated risks of 20–49%. However, the aetiology of cancer is complex and exposure to a range of risk factors, and also

© Woodhead Publishing Limited, 2011

Food safety and processed meats: globalisation and the challenges

69

protective factors, and the individual’s genetic susceptibility all influence the incidence. For nearly 30 years, the omission of nitrate/nitrite (which is used for colour development, flavour and micro-biological safety) from meat processing has been proposed (Mirvish et al., 2002) and effectively applied (Skjelkvale et al., 2006). It is now known that acceptable alternatives for the use of nitrate and nitrite exist (for example a purified red haem pigment for use in cooked meat products; Pegg and Shahidi, 2004). Useful, and EU accepted, colouring additives are also available as well as alternatives including Zn-porphyrin which is the red substance formed in products such as Parma ham, in the absence of nitrite. Meat products of acceptable hygienic and sensory quality using vegetable juices as sources of nitrates and nitrites were recently developed in the United States. Processed meat is convenient and relatively cheap for consumers and a healthy diet is all about balance moderation and portion control. The food safety regulations, procurement policies and surveillance systems discussed above address the food safety risks. From a nutritional point of view the move to reduce nitrates, nitrites and salt from processed meat to diminish any possible risk of chronic illnesses associated with processed meat should proceed cautiously to ensure that the survival of microbes, including Clostridium botulinum, is not facilitated.

3.4 Conclusions Increasing liberalisation of trade and increasing competition in the international marketplace means that processed meat and ingredients are being traded on the global stage affording the opportunity for pathogens to be disseminated widely. Food safety along the food chain can be improved through sequential incremental risk reduction strategies. There is no such thing as zero risk and sporadic food crises are inevitable. While pathogenspecific control programmes are required and more research and surveillance needed to understand the epidemiology of the different agents, simply increasing hygiene standards across the food chain will have the effect of reducing all foodborne disease. The consequences of contamination incidents, product recalls, costly litigation and adverse health effects associated with product means that food safety must be a top priority for all food companies no matter what their size. Without doubt, when a crisis occurs, regulators will be quick to stress the legal position, which is that the feed and food operators carry the responsibility to produce safe feed and food. The onus is on the processed meat sector to constantly look at their procedures and practices to ensure that everything that can be done is being done to reduce the risk of contamination. A better informed public, and unforgiving media, will expect companies to have taken all reasonable steps to reduce the possibility of contamination occurring. If new scientific

© Woodhead Publishing Limited, 2011

70

Processed meats

approaches are available and safe, companies will be expected to have adopted them in the protection of public health and the environment. Furthermore, for the processed meat sector to thrive it is likely that reformulation will have to become a key point on the research agenda to address the health concerns of consumers.

3.5 References and further reading bender, a. (1998). ‘Food nutrition and the prevention of cancer: a global perspective.’ Food Science and Technology Today 12: 25–28. bureau, j., s. marette, et al. (1998). ‘Non-tariff trade barriers and consumers’ information: the case of the EU–US trade dispute over beef.’ European Review of Agricultural Economics 25(4): 437. chan, w. (2000). ‘Nutritional aspects of the development of cancer.’ Nutrition and Food Science 30(4/5): 174–177. chao, a., m. thun, et al. (2005). ‘Meat consumption and risk of colorectal cancer.’ JAMA 293(2): 172. fsai (2005). FSAINews ‘radical reduction in salt required.’ Food Safety Authority of Ireland. kivi, m., a. hofhuis, et al. (2007). ‘A beef-associated outbreak of Salmonella Typhimurium DT104 in The Netherlands with implications for national and international policy.’ Epidemiology and Infection 135(06): 890–899. larsson, s. and a. wolk (2006). ‘Meat consumption and risk of colorectal cancer: a meta-analysis of prospective studies.’ International Journal of Cancer 119(11): 2657–2664. marler, w. (2007) ‘Food safety and the CEO – keys to bottom line success.’ Food Safety Magazine, Oct/Nov. The Target Group. Available at: www.foodsafety magazine.com mirvish, s., j. haorah, et al. (2002). ‘Total N-nitroso compounds and their precursors in hot dogs and in the gastrointestinal tract and feces of rats and mice: possible etiologic agents for colon cancer.’ Journal of Nutrition 132(11): 3526S. norat, t., a. lukanova, et al. (2002). ‘Meat consumption and colorectal cancer risk: dose-response meta-analysis of epidemiological studies.’ International Journal of Cancer 98(2): 241–256. pegg, r. and f. shahidi (2004). Nitrite Curing of Meat: The N-nitrosamine problem and nitrite alternatives, Wiley-Blackwell. rae, a. and t. josling (2003). ‘Processed food trade and developing countries: protection and trade liberalization.’ Food Policy 28(2): 147–166. regmi, a., m. gehlhar, et al. (2005). ‘Market Access for High-Value Foods.’ Agriculture Economic Report No. 840. Department of Agriculture (USDA), United States. riboli, e., k. hunt, et al. (2007). ‘European Prospective Investigation into Cancer and Nutrition (EPIC): study populations and data collection.’ Public Health Nutrition 5(6b): 1113–1124. rooney, r., p. g. wall, et al. (2003). ‘Food safety.’ In Encyclopedia of Food Sciences and Nutrition. Oxford, Academic Press: 2682–2688. sandhu, m., i. white, et al. (2001). ‘Systematic review of the prospective cohort studies on meat consumption and colorectal cancer risk.’ Cancer Epidemiology Biomarkers & Prevention 10(5): 439. scheppach, w., s. bingham, et al. (1999). ‘WHO Consensus statement on the role of nutrition in colorectal cancer.’ European Journal of Cancer Prevention 8(1): 57.

© Woodhead Publishing Limited, 2011

Food safety and processed meats: globalisation and the challenges

71

skjelkvåle, r., t. tjaberg, et al. (2006). ‘Comparison of salami sausage produced with and without addition of sodium nitrite and sodium nitrate.’ Journal of Food Science 39(3): 520–524. swaminathan, b., t. barrett, et al. (2001). ‘PulseNet: the molecular subtyping network for foodborne bacterial disease surveillance, United States.’ Emerging Infectious Diseases 7(3): 382. tauxe, r. and j. hughes (1996). ‘International investigation of outbreaks of foodborne disease.’ British Medical Journal 313(7065): 1093.

© Woodhead Publishing Limited, 2011

4 Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli: significance and contamination in processed meats C. C. Adley and C. Dillon, University of Limerick, Ireland

Abstract: Processed meat is a main source and route of infection by foodborne pathogens. The control of hygiene from farm to fork cannot be emphasised enough either by legislation or by continuous educating and training. Monitoring and sampling are of paramount importance for complete food chain control and management and in particular a reliable cold chain recording system under legislative control is necessary. Many worldwide standard food operation guidelines are in place to ensure food standards. In spite of this there are still increased incidences of infection due to select microorganisms. Climate changes may alter the pathogen profile in some areas. The changes in farm stocking densities have led to the emergence of Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis), a respiratory animal pathogen. Food processing increases the probability of foodborne illnesses due to increased opportunity of the organism to spread and sequester in the processed food matrix. This chapter will review the significant number of select organisms that cause disease in meat processed foods. The importance of the ability of many microbes to form viable but non-culturable forms will be discussed. Key words: microbial pathogens, processed meat, Listeria monocytogenes, Escherichia coli, Salmonellosis.

4.1 Introduction In Europe the main types of meat produced are poultry, pork and bovine. Meat and meat products act as an ideal growth medium for microbial pathogens that pose a risk to human health (Mataragas et al., 2008) and have been linked as the vehicle for many foodborne disease outbreaks throughout the world. Meat safety is therefore of real concern to public health officials.

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

73

International Food Standard guidelines are developed by the Codex Alimentarius Commission (CAC) (http://www.codexalimentarius.net) and the CAC/GL 21-1997 (Codex, 1997) guideline deals with microbiological criteria for food. The CAC was established by the Food and Agriculture Organization (FAO) of the United Nations (UN) and the World Health Organization (WHO) in 1963. The European Union (EU) requires that food products should not contain microbial loads at levels that pose a risk to human health. Requirements are laid down in Commission Regulation 2073/2005 (EC, 2005a). The food industry is highly regulated in developed countries, some under legislative control, with hazard analysis and critical control point (HACCP) based strategies and legislation in place for the examination of specific processes within a product line. The introduction of such strategies along with advances in refrigeration, hygiene, food packaging, training and education has resulted in significant improvements in the safety of meat products. Despite these advances, however, cases and outbreaks of foodborne disease due to contaminated meat products remain a real concern in both developed and developing countries. International and national surveillance networks are in place to monitor select foodborne pathogens (AmatoGauci and Ammom, 2008; Molnar et al., 2006). Surveillance networks include FoodNet within the Centers for Disease Control and Prevention (CDC) in the United States (http://www.cdc.gov/FoodNet/); OzFoodNet in Australia (http://www.ozfoodnet.org.au/) and the newly established European Centre for Disease Prevention and Control (ECDC) in Stockholm (www.ecdc.europa.eu). The Health Protection Surveillance Centre (HPSC, www.hpsc.ie) is Ireland’s specialist agency for the surveillance of communicable diseases. The HPSC together with the Food Safety Authority of Ireland (FSAI www.fsai.ie) carry out monitoring. This chapter will review three significant culprits in foodborne diseases, Listeria monocytogenes, Escherichia coli and Salmonella spp., in relation to processed meat. The emergence of new serotypes along with antibiotic resistance is a real concern to public health officials.

4.2

Listeria monocytogenes

Listeria is divided into eight species of which L. monocytogenes is the most significant species. L. monocytogenes was first identified in rabbits in 1924 (Murray et al., 1926). L. monocytogenes is haemolytic, Gram positive, oxidase negative and catalase positive, motile at 20–28 °C with one to five peritrichous flagella (Allerberger, 2003). Listeriosis caused by L. monocytogenes is a rare cause of human disease; however, infection in pregnant women, elderly and immunocompromised individuals can have severe consequences. The USA FDA, Food Service Inspection Services (FSIS), report the consumption of non-reheated, ready-to-eat (RTE) deli meat

© Woodhead Publishing Limited, 2011

74

Processed meats

and poultry products as the largest risk of developing listeriosis (FSIS, 2002a). Listeria is ubiquitous in both agricultural environments and food processing plants. It is the most important foodborne pathogen in RTE meats given its ability to survive and multiply under cold storage temperature ranges of 0–45 °C; its ability to grow in vacuum and gas packed products; along with its ability to contaminate food after processing. Cross-contamination can occur post-thermal treatment, if equipment used to handle and package the product are contaminated. Cross-contamination is due mainly to poor facility design (Beresford et al., 2001; FSIS, 2002a, 2003; Glass and Doyle, 1989; Sofos, 2008; Tompkin, 2002). Growth of Listeria has been recorded in the presence of oxygen or without (it grows optimally under microaerophilic conditions), at pH values between 4.5 and 9.2 (it grows optimally on meat at or above pH6 and grows poorly at pH below 5) (Glass and Doyle, 1989), at water activity (Aw) above 0.92 and in high salt values of 10–20% (Duché et al., 2002; Nørrung, 2000). Listeria can survive high temperatures during in-package pasteurisation if the temperature is increased slowly or if the pathogen has been exposed to temperatures above 42 °C prior to heat treatment (Rowan and Anderson, 1998). McCormick et al. (2003) demonstrated a temperature of 85 °C for 10 seconds is sufficient to destroy all L. monocytogenes cells present in a RTE turkey product during in-package heat treatment, but cells survived at lower temperature of 61 °C for 10 minutes. The infective dose is thought to be high as individuals are often exposed to low numbers, i.e. less than 100 colony forming units (cfu)/g, in foods without becoming ill (Nørrung, 2000; Nørrung et al., 1999). The infective dose varies in accordance with the immunological standing of the host but is believed to be 102–109 cfu (Jemmi and Stephan, 2006). The incubation period for L. monocytogenes is generally 1 day to 6 weeks, making it difficult to identify a specific food group responsible for an outbreak. Listeriosis has been a notifiable disease in Australia and Italy since 1993; Finland 1995, France 1999; USA 2000, Germany 2001 and Ireland since 2004. Symptoms in healthy people are usually non-invasive and include fever, vomiting and diarrhoea. In pregnant woman infection is very serious: what appear as mild flu-like symptoms in the mother can result in spontaneous abortion, premature birth, stillbirth and neonatal illness and death (FSIS, 2003). In general, fatality rates range from 20 to 30% with high hospitalisation rates. Infection can lead to complications such as septicaemia, meningitis and central nervous system infections (Gillespie et al., 2006; Nørrung, 2000). L. monocytogenes infection in immunocompromised individuals, together with the elderly and very young is extremely serious with fatality as high as 75% (Gellin and Broome, 1989). L. monocytogenes strains are serotyped according to variation in the somatic (O) and flagellar (H) antigens, more than 14 serotypes of L. monocytogenes have been described with three serotypes 1/2a, 1/2b and 4b,

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

75

causing the vast majority of clinical cases. Serotype 1/2 is the most frequently isolated from food (Borucki and Call, 2003; Gillespie et al., 2006). In recent years a change in serotype has been observed in many countries including: Finland (Lukinmaa et al., 2003); Italy (Gianfranceschi et al., 2007); the United Kingdom (McLauchlin and Newton, 1995) and Switzerland (Pak et al., 2002), with an increase in 1/2a and 1/2b and a decrease in 4b (Lukinmaa et al., 2003; Lundén et al., 2004).

4.2.1 Routes of contamination and regulations for control Meat arriving in the processing plant contaminated with Listeria is common. Heat treatment is effective in killing this pathogen, so contamination of RTE meat products is believed to occur post-processing at any stage including; manufacture, retail or domestic environments. The ability of L. monocytogenes to survive antimicrobial decontamination treatments in processing and manufacturing plants has been demonstrated (Norwood and Gilmour, 2000). Numerous studies (Berrang et al., 2002; Lundén et al., 2003; Peccio et al., 2003; Pritchard et al., 1995) have recovered Listeria isolates from equipment in processing plants and highlight for adequate hygiene practices to be implemented and followed by staff. For consumer activity Samelis and Metaxopoulos (1999) emphasised the need of heating meat products to adequate core temperatures to inactivate Listeria. It is important to store RTE meat products at the recommended temperatures as it has been shown that L. monocytogenes can multiply rapidly at 7 °C or above under aerobic conditions at typical consumer storage conditions (Lianoua et al., 2007; Pal et al., 2008). The shelf-life of RTE products under various conditions was studied by Pal et al. (2008), who found that without the addition of antimicrobials, growth rate increased by a factor of 10 when the temperature increased from 4 to 8 °C. The addition of a 2.0% potassium lactate and a 0.2% sodium diacetate formula was effective in hampering growth at 4 °C but significant growth occurred at 8 and 12 °C. The study also showed that even in the presence of antimicrobials L. monocytogenes multiplied 100 times in the normal shelf-life recommended for RTE products at 8 and 12 °C (Pal et al., 2008). EU regulations are in place to ensure the levels of L. monocytogenes in RTE foods do not increase beyond 100 cfu/g of food throughout the entire shelf-life of the product (EC, 2005a). Countries differ in the level of L. monocytogenes tolerated in foods. In Denmark zero tolerance is required in 25 g of RTE foods which have been heat treated in final packaging as well as preserved non-heat treated food, which are known to support growth of L. monocytogenes (Nørrung et al., 1999). Zero tolerance is also enforced in Switzerland, Austria, Italy, New Zealand and South Korea (Becker et al., 2005). The USA has a zero tolerance of L. monocytogenes in 25 g of cooked RTE food (Shank et al., 1996). Enforcement of the legislation is required.

© Woodhead Publishing Limited, 2011

76

Processed meats

4.2.2 Incidences of L. monocytogenes in processed meats The incidence of L. monocytogenes in the EU stands at 2–10 cases per million people. In 2006, it was the fifth most common zoonotic infection in the EU, with an incidence of 0.3 cases per 100,000 population, Denmark, Finland and Luxembourg reporting the highest incidences (EFSA, 2007, p134). In Ireland cases of listeriosis are rare, 13 cases were reported in 2008, 2 of which were pregnant woman (HPSC, 2009). The incidence of L. monocytogenes is increasing with an increase of 8.6% from 2005 to 2006 in the EU (Denny and McLoughlin, 2008; de Valk et al., 2005; EFSA, 2007, p134). The incidence in Germany has increased from 0.26 per 100,000 in 2001 to 0.62 per 100,000 in 2005 (Koch and Stark, 2006). In the UK the average number of cases per year in the period of 1990 to 2000 was 109 compared with 185 cases per year between 2001 and 2006 (Gillespie et al., 2006; HPA, 2007). In the EU in 2006 L. monocytogenes was recovered from 2.4% of bovine, 3.9% pork and 2.7% of poultry RTE products. A study by Vitas et al. (2004) reported a very high incidence of L. monocytogenes contamination in meat products over a 4 year period in Navarra, Spain: 34.9% of minced pork and beef samples and 36.1% of poultry samples tested were positive. L. monocytogenes was recovered from 7% of foods sampled in a Portuguese study, 60% of raw chicken muscle samples tested positive, 17.7% of raw red meat, 25% of ham samples, 2.3% of dry cured ham, 3.7% of Spanish style sausages and 11.1% of blood sausages (Menaa et al., 2004). Vitas et al. (2004) reported a L. monocytogenes incidence of 6.7% in cured meat products and 8.8% of RTE cooked meat products in Spain. An incidence of L. monocytogenes of 1.8% from food samples on the island of Cyprus in the years 1991–2000, with cured meats the most commonly contaminated food was reported by Eleftheriadou et al. (2002). Samelis and Metaxopoulos (1999) recovered L. monocytogenes from 6.7% of sliced vacuum packed cooked meats and 10% of country style sausages in Greece. The incidence of L. monocytogenes has decreased by 24% in the USA in the period of 1996–2003. In 2003 the incidence of listeriosis was 3.1 cases per 1 million population down from 7.9 cases per million in 1989 (Tappero et al., 1995; Voetsch et al., 2007). Listeria is, however, the second most common foodborne pathogen to cause death, second only to Salmonella in the USA (Mead et al., 1999). The Listeria prevalence in cow and bull processing plants in the USA was analysed by Guerini et al. (2007) and showed Listeria prevalence on hides was higher in cooler months. Prevalence on hides was as high as 92% (L. monocytogenes prevalence of 42%) in one processing plant in winter. Post-intervention, the prevalence of Listeria on carcasses in cold rooms fell to 0–6% for most of the processing plants examined in the study. Of the L. monocytogenes isolates 50% were the predominant serovar 4b (Guerini et al., 2007). In Brazil a study by Bersot et al. (2001) found L. monocytogenes in 26.7% of Mortadellas, an RTE processed meat product made from pork and beef, purchased from retail outlets. A study in Japan isolated L. monocytogenes from 12.2% of minced

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

77

Table 4.1 Significant L. monocytogenes outbreaks due to RTE foods Year

Serotype Cases Source

1998

4b

108

1999

4b

10

Rillettes

32

Country Deaths Miscarriage Reference

Frankfurters USA

14

4

France

2

1

5

1

4

3

8

3

1999/ 4b 2000 2000 NA

29

Pork tongue France in jelly Turkey meat USA

2002

4b

54

Turkey meat USA

2008*

NA

56

Deli meat

Canada

20

NA

Mead et al., (2006) INVS (2000) deValk et al. (2001) MMWR (2000) Gottlieb et al. (2006) PHAC (2008)

* Ongoing investigation. NA Not available.

beef, 20.6% of minced pork, 37% of minced chicken and 25% of minced pork/beef mixture (Inoue et al., 2000). Major outbreaks caused by L monocytogenes in RTE foods are outlined in Table 4.1. Listeria can survive the fermentation process and adapt to acidic environments such as those found in fermented meat products (Hill et al., 1995; Phan-Thanh et al., 2000).

4.2.3 Detection methods Traditional enrichment culture methods are the standard protocols followed by laboratories in the isolation of Listeria from foods (Allerberger, 2003). Tests need to be able to detect the lowest levels of Listeria contamination in 25 g of foods. Both the FDA and the International Organization for Standardization (ISO, 1998) have reference methods for Listeria detection. Both methods incorporate selective agents (acriflavin, naladixic acid, natamycin, cycloheximide and esculin) in the enrichment stages, as Listeria is slow growing and is easily outgrown by its competitors. The ISO method involves primary enrichment in half strength Fraser broth for 24 h at 30 °C, followed by secondary enrichment in Fraser broth for 48 h at 37 °C (Scotter et al., 2001). Buffered Listeria Enrichment broth is used for the enrichment of food samples by the FDA Bacteriological Analytical Manual (BAM) method (FDA, 2003). After the Enrichment broth step, it is plated onto selective agar, e.g. Oxford (Listeria isolation medium) agar (ISO, FDA), PALCAM (polymixin B, acriflavin, lithium chloride, ceftazidime, aesculi, d-mannitol) agar (ISO, FDA), MOX (magnesium oxalate) agar (FDA) or LPM (LiCl-phenylethanol-moxalactam agar (FDA). These media rely on the esculinase reaction based on β-d-glucosidase activity to differentiate Listeria from other bacteria. Listeria if present typically appears black with black zones in surrounding selective medium.

© Woodhead Publishing Limited, 2011

78

Processed meats

More rapid results can be obtained by the use of chromogenic media. Rapid’L.mono® agar (BioRad) is a commercial chromogenic media on which Listeria appears blue owing to the production of phosphatidylinositol-specific phospholipase C, an enzyme specific to L. monocytogenes and L. ivanovii. Results can be obtained within 24–48 hours. L. ivanovii colonies appear blue and are surrounded by a yellow halo (xylose-positive). L. monocytogenes are blue without a halo (xylose-negative). Other chromogenic agars available include CHROMagar0 Listeria (Mast Diagnostic) and BCM0 Listeria monocytogenes plating medium (Biosynth International) (Allerberger, 2003; Gasanov et al., 2005). Many commercial antibody tests are available including; Listeria VIA (3M Microbiology); Vidas® (Biomerieux); DuPont Lateral Flow System (DuPont Qualicon); Lister Test (VICAM). The use of molecular methods to detect nucleic acid, e.g. the polymerase chain reaction (PCR) requires a selective enrichment step of 24 to 48 hours, without this unreliable results are obtained. Furthermore, enrichment broths and food samples contain inhibitors which can give rise to PCR false negative results (Gasanov et al., 2005). Commercial PCR assay kits are available for the detection of Listeria from food and environmental sources. One such assay Probelia ® Listeria monocytogenes (Sanofi Diagnostic Pasteur) uses a probe labelled with peroxidise to detect amplicons attached to a microtiter plate. Other available assays include the BAX® Screening System (Qualicon, Wilmington, DE) (Allerberger, 2003). In 2002, the US Department of Agriculture’s (USDA) Food Safety and Inspection Service (FSIS) adopted the BAX® system to screen meat and poultry samples for L. monocytogenes (FSIS, 2002a). Other PCR commercial kits include: • TaqMan® Listeria monocytogenes Detection Kit (Applied BioSystems); • R.A.P.I.D. (Ruggedized Advanced Pathogen Identification Device) (Idaho Technology); • LightCycler foodproof Listeria Genus Detection Kit (Roche Diagnostics); • VIT-Listeria (vermicon AG, Munich).

4.3

Escherichia coli

Escherichia coli is found in the gastrointestinal tract of humans and other warm-blooded animals. Most are harmless; however, there are a number which are significant pathogens. E. coli serogroup O157 was recognised as a major foodborne pathogen after it was associated with an outbreak of severe bloody diarrhoeal illness, due to undercooked minced beef in hamburgers in a fast food chain in the USA (Riley et al., 1983; Wells et al., 1983). E. coli capable of producing verocytotoxins are grouped collectively as verocytotoxigenic E. coli (VTEC). In the USA they are known as Shiga

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

79

Table 4.2 Most commonly reported serotypes of VTEC for all human cases among EU Member States where serotypes were established Serotypes

2002

2003

2004

2005

2006

O157 O26 O103 O91 O145 O111 O146 O128 O55 Other

1189 (63%) 115 (6%) 172 (9%) 96 (5%) 44 (2%) 34 (2%) 29 17 15 178

1262 (63%) 143 (7%) 141 (7%) 86 (4%) 58 (3%) 34 (2%) 31 21 0 238

1283 (66%) 135 (7%) 55 (3%) 71 (4%) 69 (4%) 23 (1%) 34 15 17 247

1767 (70%) 169 (7%) 119 (5%) 82 (3%) 55 (2%) 45 (2%) 29 22 18 236

1726 (66%) 170 (7%) 116 (4%) 90 (3%) 86 (3%) 44 (2%) 30 18 24 300

Total

1889

2014

1949

2542

2604

Source: EFSA (2007) Table 3 page 15.

toxin producing E. coli (STEC) and are a subset of the enterohaemoharragic E. coli (EHEC). The EHEC produce verotoxins but also adhere to the large intestine causing lesions (FSAI, 2009; Gomez Lopez et al., 2000; Strockbine et al., 1986). There are a number of VTEC serogroups, the most important include E. coli O157; O26; O103; O91; O145 and O111. The most common serotypes reported by TESSy (a European Surveillance system) are listed in Table 4.2 (EFSA, 2007, p15). Several non-O157:H7 serotypes have been implicated as the cause of foodborne outbreaks and haemolytic uremic syndrome (HUS) in the USA, Europe and Australia. Studies from Canada, Europe, Argentina and Australia, suggest that non-O157:H7 STEC infections are as prevalent, or more so, than O157:H7 infections (Fey et al., 2000). The infective dose is quite small and can be as low as 10 cells (Boyce et al., 1995; MacDonald et al., 2003; Tilden et al., 1996). Infection with E. coli O157:H7 has the ability to cause haemorrhagic colitis (HS), HUS, thrombotic thrombocytopenic purpura (TTP) and death in the more severe cases. Death rate is also strongly linked to the age of the sufferer (Griffin et al., 1988). HUS occurs in 5–10% of infected people and renal failure in 5–6%. Some 3–5% of infected people die.

4.3.1 Routes of contamination and regulations for control One of the main sources of E. coli O157:H7 infection is cattle, where the gastrointestinal tract acts as a reservoir for VTEC (Chapman et al., 1993). E. coli O157:H7 has been found in up to 13% of cattle herds in Europe (Eriksson et al., 2005), originating mostly from the hide and faeces. Beef may become contaminated during slaughter and hide removal in the processing plant (Elder et al., 2000; Teagasc, 2005). Meat grinding results in the

© Woodhead Publishing Limited, 2011

80

Processed meats

pathogen spreading throughout a batch. As ground beef may include meat from numerous carcasses a single infected animal can therefore cause a large outbreak (Boyce et al., 1995; Tuttle et al., 1999; Wang et al., 1996; Wells et al., 1991). The main sources of cattle contamination are transport vehicles and cattle holding areas in the slaughter house (Arthur et al., 2007). Koohmaraie et al. (2007) reported an increase in hide contamination from 50.3% of cattle on farm to 94.4% after transportation and lairage holding. Undercooked meat, especially ground meat or mince, is a major source of infection. Other known food sources have included lettuce, sprouts, salami, unpasteurised milk and fruit juices. VTEC can survive in high acid in the stomach. The only effective way of ensuring beef is free from E. coli O157 when it reaches the consumer is by implementing HACCP during cattle slaughter and processing (Bolton et al., 2001). Consumer practices require meat to be cooked thoroughly as E. coli O157:H7 can persist in undercooked beef products. Internal temperature of hamburgers must reach 68 °C or above (FDA, 2005). The recent procedure for mechanical tenderising of beef using a blade or solid needles has resulted in a risk of transfer of E. coli O157 from the meat surface to the interior and a number of outbreaks have been reported due to this process in the USA (Laine et al., 2005). A report of best practice to control pathogens during tenderisation/enhancing whole muscle cuts was issued to the American Meat Industry (AMI) in 2006 (AMI, 2006). There is no requirement for minimum acceptable levels of VTEC O157 in end-products in EU regulations, as summarised by the Scientific Committee on Veterinary Measures relating to Public Health (SCVMPH): ‘due to sporadic occurrences and low prevalence, applying an end product microbiological standard for VTEC O157 is unlikely to deliver meaningful reductions in associated risk for the consumer’ (SCVMPH, 2003, p37). The EU recognises raw or undercooked beef, minced meat and fermented beef products amongst the highest risk vehicles for VTEC O157 (SCVMPH, 2003, p36). Proper handling practices need to be followed to avoid cross contamination (Rangel et al., 2005). The enforcement of strict hygiene practices in abattoirs is necessary to prevent VTEC cross-contamination. The low infective dose of this pathogen and its presence in processed meat samples is a worry to consumers as cross-contamination can easily occur during food preparation and contaminate uncooked foods. In 2002 the FSIS in the USA advised processing plants to reassess their HACCP programme in relation to E. coli O157:H7 (FSIS, 2002b). In 2004 FSIS issued Directive 10,010.1 (FSIS, 2004), which provided guidelines on raw ground beef sampling for E. coli O157:H7 and advised on the response to a positive sample. Following the reinforcement of these new rules the FSIS reported a 43.3% reduction in ground beef samples testing positive in 2004 compared with 2003. There has been more than 80% reduction in positive samples in the period 2000–2004 (FSIS, 2005). Washing of cattle

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

81

hides (Arthur et al., 2007; Koohmaraie et al., 2007) and chemical dehairing (Nou et al., 2003) have been reported as successfully reducing hide contamination prior to processing. In the United States in the late 1990s to reduce the prevalence of E. coli O157:H7 in raw processed meat products, a ‘test and hold’ process was implemented whereby a batch of meat is tested for E. coli O157:H7 and if the results are positive the batch is only used in cooked products or is rendered. This, however, is a very costly process (Koohmaraie et al., 2007). In Scotland, the rate of infection with E. coli O157:H7 is higher than other countries in Europe, in order to reduce the threat; a report was issued by the E. coli task force in 2001. The report implemented enhanced surveillance of HUS and other thrombotic microangiopathies as E. coli O157 was isolated in over 90% of childhood HUS cases (Pollock, 2005).

4.3.2 Incidences of VTEC in processed meats VTEC infections have been reported around the world and data can be obtained from reporting countries through the EnterNet surveillance site. Since 2 October 2007 the EnterNet network has been subsumed into the ECDC–Food and Waterborne disease unit. All historical reports and information are available at http://www.ecdc.europa.eu. There were 4641 VTEC cases from 26 countries reported in the EnterNet in 2005. Serogroup O157 was the predominant group, accounting for 63.3% of the cases (Anon., 2005a). For Quarter 3 of 2007 the ECDC reported 594 cases, of which serogroup O157 was 56.2% (334 of 594) and O157 phage type 8 the most common at 20% (66 of 332). Surveillance reporting shows O157 incidences decreasing with non-O157 serotypes increasing. The EU reported 4916 confirmed cases of VTEC in 2006, an incidence of 1.1 cases per 100,000 population, non-O157 serogroups accounted for over 50% of cases (EFSA, 2007, p152). In Ireland there were 167 cases of VTEC in 2007, with O157:H7 accounting for 94 cases followed by O26 with 13 cases (HSPC, 2008); this is an increase from 125 cases in 2006, which is approximately 3.2 cases per 100,000 persons. The likely prevalence of E. coli O157:H7 in minced beef products on sale in the Republic of Ireland is ≤3.6%. Fresh packaged burgers are most commonly contaminated with E. coli O157:H7. One study reported a prevalence of 4.46% (Cagney et al., 2004). A report commissioned by the FSAI in 2002 reported 2.8% of beef and hamburger products on retail sale in Ireland as being contaminated with E. coli O157:H7 (FSAI, 2002). The most recent report (FSAI, 2009), reported a crude incident rate per 100,000 populations to be 3.2%. The food implicated or suspected of being associated with VTEC outbreaks include minced meat, beef burgers, fermented meats (e.g. dry salami and pepperoni), blade tenderised beef and cooked meats. The prevalence of E. coli O157:H7 on beef trimmings in Irish abattoirs was reported at 2.4% (Cummins et al., 2008), and highlighted the

© Woodhead Publishing Limited, 2011

82

Processed meats

transfer of contaminated beef products from the processing plant to the retail market. Coia et al. (2001) reported a low incidence of 0.24% of VTEC O157 in raw beef products in south-east Scotland. In a study on beef doner kebabs in Turkey 26.25% of kebabs tested were positive for E. coli O157:H7. It is believed that processing of meat distributes pathogens from the surface of the cut, throughout the product where they are more protected from the heating process (Ulukanli et al., 2006). Contaminated foods of bovine origin especially undercooked ground beef consumption are responsible for the majority of E. coli O157:H7 infections in the USA (Griffin and Tauxe, 1991). What may be the first outbreak of E. coli O157:H7 due to a product containing pork meat alone was reported by Conedera et al. (2007). From 1982 to 2002, there were 350 outbreaks of E. coli O157:H7 from 49 states affecting 8598 people. Outbreaks peaked in 2000 after dramatically rising since 1994. Ground beef accounted for 33% of foodborne cases and 71% of those cases occurred between May and August (Rangel et al., 2005). The largest E. coli O157:H7 outbreak from ground beef (hamburger in a fast-food restaurant) occurred in 1993 affecting more than 700 people most of whom were children, four died (MMWR, 1993a; Tuttle et al., 1999). New temperature guidelines for ground beef in fast-food restaurants were brought in by the FDA in the wake of this outbreak. No fast-food hamburger associated outbreaks have occurred since 1995 (Rangel et al., 2005). The incidence of E. coli O157:H7 in the USA in 2007 was 1.20 cases per 100,000 population, with 545 cases (MMWR, 2008). E. coli O157 can survive in the acidic environments of fermented foods (Glass et al., 1992). Dry fermented sausages were traditionally considered safe due to low pH, low Aw and high salinity; however, the high fat content of fermented sausage allows the organism to survive and cause illness (Conedera et al., 2007). If present in raw sausage batter E. coli O157:H7 can survive the fermentation and drying process (Faith et al., 1998; Tilden et al., 1996). Significant outbreaks of E. coli O157:H7 are listed in Table 4.3. The emergence of non-O157:H7 serotypes and sorbitol fermenting serotypes is a real concern and their emergence may be underestimated due to limitations in current culture detection methods. Non-O157:H7 isolates have caused several outbreaks in the USA and in 2005, 501 cases were reported to the CDC Notifiable Diseases Surveillance System (NDSS). The most common non-O157:H7 serotypes in the USA include; O26 (24%), O103 (17%), O111 (13%), O45 (8%) and O121 (7%) (Brooks et al., 2007; CDC, 2007). In the EU the proportion of non O157-H7 serogroups increased to 52% during 2000–2004 (Anon., 2005a). In 2006 almost 50% of known VTEC serogroups causing human disease were non-O157:H7. In Italy O26 incidences increased (Tozzi et al., 2003). The Czech Republic and Germany reported the most numbers of non-O157:H7 serogroups (EFSA, 2007, p154). Data from other countries reporting cases due to non-O157

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

584 700 58

20 20

110 496

39

143

11 29 39

3

26

157

9

1993 1993 1993

1994 1994

1996 1996

1998

1999

2000 2002 2002

2004

2005

2005

2007

Bought in cooked meat Cooked cold meat

Seemerrolle beef Ground beef Cold smoked fermented beef sausage Pork dry fermented salami Minced beefburgers

Salami

Scotland

Wales

France

Italy

Germany USA Sweden

Canada

Canada

Sweden UK

ND† Meat

Fermented salami

USA USA

USA USA USA

Country

Dry-cured salami Ground beef

Hamburger Hamburger Hamburger

Source

†

* Not available. Haemolytic uremic syndrome. ‡ Thrombotic thrombocytopenic purpura.

Cases

NA

NA

20

2

1 7 13

42

14

NA 127

3 3

9

171

Hospitalisation

Significant E. coli O157:H7 outbreaks

Year

Table 4.3

NA

Bloody diarrhoea, abdominal pain, nausea Bloody diarrhoea, gastroenteritis Bloody diarrhoea

Bloody diarrhoea, abdominal pains, nausea, subjective fever, headache, vomiting NA Diarrhoea (bloody and non-bloody), abdominal cramps NA Diarrhoea Bloody diarrhoea Bloody diarrhoea Abdominal cramps Diarrhoea (bloody and non-bloody), abdominal cramps, nausea, vomiting, headache, fever. Non-bloody diarrhoea NA Diarrhoea

NA

Symptoms

NA

NA

13

NA

0 5 9

2 5

29 27 & TTP‡

1 1

3

41

HUS#

NA

1

0

0

0 NA 0

NA 0

0 20

NA NA

4 4 NA*

Deaths

Stirling et al. (2007)

Salmon (2005)

Anon. (2005b)

Conedera et al. (2007)

Werber et al. (2002) MMWR (2002a) Sartz et al. (2008)

Williams et al. (2000) MacDonald et al. (2003)

Ziese et al. (1996) Pennington (1998)

MMWR (1995a) MMWR (1993b)

MMWR (1993a) Tuttle et al. (1999) Cieslak et al. (1997)

References

84

Processed meats

serogroups include; Ireland (McMaster et al., 2001); Belgium (De Schrijver et al., 2008); Italy (Capriolia et al., 1994); Denmark (Ethelberg et al., 2007a); Norway (Schimmer et al., 2008); Germany (Werber et al., 2002); USA (CDC, 2007); Japan (Nishikawa et al., 1999); Israel (Shazberg et al., 2003) and Australia (MMWR, 1995c). With regard to E coli O26, the second most prevalent serogroup, Dambrosio et al. (2007) reported 1.2% of minced beef samples on sale in Southern Italy to contain O26. Murphy et al. (2005) reported a lower prevalence of 0.25% in minced beef in Ireland. O’Hanlon et al. (2005) recovered E. coli O26 from 4.6% of minced meat samples and E. coli O111 from 1.5% of samples tested. Oteiza et al. (2006) isolated E. coli O157:H7 and E. coli O26 from 2% and 1% of morcilla Argentinean blood sausage.

4.3.3 Detection methods Detection methods include the use of selective culture media, immunomagnetic separation and immune kits as well as conventional PCR and real time PCR. A study by Ratnam et al. (1988) demonstrated that E. coli O157:H7 had unique biochemical properties that differed from other E. coli where 100% positive reactions for raffinose and dulcitol and 100% negative reaction for sorbitol and beta-glucuronidase were observed. SorbitolMacConkey agar can be used as a culture medium for the detection of O157 isolates based on the fact the serogroups do not ferment sorbitol (March and Ratnam, 1986). Colourless sorbitol negative colonies can be assayed for the O157 antigen using commercial kits (March and Ratnam, 1989). The ISO has a culture method for isolation of E. coli O157:H7 based on these findings (ISO, 2001). A method involving the addition of cefixime and potassium tellurite to Sorbitol-MacConkey agar, together with an enrichment step has been developed due to increases in foodborne outbreaks (FDA, 2001). The method involves an enrichment phase: E. coli O157:H7 colonies are isolated using magnetic beads coated in antibodies against O157 and plated on sorbital MacConkey agar supplemented with cefixime and tellurite. Sorbitol-fermenting VTEC O157 appears as pink colonies on this medium. The first report of sorbitol fermenting E. coli O157:H7 was from Germany in 1988 during a HUS outbreak (Karch et al., 1993). Cases of sorbitolfermenting E. coli O157:H7 have also occurred in Ireland (HSPC, 2007); the UK (HPA, 2006); Scotland (Taylor et al., 2003) and Germany (Ammon et al., 1999). The method of isolation based on the premise of O157 not fermenting sorbitol clearly cannot be used in such cases and many therefore go undetected. Further tests using antibody agglutination should be performed on isolates from patients with clinical symptoms suggestive of VTEC (HPA, 2006). Culture methods are recognised for the detection of O157:H7 isolates; however, there is no certified ISO method for the detection of non-O157

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

85

isolates in foods (O’Hanlon et al., 2005). Methods have been described by Catarame et al. (2003), with the use of tryptone soy broth supplemented with cefixime (50 μg l−1), vancomycin (40 mg l−1) and potassium tellurite (2.5 mg l−1). MacConkey agar supplemented with cefixime with lactose replaced by rhamnose was found to be the optimum agar for recovery of E. coli O26. Chromcult agar supplemented with cefixime (50 μg ml−1), cefsulodin (5 mg l−1) and vancomycin (8 mg l−1) was reported to recover the optimum amount of E. coli (Catarame et al., 2003). As well as conventional PCR and real time PCR detection methods, Hara Kudo et al. (2008) described a loop-mediated amplification (LAMP) assay method that gave good results in the detection of E. coli O157 and O26 from ground beef and alfalfa sprouts. LAMP may be faster, more specific and more user friendly than conventional PCR. O’Hanlon et al. (2005) compared a real time PCR method for the detection of E. coli O26 and O111 from minced beef in Ireland to the traditional culture method. The study found that real time PCR was more sensitive in detecting the pathogens in frozen samples. Shiga toxin enzyme immunoassay (StxEIA) is increasingly used by laboratories (MMWR, 2007). Few studies exist on the prevalence of non-O157 isolates in foods due to the lack of standard isolation methods. It is believed the majority of non-O157 isolates and sorbital fermenting O157 isolates are missed by laboratories using the standard culture method. Commercial molecular kits available include: • WarnexTM Real-Time PCR Rapid Pathogen Detection System for E. coli O157:H7/NM; • LightCycler ® foodproof E. coli O157:H7 Detection Kit (Roche); • Ruggedized advanced pathogen identification device (RAPID) system E. coli O157 kit (Idaho Technology, Inc.).

4.4

Salmonella

Salmonellae are the cause of two diseases called salmonellosis: enteric fever (typhoid), resulting from bacterial invasion of the bloodstream, and non-typhoid, acute gastroenteritis, resulting from a foodborne infection/ intoxication. Salmonella is a member of the Enterobacteriacae family (Adams and Moss, 2000, p238). Salmonella are Gram-negative, facultative anaerobes, non-spore forming short rods of 1–2 μm. This chapter will discuss only the non-typhoid acute gastroenteritis Salmonella. Although the taxonomy of Salmonella can be confusing, most human-associated Salmonella serotypes are members of Salmonella enterica subspecies enterica (Coburn et al., 2007). More than 2500 serotypes have been described. Most serotypes are motile via peritrichous flagella except for a few, most notably S. Gallinarium and S. Pullorum.

© Woodhead Publishing Limited, 2011

86

Processed meats

The infective dose varies according to serotype, food vehicle and the health of the host and can be as low as 20 cells to 106 cells (Adams and Moss, 2000, p241). In Europe and the USA the predominant serotypes are S. Enteritidis, S. Typhimurium, S. Virchow and S. Hadar. S. Enteritidis and S. Virchow are mostly associated with chicken products and S. Hadar with turkey, while S. Typhimurium has a broader host range ranging from cattle, pigs, poultry and sheep (Cohen and Tauxe, 1986; Threlfall, 2002). Symptoms of infection with Salmonella range from asymptomatic carriage to meningitis or osteomyelitis but most often Salmonella infection results in uncomplicated gastroenteritis illness (Cohen and Tauxe, 1986). Symptoms include: fever, diarrhoea, headache, abdominal pain and vomiting. The incubation period is generally 6–72 hours. The symptoms generally last 2–7 days, while faecal shedding may continue for as long as 3 months (Adams and Moss, 2000, p240; Hohmann, 2001). In healthy non-immunocompromised individuals illness is usually self-limiting with a death rate of approximately 0.1% and antibiotic therapy is generally not required (Gordon, 2008; Threlfall 2002; Voetsch et al., 2004). Antimicrobial therapy may be required in elderly and immunocompromised individuals or in cases of severe dehydration and bacteraemia (Frenzen et al., 1999; Little et al., 2008; Piddock, 2002). Children under the age of 5 run the greatest risk of developing Salmonella infection (EFSA, 2007, p27; MMWR, 2008). The incidence of salmonellosis has increased dramatically since the middle of the last century, owing to changes in food production practices and the industrialisation of the food processing industry, which has allowed for the rapid and widespread distribution of contaminated food (Cohen and Tauxe, 1986). In the USA, salmonellosis accounts for 9.7% of foodborne illness and 30.6% of deaths associated with foodborne infection (Frenzen et al., 1999, Mead et al., 1999). In the EU there were 160,649 confirmed cases of salmonellosis in 2006, a rate of 34.6 cases per 100,000 population (EFSA, 2007, p25). In the UK Salmonella is responsible for 53% of foodborne disease outbreaks (Hughes et al., 2007). The Salmonella incidence in Ireland stands at 10.76 cases per 100,000 population (HPSC, 2008).

4.4.1 Routes of contamination and regulations for control The link between human salmonellosis and host animals is most clear in poultry. However, Salmonella has been isolated from all food animals. Meat is a significant source of Salmonella infection. Red meat was linked to 14% of Salmonella cases in the UK between 1992 and 2003, of which pork was the most common vehicle (Hughes et al., 2007; Smerdon et al., 2001). Salmonella was found in 2% of faecal, 2% rumen and 7.6% of carcass samples from cattle in an Irish abattoir, the most common serotype was S. Dublin followed by S. Typhimurium phage type DT104 and S. Agona (McEvoy et al., 2003).

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

87

EU Commission regulations EC 1003/2005 (EC, 2005b) amended the EC 2160/2003 Regulation (EC, 2003) on the control of salmonella and other specific foodborne zoonotic agents in Member States, with a new target for reduction of certain Salmonella serotypes (Enteritidis; Hadar; Infantis; Typhimurium; Virchow) in breeding flocks of Gallus gallus (domesticated fowl). Under the regulation, each Member State must implement a control programme covering all stages of food production and must include animal feed production, primary animal production, and processing and preparation of food of animal origin. The EC 1003/2005 set a target for breeding flocks, that no more than 1% of chicken breeding flocks with 250 birds or more, test positive for Salmonella serotypes that cause disease in humans by 2009. In the USA the FSIS established an initiative to reduce Salmonella prevalence in raw meat and poultry products in 2006 under a Federal Register Notice, Salmonella Verification Sample Result Reporting: Agency Policy and use in Public Health Protection (71 FR 9772) (FSIS, 2006). The initiative based on HACCP, places meat processing plants in different categories based on performance standards. Plants that fail to meat standards are tested more frequently than those that comply with standards.

4.4.2 Incidences of Salmonella in processed meats Multiple studies around the world report Salmonella incidences in meat but many go unreported. Significant outbreaks occur from time to time and relevant outbreaks in pork and beef products are outlined in Tables 4.4 and 4.5. Worldwide incidences of Salmonella in processed meat include a study in the Abruzzi region of Italy in 2004 reported 9.7% on pork products contaminated with Salmonella of which 17.6% were fresh sausages and 8.9% dry sausages (Giovannini et al., 2004). Salmonella was detected in 8.6% of sausages sampled from the Devon area of the UK in 2000 (Mattick et al., 2002) with cheaper sausages having higher Salmonella prevalence than more expensive sausages. In Ireland two studies of interest include Jordan et al. (2006) who reported a Salmonella prevalence of 3% in raw poultry meat and turkey while 2% and 0.16% of pork and beef products tested positive for Salmonella respectively over a three year period from 2002 to 2004. 0.2% of cooked poultry meat products tested positive for Salmonella in the same study. A study by Duffy et al. (2001), reported a Salmonella prevalence of 7.3% in retail ground pork products and 12.5% in pre-packaged ground pork products. Salmonella prevalence of 24.4% in sausages from Porto Alegre, Brazil (Mürmann et al., 2008). Pork and beef were responsible for 3% and 6.5% of Salmonella outbreaks in the USA respectively (Lynch et al., 2006). A study by Zhao et al. (2001) examined the prevalence of foodborne pathogens in meat products in the Washington, DC, area. The study found Salmonella contamination in 3.3% of pork products, 1.9% of beef products, 2.6% of turkey meats and the highest incidence in chicken at 4.2%. A later study by Zhao et al. (2006) recovered Salmonella

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

S. Goldcoast

S. Typhimurium DT104A

S. Typhimurium

S. Manhattan

S. Typhimurium DT12

S. Enteritidis S. 4,[5],12:i:- DT 193

S. Typhimurium DT12

2001

2004

2005

2005

2005

2006 2006

2007

10

49 155

26

69

27

63

44

12

83

101

Cases

ND, not determined, NA, not available.

2001

1995

S. Typhimurium DT124 S. Typhimurium DT193 S. Uganda

Salmonella Strain

Cured sausage

Pork Pork product

Pork

Sausages

Fermented sausage Coralline fermented Salami Salami

Carnitas fried Pork pieces

Salami

Salami sticks

Suggested Vehicle

Village fair Child day care centre, elderly & handicapped institutions Ferry boat & domestic

NA

NA

NA

NA

NA

Grocery store

NA

NA

Settings

Significant Salmonella outbreaks due to pork products

1988

Year

Table 4.4

Denmark & Norway

Latvia Luxembourg

Denmark

Sweden, Italy & Norway France

Italy

Germany

USA

Italy

England

Country

ND

Slaughter-house contamination Pig head Slaughter-house contamination Food preparation Poor hygiene procedures in swine abattoir

Processed meat

Contaminated pig

Cross-contamination Sick chef in food production ND

Insufficient ripening

ND

Suggested Source

Nygård et al. (2007)

Patrina et al. (2006) Mossong et al. (2007)

Torpdahl et al. (2006)

Noël et al. (2006)

Hjertqvist et al. (2006)

Luzzi et al. (2007)

Bremer et al. (2004)

Jones et al. (2004)

Pontello et al. (1998)

Cowden et al. (1989)

Reference

© Woodhead Publishing Limited, 2011

S. Typhimurium DT104 S. Newport S. Typhimurium S. Typhimurium DT104 S. Typhimurium DT104 S. Typhimurium DT104

2000

32

4

47 31 169

35

31 12 11 26

158

Cases

ND, not determined, NA, not available.

2005

2005

2002 2004 2005

1998

S. Typhimurium S. Montevideo S. Kentuky S. Coeln

S. Typhimurium

1994

1995

Salmonella strain

Carpaccio beef

Frozen minced beef

Frozen mince Beef hamburgers Minced beef Minced beef Raw beef product

Minced beef

Beef jerky

Raw minced beef

Suggested vehicle

International

Local

National Local International

Local

Local

Local

Local

Setting

Significant outbreaks of Salmonella due to beef products

Year

Table 4.5

Denmark

Norway

USA USA The Netherlands

France

France

USA

USA

Country

Food producer

Imported raw beef

NA Meat processing plant Imported beef

Uncooked meat

Meat produce

Butcher shop Meat grinder ND

Suggested source

Isakbaeva et al. (2005) Ethelberg et al. (2007b)

Haeghebaer et al. (2001) Haeghebaer et al. (2001) MMWR (2002b) MMWR (2006) Kivi et al. (2007)

Roels et al. (1997) MMWR (1995b)

Reference

90

Processed meats

from 6% of meat samples on retail sale, the majority recovered from ground turkey (52%) followed by chicken breast (39%). A report in 2002 from the DC area, reported a Salmonella prevalence of 16% in ground pork and 6% in ground beef with 35% of chicken and 24% of turkey ground meat samples testing positive (White et al., 2001). Some 1.1% of cattle and 2.7% of ground beef products in the USA were contaminated with Salmonella according to a report by the FSIS in 2007 (FSIS, 2008). This showed a reduction from an earlier survey of ground beef in the USA in 1993–1994 when 7.5% of ground beef samples were contaminated with Salmonella (FSIS, 1996). 7.7% of ground turkey products and 1.1% of RTE turkey meat samples on retail sale in the Midwest USA tested positive for Salmonella (Khaitsa et al., 2007). An international outbreak of Salmonella Agona affecting 119 people was linked to an Irish meat processing plant in 2008: the processing line was contaminated and chicken and bacon products became infected. The products were for the ‘made to order’ sandwich trade (O’Flanagan et al., 2008). Ground horse meat in France was responsible for 14 cases of salmonellosis due to S. Newport; the suggested source was a processing plant (Espié, 2003).

4.4.3 Antibiotic resistant Salmonella Antimicrobial resistant Salmonella spp. have emerged as a major problem in recent years. In Europe over 60% of Salmonella isolates are now resistant to at least one antimicrobial agent (Meakins et al., 2008). Chloramphenicol, ampicillin and trimethoprim-sulfamethoxazole have been used in the past to treat Salmonella infections (Cohen and Tauxe, 1986) but owing to the increase in antibiotic resistance the choice of antimicrobial agents available to treat invasive infection in humans is now extremely limited (Threlfall, 2002). Increase in resistance to fluoroquinolones especially ciprofloxacin is a major concern to physicians worldwide as they are now the drug of choice in the treatment of invasive salmonella infections (Gorman and Adley, 2003). In the EU, S. Typhimurium phage type DT104 is now the most common S. Typhimurium phage type isolated from humans (EFSA, 2007, p30) and multi-resistant S. Typhimurium DT104 has emerged as a worldwide problem. S. Typhimurium DT104 chromosomally resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides and tetracycline (R-type ACSSuT) was identified in 1984 for the first time in the UK and the number of isolates began to rise significantly from the early 1990s (Gorman and Adley 2003; Threlfall et al., 1997; Wall et al., 1994). In the USA the proportion of S. Typhimurium isolates that were R-type ACSSuT rose from 0.6% at the start of the 1980s to 34% in 1996 (Glynn et al., 1998). Cattle are the main vehicle for S. Typhimurium DT104 human infection but sheep, pigs, goats, chickens and turkeys are all known carriers (Daly et al., 2000; Helms et al., 2005; Threlfall et al., 1996). Emergence of multiresistant S. Typhimurium with

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

91

additional resistance to ciprofloxacin coincided with the licensing of Enrofloxacin for veterinary usage. Resistance is also increasing among S. Enteritidis isolates. The EnterNet reported a dramatic shift in the predominant phage types PT4 of S. Enteritidis in 2004. 61.8% of S. Enteritidis isolates reported in 1998 were PT4. In 2003 this figure had fallen to 32.1% with an increase in non-PT4 phage types in both proportion and number. PT1 increased from 8.6% in 1998 to 17.8% in 2003. PT8 numbers have increased nearly 85% over the 6 years to account for 13% of S. Enteritidis isolates in Europe (Fisher and Meakins, 2006). In the UK, 76% of S. Enteritidis PT1 isolates in 2004 showed reduced susceptibility to ciprofloxacin in England and Wales (Threlfall et al., 2006). It is believed that eggs imported from Spain were responsible for the increase in non-PT4 isolates in the UK at the start of this decade (Gillespie, 2005). In the USA, S. Enteritidis (17%), S. Typhimurium (16%), S. Newport (10%) and S. Javiana (5%) account for nearly one-half of the human isolates (MMWR, 2008). The number of S. Newport isolates in the USA has increased from 5% to 10% of the total number of Salmonella serotypes reported to CDC during 1997–2001, multidrug resistant S. Newport appears to be driving this increase. The first reported outbreak of multiresistant S. Newport due to undercooked ground beef occurred in 2002 (MMWR, 2002b). S. Newport strains with resistance to third generation cephalosporins such as ceftriaxone, important in the treatment of invasive Salmonellosis in children (MMWR 2002b), is of great concern. The most common multidrug resistant S. Newport phenotype in the USA is NewportMDRAmpC (with reduced susceptibility to ceftriaxone) which has spread rapidly, increased in prevalence from 1% to 21% during 1998–2003. It is believed the use of ceftiofur (cephalosporin) in agricultural medicine in the USA could have selected for S. Newport-MDRAmpC (CDC, 2006; Zhao et al., 2003). Cattle are the main reservoir for this Salmonella isolate but other animals can also become infected including pigs, horses and dogs. S. Newport-MDRAmpC has also been identified in France (Egorova et al., 2008; Espié, 2003).

4.4.4 Detection methods Detection of Salmonella in foods is outlined in the FDA BAM, (FDA, 2007), ISO 6579 (ISO, 2002) and HPA (2008). Culture methods involve preenrichment in buffered peptone water (HPA, ISO) or lactose broth (FDA) for 24 hours at 35–37 °C. An aliquot of the pre-enrichment culture is added to selective enrichment broths such as Rappaport-Vassiliadis medium (RV), selenite cystine broth, Muller-Kauffmann tetrathionate novobiocin broth (MKTTn), tetrathionate broth. Following enrichment for 24 and 48 hours, an aliquot of each is streaked onto selective agar xylose lysine desoxycholae (XLD) agar, Brilliant Green (BG) agar, Hektoen enteric (HE) agar, bismuth

© Woodhead Publishing Limited, 2011

92

Processed meats

sulfite (BS) agar. On XLD, Salmonella ferment xylose, decarboxylate lysine and produce hydrogen sulphide and typical colonies appear pink to red with or without black centres. On BG Salmonella colonies appear red surrounded by bright red medium. HE agar colonies appear blue-green to blue with or without black centres. BS agar colonies appear brown, grey or black. Suspected Salmonella colonies are identified biochemically and serologically. Rapid methods are slowly becoming available and validated for use in public health laboratories. Some rapid kits include: • DuPont Qualicon BAX® system (Oxoid Limited) has been approved by the AOAC (American Association of Analytical Communities), USDA FSIS, Health Canada Certification, Association Française de Normalisation (AFNOR) and the Ministry of Agriculture in Brazil; • TaqMan® Salmonella enterica Detection Kit (Applied Biosystems) approved by AOAC and AFNOR; • Foodproof® Salmonella (Merck KGaA) based on real time PCR approved by AOAC- RI (Research Institutes) and the National Veterinary Institute Norway (NordVal) (Qvist, 2007).

4.5 Conclusions Food is a silent vehicle for spreading pathogens across country borders. Global trade in food has increased and with it international outbreaks due to contaminated foods are becoming more common. However, the presence of microbial pathogens that cause human infection in the food chain is unacceptable. HACCP protocols have delivered in controlling microbial pathogens in the food processing industry. Monitoring and surveillance are still important but must be done with increased regulatory controls. The food industry is constantly looking at faster, more sensitive pathogen detection methods due to the need to distribute perishable products as soon as possible. Culture detection methods and immunoassay tests (based on the use of specific antibodies binding to antigens) are in wide use because of their simplicity, low cost and high sample throughput. Commercial enzymelinked immunosorbent assays (ELISAs) require a minimum number of organisms to successfully detect the presence of a pathogen, therefore to detect smaller numbers an enrichment step are required. Fluorescent labelled antibodies for use with flow cytometry or fluorescence microscopy and lateral flow immunoprecipitation are emerging immunological monitoring test systems. Antibiograms, and analysis at the DNA level using pulsedfield gel electrophoresis (PFGE), is emerging as a gold standard to distinguish select organisms. The USA PulsetNet focuses on organisms such as Escherichia coli O157:H7, Salmonella, Shigella, Listeria and Campylobacter. PulseNet Europe has established a database system to detect infection clusters and investigates outbreaks of Salmonella, verocytotoxigenic E. coli (VTEC) and Listeria monocytogenes http://www.cdc.gov/pulsenet/.

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

93

The emerging field of nanotechnology holds the potential for real time detection of trace microbial contamination. Nanosensors can even gain access into hard to reach process areas/crevices that form harbourage sites for pathogens and other microbes (Adley et al., 2009; Velusmy et al., 2009). One significant aspect to be considered in the monitoring of foodborne pathogens is the viable but non-culturable (VBNC) bacteria. This form of bacteria was defined in 1982 (Xu et al., 1982) when it was demonstrated that bacteria that have lost their ability to reproduce in culture can still survive and exist with metabolic activity, and have the ability to reproduce in suitable conditions. Recent studies have shown that most of the human pathogens (Campylobacter spp., Escherichia coli, Francisella tularensis, Helicobacter pylori, Legionella pneumophila, Listeria monocytogenes, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Vibrio cholerae, V. parahaemolyticus, V. vulnificus) have a VBNC form (Rowan, 2004). Stress condition may cause the bacteria to develop to the VBNC form, as in a food processing environment. Greater transparency at all levels of food safety policy worldwide is required, in particular with the global transport of food from countries with poor safety regulations and control measures. The growing number of national standards for food safety control and management has led to confusion and duplication. Published in September 2005, ISO 22000 Food safety management systems – requirements for any organization in the food chain, aims to be an international, auditable standard defining food safety management along the entire food chain – ‘to ensure that there are no weak links’ and will possibly promote organisations such as producers of equipment, packaging material, cleaning agents, additives and ingredients to bring safe food to the public at large. We as consumers are entitled to safe food without chemical, physical and/or microbial contamination.

4.6 References adams m r & moss m o (2000), ‘Bacterial agents of foodborne illness’ in Food Microbiology, 2nd ed, The Royal Society of Chemistry, 184–271. adley c c, arshak k, molnar c, oliwa k & vijayalkshmi v (2009), ‘Design of specific DNA primers to detect the Bacillus cereus group species. IEEE Sensors Application Symposium, New Orleans; February 2009; (SAS 2009): 236–239 doi: 10.1109/ SAS.2009.4801807 allerberger f (2003), ‘Listeria: growth, phenotypic differentiation and molecular microbiology’, FEMS Immunology and Medical Microbiology, 35, 183–189. amato-gauci a & ammon a (2008), ‘The surveillance of communicable diseases in the European Union – a long term strategy’, Eurosurveillance, 13, Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=18912 ami (2006), ‘Best Practices: Pathogen Control During Tenderizing/Enhancing of Whole Muscle Cuts’, American Meat Industry, http://www.aamp.com/foodsafety/ Guidelines.asp

© Woodhead Publishing Limited, 2011

94

Processed meats

ammon a, petersen l r & karch h (1999), ‘A large outbreak of hemolytic uremic syndrome caused by an unusual sorbitol-fermenting strain of Escherichia coli O157:H−’, The Journal of Infectious Diseases, 179, 1274–1277. anon (2005a), ‘Enter-net annual report: 2005 – Surveillance of Enteric Pathogens in Europe and Beyond, Enter-net surveillance hub’, HPA, Centre for Infections, Colindale, London. anon (2005b), ‘French multi-agency outbreak investigation team. Outbreak of E. coli 0157:H7 infections associated with a brand of beefburgers in France’, Eurosurveillance, 10, available online: http://www.eurosurveillance.org/ViewArticle. aspx?ArticleId=2825 arthur t m, bosilevac j m, brichta-harhay d m, guerini m n, kalchayanand n, shackelford s d, wheeler t l & koohmaraie m (2007), ‘Transportation and lairage environment effects on prevalence, numbers, and diversity of Escherichia coli O157:H7 on hides and carcasses of beef cattle at processing’, Journal of Food Protection, 70, 280–286. becker b, jordan s & holzapfel w h (2005), ‘Rapid and specific detection of Listeria monocytogenes in smoked salmon with BAX®-PCR’, Food Control, 16, 717–721. doi:10.1016/j.foodcont.2004.06.009 beresford m r, andrew p w & shama g (2001), ‘Listeria monocytogenes adheres to many materials found in food-processing environments’, Journal of Applied Microbiology, 90, 1000–1005. berrang m e, meinersmann r j, northcutt j k & smith d p (2002), ‘Molecular characterization of Listeria monocytogenes isolated from a poultry further processing facility and from fully cooked product’, Journal of Food Protection, 65, 1574–1579. bersot l s, landgraf m, franco b d g m & destro m t (2001), ‘Production of mortadella: behaviour of Listeria monocytogenes during processing and storage conditions’, Meat Science, 57, 13–17. bolton d j, byrne c, catarane t & sheridan j j (2001), ‘Control of Escherichia coli 0157:H7 in beefburgers’, Teagasc Final Report NFC No. 29. borucki m k & call d r (2003), ‘Listeria monocytogenes serotype identification by PCR’, Journal of Clinical Microbiology, 41, 5537–5540. doi: 10.1128/JCM.41. 12.5537–5540.2003 boyce t, swerdlow d l & griffin p (1995), ‘Escherichia coli O157:H7 and the hemolytic-uremic syndrome’, The New England Journal of Medicine, 333, 364–368. bremer v, leitmeyer k, jensen e, metzel u, meczulat h, weise e, werber d, tschepe h, kreienbrock l, glaser s & ammon a (2004), ‘Outbreak of Salmonella Goldcoast infections linked to consumption of fermented sausge, Germany 2001’, Epidemiology and Infection, 132, 881–887. doi: 10.1017/S0950268804002699 brooks j t, sowers e g, wells j g, greene k d, griffin p m, hoekstra r m & strockbine n a (2007), ‘Non-O157 Shiga toxin-producing Escherichia infections in the United States, 1983–2002’, Journal of Infectious Diseases, 192, 1422–1429. cagney c, crowley h, duffy g, sheridan j j, o’brien s, carney e, anderson w, mcdowell d a, blair i s & bishop r h (2004), ‘Prevalence and numbers of Escherichia coli O157:H7 in minced beef and beef burgers from butcher shops and supermarkets in the Republic of Ireland’, Food Microbiology, 21, 203–212. doi: 10.1016/S0740-0020(03)00052-2 caprioli a, luzzi i, rosmini f, resti c, edefonti a, perfumo f, farina c, goglio a, gianviti a & rizzonoi g (1994), ‘Communitywide outbreak of hemolytic-uremic syndrome associated with non-O157 verocytotoxin-producing Escherichia coli’, The Journal of Infectious Diseases, 169, 208–211. catarame t m g, o’hanlon k a, duffy g, sheridan j j, blair i s & mcdowell d a (2003), ‘Optimization of enrichment and plating procedures for the recovery of

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

95

Escherichia coli O111 and O26 from minced beef’, Journal of Applied Microbiology, 95, 949–957. doi: 10.1046/j.1365-2672.2003.02065.x cdc (2006), ‘National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS): 2003, human isolates final report’, Department of Health and Human Services, Atlanta, USA. cdc (2007), ‘Bacterial Foodborne and Diarrheal Disease National Case Surveillance. Annual Report, 2005’, US Department of Health and Human Services, Centers for Disease Control and Prevention, Atlanta, USA. chapman p a, siddons c a, wright d j, norman p, fox j & crick e (1993), ‘Cattle as a possible source of verocytotoxin-producing Escherichia coli O157 infections in man’, Epidemiology and Infection, 111, 439–447. cieslak p r, noble s j, maxson d j, empey l c, ravenholt o, legarza g, tuttle j, doyle m p, barrett t j, wells j g, a m mc namara & griffin p m (1997), ‘Hamburger-associated Escherichia coli O157:H7 infection in Las Vegas: a hidden epidemic’, American Journal of Public Health, 87, 176–180. coburn b, grassl g a & finlay b b (2007), ‘Salmonella, the host and disease: a brief review’, Immunology and Cell Biology, 85, 112–118. doi: 10.1038/sj.icb.7100007 codex (1997), ‘Principles for the establishment and application of microbiological criteria for foods CAC/GL 21 – 1997’, www.codexalimentarius.net cohen m l & tauxe r v (1986), ‘Drug-resistant Salmonella in the United States: an epidemiologic perspective’, American Association for the Advancement of Science, 234, 964–969. coia j e, johnston y, steers n j & hanson m f (2001), ‘A survey of the prevalence of Escherichia coli O157 in raw meats, raw cow’s milk and raw-milk cheeses in south-east Scotland’, International Journal of Food Microbiology, 66, 63–69. conedera g, mattiazzi e, russo f, chiesa e, scorzato i, grandesso s, bessegato a, fioravanti a & caprioli a (2007), ‘A family outbreak of Escherichia coli O157 haemorrhagic colitis caused by pork meat salami’, Epidemiology and Infection, 135, 311–314. doi:10.1017/S0950268806006807 cowden j m, o’mahony m, bartlett c l r, rana b, smyth b, lynch d, tillett h, ward l, roberts d, gilbert r j, baird-parker a c & kilsby d c (1989), ‘A national outbreak of Salmonella typhimurium DT124 caused by contaminated salami sticks’, Epidemiology and Infection, 103, 219. cummins e, nally p, butler f, duffy g & o’brien s (2008), ‘Development and validation of a probabilistic second-order exposure assessment model for Escherichia coli O157:H7 contamination of beef trimmings from Irish meat plants’, Meat Science, 79, 135–154. doi: 10.1016/j.meatsci.2007.08.015 daly m, buckley j, power e, o’hare c, cormican m, cryan b, wall p g & fanning s (2000), ‘Molecular characterization of Irish Salmonella enterica Serotype Typhimurium: detection of Class I integrons and assessment of genetic relationships by DNA amplification fingerprinting’, Applied and Environmental Microbiology, 66, 614–619. dambrosio a, lorusso v, quaglia n c, parisi a, salandra g l, virgilio s, mula g, lucifora g, celano g v & normanno g (2007), ‘Escherichia coli O26 in minced beef: prevalence, characterization and antimicrobial resistance pattern’, International Journal of Food Microbiology, 118, 218–222. de schrijver k, buvens g, possé b, branden d v d, oosterlynck o, zutter l d, eilers k, piérard d, dierick k, damme-lombaerts r v, lauwers c. & jacobs r (2008), ‘Outbreak of verocytotoxin-producing E. coli O145 and O26 infections associated with the consumption of ice cream produced at a farm, Belgium, 2007’, Eurosurveillance, 13, available online: http://www.eurosurveillance.org/ViewArticle. aspx?ArticleId=8041 de valk h d, vaillant v, jacquet c, rocourt j, querrec f l, stainer f, quelquejeu n, pierre o, pierre v, desenclos j.-c & goulet v (2001), ‘Two consecutive nation-

© Woodhead Publishing Limited, 2011

96

Processed meats

wide outbreaks of listeriosis in France, October 1999–February 2000’, American Journal of Epidemiology, 154, 944–950. de valk h, jacquet c, goulet v, vaillant v, perra a, simon f, desenclos j c & martin p (2005), ‘Surveillance of Listeria infections in Europe’, Eurosurveillance, available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=572 denny j & mclauchlin j (2008), ‘Human Listeria monocytogenes infections in Europe – an opportunity for improved European surveillance’, Eurosurveillance, 13, 1–5, available online: http://www.eurosurveillance.org/ViewArticle. aspx?ArticleId=8082 duché o, trémoulet f, glaser p & labadie j (2002), ‘Salt stress proteins induced in Listeria monocytogenes’, Applied and Environmental Microbiology, 68, 1491– 1498. doi: 10.1128/AEM.68.4.1491–1498.2002 duffy e a, belk k e, sofos j n, bellinger g r, pape a & smith g c (2001), ‘Extent of microbial contamination in United States pork retail products’, Journal of Food Protection, 64, 172–178. ec (2003), ‘Regulation (EC) No. 2160/2003 of the European Parliament and of the Council of 17 November 2003 on the control of Salmonella and other specified food-borne zoonotic agents’, Official Journal of the European Union, 27.10.2007 ec (2005a), ‘Commission Regulation (EC) No 2073/2005 of 15 November 2005 on microbiological criteria for foodstuffs’, Official Journal of the European Union, 22.12.2005 ec (2005b), ‘Commission Regulation (EC) No 1003/2005 of 30 June 2005 implementing Regulation (EC) No 2160/2003 as regards a Community target for the reduction of the prevalence of certain Salmonella serotypes in breeding flocks of Gallus gallus and amending Regulation (EC) No 2160/2003’, Official Journal of the European Union, 1.07.2005 efsa (2007), ‘Community Summary Report on trends and sources of zoonoses, zoonotic agents, antimicrobial resistance and foodborne outbreaks in E.U. 2006’, The EFSA Journal, 130, 1–352. egorova s, timinouni m, demartin m, granier s a, whichard j m, sangal v l, fabre l, delauné a, pardos m, millemann y, espié e, achtman m, grimont p a d & weill f-x (2008), ‘Ceftriaxone-Resistant Salmonella enterica Serotype Newport, France’, Emerging Infectious Diseases, 14, 954–957. elder r o, keen j e, siragus g r, barkocy-gallagher g a, koohmaraie m & laegreid w w (2000), ‘Correlation of enterohemorrhagic Escherichia coli O157 prevalence in feces, hides, and carcasses of beef cattle during processing’, National Academy of Sciences, 97, 2999–3003. doi: 10.1073/pnas.060024897 eleftheriadou m, varnava-tello a, metta-loizidou m, nikolaou a-s & akkelidou d (2002), ‘The microbiological profile of foods in the Republic of Cyprus: 1991– 2000’, Food Microbiology, 19, 463–471. doi: 10.1006/yfmic.508 eriksson e, aspan a, gunnarsson a & vagsholm i (2005), ‘Prevalence of verotoxinproducing Escherichia coli (VTEC) O157 in Swedish dairy herds’, Epidemiology and Infection, 133, 349–358. doi: 10.1017/S0950268804003371 espié e (2003), ‘Outbreak of multidrug resistant Salmonella Newport due to the consumption of horsemeat in France’, Eurosurveillance, 7, available online: http:// www.eurosurveillance.org/ViewArticle.aspx?ArticleId=2252 ethelberg s, smith b, torpdahl m, lisby m, boel j, jensen t & mølbak k (2007a), ‘An outbreak of verocytotoxin-producing Escherichia coli O26:H11 caused by beef sausge, Denmark 2007’, Eurosurveillance, 12, available online: http://www. eurosurveillance.org/ViewArticle.aspx?ArticleId=3208 ethelberg s, sorensen g, kristensen b, christensen k, krusaell l, hempeljorgensen a, perge a & nielsen e m (2007b), ‘Outbreak with multi-resistant Salmonella Typhimurium DT104 linked to carpaccio, Denmark 2005’, Epidemiology and Infection, 135, 900–907. doi: 10.1017/S0950268807008047

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

97

faith n, parniere n, larson t, lorang t, kaspar c & luchansky j (1998), ‘Viability of Escherichia coli O157:H7 in salami following conditioning of batter, fermentation and drying of sticks, and storage of slices’, Journal of Food Protection, 61, 377–382. fda (2001), ‘Foodborne Pathogenic Microorganisms and Natural Toxins Handbook; Escherichia coli O157:H7’, United States Department of Health and Human Services. http://www.cfsan.fda.gov/~mow/chap15.html fda (2003), ‘Detection and Enumeration of Listeria monocytogenes in Foods’, Bacteriological Analytical Manual Online Chapter 10, United States Department of Health and Human Services. http://www.foodsafety.gov/~ebam/bam-10.html fda (2005), ‘Food Code’, United States Department of Health and Human Services. http://www.cfsan.fda.gov/~dms/fc05-toc.html fda (2007), ‘Salmonella’ Bacteriological Analytical Manual. Online Chapter 5, United States Department of Health and Human Services. http://www.cfsan.fda. gov/~ebam/bam-5.html fey p d, wickert r s, rupp m e, safranek t j & hinrichs s h (2000), ‘Prevalence of non-O157:H7 shiga toxin-producing Escherichia coli in diarrheal stool samples from Nebraska’, Emerging Infectious Diseases, 6, 530–533. fisher i s & meakins s (2006), ‘Surveillance of enteric pathogens in Europe and beyond: Enter-net annual report for 2004’, Eurosurveillance, 11, available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=3032 frenzen p d, riggs t l, buzby j c, breuer t, roberts t, voetsch d & reddy s (1999), ‘Salmonella cost estimate updated using FoodNet Data’, Food Review, 22, 10–15. fsai (food safety authority of ireland) (2002), ‘A surveillance study of E. coli O157:H7 and Enterobacteriaceae in Irish retail minced beef and beef burgers’, www.fsai.ie. fsai (food safety authority of ireland) (2009), ‘Control and management of verocytotoxigenic Escherichia coli (VTEC) along the farm to fork chain’, www. fsai.ie. fsis (1996), ‘Nationwide federal plant raw ground beef microbiological survey’ August 1993–March 1994’, US Department of Agriculture, Washington, DC. www. fsis.usda.gov/OPHS/baseline/rwgrbeef.pdf fsis (2002a), ‘FSIS adopts new screening method for Listeria monocytogenes’, US Department of Agriculture, Washington, DC. fsis (2002b), ‘E. coli O157:H7 contamination of beef products; 9 CFR Part 417, Docket No. 00–022N’, Federal Register, 67, 62325–62334. fsis (2003), ‘FSIS rule designed to reduce Listeria monocytogenes in Ready-to-eat meat and poultry products’, US Department of Agriculture, Washington, DC. fsis (2004), ‘FSIS Directive 10,010.1, microbiological testing program and other verification activities for Escherichia coli O157:H7 in raw ground beef products and raw ground beef components and beef patty components’, US Department of Agriculture, Washington, DC. fsis (2005), ‘FSIS ground beef sampling shows substantial E. coli O157:H7 decline in 2004’, US Department of Agriculture, Washington, DC. fsis (2006), ‘Salmonella verification sample result reporting: agency policy and use in public health protection, Docket No. 04-026N’, Federal Register, 71, 9772–9777. fsis (2008), ‘Progress report on Salmonella testing of raw meat and poultry products, 1998–2007’, US Department of Agriculture, Washington, DC. gasanov u, hughes d & hansbro p m (2005), ‘Methods for the isolation and identification of Listeria spp. and Listeria monocytogenes: a review’, FEMS Microbiology Reviews, 29, 851–875. doi: 10.1016/j.femsre.2004.12.002 gellin b g & broome c v (1989), ‘Listeriosis’, Journal of the American Medical Association, 261, 1313–1320.

© Woodhead Publishing Limited, 2011

98

Processed meats

gianfranceschi m v, gattuso a, d’ottavio m , fokas s & aureli p (2007), ‘Results of a 12-month long enhanced surveillance of listeriosis in Italy’, Eurosurveillance, 12, available online: http://www.eurosurveillance.org/ViewArticle.aspx? ArticleId=746 gillespie i (2005), ‘Successful reduction of human Salmonella Enteritidis infection in England and Wales’, Eurosurveillance, 10, available online: http://www. eurosurveillance.org/ViewArticle.aspx?ArticleId=2834 gillespie i a, mclauchlin j, grant k a, little c l, mithani v, penman c, lane c & regan m (2006), ‘Changing pattern of human listeriosis, England and Wales, 2001– 2004’, Emerging Infectious Diseases, 12, 1361–1366. giovannini a, prencipe v, conte a, marino l, petrini a, pomilio f, rizzi v & migliorati g (2004), ‘Quantitative risk assessment of Salmonella spp. Infection for the consumer of pork products in an Italian region’, Food Control, 15, 139–144. doi: 10.1016/S0956-7135(03)00025-2 glass k a & doyle m p (1989), ‘Fate of Listeria monocytogenes in processed meat products during refrigerated storage’, Applied and Environmental Microbiology, 55, 1565–1569. glass k a, loeffelholz j m, ford j p & doyle m p (1992), ‘Fate of Escherichia coli 0157:H7 as affected by pH or sodium chloride and in fermented, dry sausge’, Applied and Environmental Microbiology, 58, 2513–2516. glynn m k, bopp c, dewitt w, dabney p, mokhtar m & angulo f j (1998), ‘Emergence of multidrug-resistant Salmonella enterica serotype Typhimurium DT104 infections in the United States’, The New England Journal of Medicine, 338, 1333–1338. gomez-lopez a, coperias-zazo j l, diez-diaz r & ladron-deguevara c (2000), ‘Incidence of E. coli O157:H7 and other enteropathogens in a Spanish hospital’, European Journal of Epidemiology, 16, 303–304. gordon m a (2008), ‘Salmonella infections in immunocompromised adults’, Journal of Infection, 56, 413–422. doi: 10.1016/j.jinf.2008.03.012 gorman r & adley c c (2003), ‘Nalidixic acid-resistant strains of Salmonella showing decreased susceptibility to fluoroquinolones in the mid-west region of the Republic of Ireland’, Journal of Antimicrobial Chemotherapy, 51, 1047–1049. doi: 10.1093/ jac/dkg159 gottlieb s l, newbern e c, griffin p m, graves l m, hoekstra m, baker n l, hunter s b, holt k g, ramsey f, head m, levine p, johnson g, schoonmaker-bopp d, reddy v, kornstein l, gerwel m, nsubuga j, edwards l, stonecipher, s, hurd s, austin d, jefferson m a, young s d, hise k, chernak e d & sobel j (2006), ‘Multistate outbreak of listeriosis linked to turkey deli meat and subsequent changes in USA regulatory policy’, Clinical Infectious Diseases, 42, 29–36. griffin p m & tauxe r v (1991), ‘The epidemiology of infections caused by Escherichia coli O157: H7, other enterohemorrhagic E. coli, and the associated hemolytic uremic syndrome’, Epidemiologic Reviews, 13, 60–98. griffin p m, ostroff s m, tauxe r v, greene k d, wells j g, lewis j h & blake p a (1988), ‘Illnesses associated with Escherichia coli O157:H7 infections’, Annals of Internal Medicine, 109, 705–712. guerini m n, brichta-harhay d m, shackelford s d, arthur t m, bosilevac j m, kalchayanand n, wheeler t l & koohmaraie m (2007), ‘Listeria prevalence and Listeria monocytogenes serovar diversity at cull cow and bull processing plants in the United States’, Journal of Food Protection, 70, 2578–2582. haeghebaert s, duché l, gilles c, masini b, dubreuil m, minet j, bouvet p, grimont f, astagneau e d & vaillant v (2001), ‘Minced beef and human salmonellosis: review of the investigation of three outbreaks in France’, Eurosurveillance, 6, available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId =223

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

99

hara-kudo y, konishi n, ohtsuka k, hiramatsu r, tanaka h, konuma h & takatori k (2008), ‘Detection of verotoxigenic Escherichia coli O157 and O26 in food by plating methods and LAMP method: a collaborative study’, International Journal of Food Microbiology, 122, 156–161. doi: 10.1016/j.ijfoodmicro.2007.11. 078 helms m, ethelberg m s & mølbak k (2005), ‘International Salmonella Typhimurium DT104 infections, 1992–2001’, Emerging Infectious Diseases, 11, 859–867. hill c, o’driscoll b & booth i (1995), ‘Acid adaptation and food poisoning microorganisms’, International Journal of Food Microbiology, 28, 245–254. hjertqvist m, luzzi i, lofdahl s, olsson a, radal j & andersson y (2006), ‘Unusual phage pattern of Salmonella Typhimurium isolated from Swedish patients and Italian salami’, Eurosurveillance, 11, available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=2896 hohmann e l (2001), ‘Nontyphoidal salmonellosis’, Clinical Infectious Diseases, 32, 263–269. hpa (2006), ‘Sorbitol-fermenting Vero cytotoxin-producing E. coli O157 (VTEC O157)’, The Communicable Disease Report Weekly, 16, available online: http:// www.hpa.org.uk/cdr/archives/archive06/News/news2106.htm. hpa (2007), ‘Increased incidence of listeriosis in England and Wales, 2007’, Health Protection Report, 1, 3–4, available online: http://www.hpa.org.uk/hpr/archives/2007/ news2007/news2107.htm hpa (2008), ‘Detection of Salmonella species. National Standard Method F 13 Issue 3.1.’, available online: http://www.hpa-standardmethods.org.uk/pdf_sops.asp hpsc (2007), ‘Annual Report, 2006’, Health Service Executive, Health Protection Surveillance Centre, available online: http://www.ndsc.ie/hpsc/AboutHPSC/ AnnualReports/ hpsc (2008), ‘Annual Report, 2007’, Health Service Executive, Health Protection Surveillance Centre, available online: http://www.ndsc.ie/hpsc/AboutHPSC/ AnnualReports/ hpsc (2009), ‘Annual Report, 2008’, Health Service Executive, Health Protection Surveillance Centre, available online: http://www.hpsc.ie/hpsc/AboutHPSC/ AnnualReports/File,4080,en.pdf hughes c, gillespie i a & o’brien, s j (2007), ‘Foodborne transmission of infectious intestinal disease in England and Wales, 1992–2003’, Food Control, 18, 766–772. doi: 10.1016/j.foodcont.2006.01.009 inoue s, nakama a, arai y, kokubo y, maruyama t, saito a, yoshida t, terao m, yamamoto s & kumagaia s (2000), ‘Prevalence and contamination levels of Listeria monocytogenes in retail foods in Japan’, International Journal of Food Microbiology, 59, 73–77. invs (2000), ‘Outbreak of listeriosis linked to the consumption of rillettes in France’, Eurosurveillance, 4, available online: http://www.eurosurveillance.org/View Article.aspx?ArticleId=1674 isakbaeva e, lindstedt b-a, schimmer b, vardund t, stavnes t-l, hauge k, gondrosen b, blystad h, kløvstad h, aavitsland p, nygård k & kapperud g (2005), ‘Salmonella Typhimurium DT104 outbreak linked to imported minced beef, Norway, October November 2005’, Eurosurveillance, 10, available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=2829. iso (1998), ‘ISO 11290-2: Microbiology of food and animal feeding stuffs – Horizontal method for the detection and enumeration of Listeria monocytogenes – Part 2: Enumeration method’, ISO Standards, http://www.iso.org/iso/iso_ catalogue/catalogue_tc/catalogue_detail.htm?csnumber=25570. iso (2001), ‘ISO 16654:2001 Microbiology of food and animal feeding stuffs – Horizontal method for the detection of Escherichia coli O157’, http://www.iso.org/ iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=29821.

© Woodhead Publishing Limited, 2011

100

Processed meats

iso (2002), ‘ISO 6579:2002 Microbiology of food and animal feeding stuffs – Horizontal method for the detection of Salmonella spp. ISO Standards’, http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm? csnumber=29315. jemmi t & stephan r (2006), ‘Listeria monocytogenes: food-borne pathogen and hygiene indicator’, OIE Revue Scientifique et Technique, 25, 571–580. jones r c, reddy v, kornstein l, fernandez j r, stavinsky f, agasan a & gerber s i (2004), ‘Salmonella enterica serotype Uganda infection in New York City and Chicago’, Emerging Infectious Diseases, 10, 1665–1667. jordan e, egan j, duella c, ward j, mcgillicuddy k, murray g, murphy a, bradshaw b, leonard n, rafter p & mcdowell s (2006), ‘Salmonella surveillance in raw and cooked meat and meat products in the Republic of Ireland from 2002 to 2004’, International Journal of Food Microbiology, 112, 66–70. doi: 10.1016/j. ijfoodmicro.2006.05.013 karch h, bohm h, schmidt h, gunzer f, aleksic s & heesemann j (1993), ‘Clonal structure and pathogenicity of shiga-like toxin-producing, sorbitol-fermenting Escherichia coli O157:H−’, Journal of Clinical Microbiology, 31, 1200–1205. khaitsa m l, kegode r b & doetkott d k (2007), ‘Occurrence of antimicrobialresistant Salmonella species in raw and ready to eat turkey meat products from retail outlets in the Midwestern United States’, Foodborne Pathogens and Diseases, 4, 517–525. doi: 10.1089=fpd.2007.0010 kivi m, hofhuis a, notermans d w, b wannet w j, heck m e, giessen a w v d, duynhoven y t , stenvers o f, bosman a & pelt w v (2007), ‘A beef-associated outbreak of Salmonella Typhimurium DT104 in The Netherlands with implications for national and international policy’, Epidemiology and Infection, 135, 890–899. doi: 10.1017/S0950268807007972 koch j & stark k (2006), ‘Significant increase of listeriosis in Germany – epidemiological patterns 2001–2005’, Eurosurveillance, 11, available online: http://www. eurosurveillance.org/ViewArticle.aspx?ArticleId=631 koohmaraie m, arthur t m, bosilevac j m, brichta-harhay d m, kalchayanand n, shackelford s d & wheeler t l (2007), ‘Interventions to reduce/eliminate Escherichia coli O157:H7 in ground beef’, Meat Science, 77, 90–96. doi: 10.1016/j. meatsci.2007.04.004 laine e s, schefte j m, boxrud d j, vought k j, danila r n, elfering k m & smith k e (2005), ‘Outbreak of Escherichia coli O157:H7 infections associated with nonintact blade-tenderized frozen steaks sold by door-to-door vendors’, Journal of Food Protection, 68, 1198–1202. lianoua a, geornarasa i, kendallb p a, scangaa j a & sofos j n (2007), ‘Behavior of Listeria monocytogenes at 71 °C in commercial turkey breast, with or without antimicrobials, after simulated contamination for manufacturing, retail and consumer settings’, Food Microbiology, 24, 433–443. doi: 10.1016/j.fm.2006.11.002 little c l, richardson j f, owen r j, pinna e d & threlfall e j (2008), ‘Campylobacter and Salmonella in raw red meats in the United Kingdom: prevalence, characterization and antimicrobial resistance pattern, 2003–2005’, Food Microbiology, 25, 538–543. doi: 10.1016/j.fm.2008.01.001 lukinmaa s, miettinen m, nakari, u-m, korkeala h & siitonen a (2003), ‘Listeria monocytogenes isolates from invasive infections: variation of sero- and genotypes during an 11-year period in Finland’, Journal of Clinical Microbiology, 41, 1694– 1700. doi: 10.1128/JCM.41.4.1694–1700.2003 lundén j m, autio t j, sjoberg a-m & korkeala h j (2003), ‘Persistent and nonpersistent Listeria monocytogenes contamination in meat and poultry processing plants’, Journal of Food Protection, 66, 2062–2069. lundén j, tolvanen r & korkeala h (2004), ‘Human listeriosis outbreaks linked to dairy products in Europe’, Journal of Dairy Science, 87, E6–E11.

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

101

luzzi i, galetta p, massari m, rizzo c, dionisi a m, filetici e, cawthorne a, tozzi a, argentieri m, bilei s, busni l, gnesivo c, pendenza a, piccoli a, napoli p, loffredo r, trinito m o, santarelli e & ciofi degli atti m l (2007), ‘An easter outbreak of Salmonella Typhimurium DT 104A associated with traditional pork salami in Italy’, Eurosurveillance, 12, available online: http://www. eurosurveillance.org/ViewArticle.aspx?ArticleId=702 lynch m, painter j, woodruff r & braden c (2006), ‘Surveillance for foodbornedisease outbreaks – United States, 1998—2002’, Morbidity and Mortality Weekly Report (MMWR), 55, 1–34. macdonald d m, fyfe m, paccagnella a, trinidad a, louie k & patrick d (2003), ‘Escherichia coli O157:H7 outbreak linked to salami, British Columbia, Canada, 1999’, Epidemiology and Infection, 132, 283–289. march s b & ratnam s (1986), ‘Sorbitol-MacConkey medium for detection of Escherichia coli O157:H7 associated with hemorrhagic colitis’, Journal of Clinical Microbiology, 23, 869–872. march s b & ratnam s (1989), ‘Latex agglutination test for detection of Escherichia coli serotype O157’, Journal of Clinical Microbiology, 27, 1675–1677. mataragas m, skandamis p n & drosinos e h (2008), ‘Risk profiles of pork and poultry meat and risk ratings of various pathogen/product combinations’, International Journal of Food Microbiology, 126(1–2), 1–12. doi: 10.1016/j. ijfoodmicro.2008.05.014 mattick k l, bailey r a, jørgensen f & humphrey t j (2002), ‘The prevalence and number of Salmonella in sausages and their destruction by frying, grilling or barbecuing’, Journal of Applied Microbiology, 93, 541–547. mccormick k, han i y, acton j c, sheldon b w & dawson p l (2003), ‘D- and z-values for Listeria monocytogenes and Salmonella Typhimurium in packaged low-fat ready-to-eat turkey bologna subjected to a surface pasteurization treatment’, Poultry Science, 82, 1337–1342. mcevoy j m, doherty a m, sheridan j j, blair i s & mc dowell d a (2003), ‘The prevalence of Salmonella spp. in bovine faecal, rumen and carcass samples at a commercial abattoir’, Journal of Applied Microbiology, 94, 693–700. mclauchlin j & newton l (1995), ‘Human listeriosis in England, Wales and Northern Ireland: a changing pattern of infection’, in XII International Symposium on Problems of Listeriosis, Promaco Conventions Pty Ltd, Perth, Western Australia, 177–181 mcmaster c, wilshaw r e a, doherty g a, kinnear w & cheasty t (2001), ‘Verocytotoxin-producing Escherichia coli serovar O26:H11. Outbreak in an Irish creche’, European Journal of Clinical Microbiology & Infectious Diseases, 20, 430–432. mead p s, slutsker l, dietz v, mccaig l f, bresee j, shapiro c, griffin p m & tauxe r (1999), ‘Food-related illness and death in the United States’, Emerging Infectious Diseases, 5, 607–625. mead p s, dunne e f, graves l, wiedmann m, patrick m, hunter s, salehi e, mostashari f, craig a, mshar p, bannerman t, sauders b d, hayes p, dewitt w, sparling p, griffin p, morse d, slutsker l & swaminathan b (2006), ‘Nationwide outbreak of listeriosis due to contaminated meat’, Epidemiology and Infection, 134, 744–751. doi: 10.1017/S0950268805005376 meakins s, fisher i s t, berghold c, gerner-smidt p, tschäpe h, cormican m, luzzi i, schneider f, wannett w, coia j, echeita a & threlfall e j (2008), ‘Antimicrobial drug resistance in human nontyphoidal Salmonella isolates in Europe 2000– 2004, a report from the Enter-net International Surveillance Network’, Microbial Drug Resistance, 14, 31–35. doi: 10.1089=mdr.2008.0777 menaa c, almeidaa g, carneiroa l, teixeiraa p, hogga t & gibbsa p a (2004), ‘Incidence of Listeria monocytogenes in different food products commercialized in Portugal’, Food Microbiology, 21, 213–216. doi: 10.1016/S0740–0020(03)00057–1

© Woodhead Publishing Limited, 2011

102

Processed meats

mmwr (1993a), ‘Update: multistate outbreak of Escherichia coli O157:H7 Infections from hamburgers – Western United States, 1992–1993’, Morbidity and Mortality Weekly Report (MMWR), 42, 258–263, available online: http://www.cdc.gov/ mmwr/preview/mmwrhtml/00020219.htm. mmwr (1993b), ‘Escherichia coli O157:H7 outbreak at a summer camp – Virginia, 1994’, Morbidity and Mortality Weekly Report (MMWR), 44, 4–8, available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/00020219.htm. mmwr (1995a), ‘Escherichia coli O157:H7 outbreak linked to commercially distributed dry-cured salami – Washington and California, 1994’, Morbidity and Mortality Weekly Report (MMWR), 44, 1570–160, available online: http://www.cdc.gov/ mmwr/preview/mmwrhtml/00036467.htm. mmwr (1995b), ‘Outbreak of salmonellosis associated with beef jerky – New Mexico, 1995’, Morbidity and Mortality Weekly Report (MMWR), 44, 785–788, available online: http://www.cdc.gov/MMWR/PDF/wk/mm4442.pdf mmwr (1995c), ‘Community outbreak of hemolytic uremic syndrome attributable to Escherichia coli O111:NM – South Australia 1995’, Morbidity and Mortality Weekly Report (MMWR), 44, 550–551, available online: http://www.cdc.gov/ mmwr/preview/mmwrhtml/00038232.htm mmwr (2000), ‘Multistate outbreak of listeriosis – United States, 2000’, Morbidity and Mortality Weekly Report (MMWR), 49, 1129–1130, available online: http:// www.cdc.gov/mmwr/preview/mmwrhtml/mm4950a1.htm mmwr (2002a), ‘Multistate outbreak of Escherichia coli O157:H7 infections associated with eating ground beef – United States, June–July 2002’, Morbidity and Mortality Weekly Report (MMWR), 51, 637–639, available online: http://www.cdc. gov/mmwr/preview/mmwrhtml/mm5129a1.htm mmwr (2002b), ‘Outbreak of multidrug-resistant Salmonella Newport – United States, January–April 2002’, Morbidity and Mortality Weekly Report (MMWR), 51, 545–548, available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/ mm5125a1.htm mmwr (2006), ‘Multistate outbreak of Salmonella Typhimurium infections associated with eating ground beef – United States, 2004’, Morbidity and Mortality Weekly Report (MMWR), 55, 180–182, available online: http://www.cdc.gov/mmwr/ preview/mmwrhtml/mm5507a4.htm mmwr (2007), ‘Laboratory-confirmed Non-O157 shiga toxin-producing Escherichia coli – Connecticut, 2000–2005’, Morbidity and Mortality Weekly Report (MMWR), 56, 29–31, available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/ mm5602a2.htm mmwr (2008), ‘Preliminary FoodNet data on the incidence of infection with pathogens transmitted commonly through food – 10 States, 2007’, Morbidity and Mortality Weekly Report (MMWR), 57(14), 366–370, available online: http://www.cdc. gov/mmwr/preview/mmwrhtml/mm5714a2.htm molnar c, wels r & adley c c (2006), ‘A review of surveillance networks of foodborne diseases’, in Adley C C, Food-Borne Pathogens, Methods and Protocols, Humana Press, Totowa, NJ, 251–258. mossong j, marques p, ragimbeau c, huberty-krau p, losch s, meyer g, moris g, strottner c, rabsch w & schneider f (2007), ‘Outbreaks of monophasic Salmonella enterica serovar 4,[5],12:i:- in Luxembourg, 2006’, Eurosurveillance, 12, available online: http://www.eurosurveillance.org/viewarticle.aspx?articleid=719 mürmann l, santos m c d & cardoso m (2008), ‘Prevalence, genetic characterization and antimicrobial resistance of Salmonella isolated from fresh pork sausges in Porto Alegre, Brazil’, Food Control, 20, 191–195. doi: 10.1016/j.foodcont. 2008.04.007 murphy m, carroll a, whyte p, o’mahony m, anderson w, mcnamara e & fanning s (2005), ‘Prevalence and characterization of Escherichia coli O26 and O111 in

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

103

retail minced beef in Ireland’, Foodborne Pathogens and Diseases, 2, 357–360. doi: 10.1089/fpd.2005.2.357 murray e g d, webb r a & swann r a (1926), ‘A disease of rabbits characterised by a large mononuclear leucocytes, caused by a hitherto undescribed bacillus Bacterium monocytogenes (n.sp.)’, Journal of Pathology and Bacteriology, 29, 407–439. nishikawa y, ogasawara j, helander a & haruki k (1999), ‘An outbreak of gastroenteritis in Japan due to Escherichia coli O166’, Emerging Infectious Diseases, 5, p 300. noël h, dominiguez m, weill f x, duchazeaubeneix c, kerouanton a, delmas g, pihier n & couturier e (2006), ‘Outbreak of Salmonella enterica Manhattan infection associated with meat products, France, 2005’, Eurosurveillance, 11, 270– 273, available online: http://www.eurosurveillance.org/ViewArticle.aspx? ArticleId=660 nørrung b (2000), ‘Microbiological criteria for Listeria monocytogenes in foods under special consideration of risk assessment approaches’, International Journal of Food Microbiology, 62, 217–221. nørrung b, andersen j k & schlundt j (1999), ‘Incidence and control of Listeria monocytogenes in foods in Denmark’, International Journal of Food Microbiology, 53, 195–203. norwood d e & gilmour a (2000), ‘The growth and resistance to sodium hypochlorite of Listeria monocytogenes in a steady-state multispecies biofilm’, Journal of Applied Microbiology, 88, 512–520. nou x, rivera-betancourt m, bosilevac j m, wheeler t l, shackelford s d, gwartney b l, reagan j o & koohmaraie m (2003), ‘Effect of chemical dehairing on the prevalence of Escherichia coli O157:H7 and the levels of aerobic bacteria and Enterobacteriaceae on carcasses in a commercial beef processing plant’, Journal of Food Protection, 66, 2005–2009. nygård k, lindstedt b-a, wahl e, jensvoll l, kjelso c, molbak k, torpdahl m & kapperud g (2007), ‘Outbreak of Salmonella Typhimurium infection traced to imported cured sasage using MLVA-subtyping’, Eurosurveillance, 12, available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=3158 o’flanagan d, cormican m, mckeown p, nicolay n, cowden j, mason b, morgan d, lane c, irvine n & browning l (2008), ‘A multi-country outbreak of Salmonella Agona, February–August 2008’, Eurosurveillance, 13, available online: http://www. eurosurveillance.org/ViewArticle.aspx?ArticleId=18956 o’hanlon k a, catarame t m g, blair i s, mcdowell d a & duffy g (2005), ‘Comparison of a real-time PCR and an IMS/culture method to detect Escherichia coli O26 and O111 in minced beef in the Republic of Ireland’, Food Microbiology, 22, 553–560. doi: 10.1016/j.fm.2004.11.012 oteiza j m, chinenb i, miliwebskyb e & rivas m (2006), ‘Isolation and characterization of Shiga toxin-producing Escherichia coli from precooked sausges (morcillas)’, Food Microbiology, 23, 283–288. doi: 10.1016/j.fm.2005.04.003 pak s-i, spahr u, jemmi t & salman m d (2002), ‘Risk factors for L. monocytogenes contamination of dairy products in Switzerland, 1990–1999’, Preventive Veterinary Medicine, 53, 55–65. pal a, labuza t p & diez-gonzalez f (2008), ‘Shelf life evaluation for ready-to-eat sliced uncured turkey breast and cured ham under probable storage conditions based on Listeria monocytogenes and psychrotroph growth’, International Journal of Food Microbiology, 126, 49–56. doi: 10.1016/j.ijfoodmicro.2008.04.028 patrina j, antonenko i & perevoscikovas j (2006), ‘Outbreak of Salmonella Enteritidis infections in people attending a village event in Latvia’, Eurosurveillance, 11, 195–196, available online: http://www.eurosurveillance.org/ViewArticle. aspx?ArticleId=3026

© Woodhead Publishing Limited, 2011

104

Processed meats

peccio a, autio t, korkeala h, rosmini r & trevisani m (2003), ‘Listeria monocytogenes occurrence and characterization in meat-producing plants’, Letters in Applied Microbiology, 37, 234–238. doi: 10.1046/j.1472–765X.2003.01384.x pennington h (1998), ‘Factors involved in recent outbreaks of Escherichia coli O157:H7 in Scotland and recommendations for its control’, Journal of Food Safety, 18, 383–391. phac (public health agency of canada) (2008), ‘Listeria monocytogenes outbreak’, available online: http://www.phac-aspc.gc.ca/alert-alerte/listeria_200808-eng.php phan-thanh l, mahouin f & alige s (2000), ‘Acid responses of Listeria monocytogenes’, International Journal of Food Microbiology, 55, 121–126. piddock l v j (2002), ‘Fluoroquinolone resistance in Salmonella serovars isolated from humans and food animals’, FEMS Microbiology Reviews, 26, 3–16. pollock k (2005), ‘Enhanced surveillance of haemolytic uraemic syndrome and other thrombotic microangiopathies in Scotland, 2003–2004’, Eurosurveillance, 10, available online: http://www.eurosurveillance.org/ViewArticle. aspx?ArticleId=2708 pontello m, sodano l, nastasi a, mammina c, astuti m, domenichini m, belluzzi g, soccini e, silvestri m g, gatti m, gerosa e & montagna a (1998), ‘A community based outbreak of Salmonella enterica serotype Typhimurium associated with salami consumption in Northern Italy’, Epidemiology and Infection, 120, 209–214. pritchard t j, flanders k j & donnelly c w (1995), ‘Comparison of the incidence of Listeria on equipment versus environmental sites within dairy processing plants’, International Journal of Food Microbiology, 26, 375–384. qvist s (2007), ‘Nordval: A system for validation of alternative microbiological methods’, Food Control, 18, 113–117. doi: 10.1016/j.foodcont.2005.09.001 rangel j m, sparling p h, crowe c, griffin p m & swerdlow d l (2005), ‘Epidemiology of Escherichia coli O157:H7 Outbreaks, United States, 1982–2002’, Emerging Infectious Diseases, 11, 603–609. ratnam s, march s b, ahmed r, bezanson g s & kasatiya s (1988), ‘Characterization of Escherichia coli serotype O157:H7’, Journal of Clinical Microbiology, 26, 2006–2012. riley l w, remis r s & helgerson s d (1983), ‘Haemorrhagic colitis associated with a rare Escherichia coli serotype’, New England Journal of Medicine, 308, 681–685. roels t h, frazak p a, kazmierczak j j, mackenzie w r, proctor m e, kurzynski t a & davis j p (1997), ‘Incomplete sanitation of a meat grinder and ingestion of raw ground beef: contributing factors to a large outbreak of Salmonella Typhimurium infection’, Epidemiology and Infection, 119, 127–134. rowan n j (2004), ‘Viable but not culturable forms of food and waterborne bacteria: quo vadis?’, Trends in Food Science & Technology, 15, 462–467. doi: 10.1016/j. tifs.2004.02.009 rowan n j & anderson j g (1998), ‘Effects of above-optimum growth temperature and cell morphology on thermotolerance of Listeria monocytogenes cells suspended in bovine milk’, Applied and Environmental Microbiology, 64, 2065–2071. salmon r (2005), ‘Outbreak of verotoxin producing E. coli O157 infections involving over forty schools in south Wales, September 2005’, Eurosurveillance 10, available online: http://www.eurosurveillance.org/viewarticle.aspx?articleid=2804 samelis j & metaxopoulos j (1999), ‘Incidence and principal sources of Listeria spp. and Listeria monocytogenes contamination in processed meats and a meat processing plant’, Food Microbiology, 16, 465–477. sartz l, jong b d, hjertqvist m, plym-forshell l, alsterlund r, lofdahl s, osterman b, stahl a, eriksson e, hansson h-b & karpman d (2008), ‘An outbreak of

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

105

Escherichia coli O157:H7 infection in southern Sweden associated with consumption of fermented sausge; aspects of sausge production that increase the risk of contamination’, Epidemiology and Infection, 136, 370–380. doi: 10.1017/ S0950268807008473 schimmer b, nygard k, eriksen h-m, lassen j, lindstedt b-a, brandal l t, kapperud g & aavitsland p (2008), ‘Outbreak of haemolytic uraemic syndrome in Norway caused by stx2-positive Escherichia coli O103:H25 traced to cured mutton sausges’, BMC Infectious Diseases, 8. doi: 10.1186/1471-2334-841 scotter s l, langton s, lombard b, schulten s, nagelkerke n, in‘t velde p h, rollier p & lahellec c (2001), ‘Validation of ISO method 11290 Part 1: Detection of Listeria monocytogenes in foods’, International Journal of Food Microbiology, 64, 295–306. scvmph (2003), ‘Verotoxigenic E. coli (VTEC) in foodstuffs, adopted on 21–22 January 2003’, Scientific Committee on Veterinary Measures relating to Public Health, available online http://ec.europa.eu/food/fs/sc/scv/out58_en.pdf. shank f r, elliot e l, wachsmuth i k & losikoff m e (1996), ‘USA position on Listeria monocytogenes in foods’, Food Control, 7, 229–234. shazberg g, wolk m, schmidt h, sechter i, gottesman g & miron d (2003), ‘Enteroaggregative Escherichia coli serotype O126:H27, Israel’, Emerging Infectious Diseases, 9, 1170–1173. smerdon w j, adak g k, o’brien s j, gillespie i a & reacher m (2001), ‘General outbreaks of infectious intestinal disease linked with red meat, England and Wales, 1992–1999’, Communicable Disease Public Health, 4, 259–267. sofos j n (2008), ‘Challenges to meat safety in the 21st century’, Meat Science, 78, 3–13. doi: 10.1016/j.meatsci.2007.07.027 stirling a, mccartney g, ahmed s & cowden j (2007), ‘An outbreak of Escherichia coli O157 phage type 2 infection in Paisley, Scotland’, Eurosurveillance, 12, available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=3253 strockbine n a, marques l r m, newland n j w, smith h w, holmes r k & o’brien a d (1986), ‘Two toxin-converting phages from Escherichia coli O157:H7 strain 933 encode antigenically distinct toxins with similar biologic activities’, Infection and Immunity, 53, 135–140. tappero j w, schuchat a, deaver k a, mascola l & wenger j d (1995), ‘Reduction in the incidence of human listeriosis in the United States. Effectiveness of prevention efforts?’, The Journal of the American Medical Association, 273, 1118–1122. taylor p, allison l, willshaw g a, cheasty t & hanson m f (2003), ‘Sorbitol-fermenting Escherichia coli O157 in Scotland’, in Proceedings of the Fifth International Symposium on Shiga Toxin (Verocytotoxin) Producing Escherichia coli., June, Edinburgh, abstract, p280. teagasc (2005), ‘E. coli O157:H7 in beefburgers produced in the Republic of Ireland: a quantitative microbial risk assessment’, Food Production Series No. 74 Project No. 5035, www.teagasc.ie. threlfall e j (2002), ‘Antimicrobial drug resistance in Salmonella: problems and perspectives in food-and water-borne infections, ‘FEMS Microbiology Reviews, 26, 141–148. threlfall e j, frost j a, ward l r & rowe b (1996), ‘Increasing spectrum in multiresistant Salmonella Typhimurium’, The Lancet, 347, 1053–1054. threlfall e j, ward l r & rowe b (1997), ‘Increasing incidence of resistance to trimethoprim and ciprofloxacin in epidemic Salmonella Typhimurium DT104 in England and Wales’, Eurosurveillance, 2, 81–84, available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=187 threlfall e j, day m, pinna e d, charlett a & goodyear k l (2006), ‘Assessment of factors contributing to changes in the incidence of antimicrobial resistance in Salmonella enterica serotypes Enteritidis and Typhimurium from humans in

© Woodhead Publishing Limited, 2011

106

Processed meats

England and Wales in 2000, 20002 and 2004’, International Journal of Antimicrobial Agents, 28, 389–395, doi: 10.1016/j.ijantimicag.2006.07.009 tilden j, young w, mcnamara a-m, cusater c, boesel b, lambert-fair m a, majkowski j, vugia d, werner s b, hollingsworth j & morris j g (1996), ‘A new route of transmission for Escherichia coli: infection from dry fermented salami’, American Journal of Public Health, 86, 1142–1145. tompkin r b (2002), ‘Control of Listeria monocytogenes in the food-processing environment’, Journal of Food Protection, 65, 709–725. torpdahl m, sorensen g, ethelberg s, sando g, gammelgard k & porsbo l j (2006), ‘A regional outbreak of S. Typhimurium in Denmark and identification of the source using MLVA typing’, Eurosurveillance, 11, 134–136, available online http:// www.eurosurveillance.org/ViewArticle.aspx?ArticleId=621 tozzi a e, caprioli a, minelli f, gianviti a, petris l d, edefonti a, montini g, ferretti a, palo t d, gaido m & rizzoni g (2003), ‘Shiga toxin–producing Escherichia coli infections associated with hemolytic uremic syndrome, Italy, 1988–2000’, Emerging Infectious Diseases, 9, 106–108. tuttle j, gomez t, doyle m p, wells j g, zhao t, tauxe r v & griffin p m (1999), ‘Lessons from a large outbreak of Escherichia coli O157:H7 infections: insights into the infectious dose and method of widespread contamination of hamburger patties’, Epidemiology and Infection, 122, 185–192. ulukanli z, çavli p & tuzcu m (2006), ‘Detection of Escherichia coli O157:H7 from beef doner kebabs sold in Kars’, G.U. Journal of Science, 19, 99–104. velusmy v, arshak k, korostynska o, oliwa k & adley c c (2009), ‘Design of a real time biorecognition system to detect foodborne pathogens-DNA Biosensor’, IEEE Sensors Application Symposium, New Orleans; 17–19, February 2009 (SAS 2009): 38–42 10.1109/SAS.2009.4801773. vitas a i, aguado v & garcia-jalon i (2004), ‘Occurrence of Listeria monocytogenes in fresh and processed foods in Navarra (Spain)’, International Journal of Food Microbiology, 90, 349–356. doi: 10.1016/S0168-1605(03)00314-3 voetsch a c, gilder t j v, angulo f j, farley m m, shallow s, marcus r, cieslak p r, deneen v c & tauxe r v (2004), ‘FoodNet estimate of the burden of illness caused by nontyphoidal Salmonella infections in the United States’, Clinical and Infectious Diseases, 38, 127–134. voetsch a c, angulo f j, jones t f, moore m r, nadon c, mccarthy p, shiferaw b, megginson m b, hurd s, anderson b j, cronquist a, vugia d j, medusa c, segler s, graves l m, hoekstra r m & griffin p m (2007), ‘Reduction in the incidence of invasive listeriosis in foodborne diseases active surveillance network sites, 1996– 2003’, Clinical Infectious Diseases, 44, 513–520. wall p g, morgan d, lamden k, ryan m, griffin m, threlfall e j, ward l r & rowe b (1994), ‘A case control study of infection with an epidemic strain of multiresistant Salmonella Typhimurium DT104 in England and Wales’, Communicable Disease Report Review, 4, 130–135. wang g, zhao t & doyle m p (1996), ‘Fate of enterohemorrhagic Escherichia coli O157:H7 in bovine feces’, Applied and Environmental Microbiology, 62, 2567–2570. wells j g, davis b r, wachsmuth k, riley l w, remis r s, sokolow r & morris g k (1983), ‘Laboratory investigation of hemorrhagic colitis outbreaks associated with a rare Escherichia coli serotype’, Journal of Clinical Microbiology, 18, 512–520. wells j g, shipman l d, greene k d, sowers e g, green j h, cameron d n, downes f p, martin m l, griffin p m, ostroff s m, potter, m e, tauxe r v & wachsmuth i k (1991), ‘Isolation of Escherichia coli serotype O157:H7 and other Shiga-liketoxin-producing E. coli from dairy cattle’, Journal of Clinical Microbiology, 29, 985–989.

© Woodhead Publishing Limited, 2011

Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli

107

werber d, fruth a, liesegang a, littmann m, buchholz u, prager r, karch h, breuer t, tschape h & ammon a (2002), ‘A multistate outbreak of Shiga toxinproducing Escherichia coli O26:H11 infections in Germany, detected by molecular subtyping surveillance’, Journal of Infectious Diseases, 186, 419–422. white d g, zhao s, sudler r, ayers s, friedman s, chen s, mcdermott p f, mcdermott s, wagner d d & meng j (2001), ‘The isolation of antibiotic-resistant Salmonella from retail ground meats’, New England Journal of Medicine, 345, 1147–1154. williams r c, isaacs s, decou m l, richardson e a, buffett m c, slinger r w, brodsky m h, ciebin b w, ellis a & hockin, j (2000), ‘Illness outbreak associated with Escherichia coli O157:H7 in Genoa salami’, Canadian Medical Association, 162, 1409–1413. xu h s, roberts n, singleton f l, attwell r w, grimes d j and colwell r r (1982), ‘Survival and viability of nonculturable E. coli and V. cholerae in the estuarine and marine environment’, Microbial Ecology, 8, 313–323. zhao c, ge b, villena j d, sudler r, yeh e, zhao s, white d g, wagner d & meng j (2001), ‘Prevalance of Campylobacter spp., Escherichia coli, and Salmonella serovars in retail chicken, turkey, pork, and beef from the Greater Washington, D.C., area’, Applied and Environmental Microbiology, 67, 5431–5436. doi: 10.1128/ AEM.67.12.5431–5436.2001 zhao s, qaiyumi s, friedman s, singh r, foley s l, white d g, mc dermott p f, donkar t, bolin c, munro s, baron e j & walker r d (2003), ‘Characterization of Salmonella enterica serotype Newport isolated from humans and food animals’, Journal of Clinical Microbiology, 41, 5366–5371. doi: 10.1128/jcm.41.12.5366-5371.2003 zhao s, mc dermott p f, friedman s, abbott j, ayers s, glenn a, hall-robinson e, hubert s k, harbottle h, walker r d, chiller t m & white d g (2006), ‘Antimicrobial resistance and genetic relatedness among Salmonella from retail foods of animal origin: NARMS retail meat surveillance’, Foodborne Pathogens and Diseases, 3, 106–117. ziese t, anderson y, jong b d, löfdahl s & ramberg m (1996), ‘Outbreak of Escherichia coli O157 in Sweden’, Eurosurveillance, 1, available online: http://www. eurosurveillance.org/ViewArticle.aspx?ArticleId=135

4.7 Appendix: glossary Aw AFNOR AMI AOAC BAM BGA BS CAC CDC CFU ECDC EFSA EHEC EU FAO

Water activity Association Française de Normalisation American Meat Industry American Association of Analytical Communities Bacteriological Analytical Manual Brilliant Green agar Bismuth sulfite agar Codex Alimentarius Commission Centers for Disease Control and Prevention Colony forming units European Centre for Disease Prevention and Control European Food Safety Authority Enterohaemoharrogic E. coli European Union Food and Agriculture Organization

© Woodhead Publishing Limited, 2011

108

Processed meats

FDA FSAI FSIS HACCP HC HE HPSC HSPC INVS ISO LAMP NDSS NordVal PCR PHAC RTE RV UN USA USDA VBNC VTEC WHO XLD

Food and Drug Administration Food Safety Authority of Ireland Food Safety and Inspection Services Hazard Analysis and Critical Control Poin Hemorrhagic colitis Hektoen enteric agar Health Protection Surveillance Centre Heath Service Protection Centre Institute de Veille Sanitaire International Organization for Standardization Loop-mediated amplification assay Notifiable Diseases Surveillance System National Veterinary Institute, Norway Polymerase chain reaction Public Health Agency Canada Ready-to-eat Rappaport-Vassiliadis medium United Nations United States US Department of Agriculture Viable but non culturable Verocytotoxigenic E. coli World Health Organization Xylose Lysine Desoxycholae agar

© Woodhead Publishing Limited, 2011

5 The use of irradiation in processed meat products E. J. Lee, Iowa State University, USA and D. U. Ahn, Iowa State University, USA and Seoul National University, South Korea

Abstract: Irradiation is the best known method for controlling pathogens in meat products. However, the use of irradiation in meat is highly limited because of its effects on meat quality. Irradiation increases the amount of volatiles and produces new volatile compounds that influence sensory characteristics of irradiated meat. Various factors such as irradiation dose, oxygen, muscle type, additives, and packaging affect color and lipid oxidation in irradiated meat. To implement irradiation technology by the meat industry, developing prevention methods for quality changes in irradiated meat, especially further processed ready-to-eat meat products, is very important. This chapter discusses current knowledge on control of pathogens in processed meat, effects of irradiation on meat quality, and prevention of quality changes in irradiated processed meat. Key words: irradiation, meat, off-odor, color, lipid oxidation, packaging, antioxidants, processed meat, Listeria monocytogenes, prevention of quality changes, sensory characteristics, volatiles.

5.1 Introduction Foodborne illness has been a serious public-health problem in the United States and the total economic impact of foodborne illness across the nation is estimated to be $152 billion annually (Scharff, 2010). Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, Clostridium botulinum/ perfringens, Staphylococcus aureus and L. monocytogenes are some of the most frequently encountered pathogens causing foodborne illnesses, especially in processed meats (Mead et al., 1999). The elimination of L. monocytogenes from ready-to-eat (RTE) meat products is a particular challenge (Beresford et al., 2001) because it is widely present within the environment (Farber and Peterkin, 1991), can grow over wide temperature and pH

© Woodhead Publishing Limited, 2011

110

Processed meats

ranges (Ralovich, 1992; Seelinger and Jones, 1986) and can tolerate salt and nitrite (McClure et al., 1997). Additionally, RTE meat products are regularly consumed without further heating and are expected to have considerably long shelf-lives. Over the last 10 years or so, several serious disease outbreaks relating to L. monocytogenes have been reported and associated with the consumption of RTE meats (CDC, 1999, 2000, 2002). Consequently, the US Department of Agriculture (USDA) initiated a ‘zero tolerance’ policy to prohibit the sale of RTE meat products contaminated with L. monocytogenes (FSIS, 2003). Various pre-harvest and post-harvest intervention strategies to reduce or eliminate pathogens in meat products have been established in the US (Ahn et al., 2006). Among the post-harvest intervention methods, ionizing irradiation has been considered as one of the most promising technologies for eliminating foodborne pathogens from meat products (Andrews et al., 1998). Accelerated electrons, gamma-ray, and X-rays are used as sources for ionizing radiation because they have short wavelengths (<300 nm) and high energy, which create ions or free radicals from atoms (CAST, 1989). These free radicals can fragment or destroy the DNA of microorganisms and, consequently, can kill pathogens present in meat products. Gamma irradiation uses high-energy gamma rays from cobalt 60 or cesium 137, which has a long half-life and high penetration power. Therefore, gamma irradiation can treat bulk foods on shipping pallets. Electron beam irradiation is used to treat thin layers of a particular food product because a stream of high-energy electrons generated from an e-beam machine penetrates only several centimeters into the food. X-irradiation has intermediate properties of the two irradiation methods discussed above (Sadler et al., 2001). The advantages of using irradiation technology in foods include the fact that toxic chemicals in foods to kill pathogens are not required and that cross-contamination of food products during post-processing handling can be prevented because food products are treated after final packaging. Irradiation technology is regarded as one of the safest food processing techniques available today as it has a long history which has been successfully underpinned by sound scientific research, including thorough toxicological and microbiological evaluations before gaining approval for application and usage with food products (AMA, 1993; WHO, 1994). Currently, 57 countries approve the use of food irradiation and more than half a million tons of food are irradiated annually in the world (IAEA, 1999; Kume et al., 2009). In the US, spices and seasonings, fresh fruits, and dry substances (USDA FSIS, 1986), poultry (USDA FSIS, 1992), red meats (USDA FSIS, 1999a), shell eggs (FDA, 2000), mollusks (FDA, 2005), and other fresh produces such as iceberg lettuce and spinach (FDA, 2008) are approved for irradiation (Table 5.1). A petition for irradiating processed meats was filed in 1999, but to date has not yet been approved by the Food and Drug Administration (FDA).

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

111

Table 5.1 Approval of food irradiation in the US Approval date

Products

1964, 1965 1983

0.05–0.15 <30

1985

Potatoes Spices and dry seasonings Pork

1985, 1986

Dehydrated enzymes

<10

1986

<1

1997, 1999

Fruits and vegetables Herb, spices and seasonings Poultry, fresh and frozen Meat, frozen and packaged Red meat, chilled

2000 2000

Red meat, frozen Shell eggs Sprouts

<7.5 <3.0 <8.0

2005

Fresh or frozen molluscan shellfish

<5.5

2008

Iceberg lettuce and spinach

<4.0

1986 1990 1995

Dose (kGy)

0.3–1.0

<30 <3.0 >44 <4.5

Purpose Inhibit sprouting Disinfestation and decontamination Control of Trachinella spiralis Control insects and micobes Delay maturation and disinfection Control of microorganisms Control of microorganisms Sterilization only for NASA Control of microorganisms Control of S. Enteriditis Control of pathogens in seeds Control of Vibrio species and other foodborne pathogens Control of foodborne pathogens and extension of shelf-life

5.2 Control of pathogens in processed meat products Although ready-to-eat (RTE) meat products are the most popular meat products in the US, RTE meat products are major sources of listeriosis, mostly due to post-processing contamination. Zhu et al. (2005a) reported that whole cooked meat products (e.g. cooked ham, bacon) after slicing have higher listeriosis incidence rates than equivalent products before slicing, indicating post-processing contamination during slicing and repackaging. Listeriosis annually accounts for about 2500 cases of food poisoning and around $200 million in losses because of its associated high mortality rate (∼25%), especially among the elderly and infant populations (Mead et al., 1999) along with other negative economic impacts arising from product recall, loss of productivity and human medical bills (FSIS, 2003). L. monocytogenes is a Gram-positive, non-sporeforming, highly mobile, rod-type, facultative anaerobic bacterium (Farber and Peterkin, 1991), which is ubiquitously found in processing environments, including plant, soil, sewage, slaughterhouse waste, human and animal feces (Autio et al.,

© Woodhead Publishing Limited, 2011

112

Processed meats

2000; Gillespie et al., 2000; Beresford et al., 2001). The organism has high temperature, salt and (Ralovich, 1992) pH tolerances (Seelinger and Jones, 1986) and can even grow in cured meat products during refrigerated storage (McClure et al., 1997). Therefore, both the prevention and elimination of L. monocytogenes contamination in processed meats are critically important in order to improve the safety of such products (Zhu et al., 2005a). Raw meat contaminated with L. monocytogenes can be easily dealt with and controlled during cooking of this material for the manufacture of RTE meat products because heating is highly effective in destroying L. monocytogene. Shamsuzzaman et al. (1995) reported that the combination of heating and e-beam irradiation was very effective in eliminating inoculated L. monocytogenes in chicken breast meat. However, elimination of L. monocytogenes from contaminated RTE meats post-packaging is not as easy and straightforward to control. In-package thermal pasteurization and irradiation and the formulation of meat products with antimicrobial additives are common approaches used to control L. monocytogenes in RTE meats postpackaging (Fu et al., 1995a; Thayer and Boyd, 2000; Bedie et al., 2001; Muriana et al., 2002; Samelis et al., 2002; Foong et al., 2004). In-package thermal pasteurization process is generally effective in reducing or eliminating contaminated L. monocytogenes cells in low fat turkey bologna (McCormick et al., 2003), but product shrinkage and drip loss during the post-package thermal pasteurization process can cause quality issues in post-package products. The effectiveness of in-package pasteurization in inactivating pathogenic organisms depends on package size (Murphy et al., 2003a), packaging materials used, processing temperature and time, pH characteristics, product surface characteristics (Murphy et al., 2003b) and L. monocytogenes strains present (Lemaire et al., 1989). The elimination of microorganisms in RTE meat by irradiation can vary depending upon several factors, such as irradiation dose, meat composition, temperature, gaseous atmosphere and microbial factors (Olson, 1998b; Sommers et al., 2002a) (Table 5.2). High dose radiation is effective in eliminating large numbers of pathogenic microorganisms, but impacts negatively on numerous meat quality attributes. E-beam was more effective than gamma-ray irradiation in reducing numbers of Bacillus cereus and E. coli Table 5.2

Shelf-lives of meat products after irradiation

Meat products

Dose (kGy)

Beef top round Beefburgers Beef cuts under vacuum Corned beef Whole and minced lamb

2 1.54 2 4 2.5

Untreated shelf-life (days)

Irradiated shelf-life (days)

8–11 8–10 NA 14–21 7

28 26–28 70 35 28–35

Source: Adapted from Andrews et al. (1998), Rev Environ Contam Toxicol, 154, 1–53.

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

113

O157:H7, but were similarly effective for L. monocytogenes (Miyahara, 2002). Fu et al. (1995a) reported that a low dose e-beam irradiation (0.75 to 0.90 kGy) reduced L. monocytogenes by more than 2-log in cooked pork chops and hams. Foong et al. (2004) reported that 1.5 kGy e-beam irradiation is required to accomplish a 3-log reduction of L. monocytogenes for bologna, roast beef and turkey both with and without lactate, and 2.0 kGy for frankfurters and ham. Cabeza et al. (2009) reported that irradiation at 1.29 kGy satisfied the ‘zero tolerance’ criterion for Listeria innocua NTC 11288, Salmonella Enteritidis and S. Typhimurium in RTE dry fermented sausages. Cabeza et al. (2007) reported that e-beam irradiation of RTE cooked ham using <2.0 kGy was an effective treatment to meet the food safety objective (FSO) set by EU and USDA criteria without negatively modifying the sensory properties of products (appearance, odor and flavor). The presence of high levels of antioxidants in meat can decrease the antimicrobial efficacy of ionizing radiation because they neutralize free radicals before free radicals attack the DNA of microorganisms (Diehl, 1995; Steccheni et al., 1998). Salt content in products also affects the effectiveness of irradiation in killing pathogenic organisms. Thayer et al. (1995) reported that the survival of Salmonella typhimurium in irradiated mechanically deboned chicken meat and ground pork loin was greatly increased by increasing NaCl concentrations and decreasing water content in the products because chloride ions scavenged hydroxyl radicals and the decreased availability of extracellular water resulted in decreased production of free radicals to kill the bacteria. The presence of added citric acid in frankfurters enhanced the lethality of ionizing radiation while dextrose concentration did not affect the radiation resistance of L. monocytogenes in bologna slices (Sommers and Fan, 2002b). The presence of oxygen increased the microcidal effect of irradiation in meat (Fu et al., 1995b; Thayer and Boyd, 1999). The microcidal effect of irradiation can also vary depending upon numerous microbial factors, including numbers, types and physiological status of microorganisms in meat (Table 5.3). Viruses have the highest resistance to Table 5.3

D-values of foodborne pathogens

Pathogen

Approximated D-values (kGy)

C. jejuni C. perfringens E. coli O157 : H7 L. monocytogenes Salmonella spp. S. aureus Toxoplasma gondii Trichinella spiralis

0.18 0.586 0.25 0.4–0.64 0.48–0.7 0.45 0.4–0.7 0.3–0.6

Adopted from USDA FSIS (1999b).

© Woodhead Publishing Limited, 2011

114

Processed meats

irradiation followed by bacterial spores, vegetative bacterial cells and fungi (yeast and molds) (Ehioba et al., 1988). Gram-negative bacteria and nonspore forming bacteria are generally more sensitive to ionizing radiation than Gram-positive bacteria and sporeforming bacteria (Lambert et al., 1992; Thayer et al., 1993). Low irradiation temperature requires higher radiation doses in order to inactivate foodborne pathogens in meat (Thayer, 1995). Zhu et al. (2008) reported that the D10-values of L. monocytogenes in breast rolls and hams at 4 °C were 0.52 and 0.47 kGy, respectively, and that at least 2.5 kGy irradiation was required to achieve a 5-log reduction of L. monocytogenes in turkey hams and breast rolls at 4 °C. Clardy et al. (2002) reported that the D10-values of L. monocytogenes in ham and cheese sandwiches at −40 °C ranged from 0.71 to 0.81 kGy and a minimum dose of 3.5–4.0 kGy was required to achieve a 5-log reduction of L. monocytogenes. Niemira et al. (2002) also reported that the gamma radiation resistance (D10-value) of L. monocytogenes in frozen vegetables increased significantly when temperature decreased from −5 to −20 °C. The increased D10-values in frozen meat is related to the decreased availability of water molecules for free radical generation by irradiation and the decreased water mobility as more ice crystals are formed at lower temperature conditions. Strains and the substrate in which L. monocytogenes grows influence the sensitivity of L. monocytogenes to irradiation (Augustin, 1996). Sommers et al. (2003a) reported that sodium diacetate (SDA), potassium lactate (PL) and potassium benzoate (PB) combinations in irradiated bologna, turkey hams and breast rolls increased the sensitivity of L. monocytogenes to both gamma- and e-beam radiation. Foong et al. (2004) reported that adding sodium lactate (SL) to RTE meat did not increase radiation sensitivity of L. monocytogenes to e-beam irradiation and Zhu et al. (2009) also reported that adding PB (0.1%) or SL (2%) in turkey rolls failed to prevent L. monocytogenes from growing during refrigerated storage. However, irradiating turkey rolls added with PB + SL or SL + SDA at 1.0 kGy was effective in suppressing the growth of L. monocytogenes for about six weeks when stored at 4 °C (Fig. 5.1). Jin et al. (2009) reported that the combination of pectin–nisin films with ionizing radiation enhanced the microcidal effects of irradiation and prevented listeriosis due to post-processing contamination of RTE meat products. Generalizations about effects of irradiation, however, may be misleading if the irradiation conditions used and commodities to which they are applied are not specified (Diehl, 1992; Sommers and Boyd, 2005).

5.3 Effects of irradiation on meat quality Although irradiation is considered as one of the best methods in controlling pathogens in raw and cooked meat products, the application of irradiation technology in meat industry is extremely limited (80,000 tons/year

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products 8.0

(a)

(a)

Log cfu

Log10cfu/cm2

7.5 7.0 6.5 6.0 5.5 0

7

14

21

28

35

9.00 8.50 8.00 7.50 7.00

Control PB PB+SL PSS SL SL+SDA

6.50 6.00 5.50 5.00 4.50 4.00 0

42

7

8.0

6.5

Log cfu

Log10cfu/cm2

(b)

(b)

7.0 6.0 5.5 5.0 4.5 4.0 3.5

0

7

14

21

28

14

21

28

35

42

35

42

35

42

Storage time (days)

Storage time (days) 7.5

115

35

42

9.00 8.50 8.00 7.50 7.00 6.50 6.00 5.50 5.00 4.50 4.00

Control PB PB+SL PSS SL SL+SDA

0

7

Storage time (days)

14

21

28

Storage time (days)

7.0

(c) (c)

9.00 Control PB+SL SL

8.00

5.0

7.00

4.0

Log cfu

Logcfu/cm2

6.0

3.0 2.0

PB PSS SL+SDA

6.00 5.00 4.00 3.00

1.0 0.0 0

2.00 7

14

21

28

35

42

Storage time (days) Control

PB

PB+SL

PSS

SL

1.00

0

7

14

21

28

Storage time (days) SL+SDA

Irradiated vacuum-packaged Turkey Ham

Uncured breast roll

Fig. 5.1 Survival and growth of L. monocytogenes on irradiated vacuum-packaged ham and uncured breast rolls during 4 °C storage. Control = basic formula, PB = 0.1% potassium benzoate, SL = 2% sodium lactate, PB + SL = 0.1% potassium benzoate and 2% sodium lactate, SL + SDA = 2% sodium lactate and 0.1% sodium diacetate, PSS = 0.1% potassium benzoate, 2% sodium lactate, and 0.1% sodium diacetate. (a) 0 kGy; (b) 1.0 kGy; (c) 2.0 kGy (cfu = colony-forming unit). Adapted from Zhu et al. (2005b), Poultry Sci. 84, 613–620 and Zhu et al. (2008), Poultry Sci, 87, 2140–2145.

© Woodhead Publishing Limited, 2011

116

Processed meats

in the United States) (Kume et al., 2009); and is primarily due to quality and health concerns about irradiated meat products by consumers and because irradiation is only permitted for raw meat and is not permitted for processed meat products. Studies using raw and cooked meat from various animal sources have indicated that irradiation produces a characteristic aroma and color that significantly impacts on consumer acceptance (Kanatt et al., 2007). Consumers associate the off-odor and off-flavor generated by irradiation with undesirable chemical reactions, brown/gray color formation in raw beef as old or low quality meat, and red/pink color in cooked irradiated light meat as undercooked or contaminated (E. J. Lee et al., 2003). Hydroxyl radicals generated from water molecules by ionizing radiation are the most reactive oxygen species, especially in the presence of oxygen (Thakur and Singh, 1994; Diehl, 1995). Generally meat contains about 75% water, and thus ionizing irradiation can more effectively generate hydroxyl radicals from meat. Because hydroxyl radicals can initiate lipid oxidation, irradiation is expected to accelerate lipid oxidation in meat and meat products. However, Ahn et al. (2000b) and Du et al. (2001) reported that irradiation increased values of 2-thiobarbituric acid reactive substances (TBARS) in raw and cooked meat only under aerobic packaging conditions. Lipid oxidation in irradiated meat did not progress without oxygen (Ahn et al., 1998a,b). Under aerobic conditions, TBARS had very strong correlations with the amounts of aldehydes, total volatiles and ketones in irradiated meat, but TBARS values in vacuum-packaged irradiated raw and cooked meat did not correlate well with the amount of volatiles present. Halliwell and Gutteridge (1990) reported that hydroxyl radicals can be formed from oxygen through the Fenton reaction in the presence of iron. Therefore, the presence of oxygen has a significant effect on the development of lipid oxidation and odor production in meat (Merritt et al., 1975). Cooked meat was more susceptible to oxidative changes than raw meat because the phospholipid structure in muscle cell membranes are damaged during cooking (Ahn et al., 1992). Irradiation (4.5 kGy) of cured meat products increased TBARS values of cooked pork sausages, but the difference disappeared during 7 days of storage at 4 °C as TBARS increased in all samples. Cured RTE meat products were more resistant to oxidative changes than uncured meat products even after irradiation at low doses (Zhu et al., 2004c; 2005b; Houser et al., 2005) because of the strong antioxidant effects associated with nitrite in cured meat products. However, Houser et al. (2003) reported that irradiation at 4.5 kGy increased lipid oxidation in cured ham. Ahn et al. (1992) suggested that excluding oxygen from meat after cooking, whether irradiated or not, was very important in preventing oxidative chain reactions in meat products. In addition, preventing oxygen exposure of cooked meat was more important for cooked meat quality than packaging and storage conditions of raw meat either before or after irradiation (Ahn et al., 1999, 2000b).

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

117

It is widely understood that the fatty acid composition of meat plays an important role in its susceptibility to lipid oxidation; this is of even greater importance for irradiated meat. Generally polyunsaturated fatty acids are more susceptible to oxidative changes than monounsaturated or saturated fatty acids in both irradiated and non-irradiated meat. Lee and Ahn (2003) reported that TBARS values of irradiated oil emulsion, especially prepared with arachidonic acid, linolenic acid and fish oil, developed higher TBARS values than non-irradiated equivalents after 10 days of storage. The use of irradiation with meat products has been shown to greatly increase the quantities of volatile compounds associated with such products as well as producing novel forms of volatile compounds, such as aldehydes (2-methyl butanal and 3-methyl butanal), hydrocarbons (1-hexene, 1-heptene, 1-octene and 1-nonene) and sulfur compounds (hydrogen sulfide, sulfur dioxide, mercaptomethane, dimethyl sulfide, methyl thioacetate, dimethyl disulfide and trimethyl sulfide) (Ahn et al., 2000a; Fan et al., 2002). However, among these volatiles it is the sulfur compounds that have played the most important roles in effecting the associated sensory characteristics of irradiated meat (Hashim et al., 1995; Ahn and Lee, 2002). The odor intensity of sulfur compounds has been reported to be much stronger and stringent than that of other compounds (Lee and Ahn, 2003) and sulfur compounds have very low odor thresholds (Shankaranarayana et al., 1974; Gemert, 2003). Houser et al. (2003) reported that irradiated cured cooked ham had higher off-odor scores than non-irradiated equivalents. Zhu et al. (2004c) also reported that the contents of sulfur compounds and sulfury odor intensity in RTE turkey ham were irradiation dose-dependent. Irradiation produced a metal-like flavor in RTE turkey hams due to increased production of acetaldehyde, but irradiation up to 2 kGy had only minor impact on the overall quality of the product. Although cooking also produced sulfur compounds from meat, the amounts of sulfur compounds produced by irradiation were much higher than those generated through cooking (Ahn et al., 2000a). Several researchers have tested the sulfur theory for off-odor production in irradiated meat using aqueous model systems. Ahn (2002) and Ahn and Lee (2002) showed that the odor characteristic of irradiated sulfur-containing amino acid homopolymers have similar odor characteristics to irradiated meat (Table 5.4). Methionine and cysteine were the major sulfur-containing amino acids among meat components, but the amount of sulfur compounds produced from methionine was more than 99% of the total sulfur compounds produced by irradiation. This indicated that the side chain of methionine was highly susceptible to radiolytic degradation. The primary sulfur compounds produced by irradiation interacted with sulfur compounds as well as other volatile compounds to produce secondary sulfur compounds. Other studies pertaining to the volatile profiles and sensory characteristics of amino acids also indicated that the major volatile components

© Woodhead Publishing Limited, 2011

118

Processed meats

Table 5.4 Major volatile compounds from irradiated amino acid homopolymers and oligomers and their odor characteristics Amino acid polymer

Major volatiles

Poly-aspartic acid

2-Propanone, methyl cyclopentane, toluenea Acetaldehyde, 2-propanone Acetonitrile, methyl propionate, acetaldehyde, 2-propanone Acetaldehyde, 2-methyl propanal, 2-methyl butanal, 3-methyl propanal 2-Propanone, hexane Acetaldehyde, 1,1-oxybis ethane, 2-propanone Acetaldehyde, 2-propanone, acetic acid ethyl ester, 2-ethoxy butane, 2,3-dihydro-1,4-dioxin, 1,4-dioxin, methyl butyrate, 1,1-oxybis ethane Methyl cyclopentane, benzene, toluene Acetaldehyde, 1,1-oxybis ethane, 2-propanone Acetaldehyde, tetrahydrofuran, 2-methyl-1,3-dioxalane, benzene, toluene, cyclohexane, 2,3-dihydro-1,4-dioxin 2-Methoxy-2-methyl propane, toluene Acetaldehyde, propanal, butanal, 2-methyl dioxalone, benzene, 2-propanone Carbon disulfide, dimethyl disulfide, methyl cyclopentane Acetaldehyde, mercaptomethane, dimethyl sulfide, methyl thiirane, 3-(methylthio)-1-propene, ethanoic acid-S-methyl ester, dimethyl disulfide, methyl ethyl disulfide, 2,4-dithiapentane, 2-methyl propanal Mercaptomethane, pentanal, dimethyl sulfide, (methylthio)-ethane, benzene, 1-heptanethiol, 3-(methylthio)-1propene, ethanoic acid-S-methyl ester, dimethyl disulfide, methyl ethyl disulfide, 2-butanamine, 1,3-dimethyl benzene, 1,4-dimethyl benzene, isopropyl benzene, ethyl benzene

Poly-glutamic acid Poly-alanine Poly-glycine Poly-proline Poly-serine Poly-threonine

Poly-asparagine Poly-glutamine Poly-tyrosine

Poly-histidine Poly-lysine Glutathione Met-Ala

Met-Gly-Met-Met

Odor characteristics No odor Sweet, honey Seaweed Seashore odor Organic solvent Cattle barn odor Chinese herbal medicine No odor Hospital odor Seaweed or seashore Sweet Coleslaw, sour Hard-boiled eggs, sulfury Boiled eggs, sulfury Rotten vegetable Boiled cabbage, sulfury, Rotten vegetable

a Volatiles written in italic did not produce detectable odor at the levels found in the samples. Adopted from Ahn (2002), J Food Sci, 67(7), 2565–2570.

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

119

responsible for the characteristic off-odor in irradiated meat were sulfur compounds and volatiles from lipids accounted for only a small part of the off-odor in irradiated meat (Ahn et al., 1998b, 1999, 2000a). Dogbevi et al. (1999) assumed that deamination during irradiation is one of the main steps involved in the mechanisms of radiolytic degradation of amino acids. Mottram et al. (2002) reported that the branched chain of aldehydes was produced by the degradation of amino acids via Strecker degradation during irradiation. Jo and Ahn (2000) also reported that 3-methyl butanal and 2-methyl butanal were produced from leucine and isoleucine, respectively, by radiolytic degradation of their side chains. Irradiation of N-acetyl amino acids and peptides in the presence of oxygen can produce hydroperoxides from both side chains and the amino acid backbone (at alpha-carbon positions) (Davies, 1996). The release of volatile compounds from meat, however, can be affected by the physicochemical conditions of meat and the interactions of volatiles with meat components (Godshall, 1997; Lubbers et al., 1998). Therefore, volatile compounds released from real meat systems could be significantly different from those generated through the use of the aqueous model systems (Jo and Ahn, 2000). Various factors, such as irradiation dose, animal species, muscle type, additives and packaging type affect color changes in irradiated meat (Patterson and Stevenson, 1995; Luchsinger et al., 1996; Nanke et al., 1999). The a*-value (redness) of light meats such as poultry breast and pork loin was increased by irradiation in both aerobically and vacuum-packaging systems (Luchsinger et al., 1997a). However, during storage vacuum-packaged meat was significantly redder than aerobically packaged equivalents (Nanke et al., 1998, 1999). Du et al. (2001) reported that consumers did not like the off-flavor produced but preferred the color induced by irradiation to nonirradiated RTE turkey breast rolls. Lefebvre et al. (1994) also reported that sensory panelists preferred the red color of irradiated light meats to nonirradiated equivalents because the red color of irradiated meat looked fresher in appearance. If the red color is retained in meats after cooking, this can cause a problem because the meat may be considered undercooked or contaminated (Ahn and Lee, 2006). In irradiated red meats such as beef, the formation of a greenish-brown color under aerobic conditions is an important quality issue (Nam and Ahn, 2003b). Uncured cooked meat also produced pink coloration following irradiation (Du et al., 2001). However, the degree of color change in irradiated cured meat products is minor compared with that of uncured processed products (Shahidi et al., 1991). The major color change in cured cooked products is fading (decrease in redness values) by irradiation (Jo et al., 1999; Sommers et al., 2001; Houser et al., 2005). To explain the mechanism of color change in irradiated meat, early researchers (Tappel, 1956) assumed that the oxymyoglobin formed from metmyoglobin and hydroxyl radicals caused the bright red color in irradiated light meats. Nanke et al. (1998) also proposed that the color

© Woodhead Publishing Limited, 2011

120

Processed meats

compound in irradiated meat was an oxymyoglobin (oxyMb)-like pigment. However, the red pigment cannot be an oxyMb because the red color formed by irradiation can be produced under anoxic conditions. Millar et al. (1995) insisted that a ferrous myoglobin derivative such as carboxyl– myoglobin or nitric oxide–myoglobin was a more important factor than oxymyoglobin in terms of producing the red/pink color in irradiated light meats (pork, poultry, etc.). Another theory for the red color change in irradiated meat was related to carbon monoxide production. Irradiation produced considerable amounts of carbon monoxide from organic components such as alcohols, aldehydes, ketones, carboxylic acids, amides and esters (Furuta et al., 1992). Nam and Ahn (2002a,b) reported that carbon monoxide-myoglobin (CO-Mb) produced the pink color in irradiated light meats. To support this theory, Lee and Ahn (2004) measured the amount of CO gas using a model system and showed that irradiation produced CO from meat components such as glycine, asparagine, glutamine, pyruvate, glyceraldehydes, α-ketoglutarate and phospholipids. − Irradiation generally produces aqueous electrons (eaq ) and hydrogen radicals that have reducing power attained from water molecules. Therefore, irradiation decreases oxidation-reduction potential (ORP) in meat (Thakur and Singh, 1994). The lower ORP in irradiated meat, however, was maintained only under vacuum-packaging conditions (Nam and Ahn, 2002b). Maintaining reducing conditions (low ORP conditions) in meat is very important for CO–Mb formation because the CO–Mb complex can only be formed when the heme pigment is in reduced form (Cornforth et al., 1986). Therefore, the decrease of ORP and CO production by irradiation is an important factor for CO–Mb ligand formation of irradiated light meat (Nam and Ahn, 2002a,b; Brewer, 2004). However, in irradiated red meat, ORP or the status of heme pigments is more important factor than CO production or CO–Mb ligand formation because the content of heme pigments in beef is about 10 times greater than that of light meats and the proportion of carbon monoxide myoglobin (CO–Mb) to total heme pigments in irradiated beef is small (Ahn and Lee, 2006). Irradiation has been shown to significantly decrease water holding capacity in meat because of the damage to muscle fibers (Lakritz et al., 1987) and the denaturation of muscle proteins (Lynch et al., 1991). Zhu et al. (2004a) reported that irradiation increased centrifugation loss of water in pork loins. Significant differences in the size of myofibril units (sarcomeres) between irradiated and non-irradiated chicken breasts were also found (Yoon, 2003). Lee and Ahn (2005) found that addition of 3% or higher of plum extract improved the mouthfeel and antioxidant effect of irradiated turkey breast rolls. Conversely, other researchers have postulated that irradiation has had minimal effects on texture of frozen, raw and precooked ground beef patties (Fu et al., 1995b), frozen and chilled boneless beef steaks (Luchsinger et al., 1997b), ham structure (Sommers et al., 2002b) or RTE turkey breast rolls (Zhu et al., 2004d).

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

121

Cabeza et al. (2009) reported that irradiation of vacuum-packed dry fermented sausages at ≤2 kGy had negligible effects on their sensory characteristics (appearance, odor and taste). The aroma and flavor quality of irradiated (0, 1.8 or 2.6 kGy) frankfurters formulated with 3% potassium lactate/sodium diacetate solution were retained for 4 weeks under aerobic conditions or for 8 weeks under vacuum packaged conditions at 4 °C (Knight et al., 2007). Hoz et al. (2008) suggested that irradiation at 1 and 2 kGy had negligible sensory modifications (appearance, odor and flavor) in irradiated vacuum-packaged dry-cured ham. However, irradiation of dry-cured ham at 3 and 4 kGy increased the intensity of off-odors and off-flavors. The primary reason for the limited application of irradiation technology by the meat industry today is due to consumer acceptance of irradiated meat (AMIF, 1993). Many consumers still misunderstand the effectiveness, safety and functional benefits of irradiation, even though governments and industries have openly supported the introduction of irradiated foods to the marketplace for several years (Fox et al., 2002). Consumers’ willingness to buy irradiated foods varies and depends on gender, education level, income, geographic location and exposure to irradiated food products (Frenzen et al., 2001). However, the most important factor for the acceptance of irradiated foods is consumers’ knowledge and understanding about irradiated foods (Lusk et al., 1999).

5.4 Prevention of quality changes in irradiated processed meat In order to harness and implement irradiation technology within the meat industry, it is very important that prevention methods are developed to limit the quality changes in irradiated meat. Various additives and packaging types have been tested to prevent or minimize the quality changes in irradiated meat. Synthetic antioxidants, such as BHT, BHA and propyl gallate, are usually added in meat products during processing to prevent oxidative rancidity and color changes, and retard development of off-flavors (Morrissey et al., 1997; Xiong et al., 1993). In recent years, however, owing to consumer demands for natural antioxidants, natural antioxidants have also been widely tested for use in irradiated and non-irradiated meat products (E. J. Lee et al., 2003; S. C. Lee et al., 2003; Nam et al., 2006). Addition of quercetin, ascorbyl palmitate, α-tocopherol and β-carotene was found to be effective in inhibiting lipid oxidation of irradiated raw and cooked pork and beef (Chen et al., 1999; Lee et al., 1999). Galán et al. (2009) reported that folic acid (0.6, 1.2 and 2.4 mg/100 g) was effective in enhancing color, texture and sensory qualities of hamburgers irradiated up to 3 kGy. Du and Ahn (2002) found that sesamol had a very strong antioxidant effect in turkey sausage, but rosemary extract had a weak antioxidant effect. Plant extracts such as green tea and grape seed extracts also inhibited irradiation-induced

© Woodhead Publishing Limited, 2011

122

Processed meats

TBARS numbers and non-volatile carbonyl compounds in the cooked chicken breast (Rababah et al., 2004). Nitrite or nitrate used in cured RTE meat products are known to have strong antioxidant effects. Fan et al. (2004) reported that addition of sodium nitrite to irradiated cooked bologna significantly lowered lipid oxidation, but was not effective in reducing volatile sulfur compounds in the products. Antioxidants such as vitamin E can be incorporated in meat by dietary regime: Dietary supplementation of vitamin E has been shown to reduce the extent of lipid oxidation in irradiated meat during storage (Wen et al., 1996; Winne and Dirinck, 1996; Morrissey et al., 1997; Formanek et al., 2001). Zhu et al. (2004b, 2005b) suggested that combined use of irradiation and antimicrobial agents such as lactate, acetate and sorbate can improve the safety of meat products without significant impact on meat quality. Nam et al. (2001) and Nam and Ahn (2002c) used inorganic acids to reduce color problems in irradiated light meats because color intensity can be lower at a lower pH than at a higher pH, but lowering pH did not significantly impact on the redness values of irradiated light meats. In red meat, reducing agents such as ascorbic acid were very effective in maintaining redness and preventing greenish brown discoloration by irradiation (Nam et al., 2003a) because the color mechanisms of irradiated light meat and red meat were different, as discussed previously. In irradiated ground beef, ascorbic acid lowered ORP values and maintained heme pigments in ferrous status and stabilized color (Nam and Ahn, 2003b). Overall, antioxidants were effective in inhibiting lipid oxidation and related volatiles, but had minimal effects on the production of irradiation-induced sulfur compounds and off-odor (Nam et al., 2001; Fan, 2005). Packaging can play important roles in relation to the color, lipid oxidation and volatiles produced in irradiated meat. Vacuum-packaging prevents lipid oxidation but retains off-odor volatiles produced by irradiation in the package. Aerobic-packaging accelerates oxidative changes but eliminates the build-up of off-odor volatiles in packs of irradiated meat by diffusion and permeation of volatiles through the packaging materials (Ahn et al., 2001b; Nam et al., 2003a,b). To minimize quality issues in irradiated meat (off-odor, color change and lipid oxidation), Ahn and his colleagues combined the merits of packaging and antioxidants on meat quality: they have implemented a new packaging concept called ‘double packaging’, in which both aerobic and vacuum packaging are combined. The term ‘double-packaging’ is used to describe a packaging method in which meat pieces are individually packaged in oxygen permeable bags first and then a few of aerobic packages were vacuum-packaged in a larger vacuum bag before irradiation. The outer bag of the irradiated meat is removed at retail level a few days before display or use, thereby presenting the meat packs to the consumer in aerobically packaged formats. Double-packaging was effective in eliminating all the volatile sulfur compounds and off-odor problems (Nam and Ahn, 2002c), but was not

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

123

completely effective in solving color and lipid oxidation issues in irradiated meat. When an antioxidant such as gallate, α-tocopherol or sesamol was combined with the double-packaging systems, however, all three major quality issues of light meat (color changes, off-odor and lipid oxidation) could be solved (Nam and Ahn, 2003c). However, no commercial company is using the double-packaging and antioxidant combination method at this point because use of additives for irradiated meat is not permitted. In irradiated ground beef, the combined use of double-packaging and ascorbic acid was an excellent method to maintain the bright red color of beef, because irradiating under vacuum conditions and adding reducing agent helped maintaining myoglobin in a reduced form (Ahn and Nam, 2004; Nam et al., 2008).

5.5 Future trends Most of the irradiation studies relating to quality issues have been carried out to date with raw meat, because irradiation is not permitted for use with meats containing additives, further processed or precooked RTE meat products. Therefore, future irradiation studies should be focused on further processed and precooked ready-to-eat meat products, especially in relation to investigating methods to prevent negative flavor, odor and taste modifications, as well as investigating approaches to improving microbial safety in these products. Additionally, limited research has been conducted to date on dried and semi-dried meat products. Dried and semi-dried meat products contain much lower levels of water than normal meat products, and thus the irradiation efficiency and the response of meat to irradiation could be different from those of normal products. Therefore, microbial and quality research on dried and semi-dried processed meat products is required. Currently, no information on the mechanisms and causes of odor/taste/ flavor changes in irradiated processed meat products is available. Herbs and spices are used in most of the processed meat products and they play important roles in producing flavor and improving the stability of meat products. Some of the volatiles from spices and herbs can interact with sulfur compounds produced by irradiation, and modify the overall flavor and taste of the products (Yang et al., 2011). Certain herbs and spices produce large amounts of sulfur compounds and some of them are reported to increase radiation sensitivity of pathogens. Therefore, proper use of these herbs and spices can be an excellent tool to mask or minimize irradiation flavor/taste as well as improve microbial safety of irradiated processed meat. Little research on the effect of spices and herbs on microcidal efficiency of irradiation as well as masking flavor/taste of processed meat products, however, has been done and future research should be focused in this area.

© Woodhead Publishing Limited, 2011

124

Processed meats

5.6 Acknowledgement This work was supported jointly by Iowa State University, and WCU (World Class University) program (R31-10056) through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology.

5.7 References and further reading achinewhu s c, ogbonna c c and hart a d (1995), ‘Chemical composition of indigenous wild herbs, spices, fruits, nuts and leafy vegetables used as food’, Plant Foods Human Nutr, 48, 341–348. ahn d u (2002), ‘Production of volatiles from amino acid homopolymers by irradiation’, J Food Sci, 67, 2565–2570. ahn d u and lee e j (2002), ‘Production of off-odor volatiles from liposome-containing amino acid homopolymers by irradiation’, J. Food Sci, 67(7), 2659–2665. ahn d u and lee e j (2004), ‘Mechanisms and prevention of off-odor production and color changes in irradiated meat’, ACS Symp Ser, 875, 43–76. ahn d u and lee e j (2006), ‘Mechanisms and prevention of quality changes in meat by irradiation’. In C Sommers and X Fan Eds., Food Irradiation Research and Technology, IFT Symp Book Ser, Ames, IA, Blackwell, 127–142. ahn d u and nam k c (2004), ‘Effects of ascorbic acid and antioxidants on color, lipid oxidation and volatiles of irradiated ground beef’, Rad Phys Chem, 71(1/2):151–156. ahn d u, wolfe f h, sim j s and kim d h (1992), ‘Packaging cooked turkey meat patties while hot reduces lipid oxidation’, J Food Sci, 57, 1075–1077, 1115. ahn d u, olson d g, jo c, chen x, wu c and lee j l (1998a), ‘Effect of muscle type, packaging, and irradiation on lipid oxidation, volatile production, and color in raw pork patties’, Meat Sci, 49, 27–39. ahn d u, olson d g, lee j i, jo c, wu c and chen x (1998b), ‘Packaging and irradiation effects on lipid oxidation and volatiles in pork patties’, J Food Sci, 63(1), 15–19. ahn d u, olson d g, jo c, love j and jin s k (1999), ‘Volatiles production and lipid oxidation of irradiated cooked sausage with different packaging during storage’, J Food Sci, 64(2), 226–229. ahn d u, jo c and olson d g (2000a), ‘Analysis of volatile components and the sensory characteristics of irradiated raw pork’, Meat Sci, 54, 209–215. ahn d u, jo c, olson d g and nam k c (2000b), ‘Quality characteristics of pork patties irradiated and stored in different packaging and storage conditions’, Meat Sci, 56, 203–209. ahn d u, nam k c, du m and jo j (2001a), ‘Volatile production of irradiated normal, pale, soft exudative (PSE) and dark firm dry (DFD) pork with different packaging and storage’, Meat Sci, 57, 419–426. ahn d u, nam k c, du m and jo c (2001b), ‘Effect of irradiation and packaging conditions after cooking on the formation of cholesterol and lipid oxidation products in meats during storage’, Meat Sci, 57, 413–418. ahn d u, lee e j and mendonca a (2006), ‘Meat decontamination by irradiation’. In Nollet L M L and Toldra F, Advanced Technologies for Meat Processing, Boca Raton, FL, CRC Press, 155–191. al-jalay b, blank g, mcconnel b, and al-khayat, m (1987), ‘Antioxidant activity of selected spices used in fermented meat sausage’, J Food Protec, 50, 25–27.

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

125

ama (1993), Irradiation of Food, Chicago, IL, Council on Scientific Affairs Report 4 of American Medical Association. amif (1993), Consumer Awareness, Knowledge, and Acceptance of Food Irradiation, Washington, DC, American Meat Institute Foundation. andrews l s, ahmedna m, grodner r m, liuzzo j a, murano p s, murano e a, rao r m, shane s and wilson p w (1998), ‘Food preservation using ionizing radiation’, Rev Environ Contam Toxicol, 154, 1–53. augustin j c (1996), ‘Resistance of Listeria monocytogenes to physical exposure’, Pathol Biol (Paris), 44, 790–807. autio t, sateri t, fredriksson-ahomaa m, rahkio m, lunden j and korkeala h (2000), ‘Listeria monocytogenes contamination pattern in pig slaughterhouses’, J Food Protec, 63, 1438–1442. bajpai v k, rahman a, dung n t, huh m k and kang s c (2008), ‘In vitro inhibition of food spoilage and food borne pathogenic bacteria by essential oil and leaf extracts of Magnolia liliflora desr’, J Food Sci, 73, 314–320. bedie g k, samelis j, sofos j n, belk k e, scanga j a and smith g c (2001), ‘Antimicrobials in the formulation to control Listeria monocytogenes postprocessing contamination on frankfurters stored at 4 degrees C in vacuum packages’, J Food Protec, 64, 1949–1955. beresford m r, andrew p w and shama g (2001), ‘Listeria monocytogenes adheres to many materials found in food-processing environments’, J Appl Microbiol, 90, 1000–1005. brewer s (2004), ‘Irradiation effects on meat color – a review’, Meat Sci, 68, 1–17. cabeza m c, cambero i, hoz l and ordóñez j a (2007), ‘Optimization of E-beam irradiation treatment to eliminate Listeria monocytogenes from ready-to-eat (RTE) cooked ham’, Innov Food Sci Emerg Technol, 8(2), 299–305. cabeza m c, cambero i, hoz l, velasco r, camberoand m i and ordóñez j a (2009), ‘Safety and quality of ready-to-eat dry fermented sausages subjected to E-beam radiation’, Meat Sci, 83, 320–327. caillet s, millette m, turgis m, salmieri s, lacroix m (2006), ‘Influence of antimicrobial compounds and modified atmosphere packaging on radiation sensitivity of Listeria monocytogenes present in ready-to-use carrots (Daucus carota)’, J Food Protec, 69(1), 221–227. cast (1989), Ionizing Energy in Food Processing and Pest Control: II. Applications, Ames, Iowa, Task Force Report No. 115 of Council for Agriculture Science and Technology, pp. 72–76. cdc (1999), ‘Update: multistate outbreak of listeriosis – United States’, Morb Mortal Wkly Rep, 47, 1117–1118. cdc (2000), ‘Multistate outbreak of listeriosis – United States’, Morb Mortal Wkly Rep, 49, 1129–1130. cdc (2002), ‘Multistate outbreak of listeriosis – United States. Morb Mortal Wkly Rep, 51, 950–951. chen x, jo c, lee j i and ahn d u (1999), ‘Lipid oxidation, volatiles and color changes of irradiated pork patties as affected by antioxidants’, J Food Sci, 64(1), 16–19. clardy s, foley d m, caporaso f, calicchia m l and prakash a (2002), ‘Effect of gamma irradiation on Listeria monocytogenes in frozen, artificially contaminated sandwiches’, J Food Protec, 65, 1740–1744. clavero m r, monk j d, beuchat l r, doyle m p and brackett r e (1994), ‘Inactivation of Escherichia coli O157 : H7, Salmonellae, and Campylobacter jejuni in raw ground beef by gamma irradiation’, Appl Environ Microbiol, 60, 2069–2075. cornforth d p, vahabzadeh f, carpenter c e and bartholomew d t r (1986), ‘Role of reduced hemochromes in pink color defect of cooked turkey rolls’, J Food Sci, 51, 1132–1135.

© Woodhead Publishing Limited, 2011

126

Processed meats

davies m j (1996), ‘Protein and peptide alkoxyl radicals can give rise to C-terminal decarboxylation and backbone cleavage’, Arch Biochem Biophys, 336, 163–172. dawidowicz a l, wianowska d and baraniak b (2006), ‘The antioxidant properties of alcoholic extracts from Sambucus nigra L. (antioxidant properties of extracts)’ LWT Food Sci Technol, 39(3), 308–315. diehl j f (1992), ‘Food irradiation: is it an alternative to chemical preservatives’, Food Addit Contam, 9, 409–416. diehl j f (1995), Safety of Irradiated Foods, 2nd Ed. Marcel Dekker, Inc., New York. dogbevi m k, vachon c and lacroix m (1999), ‘Physicochemical and microbiological changes in irradiated fresh pork loins’, Meat Sci, 51, 349–354. dorman h j d and deans s g (2000), ‘Antimicrobial agents from plants: antibacterial activity of plant volatile oils’, J Appl Microbiol, 88, 308–316. du m and ahn d u (2002), ‘Effect of antioxidants on the quality of irradiated sausages prepared with turkey thigh meat’, Poultry Sci, 81, 1251–1256. du m, ahn d u, mendonca a f and wesley i v (2001), ‘Quality characteristics of irradiated ready-to-eat breast rolls from turkeys fed conjugated linoleic acid’, Poultry Sci, 81(9), 1378–1384. ehioba r m, kraft a a, molins r a, walker h w, olson d g, subbaraman g and skowronski r p (1988), ‘Identification of microbial isolates from vacuum-packaged ground pork irradiated at 1 kGy’, J Food Sci, 53, 278–279, 281. fan x (2005), Nature, cause, and control of irradiation-induced off-odor in readyto-eat meat products. In Sucan M K, Ed., Process and Reaction Flavors, ACS Symposium Series, Vol. 905, Cary, NC, Oxford University Press, 208–221. fan x, sommers c h, thayer d w and lehotay s j (2002), Volatile sulfur compounds in irradiated precooked turkey breast analyzed with pulsed flame photometric detection, J Agric Food Chem, 50(15), 4257–4261. fan x, sommers ch and sokorai k j b (2004), ‘Ionizing radiation and antioxidants affect volatile sulfur compounds, lipid oxidation and color of ready-to-eat turkey bologna’, J Agric Food Chem, 52, 3509–3515. farber j m and peterkin p i (1991), ‘Listeria monocytogenes, a food-borne pathogen’, Microbiol Rev, 55, 476–511. fda (2000), Irradiation in the production, processing, and handling of food – Final Rule, 21 CFR Part 179, 65(141), 45280–45282. http://www.gpo.gov/fdsys/pkg/ FR-2000-07-21/pdf/00-18496.pdf. Accessed Aug 3, 2010. fda (2005), Irradiation in the production, processing, and handling of food – Final Rule, 21 CFR Part 179, 70(157), 48057–48073. http://www.fda.gov/OHRMS/ DOCKETS/98fr/05-16279.pdf. Accessed Aug 3, 2010. fda (2008), Irradiation in the production, processing, and handling of food – Final Rule, 21 CFR Part 179, 73(164), 49593–49603. http://www.gpo.gov/fdsys/pkg/ FR-2008-08-22/pdf/E8-19573.pdf. Accessed Aug 3, 2010. foong s c, gonzalez g l and dickson j s (2004), ‘Reduction and survival of Listeria monocytogenes in ready-to-eat meats after irradiation’, J Food Protec, 67, 77–82. formanek z, kerry j p, higgins f m, buckley d j, morrissey p a and farkas j (2001), ‘Addition of synthetic and natural antioxidants to α-tocopheryl acetate supplemented beef patties: effects of antioxidants and packaging on lipid oxidation’, Meat Sci, 58(4), 337–341. fox j a, hayes d j and shogren j f (2002), ‘Consumer preferences for food irradiation: how favorable and unfavorable descriptions affect preferences for irradiated pork in experimental auctions’, J Risk Uncertainty, 24(1), 75–95. frenzen p d, debess e e, hechemy k e, kassenborg h, kennedy m, mccombs k and mcnees a (2001), ‘Consumer acceptance of irradiated meat and poultry in the United States’, J Food Protec, 64, 2020–2026.

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

127

fsis (2003), ‘FSIS rule designed to reduce Listeria monocytogenes in ready-to-eat meat & poultry’, available from: http://www.fsis.usda.gov/factsheets/fsis_rule_ designed_to_reduce_listeria/index.asp. [accessed August 3, 2010]. fu a h, sebranek j g and murano e a (1995a), ‘Survival of Listeria monocytogenes and Salmonella typhimurium and quality attributes of cooked pork chops and cured ham after irradiation’, J Food Sci, 60, 1001–1005. fu a h, sebranek j g and murano e a (1995b), ‘Survival of Listeria monocytogenes, Yersinia enterocolitica, and Escherichia coli O157 : H7 and quality changes after irradiation of beef steak and ground beef’, J Food Sci, 60, 972–977. furuta m, dohmaru t, katayama t, toratoni h and takeda a (1992), ‘Detection of irradiated frozen meat and poultry using carbon monoxide gas as a probe’, J Agri Food Chem, 40(7), 1099–1100. galán i, garcía m l and selgas m d (2009), ‘Effects of irradiation on hamburgers enriched with folic acid’, Meat Sci, 84, 437–443. gemert l j (2003), Odor Thresholds – Compilations of Odor Threshold Values in Air, Water and Other Media, Zeist, The Netherlands. gillespie i, little c and mitchell r (2000), ‘Microbiological examination of cold ready-to-eat sliced meats from catering establishments in the United Kingdom’, J Appl Microbiol, 88, 467–474. godshall m a (1997), ‘How carbohydrate influence flavor’, Food Technol, 51, 63–67. gursel b and gurakan g c (1997), ‘Effects of gamma irradiation on the survival of Listeria monocytogenes and on its growth at refrigeration temperature in poultry and red meat’, Poultry Sci, 76, 1661–1664. halliwell b and gutteridge j m c (1990), ‘Role of free radicals and catalytic metal ions in human disease: an overview’, Methods Enzymol, 186, 1–85. hashim i b, resurreccion a v a and mcwatters k h (1995), ‘Consumer acceptance of irradiated poultry’, Poultry Sci, 74, 1287–1294. heath j l, owens s l, tesch s and hannah k w (1990), ‘Effect of high-energy electron irradiation of chicken on thiobarbituric acid values, shear values, odor, and cook yield’, Poultry Sci, 69, 313–319. houser t a, sebranek j g and lonergan s m (2003), ‘Effects of irradiation on properties of cured ham’, J Food Sci, 68(7), 2362–2365. houser t a, sebranek j g, masionet w n, cordray j c, wiegand b r, ahn d u and lee e j (2005), ‘The effects of irradiation at 1.6 kGy on quality characteristics of commercially produced ham and pork frankfurters over extended storage, J Food Sci, 70(4), S262–S266. hoz l, cambero m i, cabeza m c, herrero a m and ordóñez j a (2008), ‘Elimination of Listeria monocytogenes from vacuum-packed dry-cured ham by E-beam radiation’, J Food Protec, 71(10), 2001–2006. iaea (1999), ‘Facts about food irradiation’, Vienna, Austria, International Atomic Energy Agency, Available from: http://www.iaea.org/nafa/d5/public/foodirradiation.pdf [accessed 8 July 2010]. jin t, liu l, sommers c h, boyd g and zhang h (2009), ‘Radiation sensitization and postirradiation proliferation of Listeria monocytogenes on ready-to-eat deli meat in the presence of pectin-nisin films’, J Food Protec, 72(3), 644–649. jo c and ahn d u (2000), ‘Production of volatile compounds from irradiated oil emulsion containing amino acids or proteins’, J Food Sci, 65, 612–616. jo c, lee j l and ahn d u (1999), ‘Lipid oxidation, color changes and volatiles production in irradiated pork sausage with different fat content and packaging during storage’, Meat Sci, 51, 355–361. kanatt s r, chander r and sharma a (2007), ‘Antioxidant potential of mint (Mentha spicata L.) in radiation-processed lamb meat‘, Food Chem, 100(2), 451–458.

© Woodhead Publishing Limited, 2011

128

Processed meats

knight t d, miller r, maxim j and keeton j t (2007), ‘Sensory and physiochemical characteristics of frankfurters formulated with potassium lactate and sodium diacetate before and after irradiation’, J Food Sci, 72(2), S112–S118. kumar m and berwal j s (1998), ‘Sensitivity of food pathogens to garlic (Allium sativum)’, J Appl Microbiol, 84, 213–215. kume t, furuta m and todoriki s (2009), Quantity and economic scale of food irradiation in the world, Radioisotopes, 58, 25–35. lakritz l, carroll r j, jenkins r k and maerker g (1987), ‘Immediate effects of ionizing-radiation on the structure of unfrozen bovine muscle-tissue’, Meat Sci, 20, 107–117. lambert a d, smith j p and dodds k l (1992), ‘Physical, chemical, and sensory changes in irradiated fresh pork packaged in modified atmosphere’, J Food Sci, 57, 1294–1299. lee e j and ahn d u (2003), ‘Effect of antioxidants on the production of off-odor volatiles and lipid oxidation in irradiated turkey breast meat and meat homogenates’, J Food Sci, 68, 1631–1638. lee e j and ahn d u (2004), ‘Sources and mechanisms of carbon monoxide production by irradiation’, J Food Sci, 69(6), c485–c490. lee e j and ahn d u (2005), ‘Quality characteristics of irradiated turkey breast rolls formulated with plum extract’, Meat Sci, 71, 300–305. lee e j, love j and ahn d u (2003), ‘Effect of antioxidants on the consumer acceptance of irradiated turkey meat’, J Food Sci, 68(5), 1659–1663. lee j w, yook h s, kim s a, lee k h and byun m w (1999), ‘Effects of antioxidants and gamma irradiation on the shelf life of beef patties’, J Food Protec, 62(6), 619–624. lee s c, kim j h, nam k c and ahn d u (2003), ‘Antioxidant properties of far infraredtreated rice hull extract in irradiated raw and cooked turkey breast’, J Food Sci, 68, 1904–1909. lefebvre n, thibault c, charbonneau r and piette j p g (1994), ‘Improvement of shelf-life and wholesomeness of ground beef by irradiation 2: chemical analysis and sensory evaluation’, Meat Sci, 36, 371–380. lemaire v, cerf o and audurier a (1989), ‘Thermal resistance of Listeria monocytogenes’, Ann Rech Vet, 20, 493–500. lewis s j, velasquez a, cuppett s l and mckee s r (2002), ‘Effect of electron beam irradiation on poultry meat safety and quality’, Poultry Sci, 81, 896–903. lopez-gonzalez v, murano p s, brennan r e and murano e a (1999), ‘Influence of various commercial packaging conditions on survival of Escherichia coli O157 : H7 to irradiation by electron beam versus gamma rays’, J Food Protec, 62, 10–15. lubbers s, landy p and voilley a (1998), ‘Retention and release of aroma compounds in foods containing proteins’, Food Technol, 52, 68–74, 208–214. luchsinger s e, kropf d h, garcia-zepeda c m, hunt m c, marsden j l, rubio-canas e j, kastner c l, kuecker w g and mata t (1996), ‘Color and oxidative rancidity of gamma and electron beam irradiated boneless pork chops’, J Food Sci, 61(5), 1000–1005, 1093. luchsinger s e, kropf d h, garcia-zepeda c, hunt m c, stroda s l, marsden j l and kastner c l (1997a), ‘Color and oxidative properties of irradiated ground beef patties’, J Muscle Foods, 8(4), 445–464. luchsinger s e, kropf d h, chambers e, zepeda c m g, hunt m c, stroda s l, hollingsworth m e, marsden j l and kastner c l (1997b), ‘Sensory analysis of irradiated ground beef patties and whole muscle beef’, J Sensory Studies, 12, 105–126. lusk j l, fox j a, and mcilvain c l (1999), ‘Consumer acceptance of irradiated meat’, Food Technol, 53, 56–59.

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

129

lynch j a, macfie h j h and mead g c (1991), ‘Effect of irradiation and packaging type on sensory quality of chill-stored turkey breast fillets’, Int J Food Sci Technol, 26, 653–668. maidment d c f, dembny z and harding c (1999), ‘A study into the antibiotic effect of garlic Allium sativum on Escherichia coli and Staphylococcus albus’, Nutr Food Sci, 4, 170–172. mcclure p j, beaumont a l, sutherland j p and roberts t a (1997), ‘Predictive modelling of growth of Listeria monocytogenes. The effects on growth of NaCl, pH, storage temperature and NaNO2’, Int J Food Microbiol, 34, 221–232. mccormick k, han i y, acton j c, sheldon b w and dawson p l (2003), ‘D and z-values for Listeria monocytogenes and Salmonella Typhimurium in packaged low-fat ready-to-eat turkey bologna subjected to a surface pasteurization treatment’, Poultry Sci, 82, 1337–1342. mead p s, slutsker l, dietz v, mccaig l f, bresee j s, shapiro c, griffin p m and tauxe r v (1999), ‘Food related illness and death in the United States’, Emerging Infectious Diseases, 5(5), 607–625. merritt c jr., angelini p, wierbicki e and shuts g w (1975), ‘Chemical changes associated with flavor in irradiated meat’, J Agri Food Chem, 23, 1037–1043. millar s j, moss b w, macdougall d b and stevenson m h (1995), ‘The effect of ionizing radiation on the CIELAB color co-ordinates of chicken breast meat as measured by different instruments’, Int J Food Sci Technol, 30, 663–674. miyahara m (2002), ‘Effects of gamma ray and electron-beam irradiations on survival of anaerobic and facultatively anaerobic bacteria’, Kokuritsu Iyakuhin Shokuhin Eisei Kenkyusho Hokoku, 120, 75–80. morrissey p a, brabdon s, buckley d j, sheehy p j a and frigg m (1997), ‘Tissue content of alpha-tocopherol and oxidative stability of broilers receiving dietary alpha-tocopherol acetate supplement for various periods pre-slaughter’, Br Poultry Sci, 38, 84–88. mottram d s, wedzicha b l and dodson a t (2002), ‘Acrylamide is formed in the Maillard reaction’, Nature, 419, 448–449. muriana p m, quimby w, davidson c a and grooms j (2002), ‘Postpackage pasteurization of ready-to-eat deli meats by submersion heating for reduction of Listeria monocytogenes’, J Food Protec, 65, 963–969. murphy r y, duncan l k, driscoll k h, beard b l, berrang m b and marcy j a (2003a), ‘Determination of thermal lethality of Listeria monocytogenes in fully cooked chicken breast fillets and strips during postcook in-package pasteurization’, J Food Protec, 66, 578–583. murphy r y, duncan l k, driscoll k h, marcy j a and beard b l (2003b), ‘Thermal inactivation of Listeria monocytogenes on ready-to-eat turkey breast meat products during postcook in-package pasteurization with hot water’, J Food Protec, 66, 1618–1622. nam k c and ahn d u (2002a), ‘Carbon monoxide-heme pigment is responsible for the pink color in irradiated raw turkey breast meat’, Meat Sci, 60, 25–33. nam k c and ahn d u (2002b), ‘Mechanisms of pink color formation in irradiated precooked turkey breast meat’, J Food Sci, 67, 600–607. nam k c and ahn d u (2002c), ‘Effect of double-packaging and acid combination on the quality of irradiated raw turkey patties’, J Food Sci, 67(9), 3252–3257. nam k c and ahn d u (2003a), ‘Combination of aerobic- and vacuum-packaging to control color, lipid oxidation and off-odor volatiles of irradiated raw turkey breast’, Meat Sci, 63(3), 389–395. nam k c and ahn d u (2003b), ‘Effects of irradiation on meat color’, Food Sci Biotech, 12, 198–205. nam k c and ahn d u (2003c), ‘Use of antioxidants to reduce lipid oxidation and off-odor volatiles of irradiated pork homogenates and patties’, Meat Sci, 63, 1–8.

© Woodhead Publishing Limited, 2011

130

Processed meats

nam k c, ahn d u, du m and jo c (2001), ‘Lipid oxidation, color, volatiles, and sensory characteristics of aerobically packaged and irradiated pork with different ultimate pH’, J Food Sci, 66, 1225–1229. nam k c, min b r, park k s, lee s c and ahn d u (2003a), ‘Effects of ascorbic acid and antioxidants on the lipid oxidation and volatiles of irradiated beef patties’, J Food Sci, 68(5), 1680–1685. nam k c, min b r, yan h, lee e j, mendonca a, wesley i and ahn d u (2003b), ‘Effect of dietary vitamin E and irradiation on lipid oxidation, color, and volatiles of fresh and previously frozen turkey breast patties’, Meat Sci, 65, 513–521. nam k c, ko k y, min b r, ismail h, lee e j and ahn d u (2006), ‘Influence of rosemarytocopherol/packaging combination on the chemical quality and Listeria monocytogenes and Salmonella Typhimurium survival in restructured pork loins following electron irradiation’, Meat Sci, 74(2), 380–387. nam k c, min b r, ko k y, lee e j, cordray j and ahn d u (2008), ‘Packaging determines color and odor of irradiated ground beef’, Radiation Physics Research Progress, Aidan N. Camilleri (ed), Nova Publishers, 287–300. nanke k e, sebranek j g and olson d g (1998), ‘Color characteristics of irradiated vacuum-packaged pork, beef, and turkey’, J Food Sci, 63(6), 1001–1006. nanke k e, sebranek j g and olson d g (1999), ‘Color characteristics of irradiated aerobically packaged pork, beef, and turkey’, J Food Sci, 64, 272–276. niemira b a, fan x and sommers c h (2002), ‘Irradiation temperature influences product quality factors of frozen vegetables and radiation sensitivity of inoculated Listeria monocytogenes’, J Food Protec, 65, 1406–1410. olson d g (1998a), ‘Irradiation of food’, Food Technol, 52, 56–62. olson d g (1998b), ‘Irradiation processing’. In Murano E, Food Irradiation-A Sourcebook Meat and Poultry Irradiation Short Course. Ames, IA, Iowa State Univ. Press, 3–27. patterson r l and stevenson m h (1995), ‘Irradiation-induced off-odor in chicken and its possible control’, Br Poultry Sci, 36, 425–441. rababah t, hettiarachchy n, horax r, eswaranandam s, mauromoustakos a, dickson j and niebuhr s (2004), ‘Effect of electron beam irradiation and storage at 5 °C on thiobarbituric acid reactive substances and carbonyl contents in chicken breast meat infused with antioxidants and selected plant extracts’, J Agric Food Chem, 52, 8236–8241. ralovich b (1992), ‘Data for the properties of Listeria strains (a review)’, Acta Microbiol Hung, 39, 105–132. rico c w, kim g r, jo c, nam k c, kang h j, ahn d u and kwon j h (2009), ‘Microbiological and physicochemical quality of irradiated ground beef as affected by added garlic or onion’, Korean J Food Sci Anim Resour, 29(6), 680–684. rico-munoz e, bargiota e and davidson p m (1987), ‘Effect of selected phenolic compounds on the membrane-bound adenosine triphosphate of Staphylococcus aureus’, Food Microbiol, 4, 239–249. sadler g, chappas w and pierce d e (2001), ‘Evaluation of e-beam, gamma- and X-ray treatment on the chemistry and safety of polymers used with pre-packaged irradiated foods: a review’, Food Addit Contam, 18, 475–501. samelis j, bedie g k, sofos j n, belk k e, scanga j a and smith g c (2002), ‘Control of Listeria monocytogenes with combined antimicrobials after postprocess contamination and extended storage of frankfurters at 4 degrees C in vacuum packages’, J Food Protec, 65, 299–307. scharff r l (2010), ‘Health-related costs from foodborne illness in the United States’, Produce Safety project, available from: http://www.producesafetyproject. org/admin/assets/files/Health-Related-Foodborne-Illness-Costs-Report.pdf-1.pdf [accessed 5 July 2010].

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

131

seelinger h p r and jones d (1986), ‘Genus Listeria’. In Bergey’s Manual of Systemic Bacteriology, Sneath P H A, Mair N S, Sharpe M E, Baltimore, Williams and Wilkins, 1235–1245. shahidi f, pegg r b and shamsuzzaman k (1991), ‘Color and oxidative stability of nitrite-free cured meat after gamma irradiation’, J Food Sci, 56, 1450– 1452. shamsuzzaman k, lucht l and chuaqui-offermanns n (1995), ‘Effects of combined electron-beam irradiation and sous-vide treatments on microbiological and other qualities of chicken breast meat’, J Food Protec, 58, 497–501. shankaranarayana m l, raghavan b, abraham k o, natarajan c p, brodnitz h h (1974), ‘Volatile sulfur compounds in food flavors’ Crit Rev Food Sci Nutr, 4(3), 395–435. sommers c and boyd g (2005), ‘Elimination of Listeria monocytogenes from readyto-eat turkey and cheese tortilla’, J Food Protec, 68(1), 164–167. sommers c and fan x (2003a), ‘Gamma irradiation of fine-emulsion sausage containing sodium diacetate’, J Food Protec, 66, 819–824. sommers c h and fan x (2002b), ‘Antioxidant power, lipid oxidation, color, and viability of Listeria monocytogenes in beef bologna treated with gamma radiation and containing various levels of glucose’, J Food Protec, 65, 1750–1755. sommers c h, fan x, handel a p and niemira b a (2001), ‘Effect of ionizing radiation on beef bologna containing soy protein concentrate’, J Food Safety, 21, 151–165. sommers c h, niemira b a, tunick m and boyd g (2002a), ‘Effect of temperature on the radiation resistance of virulent Yersinia enterocolitica’, Meat Sci, 61, 323–328. sommers c h, kozempel m, fan x and radewonuk e r (2002b), ‘Use of vacuum-steamvacuum and ionizing radiation to eliminate Listeria innocua from ham’, J Food Protec, 65(12), 1981–1983. sommers c, fan x, niemira b a and sokorai k (2003a), ‘Radiation (gamma) resistance and postirradiation growth of Listeria monocytogenes suspended in beef bologna containing sodium diacetate and potassium lactate’, J Food Protec, 66, 2051–2056. sommers c h, fan x, handel a p and sokorai k b (2003b), ‘Effect of citric acid on the radiation resistance of Listeria monocytogenes and frankfurter quality factors’, Meat Sci, 63, 407–415. steccheni m i, del torre m, sarais p g, fuochi f, tubaro f and ursini f (1998), ‘Carnosine increases the radiation resistance of Aeromonas hydrophila in minced turkey meat’, J Food Sci, 61, 979–987. tanabe h, yoshida m and tomita n (2002), ‘Comparison of the antioxidant activities of 22 commonly used culinary herbs and spices on the lipid oxidation of pork meat’, Anim Sci J, 73, 389–393. tappel a l (1956), ‘Regeneration and stability of oxymyoglobin in some gamma irradiated meats’, Food Res, 21, 650–654. tarjan v (1990), ‘Sensitivity of Listeria monocytogenes to irradiation’, Acta Microbiol Hung, 37, 101–104. thakur b r and singh r k (1994), ‘Food irradiation – chemistry and applications’, Food Rev Int, 10, 437–473. thayer d w (1995), ‘Use of irradiation to kill enteric pathogens on meat and poultry’, J Food Safety, 15, 181–192. thayer d w and boyd g (1999), ‘Irradiation and modified atmosphere packaging for the control of Listeria monocytogenes on turkey meat’, J Food Protec, 62, 1136–1142. thayer d w and boyd g (2000), ‘Reduction of normal flora by irradiation and its effect on the ability of Listeria monocytogenes to multiply on ground turkey

© Woodhead Publishing Limited, 2011

132

Processed meats

stored at 7 degrees C when packaged under a modified atmosphere’, J Food Protec, 63, 1702–1706. thayer d w, boyd g and jenkins r k (1993), ‘Low-dose gamma irradiation and refrigerated storage in vacuum affect microbial flora of fresh pork’, J Food Sci, 58, 717–719, 733. thayer d w, boyd g, fox j b and lakritz l (1995), ‘Effects of NaCl, sucrose, and water content on the survival of Salmonella Typhimurium on irradiated pork and chicken’, J Food Protec, 58(5), 490–496. usda fsis (1986), ‘Irradiation of pork for control of Trichinella spiralis’, Federal Register, 51, 1769–1771. usda fsis (1992), ‘Irradiation of poultry products’, Federal Register, 57, 43588–43600. usda fsis (1999a), ‘Meat and poultry irradiation proposal’, USDA Food Safety and Inspection Service, available from: http://www.fsis.usda.gov/oa/background/irradprop.htm [accessed 8 July 2010]. usda fsis (1999b), ‘Irradiation of meat and poultry products, ionizing radiation as an additive in unrefrigerated meat food products, USDA Food Safety and Inspection Service, available from: http://www.fsis.usda.gov/Oa/topics/hotboned.htm [accessed 3 Aug, 2010]. vekiari s a, oreopoulou v, tzia c and thomopoulos c d (1993), ‘Oregano flavonoids as lipid antioxidants’, J Amer Oil Chem Soc, 70, 483–487. wen j, morrissey p a, buckley d j and sheehy p j a (1996), ‘Oxidative stability and α-tocopherol retention in turkey burgers during refrigerated and frozen storage as influenced by dietary tocopheryl acetate’, Br Poultry Sci, 37, 787– 792. who (1994), ‘Food irradiation’. In Safety and Nutritional Adequacy of Irradiated Food. Geneva, World Health Organization, 5–13. winne a d and dirinck p (1996), ‘Studies on vitamin E and meat quality. 2. Effect of feeding high vitamin E levels on chicken meat quality’, J Agric Food Chem, 44(7), 1691–1696. xiong y l, decker e a, robe g h and moody w g (1993), ‘Gelation of crude myofibrillar protein isolated from beef heart under antioxidant conditions’, J Food Sci, 58, 1241–1244. yang h s, lee e j, moon s h, paik h d and ahn d u (2011), ‘Effect of garlic, onion, and their combination on the quality and sensory characteristics of irradiated raw ground beef’, Anim Sci, 88, 286–291. yoon k s (2003), ‘Effect of gamma irradiation on the texture and microstructure of chicken breast meat’, Meat Sci, 63, 273–277. zhu m j, mendonca a and ahn d u (2004a), ‘Effect of temperature abuse on the quality of irradiated pork loins’, Meat Sci, 67, 643–649. zhu m j, mendonca a, min b, lee e j, nam k c, park k, du m, ismail h a and ahn d u (2004b), ‘Effects of electron beam irradiation and antimicrobials on the volatiles, color and texture of ready-to-eat turkey breast roll’, J Food Sci, 69(5), C382–C387. zhu m j, lee e j, mendonca a and ahn d u (2004c), ‘Effect of irradiation on the quality turkey ham during storage’, Meat Sci, 66(1), 63–68. zhu m j, mendonca a, lee e j and ahn d u (2004d), ‘Influence of irradiation and storage on the quality of ready-to-eat turkey breast rolls’ Poultry Sci, 83, 1462–1466. zhu m j, du, m, cordray j and ahn d u (2005a), ‘Control of Listeria monocytogenes contamination in ready-to-eat meat products’, Crit Rev Food Sci Food Safety, 4, 34–42. zhu m j, mendonca a, ismail h a, du m, lee e j and ahn d u (2005b), ‘Impact of antimicrobial ingredients and irradiation on the survival of Listeria

© Woodhead Publishing Limited, 2011

The use of irradiation in processed meat products

133

monocytogenes and quality of ready-to-eat turkey ham’, Poultry Sci, 84(4), 613–620. zhu m j, mendonca a, ismail h a and ahn d u (2008), ‘Effects of irradiation on survival and growth of Listeria monocytogenes and natural microflora in vacuumpackaged turkey hams and breast rolls’, Poultry Sci, 87, 2140–2145. zhu m j, mendonca a, ismail h a and ahn d u (2009), ‘Fate of Listeria monocytogenes in ready-to-eat turkey breast rolls formulated with antimicrobials following e-beam irradiation’, Poultry Sci, 88, 205–213.

© Woodhead Publishing Limited, 2011

6 Regulation of processed meat labels in the European Union M. Fogden, Agriculture and Horticulture Development Board, UK

Abstract: This chapter indicates and explains selected regulatory requirements that govern the labelling of processed meat and its products in the European Union. Key words: EU food law, food labelling, health claims, nutrition claims, food additives.

6.1 Introduction This chapter explains some aspects of the regulatory requirements governing food labelling within the European Union (EU). It has been prepared from selected extracts from relevant texts, and as always further reference must be made by readers as necessary and appropriate to the original texts (see Section 6.8 for references to the texts mentioned in this chapter) and related laws, guidance and administrative provisions. Readers will find a comprehensive list of EU legislation in Van der Meulen and van der Velde’s European Food Law Handbook (2008), albeit all such listings rapidly become dated as food law develops. To make an informed choice, purchasers of processed meat and its products need to know in advance what they will receive for their money, so the information provided by sellers must be sufficient and accurate to enable them to do so. However, there can be significant differences between the types and amounts of information that individual buyers seek or need, and sellers can be selective about what they wish to provide. Food law requires sellers to provide certain information based on purchaser expectations, administrative and judicial experience, and public policy. The area of food law is quite complex. This chapter is prepared merely as an overview of selected food law as specifically related to meat and meat products and consequently neither the author nor his employer can accept

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

135

any responsibility for any use that may be made of it. Specific advice from the author or another experienced consultant is likely to be helpful. 6.1.1 Background The EU comprises 27 Member States, varying very considerably in history, culture and wealth. These have come together in recent years, forming a polyglot Community aspiring to provide its citizens with an efficient food supply satisfying their diverse needs, demands and desires. Food labelling law assists significantly towards achieving this objective, enabling the rapid comparison of products from diverse origins based on consistent criteria while permitting additional truthful information to be provided to indicate particular attributes and enabling reasonable marketing of the product. These legal rules are simple in form while complex in interpretation and application. EU legislation comprises the Treaties, with subordinate Regulations and other Instruments providing detailed requirements. The Regulations are adopted by a Council of national ministers working with a Parliament of representatives elected on a popular basis, in cooperation with the EU bureaucracy, the Commission. This tripartite foundation, assisted by input from other institutions and interested parties, attempts to harmonise national legal diversities, and develops food law based on objective science. Relevant scientific advice is provided by the European Food Safety Authority (EFSA) from its offices in Parma (Italy), working with cooperating national agencies. There are three main types of subordinate instruments: Regulations, Decisions and Directives. Regulations are directly applicable in all the Member States, while Decisions apply directly to the individuals, companies or states mentioned in them. Directives indicate objectives which are to be achieved by the Member States, but individual states can choose how to implement them. As a result, Directives result in national measures that are frequently inconsistent with one another, to varying degrees, and which may not achieve the Community objectives (although they should conform to the spirit of the Directive). Consequently, Community food law is now largely adopted in the form of Regulations to avoid national differences that may distort the Community market. 6.1.2 International relations The food industry operates in a global market, and EU food law recognises this by contributing and adhering in principle to Codex Alimentarius recommendations unless they conflict with its own needs. The European institutions also develop bilateral relationships with other states to ensure that imports and exports of food are not unduly hindered while maintaining desirable levels of quality and control, including in relation to the labelling of the food.

© Woodhead Publishing Limited, 2011

136

Processed meats

6.2 The European Union (EU) general food law regulation The framework underlying more specific Community and national food law within the EU is Regulation 178/2002 (EU, 2002), which is intended to provide the basis for a high level of protection of consumers’ interests. It establishes common principles and responsibilities, and defines fundamental terms such as ‘food’ and ‘food law’. The latter includes laws, Regulations and administrative provisions, at Community or National level, applicable to all stages of the production, processing and distribution of food.

6.2.1 Responsibilities Article 17 of the Regulation places the primary responsibility on food business operators to ensure and verify that food complies with all relevant food law, including the rules on food labelling. The fundamental responsibility for making sure that food is properly labelled is not on the official control bodies in the Member States that police compliance with the law, although they have an important role in ensuring that food business operators meet their responsibilities, since investigations and enforcement action by official control authorities provide reassurance and correction.

6.2.2 Traceability Information provided on food labels must be accurate, precise, sufficient and credible if it is to be meaningful and useful. Traceability is required under the Regulation; this gives clarity and confidence to purchasers throughout the supply chain. It assists purchasers of food, themselves or through national authorities, to establish the truth of the information provided on a label, especially where this requires checking that information derived from earlier in the production and supply chain has not been corrupted, whether by accident or deliberately.

6.2.3 Protection of consumers’ interests Article 8 of the Regulation requires food labelling law to aid in the protection of the interests of consumers and to provide a basis for them to make informed choices in relation to the foods they consume. It aims to prevent fraudulent or deceptive practices, the adulteration of food, and any other practices which may mislead consumers to a material degree. In particular, Article 16 prohibits the labelling, advertising and presentation of food from misleading consumers. This includes any information which is made available about the food through any medium. Labelling relates to the parts of the packaging where information is provided, and the information itself, and similarly to a notice or other place where information may be provided about the food.

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

137

Food businesses need to promote their products in the marketplace. Branding takes numerous forms and is commonly a contributory factor to determining the nature of the labelling of any particular food. Labelling is important in building the business image. The branding may in itself provide reassurance about the quality and consistency of the food in the mind of a prospective purchaser. This is permissible under food labelling law provided it does not mislead.

6.2.4 Quality schemes It is noticeable in recent years that there has been a proliferation of quality schemes, and with this, many quality logos (labels) have appeared in the labelling of foods that comply with those schemes. It is by no means clear in some cases what qualities are being promoted by the use of these logos, although some schemes do provide an indication of this on the label, on their Internet websites or through promotional literature. Nevertheless, there is a risk that consumers could be misled into believing that some of these logos promise more than they actually deliver. See also Section 6.3.9. However, such claims are covered by food labelling law. By using a quality logo, or otherwise promoting the concept that food offered for sale is compliant with the specifications of a quality scheme, the supplier is asserting that this is truly the case. Consequently, the normal provisions against the provision of false or misleading information automatically come into play. Additionally, if such assertions are made by those who do not actually participate in the relevant scheme, there may be grounds for an action in intellectual property law, for example in relation to copyright, trade marks or passing-off, available to the scheme owner as well as proceedings being taken by the appropriate authorities.

6.3

Labelling and claims rules

While the General Food Law Regulation provides a framework, the specific rules on food labelling have been provided in a series of measures, generally in the form of directives. For some years, the Community institutions have been negotiating towards the adoption of a replacement text in the form of a ‘Regulation on the provision of food information to consumers’. This updated description of food labelling recognises that nowadays information is often provided other than on labels or in addition to labelling. This broadening is welcome and should lead to a better control structure, albeit a significant restructuring of labelling law as we know it is likely to result in less certainty until all parties concerned have resolved the interpretative issues that will inevitably come to light.

© Woodhead Publishing Limited, 2011

138

Processed meats

6.3.1 Food labelling directive The majority of the rules provided by Directive 2000/13 (EU, 2000a) are to be found, in some cases with amendments, in the proposal for a Regulation on the provision of the food information to consumers. Responsibility for the proper labelling of food lies with the food business operator. The basis for food labelling law, as indicated above, is to ensure that certain basic information is properly presented so that intending purchasers can make an informed choice. This provides consistency and avoids inadequacy of information. Certain information must be provided in an easily understood language to consumers in the labelling of pre-packaged foods. These include the following (in summary only – the requirements are detailed and complex): • The product name, which may be a prescribed name (frequently linked with production or compositional standards), a customary name or a name that is sufficiently specific to indicate the true nature of the product. The name must include or be accompanied by particulars as to the physical condition of the food or the specific treatment which it has undergone, if omission of this information might be misleading. • A list of ingredients, except for single ingredient foods or specified exceptions, generally in descending order of proportion of each ingredient. Ingredients include, with certain exceptions, any substance, including additives, that are used in the manufacture or preparation of a food and are still present in the finished product, even if in an altered form. Where an ingredient of a food is itself prepared from several ingredients, each of these counts as an ingredient of the food in question. • A quantitative ingredient declaration (QUID) for an ingredient (or category of ingredients) used in the manufacture or preparation of a food. This must be stated, as a percentage: • if the ingredient (or category) appears in the name under which the food is sold or is usually associated with that name by the consumer; or • where the ingredient or category of ingredients concerned is emphasised on the labelling in words, pictures or graphics; or • where the ingredient or category of ingredients concerned is essential to characterise a foodstuff and to distinguish it from products with which it might be confused because of its name or appearance. A QUID is normally provided for each meat used in a meat product. This must appear either in or immediately next to the name under which the food is sold or in the list of ingredients in connection with the ingredient (or category) in question. Fat or connective tissue derived from meat must be indicated separately in the list of ingredients if it is in excess of the maximum proportions permitted under Annex I of Directive 2000/13. • The quantity of the food. This is relevant to value, since price/kg comparisons can be made. Directive 98/6/EC (EU, 1998) provides the rules

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

•

• • • •

• • •

• •

139

for price indications, generally requiring both the selling price and the unit price (e.g. £/kg) to be stated, unless these are identical. The date of minimum durability, provided in the prescribed manner. This may be a ‘best before date’ or, in the case of foods that are highly perishable because of their microbiological sensitivity, a ‘use by date’. It is an offence to sell food after its use by date, which relates to food safety, whereas the best before date relates only to the quality of the product. There is no requirement for a ‘sell by’ date, which may additionally be present. Any special storage conditions. Any special conditions of use. The name or business name and the address of the manufacturer or packager, or of a seller established within the Community. The origin or provenance, if omission of this might mislead the consumer to a material degree as to the true origin or provenance. See also Section 6.6.1. Instructions for use, if it would be impossible to make appropriate use of the food without such instructions. An indication of any irradiation that has been received. The category name and the name or ‘E’ serial number of most additives, unless the presence serves no technological purpose in the food and is solely due to carry-over from an ingredient. The (possible) presence of prescribed allergens, even if present in minute quantities (see Section 6.3.7). Nutritional information, where required.

The requirements for food that is not pre-packaged vary among the Member States. They may require all or some of the above particulars. 6.3.2 Lot marking Directive 89/396/EEC (EU, 1989) provides the rules on labelling prepackaged food with batch identification information. Where a date of minimum durability or ‘use by’ date including the day and month (in that order) is present, there is no need to provide a separate batch indication. Article 14(6) of the General Food Law Regulation prescribes that where any unsafe food is part of a batch, lot or consignment of similar food, the whole of that batch, lot or consignment is to be presumed to be unsafe unless it is assessed and there is good evidence that this is not the case. 6.3.3 Origin marking of meat products It is generally the case that the origin of a processed product is the place where the last substantial transformation took place, and this has led to numerous complaints that the consequences can be misleading. For example, pork may be produced in a Belgian slaughterhouse, from a pig raised in

© Woodhead Publishing Limited, 2011

140

Processed meats

France and born in Spain. Under the general principle the last substantial transformation clearly took place when the pig was slaughtered, and the pork can properly be described as Belgian, albeit it may be that the pig spent all but the last hours of its life outside Belgium. If that pork is then moved to the United Kingdom and converted into bacon, the bacon is properly described as British. To deal with this, the Food Standards Agency in the United Kingdom produced guidance that an appropriate description of the bacon would not only indicate that proper origin description, but should also indicate the places where the pigs were born, reared and slaughtered, along similar lines to those of the beef labelling regime (see below). The Agency promoted this principle widely throughout the EU, but at the time of writing it remains uncertain whether this will be incorporated into the proposed Regulation on the provision of food information to consumers, which is expected to replace the current Food Labelling Directive and other texts after a very long period of gestation. One consequence of the substantial transformation rule is that meat imported from third countries and converted into products within the EU may well be indicated to consumers only as ‘produce of the EU’ or as produce of a particular Member State. Consumers may be misled by this into a belief that the meat originated there. This should not have any adverse hygiene consequences, since the meat could lawfully originate only from premises certified as being up to EU standards. However, the emotional prejudice of EU consumers in favour of produce from their own state results in challenges which have a limited scientific basis. This undermines also the principle of the Single Market and indeed, the beef labelling regime below was introduced largely for such reasons in the context of bovine spongiform encephalopathy (BSE) in continental Europe, and this strongly renationalised the beef market of the Community.

6.3.4 Labelling of beef and veal Following the outbreak of BSE in continental Europe, a number of control measures were introduced. Regulation 1760/2000 (EU2000b) was a lateral measure demanding detailed origin labelling for beef and veal in addition to the normal food labelling requirements. These rules only apply to beef and veal, and these meats when minced. They do not apply to other beef or veal products, nor to any other meats, although it is likely that certain of the concepts will be applied to other meats. The rules require beef and veal to be labelled with a traceability code and with specified origin information in a prescribed format. This comprises the Member State(s) where the animals were born, raised and slaughtered, and where the meat was cut. Additionally, the premises of slaughter and cutting must be identified. Modified rules apply to the meats when minced and to meats originating outside the EU.

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

141

Specific labelling for veal has been added by Regulation 700/2007 (EU, 2007a), based on the age at slaughter, which must be specified in labelling as ‘up to 8 months’ or ‘from 8 to 12 months’, although a code (V and Z respectively) can be used in the supply chain except for sale to the final consumer. Additionally, prescribed names must be used. For example, in the UK, ‘veal’ will be the name compulsorily used for veal from younger animals, but ‘beef’ for older meat. In Ireland, the terms will be ‘veal’ and ‘rosé veal’ respectively. There are consequently opportunities for confusion in trade between these states. Directive 2000/101/EC (EU, 2000c) amended the food labelling directive, defining meat as an ingredient of another food as the ‘skeletal muscles (including the diaphragm and the masseters, but excluding heart, tongue and the tail) of mammalian and bird species recognised as fit for human consumption with naturally included or adherent tissue.’ It limited this by prescribing maxima for the total fat and connective tissue contents. This established how the meat content of a compound food was to be determined. Various meat content calculators were established to assist with this, giving different values depending on the parameters used for the average content of components (e.g. protein, fat) in the various cuts of meat that might be used. Additionally, lesser used cuts of meat were not always incorporated in the calculator database. The prescribed maxima for fat and connective tissue (calculated based on the ratio between the collagen [i.e. hydroxyproline × 8] and protein contents) are shown in Table 6.1. Pursuant to this definition, the Directive provided that any fat or connective tissue in excess of these permitted amounts must be listed separately in the list of ingredients. This provision only applies where meat is included as an ingredient, and does not apply to mechanically recovered/separated meat. These limits do not apply to the supply of meat as such, although they may be used by official control authorities as a basis for challenge that such meat is not of an appropriate quality for sale without further description, for example where minced beef has a fat content greater than 25%. The calculation of added water content may be necessary to establish compliance with declared contents in, for example, cured pork products such as bacon.

Table 6.1 Maximum fat and connective tissue contents in meat Species Porcines Birds and rabbits Mammals (other than porcines and rabbits) and mixtures of species with mammals predominating)

Fat (%)

Connective tissue (%)

30 15 25

25 10 25

© Woodhead Publishing Limited, 2011

142

Processed meats

The UK Food Standards Agency reported (FSA, 2007) that in a survey of meat products, the meat content was calculated using three separate methods. Two were recipe-based calculations: the FSA method is based on the manufacturer’s visual lean estimation of meat ingredients by eye and reference to typical values of fat and connective tissue; whereas the CLITRAVI (Liaison Centre for the Meat Processing Industry in Europe) method is based on analytical values of fat and connective tissue in the meat ingredients. The third method (Stubbs and More calculation) (Stubbs and More, 1919), which is limited to single species products, is based on analysing the meat product for nitrogen and fat and using agreed nitrogen factors to calculate the meat content. The latter method has been much refined since the original procedure was published. Overall, the survey indicated that the manufacturers sampled were declaring their meat contents accurately. This was confirmed by comparing the manufacturer’s meat declaration to the meat content determined by the CLITRAVI and Stubbs and More calculations, taking into account the analytical tolerances. Declaring more meat than is actually present misleads consumers, but only 3% or 4% (depending on the calculation used) of the samples over-declared the amount of meat. If the tolerance was increased to 10%, only 1% of the products declared more meat than was calculated. In approximately 40% of the products, the manufacturer’s meat contents were under-declared, which could disadvantage the manufacturer. The results showed that the FSA calculation accords reasonably well with the CLITRAVI one, which is the EU recommended method. The Stubbs and More calculation, which is used by UK official control laboratories (public analysts, a position formerly held by the author), also agreed reasonably well with the other calculations. However, using the Stubbs and More calculation can occasionally lead to under-estimation of the meat content of a meat product. If possible, meat content determination by the CLITRAVI method in-factory is recommended in such cases. 6.3.5 Nutrition labelling Directive 1990/496 (EU, 1990) currently defines the rules for nutrition labelling, which is compulsory if a nutrition or health claim is being made. Any voluntary labelling with nutrition information triggers the need to comply with this Directive. Nutrition information is that relating to energy value, protein, carbohydrate, fat, fibre, sodium/salt, vitamins and minerals. Only specified minerals and vitamins may be indicated. As a minimum, the proportions of energy, protein, carbohydrate, fat (the ‘Big 4’) must be provided in a prescribed format. Alternatively, those can be given together with the proportions of sugar, saturated fats, fibre and sodium (the ‘Big 8’). There is clear consumer uncertainty about the provision of information on sodium rather than salt and the relationship between these. Additionally, mineral and vitamin levels may need to be quantified on the label.

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

143

6.3.6 Nutrition and health claims The food labelling directive (2000/13) (EU, 2000a) required the Council to develop a list of health and nutrition claims, including prohibitions on use and conditions of use, as appropriate. This was adopted as Regulation 1924/2006 (EU, 2006d) and applies to communications to consumers and mass caterers, including through advertising and labelling. A claim is defined as any message or representation, which is not mandatory under Community or national legislation, including pictorial, graphic or symbolic representation, in any form, which states, suggests or implies that a food has particular characteristics. This is divided into two classes: • Health claims are claims that state, suggest or imply that a relationship exists between a food category, a food or one of its constituents and health. • Nutrition claims are claims which state, suggest or imply that a food has particular beneficial nutritional properties due to the amount of energy (calorific value) it provides or does not provide; and/or the quantity of nutrients or other substances it contains or does not contain. Health claims and nutrition claims can be made only if they satisfy the requirements of this Regulation. Such claims must not be false, ambiguous or misleading; give rise to doubt about the safety or nutritional adequacy of other foods; or encourage or condone excess consumption of a food. They may not state, suggest or imply that a balanced and varied diet cannot provide appropriate quantities of nutrients in general. Nor may they refer to changes in bodily functions that may give rise to or exploit fear in the consumer. Control of nutrition and health claims is to be based on nutrient profiles established by the Commission for categories of food which will be associated with conditions which must be met if such claims are to be made. These are to be based on the quantities of nutrients and other substances contained in the food; the role and importance of the food and its contribution to the diet of the population in general, or of particular risk groups; and the overall nutritional composition of the food and the presence of nutrients that are scientifically recognised as having an effect on health. They are currently being developed in scientific cooperation with the EFSA, although this task is proving to be somewhat complex and controversial. Certain fundamental conditions are specified concerning the nutrient or substance concerned. These are: • its presence, absence or reduced content must have been shown to have a beneficial nutritional or physiological effect, and the quantity present (or its absence) must be able to produce the claimed effect; • if present, it must be in a significant quantity in an amount of the food that can reasonably be expected to be consumed; and in a form that is available to be used by the body.

© Woodhead Publishing Limited, 2011

144

Processed meats

Other fundamental conditions are that: • the average consumer must be expected to understand the beneficial effects as expressed in the claim; • the claim must refer to the food ready for consumption in accordance with the manufacturer’s instructions; • nutrition information must be provided on labels in the ‘Big 8’ format in accordance with Directive 90/496, for both health and nutrition claims, together with the amount(s) of any substance(s) relating to the claim but not contained in the ‘Big 8’ statement; and • the conditions in this Regulation generally applicable to health claims or nutrition claims, as appropriate, must be met, as well as any specific conditions relating to the claim. Numerous other provisions are contained within this Regulation, including the mechanism for applying for the authorisation and registration of claims based on a detailed and objective scientific evaluation. An Annex provides conditions which must be met for the use of certain common nutrition claims: low energy, energy-reduced, energy-free, low fat, fat-free, low saturated fat, saturated fat-free, low sugars, sugar-free, with no added sugars, low sodium/salt, very low sodium/salt, sodium-free or saltfree, source of fibre, high fibre, source of protein, high protein, claims relating to the presence of vitamins and/or minerals, claims for increased or reduced quantities of nutrients, light/lite and naturally/natural.

6.3.7 Allergen labelling Specific controls introduced by Directive 2003/89 (EU, 2003c) require an indication of the presence of specified allergens in food, whether they have been introduced as an ingredient or used in the preparation of an ingredient, unless they are specifically exempted. The list of such ingredients includes very common ingredients in meat products (see Table 6.2). The dilemma of allergy implications on processed meat manufacture has become quite significant as the range of available ingredients (that were once ingredients of choice) is now significantly reduced and there is a pressure to develop an alternative novel range of adjuncts, these having their own problems of regulatory approval and reluctant consumer acceptance. Contrariwise, the meat processing industry is increasing the range of naturally derived ingredients by utilising carefully prepared derivatives of meat. Regrettably but not surprisingly, this has resulted in misuse of these by unscrupulous manufacturers to enhance apparent meat contents and to obscure their failure to comply with regulatory requirements. This in turn has led to substantial advances in analytical and enforcement procedures, as these abuses have been met and dealt with.

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

145

Table 6.2 Allergens Ingredient

Comments

Cereals* containing gluten

Comprises wheat, rye, barley, oats, spelt, kamut (and their hybrids)

Crustaceans* Eggs* Fish* Peanuts* Soybeans* Milk* Nuts*

Includes lactose Comprises almonds, hazelnuts, walnuts, cashew nuts, pecan nuts, Brazil nuts, pistachio nuts, macadamia nuts and Queensland nuts

Celery* Mustard* Sesame seeds* Sulphur dioxide and sulphites

In concentrations exceeding 10 mg/kg or 10 mg/l (as SO2)

Lupin* Molluscs* * Products of these ingredients are also caught by the allergen rules.

6.3.8 Compulsory labelling indications Directive 2008/5 (EU, 2008a) requires specific statements to be presented on labels for foods whose durability has been extended by the use of authorised packaging gases (‘packaged in a protective atmosphere’), or which contain sweeteners, polyols, or liquorice (as such or as its active components).

6.3.9 Protected food names In Community terms, protection of food names is enabled through regulations which provide for the registration of products having particular qualities with the Commission or via national authorities. In particular, where the name of a product implies the presence of qualities related to the geography of its production or processing, this can be protected under Regulation 510/2006 (EU, 2006b) as a Protected Designation of Origin (PDO) or Protected Geographical Indication (PGI). Similarly, for product names relating to traditional product qualities that do not have a geographic link, Regulation 509/2006 (EU, 2006a) provides a protective mechanism for Traditional Specialities Guaranteed (TSG). In each of these cases, a specific Community logo is to be used in conjunction with the name. Similarly, a Community logo is associated by Regulation 834/2007 (EU, 2007b) with the concept of organic products, whose qualities are inherently derived from

© Woodhead Publishing Limited, 2011

146

Processed meats

the naturalness of the production system. Such logos enhance the image of the products concerned. While overall product quality will be derived from all the qualities possessed by a product, the possession of specific qualities that have been registered does not in itself imply that the overall quality of the product is better than that of a similar product which does not have the qualities recognised at EU level. Indeed, some properly registered products having consistent and verifiable properties derived from the geography of their production were known when registered to have an overall quality significantly lower than the norm. The use of such logos, particularly if used in unclear advertising or labelling, has the potential to mislead consumers into thinking that they represent a higher quality of product than the norm. On the other hand, many foods, including meat products such as Parma ham and Melton Mowbray pork pies, have a substantial reputation for high quality which complements their ‘qualities’ registration.

6.3.10 Hygiene labelling One of the more difficult and irritating aspects of trying to comply with EU food labelling law is that while most of it is to be found in instruments dedicated to the topic as such, scraps appear in remote places. For example, a small amount of hygiene-related labelling relevant to meat products is provided in hygiene Regulation 853/2004 (EU 2004) (‘H2’). Article 5 of H2 requires labelling of products of animal origin with a health mark or an identification mark which shows that the product was handled in an establishment which has been approved as being compliant with the requirements of this Regulation. These marks can cause confusion, because they incorporate an indication of the state where the handling took place and this may be mistaken by consumers as an indication of the origin of the meat present in the product. Although not labelling per se, there are also documentation requirements relating to the identification and traceability of products in the Regulation. Buried in the depths of Annex III is another hygiene-related requirement that packaged minced meat from poultry or solipeds (horses, etc.) and meat preparations containing mechanically separated meat must bear a notice that they should be cooked before consumption – but only if that is specifically required by national rules. There are also labelling requirements for packages of gelatine and collagen. In general, there has been a clear shift in regulatory responsibility in recent years placing the burden firmly on the food business operator, who should now be able to prove systematic compliance and due diligence in confirming the effectiveness of the relevant systems. This is imperative in relation to food hygiene and food safety (Woodhead, 2010), and also applies to food labelling and other areas of food law.

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

147

6.4 Other measures Various EU legal instruments require labelling of particular meat products or ingredients to comply with specific rules.

6.4.1 Poultry meat marketing standards Article 1 of Regulation 2008/543 (EU, 2008b) defines various types of poultry carcases, poultry cuts and foie gras, and prescribes the names under which these are to be marketed. These are translated into other Community languages in Annexes. Other articles refine these requirements, including restricting the descriptive terms that may be used to indicate the production method (e.g. ‘Traditional free range’). Article 5 prohibits the use of the prescribed names for other products if such use might materially confuse consumers. Pre-packaged poultry meat must be labelled with its class and condition, the recommended storage temperature and the registered number of the slaughterhouse or cutting premises. Labelling with a ‘use by’ date is prescribed for fresh poultry meat, which must bear a price and unit price at the retail stage. Poultry meat imported from third countries must bear an indication of the country of origin.

6.4.2 Additives Food additives, as defined in Regulation 2008/1333 (EU, 2008c), are any substances not normally consumed as a food in themselves and not normally used as a characteristic ingredient of food, whether or not they have nutritive value, the intentional addition of which to food for a technological purpose in the manufacture, processing, preparation, treatment, packaging, transport or storage of such food results, or may be reasonably expected to result, in them or their by-products becoming directly or indirectly a component of such foods. A number of exclusions apply. Additives are incorporated into processed meat and its products for technological purposes, including through providing improvements in product safety, appearance and texture, and in the production, handling, storage and display of products. Twenty-two categories of additive activity (e.g. antioxidant, preservative, emulsifier) specified in Directive 2000/13 have been extended to 26 functional classes in Regulation 2008/1333. Use of additives arouses negative emotional reactions in some consumers. To assist in making an informed choice and because adverse reactions can be provoked in sensitive individuals by some additives, almost all of them must be specifically indicated in lists of ingredients, preceded by the activity category which the additive performs in the food. Where it serves more than one such purpose, only the principal category need be indicated. From 20 July 2010, Regulation 2008/1333 requires the statement ‘[name or E number of the colour(s)]: may have an adverse effect on activity and

© Woodhead Publishing Limited, 2011

148

Processed meats

attention in children.’ to be presented in the labelling of foods containing any of six colours: Allura red, Carmoisine, Ponceau 4R, Quinoline yellow, Sunset yellow and Tartrazine. Table 6.3 may assist in the functional classification of additives, although it must be remembered that the legal requirement is to indicate the specified category (if any) of the principal effect of the additive in the product. The declarable category of a particular additive may therefore be different in different products. Detailed labelling requirements on additives sold to food business operators preparing or manufacturing foods must provide sufficient information in clear and easily understandable terms to ensure that users are able to use the additives properly.

6.4.3 Genetically modified (GM) ingredients Genetic modification of food ingredients attracts negative responses from many European consumers, unlike elsewhere in the world, fed by pressures from politicians and the media. These appear (rightly or wrongly) to place little reliance on the extensive scientific evaluation necessary before a GM ingredient or GM food can be marketed within the Community. The international availability of certain cereals and similar ingredients that do not contain any GM component is reducing, and this inevitably leads to increased prices. Regulations 1829/2003 and 1830/2003 (EU, 2003a, b) require a clear indication that an ingredient or a food is or contains GM material to be incorporated into the labelling of ingredients or food, such that a food business operator, consumer or mass caterer can readily ascertain that the product is genetically modified. The labelling must also make it clear if the food differs from its conventional counterpart in terms of its composition, nutritional value or intended use, or if there may be ethical, health or religious consequences. Similar labelling is needed where ingredients or foods have been irradiated.

6.4.4 Contaminants: pesticide, herbicide and veterinary residues There are no specific labelling requirements in relation to the presence of contaminants and other residues in foods and their ingredients, although detailed labelling requirements apply to the packs of the herbicides, pesticides and veterinary medicines themselves. For example, contaminants are controlled under Regulation 315/93 (EU, 1993). They are substances which are present in food as a result of the production (including operations carried out in crop husbandry, animal husbandry and veterinary medicine), manufacture, processing, preparation, treatment, packing, packaging, transport or holding of the food, or as a result of environmental contamination,

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Substances which increase the acidity of a foodstuff and/or impart a sour taste to it. Substances which alter or control the acidity or alkalinity of a foodstuff. Substances which reduce the tendency of individual particles of a foodstuff to adhere to one another. Substances which prevent or reduce foaming. Substances which prolong the shelf-life of foods by protecting them against deterioration caused by oxidation, such as fat rancidity and colour changes. Substances which contribute to the volume of a foodstuff without contributing significantly to its available energy value. Substances used to dissolve, dilute, disperse or otherwise physically modify a food additive or a flavouring, food enzyme, nutrient and/or other substance added for nutritional or physiological purposes to a food without altering its function (and without exerting any technological effect themselves) in order to facilitate its handling, application or use. Substances which add or restore colour in a food, and include natural constituents of foods and natural sources which are normally not consumed as foods as such and not normally used as characteristic ingredients of food. Preparations obtained from foods and other edible natural source materials obtained by physical and/ or chemical extraction resulting in a selective extraction of the pigments relative to the nutritive or aromatic constituents are colours. Substances which make it possible to form or maintain a homogeneous mixture of two or more immiscible phases such as oil and water in a foodstuff. Substances which convert proteins contained in cheese into a dispersed form and thereby bring about homogeneous distribution of fat and other components. Substances which make or keep tissues of fruit or vegetables firm or crisp, or interact with gelling agents to produce or strengthen a gel. Substances which enhance the existing taste and/or odour of a foodstuff.

Acids Acidity regulators Anti-caking agents Anti-foaming agents Antioxidants

Flavour enhancers

Firming agents

Emulsifying salts

Emulsifiers

Colours

Carriers

Bulking agents

Description

Functional classes

Functional class

Table 6.3

© Woodhead Publishing Limited, 2011

Substances, other than emulsifiers, which are added to flour or dough to improve its baking quality. Substances which make it possible to form a homogeneous dispersion of a gaseous phase in a liquid or solid foodstuff. Substances which give a foodstuff texture through formation of a gel. Substances which, when applied to the external surface of a foodstuff, impart a shiny appearance or provide a protective coating. Substances which prevent foods from drying out by counteracting the effect of an atmosphere having a low degree of humidity, or promote the dissolution of a powder in an aqueous medium. Substances obtained by one or more chemical treatments of edible starches, which may have undergone a physical or enzymatic treatment, and may be acid or alkali thinned or bleached. Gases other than air, introduced into a container before, during or after the placing of a foodstuff in that container. Substances which prolong the shelf-life of foods by protecting them against deterioration caused by microorganisms and/or which protect against growth of pathogenic microorganisms. Gases other than air which expel a foodstuff from a container. Substances or combinations of substances which liberate gas and thereby increase the volume of a dough or a batter. Substances which form chemical complexes with metallic ions. Substances which make it possible to maintain the physico-chemical state of a foodstuff; stabilisers include substances which enable the maintenance of a homogeneous dispersion of two or more immiscible substances in a foodstuff, substances which stabilise, retain or intensify an existing colour of a foodstuff and substances which increase the binding capacity of the food, including the formation of cross-links between proteins enabling the binding of food pieces into re-constituted food. Substances used to impart a sweet taste to foods or in table-top sweeteners. Substances which increase the viscosity of a foodstuff.

Flour treatment agents Foaming agents

Sweeteners Thickeners

Sequestrants Stabilisers

Propellants Raising agents

Preservatives

Packaging gases

Modified starches

Gelling agents Glazing agents (including lubricants) Humectants

Description

Continued

Functional class

Table 6.3

Regulation of processed meat labels in the European Union

151

but which have not been added intentionally. Extraneous matter, such as insect fragments and animal hair, is not considered as contaminant. The Regulation prohibits the marketing of food containing a contaminant in an amount which is unacceptable from the public health viewpoint and in particular at a toxicological level. It further requires contaminant levels to be kept as low as can reasonably be achieved by following good practices. Regulation 1881/2006 (EU, 2006c) prescribes specific limits for various contaminants: nitrate, mycotoxins, lead, cadmium, mercury, 3monochloropropane-1,2-diol (3-MCPD), dioxins and polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons. Food business operators and consumers should therefore be confident that the food and ingredients they purchase are safe. Food business operators should note and abide by any labelling on ingredients which specifies maximum incorporation rates, since these may be important not only to ensure appropriate use but could also be intended to provide necessary dilution of contaminants or other residues such that the final product will be safe. One area where additive/residue rates are controlled is that of nitrites (and nitrates) in cured meats, under Directive 95/2/EC (EU, 1995) as amended by Directive 2006/52/EC (EU, 2006e) pending their transfer under Regulation 2008/1333 (EU, 2008c). The provisions are too complex to be summarised in this work but it is notable that the use of these preservatives is under pressure to be further restricted. Their action in meat products is multifunctional. Any such further restriction intended to minimise the potential for carcinogenic effects must be balanced carefully against the use of these compounds to prevent botulism, and it is important that the limitation of these additives does not lead to increased consumer risks. There is consequently a labelling issue, since consumers would need to be informed clearly about any decrease in the level of safety. Providing such information would require sensitivity to avoid creating unnecessary concern while providing transparent advice.

6.5 Codex Alimentarius (‘food code’) Codex, as it is commonly known, is an international organization providing standards for international trade in food. It was set up by the Food and Agricultural Organisation (FAO) and World Health Organisation (WHO), has 181 members, and operates through committees of countries (representing over 98% of the global population), which benefit from input by nongovernmental organisations (NGOs) having relevant strengths, such as the European Food Law Association. Codex currently operates over 200 standards, nearly 50 codes of practice and about 60 guidelines. It has undertaken over 1000 evaluations of additives and contaminants and set more than 3000 maximum residue limits (MRLs) for pesticides and veterinary medicines. These have all been achieved through international co-operation.

© Woodhead Publishing Limited, 2011

152

Processed meats

The standards include labelling provisions, individually expanding upon Codex STAN 1, the General Standard for the Labelling of Prepackaged Foods (Codex 1, 1985/2008). This provides a range of fundamental rules, which with the additional product-specific labelling rules, provide a practical foundation for the labelling of food in international trade, including that involving EU Member States. Other standards provide general labelling rules for use in particular situations, such as where there are special medical circumstances. 6.5.1 Influence of Codex Codex standards are not legally binding on businesses, although they can be specifically introduced as terms into contracts, nor must Codex members implement them into their regulatory or administrative regimes, for that would impinge upon their sovereignty. However, individual states can and frequently do voluntarily choose to incorporate Codex standards, wholly or partly, into their legally binding food law requirements. Within the EU, Codex standards are ordinarily incorporated into the regulatory structure, or at least will be taken into consideration as this is developed, following Article 5(3) of Regulation 178/2002 (EU, 2002). The Court of Justice has used relevant standards to limit the interpretative scope of Member States where the Community legislation is not entirely clear.

6.6 Provision of food information to consumers Food labelling in the Community has been under review for many years. Many observers, including the author, suggested that the 2000 Directive was merely a temporary measure which largely regurgitated provisions dating from 1979, pending further negotiations on effectively updating the rules. The 1979/2000 requirements have stood the test of time and are well understood by food businesses, food lawyers and food authorities. Any substantial changes are likely to lead to uncertainty until a similar level of understanding and agreement is achieved. The proposed Regulation on the provision of food information to consumers (EU, 2008d) is intended to update and extend the food labelling directive; it would come into practical effect within a few years of adoption. The title itself demonstrates the perceived need to cover the vastly wider range of mechanisms available nowadays for transmitting information about food to consumers, rather than just by labelling and presentation (and of course through advertising). The Internet has resulted in many opportunities for improved and/or more efficient communication, but also threats that such information could be presented in ways which were not able to be controlled easily or adequately. Certain aspects of the proposal may be significantly modified from the originally published text prior to adoption of the regulation, following further negotiations between the Community

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

153

institutions and dialogue with consumer, industry and enforcement representatives. Two examples of the proposed changes are indicated: Origin labelling and nutrition labelling. 6.6.1 Origin labelling Where a voluntary indication of origin is provided for a food then, without prejudice to any compulsory labelling requirements, if the country of origin or the place of provenance of the food is not the same as that of its primary ingredient(s), the country of origin or place of provenance of those ingredient(s) will also have to be given. For meat, other than beef and veal (see Section 6.3.4), the indication of the country of origin or place of provenance will only be able to be given as a single place if the animals have been born, reared and slaughtered in the same country or place. Otherwise, information on each of the places of birth, rearing and slaughter will need to be given. This would be a significant change from the position under Directive 2000/13/EC (EU, 2000a) where the general rule is laid down that an indication of origin is only required where it would be misleading not to do so, still the proposed position for foods not containing meat. 6.6.2 Nutrition labelling The proposal suggests that nutrition labelling should be mandatory and based on five or six compulsorily indicated parameters, rather than the current four or eight. These would be energy value; fat; saturates; carbohydrates, with specific reference to sugars; and salt. Additionally, a number of other nutrients could be declared, i.e. trans-fats, monounsaturates, polyunsaturates, polyols, starch, fibre, protein and specified minerals and vitamins. Sugars and saturates have thus been promoted, and protein demoted, presumably in response to diet and health (obesity) concerns. 6.6.3 Further delay The history of the proposed food information regulation has been one of slow and erratic progress. At the time of writing it has again faltered, this time awaiting the election of a new European Parliament; it can be assumed that it will be another year or more before the new regulations will be adopted. Consumers must therefore continue to wait for these laws which will require labels to bear improved information on the nutritional content of processed foods, and in a more consistent manner.

6.7 Sources of further information and advice Kirk, R and Sawyer, R (1991), Pearson’s Composition and Analysis of Foods, 9th ed., London, Longman Publishing Group.

© Woodhead Publishing Limited, 2011

154

Processed meats

Rowell, R et al. (editors) (2010), Butterworths Law of Food and Drugs, London, Reed Elsevier (UK) Ltd. Van der Meulen, B and van der Velde, M (2008), European Food Law Handbook, Wageningen (NL), Wageningen Academic Publishers. For Codex texts, see http://www.codexalimentarius.net/web/standard_list. do?lang=en EU legal instruments are available at http://eur-lex.europa.eu/en/index. htm. Many have been amended but the current status and often a consolidated text can be found by accessing the bibliography and consolidated texts provided.

6.8 References codex 1 (1985, as last amended 2008), General Standard for the Labelling of Prepackaged Foods, Rome, Codex Alimentarius Commission. eu (1989), Council Directive 89/396/EEC of 14 June 1989 on indications or marks identifying the lot to which a foodstuff belongs. OJ L 186, 30.6.1989, p. 21. eu (1990), Council Directive 90/496/EEC of 24 September 1990 on nutrition labelling for foodstuffs. OJ L 276, 6.10.1990, p. 40. eu (1993), Council Regulation (EEC) No 315/93 of 8 February 1993 laying down Community procedures for contaminants in food. OJ L 37, 13.2.1993, p. 1. eu (1995), European Parliament and Council Directive No 95/2/EC of 20 February 1995 on food additives other than colours and sweeteners, OJ L 61, 18.3.1995, p. 1. eu (1998), Directive 98/6/EC of the European Parliament and of the Council of 16 February 1998 on consumer protection in the indication of the prices of products offered to consumers. OJ L 80, 18.3.1998, p. 27. eu (2000a), Directive 2000/13/EC of the European Parliament and of the Council of 20 March 2000 on the approximation of the laws of the Member States relating to the labelling, presentation and advertising of foodstuffs. OJ L 109, 6.5.2000, p. 29. eu (2000b), Regulation (EC) No 1760/2000 of the European Parliament and of the Council of 17 July 2000 establishing a system for the identification and registration of bovine animals and regarding the labelling of beef and beef products and repealing Council Regulation (EC) No 820/97. OJ L 204, 11.8.2000, p. 1. eu (2000c), Commission Directive 2001/101/EC of 26 November 2001 amending Directive 2000/13/EC of the European Parliament and of the Council on the approximation of the laws of the Member States relating to the labelling, presentation and advertising of foodstuffs. OJ L 310, 28.11.2001, p. 19. eu (2002), Regulation (EC) No 178/2002 of the European Parliament and of the Council of 28 January 2002 laying down the general principles and requirements of food law, establishing the European Food Safety Authority and laying down procedures in matters of food safety. OJ L 31, 1.2.2002, p. 1. eu (2003a), Regulation (EC) No 1829/2003 of the European Parliament and of the Council of 22 September 2003 on genetically modified food and feed. OJ L 268, 18.10.2003, p. 1. eu (2003b), Regulation (EC) No 1830/2003 of the European Parliament and of the Council of 22 September 2003 concerning the traceability and labelling of genetically modified organisms and the traceability of food and feed products produced from genetically modified organisms and amending Directive 2001/18/EC. OJ L 268, 18.10.2003, p. 24.

© Woodhead Publishing Limited, 2011

Regulation of processed meat labels in the European Union

155

eu (2003c), Directive 2003/89/EC of the European Parliament and of the Council of 10 November 2003 amending Directive 2000/13/EC as regards indication of the ingredients present in foodstuffs. OJ L 308, 25.11.2003, p. 15. eu (2004), Regulation (EC) No 853/2004 of the European Parliament and of the Council of 29 April 2004 laying down specific hygiene rules for food of animal origin Council Directive 90/496/EEC of 24 September 1990 on nutrition labelling for foodstuffs (as corrected). OJ L 139, 25.6.2004, p. 22. eu (2006a), Council Regulation (EC) No 509/2006 of 20 March 2006 on agricultural products and foodstuffs as traditional specialities guaranteed. OJ L 93, 31.3.2006, p. 1. eu (2006b), Council Regulation (EC) No 510/2006 of 20 March 2006 on the protection of geographical indications and designations of origin for agricultural products and foodstuffs. OJ L 93, 31.3.2006, p. 12. eu (2006c), Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. OJ L 364, 20.12.2006, p. 5. eu (2006d), Regulation (EC) No 1924/2006 of the European Parliament and of the Council of 20 December 2006 on nutrition and health claims made on foods. OJ L 404, 30.12.2006, p. 9. eu (2006e), Directive 2006/52/EC of the European Parliament and of the Council of 5 July 2006 amending Directive 95/2/EC on food additives other than colours and sweeteners and Directive 94/35/EC on sweeteners for use in foodstuff. OJ L 204, 26.7.2006, p. 10. eu (2007a), Council Regulation (EC) No 700/2007 of 11 June 2007 on the marketing of the meat of bovine animals aged 12 months or less. OJ L 161, 22.6.2007, p. 1. eu (2007b), Council Regulation (EC) No 834/2007 of 28 June 2007 on organic production and labelling of organic products and repealing Regulation (EEC) No 2092/91. OJ L 189, 20.7.2007, p. 1. eu (2008a), Commission Directive 2008/5/EC of 30 January 2008 concerning the compulsory indication on the labelling of certain foodstuffs of particulars other than those provided for in Directive 2000/13/EC of the European Parliament and of the Council. OJ L 27, 31.1.2008, p. 12. eu (2008b), Commission Regulation (EC) No 543/2008 of 16 June 2008 laying down detailed rules for the application of Council Regulation (EC) No 1234/2007 as regards the marketing standards for poultrymeat. OJ L 157, 17.6.2008, p. 46. eu (2008c), Regulation (EC) No 1333/2008 of the European Parliament and of the Council of 16 December 2008 on food additives. OJ L 354, 31.12.2008, p. 16. eu (2008d), Proposal for a Regulation of the European Parliament and of the Council on the provision of food information to consumers (COM(2008) 40 final). fsa (2007), Survey on the meat content of certain meat products, http://www.food. gov.uk/science/surveillance/fsisbranch2007/fsis0607 stubbs, g and more, a (1919), The Analyst, 44, 125. van der meulen, b and van der velde, m (2008), European Food Law Handbook, Wageningen (NL), Wageningen Academic Publishers. woodhead (2010), Catalogue of volumes relating to food science (meat, fish and eggs), http://www.woodheadpublishing.com/en/catalogue.aspx?catalogue= Food%20Science&heading=Meat,%20fish%20and%20eggs

© Woodhead Publishing Limited, 2011

7 Use of sensory science as a practical commercial tool in the development of consumer-led processed meat products M. G. O’Sullivan and J. P. Kerry, University College Cork, Ireland and D. V. Byrne, University of Copenhagen, Denmark

Abstract: This chapter explores the use of sensory science as a practical commercial tool in the development of consumer-led processed meat products. Consequently, the evolution of sensory-based methodologies and approaches used for processed meat product development (including in/out or pass/fail procedure; ratings for degree of difference from a standard; weighting of differences from control; descriptive analysis and flash profiling) is discussed, as well as the use of sensory-based instrumental methods. We also discuss the future opportunities for consumer sensory-based quality control, with an emphasis on the comprehensive holistic approach. This includes the integration of sensory and consumer methods across the processed meat production chain of development, which utilise advanced multivariate data analytical methodologies. Finally case studies are presented which describe how holistic sensory and consumer methods have been used for commercial product optimisation and development. Key words: consumer-led, commercial, processed meats, quality control.

7.1 Introduction To realise the importance of sensory and consumer evaluation in quality control (QC), one must ask the following question: what exactly are consumers buying when purchasing the products we manufacture? They may be buying nutrition, convenience and image, but, most importantly, they are buying sensory properties, sensory performance and product consistency. Therefore, it is clear that sensory techniques must be an integral part in defining and controlling product quality. Every company committed to quality should research, support, develop and operate sensory and consumer-based QC programmes (Muñoz, 2002). However, sensory qualitybased programmes can be costly to start and maintain and some methods

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

157

can be limited in their scope, but it must be remembered that the most important feature of product quality in the marketplace is its direct relationship to consumer perception, satisfaction with and ultimate acceptance of a product’s sensory attributes. Many new products fail because product production and development do not focus systematically on consumer preferences and perceptions of sensory properties. It is clear there is a requirement for strategies and methodologies that allow the food industry to introduce consumer expectations and demands throughout the product cycle in relation to quality control (Pecore and Kellen, 2002; Weller and Stanton, 2002). Additionally, those who work on meat products have to be involved in consumer studies to collect and understand consumer responses to the food products and variables or factors that are being studied (Cross and Stanfield, 1976).

7.2

Past and present status of sensory-based quality control in processed meats

7.2.1 Historically There have been a number of stages in the history and growth of sensory evaluation in quality control of processed meats. Since the first developments of sensory profiling methods in the 1950s, sensory scientists from academia and the food and flavour industries have developed variations of the original techniques. The earliest sensory-based QC methods originate back to the development of sensory evaluation methods and were established by industry (Muñoz et al., 1992a; Muñoz, 2002). Basic sensory methods were developed and the sensory involvement in quality control was in the form of ‘experts’ (1930–1950) (Muñoz, 2002), such as perfumers, brewmasters or winemakers (Muñoz et al., 1992a). This tradition is tied to the use of the senses for detection of well-known defects or expected problem areas. This approach was well suited to standard commodities where minimum levels of quality could be ensured, but excellence was rarely an issue (Lawless and Heymann, 1998a). The processes in turn evolved into more formal QC programmes in the food industry and used trained panels as part of the sensory element in these programmes (1950–early 1960s) (Muñoz, 2002). The US Army Quarter-master Food and Container Institute made many great contributions to early sensory evaluation research. The most well-known contribution was the ‘invention’ of the 9-point hedonic scale (Peryam and Pilgrim, 1957). Cross et al. (1978) developed the most commonly utilised method for descriptive analysis in the testing of meat products. This is the most referenced method for descriptive testing in muscle foods. Additionally the sensory evaluation of processed meat products, has in the past, utilised a modified Meat Descriptive Attribute Method, developed by meat scientists to evaluate the palatability of these products (Nollet, 2007).

© Woodhead Publishing Limited, 2011

158

Processed meats

The next stage of development involved the establishment of QC programmes in the food industry that included a more integrated sensory component and an awareness of the importance of such programmes (early 1960s–1990) (Muñoz, 2002). Chambers et al. (1981) evaluated the performance of ‘semi-trained’ and ‘trained/experienced’ panellists in evaluating the flavour and texture of frankfurters and suggested that highly trained individuals were required to evaluate such foods with complex flavours. The dissemination and utilisation of these techniques by industry was assisted by the publication of QC sensory methods and techniques (Lawless and Heymann, 1998a; Muñoz, 2002). Desmond et al. (1998) assessed tapioca starch, carrageenan, oat fibre, pectin, whey protein and a commercial mixture of carrageenan and locust bean gum for their ability to mimic fat characteristics in cooked low fat (10%) beefburgers. These authors used a 10 member trained panel and the American Meat Science Association (AMSA, 1983) guidelines and evaluated the beef burgers for a number of textural, flavour and overall quality attributes as described by Jeffery and Lewis (1983). The implementation of sensory and consumer methods in a holistic manner in the food industry, particularly the meat industry, has not been attempted and publications of the latest sensory methods and how they can be utilised in product quality control have been virtually non-existent since the early 1990s. Overall, the effectiveness of a QC programme depends, to a large extent, on the type of measurement techniques being used, their validity, reliability and reproducibility. New research is required to establish, modify, introduce and maintain the most appropriate measurement techniques. The most critical of these methodologies are those of sensory and consumer assessment.

7.2.2 Sensory analysis, the consumer and processed meats Sensory methods have some very clear advantages over traditional instrumental QC methods when used in a QC programme. These include the measurement of raw ingredients/materials and finished products as well as ‘in-process’ control. These are the only methods that give a direct characterisation of perceived attributes, measure the interaction in perceived effects and provide information that assists in better understanding of consumer responses (Muñoz et al., 1992a; Costell, 2002; Muñoz, 2002; Pecore and Kellen, 2002). As sensory and consumer measurements determine unique and critical information for the QC cycle, any so-called ‘disadvantages’ such as time and additional costs are negated and accepted, in order to obtain a complete and direct, relevant, end-user view of a product’s quality inadequacies. Basically, without sensory assessment, relevant consumer QC can never be achieved. Consumer testing of meat products is generally performed with

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

159

affective tests of acceptance or preference that are utilised for all food products (Schilling, 2007). In order for any given food product to be commercially successful, consumer desires and demands must be addressed and met with respect to the sensory properties of such products, before other quality dimensions become relevant (Chambers and Bowers, 1993). Consistent product quality is a key focus in the food industry. Ensuring superior quality, however it is defined, is clearly required in the production and distribution of food products. Additionally, product quality directly relates to customer satisfaction and ultimately to repeat sales (Pecore and Kellen, 2002). Each food product category presents its own unique challenges in this regard and processed meat products are no different. The three sensory properties by which consumers most readily judge meat quality are: appearance, texture and flavour (Liu et al., 1995). Once meat is purchased, then sensory evaluation with respect to flavour becomes a more dominant quality for the consumer. Carpenter et al. (2001) surveyed consumers’ preferences for beef colour and found that the type of packaging used would likely sway their decision to purchase. However, the preferences for beef colour and packaging did not bias taste scores. They concluded that the initial perceptions of quality did not likely bias eating satisfaction once a decision to purchase was made and the meat was taken home, thereby hastening the acceptance of the newer packaging technologies. Other examples of consumer studies undertaken on processed meat products have been undertaken to date. Aaslyng et al. (2007), in a study designed to determine the impact of the sensory quality of pork on consumer preferences in Denmark, found that consumers preferred tender, juicy meat with a fried flavour and no off-flavours. Guillevic et al. (2009) conducted a consumer (n = 60) test on chitterling sausages and smoked belly manufactured from pigs fed either a control or linseed oil containing diet. Consumers were instructed to rank visual appearance, overall liking and intent to consume the product again. Results were not significantly different between the treatment groups assessed. Del Nobile et al. (2009) used 80 consumers to assess Italian salami, manufactured from either pork back fat or extra virgin olive oil, for colour, odour and taste. They concluded that salami made from 100% olive oil was unacceptable to consumers, but product containing 60% olive oil soaked whey protein were comparable to commercial product. Pham et al. (2008) assessed eight dry-cured hams with a panel of 71 consumers for the attributes’ overall acceptability, acceptability of flavour, aroma, texture and appearance. These authors presented data that revealed how relationships between sensory descriptors, consumer acceptability and volatile flavour compounds could be determined using external preference mapping and used to comprehend the nature of dry-cured ham flavour as perceived by a consumer panel.

© Woodhead Publishing Limited, 2011

160

Processed meats

7.2.3 Sensory QC programmes for processed meats Most meat and processed meat companies have well-defined and established quality assurance (QA) and QC programmes. The emphasis is mainly on instrumental and chemical analyses. Many, but certainly not all, organisations have QC/sensory programmes, but only a few have sound, wellconstructed and well-defined QC/sensory programmes (Muñoz, 2002). The sensory field has not matched the growth of the technology-driven QC field compared with other disciplines supporting this function (Muñoz, 2002). One of the reasons for this is the cost of maintaining such programmes. Manufacturing executives, unfamiliar with sensory testing, can easily underestimate the complexity of sensory tests, the need for technician time to set up, the costs of panel start-up, panellist screening and training of technicians and panel leaders (Lawless and Heymann, 1998a). Sensory quality is often difficult to define because it is linked not only to food properties or characteristics but to the result of an interaction between the food and the consumer (Costell, 2002). Objective methods allow the comparison of different treatments, as well as ascertaining their effect on a particular characteristic, but do not provide information concerning product acceptability or preference for one kind of meat over another (Wheeler et al., 1997). Therefore, consumer opinion is a key factor in establishing meat value and justifying purchase decisions. Product quality anchored to consumer preference data provides the most objective specification for defining food quality. Ultimately meat products are consumed and it is important that they are assessed by human responses and that reproducible and reliable methods are available to accurately quantify them. Human sensory panels provide the most sensitive measure of quality, detecting trace-to-ultra-trace concentrations of compounds. Panellists can incorporate quantitative information with qualitative nuances of the whole product (Desrochers et al., 2002). Owing to ongoing development, resulting in the increased complexity of foods, including processed meat products, education on appropriate utilisation of sensory analysis must be continued. It is clear that most companies are utilising sensory analysis, but quite often, the wrong methods are being utilised for the stated objectives of the studies (Stone and Sidel, 1993). To date, very little has been published regarding sensory quality control programmes utilised for processed meats. Often, a sensory characteristic flags a quality control problem in a product (Desrochers et al., 2002). An example of this in a processed meat context has been demonstrated by research conducted by Stapelfeldt et al. (1992). These authors used ‘warmedover flavour (WOF) and smell’ to describe an off-flavour associated with cooked meats, which develops as they age. WOF is described as an objectionable flavour which becomes most noticeable when refrigerated cooked meat is reheated. The storage of precooked meat for a short period results in the development of a characteristic ‘old, stale, rancid and painty’ flavour and odour, apparently caused by the catalytic oxidation of unsaturated fatty

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

161

acids (St. Angelo & Bailey, 1987). This off-flavour phenomenon is of particular importance for cooked processed meat products. Tims and Watts, (1958) were among the first workers to recognise warmed-over flavour as a sensory challenge to meat products. In the last few decades there has been a rapid development of fast food facilities and widespread use of precooked frozen meals (Dethmers and Rock, 1975). O’Sullivan et al. (2003a) determined the sensory effects of iron supplementation on WOF development in pork meat patties made from m. longissimus dorsi and m. psoas major, respectively. These authors concluded that m. psoas major was more susceptible to warmed-over flavour development as determined by sensory profiling than m. longissimus dorsi for all experimental treatments. Additionally, Byrne et al. (2002a) suggested that WOF development is the perceived loss in the ‘meatiness’ of samples and the increase in the more oxidative sensory notes during days of storage. Drumm and Spanier (1991) and St. Angelo et al. (1990) have suggested that reactions involving protein degradation and/or heteroatomic compounds leading to a reduction in meatiness may, in addition to lipid oxidation, form an inherent part of WOF development. More specifically, the degradation of unstable sulphur-containing amino acids (in meat proteins) and sulphurcontaining meaty aroma compounds may also be important (Byrne et al., 2002a).

7.2.4 Sensory-instrumental methods As previously described, the emphasis to date on QC programmes has mainly focused on instrumental and chemical analyses with some QC/ sensory programmes. An important field in sensory and consumer science is the study of sensory-instrumental relationships. The idea behind such studies is that sensory perceptions have chemical and physical counterparts in the substance under investigation (Dijksterhuis, 1995). A considerable amount of research has been undertaken to investigate the suitability of advanced sensor technology to simulate human sensory responses. The development of valid and relevant instrumental methods in concert with dynamic sensory methods has allowed for a more comprehensive analysis of human perception (Ross, 2009). This can be achieved by direct correlation of panellist or consumer responses to instrumental measurements using multivariate data analysis, which also plays an important part in sensory-based QC programmes. Up to the present, the analysis of characteristic food odours has been commonly carried out by human assessment and headspace/direct gas chromatography mass spectrometry (GC/MS) (Grigioni et al., 2000). The usefulness of GC/MS is obvious for the detection of WOF in cooked chill stored meat products, but as a technique, it has certain drawbacks. Instrumental techniques, like GC/MS, have high operating costs and are time consuming (Pryzbylski and Eskin, 1995). However, the electronic nose (E-nose) may

© Woodhead Publishing Limited, 2011

162

Processed meats

provide a practical advantage over other methods and may have an application in an on-line/at-line capacity for the quality determination of meat products with respect to WOF development (O’Sullivan et al., 2003c). If an E-nose is to be used in QA and QC programmes for raw materials and/or end products, there is a need to calibrate it against sensory assessment in order to determine the relevance of the measurements (Hansen et al., 2005). However, the E-nose has large differences in both sensitivity and selectivity from the human nose (Haugen and Kvaal, 1998). To date, E-nose technology has been employed in the analysis of a large variety of meat products (e.g. Eklöv et al., 1998, fermented sausage; Ólafsdóttir et al., 1997, fish; Hansen et al., 2005, meatloaf; Tikk et al. 2008, meatballs) and in the warmedover flavour analysis of various meat products (e.g. Siegmund and Pfannhauser, 1999, chicken; Grigioni et al., 2000, beef; O’Sullivan et al., 2003c, pork). O’Sullivan et al. (2003c) found that the E-nose device used in a WOF experiment for cooked pork could clearly separate samples on the basis of muscle type, treatment and degree of WOF development. Additionally, the E-nose data from two separate sample sets analysed in different laboratories and with a time separation of 11 months concurred with sensory analysis and the device used in this experiment was effective in determining the oxidative state of the samples analysed. This displayed the potential effectiveness of the E-nose as an objective on-line/at-line QC monitoring device. Additionally, Tikk et al. (2008) concluded that a significant, positive correlation between the E-nose gas sensor signals, the WOF-associated sensory attributes and the levels of secondary lipid oxidation products for pork meat balls, a very popular Danish dish. This also supports the potential of E-nose technology as a potential future QC tool in the meat industry. Hansen et al. (2005) demonstrated that an E-nose could predict the sensory quality of porcine meat loaf, based on measuring the volatiles in either the raw materials or the meat loaf produced from those raw materials. They further stipulated that a strategy involving an operational and standardised methodology and vocabulary for in-house sensory evaluation of the raw materials was essential if the electronic nose was to be calibrated properly and used on-line in the future.

7.3 State of the art: an overview of specific sensory science methodologies and approaches used for processed meat product development 7.3.1 QC methodologies In general, sensory-based QC protocols can be separated into two distinct categories: difference tests and descriptive tests. Of the four methods of sensory QC (Muñoz et al., 1992a,b; Lawless and Heymann, 1998a,b), the first three can be considered difference tests and include the methods; ‘In/Out’,

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

163

In/Out method Score the sample provided. Record comments Symbol

Score

Comments

------------------------------------------------------------------------------------------------------------------------------------------------------------

Test sample

Scoring scale 10 = Perfect

9 = Very good

8 = Good

7 = Borderline

6 = Reject

Degree of Difference from a Standard Score the sample provided. Record comments

Symbol

Score

Odd sample

Comments

------------------------------------------------------------------------------------------------------------------------------------------------------------

Standard sample

Scoring scale

10 = Perfect

Fig. 7.1

9 = Very good

8 = Good

7 = Borderline

6 = Reject

Example of scoring sheets for a processed meat product.

‘Ratings for degree of difference from a standard’ and ‘Weighting of differences from control’. These difference tests are described briefly below and are used ubiquitously across the food industry. Figure 7.1 provides examples of scoring sheets. However, the fourth method is descriptive and will be explored in detail with respect to processed meat products. In the ‘In/Out’ method, daily production is evaluated by a trained panel as being either within or outside sensory specifications (Muñoz et al., 1992b).

© Woodhead Publishing Limited, 2011

164

Processed meats

The ‘Ratings for degree of difference from a standard’ method is used in order to determine how much any production sample varies or deviates from a standard (Muñoz et al., 1992c). The third difference test that can be used is ‘Weighting of differences from control (individual experts)’ and is similar to the degree of difference from a standard method. Difference tests carry a number of disadvantages compared with descriptive testing, for example, the ‘In/Out’ method does not provide descriptive information that can be used to amend problems (Muñoz et al., 1992b). The ‘Ratings for degree of difference from a standard’ method does not provide any information regarding the source of differences compared with a control (Muñoz et al., 1992b). Finally, the ‘Weighting of differences from control’ entails an even more complex judgement procedure on the part of panellists, since it is not only the differences that matter, but also how they are weighted in determining product quality (Lawless and Heymann, 1998a).

7.3.2 Descriptive analysis Descriptive analysis has been used to quantify the sensory attributes of processed meat products within the industry. The method has a number of advantages over difference testing in that it is quantitative and can be used to describe differences between products and the main sensory drivers (be they positive or negative, identified within products or especially when combined with objective consumer testing and objective multivariate data analysis). However, the method can be expensive and time consuming because of the necessity to train and profile individual panellists over extended periods of time; days or even weeks. It is also not a method that can be readily used for routine analysis. Later we will discuss ‘flash profiling’ (FP) as a compromise method of analysis. Descriptive analysis is a method where defined sensory terms are quantified by sensory panellists. A list of descriptive terms are determined initially and are referred to as a lexicon or descriptive vocabulary and describe the specific sensory attributes in a meat sample and can be used to evaluate the changes in these attributes (Byrne and Bredie, 2002). There are two methods of descriptive analysis, the Spectrum and the QDA (quantitative descriptive analysis) methods. The Spectrum method’s principal characteristic is that the panellist scores the perceived sensory intensities with reference to prelearned ‘absolute’ intensity scales. This essentially makes the resulting profiles universally understandable. The method provides for this purpose an array of standard attribute names (‘lexicons’), each with its own set of standards that define a scale of intensity (Muñoz and Civille, 1992; Meilgaard et al., 1999). The Spectrum method employs the use of a strictly defined technical vocabulary using reference materials. These descriptive terms can be initially determined from lexicons of descriptive terms, which have been developed and employed by a number of authors for the sensory

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

165

evaluation of meat products; Johnson and Civille (1986) for beef, Lyon (1987) and Byrne et al. (1999b) for chicken; Byrne et al. (1999a), Byrne et al. (2001a,b) and O’Sullivan et al. (2002) for pork. Sensory factors in meat include; tenderness, juiciness, flavour, aroma and colour (Cross, 1987). Cross et al. (1978) originated the most commonly utilised method for descriptive analysis in the testing of meat products. The QDA method first proposed by Stone et al. (1974) relies heavily on statistical analysis to determine the appropriate terms, procedures and panellists to be used for the analysis of a specific product. The training and QDA panel requires the use of product references to stimulate the generation of terminology. The panel leader acts as facilitator, but does not influence the group. Panellists do not discuss data, terminology or samples after each taste session, but must depend on the discretion of the panel leader for any information on their performance. Feedback is provided by the facilitator based on the statistical analysis of the taste session data (Lawless and Heymann, 1998b; Meilgaard et al., 1999; Miller, 1994). For the QDA method, along with such lexicons, experts with product knowledge can evaluate a sample set of the meat to be profiled in the laboratory and suggest descriptive terms that specifically describe the meat product to be tested and the sensory dimension to be examined, e.g. WOF in cooked pork (O’Sullivan et al., 2002). Once an initial list of terms is decided upon, the next step is to reduce these terms through the training and term reduction process. In order for a term to be included during subsequent profiling it must fit the following criteria: the sensory terms selected must (1) be relevant to the samples, (2) be capable of discriminating between samples, (3) have cognitive clarity and (4) be non-redundant (Byrne et al., 1999a,b, 2001b; O’Sullivan et al., 2002, 2003a). Various means can be employed in this term reduction process and these have included principal component analysis (PCA) in conjunction with assessor suggestions (Byrne et al., 1999a,b, 2001b; O’Sullivan et al., 2003a). Free choice profiling (FCP) can also be used and this involves panellists developing their own descriptive terms (Delahunty et al., 1997). For example the quality of ham is judged by various sensory characteristics. Untrained ham consumers easily discriminate between hams in terms of appearance, texture, flavour and overall preference using FCP (Válková et al., 2007). The disadvantage of this method is the subjective correlation of terms derived by different assessors may not, in reality, be related. Detailed descriptions of sensory terminology and procedural guidelines for the identification and selection of descriptors for establishing a sensory profile by a multidimensional approach have been described in ISO (1992) and ISO (1994), respectively. Descriptive profiling has been described in detail for cooked meat products by a number of authors (Byrne et al., 1999a, 2001a; O’Sullivan et al., 2002, 2003a,c, for pork; Byrne et al., 1999b, 2002a, for chicken; Mielche and Bertelsen, 1993, for Beef).

© Woodhead Publishing Limited, 2011

166

Processed meats

7.3.3 Flash profiling Recently, Sieffermann (2000) suggested combining FCP with a comparative evaluation of the product set in a technique named flash profiling. This may offer a compromise over conventional descriptive methods. Flash profiling is a sensory descriptive method derived from FCP where each subject chooses and uses his/her own words to evaluate the whole product set comparatively (Dairou and Sieffermann, 2002). Flash profiling is a quick sensory profiling technique designed to meet industrial needs. It is based on the combination of free choice profiling and a comparative evaluation of the whole product set (Delarue and Sieffermann, 2004). Comparisons between flash profiling and conventional profiling results have already been published (Loescher et al., 2001; Dairou and Sieffermann 2002, Delarue and Sieffermann, 2004). Delarue and Sieffermann (2004) comparing flash profiling with conventional profiling using the products strawberry blended yoghurts and apricot ‘fromages frais’, both from the French market. These authors found that for both product sets, flash profiling was slightly more discriminating than the conventional profile. The flash profiling method appeared to be less time-consuming than the conventional profile and thus seems to be an interesting alternative method to evaluate quickly an array of products (Dairou and Sieffermann, 2002). Additionally, Rason et al. (2003) conducted flash profiling on French dry sausages. In this study test subjects generated their own list of sensory terms for appearance, texture, aroma and flavour for 12 traditional French dry sausages. These lists were then used by individual panellists to evaluate the test products simultaneously. This technique enabled a quick positioning of the traditional dry sausages on a sensory map (Sieffermann, 2000). Flash profiling is a quick substitute method but also provides an initial comprehension of the most important attributes of a product’s set (Dairou and Sieffermann, 2002). It is less time consuming than traditional profiling because training is not required. All samples are prepared before the sessions and presented to the assessors at the same time and subjects choose their vocabulary according to his/her own sensitivity and perception (Dairou and Sieffermann, 2002). This new method of sensory profiling may have useful applications in the sensory evaluation of processed meat products. This is even more relevant considering the convenient methodology employed compared with the more conservative methods and the necessity to minimise costs within the very competitive processed meat sector.

7.4

Future trends: a holistic implementation of sensory science at key stages of meat product development

Up to this point we have given an overview of the development and present state of the art in sensory-based quality control systems methodology.

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

167

Muñoz and Chambers (1993) reported that relating consumer data to laboratory data (instrumental and or trained panellists) addresses the limitations of consumer panels. However, in the future it is envisaged that sensory methods can be implemented across the production chain in strategic applications to introduce the consumer and sensory elements into the production and development of processed meat products. The objective is to develop and manufacture products for those that will ultimately consume them, through the integration of the end user (Grunert et al., 2008). This can be achieved in a cost-effective manner, either via flash profiling based on initial sensory investigations or via instrumental measurements which have been calibrated by sensory measurements (O’Sullivan et al., 2003a,b,c) and proven to represent the sensory tolerances of the consumers (Hansen et al., 2005). We view the future of sensory science as developing in this way, the basis of this development began in the 1990s with Muñoz et al. (1992a) and more recently by Nissen and Byrne (2005) and Byrne and O’Sullivan (2011a,b). Munoz has indicated that QA and QC programmes are established within an organisation to pursue and maintain the products’ quality. QA represents those planned or systematic actions necessary to provide adequate confidence that a product or a service will satisfy given needs (Muñoz, 2002). The idea for a sensory-based quality system was first presented in the mid-1990s. Gillette and Beckley (Beckley and Kroll, 1996) developed a sensory quality system (SQS) for industry to provide assurance of product quality across multiple plants and multiple companies. The programme aided in the prevention of flavour drift over time and also assisted in the flow of information between plants to match target product. (King et al., 2002). Ultimately the method was widely adopted by production and quality laboratories across the production chain from raw ingredient to finished product monitoring. Most recently there have been developments in the area of holistic and strategic applications of sensory and consumer science in QC in the processed meat industry. Byrne and coworkers (Byrne 2006, 2007; Nissen and Byrne, 2005; Byrne and O’Sullivan, 2011a,b) have developed a holistic sensory-based QC approach termed the ConSense approach. The purpose of this was to develop and define a strategic, data analysis-based, QC indexing methodology for the food industry (Byrne, 2006). This approach was developed through unique multivariate data analytical application and investigation of measurements from key stages of the production chain, and their causal and predictive relationships to the sensory properties of processed, competitive, high quality food products (Martens and Martens, 2001; Byrne and O’Sullivan, 2011a,b). The developed strategy allows for acquisition of information on how the qualities that already exist in the raw material can be transferred, utilised and preserved in processed products such that they are consistently high and of superior quality from a sensory

© Woodhead Publishing Limited, 2011

168

Processed meats

Phase 1: Normal production, inherent variation

ConSense

Phase 2: Normal production, designed variation

Phase 3: Outside normal production, designed variation (development context)

Fig. 7.2 Schematic of the ConSense, holistic, three phases and their interaction. The strategy was developed in a three-phase stepwise manner: Phase 1: Identify specific products with quality variation and develop strategy aspects. Phase 2: Implement changes on existing products and test effectiveness of the approach in improving quality from a sensory and marketplace consumer perspective. Phase 3: Implement strategy in a ‘new’ product development context (NPA) and document the approach and its holistic nature.

perspective. The ConSense strategy innovatively integrates the end user, in that, when products are developed, produced and manipulated, the effects on consumer acceptability and perception are used as key criteria in the implementation of changes in the production chain, in order to maintain and increase quality (Byrne and O’Sullivan 2011a,b). Overall, the ConSense approach consisted of three interconnected and progressive stages of development (Fig. 7.2). The initial aim was to understand the large inherent variation in normal production. The second phase was aimed at reducing and controlling inherent variation by making targeted changes to production parameters within least cost formulation (LCF) constraints. The third and final stage involved the implementation of the strategy in a product development situation, with the implementation of changes outside LCF constraints. The unique characteristic of each phase is that all were developed and carried out on industrial-scale production, such that the results are directly applicable and do not suffer from extrapolation and up-scaling error (Byrne, 2006, 2007; Byrne and O’Sullivan, 2011a,b) The work of Byrne and O’Sullivan (2011a,b) displayed high levels of significant causality and predictivity across the production chain with respect to identified factors and their influence on sensory and consumer preference

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

169

in Phase 1. Moreover, changes based on inherent/normal variation in Phase 1 implemented within LCF guidelines in Phase 2 were determined to have significant impacts on improving sensory and consumer acceptability. Focused changes implemented in a ‘product development’ capacity outside LCF in Phase 3, based on inherent/normal variation and changes within LCF variation, were determined to have an even greater significant influence in enhancing sensory and consumer responses. Once inherent variation was modelled, then the systematic targeted changes within and outside LCF were determined to reduce product quality and variability significantly, because as one moved more in the direction of designing the product’s sensory characteristics for the end user, the greater the level of relevance for the consumer the product attained. Overall, the ConSense strategy was determined to be extremely effective from an application perspective and shed much light on the factors influencing sensory quality of the product from a consumer perspective (Byrne and O’Sullivan, 2011a,b). Overall, the main issues in terms of effects on sensory and consumer perception of product variation were found primarily with specific raw materials followed by processing parameters. Following from this the information gleaned in experimentation with standard production and that from intervention in LCF was utilised to make changes to production, in what could be called a ‘product development capacity’ (Phase 3), as the aim was to move outside of (LCF), however, remaining within legal constraints (Fig. 7.3). The response was a quantifiable significant improvement in sensory consumer reaction to the changes implemented in production and raw materials with a significantly reduced level of variability in production variation at the same price per unit cost (Byrne and O’Sullivan, 2011a,b). Data from three sensory profiles from normal production, inside LCF and outside LCF, Phases 1, 2 and 3, respectively, was linked via multivariate data analysis (MVA) to consumer analysis with 200 consumers. For Phases 2 and 3 the overall-liking for the product was measured (Fig. 7.3). It was clear that the consumers preferred the designed products, in particular in the case of products where changes were made outside LCF (Byrne and O’Sullivan, 2011a,b). A number of key areas across the production chain were highlighted as important with respect to control to ensure enhanced consistency in product quality. From a scientific perspective it was conclusively demonstrated that the stepwise approach forming the basis of the presented data was systematically effective in its aims to influence consumer perception of product quality via reduction in quality variation and enhancement in production quality (Fig. 7.4). In terms of the methodological aspects of the present project it was demonstrated that a systematic use of multivariate data analytical techniques in the holistic linking of key data generated across the production chain was highly effective in production variation and quality improvement (Fig. 7.4).

© Woodhead Publishing Limited, 2011

170

Processed meats

Phase 3

Principal component 2 (Y-explained variance 17%)

1.0

Designed outside LCF S2 Outside LCF

Overall preference

0.5

S1 Outside LCF Skatole-O

Fresh Pork-F

Hardness-Tx

Salt-T Crumbliness-Tx Sickly-O

S2 Normal

Smoked-F Fresh Pork-O Stable-O

Smoked-AT

Lactic-F

0.0

Smoked-O Fatty-AT

S2 Inside LCF

Sticky-Tx

Astringent-AT

S1 Normal

–0.5

Chewiness-Tx

Spicy-O

Pepper-AT

Paprika-F

Coriander-F

Sweet-T

Umami-T

Phase 1

Brown-C

S1 Inside LCF

Pepper-F

Sour-O

Normal Production

Phase 2 Designed inside LCF

–1.0 –1.0

–0.5

0.0

0.5

1.0

Principal component 1 (Y-explained variance 34%)

Fig. 7.3 External preference mapping of samples from each the three phases of ConSense development plus expert sensory description (X-matrix) in relation to liking of consumers (n = 205) of the samples from each phase (Y-matrix). Presentation of the effect of changes to sample liking from normal production within LCF to outside LCF effects. The cluster of points indicates the direction of consumers’ preferences for the products in the direction of Phases 2 and 3 and in particular correlated to designed variation outside LCF (adapted from data from Byrne and O’Sullivan (2011a,b). The inner and outer ellipses represent r2 = 50% and 100%, respectively. AT = aftertaste, Tx = texture, O = odour, F = flavour, C = colour, skatole = feacal, farmyard off note.

Overall, Byrne and O’Sullivan (2011a,b) concluded that from a practical perspective a number of aspects of ConSense could potentially be implemented as part of established QA programmes. A generic protocol can now be generated where a systematic set of guidelines and methodological areas can be presented in summary with potential applicability to the food industry, including processed meat production (Byrne, 2006, 2007). It is clear that many QC situations are unique, and vary in their complexity across the meat processing industry; however, the basic elements determined as a result of the ConSense approach are generic in their applicability to specific quality assurance scenarios (Byrne and O’Sullivan, 2011a,b). One must think, holistically, use data from the total production chain, ensure sensory and consumer aspects are considered as key elements and are integrated into the QA programme. The utilisation of state-of-the-art

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

Production changes implemented

Raw material data

Processing data

Finished product data

Production changes implemented

171

Consumer assessments

Data analysis

Affective decisions

Sensory assessments

Fig. 7.4 An overview schematic of the overall dynamics of the ConSense strategy. It indicates the movement of information/data forwards from the various stages of production, from raw materials through manufacturing to finished product to its inclusion in holistic data analysis by MVA. Moreover, the integration of sensory and consumer information with production data is displayed. Furthermore the coordinated decision making based on the overall analysis returns to the chain such that the process becomes dynamic and constant in its influence (adapted from Byrne and O’Sullivan, 2011a,b).

multivariate techniques in addressing these data sets is required and once the solutions are uncovered, they must be implemented as part of the ongoing programme of quality improvement in a production scenario. In this respect it is well known that large quantities of process data are collected in relation to process monitoring within food production. However, much of the data is not utilised in an efficient way with respect to aiding product quality enhancement. The ConSense method aims to ensure that the data are utilised more efficiently through identifying the most important critical control points in industrial data collection during processing (Byrne and O’Sullivan, 2011a,b). The implications of a ConSense type strategy for the food industry are that a reasonable level of investment is possible in the initial phases and considered cost effective. A sensory and consumer holistic multivariatebased QC/QA programme should be put in place, maintained and the targeted findings utilised. If implemented this presents a clear benefit to the company’s revenue within a reasonable space of time (Byrne and O’Sullivan, 2011a,b). Finally, the Internet must not be ignored when considering holistic sensory methods of production quality control. Findlay (2002) asks the question ‘Where is the web going in the future and how does all of this relate to the sensory quality control?’ He postulates that the results of our sensory assessments will be part of the data flow that controls manufacturing processes directly.

© Woodhead Publishing Limited, 2011

172

Processed meats

7.5

Conclusions: success in processed meat product production development – sensory science-based development of successful consumer processed meat products

It is well documented that more than 90% of all new product development (NPD) in the food and beverage industries fails – some claim the figure is in fact closer to 98%. However, the 2% that is successful accounts for billions of pounds, dollars, yen and euros worth of business everyday, which begs the question: is the risk a worthy one? (Business Insights, 2004) It is clear that most companies are using sensory analysis, but quite often, the wrong methods are being utilised for the stated objectives of the studies (Stone and Sidel, 1993). Therefore, the question must be asked, what separates the losers from the winners in NPD? Stewart-Knox and Mitchell (2003) indicated that a low rate of innovation, coupled with the high failure rate of food products following market launch implied that the methodology for new food product development was long overdue for a systematic rethink and clearly needed vast improvement. With appropriate consumerdriven methodologies, processed meat companies could considerably increase the success of new product launches. Consistent product quality is a key focus in the meat and food industry. Ensuring superior quality, however it is defined, is clearly required in the production and distribution of meat products in particular. These are notoriously complex and inconsistent in quality due to raw material variation and the necessity to use LCF born out of volatile commodities markets. This is critical of course as product quality directly relates to customer satisfaction through sensory properties and ultimately to repeat sales. The involvement of the end user is paramount in that, when products are developed, produced and manipulated, the effects on consumer acceptability and perception will be used as key criteria in the implementation of changes in the production chain, in order to maintain and increase quality. However, reducing this lofty goal to practice is the challenge, particularly in a large company with multiple products and multiple manufacturing locations (Pecore and Kellen, 2002). The processed meat industry is now at a mature stage where product development and innovation are necessary to bring about significant demand growth. As a result of these changes, interest in new red meat products, particularly convenience-oriented products, has dramatically increased in recent years (Resurreccion, 2004). Descriptive sensory analysis in combination with effective sensory analysis carried out with potential users of the product can be considered central to promoting success in innovation with respect to the end user. Objective sensory measurements combined with affective sensory analyses are particularly suitable for testing the effectiveness of product improvements/ optimisation and NPD potential. Furthermore, they allow a targeted

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

173

adjustment of sensory properties with the purpose of obtaining a higher degree of consumer satisfaction (Byrne, 2006; Moskowitz et al., 2006; Muñoz, 2002). From a number of key perspectives sensory measurements are clearly integral to user-driven innovation adding much fundamental and applied insight as to why consumers form preferences for certain foods and not others. When it comes to making choices about food, the underlying reasons for our likes and dislikes are not easily accessible to our reasoning (Dijksterhuis and Byrne, 2005), but still, sensory objective descriptive methods rely largely on panellists’ conscious action (Frandsen et al., 2003; Koster, 2003). Overall, this will lead to increased success rates for new products in the marketplace and thus lower the cost of product development and give an extended life for established products through improvement of their sensory properties. Application of the ConSense strategy in the product development context will lead to a consistently higher quality and greater consumer satisfaction in the new products. Ultimately such strategies will ensure that meat products are nutritious and of a high quality, and promote the development of new products characterised by a large degree of innovation. This will strengthen the competitive status of the industry and enable the food industry to meet the new demands of consumers.

7.6 Case studies The ConSense method described above displays how systematic use of multivariate data analytical techniques in the holistic linking of key data generated across the production chain was highly effective in reducing production variation and quality improvement from a consumer sensory perspective. MVA may also be used to assist in identifying the key sensory drivers that affect consumer preference. A case study is presented below displaying how product optimisation can be achieved using MVA and effective consumer analysis. A small food business operator (FBO) and manufacturer of healthy, additive-free, meat-based ready meals approached our research group (Food Packaging Group, UCC) to assist in optimising their product range (five products). Sponsorship for the research undertaken was provided by Enterprise Ireland (the Irish Government agency responsible for the development and promotion of the indigenous business sector). Five steps were involved in the above optimisation process: 1. Identifying all competitor products. This was achieved by conducting an extensive supermarket survey where the product range was sold in the retail sector and recording the different competitor products and certain relevant information such as stocking densities.

© Woodhead Publishing Limited, 2011

174

Processed meats

2. Development of the consumer questionnaire. All products within the FBO’s product range, as well as all the relevant competitor products were sensory evaluated by experts with product knowledge to compile the consumer questionnaire descriptor list. Descriptors included those for appearance, flavour, texture, off-flavour as well as product overall acceptability and packaging quality. 3. Consumer evaluation. A group of 26 consumers (naive assessors), who were consumers of similar convenience-type ready meals and who also fitted the consumer demographic (males and females (50/50) 20–30 years of age), were recruited. These naive assessors were asked to evaluate all products (test products and competitor products) and to indicate their score on a continuous 10 cm line scale ranging from 0 (none) on the left to 10 (extreme) on the right for each sensory or hedonic descriptor. The presentation order for all samples presented over two sessions was randomised to prevent first order and carry-over effects (MacFie et al., 1989). 4. Data mining was then performed using ANOVA partial least squares regression (APLSR) to process the raw data accumulated from the 25 test subjects during the consumer sensory evaluation. From these data, consumer product variation and ranking could be determined for the test product range as well as all competitor products. In effect, the test product’s position in the consumer landscape was determined along with positive and negative sensory drivers identified for each product. 5. Product optimisation. Positive sensory drivers were increased and negative drivers were decreased by reformulation. Reformulated products were then evaluated using the same consumer panel as before. A clear increase in product ranking was observed for each test product. When the optimised products went in to commercial production and subsequent retail sale, over a short period of time the FBO observed increased sales and an increase in market share. Furthermore, some of the products went on to win primary food awards for their food category in internationally recognised food award competitions. The optimisation protocol was thus effective. It must also be noted that chemical (i.e. lipid oxidation or compositional data) or instrumental data (i.e. GC-MS) may also be included with sensory or consumer data in the MVA models. This may provide additional information for identification of sensory drivers for optimisation. This consumer-driven optimisation strategy has been used with success for product development and optimisations for a number of products including meat-based ready to eat meals, soups, savoury pies, conveniencetype seafood products as well as alcoholic beverages. One may question using such a small group of consumers (25 naive assessors, consumers) in making such important commercial decisions. The reality is that small food businesses cannot afford large-scale consumer evaluations using perhaps

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

175

200, 300 or even 1000 consumers. Additionally, larger-scale consumer evaluations take a considerably longer time to organise, conduct and data mine. From start to finish, months can elapse and in such an extended period of time, the consumer marketplace or demographic can change, which questions the accuracy of the information accumulated. Effective, robust consumer-driven innovation strategies can assist companies in getting their products in to the marketplace in a speedy fashion and also ensure the optimised products are not obsolete from a consumer relevance perspective, but are specifically designed to meet consumer requirements. The success of the consumer-driven strategy described above can be measured by the increased profits and market share of the companies that have been engaged with. Additionally, consumer sensory work undertaken recently (Zakrys-Walliwander et al., 2010) has produced similar findings to parallel studies using thousands of consumers which further validates this methodology. Essentially, for Irish consumers, flavour is considered more important with respect to meat acceptability than toughness for beef steak products. In contrast, Dransfield et al. (1984) postulated that tenderness and juiciness were the properties that most influenced meat acceptability. Table 7.1 gives a general overview of the main differences between methods of sensory profiling.

7.7 Acknowledgements 7.7.1 Acknowledgements for contributions by D. V. Byrne The research featured in this chapter was funded by The Danish Ministry of Food, Agriculture and Fisheries under the research programmes ‘The Innovations Law’ (2002–2006) (The ConSense Approach: no. 93s-2466-Å02-01585) and ‘Food technology, safety and quality’ (2003–2006) (Sense-Index. No. FSK03-13). The Department of Food Science, Faculty of Life Science, University of Copenhagen is also greatly acknowledged for its support for the sabbatical period of author Byrne within the Food Packaging Group at University College Cork who hosted his stay and where this chapter was developed. The support of the FoodUnique Network (www.foodunique.eu) funded by the Danish Strategic Research Council is also acknowledged for facilitating completion of this collaborative effort.

7.7.2

Acknowledgements for contributions by M. G. O’Sullivan and J. P. Kerry Sponsorship for the research undertaken in the case study section was provided by Enterprise Ireland (the Irish Government agency responsible for

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

b

a

Active

Passive

?b

Active

4–8

6–8

Passive

Active

Extensive use of Yes references not only from the product under evaluation Products from the Yes/no category under evaluation None No

Yes

2–3 weeks?b

Unstructured 15 cm linea Unstructured 15 cm absolute line; 30-point; magnitude estimation Numerical

13-point

5-point

Some instructions Yes Unstructured 15 cm with the scale?b (GPA) linea

Yes

Yes

No

No

Statistical Scale analysis

50–95 h

10–15 h

130 h over 6–7 months

2–3 weeks?b

Quantitative Training reference

Products from the Yes/no category under evaluation Products from the Yes/no category under evaluation None No

The ‘unstructured 15 cm line-scale’ may often contain anchors. ? = No clear specification was found in the literature.

Profile Panellist attribute based analysis Free choice Idiosyncratic profiling

Spectrum

Panellist based Technical

QDA

10–12

6–9

Panellist based

Texture profiling

Active

No of Panel Qualitative panellists leader’s role reference

4–8

Vocabulary

Flavour Panellist profiling based

Method

Table 7.1 A general overview of the main differences between methods of sensory profiling

Use of sensory science as a practical commercial tool

177

the development and promotion of the indigenous business sector). This funding was part of both the innovation partnership scheme and the innovation voucher scheme. The objective of the Innovation Partnership and Innovation Voucher initiatives is to build links between Ireland’s public knowledge providers and small businesses and create a cultural shift in the small business community’s approach to innovation (www.innovationvouchers.ie). Additional work was funded by the Irish Food Industry Research Measure (FIRM) as part of the project titled ‘Quantification of variation in beef at processor, retailer, consumer level and within certain beef markets to achieve a full palatability assured critical control points (PACCP) system’.

7.8 References and further reading aaslyng, m.d., oksama, m., olsen, e.v., bejerholm, c., baltzer, m., andersen, g. bredie, w.l.p., byrne, d.v. and gabrielsen, g. (2007). The impact of sensory quality of pork on consumer preference. Meat Science, 76, 61–73. amsa (1983). Guidelines for sensory, physical, and chemical measurements in ground beef. Reciprocal Meats Conference Proceedings, 36, 221–228. beckley, j.p. and kroll, d. (1996). Searching for sensory research excellence. Food Technology, 50(2), 61–63. berdagué, j.l., monteil, p., montel, m.c. and talon, r. (1993). Effects of starter cultures on the formation of flavour compounds in dry sausage. Meat Science, 35, 275–287. boles, j.a., mikkelsen, v.l. and swan, j.e. (1998). Effects of chopping time, meat source and storage temperature on the colour of New Zealand type fresh beef sausage. Meat Science, 49, 79–88. business insights (2004). Future Innovations in Food and Drinks to 2006: Forwardfocused NPD and consumer trends. http://www.researchandmarkets.com/ reports/227408/future_innovations_in_food_and_drinks_to_2006. byrne, d.v. (2006). Integration of sensory and consumer drivers in quality control to optimise production and development in the food industry: the Con-Sense Approach. 52nd International Congress of Meat Science and Technology 13–18 August 2006. Posters. 551–552 Conference: International Congress of Meat Science and Technology: Harnessing and Exploiting Global Opportunities, no. 52, Dublin, Ireland. byrne, d.v. (2007). ConSense. Proceedings of the 37th Annual Research Conference on Food, Nutrition and Consumer Sciences, University College Cork, Cork, Ireland. byrne, d.v. and bredie, w.l.p. (2002). Sensory meat quality and warmed-over flavour: a review. In F. Toldrá, Research Advances in the Quality of Meat and Meat Products. Trivandrum: Research Signpost, 95–212. byrne, d.v. and o’sullivan, m.g. (2011a). ConSense: sensory based control strategies in food production and development. New Food, (in press). byrne, d.v. and o’sullivan, m.g. (2011b). Implementation of sensory and consumer based changes in production of frankfurter-type sausages. Journal of the Science of Food and Agriculture, (submitted). byrne, d.v., bak, l.s, bredie, w.l.p, bertelsen, g. and martens, m. (1999a). Development of a sensory vocabulary for warmed-over flavour 1: in porcine meat. Journal of Sensory Studies, 14, 47–65.

© Woodhead Publishing Limited, 2011

178

Processed meats

byrne, d.v., bredie, w.l.p. and martens, m. (1999b). Development of a sensory vocabulary for warmed-over flavour: Part II. In chicken meat. Journal of Sensory Studies, 14, 67–78. byrne, d.v., bredie, w.l.p., bak, l.s., bertelsen, g., martens, h. and martens, m. (2001a). Sensory and chemical analysis of cooked porcine meat patties in relation to warmed-over flavour and pre-slaughter stress. Meat Science, 59, 229–249. byrne, d.v., o’sullivan, m.g., dijksterhuis, g.b., bredie, w.l.p. and martens, m. (2001b). Sensory panel consistency during development of a vocabulary for warmed-over flavour. Food Quality and Preference, 12, 171–187. byrne, d.v., bredie, w.l.p., mottram, d.s. and martens, m. (2002a). Sensory and chemical investigations on the effect of oven cooking on warmed-over flavour development in chicken meat. Meat Science, 61, 127–139. byrne, d.v., o’sullivan, m.g., bredie, w.l.p. and martens, m. (2002b). Descriptive sensory profiling and physical/chemical analyses of warmed-over flavour in meat patties from carriers and non-carriers of the RN− allele. Meat Science, 63, 211–224. carpenter, c.e., cornforth, d.p. and whittier, d. (2001). Consumer preferences for beef color and packaging did not affect eating satisfaction. Meat Science, 57, 359–363. chambers, e. and bowers, j. (1993). Consumer perception of sensory quality in muscle foods: sensory characteristics of meat influence consumer decisions. Food Technology, 47, 116–120. chambers, e., bowers, j.a. and dayton, a.d. (1981). Statistical designs and panel training/experience for sensory analysis. Journal of Food Science, 46, 1902. costell, e. (2002) A comparison of sensory methods in quality control. Food Quality and Preference, 13, 341–353. cross, h.r. (1987). Sensory characteristics of meat. Part 1 ∼ Sensory factors and evaluation. In: J.F. Price, and B.S. Schweigert, editors. The Science of Meat and MeatProducts, 3rd ed. Westport, CT: Food and Nutrition Press, Inc., 307–327. cross, h.r. and stanfield, m.s. (1976). Consumer evaluation of restructured beef steaks. Journal of Food Science, 41(5), 1257–1258. cross, h.r., moen, r. and stanfield, m.s. (1978). Training and testing of judges for sensory analysis of meat quality. Food Technology, 32, 48–52, 54. dairou, v. and sieffermann, j.m. (2002). A comparison of 14 jams characterized by conventional profile and a quick original method, the Flash profile. Journal of Food Science, 67(2), 826–834. delarue, j. and sieffermann, j.m. (2004). Sensory mapping using Flash profile. Comparison with a conventional descriptive method for the evaluation of the flavour of fruit dairy products. Food Quality and Preference, 15, 383–392. delahunty, c.m, mccord, a., o’neill, e.e. and morrissey, p.a. (1997). Sensory characterisation of cooked hams by untrained consumers using free-choice profiling. Food Quality and Preference, 8, 381–388. del nobile, m.a., conte, a., incoronato, a.l., panza, o., sevi, a. and marino, r. (2009). New strategies for reducing the pork back-fat content in typical Italian salami. Meat Science, 81, 263–269. demeyer, d. and stahnke, l. (2002). Ch 18, Quality control of fermented meat products. In: J. Kerry, J. Kerry, and D. Ledward, editiors. Meat Processing; Improving quality. Cambridge: Woodhead, 359–382. desmond, e.m., troy, d.j. and buckley, d.j. (1998). The effects of tapioca starch, oat fibre and whey protein on the physical and sensory properties of low-fat beef burgers. Lebensmittel Wissenschaft und Technologie, 31, 653–657. desrochers, r. keane, p., ellis, s. and dowell, k. (2002). Expanding the sensitivity of conventional analytical techniques in quality control using sensory technology. Food Quality and Preference, 13, 397–407.

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

179

dethmers, a.e. and rock, h. (1975). Effect of added sodium nitrite on sensory quality and nitrosamine formation in Thuringer sausage. Journal of Food Science, 40, 491–495. dijksterhuis, g.b. (1995). Multivariate data analysis in sensory and consumer science: An overview of developments. Trends in Food Science & Technology, 6, 206–211. dijksterhuis, g. and byrne, d.v. (2005). Does the mind reflect the mouth? Sensory profiling and the future. Critical Reviews in Food Science and Nutrition, 45, 527–534. dransfield, e., nute g.r., roberts, t.a., boccard, r., touraille, c., buchter, l., et al. (1984). Beef quality assessed at European research centers. Meat Science, 1, 1–10. drumm, t.d. and spanier, a.m. (1991). Changes in the lipid content of autoxidation and sulphur-containing compounds in cooked beef during storage. Journal of Agriculture and Food Chemistry, 49, 336–343. eklöv, t., johansson, g., winquist, f. and lundström, i. (1998). Monitoring sausage fermentation using an electronic nose. Journal of Science and Food Agriculture, 76, 525–532. findlay, c. (2002). Computers and the Internet in sensory quality control. Food Quality and Preference, 13, 423–428. frandsen, l.w., dijksterhuis, g., brockhoff, p, nielsen, j.h. and martens, m. (2003). Subtle differences in milk: comparison of an analytical and an affective test. Food Quality and Preference, 14, 515–526. grigioni, g.m., margaria, c.a., pensel, n.a., sánchez, g. and vaudagna, s.r. (2000). Warmed-over flavour in low temperature-long time processed meat by an ‘electronic nose’. Meat Science, 56, 221–228. grunert, k.g., jensen, b.b. sonne, a.m., brunsø, k., byrne, d.v., clausen c., friis, a., holm, l., hyldig, g., kristensen, n.h., lettl, c. and scholderer, j. (2008) Useroriented innovation in the food sector: relevant streams of research and an agenda for future work. Trends in Food Science & Technology, 19, 590–602. guillevic, m., kouba, m. and mourot, j. (2009). Effect of a linseed diet on lipid composition, lipid peroxidation and consumer evaluation of French fresh and cooked pork meats. Meat Science, 81, 612–618. hansen, t., pedersen, m.a. and byrne, d.v. (2005) Sensory based quality control utilising an electronic nose and GC-MS analyses to predict end-product quality from raw materials. Meat Science, 69, 621–634. haugen, j.e. and kvaal, k. (1998). Electronic nose and artificial neural network. Meat Science, 49, S273–S286. iso (1992). International Standard. 5492. Sensory analysis-vocabulary. Ref. no. ISO 5492:1992 (E/F). International Organization for Standardization, Geneva. iso (1994). International Standard. 11035. Sensory analysis-identification and selection of descriptors establishing a sensory profile by a multidimensional approach. Ref. no. ISO 11035:1994 (E). International Organization for Standardization, Geneva. jeffery, a.b. and lewis, d.f. (1983). Studies on beef burgers. Part II: Effect of mincing plate size and temperature of the meat in the production of beef burgers. Leatherhead Food RA Report No. 439, pp. 7.12. johnson, p.b. and civille, g.v. (1986). A standardized lexicon of meat WOF descriptors. Journal of Sensory Studies, 1, 99–104. king, s., gillette, m., titman, d., adams, j. and ridgely, m. (2002). The Sensory Quality System: a global quality control solution. Food Quality and Preference, 13, 385–395. köster, e.p. (2003). The psychology of food choice: some often encountered fallacies. Food Quality and Preference, 14, 359–373. land, d.g. (1977). Flavour research in the ARC. ARC Research Review, 3, 58.

© Woodhead Publishing Limited, 2011

180

Processed meats

lawless, h.t. and heymann, h. (1998a). Sensory evaluation in quality control. In H.T. Lawless and H. Heymann. Sensory Evaluation of Food, Principles and Practices. New York: Chapman and Hall, 548–584. lawless, h.t. and heymann, h. (1998b). Descriptive analysis. In H.T. Lawless and H. Heymann. Sensory Evaluation of Food, Principles and Practices. New York: Chapman and Hall, 117–138, 341–378. liu, q., lanari, m.c. and schaefer, d.m. (1995). A review of dietary vitamin E supplementation for improvement of beef quality. Journal of Animal Science, 73, 3131–3140. loescher, e., sieffermann, j.m., pinguet, c., kesteloot, r. and cuvlier, g. (2001). Development of a list of textural attributes on pear/apple puree and fresh cheese: adaptation of the quantitative descriptive analysis method and use of flash profiling. 4th Pangborn, Dijon, France. lyon, b.g. (1987). Development of chicken flavour descriptive attribute terms aided by multivariate statistical procedures. Journal of Sensory Studies, 4, 55–67. macfie, h.j., bratchell, n., greenhoff, k. and vallis, l.v. (1989). Designs to balance the effect of order of presentation and first-order carry-over effects in hall tests. Journal of Sensory Studies, 4, 129–148. martens, h., and martens, m. (2001). Multivariate Analysis of Quality. An introduction. Chichester: J. Wiley and Sons Ltd, 139–145. martens, h., dijksterhuis, g.b. and byrne, d.v. (2000). Power of experimental designs, estimated by Monte Carlo simulation. Journal of Chemometrics, 14, 441–462. meilgaard, m.c., civille, g.v. and carr, b.t. (1991). Sensory Evaluation Techniques. Boston, MA: CRC Press. meilgaard, m.c., civille, g.v. and carr, b.t. (1999). In Sensory Evaluation Techniques, 3rd edition, Chapter 5. Florida: Academic Press, 54–55. mielche, m.m. and bertelsen, g. (1993). Effects of heat treatment on warmed-over flavour in ground beef during aerobic chill storage. Zeitschrift für Lebensmitteluntersuchung und Forschung A, 197(1), 8–13. miller, r. (1994). Sensory methods to evaluate muscle foods. In D.M. Klinsman, A.W. Kotula and B.C. Breidenstein. Muscle Foods: Meat Poultry and Seafood Technology. New York: Chapman and Hall, 333–360. montel, m.c., reitz, j., talon, r., berdagué j.l. and rousset, a.s. (1996). Biochemical activities of Micrococcaceae and their effects on the aromatic profiles and odours of a dry sausage model. Food Microbiology, 13, 489–499. moskowitz, h.r., beckley, j.h. and resurreccion, a.v.a. (2006). Sensory and Consumer Research in Product Development and Design. Blackwell Publishing, Iowa, USA. muñoz, a.m. (2002) Sensory evaluation in quality control: an overview, new developments and future opportunities. Food Quality and Preference, 13, 329–339. muñoz, a.m. and chambers i.v.e. (1993). Relating sensory measurements to consumer acceptance of meat products. Food Technology, 47, 128–131, 134. muñoz, a.m. and civille, g.v. (1992). The spectrum descriptive analysis method. In R.C. Hootman, ASTM Manual on Descriptive Analysis. Pennsylvania: American Society for Testing and Materials. muñoz, a.m., civille, g.v. and carr, b.t. (1992a). Comprehensive descriptive method. In: Sensory Evaluation in Quality Control, Van Nostrand Reinhold, New York, 55–82. muñoz, a.m., civille, g.v. and carr, b.t. (1992b). ‘In/Out’ method. In: Sensory Evaluation in Quality Control. Van Nostrand Reinhold, New York, 140–167. muñoz, a.m., civille, g.v. and carr, b.t. (1992c). Difference-from-control method (degree of difference). In: Sensory Evaluation in Quality Control. Van Nostrand Reinhold, New York, 168–205.

© Woodhead Publishing Limited, 2011

Use of sensory science as a practical commercial tool

181

nissen, l.r. and byrne, d.v. (2005). Sensory based control strategies in food production and development to achieve quality indexes. Pangborn Sensory Science Symposium, nr. 6, North Yorkshire, UK, 7–12 August 2005. nollet, l.m.l (2007). Part IV Beef quality. In Handbook of Meat, Poultry and Seafood Quality. Oxford: Blackwell Publishing ltd, 311–327. ólafsdóttir, g., martindóttir, e. and jónsson, e.h. (1997). Rapid gas sensor measurements to determine spoilage of capelin (Mallotus villosus). Journal of Agriculture and Food Chemistry, 45, 2654–2659. o’sullivan, m.g., byrne d.v. and martens, m. (2002). Data analytical methodologies in the development of a vocabulary for evaluation of meat quality. Journal of Sensory Studies, 17, 539–558. o’sullivan, m.g., byrne, d.v., nielsen, j.h., andersen, h.j. and martens, m. (2003a). Sensory and chemical assessment of pork supplemented with iron and vitamin E. Meat Science, 64, 175–189. o’sullivan, m.g., byrne, d.v., martens, h., gidskehaug, l.h, andersen, h.j. and martens, m. (2003b). Evaluation of pork meat colour: prediction of visual sensory quality of meat from instrumental and computer vision methods of colour analysis. Meat Science, 65, 909–918. o’sullivan, m.g., byrne, d.v., jensen, m.t., andersen, h.j. and vestergaard, j. (2003c). A comparison of warmed-over flavour in pork by sensory analysis, GC/MS and the electronic nose. Meat Science, 65, 1125–1138. pecore, s. and kellen, l. (2002). A consumer-focused QC/sensory programme in the food industry. Food Quality and Preference, 13, 369–374. peryam, d.r. and pilgrim, f.j. (1957). Hedonic scale method of measuring food preferences. Food Technology, 11(9), 9–14. pham, a.j., schilling, m.w., mikel, w.b., williams, j.b., martin, j.m. and coggins, p.c. (2008). Relationships between sensory descriptors, consumer acceptability and volatile flavor compounds of American dry-cured ham. Meat Science, 80, 728–737. piggott, j.r., simpson, s.j. and williams, s.a.r. (1998). Sensory analysis. International Journal of Food Science & Technology, 33(1), 7–12. pryzbylski, r. and eskin, n.a.m. (1995). Methods to measure volatile compounds and the flavour significance of volatile compounds. In K. Warner and N.A.M. Eskin. Methods to Assess Quality and Stability of Oils and Fat-Containing Foods. Illinois: AOCS Press, 107–133. rason, j., lebecque, a., leger, l. and dufour, e. (2003). Delineation of the sensory characteristics of traditional dry sausage. I – Typology of the traditional workshops in Massif Central. In The 5th Pangborn sensory science symposium, July 21–24, Boston, USA. resurreccion, a.v.a. (2004). Sensory aspects of consumer choices for meat and meat products. Meat Science, 66, 11–20. ross, c.f. (2009). Sensory science at the human–machine interface. Trends in Food Science & Technology, 20, 63–72. schilling, m.w. (2007). History, background, and objectives of sensory evaluation in muscle food. In L.M.L. Nollet, Handbook of Meat, Poultry and Seafood Quality. Oxford: Blackwell Publishing, 15–24. sieffermann j.-m. (2000). Le profil flash: un outil rapide et innovant d’évaluation sensoriel descriptive, Agoral 2000, 12ème rencontres, L’innovation: de l’idée au succés, 335–340. siegmund, b. and pfannhauser, w. (1999). Changes of the volatile fraction of cooked chicken meat during chill storing: results obtained by the electronic nose in comparison to GC-MS and GC olfactometry. Zeitschrift für LebensmittelUntersuchung und Forschung A, 208, 336–341.

© Woodhead Publishing Limited, 2011

182

Processed meats

st. angelo, a.j. and bailey, m.e. (1987). Warmed-over Flavor of Meat. Florida: Academic Press, vii–viii. st. angelo, a.j., crippen, k.l., depuy h.p. and james, c., jr. (1990). Chemical and sensory studies of antioxidant-treated beef. Journal of Food Science, 55, 1501–1539. stapelfeldt, h., bjorn, h., skovgaard, i.m., skibsted, l.h. and bertelsen, g. (1992). Warmed-over flavour in cooked sliced beef: chemical analysis in relation to sensory evaluation. Zeitschrift für Lebensmittel Untersuchung und Forschung, 195, 203–208. stewart-knox, b. and mitchell, p. (2003). What separates the winners from the losers in new food product development? Trends in Food Science and Technology, 14, 58–64. stolzenbach, s., lindahl, g., lundström, k., chen, g. and byrne, d.v. (2008). Perceptual masking of boar taint in swedish fermented sausdages. Meat Science, 81, 580–588. stone, h. and sidel, j.s. (1993). Sensory Evaluation Practices, 2nd ed. Orlando, FL: Academic Press, 327. stone, h., sidel, j., oliver, s., woolsey, a. and singleton, r.c. (1974). Sensory evaluation by quantitative descriptive analysis. Food Technology, 28, 24–34. tikk, k., haugen, j.e., andersen, h.j. and aaslyng, m.d. (2008). Monitoring of warmed-over flavour in pork using the electronic nose – correlation to sensory attributes and secondary lipid oxidation products. Meat Science, 80, 1254–1263. tims, m.j. and watts, b.m. (1958). Protection of cooked meats with phosphates. Food Technology, 12, 240–243. válková, v., saláková, a., buchtová, h. and tremlová, b. (2007). Chemical, instrumental and sensory characteristics of cooked pork ham. Meat Science, 77(4), 608–615. vestergaard, j.s., haugen, j.e. and byrne, d.v. (2006). Application of an electronic nose for measurements of boar taint in entire male pigs. Meat Science, 74, 564–577. weller, j.n. and stanton, k.j. (2002). The establishment and use of a QC analytical /descriptive/consumer measurement model for the routine evaluation of products at manufacturing facilities. Food Quality and Preference, 13, 375–383. wheeler, t.l., shackelford, s.d. and koohmaraie, m. (1997). Standardizing collection and interpretation of Warner–Bratzler shear force and sensory tenderness data. In Proceedings 50th Annual Reciprocal Meat Conference. Ames, IA, 68–77. zakrys-walliwander, p.i., o’sullivan, m.g., allen, p., o’neill, e.e and kerry, j.p. (2010). Investigation of the effects of commercial carcass suspension (24 and 48 hours) on meat quality in modified atmosphere packed beef steaks during chill storage. Food Research International, 43, 277–284.

© Woodhead Publishing Limited, 2011

8 Scientific modeling of blended meat products R. A. LaBudde, Least Cost Formulations Ltd, USA and T. C. Lanier, North Carolina State University, USA

Abstract: This chapter discusses the history and practice of least-cost formulation (LCF), with particular emphasis on the science-based formulation (SBF) models needed to control blended meat product properties. These properties include chemical, compositional, nutritional, functional, physical and flavor attributes. The current state of modeling of these properties is discussed, and the methodology illustrated by examples. Finally, the lack of continuing research and material characterization in the development of SBF technology is identified as the principal impediment to future progress in this important area of the application of meat science. Key words: least-cost formulation (LCF), science-based formulation (SBF), formulation, bind, linear programming.

8.1 Introduction This chapter deals with the subject of requirements-oriented formulation of blended meat products (fresh, cooked, dry and semi-dry sausage, mixed foods, pumped or marinated muscle foods). It does not, in general, apply to single-ingredient meat products that meet all requirements with a fixed formulation (steaks, chops, roasts) with no substitutability or level of use issues.

8.1.1 Requirement-oriented formulation The requirements for an acceptable formulated product derive from various sources. These include governmental regulations, safety, sensory qualities, producibility, logistics and cost. Governmental regulations apply in detail in many ways to formulation:

© Woodhead Publishing Limited, 2011

186 • • • • •

Processed meats

nutritional content and claims; order of predominance labeling; use of non-meat extenders (proteinaceous), binders and fillers; control of crude chemistry (fat, moisture, protein); and control of additive use (e.g., nitrite, erythorbate, phosphates).

Food safety is influenced by formulation by: (a) levels of key ingredients added specifically or partially for anti-microbial effect (salts, nitrite, essential oils, lactates, acetates, etc.); (b) non-inclusion of unlabeled allergens; and (c) impact of formula upon the ability to achieve lethality in processing (cf. ‘producibility’ below). Sensory qualities include internal color, external color, gel strength (e.g., peak stress or force to failure at fixed deformation rate), gel ductility (e.g., peak strain or deformation to failure at fixed deformation rate), saltiness, sweetness, pepperiness (heat), meatiness (meat flavor), juiciness and other flavor notes. Producibility requirements relate to the ability to make a particular meat product consistently, reliably and efficiently in practice. Such requirements include: • • • • • •

emulsion stability prior to gelation (‘cooking’); smoke acceptance; product strength (gel strength generally, peelability, sliceability); dimensional stability (non-bloating); syneresis stability (post-packaging exudate); and shelf-life stability.

Logistical requirements involve making sure that particular ingredients and lots of ingredients are selected from those expected to be available at the time of production. Finally, cost has played, and will continue to play for some time to come, a critical role in the acceptability of processed meat products to institutional customers and to consumers. The meat industry remains highly competitive, with a plethora of processors soliciting the business of a limited number of key customers. Cost determines profit in a competitive environment where sales prices and order volumes are fixed.

8.1.2

Science-based formulation (SBF), computer-assisted formulation (CAF) and least-cost formulation (LCF) We will primarily be interested here in ‘science-based formulation’ (SBF), where the role of requirements is dominant, and quantification and modeling of such requirements in order to achieve control are key issues. However, the calculations necessary for these activities inevitably brings a connection to ‘computer-assisted formulation’ (CAF), and the important commercial issue of optimizing profit has inexorably linked SBF and CAF to ‘least-cost formulation’ (LCF). The CAF tool for implementing SBF has traditionally

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

187

been LCF. LCF also deals with more complex and wider issues of purchasing selections, production scheduling, quality control and materials management, none of which will be discussed here other than tangentially. SBF as defined here involves three primary tasks: 1. Reducing requirements to (at least theoretically) measurable quantitative variables. 2. Modeling the requirement variables by (typically linear) functions of the formula input variables (viz., the ingredient proportions or weights). 3. Setting critical limits on the requirement variables such that any formula which meets such limits is considered satisfactory in production. Once this ‘product specification’ is set, a tool such as LCF (described in more detail below) is used to down-select to a specific formula meeting these and other requirements.

8.1.3 History of LCF and SBF in the meat industry Wars have always been the impetus for the greatest strides in food science because, in the words of Napoleon, ‘une armée marche à son estomac’. The fermented dry sausage may have been the end product of a search for portable, shelf-stable rations by the Roman legions. Hard tack and salt pork were staples of armies from the seventeenth to the nineteenth centuries. Canned food was an outgrowth of the Napoleonic wars. The roots of modern SBF and LCF were in World War II. This war encompassed the world with multiple theaters of action, and was a nightmare of logistics. There were three key inventions that grew out of WWII that are germane to the discussion here: 1. The first coherent statement of SBF. 2. The invention of ‘linear programming’ problem solution methods. 3. The digital computer. Exposition of these inventions, which were ‘secret’ during the war, did not occur until 1945–1947. George Stigler (later to receive a Nobel prize in economics) and his group worked on the optimization of nutrition for the diets of soldiers. In Stigler (1945), the ‘Diet Problem’ for human nutrition was discussed and formulated. He presented the first LCF solutions published, calculated by hand. George Dantzig and his group worked on solving logistics problems related to distribution of supplies and factory scheduling. Just after WWII he developed the ‘simplex method’ algorithm for solving large-scale ‘linear programs’ (i.e., optimization problems phrased as systems of linear inequalities, ‘program’ = ‘schedule’). Dantzig (1963) presents an extensive history of events and publications in this area. Interestingly, he also relates how Jack Laderman of the Mathematical Tables Project of the US National

© Woodhead Publishing Limited, 2011

188

Processed meats

Bureau of Standards (now National Institute of Standards and Technology) had a team of nine clerks solve Stigler’s Diet Problem with hand calculators. It took the team 120 man-days of effort to find an optimum solution. The digital computer was invented during WWII in order to perform simulations of nuclear fission chain reactions (in order to verify that an atomic bomb test would not ignite the atmosphere of the Earth in a fusion reaction). The inventors of the ‘ENIAC’ computer, Drs Eckert and Mauchley, went on to found the Univac Corporation to commercialize their invention. Their first ‘UNIVAC’ computer was delivered to the US Census Bureau (which since the nineteenth century has been a driver of computing technology) at a cost of US $1 million. There is an anecdotal story that Univac in the early 1950s decided that the market for digital computers in industry was too small (projected at 10 units per year at a $10 million price tag each), and the product was too unreliable (using 20,000+ vacuum tubes with random lifetimes). So Univac decided to get out of the computer business. At the same time, IBM, looking forward to transistor technology (another outgrowth of research of WWII), decided to get into the computer business. (In fact, IBM had been involved with the invention of the digital computer during WWII, and had systematically been continuing attempts to commercialize the device, so the story is probably apocryphal or distorted.) Progress was fast: in 1951 IBM released the 701 model, and the FORTRAN scientific ‘high-level’ program language followed. In 1956, the 704 model incorporated floating-point arithmetic, which, together with the FORTRAN language for programming, allowed practical solutions of reasonable size linear programming problems. Because of the cost of digital computers during this era, IBM used its new scientific capabilities and the new LCF methodology to sell computers across a wide range of blending industries as a way to cut cost of materials by 5–10%, doubling a typical company’s net profit, and thereby getting the accounting and payroll departments a computer for ‘free’. Use of LCF in the blending industries increased rapidly along with lowered costs of digital computers due first to transistor technology, and then integrated circuits in the 1960s. These events are chronicled in Charnes and Cooper (1961) and Danø (1974). During the period 1955–1975, LCF became solidly entrenched throughout the larger companies in the meat industry for solving sausage formulation problems. The need for SBF became evident early on, as some candidate meat ingredients were very high in connective tissue and low in functionality, and others were high in contractile muscle tissue and functionality, so substitutability was restricted. The postulation and solution of LCF problems for sausage and other blended meat products could not be done reliably until the general texture (gel strength) of the cooked batter could be predicted. This property was traditionally known as the ‘bind’ or ‘binding ability’ of a meat, and known

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

189

to be high in skeletal muscle meat and low in ‘filler’ or high connective tissue meat. To a lesser extent, predicting the ‘color’ (pigment) of the resulting blend was also desirable. Very occasionally, the term ‘bite’ was used to indicate the shear stress needed to break the skin or casing of a link sausage product, but ‘bite’ was primarily a property of the processing schedule in cooking and of the type of casing used. To a sausagemaker, both fat and water binding were encompassed in the term ‘bind’. The first attempts at SBF to provide predictors of ‘bind’ and ‘color’ were based upon ad hoc subjective estimates of the quality of different meat sources relative to a standard of comparison, typically bull meat, which was judged the most functional meat commonly available for sausage applications. Anderson and Clifton (1967) provides one such scale, where bull meat is denoted by the value 1.00 for either ‘bind’ or ‘color’, and other meats are assigned values in multiples of 0.05. The Anderson–Clifton tables are reproduced in Pearson and Tauber (1984). Perhaps surprisingly, such ad hoc assignment of values to a functional attribute actually works sufficiently well to control the needed function in LCF. All that is needed is a reasonable degree of correctness in assessing the ratio scale of measurement among the candidate ingredients. In the 1960s, the ‘emulsion’ theory of sausage products became in vogue. It was believed that salt-soluble protein ‘encapsulated’ fat globules, providing ‘stability’ to the fat-in-water emulsion of the sausage product, and this was the basis of product texture (‘bind’). So the search for a SBF attribute to use for ‘bind’ focused on salt-soluble protein and emulsion stability. Swift et al. (1961) and Swift (1965) provided an ad hoc method that allowed oil titration of emulsion stability. This was followed by a well-designed series of experiments by Saffle and coworkers, reviewed in Saffle (1968). The laboratory methods are particularly well-described in Carpenter and Saffle (1964). The ‘Saffle’ or ‘University of Georgia’ bind and color models rapidly became the norm for LCF of sausage products, and were viewed as a triumph of SBF modeling. (For a historical and scientific review, with an extensive table of values, see LaBudde and Lanier, 1995, also Anon, 1970, Porteous, 1979, LaBudde, 1991, Gordon and Barbut, 1992.) Beginning in the 1980s, it became increasingly clear that the ‘emulsion stability’ model for sausage products was of limited value in explaining cooked product properties, such as texture and water and fat binding (Comer and Dempster, 1981, Lanier, 1985, Regenstein, 1988, 1989). The ‘gel’ theory of cooked meat products became ascendant (see review in LaBudde, 1992, also Lanier and LaBudde, 1993, and Lanier et al. 1993). In LaBudde and Lanier (1995), a framework for SBF is postulated, based upon statistical analysis of linear mixture models and upon finished product measurements. From a standardized series of experiments on different mixtures, the effect of a particular ingredient can be inferred based on an input–output model. Using a torsion gelometer, the ultimate gel strength and ultimate gel strain were measured, and coefficients determined for more than a dozen different

© Woodhead Publishing Limited, 2011

190

Processed meats

meat ingredients in multiple lots. The Saffle ‘bind’ constants were found to correlate well with the coefficients derived from finished product ultimate gel strength, and with non-collagen soluble protein, the underlying connector between the emulsion and gelation theories. The new approach was found to have four principal scientific benefits: 1. Causality. The strength and strain coefficients are based on measurements of a finished product (highly predictive of actual smokehouse product), not results of testing a model system. The test system derives from recognition that protein gelation and entrapment of constituents, rather than emulsification of fat, is the primary determinant of product stability and texture. 2. Validity. Rather than a vague ‘bind assessment’, prediction of actual product attributes (texture, liquid retention) are made by the new ‘coefficients’. Predicted results can be easily validated by measurements on the actual finished product. 3. Applicability. Not only meat ingredients, but all other ingredients can have their effects estimated by the new methodology. Even the effects of processing variables can be assessed. 4. Reproducibility. The new methodology is based on well-defined, fundamental test methods derived from material science and engineering, capable of being reproducibly performed in independent laboratories. SBF was extended in the 1990s to water-holding capacity (WHC), meat flavor, thermal properties, and response to certain processing variables (LaBudde, 1991; LaBudde and Lanier, 1995). Sporadic work continues in some of these areas, particularly WHC (see Pouttu and Puolanne, 2003).

8.2 The least-cost formulation (LCF) model Although the focus of this chapter is on SBF, this depends upon a foundation of the well-established methodology of LCF to achieve solutions in practice. So it is necessary to first understand the principles of LCF and its assumptions and limitations before going into the more specific details of SBF of blended meat products.

8.2.1 Central assumptions The reduction to practice of a new process involves traditionally three stages: research; development; and manufacturing. Research answers the questions ‘Is it possible and, if so, how?’ A search for optimum parameters is generally involved, and the use of science (modeling, experimentation and analysis). Sometimes nonlinear models (e.g., response surface methodology) are needed to find reasonable starting sets of parameters and a region for subsequent investigation.

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

191

Development (‘engineering’) answers the question ‘How can it be done best?’ Established engineering models, almost invariably linear, are used to fine-tune parameters, such as blend formulae or process variables. Manufacturing deals with the question ‘Can it be done the same way, batch after batch, day after day?’ Management and specifications are used to get employees and materials to accomplish consistent and predictable production. Manufacturing models are characterized by very flat optima, where modest changes in parameters result in near identical results. If this were not true, management of the process and personnel would be extremely difficult. LCF is a type of ‘engineering’ (linear modeling) that unfortunately intrudes upon ‘manufacturing’ (constant procedures) on a batch-by-batch basis, requiring changes in blend formulae. Because of the variability of the different lots of materials (particularly meats), a fixed (constant) blend formula will result in variable product qualities as different material lots are used. Constant product quality can only be attained by variable blend formulae. Material variation must be ‘blended out’ if the product batches are to be consistent in quality. Conservation: ‘What goes in is what comes out.’ The principal assumption in LCF is that product quality is due (for the most part) to material attributes. That is, the product attributes are predictable from the blend formula and the material attributes. This is obviously not true for certain quality attributes, which may be heavily influenced, e.g., by processing. Consider, for example, bacterial contamination of a unit of finished product. For raw product, such as ground beef or fresh pork sausage, the bacteria present in materials will carry forward into the final product. But there may be modulation due to handling or cryogenic chilling and certainly to storage conditions. For cooked product, the ingoing load of bacteria in raw materials is almost unimportant compared with degree of cooking and post-cook environmental recontamination. So, generally, microbiological contamination is not a ‘formulatable’ attribute of a product. (Here we define ‘formulatable’ as predictable via a linear input–output model based upon blend formula proportions and material attributes.) This assumption does hold true for a remarkably large set of attributes, including chemistry (moisture, fat, protein, salt), nutrients and functional properties. Some of these (e.g., moisture, salt) are typically modulated to some extent by processing variables, which sometimes must be dealt with explicitly in LCF. Linearity Traditionally, LCF has been used with only linear models, which makes the constraints weighted averages of material attributes, e.g., the protein content of the finished product is the weighted average of the protein content of each material used. The places LCF in the ‘engineering model’ regime.

© Woodhead Publishing Limited, 2011

192

Processed meats

Although LCF could be performed using quadratic or more nonlinear models (see, e.g., Hsu et al., 1996), there are many reasons why this is impractical or undesirable. Firstly, such models are difficult to understand and interpret, which therefore makes it difficult to train manufacturing personnel to use on a daily basis or even to train food technologists to use for development work. Secondly, models nonlinear in parameters are unstable with respect to starting conditions and incremental changes. A small change in a parameter may result in a large change in result. Thirdly, models nonlinear in parameters may not have an easily found optimum, particularly if initial guesses as to formula proportions and parameters are not accurate enough. Fourthly, solving nonlinear optimization models is timeconsuming and troublesome, and this increases dramatically with the size of the model. Problems solved routinely in manufacturing in a meat processing facility may involve hundreds of variables and hundreds of constraints, and this size of nonlinear problem is generally impractical to deal with on a recurring basis. Finally, nonlinear models, even those linear in parameters, rarely have enough robustness or external validity to generalize to the variations and substitutions present in practical application. Linear models are much more likely to be valid in modest extrapolation. It should be noted that the great majority of food science research articles published involve linear (in both variables and parameters) models analyzed, e.g., by multiple linear regression or analysis of variance techniques. When a process is further optimized by engineering development and reduced to practice in manufacturing, the process parameters are typically positioned at some type of optimum where variation in parameters induces only a slight change in output. For manufacturable products, a linear model is thus sufficiently accurate to control quality. Continuity Another traditional assumption made in LCF is that material weights in a blend are continuous variables and not, say, limited to integral values. This assumption greatly simplifies the search for a solution. The most common case where this assumption is limiting is where frozen meats are used in a small batch size. Frozen meat is used in ‘box’-sized increments, typically 20 kg or 60 lb. If the batch size is less than 10 times this unit of measure, the solution based on continuous weights may be inaccurate. The problem is exacerbated if several such ingredients are present in the blend. Typically, when the unit of measure is only a small fraction of the blend weight, the problem is dealt with approximately by ‘rounding after formulation’ the ingredient weights to the nearest multiple of the box size. Incorporation of discrete material weights into the model requires solution by integer programming techniques, essentially involving a collection of linear programming solutions whose number increases exponentially with the number of discrete combinations possible.

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

193

8.2.2 Product formula input–output model Let ‘A’ denote some attribute per kg of a raw material (input), and wi denote the mass in the blend formula of the ith material. Within the framework of the above assumptions, the linear product formula input–output model for the kg of attribute ‘A’ of the blend (output) is then kg A = w1 A1 + w2 A2 + ... + wn An

8.1

This form, although basic to the LCF model, requires adjustment in many cases for process losses to be practically useful, and needs to be scaled to a mass base to apply problem-level constraints. As an example of this, eq. (8.1) gives the basic input–output model for the situation in which the process of conversion of materials to a blended product conserves kg of A, e.g., a simple blend step. But in practice the model must have a greater reach to be representative of a real finished product. In particular, cooked meat products are significantly affected by moisture loss (so-called ‘shrink’) in the process. Such cook losses range from 1–3% for large diameter permeable casings (e.g., bologna) to 25% or more for dry sausage and small diameter casings (e.g., snack sticks). Large shrink losses must be included explicitly in the model to obtain accurate predictions. Shrink loss or gain Let ‘GW’ denote the gross blend mass, or ‘gross weight’, GW = w1 + w2 + ... + wn

8.2

Typically it is assumed that the shrink loss for a given process is a constant fraction ‘s’ of the blend weight GW. (If there were an interaction between the shrink loss and the masses wi of the materials, the model would become nonlinear due to cross-terms.) Suppose further that a fraction γA of the shrink mass loss is lost from the attribute A. Then eq. (8.1) needs to be modified to kg A = w1 A1 + w2 A2 + ... + wn An − γA s GW

8.3

in order to estimate the kg of A post-process in the finished product batch. Finally, the total kg of attribute A in the finished product batch is not as relevant in specification units as the amount of attribute A in the finished product, per kg of some specified mass base. The mass bases of most interest are generally gross weight (GW), finished weight (FW), meat weight (MW) or serving weight (SW). GW is defined by eq. (8.2) above, and the others typically by FW = (1 − s) GW

8.4

MW = w1 μ1 + w2 μ2 + ... + wn μn

8.5

SW = η FW

8.6

© Woodhead Publishing Limited, 2011

194

Processed meats

where μi = 1 if the material is a ‘meat’ and 0 otherwise, s is the shrink fraction defined above, and η is the conversion factor from a kg to the specific nutritional labeling serving size for the product, e.g., for a 57 g serving, η = 57/1000 = 0.057. Now the attribute A content of the product blend can be phrased more accurately and per mass base via, e.g., w1 A1 + w2 A2 + … + wn An − γ A s GW 8.7 FW Suppose the fat content (as a fraction) is denoted by F. For a typical meat product, the fraction γF = 0 (although exceptions might be cooked ground beef, cooked pork sausage or cooked bacon), so the fat content of the finished product would be modeled by A=

F=

w1 F1 + w2 F2 + … + wn Fn FW

8.8

Similarly, for protein content P, the fraction γP = 0, and P=

w1 P1 + w2 P2 + … + wn Pn FW

8.9

For permeably cased product, where the cook loss is dominated by moisture, the moisture content M has fraction γM = 1, and M=

w1 P1 + w2 P2 + … + wn Pn − s GW FW

8.10

Occasionally the process increases weight instead of reducing it, so ‘loss’ is a misnomer. For example, in the steam extrusion or immersion cooking in water of some foods, a net weight can occur, and either s < 0 or γM < 0. In sausage production which incorporates a brine chill post-cook, frequently salt (i.e., NaCl) pickup occurs if the salt activity of the brine exceeds that of the product itself (typically +0.3% weight for a 10–15% brine), so γS < 0 (or −0.03 for a 10–15% brine and a product with s = 0.10 loss). If the total ‘shrink’ loss or gain is divided among various components of chemistry, there is a constraint that the total multiplication factor: γ = γ M + γ F + γ P + γ S +…

8.11

must equal 1.0 for the shrink loss or gain s to give the correct total weight change in GW. Conceptually, it is simplest to think of s giving the total fractional weight loss (+) or gain (−) in GW, and γA chosen such that γA s GW gives the total kg loss (+) or gain (−) in attribute ‘A’. Other process effects There are other situations besides processing losses (gains) where the postulate of conservation might be violated, and so which must be handled explic-

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

195

itly as a model adjustment. So far, such features have not been generally necessary to formulate blended meat products. Examples might include the impact of thermal treatment on microbiology or labile nutrients (e.g., microbiology, vitamin C, nitrite). Typically these are assumed to be subject to a constant effect, and dealt with separately from formulation for simplicity. 8.2.3 Prices LCF is an optimization problem. It assumes that orders (sales) are known, therefore production volume is known, and the way to maximize profits is to minimize the cost of production. In a typical blended meat product, meat comprises typically 50–70% of total direct costs. The other direct costs (labor, labels, packaging, equipment usage) can reasonably be assumed constant per unit of production, and so are not important in LCF. There are a number of economic assumptions implicit in the previous paragraph, which are important to the use of LCF as a management tool, but not to SBF, which is our principal focus here, so details of economicsbased modeling for LCF will not be given further. However, one thing must be said about the ‘costs’ used in least-‘cost’ formulation. Although traditionally the word ‘cost’ has been used in terminology, LCF is a planning tool, and therefore operates prospectively, not retrospectively. Under the assumption that the producing entity is a ‘going concern’, the ‘cost’ that must be minimized is the cost of obtaining of materials and the replenishment of stores after the planned production takes place. Thus the issue is one of ‘replacement’ cost, not ‘historical’ cost. In English-speaking countries, the word ‘cost’ generally connotes an auditable value for a transaction that took place in the past, and ‘price’ as the prospective value that would be paid if a future transaction were to take place. ‘Prices’, and not ‘costs’, are generally what are of interest in LCF. The use of prospective vs. retrospective is critical, because otherwise the real cost of production may be increased rather than reduced in the optimization. An example of this would be in the usage of stored inventories of frozen meat. If use does not occur, a holding cost will be incurred. Accounting principles require that this holding cost be added to the cost of the material. However, from an LCF point of view, if the material were to be used, the cost will be saved, and so the cost is properly to be subtracted from the cost of the material in formulation. This reversal of policy is characteristic of the difference between retrospective accounting and prospective decision-making. Following the accounting policy in this example would result in diminished usage when increased usage would have been the correct decision. 8.2.4 Availabilities Every real problem involves limited resources. This must be taken into account in LCF as well. A scarce material may be available at low cost, but

© Woodhead Publishing Limited, 2011

196

Processed meats

only in very limited quantities. If cost alone is used as a deciding point, a formula with high percentage of that material will be chosen by LCF, and the formula will be unsustainable in practice. Similarly, materials in inventory, such as frozen meat, may temporarily appear to be in great supply, but excessive use in formulae will result in ‘feast and famine’ cycles of replenishment. Generally only materials available on short notice in the open market should be viewed as freely available. Other materials (in-house trimmings, frozen inventories, low volume lots) are best handled by capping their usage in the formula. As an example, suppose that frozen beef is expected to have an approximate 24 week usable lifetime in storage, calculated as 48 weeks from kill, minus 12 weeks for product shelf-life, minus 12 weeks for acquisition and delivery. Then one method of physical flow is to force a minimum usage of exactly 1/24 of the amount in inventory each week of production. The upper limit on usage would depend upon the ability of production to properly stage and temper the meat before use.

8.3 Linear science-based models for meat product properties The heart of the use of SBF is the characterization of the attributes of raw materials and the use of these attributes, as well as logical relationships among materials, to set product requirements such that automatic formulation results in a practically acceptable formula. In setting a product specification, there are generally three methods of controlling product attributes. The most primitive is to attempt to fix the usage of individual ingredients within some range that generally results in acceptable product batches. This is conceptually easy to do, and appeals to the unsophisticated modeler, but ignores the substitutability of materials and severely restricts choice. So control is poor using this method, unless the material constrained has obviously constant unique properties, unlike those of any other material. This method is used in practice for controlled ingredients (such as curing agents and accelerators), starter culture, seasonings, etc., but is not advisable for meats. A more acceptable method of setting a product requirement is to constrain the usage, not of individual materials, but of a group of similar-acting materials. This categorical grouping of materials works well for labeling, where, e.g., all meats labeled ‘beef’ are considered equivalent by a regulatory agency, but ignores differing functional or chemical effects among different ingredients. The most precise and scientific (i.e., model- and evidence-based) method of control is to base a product requirement upon material attributes, which allows the weighted average of all material effects to be controlled.

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

197

As an example, consider one of the first major issues in SBF of blended meat products: the control of the ‘firmness’ (‘gel strength’) of finished cooked sausage. Sausage makers had long known that some meats (such as lean skeletal meat) had good ‘binding’ ability (i.e., their inclusion creates firmer texture) and others (such as high connective tissue meat) had poor ‘binding’ ability, and were considered simply ‘fillers’. So the first attempts at LCF limited ingredients such as snouts, lips and head meat individually to, say, 10% of the total blend. But if all three meats entered a formula, the individual limits still allowed 30% of the formula from the combination of them. Obviously the next step would be to place a 10% usage limit on the ‘group’ of ‘filler’ meats, so that the combination of them would never exceed 10% of the formula. Later, through the pioneering work of Saffle (see Section 8.3.5 below), these compositional controls were replaced with more scientific ones based upon experimentally measured coefficients for each meat’s ‘binding ability’ attribute, termed ‘bind values’, ‘bind indices’ or ‘bind coefficients’.

8.3.1 Mixture models The conservation model form of eq. (8.1) is identical to that of the linear statistical ‘mixture’ model (Cornell, 2002): E[y] = a1 x1 + a2 x2 + a3 x3 + ... + an xn

8.12

where E[y] is the expected value of y, y is some measured attribute, a1 ... an are coefficients, and x1 ... xn are a set of values of predictor variables constrained by, e.g., x1 + x2 + ... + xn = 1

8.13

With the right-hand side of eq. (8.13) being 1.0, the x1 ... xn are fractional composition variables. In eq. (8.1) as written, the w1 ... wn would total instead the GW in kg. The two forms are equivalent in the sense that they are simply scaled versions of each other, i.e., xi = wi/GW

8.14

A typical experiment (as in LaBudde and Lanier, 1995) would be to make blends with linearly independent formulae (i.e., {xi}), make measurements of the response variable y for each, and statistically reduce the data using the mixture model form of eq. (8.12). This is most conveniently done by multiple linear regression with no intercept, which is eliminated by the constraint eq. (8.13). The values of the attribute ‘A’ used in the SBF model for the raw materials would be the fitted coefficients {ai} in eq. (8.12). A nonlinear mixture model would include, e.g., interaction terms of the form xi xj and quadratic terms of the form xi2. As mentioned on pages 191–2, models nonlinear in variables or parameters are rarely necessary in modeling products reduced to manufacturing practice, and are difficult enough to

© Woodhead Publishing Limited, 2011

198

Processed meats

deal with and interpret even in a research setting. A crude linear model at the manufacturing operating point is generally preferable to a more accurate nonlinear model for most practical purposes. Interaction terms in formulation are typically necessary only when ingredients chemically react or interact, and such issues are antithetic to manufacturability. As an example, consider a meat product that contains both a starch and a gum. If the starch composition were raised to 90% of the blend, there would obviously be insufficient moisture present (moisture must be 100% − 90% = 10% or less) to hydrate the starch, let alone the gum. If the gum were raised to 90%, the same problem would recur, this time more severely, as the gum would likely have an even greater affinity for water. Clearly there must be interaction terms present between the starch, gum and moisture fractions in the blend. If we allow the entire range of variability (0 to 100%), these interactions will likely be present at high orders. But if we keep in mind the product involved is supposed to be a meat product of a known type, it is highly unlikely that either starch or gum will be allowed to be present at more than a few percent of the blend. Otherwise the fundamental character of the product would shift. By the very nature of manufacturability and the maintenance of product identity, all changes possible by allowed shifts in material fractions must cause relatively small shifts in product character. This makes the situation by definition a first-order effects model, typically represented by a linear model by virtue of Taylor’s theorem in mathematics. It is not that nonlinear models are not possible, it is just that they are not allowed in manufacturing. If a meat product is manufacturable, it must be controllable by a linear model. Otherwise it has not yet been reduced to manufacturing, and will not work in practice. One of the major problems in SBF is the obtaining of the attribute levels {ai} for all ingredients, both meat and non-meat, eligible for use in formulae. The ideal method to obtain these estimates is via a lot-replicated designed mixture model experiment which involves direct measurements on finished product. However, these types of experiment are costly, as they involve testing many individual blends, and have scale-up issues relating to the methods used to simulate preparation and cooking in the laboratory. More economical is to make direct measurements upon individual ingredients or comparisons between ingredients (and not blends of them), but this has issues of generalizability, as methods designed for meats are difficult to apply to non-meat ingredients, and vice versa. So, perforce, the starting point for non-easily measured attributes has historically been educated guesses. This easily applied, but subjective, method works as follows: an arbitrary scale is established, with some ingredient chosen as a standard of comparison, and assigned a value on the scale (e.g., bull meat as 1.0). Other ingredients are subjectively assigned values based upon experience of usage. These subjectively defined attributes, although not optimal, work surprisingly well in practice, if designed intelligently. The attribute levels can be approximately validated by formulating

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

199

substitution blends, and verifying that the property of interest is not significantly different. If it is, the assigned value can be increased or decreased in the direction of interest, and re-validated. This works fairly well for meats. Non-meat ingredients are then either ignored, or assigned values based upon ingredient supplier estimates of substitutability for meats.

8.3.2 Crude chemistry (proximate analysis) Generally chemistry attributes are conserved, and so follow the form of eq. (8.7) with the shrink-effect adjustment. This includes moisture, fat, protein, ash, salts and carbohydrates, and such derived quantities as ‘USDA Added Water’ defined by regulation in the USA as USDA AW = Moisture − 4 Protein

8.15

when the non-meat protein is less than 1% FW, and USDA AW = Moisture − 4 Meat Protein − 0.04

8.16

when the non-meat protein exceeds 1% FW. The proper ‘shrink-effect’ factor γ for eq. (8.15) is 1.0 and for eq. (8.16) is 0.96. Two of the three constituents – moisture, fat and protein – must be constrained to control product chemistry. (Salts and carbohydrates are typically subject to fixed limits.) In the USA this is accomplished by regulations on fat and ‘USDA Added Water’. Some other countries use moisture and protein. Table 8.1 lists the crude chemistry of a sample set of materials (ingredients).

8.3.3 Compositional groupings (logical relationships) For product identity and regulatory order of predominance labeling, certain logical groupings of materials must be defined. Examples include ‘beef’, ‘pork’, ‘chicken’ and ‘turkey’. Customer requirements may specify limits on mechanically separated or frozen meats. Such logical groups can be implemented by defining an associated attribute, e.g., ‘Beef’, which has values of 1.0 if the material is classified as ‘beef’ on the label, and 0.0 if it is not. Work-in-process composite materials (e.g., preblends) will have fractional values between 0 and 1. Some LCF systems (such as the Least Cost Formulator™ from Least Cost Formulations, Ltd) deal with groups of materials in a simpler manner by assigning individual ‘group letters’ to materials (e.g., ‘B’ for ‘beef’), with a hidden attribute dynamically constructed based upon the associations. Table 8.1 shows the logical relationship among materials as common ‘group’ letters. For example, materials having the common group letter ‘B’ are those qualifying as ‘Beef’ on the label ingredient statement in the USA. Similarly ‘P’ indicates ‘Pork’, ‘C’ indicates ‘Mechanically separated chicken’ and ‘T’ indicates ‘Mechanically separated turkey’.

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

BF50 BZ50 BF85 BZ85 BF90 BZ90 BFBULL BZCHEEK BZHEAD CFMSM15 CFMSM18 CFMSM22 PF42 PF72 PZCHEEK PFHAM

ID

BF FRSH 50% TRIM BF FROZ 50% TRIM BF FRSH 85% TRIM BF FROZ 85% TRIM BF FRSH 90% TRIM BF FROZ 90% TRIM BF FRSH FC BULL MT BF FROZ CHEEK MT BF FROZ HEAD MT CK FRSH MSM 15% FAT CK FRSH MSM 18% FAT CK FRSH MSM 22% FAT PF FRSH 42% TRIM PK FRSH 72% TRIM PK FROZ CHEEK MT PK FRSH 95% BNLS HAM

Description B BZ B BZ B BZ B BZ BZ C C C P P PZ P

Groups 0.4034 0.4034 0.6580 0.6580 0.6912 0.6912 0.7080 0.6309 0.6800 0.6812 0.6620 0.6376 0.3581 0.5707 0.6580 0.7430

Moisture (g/g) 0.4801 0.4801 0.1491 0.1491 0.1123 0.1123 0.0820 0.1914 0.1226 0.1339 0.1724 0.2063 0.5412 0.2707 0.1631 0.0500

Fat (g/g) 0.1114 0.1114 0.1897 0.1897 0.1886 0.1886 0.2020 0.1716 0.1911 0.1499 0.1324 0.1247 0.0958 0.1528 0.1770 0.1990

Protein (g/g)

0.0200 0.0200 0.0200

Salt (g/g)

0.00015 0.00015 0.00015

Nitrite (g/g)

Carbo (g/g)

0.4499 0.4499 0.8698 0.8900 0.9298 0.9500 1.0197 0.6998 0.4999 0.2199 0.1899 0.1700 0.3799 0.6398 0.6798 1.1626

Cost ($/lb)

Table 8.1 Sample material chemical analyses and costs for use in least-cost formulations. ‘Nitrite’ is NaNO2 content. Individual group letters indicate relational associations (see text)

© Woodhead Publishing Limited, 2011

PK FROZ HEAD MT PK FROZ HEAD MT TK FROZ MSM 20% FAT TAP WATER SOY PROTEIN ISOLATE MODIFIED CORN STARCH AUTOLYZED YEAST CORN SYRUP CORN SYRUP SOLIDS DRY CURE (PRAGUE PWD DEXTROSE SODIUM ERYTHORBATE SODIUM LACTATE SODIUM NITRITE SALT SODIUM TRIPOLYPHOS FLAVORINGS MUSTARD FLOUR SPICE

PZ PZ TZ WN XN XN XN N N N N N N N N N N N N 0.1000 0.0600 0.1000

0.4000

0.0800

0.5550 0.3622 0.6909 1.0000 0.0600 0.0832 0.0300 0.2000 0.0350

Note: Copyright © 1991 by Least Cost Formulations, Ltd., reprinted by permission.

PZHEAD1 PZHEAD2 TZMSM20 WATER XISP XSTRCHCM XYEAST YCORN YCSS YCURE YDEXT YERYTH YLACTATE YNITRITE YSALT YSTPP ZFLAV ZMUST ZSPICE 0.1200 0.3200 0.1200

0.8550 0.0026 0.5100

0.0100 0.0005

0.2500

0.1474 0.1100 0.1329

0.2910 0.5244 0.1596

1.0000

0.9375

1.00000

0.06250

0.7700 0.3650 0.7700

0.9200

0.0300 0.9128 0.4500 0.8000 0.9650

0.5199 0.3799 0.2299 0.0020 1.4496 0.2900 1.3696 0.1500 0.1800 0.2999 0.2399 2.9992 0.9997 0.8498 0.0500 0.6498 0.8998 0.3099 0.8998

202

Processed meats

8.3.4 Nutritional content Generally, nutrients, such as ‘calories’, ‘fat’, ‘saturated fat’, ‘sugars’, ‘sodium’, etc., are conserved, and are handled the same as the crude chemistry attributes of Section 8.3.2. Exceptions to conservation might be ‘sodium’, which can be increased slightly by brine chilling, and ‘vitamin C’, which is typically depleted severely in cooking. These special effects are usually dealt with most easily by standard post-formulation adjustment in values before constructing nutritional labels. Table 8.2 shows selected nutritional contents of the sample materials.

8.3.5 Functional attributes As of the current time, the functional attributes most commonly controlled in formulation are ‘bind’ (firmness, or gel strength), internal ‘color’ (pigmentation) and ‘WHC’ (water-holding capacity). Of these, the most important to cooked meat product formulation is ‘bind’. As mentioned above, the first approach to controlling ‘bind’ was to individually or collectively control the usage of ‘filler’ (i.e., poor binding) meats in the formula. After some experience with early use of LCF for blended meat products, consultants started providing subjectively-derived attributes for ‘bind’ and ‘color’. (See Anderson and Clifton, 1967, reproduced in Pearson and Tauber, 1974.) Then the pioneering work of Saffle and co-workers (Carpenter and Saffle, 1964; Saffle et al., 1967; Saffle, 1968) provided ‘bind’ attributes based upon oil titration of salt-soluble protein in meat ingredients. This was the first time that designed experiments with an underlying model was used to attempt to measure an attribute across a wide range of materials, and was a key milestone in the birth of SBF. Porteous (1979) repeated the Saffle and coworkers methodology for Canadian cuts of meats. Finally, in LaBudde (1992) and LaBudde and Lanier (1995) the concept was introduced of using mixture models and full-up finished product testing as a means of measuring gel strength effect from material composition and processing variables. LaBudde and Lanier (1995) also showed the high degree of correlation between the Saffle-derived ‘bind’ attribute and the gel strength measurements. With respect to internal ‘color’, generally the values measurement by Saffle and co-workers continue to be used in practice, as they are the only values systematically measured (spectrophotometric measurement of extracted hemochrome) by the same technique across a wide range of meats. In principle, the mixture model method of LaBudde and Lanier (1995) could be used to measure chroma or (L*, a*, b*) or (L*, r*, s*) (see LaBudde and Cusick, 2003) as the source of attribute levels. To date, however, no such experiment on a sufficiently wide range of ingredients to be useful in LCF has been done.

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Description

BF FRSH 50% TRIM BF FROZ 50% TRIM BF FRSH 85% TRIM BF FROZ 85% TRIM BF FRSH 90% TRIM BF FROZ 90% TRIM BF FRSH FC BULL MT BF FROZ CHEEK MT BF FROZ HEAD MT CK FRSH MSM 15% FAT CK FRSH MSM 18% FAT CK FRSH MSM 22% FAT PF FRSH 42% TRIM PK FRSH 72% TRIM PK FROZ CHEEK MT PK FRSH 95% BNLS HAM

ID

BF50 BZ50 BF85 BZ85 BF90 BZ90 BFBULL BZCHEEK BZHEAD CFMSM15 CFMSM18 CFMSM22 PF42 PF72 PZCHEEK PFHAM

B BZ B BZ B BZ B BZ BZ C C C P P PZ P

Groups 15.50 12.40 26.40 21.10 26.20 21.00 30.60 11.10 6.90 24.30 21.50 20.20 11.60 18.60 7.00 24.20

LCFBIND 25.0 25.0 42.0 42.0 42.0 42.0 48.0 48.0 29.0 21.8 19.2 18.1 9.6 15.4 29.3 20.0

LCFCOLOR 0.600 0.500 1.700 1.300 1.700 1.300 2.100 0.600 0.400 1.200 0.950 0.840 0.370 0.950 0.420 1.600

LCFWHC

5.6 5.6 8.8 8.8 8.5 8.5 10.1 9.3 6.3 3.4 2.7 2.5 3.6 3.7 6.0 4.2

LCFMEAT

0.0368 0.0368 0.0379 0.0379 0.0396 0.0396 0.0384 0.1012 0.1395 0.0540 0.0516 0.0499 0.0268 0.0336 0.1274 0.0398

Collagen (g/g)

Table 8.2 Selected nutrient contents for the sample materials of Table 8.1. ‘LCFBIND’ and ‘LCFCOLOR’ are smoothed estimates based upon Saffle and co-worker measurements

© Woodhead Publishing Limited, 2011

Description

PK FROZ HEAD MT PK FROZ HEAD MT TK FROZ MSM 20% FAT TAP WATER SOY PROTEIN ISOLATE MODIFIED CORN STARCH AUTOLYZED YEAST CORN SYRUP CORN SYRUP SOLIDS DRY CURE (PRAGUE PWD DEXTROSE SODIUM ERYTHORBATE SODIUM LACTATE SODIUM NITRITE SALT SODIUM TRIPOLYPHOS FLAVORINGS MUSTARD FLOUR SPICE

PZHEAD1 PZHEAD2 TZMSM20 WATER XISP XSTRCHCM XYEAST YCORN YCSS YCURE YDEXT YERYTH YLACTATE YNITRITE YSALT YSTPP ZFLAV ZMUST ZSPICE

Continued

ID

Table 8.2

PZ PZ TZ WN XN XN XN N N N N N N N N N N N N

Groups

7.00 2.00 15.00 2.00

100.00 80.00 30.00 6.00 7.00

5.80 4.30 18.10

LCFBIND 15.1 11.2 19.9

LCFCOLOR

0.300 10.000 0.300 2.000 0.300

4.500 7.000 1.000 0.300 0.400 0.300

0.280 0.160 0.800

LCFWHC

3.7 3.9 2.9

LCFMEAT

0.1017 0.0825 0.0532

Collagen (g/g)

Scientific modeling of blended meat products

205

Water-holding capacity (WHC) is primarily of interest in pumped muscle products or fat-reduced sausage products, where a considerable addition of free water is made. The goal is to bind the free water and prevent its separation in the package. As of the current date, the only attribute of this type known to be in use in the meat industry is the subjectively defined one supplied with the Least Cost Formulator™ software system (see the ‘LCFWHC’ attribute in Table 8.3). Table 8.3 lists estimated functional attributes for the example materials.

8.3.6 Physical attributes A number of physical properties meet the requirements of Section 8.2.1 for formulatability. These include density, heat capacity, thermal conductivity and freezing-point depression, among others. Many predictive formulae for physical properties based upon proximate analysis (moisture fat, protein, fiber, other carbohydrates, ash) are collected in Appendix A.11 of Toledo (1991). The density is actually estimated by the inverse of the ‘specific volume’ v which is calculated as the weighted average of the inverse densities of each ingredient: ρ=1/v

8.17

v = x1 / ρ1 + xn / ρn + ... + xn / ρn

8.18

where the {xi} are the weight fractions, as before, and the {ρi} are the individual ingredient densities. Alternatively, as in Toledo (1991), the formulae can be based upon the proximate analysis composition attributes. Thermal conductivity is best estimated using the volume-weighted average of the compositional attribute thermal conductivities. Heat capacity and freezing point depression are based upon mass-weighted averages. Simple averages typically suffice to estimate physical properties within several percent error. For more accurate work, the effects of incorporated air must be included for volume-weighted properties.

8.3.7 Flavor attributes At least two flavor attributes have been measured and modeled across a sufficient group of ingredients to be useful in LCF: ‘sweetness’ (relative to sucrose = 1.0) and ‘heat’ (in Scoville units). The ‘sweetness’ attribute is useful to allow automatic substitutability among sweeteners, particularly when changing them systematically, as a move from dry ingredients to liquid corn syrup. The ‘heat’ attribute might be useful for controlling pepperiness in, e.g., ‘hot Polish-style sausage’, although this is seldom done, as ‘heat’ is considered more the province of spice suppliers.

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

BF FRSH 50% TRIM BF FROZ 50% TRIM BF FRSH 85% TRIM BF FROZ 85% TRIM BF FRSH 90% TRIM BF FROZ 90% TRIM BF FRSH FC BULL MT BF FROZ CHEEK MT BF FROZ HEAD MT CK FRSH MSM 15% FAT CK FRSH MSM 18% FAT CK FRSH MSM 22% FAT PF FRSH 42% TRIM PK FRSH 72% TRIM PK FROZ CHEEK MT PK FRSH 95% BNLS HAM PK FROZ HEAD MT

Description B BZ B BZ B BZ B BZ BZ C C C P P PZ P PZ

Groups 4.8 4.8 2.1 2.1 1.8 1.8 1.5 2.4 1.9 1.8 2.1 2.4 5.3 3.0 2.2 1.2 3.2

4.3 4.3 1.3 1.3 1.0 1.0 0.7 1.7 1.1 1.2 1.6 1.9 4.9 2.4 1.5 0.5 2.6

0.1986 0.1986 0.0599 0.0599 0.0444 0.0444 0.0318 0.0776 0.0488 0.0462 0.0523 0.0623 0.1958 0.0974 0.0582 0.0177 0.1048

0.85 0.85 0.64 0.64 0.62 0.62 0.60 0.67 0.63 1.02 1.08 1.17 0.60 0.63 0.64 0.65 0.63

Calories Cal-fat Fat-sat Cholest (Cal/g) (Cal/g) (g/g) (mg/g)

Functional attributes of the sample materials of Table 8.1

BF50 BZ50 BF85 BZ85 BF90 BZ90 BFBULL BZCHEEK BZHEAD CFMSM15 CFMSM18 CFMSM22 PF42 PF72 PZCHEEK PFHAM PZHEAD1

ID

Table 8.3

0.41 0.41 0.58 0.58 0.60 0.60 0.62 0.56 0.60 8.37 8.34 8.30 0.33 0.51 0.58 0.64 0.50

1.05 1.36 1.86 0.11 0.08 0.07 0.06 0.08

0.01 0.01 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.01 0.01 0.01 0.01

Sodium Sugars Vitamin A Iron (mg/g) (g/g) (IU/g) (mg/g)

© Woodhead Publishing Limited, 2011

PK FROZ HEAD MT TK FROZ MSM 20% FAT TAP WATER SOY PROTEIN ISOLATE MODIFIED CORN STARCH AUTOLYZED YEAST CORN SYRUP CORN SYRUP SOLIDS DRY CURE (PRAGUE PWD DEXTROSE SODIUM ERYTHORBATE SODIUM LACTATE SODIUM NITRITE SALT SODIUM TRIPOLYPHOS FLAVORINGS MUSTARD FLOUR SPICE

PZ TZ WN XN XN XN N N N N N N N N N N N N 3.6 5.0 3.6

3.7

3.6 3.7 3.8 3.2 3.9

5.2 2.0

2.3

0.1 0.0

4.7 1.4

Note: Copyright © 1991 by Least Cost Formulations, Ltd., reprinted by permission.

PZHEAD2 TZMSM20 WATER XISP XSTRCHCM XYEAST YCORN YCSS YCURE YDEXT YERYTH YLACTATE YNITRITE YSALT YSTPP ZFLAV ZMUST ZSPICE 0.0146

0.0042 0.0001

0.1897 0.0531

0.61 0.95

0.05

116.00 123.10 333.20 393.40 312.50

389.60

0.50 0.09 0.15

0.34 0.48

1.0000

0.3360 0.4200

0.62

0.11

0.10

0.14 0.00 0.19

0.01 0.02

208

Processed meats

8.4 Solving the least-cost formulation–science-based formulation (LCF-SBF) problem The LCF problem to be solved is a combination of the inputs from the raw material attributes and relations, and the requirements of the product specification. The LCF process involves four major steps: problem build; problem solution; problem un-build; and sensitivity analysis. Examples of the LCF process for blended meat products can be found in Selfridge and LaBudde (1982) and LaBudde (1996). 8.4.1 Problem build The first step in building the LCF problem is identifying the variables in the problem. These are the weights of all ingredients allowed for consideration in the formula, whether or not they will have non-zero usage in the final solution. In addition, it is sometimes useful or necessary to consider explicitly ‘non-weight’ variables that are part of the problem, but do not enter into the determination of GW in eq. (8.2). These non-weight variables can be used to manipulate cost and thereby the solution to the problem. After identifying all variables in the problem, the next step is identify all of the constraints associated with the variables and the product specification. Typical constraints include upper and lower bounds on the usage of each variable, a total weight constraint, and constraints related to each product requirement. A total weight constraint is needed to define the meaning of ‘least-cost’. If GW is fixed, the solution will be the least-cost per unit GW formula. For fixed shrink loss, this is also the least-cost per unit FW formula. This is normally the ideal constraint to use, as this then minimizes the cost of product produced. In principle, however, this constraint may be replaced by some other linear functional of the material weights, such as fat (least-fat solution), or some subset of the material weights (e.g., least-cost per unit meat block weight). Each product requirement may generate zero, one or two constraints. Zero constraints are generated if the requirement cannot attain either its lower or upper limit. One constraint is generated if only the lower or upper limit is attainable, but not both, or if it is an equality constraint. Two constraints are needed when both upper and lower limits are attainable and distinct. As an example, suppose we wish to carry out a LCF for a frankfurtertype sausage with ingredient statement reading ‘Pork, Water, Beef, Sodium Lactate, ...’, and the requirements listed under ‘Limits imposed’ in Table 8.4. These requirements can be subdivided into four broad categories: 1. Proximate chemistry (fat = 28.5% FW, salt = 2.5% FW, fat + USDA-AW ≤ 39% FW, nitrite = 150 ppm MW). 2. Fixed special ingredients and flavorings (corn syrup = 2.5% GW, erythorbate = 540 ppm MW, mustard flour = 1% GW, spices = 2% GW).

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Description

A MOISTURE MOISTURE 51.6199 A FAT TOTAL FAT 28.5000 A PROTEIN TOTAL PROTEIN 10.6508 AA USDA-AW 37.5166 + FAT A SALT TOTAL SALT NaCl 2.5000 A NITRITE TOTAL NITRITE NaNO2 150.0000 M YCORN CORN SYRUP 2.5000 M YERYTH SODIUM ERYTHORBATE 540.0001 M YLACTATE SODIUM LACTATE 3.0000 M ZMUST MUSTARD FLOUR 1.0000 M ZSPICE SPICE 2.0000 A LCFBIND LCF BIND INDEX 13.0000 A LCFCOLOR LCF COLOR INDEX 13.0628 AA LCFWHC / MOISTURE 1.2046 A LCFMEAT LCF MEAT FLAVOR 3.2039 A COLLAGEN CALC COLLAGEN 2.5390 GG P 30.1339 >W GG W 0.1000 >B GM B 16.6102 > YLACTATE G Z 0.0000 20 Reqs. Shrink: 8.5000 % GW BW: 2083.63 GW: 3000.00

Type

Value Upper

Type

Activity coef.

Penalty cost High

Range Low

BIG % FW BIG −BIG −BIG 28.5000 28.5000 % FW 28.1472 −0.00027 44.7245 BIG % FW BIG −BIG −BIG 39.0000 % FW 39.0000 0.0000 −BIG 2.5000 2.5000 % FW 2.3477 −0.00125 18.9087 150.0000 150.0000 ∧ MW 4262392 −312539 2.5000 2.5000 % GW 0.00004 22.1130 2.2551 540.0000 540.0000 ∧ MW 450419936 −1125099 3.0000 3.0000 % GW 2.7224 −0.01175 10.8633 1.0000 1.0000 % GW 0.00212 58.3144 0.8874 2.0000 2.0000 % GW 1.8323 −0.00982 18.2870 13.0000 BIG FW 0.03818 17.1986 12.9671 BIG FW BIG −BIG −BIG 1.2000 BIG ABS 76.3865 6.5453 BIG FW BIG −BIG −BIG BIG % FW BIG −BIG −BIG 0.1000 BIG % GW 49.6355 25.4646 0.1000 BIG % GW 0.00084 15.1140 −3.2093 0.1000 BIG % GW 18.1670 0.1000 BIG % GW BIG −BIG −BIG FW: 2745.00 YW: 2745.00 MW: 2083.63 SW: 57.00

Lower

Limits imposed

Product formulation requirements specification and report for ‘PWBFRANK’ example product

Requirement

Table 8.4

210

Processed meats

3. Functional requirements (LCFBIND ≥ 13 FW, LCFWHC:Water ≥ 1.2). 4. Order of predominance and labeling (pork > water, water > beef, beef > sodium lactate). After identifying variables and generating constraints, a mathematical problem of the form Minimize c1 x1 + ... + cn xn

8.19

subject to: a1 1 x1 + ... + a1 n xn ≤ or = or ≥ b1 ...

8.20

am 1 x1 + ... + am n xn ≤ or = or ≥ bm where the {xj} are the (unknown) values of the n variables, and there are m total constraints, each of which is either of the ‘≤’, ‘=’ or ‘≥’ form. The {bi} are fixed (constant) values associated with the constraints, and the {aij} are fixed coefficients of the xj in the inequations. The identification of variables and the parsing of a product specification to generate constraints is typically the most difficult part of the LCF process. 8.4.2 Problem solution The LCF problem given in eqs. (8.19) and (8.20) is a standard one (‘linear programming problem’), amenable to solution by several algorithms, including the famous ‘simplex’ method (see, e.g., Dantzig, 1963). The LCF solution consists of two parts: a logical answer to the question ‘Does a feasible solution to the problem as posed mathematically exist?’ and the {xj} values which either solve the problem, or come closest to doing so. If there is no solution to the problem posed in eqs. (8.19) and (8.20), the problem is called ‘infeasible’. Generally a unique solution is found. 8.4.3 Problem un-build After solving the LCF problem, the problem build must be reversed and the solution put back into the units and references of the original product specification. In complex material management applications, this may also involve decrementing inventory by usage of materials. Reports of the LCF are then generated. Typical examples are shown in Tables 8.4, 8.5 and 8.6. 8.4.4 Sensitivity analysis Most LCF software also has the ability to generate post-solution marginal costs associated with the opportunities of increasing or decreasing material usages (‘cost to use more’ and ‘cost to use less’), and the incremental cost of a unit change in a requirement limit, if that limit is attained (‘penalty cost’).

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

FINISHED WEIGHT(FW):

GROSS WEIGHT (GW): SHRINK LOSS:

90.00 63.36 30.00 60.00

1.10

335.91 75.00 4.89

408.51 211.92 734.23

Use less

0.6998 0.2741 0.4999 0.1119 MW: 2083.63 SW: 57.00

389.56 332.91 FW: 2745.00 YW: 2745.00

0.4776

0.4370

$1311.01

BIG

BIG

BIG BIG BIG

BIG 224.9432 BIG BIG $1311.01

−BIG −8.8781 −BIG −BIG

40.1995

2.9992 −934.0558 0.9997 0.0500 0.3099 0.8998

0.5077 BIG 8.6700

0.0020 −0.0181 0.1500 −BIG 0.2999 −210.5374

0.5458

0.4551 4.3116 0.6420

Use less

$1137.25

Use more

Cost range

0.4499 −BIG 0.3799 0.3772 0.6398 0.4672

Cost LCF

0.8698 0.8571 0.9298 0.8484 1.0197 1.0156

8.5000 % GW

90.00 64.04 30.00 60.00

1.26

638.01 75.00 5.61

588.31 667.72 1373.12

Use more

Usage range

628.31 619.79 226.50

91.5000

8.5000

255.00

2745.00

100.0000

3.0000 2.1312 1.0000 2.0000

0.0375

19.7102 2.5000 0.1667

69.4544

19.6102 10.7942 39.0500

Percent of GW

3000.00

90.00 63.94 30.00 60.00

1.13

591.31 75.00 5.00

2083.63

588.31 323.83 1171.50

BF FRSH 85% TRIM BF FRSH 90% TRIM BF FRSH FC BULL MT BZCHEEK BF FROZ CHEEK MT BZHEAD BF FROZ HEAD MT 16 Materials. BW: 2083.63 GW: 3000.00

BF85 BF90 BFBULL

YLACTATE YSALT ZMUST ZSPICE

YERYTH

WATER YCORN YCURE

BF FRSH 50% TRIM PF FRSH 42% TRIM PK FRSH 72% TRIM

BF50 PF42 PF72

BLOCK WEIGHT (BW): TAP WATER CORN SYRUP DRY CURE (PRAGUE PWD SODIUM ERYTHORBATE SODIUM LACTATE SALT MUSTARD FLOUR SPICE

Description

ID

Usage

Product formulation material usage report for ‘PWBFRANK’ example product

Material name

Table 8.5

0.3879

0.4257

0.0127 0.0813 0.0041

0.0000 0.0000 0.0000 0.0000

0.0000

0.0000 0.0000 0.0000

0.0000 0.0000 0.0000

Penalty cost Upper

BIG BIG BIG BIG

0.0000 BIG

0.0000 BIG

0.0000 BIG 0.0000 BIG 0.0000 BIG

0.0000 0.0000 0.0000 0.0000

0.0000 BIG

0.0000 BIG 0.0000 BIG 0.0000 BIG

0.0000 BIG 0.0000 BIG 0.0000 BIG

Lower

% GW

% GW

% GW % GW % GW

% GW % GW % GW % GW

% GW

% GW % GW % GW

% GW % GW % GW

Type

Limits on use

212

Processed meats

Table 8.6

Sample nutritional label report for ‘PWBFRANK’ example

Nutrition Facts Serving Size xxxx (57 g) Servings Per Container xx Amount per Serving Calories 180

Total Fat 16 g Saturated Fat 6 g Trans fat 0.0 g Cholesterol 30 mg Sodium 820 mg Total Carbohydrate 2 g Dietary Fiber 0 g Sugars 1 g Protein 6 g Vitamin A 0% Calcium 0%

Calories from Fat 150 % Daily Value* 25% 31% 10% 34% 1% 0%

Amount per g 3.16174

2.56500

0.28500 0.10739 0.00000 0.52204 14.30129 0.04268 0.00000 0.00918 0.10651

Vitamin C 0% Iron 2%

0.05512 0.10479

0.00351 0.00784

Table 8.5 shows the ‘usage range’ and ‘cost range’ for the example formulation. Material BF50 (fresh beef 50% lean trim) is in the formula at 588.31 lb, based upon its current cost of $0.4499/lb. If that cost were to increase to $0.4551/lb, the usage of BF50 would drop (‘use-less’) to 106.61 lb, ceteris parabis (same limits reached). Material BF85 (fresh beef 85% lean trim) is not used in the formula, based upon its current cost of $0.8698/lb. If that cost were to drop to $0.8571/lb, BF85 would then enter the formula at 653.91 lb (‘use-more’). Table 8.4 illustrates the ‘penalty cost’ of the requirements which have their limits attained. If the 13.0 limit on LCFBIND were to be raised by +1.0 to 14.0, the cost of the formulated product would be raised by $0.03818/ lb. This ‘penalty cost’ will be valid for changes made to this limit which fall in the range (12.9671, 17.1986). When computers were slow and LCF time-consuming, sensitivity analysis was of great importance. Nowadays it is frequently simpler to just adjust assumptions and reformulate.

8.5 Advanced topics There are a number of advanced application issues that are not directly related to SBF, but which must be dealt with in practical applications of LCF as a management tool in meat processing.

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

213

8.5.1 Inventories Frequently meat processors use LCF as a material management tool in production. For this purpose (‘materials requirements planning’ or MRP), it is necessary to maintain a perpetual inventory, coordinate this inventory with that maintained by information services (IS), and include constraints to prevent materials being used beyond that allocated for use. This is generally a complex subject outside the scope of SBF, and may include issues such as lot-based formulation and chemistry and pricing subtleties (see, e.g., Selfridge and LaBudde, 1982).

8.5.2 Multiproduct formulation When determining purchasing or production plans that must incorporate constraints on the usages of scarce materials across multiple products being formulated, the optimum solution will generally be obtained only if all products are combined into a single, large-scale ‘multiproduct’ formulation problem. This multiproduct formulation problem with contain not only constraints associated with particular product requirements, but also inventory and usage requirements across all products, or ‘global’ constraints. The combined problem still has the mathematical form of eqs. (8.19) and (8.20), if variables across all products are included. For a company with many availability restrictions, multiproduct formulation typically results in a 0.5– 1.0% further cost reduction over intelligently sequenced single product formulations on reducing availabilities.

8.5.3 Multicomponent formulation Frequently it is advisable to split the physical flow in production of many meat products into two parts. The first step is a ‘preblend’, which typically consists of meat, water and salts. The second step is a ‘final blend’, where the preblend is combined with a smaller weight of meat, water, salts, spices, sweeteners and other ingredients. The purpose of the preblend is allow a 4–24 hour dwell time for the meat to swell with water and salt to increase subsequent gel strength and water-holding capacity. The time-separated two-step production complicates the phrasing and the solution of the combined product formulation problem. For more information, see LaBudde and Selfridge (1982).

8.5.4 The cost of LCF The name ‘least-cost formulation’ implies that use of LCF will always reduce cost. Although this is true in a narrow sense, it may not be true in an enterprise sense. Manufacturing operations benefit from predictability and consistency in production, and this must be taken into account as well.

© Woodhead Publishing Limited, 2011

214

Processed meats

Product blends made with fixed formulae over time will have less chemical and functional attribute consistency owing to uncontrolled variability pass-through from materials (i.e., ‘constant formulae mean varying product’). Fixed formulae thus mean increased giveaway costs and lost opportunities in purchasing, and thus are not, on the average, as economical in material cost as the LCF varying formula solutions would be. But the lower material costs of LCF comes at a cost itself: production must deal with varying formulae for blends. This requires formulation (i.e., engineering) in tandem with production scheduling, and production management is subject to continuing disturbances as formulae change. This degradation of production management results in errors to due miscommunication, misunderstandings, oversights and addition errors. These errors results in decreased production efficiency and increased rework. If the savings from LCF is less than 1% of product cost, the savings may be illusory, owing to the offsets from production inefficiency. In such a situation, the simplicity of the constant formula environment may be preferable, if the resulting finished product variation is tolerable.

8.5.5 Reverse-engineering formulae using LCF and SBF In the USA, for example, the package label disclosure provides a significant quantity of information about the composition of a meat product. The product title and qualifier shows the species and types of meats allowed in the product, and may have a standard of identity in regulations that specifies limits on moisture, fat and protein, and usages of special non-meat ingredients. For example, a product labeled ‘Beef Frank’ in the USA must only skeletal beef as the meat, must have a fat content of less than 30%, the sum of fat plus moisture minus four times protein must not exceed 40%, and there are limits on functional non-meat ingredients. The ingredient statement on the label lists the reverse order of predominance. This places strong constraints on the composition of the product. Finally, the nutritional label places additional restrictions on the relative material usages. In addition to label information, product chemistry, texture and color are measurable in many ways (including sensory panels and testing devices), particularly in comparison to a reference product formulated to known limits. Generally, with the above restrictions on the product formula, it is possible to set up an LCF specification with estimated target limits, formulation the product, and discover an equivalent formula. This process of using LCF for reverse engineering a meat is typically successful in finding a formula that can be used for copying a competitive product in the marketplace. Production of a test batch of two, with subsequent tweaking of formulation limits is usually all that is needed to provide a relatively indistinguishable result. This process of reverse-engineering competitor’s products is a common activity in facilities that bid for contracts to ‘co-pack’ branded products of other companies.

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

215

8.6 Conclusions LCF and SBF models supplied by software vendors have been in widespread and continuous use for nearly 50 years across the meat industry in North America and, to a lesser extent, throughout the world. The models for ‘bind’ and ‘color’ developed by Saffle and coworkers have been validated by vast numbers of production batches. However, despite this pervasive use, the SBF element remains immature and undeveloped. Other than the pioneering work of Saffle and associates in the 1960s, and the presentation by LaBudde and Lanier of the finished product testing of mixture models in the 1990s, little of practical value was done by meat scientists and technologists to improve science-based models of blended meat product properties. The primary reason for this lack of progress is the conspicuous lack of funding available for this type of research, either from government or from industry. Research in the meat industry is driven by regulatory changes (funded by the industry associations) and new function ingredients (funded by ingredient suppliers). A secondary reason why new research is scarce is the difficulty of the studies needed to develop science-based models suitable for use in LCF. Firstly, a large range of meats and ingredients must be included, so that practical formulations can be accomplished. Secondly, meat lots are highly variable, so multiple replications of the experiments are required. Finally, small-scale pilot operations found in university environments have variable product output, sensitive to personnel, equipment and operating conditions. For best results, SBF models should be developed in a controlled, largescale operating process, so that product batch-to-batch uniformity is maximized. The best approach to moving science-based models for formulation forward is to embed academic researchers in a long-term cooperation with a large-scale, well-controlled processing plant. Over a substantial period of time, multiple lots and a wide range of materials can be consistently tested in varying formulae under controlled conditions. Ideally the experiment should involve replication in at least two different plants to provide the most general results. This would obviously require long-term interest on the part of researchers, a substantial budget, and a willingness on the part of plant management to allow outsiders into their process.

8.7 References anderson, hv and clifton, es. (1967). How the small plant can profitably use leastcost sausage formulation. Meat Processing 2: 17. anon. (1970). Linear programming – meat blending. IBM Corporation. carpenter, ja and saffle, rl. (1964). A simple method of estimating the emulsifying capacity of various sausage meats. J Food Sci 29: 774–781.

© Woodhead Publishing Limited, 2011

216

Processed meats

charnes, a and cooper, w. (1961). Management Models and Industrial Applications of Linear Programming. Volumes I and II. Wiley, NY. comer, fw and dempster, s. (1981). Functionality of fillers and meat ingredients in comminuted meat products. Can Inst Food Sci Tech J 14: 295–303. cornell, j. (2002). Experiments with Mixtures: Designs, Models, and the Analysis of Mixture Data, 3rd ed. Wiley-Interscience, NY. danø, s. (1974). Linear Programming in Industry, 4th ed. Springer-Verlag, NY. dantzig, gb. (1963). Linear Programming and Extensions. Princeton Univ. Press, Princeton, NJ. gordon, a and barbut, s. (1992). Mechanisms of meat batter stabilization: a review. Crit Rev Food Sci & Nutr 32(4): 299–332. hsu, c-k, kolbe e and english, m. (1996). A nonlinear programming technique to develop least cost formulations of surimi products. J Food Proc Eng 20(3): 179–196. labudde, ra. (1991). LaBudde’s Ready Reference. Least Cost Formulations, Ltd., Virginia Beach, VA. labudde, ra. (1992, revised 2006). Review of comminuted and cooked meat product properties from a sol, gel and polymer viewpoint. TR059. Least Cost Formulations, Ltd., Virginia Beach, VA. Available on-line at: http://www.lcfltd.com/downloads/TR059%20review%20properties%20sol%20gel%20polymer.pdf. labudde, ra. (1996). Scientific formulation of low-fat meat products. TR107, Least Cost Formulations, Ltd, Virginia Beach, VA. Available on-line at: http://www. lcfltd.com/downloads/Tr107%20scientific%20formulation%20of%20low-fat%20 meat%20prods.pdf. labudde, ra and cusick, rs. (2003). Color trajectories as visual indication of spoilage in fresh meats. American Meat Science Association, Proc. 56th Annual Reciprocal Meats Conference. Also available as TR195 from Least Cost Formulations, Ltd, Virginia Beach, VA. Available on-line at: http://www.lcfltd.com/downloads/ tr195%20color%20trajectories%20as%20visual%20indication%20of%20 spoilage.pdf. labudde, ra and lanier, tc. (1995). Protein functionality and development of bind values. Amer Meat Sci Assn Recip Meat Conf Proc 48: 59–68. labudde, ra and selfridge, gs. (1982). Preblending. In Romans, JR. et al. (1994). The Meat We Eat, 13th ed. pp. 869–882. Interstate Publishers, Danville, IL. lanier, tc. (1985). Fish proteins in processed meat. Amer Meat Sci Assn Recip Meat Conf Proc 38: 129. lanier, tc and labudde, ra. (1993). Gelation approach to determining bind values for least cost formulation: Phase II studies. Final report to National Live Stock and Meat Board, Chicago, IL. lanier, tc, labudde, ra and carpenter, ja. (1993). Gelation approach to determining bind values for least cost formulation. Final report to National Live Stock and Meat Board, Chicago, IL. pearson, am and tauber, fw. (1984). Processed Meats, 2nd ed. AVI Publishing, Westport, CT. porteous, jd. (1979). Some physico-chemical ‘constants’ of various meats for optimum sausage formulation. Can J Food Sci Technol 12(3): 145–148. pouttu, p and puolanne, e. (2003). A procedure to determine the water-binding capacity of meat trimmings for cooked sausage formulation. Meat Sci 66(2): 329–334. regenstein, jm. (1988). Meat batters: why it is not an emulsion. Amer Meat Sci Assn Recip Meat Conf Proc 41: 40. regenstein, jm. (1989). Are comminuted meat products emulsions or a gel matrix? In Food Proteins, Kinsella, KE and Soucie, WG eds. Amer Oil Chem Soc, Champaign, IL pp. 178–194.

© Woodhead Publishing Limited, 2011

Scientific modeling of blended meat products

217

saffle, rl. (1968). Meat emulsions. Adv Food Res 165: 105–160. saffle, rl, christian, ja, carpenter, ja and zirkle, sb. (1967). Rapid method to determine stability of sausage emulsions and effects of processing temperatures and humidites. Food Tech 21: 100–104. selfridge, gc and labudde, ra. (1982). Least cost formulation. In Romans, JR. et al. (1994). The Meat We Eat, 13th ed. pp. 844–869. Interstate Publishers, Danville, IL. stigler, gj. (1945). The cost of subsistence. J Farm Econ 27(2): 303–314. swift, ce. (1965). The emulsifying properties of meat emulsions. Proc Meat Industry Res Conf, Amer Meat Sci Assn, pp. 78–93. swift, ce. et al. (1961). Comminuted meat emulsions. The capacity of meats for emulsifying fat. Food Technol 15(11): 468. toledo, rt. (1991). Fundamentals of Food Process Engineering, 2nd ed. Van Nostrand Reinhold, NY.

© Woodhead Publishing Limited, 2011

9 Blood by-products as ingredients in processed meat D. Parés, E. Saguer and C. Carretero, University of Girona, Spain

Abstract: Blood from slaughtered animals is a natural by-product of the meat industry that has the potential to generate a range of food ingredients, especially suitable for meat products. Well-defined nutritional and functional ingredients which have special uses, such as emulsifying and texturising agents, colourants and/or bioactive products, may be derived from neat blood. The challenge for the industry lies in the ability to make the necessary technical improvements to the bleeding/sticking stations in slaughterhouses and to the recovery of the blood itself, and its ability to reach the point that it can be exploited economically. The use of blood, as it is after collection or conveniently processed to produce intermediate food products, is discussed in this chapter. Key words: blood, red blood cells and plasma proteins, functional properties, bioactive peptides, meat ingredients.

9.1 Introduction: blood characterisation, recovery and processing 9.1.1 Driving forces for utilisation of blood Blood from slaughtered animals is a common by-product of the meat industry, which is obtained in large volumes especially in industrial slaughterhouses. While half of the blood volume of a slaughtered animal remains in the edible tissues such as meat and internal organs, the other half can be recovered via exsanguination. An approximation of the amount of potential blood that can be derived from primary meat processing operations in Europe can be estimated from the number of slaughtered animals; which in 2007 were in excess of 295 and 47 million pigs and cattle, respectively (FAOSTAT, 2007). If we consider that 3 litres of blood can be collected from each pig and over 10 litres from each beef, the annual available blood supply can exceed 1,355,000 tonnes. Taking into account average protein

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

219

content around 18%, this volume of blood is equivalent to near 244,000 tonnes of protein, which represents 5–8% of the protein yield of slaughtered animals. As explained in this chapter, interesting industrial applications of blood proteins in meat products derived from both their nutritional value and functional properties have been widely studied and described. Unfortunately, the interest in making use of this major potential protein resource is still rather limited and all too often blood is considered as a waste product. In such cases, the disposal of blood to fulfil the current regulations of the water drained to the sewer system from livestock slaughtering facilities requires not only expensive decontamination treatments but also large amounts of water. The decontamination treatments can be eluded, and hence the costs of disposal reduced, if the collection of blood is carried out together with other by-products and all the organic materials are unspecifically treated in large digesters, but the end product does not have a remarkable added value and the possibility of valorisation remains unexploited. In the future, we cannot afford to waste such large amounts of valuable animal protein. Food, and especially meat processing, offers a suitable way to integrate whole blood or separated blood fractions into human diets.

9.1.2 Physical and chemical properties of blood and its fractions Blood is composed of blood cells, which correspond to 40–45% of blood weight, suspended in a liquid called blood plasma, which represents up to 60% of the total fraction. The cellular elements present in blood are mainly red blood cells (RBC or erythrocytes), together with a minority content of white corpuscles (leucocytes) and platelets. RBC and plasma are slightly alkaline pH (7.3–7.5) and can be easily separated by centrifuging. Within the RBC fraction, total protein content ranges from 28 to 38%, and haemoglobin (Hb) is the major protein constituent. The Hb molecule is an assembly of four globular protein subunits. Each subunit is composed of a protein chain with molecular weight of about 17 kDa tightly associated with a non-protein haem group. Haemoglobin shows a red colour heavily dependent on the oxygenation/ oxidation state of the haem iron. Deoxyhaemoglobin, the deliganded ferrous Hb, is purple red, while oxyhaemoglobin, the dioxygen ferrous form, has a bright red colour. The isoelectric point (pI) is 6.7 and 6.9 in deoxy and oxyhaemoglobin, respectively. Methaemoglobin is the oxidised form of Hb, with the iron in the Fe3+ state, and has brown coloration. Plasma is a straw yellow liquid with 6–8% of total protein content. It contains a complex mixture of proteins, which can be classified into three major groups, namely albumin (up to 60%), globulins (40%) and fibrinogen (around 3%). Albumin is a globular protein with a molecular weight of 69 kDa and a pI of 4.8. Globulins are an heterogeneous group of globular proteins mainly

© Woodhead Publishing Limited, 2011

220

Processed meats

containing α, β and γ globulins, with a wide range of molecular weights, from a few to hundreds of kDa, and pI between 5 and 7. Fibrinogen is a clotting protein with fibrous structure of 340 kDa made by three pairs of nonidentical polypeptide chains forming two identical subunits. When fibrinogen is removed from plasma, the remaining fraction is named serum (Putnam, 1975). Blood has several potential applications. For the food industry, incorporation of blood or some blood derivatives into foodstuff is derived from its nutritional value and good functional properties, including its potential role as a colouring agent. Blood has good nutritive value thanks not only to its high protein content but also because of its high efficacy index, which is even larger than casein (Young et al., 1973). However, the amino acidic profile is not considered well balanced owing to the deficit in the essential amino acids isoleucine and methionine. On the other hand, blood has high iron content bound to Hb, the best form of iron in terms of bioavailability (Reizenstein, 1980). Haem iron is more readily absorbed than the inorganic form found in plants or the ferrous salts commonly used in food fortification (In et al., 2002). Blood proteins can also be useful functional ingredients in the formulation of food products since they have gelling, emulsifying, foaming and/or water-binding properties. Although in some European countries, such as France, the addition of blood fractions to meat products is seen as a positive on labels, the use of animal blood as a food additive may not be accepted overall; in some cases attending to religious considerations. However, taking into account that blood proteins are naturally found in meat, its use in meat products should not actually be considered anything but the addition of a natural ingredient. Moreover, it is worth pointing out that blood proteins do not show allergenic potential; hence they may become an alternative to the functional ingredients widely used in foods, such as wheat, soya, egg or dairy proteins, responsible for the most common food allergies.

9.1.3 Recovery of blood from slaughterhouses For blood to be used in foods it is necessary to guarantee that it comes only from veterinary-approved animals that have been passed as free from disease, etc. During the last few years, the legal framework for the use of blood has been determined by animal health issues. As a consequence of the emergence of transmissible spongiform encephalopathy as a public health issue in the 1980s and 1990s, utilisation of animal by-products in Europe is now legislated under two guidelines: namely, Council Directive 77/99/EC and Regulation (EC) No. 1774/2002. For non-ruminant animals, only blood from animals that passes both ante and post mortem inspections can be processed to produce haemoderivatives, products which are able to be used for animal feed as well as for human, medical or nutritional consumption.

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

221

The level of hygiene employed while collecting blood during slaughtering is another critical issue for blood utilisation fit for human consumption. The microbiological quality of blood is a critical control point in monitoring and control, either to guarantee the safety for the consumer in terms of health considerations or to prevent the spoilage of blood products and foods which contain them. Initially, blood is sterile in live healthy animals; thus, most of the contaminating microbiota is incorporated during the bleeding practice. The undesirable presence of microorganisms can be controlled by means of an appropriate and well-designed collecting system. Actually, one of the main reasons for underutilisation lies in the lack of suitable facilities to effectively collect and handle blood in the slaughterhouse. Blood can be collected in open-draining systems, where no specific precautions are taken to guarantee the absence of foreign bodies and/or low bacterial counts. Animals are usually slaughtered through sticking and blood drains downwards thanks to gravity, thus contacting with the carcass and potentially sweeping surface microorganisms. Strange materials, such as washing waters, and other organic materials can mix with blood in the blood collecting vessel/sticking station, resulting is a low grade bloodstream. On the other hand, hygienic blood collection can be achieved by using closed-draining systems. In this case, blood is collected with a hollow sticking knife through vacuum piping directly from the wound in the throat of the slaughtered animals and directed to refrigerated storage vessels, thus reducing the potential contact with the skin of the animal and exposure to environmental contaminants. The drawbacks of this system are the large capital investment required for its construction and implementation and the resulting slowing of the slaughtering line speed, especially in the case of pig slaughtering operation. As alternative to the use of a hollow knife, a well-designed slaughtering system combining an open-drainage with physical barriers to undesirable contamination may permit the hygienic collection of blood. Blood from the drainpipe is immediately pumped to heat-exchangers to lower the temperature to 3 °C or below before final collection in storage tanks. In order to preserve blood quality and extend its shelf-life, the addition of a proper anticoagulation agent to prevent blood clotting has been introduced. The design of the piping system to minimise the haemolysis of blood when pumped to the storage tanks through the cooler system, and the size and temperature of the tanks to control the sedimentation of solids and the microbial growth are important considerations (Carretero and Parés, 2000). Blood, owing to its overall composition together with its high water content and pH value, is highly perishable. Moreover, the development of spoilage microorganisms provokes severe damage to blood functionality. Besides the initial microbial counts, storage time and temperature control (until required for further processing) turn out to be two key features to keep it with an acceptable microbiological quality (Carretero and Parés, 2000).

© Woodhead Publishing Limited, 2011

222

Processed meats

9.1.4 Processing of blood to prevent microbial spoilage Blood to be processed requires rapid handling because refrigeration itself does not guarantee its stability long term. The storage of blood at refrigeration temperatures exerts a selective pressure that merely redirects microbial growth towards the development of psychrotrophic bacteria. The dominating group within psychrotrophs is Pseudomonas (Erikson and Von Bockelmann, 1975), which has important damaging abilities, especially concerning proteins. In addition, the lack of microbial lethal treatments during the manufacturing processes used to obtain blood-derived protein powders, which typically include concentration (ultrafiltration or evaporation at low pressure) and dehydration (spray-drying) steps, do not significantly reduce the bacterial counts (Parés et al., 1998a; Dailloux et al., 2002; Toldrà et al., 2002). The presence and potential activity of the contaminating bacteria can jeopardise consumers’ health as well as the ultimate nutritional and functional properties of the protein powders. While conventional thermal treatment effectively controls microorganisms, heating also leads to the physical unfolding and structural modifications in the blood proteins that induce an irreversible decrease or loss of some key functional properties. It is possible to obtain high quality and microbiologically stable blood derivatives to be used as functional ingredients for foodstuff, by combining biopreservation and high hydrostatic pressure (HHP). HHP itself has shown promise as a non-thermal sanitising technology to reduce the microbial contamination of RBC and plasma with minimal effects on the functionality of their proteins (Parés et al., 2000, 2001; Toldrà et al., 2002, 2004). Yet, since HHP treatment would not be carried out immediately after the collection of blood, it is useful to start with a system to control the growth of undesirable bacteria until further processing is performed. The inoculation of lactic acid bacteria (LAB) just after the collection of blood could reduce microbial hazards without the need of changing the slaughterhouse facilities; hence, providing a simple and low-cost solution for the processing industry together with a safer and better quality product for the consumers (Parés et al., 2004). LAB inoculation concurrently with the enrichment with a selective energy source – that is, inulin – has been proposed as an effective way to control or reduce the growth of undesirable bacteria and to prevent, at the very least, spoilage processes in the case of a cold-chain breakdown (Dàvila et al., 2006). In addition, the use of complementary techniques, such as HPP processing of plasma and RBC fraction from biopreserved blood, proved to be helpful thanks to synergistic effects via the hurdle concept and the reduction or elimination of the inoculated LAB strain (Saguer et al., 2007a; Toldrà et al., 2008). It has been reported that the presence of the LAB strain (Enterococcus raffinosus-PS99) during a 3 day storage of blood at 5 °C, followed by a HHP treatment (15 min, 20 °C, at 400 or 450 MPa for RBC and plasma, respectively) can lead to blood products with improved microbial quality and

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

223

better safety guarantees. Since not only microbial growth but also the potential loss of functionality may be prevented, the proposed method could be seen as a new approach to process and preserve animal blood fractions for the development of functional and/or nutritional food ingredients with added value (Dàvila et al., 2006).

9.2

Applications of blood in processed meat products

9.2.1 Techno-functional ingredients The chance of obtaining marketable products from animal blood is interesting because of the techno-functional properties of its proteins, which are comparable to egg albumin or whey proteins (Crenwelge et al., 1974; Cheftel et al., 1989). Whole blood and its derivatives have long been used as nonmeat protein (NMP) ingredients in processed meat products to improve their technological and sensorial quality thanks to the water and fat-binding properties of blood proteins, which affect the physical behaviour of food from processing to consumption. As mentioned above, blood proteins can be considered competitive food ingredients because of the large quantities generated daily and because they are not regarded as strange ingredients in formulated meat products: residual blood is a natural component of meat, with no allergenic problems associated to its consumption. Whole blood, mostly from cattle and pigs, has been used for centuries in making meat products in a variety of countries all over the world, each one with its own unique recipe. In Europe, countless different blood-containing meat products are produced, such as the blood sausage Blutwurst in Germany, the black pudding in the United Kingdom, and many other regional variants in France, Spain, Portugal, Italy, Belgium, the Netherlands, Iceland, Sweden, Finland and throughout Eastern Europe. While blood is the most characteristic component within these speciality products, different animal – particularly fat and/or meat – or plant products are added as additional ingredients or fillers, depending on regional variant. Nowadays, changes in the traditional formulation of blood-based products in order to increase their sensorial and nutritive quality are being proposed (Choi et al., 2009). Apart from this application, using whole blood in food industry has so far been limited owing to aesthetic- and flavour-related aspects because of the undesirable dark brown colour and unpleasant metallic flavour of Hb. Therefore, to avoid the darkening/flavouring handicaps and/or to take advantage of the techno-functional properties of specific blood proteins, RBC and plasma are frequently separated. Both fractions can be used as obtained after centrifugation, but more often they are frozen or spray-dried. 9.2.2 RBC and its derivatives Haemolysis of RBC – by means of ultrasound or homogenisation – followed by an optional centrifugation step to remove cell debris is the usual

© Woodhead Publishing Limited, 2011

224

Processed meats

procedure to liberate Hb from the erythrocytes (Toldrà 2002; Salvador et al., 2009a). Fresh Hb is highly soluble, a prerequisite for protein applications in food industry. However, it shows poor interfacial properties, which are only slightly improved after spray-drying, especially foaming (Álvarez et al., 2009; Salvador et al., 2010). Furthermore, Hb is not able to form gels at room temperature and a high protein concentration (∼15% w/v) is needed to get a solid-like product after heating which looks like more a paste than a real gel (Toldrà, 2002; Àlvarez et al., 2009; Salvador et al., 2009b). High hydrostatic pressure does not improve Hb functional properties, even when pressures lower than 400 MPa are used in order to avoid pressure-induced gelation (Toldrà et al., 2004). To our knowledge, there is currently no literature on the application of other physical technologies to modify Hb functionality. Besides its poor techno-functionality, the above-mentioned handicaps for the use of whole blood as a food ingredient are also limiting factors for the RBC utilisation. On the other hand, Hb can act as a powerful catalyst of lipid oxidation at relatively low concentrations while the opposite effect has been observed at higher concentrations (Johns et al., 1989; Ockerman and Hansen, 2000) but with the pro-oxidative/inhibitory behaviour also being dependent on lipid : haem ratio (Kendrick and Watts, 1969; Johns et al., 1989; Chan et al., 1997). The pro-oxidative effect could limit the shelf-life of food products, but this problem is minimised in meat products utilising mostly animal saturated fat within their formulations. Globin Hb valorisation can be improved by removing the haem group – responsible for red/brown colour – from globin, the remaining apoprotein. Haemic Fe can be used for fortification of food, while colourless isolated globin has been shown to have some useful functional properties, such as solubility, foaming and emulsifying properties, as well as enhanced swelling and waterholding capacity (Tybor et al., 1973, 1975; Ranken, 1980; Nakamura et al., 1984; Wismer-Pedersen, 1988; Damodaran, 1997; Silva et al., 2003). As a whole, globin has been shown as positively influencing the texture of several processed meat products when replacing meat and soy proteins, which are commonly used as binders to stabilise emulsions and reduce water loss (Auvinen, 1992; Jelenikova and Pipek, 2006). Similarly, globin has been proposed as a potential fat replacer to develop healthier meat products (Jiménez-Colmenero, 1996; Viana et al., 2005). However, it is important to highlight that the functional properties of isolated globin are strongly dependent on the bleaching method used – i.e., oxidation with hydrogen peroxide or ozone; haem extraction using acidified organic solvents, particularly cold acetone; and absorption on carboxymethyl-cellulose (CMC), active carbon or sodium pectate (Antonini and Brunori, 1971; Marc and Vancikova, 1978; Oord and Wesdorp, 1979; Sato et al., 1981; WismerPedersen, 1988; Rwan and Chang, 1996; Silva el., 2003, among others).

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

225

By way of examples, H2O2-decoloured globin has low solubility as well as poor emulsifying and gelling properties at an acidic pH, i.e. close to those typically found in meat products and a reduced nutritional value (Álvarez et al., 2009). In contrast, decolourised globin obtained by the acidified acetone method shows good emulsifying properties (Schaper Bizzotto et al., 2005) and that obtained through CMC-precipitation is able to form heatinduced gels (Tybor et al., 1975; Auvinen, 1992). Unfortunately, the last two procedures are expensive and therefore their commercial success limited. A process by combining an efficient cleavage of the haem moiety using a strong inorganic acid, followed by precipitation and a subsequent oxidation of the residual haem using a low quantity of an oxidising agent has been described; this way the negative effects of the oxidant agents being considerably reduced (Wismer-Pedersen, 1989). Globin hydrolysates Globin functionality can be improved through its chemical or enzymatic hydrolysis. Hydrolysates obtained from acidified acetone decolourisedglobin after its treatment with citric acid show higher solubility and better heat-induced gelation properties than intact globin (Liu et al., 1994a, 1994b). Partial hydrolysis of globin can also be carried out using specific proteases, with the results depending on the peptide sizes obtained; 20 amino acids have been reported as the minimum size for peptides showing improved functional properties (Brekke and Smith, 1985). According to Schaper Bizzotto et al. (2005), the tryptic hydrolysis enhanced the emulsifying properties of acidified acetone decolourised-globin in a pH range including that own of meat products. At any case, hydrolysis degree must be controlled to take advantage of this process (Brekke and Smith, 1985; Liu et al., 1996). However, protein hydrolysates can cause flavour problems when added to food products due to the bitterness of oligopeptides containing hydrophobic amino acid residues. Chemical and enzymatic hydrolysis of intact Hb has also been extensively assayed as a discoloration method. Acid hydrolysis using strong inorganic acids can actually be effective but it leads to hydrolysates with reduced solubility and poor biological value (Fretheim et al., 1979; Wismer-Pedersen, 1980). Several enzymatic treatments using alcalase, pepsin, papain or tripsin, in single or multi-step reactions, have been reported (Sephton and Clegg, 1993; Synowiecki et al., 1996; Aubes-Dufau and Combes, 1997; Schaper Bizzotto et al., 2005). According to Toldrà (2002), the enzymatic Hb hydrolysates show poor functionality, and, in general, the complete colour removing requires a subsequent separation by centrifugation or ultra-filtration or, alternatively, by absorption on active carbon, diatomaceous earth or aluminium oxide (Piot et al., 1986; Wismer-Pedersen, 1988). Hb as a natural red colourant Hb could also be used to enhance the red colour in some formulated meat products; i.e. products containing high levels of extenders or fillers of plant

© Woodhead Publishing Limited, 2011

226

Processed meats

origin or products manufactured using pale soft exudative (PSE) meat. Also, the still current controversy around carcinogenic nitrosamines in cured meat products is pushing for a reduction in the authorised levels of nitrates and nitrites, making the addition of colouring agents necessary. Since 1970, when both embryotoxicity and carcinogenic effects were reported for amaranth (Boffey, 1976; Shtenberg and Gavrilenko, 1970; Golz et al., 1991), synthetic red colouring agents in foods have had poor acceptance, resulting in a growing interest in developing safe alternatives. Permitted anthocyanins, carotenoids and betanins from fruits and vegetables as well as cochineal and carmine obtained from the dried bodies of the mated female insect Dactylopius coccus can be used for such purpose (Duhard et al., 1997). However, the use of Hb as a natural colorant would represent a feasible alternative, provided that the stabilisation of the red colour is achieved. Thus, stabilising the haem-iron in the reduced state to minimise its oxidation susceptibility during blood processing and storage is essential. Different approaches to destabilizing action of oxygen, high temperatures and light have been considered in the last decades (Saguer et al., 2003; Salvador et al., 2009a). Treating Hb with NaNO2 in the presence of sodium ascorbate results in a highly nitrosated haem pigment (nitrosoHb) which can be used as a colorant in meat products with no pro-oxidative effects and with practically no residual nitrite content (Sakata et al., 1992). An appropriate concentration of NaNO2 should be used along with a high glucose concentration, a reducing agent able to stabilise protein structure and increase the water retention capacity – so making more difficult the access of oxidant agents to haemic iron (Sakata et al., 1993). More recently, glucose in combination with chelating agents such as nicotinic acid or its amide has been suggested as a feasible choice to protect Hb from oxidation during dehydration and subsequent storage (Saguer et al., 2003; Salvador et al., 2009a). However, further research must still be carried out in order to guarantee the haem pigment stability through the usual processing and storage conditions of foodstuffs.

9.2.3 Plasma and its derivatives To date, some research has been conducted to study the functionality of plasma (Tybor et al., 1975; Swingler et al., 1978; De Vuono et al., 1979; Howell and Lawrie, 1984a, 1984b; King et al., 1989; O’Riordan et al., 1989; Raëker and Johnson, 1995; Oshodi and Ojokan, 1997; Parés et al. 1998a, 1998b, 2000; Duarte et al., 1999; Parés and Ledward, 2001; Ramos-Clamont et al., 2003; Silva and Silvestre, 2003). Plasma proteins show interesting functional properties that include good solubility over the whole pH range, forming and stabilising foams and emulsions thanks to their ability to form interfacial films, as well as the ability to form heat-induced gels with good textural properties and high-water holding capacity. Emulsifying and gelling properties are the most interesting functional properties of plasma when used in

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

227

formulated meat products. Plasma can be used in meat products in higher quantities than RBC or its derivatives, including those decolourised (Guzman et al., 1995). Plasma can be added up to levels able to stabilise the water/protein/fat matrix in a large variety of comminuted meat products such as frankfurters, wursts, bologna sausages, mortadella and salami (Sanina, 1971; Cironeanu et al., 1973; Savostin, 1977; Breer, 1978; Rogov et al., 1981; Nakamura et al., 1983; Song et al., 1984; Dolatowski, 1985, 1986; Georgakis et al., 1986; Jelenikova and Pipek, 2006). The presence of plasma in such products has a significant influence in their texture, especially in the case of those consumed after cooking because of the gel-forming ability of plasma proteins (Cofrades et al., 2000; Jelenikova and Pipek, 2006; Pietrasik et al., 2007). Its higher textural characteristics makes it possible to replace soy proteins by plasma in comminuted meat systems (Pietrasik et al., 2005). Plasma is also used in injected and brine-added hams thanks to its high solubility and low viscosity (Feiner, 2006) and improved sensorial attributes have been reported in fermented meat products containing it (López et al., 1992). Its use as a fat substitute in meat products without negative effects on their quality has also been suggested (Cofrades et al., 2000; Viana et al., 2005). On the other hand, plasma is able to form edible films, which can be used as meat product casings (Nuthong et al., 2009). With regard to plasma functionality, it is important to draw attention to the fact that its emulsifying and heat-induced gelling properties are very sensitive to pH and can be reduced or even lost as pH drops from physiological to acid conditions, i.e. closer to those of meat fermented products (Parés et al., 1998a; Parés and Ledward, 2001; Saguer et al., 2008). Parés and Ledward (2001) investigated the functionality of blood plasma samples adjusted to pH 5.5, 6.5 and 7.5 and treated by HHP from 300 to 600 MPa. Improvements to the emulsifying activity and stability were observed only in plasma at pH ≥ 6.5 treated at 400 MPa; however, none of the HHP treatments led to better emulsifying properties of acidic plasma. Moreover, pressure treatments such high as 600 MPa were necessary to get significantly harder gels from solutions at pH 5.5. Recent works consisting of the treatment of plasma solutions with microbial transglutaminase have resulted in an improved ability to form heat-induced gels at pH acid, especially significant when combined with HHP treatments up to 400 MPa (Saguer et al., 2007b; Fort et al., 2008) and after the cold storage of the treated product (Fort et al., 2009). It is worth remarking that this combined treatment makes it possible to enhance textural properties but not the water retention capacity, probably because the cross-linking activity is not higher enough to affect the gel microstructure. Plasma protein fractions As described above, plasma is a complex blend of proteins. This mixture contains globular and fibrous proteins, sized few to hundred kDa, highly or poorly cross-linked, with high or low hydrophobicity. From the different

© Woodhead Publishing Limited, 2011

228

Processed meats

physico-chemical and functional characteristics of the plasma proteins, a wide range of functional ingredients can be developed through fractionation and reformulation of the natural occurring protein profile aiming at enhance specific properties (Satterlee, 1975; De Vuono et al., 1979; SabljakUglesic and Prilika, 1979; Torres et al., 2002; Dàvila et al., 2007a, 2007b, 2007c). Several methods have been used for plasma protein fractional precipitation and purification, which include the salting out, alcohol fractionation, aqueous two-phase fractionation, hydrophobic interaction chromatography and ion exchange chromatography (Cohn et al., 1946; Rito-Palomares et al., 1998; Moure et al., 2003; Ramos-Clamont et al., 2003; Burnouf, 2007; Dàvila et al., 2007b). To obtain beneficial effects after protein separation depends not only on the fractionation method used but also on the blood source and the measured property (Ramos-Clamont et al., 2003). The knowledge of the functional behaviour of the main plasma proteins separately is useful in the engineering of a plasma derivative product designed for specific food requirements, by reformulating its natural composition and modifying the particular processing conditions, specifically related to protein concentration, pH and temperature. According to this, fibrinogen/thrombin mixtures or plasma with increased fibrinogen content have been suggested as cold-set binding agents in meat products (Herrero et al., 2007, 2009). These ingredients are able to enhance texture and are especially useful for products with reduced salt or polyphosphates. For fibrinogen/thrombin mixture, the blood clotting action together with plasma transglutaminase causing the fibrin cross-linking, could be the binding mechanism conducing to cold-set gel formation (Wijngaards and Paardekooper, 1987; Boles and Shand, 1998). According to Dàvila et al. (2007b) and Álvarez et al. (2009), although the gelation temperature has been observed around 71 °C for whole plasma, the gelation temperature for the different plasma proteins ranges from 45 to 68 °C, with the lowest temperature corresponding to the fraction containing α- and β-globulins while the highest value being observed for albumin; fibrinogen and γ-globulins form gels at intermediate temperatures (∼57 °C). Also, the protein concentration needed to get a gel is so much lower for individual plasma fractions (particularly for globulins) than for whole plasma, indicating an antagonistic interaction between some of its proteins (Álvarez et al., 2009). On the other hand, the foaming capacity of plasma is as good as the commonly used egg white, but this is true as long as albumin is the dominant fraction – at least at pH higher than 4.5 – because globulins showed poor foaming capacity. Plasma and albumin were good foam stabilisers at pH 6.0. In relation to the emulsifying properties, all fractions had good activity indexes, but isolated albumin and globulins, each on its own, developed emulsions much more stable than other fractions at pH 7.5. At acidic conditions, removing fibrinogen has been proposed for the best emulsifying properties (Dàvila et al., 2007c).

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

229

Nowadays, a plasma protein powder developed by the Dutch firm Harimex, which is intended for use as a cold binding agent for meat and fish muscle tissues as an additive for reconstituting food, is already being commercialised in the USA and several European countries, under the brand name Fibrimex®. It is an enzyme preparation which consists of thrombin and fibrinogen, both of which are obtained from blood plasma. When applied to meat, the thrombin transforms fibrinogen to fibrin, which enables the binding of meat pieces in order to produce a single meat product. The preparation can be used to upgrade raw materials by binding together small pieces of meat into standardised new size products. With respect to the use of this enzyme preparation, the EFSA Scientific Panel on food additives, flavourings, processing aids and materials in contact with food, concluded in its opinion on 26 April 2005 that it raised no safety concerns. Although it does not yet have the approval of the European Parliament, there is a draft of the European Commission suggesting that one entry related to ‘Bovine and/or porcine thrombin to be used together with fibrinogen’ should be inserted in annex IV of the Directive 95/2/EC on food additives other than colours and sweeteners.

9.2.4 Bioactive ingredients Many dietary proteins are an important source of biologically active peptides, which are produced during protein hydrolysis and can be used as ingredients of functional or health-promoting foods (Korhonen and Pihlanto, 2003; Hartmann and Meisel, 2007; Erdmann et al., 2008; Korhonen, 2009). To date, antihypertensive, antithrombotic, immunomodulatory, antimicrobial and antioxidant activities are specific physiological properties that have been described in a range of protein hydrolysates. The activity of these peptides is based on their inherent amino acid composition and sequence, but they are inactive within the sequence of their original protein and must be released by enzymatic hydrolysis either during gastrointestinal digestion or during food processing (Erdmann et al., 2008). The size of the active sequences may vary from 2 to 20 amino acid residues, and many peptides have revealed multifunctional properties (Hartmann and Meisel, 2007). Although most of these physiologically active peptides are derived from milk and eggs, they are also found in meat and plants. Since the major component of blood is protein, with a mean concentration of 18%, conveniently treated it could be an excellent source of bioactive molecules. So, blood-derived peptides may be used as bioactive compounds enabling the development as novel functional meat products. Blood as a source of bioactive peptides and other healthy components A new field of study, focused in obtaining bioactive peptides from blood, has been intensively developed for the past few years. Different isolated or combined enzymes (Alcalase, Pepsin, Trypsin, Chymotrypsin, Thermolysin,

© Woodhead Publishing Limited, 2011

230

Processed meats

Flavourzyme) have been assayed as potential systems to obtain bioactive peptides from both plasma proteins and Hb. The influence of the enzyme used and the degree of hydrolysis (DH) reached on the peptide’s activity have been clearly established, and there is general agreement on the interest in using blood as raw material for obtaining this kind of substance (Wei and Chiang, 2009). Angiotensin I-converting enzyme (ACE) promotes the conversion of angiotensin I in angiotensin II – a potent vasoconstrictor – and inactivates the vasodilator bradykinin. Thus, inhibitory activity on ACE plays an important role in the control of elevated blood pressure that is one of the major risk factors for cardiovascular diseases. Synthetic ACE inhibitors have been widely used as antihypertensive agents. Different studies carried out in the last years have identified several food proteins as sources of ACE inhibitory peptides (Matsui et al., 1999; Yamamoto and Takano, 1999; Pihlanto et al., 2000; Arihara et al., 2001; Yoshii et al., 2001; Hernández-Ledesma et al., 2005; Chiang et al., 2006; Hasan et al., 2006; Miguel et al., 2007; Otte et al., 2007;), thus making them the most extensively studied among the bioactive peptides generated from food proteins. Both blood plasma and Hb have also been investigated as potential sources of ACE-inhibitory substances. Hyun and Shin (2000) obtained ACE inhibitor peptides from bovine plasma and its isolated proteins, albumin and globulins, by enzymatic hydrolysis with Alcalase. In this study the most bioactive peptides were found in the fraction with molecular weights below 1000 Da. Janitha et al. (2002) found ACE inhibitory activity in hydrolysates of defibrinated bovine plasma treated with the microbial protease Flavourzyme; a 43% DH hydrolysate exhibited the highest activity having an IC50 (inhibitor concentration leading to 50% inhibition of ACE activity) of 1.08 mg/mL. The authors identified peptides containing Gly-Tyr-Pro, HisLeu(Ile), His-Pro-Tyr, His-Pro-Gly-His, Leu(Ile)-Phe, Ser-Pro-Tyr, and TyrPro-His sequence motifs. Some of these motifs correspond to sequences existing in bovine serum albumin, which permits consider bovine plasma as a potential source of ACE inhibitory peptides. Mito et al. (1996) demonstrated the in vivo effectiveness in decreasing blood pressure in spontaneously hypertensive rats by oral administration of some peptides obtained by proteolytic digestion with Alcalase of porcine haemoglobin. These authors identified four peptides that exhibited ACE inhibition activity: E-1 (Phe-Gln-Lys-Val-Val-Ala), E-2 (Phe-Gln-Lys-VaIVal-Ala-Gly), peptide 30-3 (Phe-Gln-Lys-Val-Val-Ala-Lys) and H-1 (GlyLys-Lys-Val-Leu-Gln) with IC50 of 5.8, 7.4, 2.1 and 1.9 μM, respectively. Yu et al. (2006) reported that hydrolysis of porcine haemoglobin carried out by pepsin in acidic conditions yields peptides with moderated ACEinhibitory capacity (IC50 values from 17.99 to 0.10 mg/mL). These authors identified two peptides corresponding to the α chain fragment (34–46) and to the β chain fragment (34–39) of porcine haemoglobin, with IC50 values of 4.92 and 6.02 μM, respectively. These fragments maintained inhibitory

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

231

activity even after incubation with gastrointestinal proteases, which suggests that these peptides might have a potential antihypertensive effect. Oxidant stress is a significant causative factor for several vascular diseases, and can cause extensive damage to biological macromolecules, such as DNA, proteins and lipids (Ames et al., 1993; Erdmann et al., 2008). Haemoglobin and its hydrolysates can develop antioxidant activities by different mechanisms: reducing power, ferrous ion chelating ability, and radical scavenging activity. Chang et al. (2007) found that porcine haemoglobin is able to act as antioxidant due to its chelating iron capacity and its reducing power, while porcine haemoglobin hydrolysates have radical scavenging activities, the latter being higher as the molecular weight of peptides was lower. Our group has also found remarkable antioxidant capacity in porcine haemoglobin intensely hydrolysed by trypsin followed by pepsin as described in Toldrà (2002). Since the late eighties morphine-like active peptides obtained through hydrolysis of bovine haemoglobin have also been described (Brantl et al. 1986). More recent studies have identified up to ten haemoglobin fragments exhibiting analgesic and opioid activities. These peptides have always been obtained by using pepsin at acidic conditions, and all of them have the common sequence Tyr-Pro-Trp-Thr (haemorphin-4), corresponding to the 34–37 fragment of the β-chain of bovine haemoglobin (Zhao and Piot, 1997). Froidevaux et al. (2008) have recently improved the preparation of Leu-Val-Val-haemorphin-7 (β 31–40) and Val-Val-haemorphin-7 (β 32–40) by using continuous liquid/liquid extraction coupled with aluminium oxide column during the haemoglobin hydrolysis by immobilised pepsin, so providing a potential process to obtain haemomorphin on a large scale. Antimicrobial potential of blood-derived peptides Research has been carried out on the use of natural peptides from different sources as antimicrobial additives (Mine et al., 2004; Muralidhara et al., 2007), with potential applications to produce safe and healthy foods. Daoud et al. (2005) and Nedjar-Arroume et al. (2006) obtained several peptide fractions exhibiting antibacterial activity against Micrococcus luteus A270, Listeria innocua, Escherichia coli and Salmonella Enteritidis through the peptic digestion of bovine haemoglobin at low degree of hydrolysis. The investigation of these hydrolysates revealed four new antibacterial peptides. Three of them corresponded to fragments of the α-chain of bovine Hb: α107–141, α137–141 and α133–141, and one peptide to the β-chain: β126– 145. Further studies carried out by the same research group (NedjarArroume et al., 2008) have evidenced that it is possible to purify and identify a total of 30 peptides with antibacterial activity, 24 of them from the α-chain corresponding to three peptide families: α1 derived from peptide α 1–32, α2 derived from peptide α 33–98 and α3 derived from peptide α 107–141; and 6 peptides from the β-chain of bovine Hb corresponding to families β1 and β2 derived from peptides β 1–30 and β 114–145, respectively. So, such

© Woodhead Publishing Limited, 2011

232

Processed meats

a high number of antibacterial peptides derived from bovine Hb could become useful as preservatives for storage and distribution of meat-based products.

9.3 Future trends Currently, blood-derived products suitable for human consumption in the value added meats market account only for a small amount of the total blood generated within the meat industry. The technical difficulties in collecting blood in adequate conditions in the industrial slaughterhouse environment, as well as economical considerations concerning retrofitting of existing slaughter lines and the weak market demand for blood-derived products, lead to an under-utilisation of such a rich and competitive source of valuable food proteins. A general improvement of existing blood collection facilities in slaughterhouses, which are cost-effective systems for blood collection and preservation, should be undertaken in order to obtain blood of a high quality, fit for exploitation in the manufacture of high quality added-value ingredients for the food industry. Engineering solutions together with studies demonstrating the worth of this by-product will likely help to this improvement. New techno-functional ingredients geared towards meeting specific food requirements within the varying processing conditions demanded in value added meat processing – i.e. pH, ionic strength, structure, fats or polysaccharides contents, etc. – may be formulated by taking advantage of the fractionated or modified major protein constituents of blood. With regard to gelling and interfacial properties, serum and plasma with altered protein profiles or isolated fractions, such as albumin and globulins, are promising products to be used in the development of tailor-made functional ingredients. Moreover, there are also ongoing studies based on the use of enzymatic modifications and/or high pressure treatments to improve functionality of blood proteins. Together with MTGase or tyrosinase, many other enzymatic systems could be assessed with the same purpose. This is an exciting area of development within the area of blood utilisation as a functional adjunct in value added meat manufacture. Furthermore, blood proteins can be degraded into numerous peptide fragments by enzymatic proteolysis and serve as source of bioactive peptides, which may be used to develop novel functional meat products. Also, some bioactive peptides can be potentially used for technological purposes. Recent studies have shown that peptides with antioxidative properties can be released from haemoglobin by hydrolysis with digestive enzymes. In the future, these antioxidant peptides may find applications in the prevention of fat and pigment oxidations and enhanced shelf-life stability of value added foods. Currently, the development of healthier meat products with reduced saturated fat content by partial substitution of pork back fat with

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

233

unsaturated oils is one among the trends of the meat industry, thus increasing the risk of rancidity. In addition, studies aiming at achieving the stabilisation of the bright red colour of haemoglobin by means of chelating and reducing agents, or even by using antioxidant peptides from the hydrolysis of blood proteins themselves, are currently being carried out. Stabilised haemoglobin will surely become an appreciated natural red colorant for the meat industry in the near future.

9.4 Sources of further information and advice This section contains information on some companies that are currently producing and commercialising functional food and feed products from animal blood, including the links to their websites, where useful documents can be downloaded. The Veos group (http://www.veos.be) consists of three companies which undertake the valorisation of porcine and bovine blood from slaughterhouses by producing functional proteins mainly destined for the human and pet food manufacturing markets. The companies are Veos NV in Zwevezele (Belgium), Vapran S.A. in Plemet (France) (http://www.vapran.com/) and Hemoprot in Mundo Novo (Brazil). Actipro® is the commercial brand name for the feed and pet food ingredients of the Veos Group (http://www. actipro.biz/). The ingredients for human food, specifically addressed to the meat industry, are sold under the brand name Vepro® (http://www.vepro. biz/). These products are: • dried, frozen or liquid plasma to increase yield, prevent cooking losses, form gels, enhance slicebility and bite of injected products, such are hams and cooked sausages; • globin powder (95% protein) that can be used as emulsifier in both warm and cold emulsions; • Hb, recommended for black pudding claiming to its excellent nutritional value and highly digestible organic iron content; and • a colourant agent, which consists on stabilised dried or liquid RBC to be used in cured and cooked meat products. Proliant Meat Ingredients (http://www.proliantmeatingredients.com) is part of a group of privately-held companies owned by The Lauridsen Group, Inc. (LGI), specialising in the development and production of ingredients for animal and human health and nutrition. The Proliant Meat Ingredients division has manufacturing locations at Lytton and Harlan in Iowa (USA) and at Granollers in Spain; the latter specialises in the production of pork plasma, whole pork blood and one meat pigment product, AproRED, most commonly used to enhance the reddish colour of processed meats. The ingredient is claimed to be best suited for applications such as fresh burgers,

© Woodhead Publishing Limited, 2011

234

Processed meats

uncooked sausages or meatballs, fermented dried sausages, smoked items and injected meat products. APC, Inc. (http://www.functionalproteins.com/) and BHJ (http://www.bhj.dk/) can be found among the Proliant Meat Ingredients’ sister companies. APC is a company that since 1981 has been providing functional proteins from blood plasma for feed and industrial use. The company has issued several patents related to processing and feeding plasma proteins. It has offices and manufacturing facilities in the United States, Canada, Spain and Northern Ireland and sales departments covering Asia Pacific, Europe, Latin America and North America. BHJ is an international supplier of ingredients and meat raw materials for the food, pet food, feed and pharmaceutical industries headquartered in Denmark. BHJ Protein Foods is a manufacturer of functional animal proteins, which are marketed to the meat processing industry under the brand name SCANPROTM. Sonac (http://www.sonac.biz), formerly Harimex B.V. in Loenen (Netherlands), processes animal-based raw materials to produce ingredients such as proteins, fats, gelatines, etc. Sonac is a supplier of animal proteins, such as frozen plasma, concentrated plasma powder, stabilised haemoglobin powder and a fresh meat binding agent made from two plasma-derived proteins: fibrinogen and thrombin. Fibrimex® is the brand name for the meat cold-binding product developed by TNO Nutrition and Food Research in the Netherlands which is produced and commercialized by Sonac Loenen, in Europe, and by FX Technology, in USA (www.fibrimex.com). Relative to blood collecting equipments, it is worth to say that the MPS Group (Meat Processing Systems) (www.mps-group.nl) is the supplier of the ANITEC blood collection and processing equipment (http://www. anitec.se/). ANITEC is an integrated hollow knife system that allows the hygienic collection of about 85% of blood from every animal, suitable for edible purposes, and helps the industry to hoist its profitability by improving the efficiency and increasing the utilisation of blood from slaughtered animals.

9.5 References álvarez c, bances m, rendueles m and díaz m (2009), ‘Functional properties of isolated porcine blood proteins’, Food Science and Technology, 44, 807–814. ames b n, shigenaga m k and hagen t m (1993), ‘Oxidants, antioxidants, and the degenerative diseases of aging’, Proceedings of the National Academy of Sciences USA, 90, 7915–7922. antonini e and brunori m (1971), Hemoglobin and myoglobin in their reactions with ligands. North-Holland, Amsterdam, vol. 21, 123–125. arihara k, nakashina y, mukai t, ishikawa s and itoth m (2001), ‘Peptide inhibitors for angiotensin I-converting enzyme from enzymatic hydrolysates of porcine skeletal muscle proteins’, Meat Science, 57, 319–324. aubes-dufau i and combes d (1997), ‘Effect of different proteases on bitterness of haemoglobin hydrolysates’, Applied Biochemistry and Biotechnology, 67, 127–138.

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

235

auvinen j (1992), ‘Globin – a new functional protein for the food industry’, International Food Ingredients, 2, 10–13. boffey p m (1976), ‘Color additives: botched experiment leads to banning of red dye no. 2’, Science, 191(4226), 450–451. boles j a and shand p j (1998), ‘Effect of comminution method and raw binder system in restructured beef’, Meat Science, 49, 297–301. brantl v, gramsch c, lottspeich f, mertz r, jaeger k h and herz a (1986), ‘Novel opioid peptide derived from hemoglobin: hemorphins’, European Journal of Pharmacology, 125, 309–310. breer c (1978), ‘Hygienic production and use of blood plasma in the manufacture of meat products’, Fleischwirtschaft, 58, 1649–1651. brekke c j and smith d m (1985), ‘Enzymatic modification of the structure and functional properties of mechanically deboned fowl proteins’, Journal of Agricultural and Food Chemistry, 33, 631–637. burnouf t (2007), ‘Modern plasma fractionation’, Transfusion Medicine Reviews, 21, 101–117. carretero c and parés d (2000), ‘Improvement of the microbiological quality of blood plasma for human consumption purposes’, Recent Research Development in Agricultural and Food Chemistry, 4, 203–216. chan w k m, faustman c, yin m and decker e a (1997), ‘Lipid oxidation induced by oxymyoglobin with involvement of H2O2 and superoxide anion’, Meat Science, 46, 181–190. chang c y, wu k c and chiang s h (2007), ‘Antioxidant properties an protein compositions of porcine hemoglobin hydrolysates’, Food Chemistry, 100, 1537–1543. cheftel j c, cuq j l and lorient d (1989), Proteínas alimentarias. Spain, Acribia SA, 50–75. chiang w d, tsou m j, tsai z y and tsai t c (2006), ‘Angiotensin I-converting enzyme inhibitor derived from soy protein hydrolysate and produced by using membrane reactor’, Food Chemistry, 98, 725–732. choi y s, choi j h, han d j and kim h y (2009), ‘Physicochemical and sensory characterization of Korean blood sausage with added rice bran fiber’, Korean Journal for Food Science of Animal Resources, 29, 260–268. cironeanu i, danicel g and dragulici d (1973), ‘Production of blood plasma and its use in the meat industry’, Industria Alimentara, 24, 667–670. cofrades s, guerra m a, carballo j, fernàndez-martin f and jiménez colmenero f (2000), ‘Plasma protein and soy fiber content effect on bologna sausage properties as influenced by fat level’, Journal of Food Science, 65, 281–287. cohn e j, strong l e, hughes w l, mulford d j, asworth j n, melin m and taylor h l (1946), ‘Preparation and properties of serum and plasma proteins. IV. A system for the separation into fractions of the protein and lipoprotein components of biological tissues and fluids’, Journal of the American Chemical Society, 68, 459. Council Directive 77/99/EC of 21 December 1976, on health problems affecting intra- community trade in meat products. crenwelge d d, dill c w, tybor p t and landmann w a (1974), ‘A comparison of emulsification capacities of some protein concentrates’, Journal of Food Science, 39, 175–177. dailloux s, djelveh g, peyron a and oulion c (2002), ‘Rheological behaviour of blood plasmas concentrated by ultrafiltration and by evaporation in relation to liquid–gel transition temperature’, Journal of Food Engineering, 55, 35–39. damodaran s (1997), ‘Food proteins: an overview’. In: Damodaran S and Paraf A (Eds.), Food Proteins and their Applications, New York, Marcel Dekker Inc., 1–24.

© Woodhead Publishing Limited, 2011

236

Processed meats

daoud r, dubois v, bors-dodita l, nedjar-arroume n, krier f, chihib n e, marya p, kouach m, briand g and guillochon, d (2005), ‘New antibacterial peptide derived from bovine hemoglobin’, Peptides, 26, 713–719. dàvila e, saguer e, toldrà m, carretero c and parés d (2006), ‘Preservation of porcine blood quality by means of lactic acid bacteria’, Meat Science, 73, 386–393. dàvila e, parés d and howell n k (2007a), ‘Studies on plasma protein interactions in heat-induced gels by differential scanning calorimetry and FT-Raman spectroscopy’, Food Hydrocolloids, 21, 1144–1152. dàvila e, parés d, cuvelier g and relkin p (2007b), ‘Heat-induced gelation of porcine blood plasma proteins as affected by pH’, Meat Science, 76, 216–222. dàvila e, saguer e, toldrà m, carretero c and parés d (2007c), ‘Surface functional properties of blood plasma protein fractions’, European Food Research and Technology, 226, 207–214. de vuono m, penteado c, lalojo f m and pereire dos santos n (1979), ‘Functional and nutritional properties of isolated bovine blood proteins’, Journal of the Science of Food and Agriculture, 30, 809–815. dolatowski z j (1985), ‘Effects of blood plasma on quality. Manufacture of hamtype products from horse meat’, Fleischerei, 36, 700–702. dolatowski z j (1986), ‘Influence of blood plasma on the quality of smoked ham from PSE meat’, Fleischwirtschaft, 66, 225–226, 229–231. duarte r t, simoes m c c and sgarbieri v c (1999), ‘Bovine blood components: fractionation, composition, and nutritive value’, Journal of Agricultural and Food Chemistry, 47, 231–236. duhard v, garnier j c and megard d (1997), ‘Comparison of the stability of selected anthocyanin colorants in drink model systems’, Agro Food Industry Hi-Tech, 8, 28–34. erdmann k, cheung b w y and schröder h (2008), ‘The possible roles of foodderived bioactive peptides in reducing the risk of cardiovascular disease’, Journal of Nutritional Biochemistry, 19, 643–654. erikson g and von bockelmann i (1975), ‘Ultrafiltration of animal blood serum: technology and microbiology’, Processing Biochemistry, 10, 11–14. faostat (2007), Livestock primary production. Available from: http://faostat.fao.org/ site/569/DesktopDefault.aspx?PageID=569#ancor [accessed 26 May 2009]. feiner g (2006), Meat Products Handbook: Practical science and technology, Cambridge/Boca Raton, FL, Woodhead Publishing/CRC Press LLC. fort n, lanier t c, amato p, carretero c and saguer e (2008) ‘Simultaneous application of microbial transglutaminase and high hydrostatic pressure to improve heat induced gelation of pork plasma’, Meat Science, 80, 939–943. fort n, kerry j, carretero c, kelly a and saguer e (2009), ‘Cold storage of porcine plasma treated with microbial transglutaminase under high hydrostatic pressure. Effects on the heat-induced gel properties’, Food Chemistry, 115, 602–608. fretheim k, nordal j and slinde e (1979), ‘Production of a flavouring with meat-like sensory properties from slaughter animal blood’, Proceedings of the European Meeting of Meat Research Workers, 25, 10. froidevaux r, vanhoute m, lecouturier d, dhulster p and guillochon d (2008), ‘Continuous preparation of two opioid peptides and recycling of organic solvent using liquid/liquid extraction coupled with aluminium oxide column during haemoglobin hydrolysis by immobilized pepsin’, Process Biochemistry, 43, 431–437. georgakis s a, vareltzis k, zetou f and tsiaras i (1986), ‘The use of blood plasma proteins as an additive in cooked meat products’, Proceedings of the European Meeting of Meat Research Workers, 32, 7. golz j t, helgeson d l, zetocha d f and petry t a (1991), ‘Preliminary economic feasibility of processing a natural red food colorant from purple-hull sunflower

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

237

in North Dakota’, Agricultural Economics Report, 273. North Dakota State University, Fargo, USA. guzman j c, mcmillin k w, bidner t d, dugas-sims s and godber j s (1995), ‘Texture color and sensory characteristics of ground beef patties containing bovine blood proteins’, Journal of Food Science, 60, 657–660. hartmann, r and meisel h (2007), ‘Food-derived peptides with biological activity: from research to food applications’, Current Opinion in Biotechnology, 18, 163–169. hasan, f, kitagawa m, kumada y, hashimoto n, shiiba m, katoh s and terashima m (2006), ‘Production kinetics of angiotensin-I converting enzyme inhibitory peptides from bonito meat in artificial gastric juice’, Process Biochemistry, 41, 505–511. hernández-ledesma b, miralles b, amigo l, ramos m and recio i (2005), ‘Identification of antioxidant and ACE-inhibitory peptides in fermented milk’, Journal of the Science of Food and Agriculture, 85, 1041–1048. herrero a m, cambero m i, ordóñez j a, castejón d, romero de avila m d and de la hoz l (2007), ‘Magnetic resonant imaging rheological properties and physicochemical of meta systems with fibrinogen and thrombin’, Journal of Agricultural and Food Chemistry, 55, 9357–9364. herrero a m, cambero m i, ordóñez j a, de la hoz l and carmona p (2009) ‘Plasma powder as cold-set binding agent for meta system: rheological and Raman spectroscopy study’, Food Chemistry, 113, 493–499. howell n k and lawrie r a (1984a), ‘Functional aspects of blood plasma proteins. II. Gelling properties’, Journal of Food Technology, 19, 289–295. howell n k and lawrie r a (1984b), ‘Functional aspects of blood plasma proteins. III. Interaction with other proteins and stabilizers’, Journal of Food Technology, 19, 297–313. hyun c k and shin h k (2000), ‘Utilization of bovine blood plasma proteins for the production of angiotensin I converting enzyme inhibitory peptides’, Process Biochemistry, 36, 65–71. in m j, chae h j and oh n s (2002), ‘Process development for hemeenriched peptide by enzymatic hydrolysis of haemoglobin’, Bioresource Technology, 84(1), 63–68. janitha p k, wanasundara p d, ross, a r s, amarowicz r, ambrose s j, pegg r p and shand p j (2002), ‘Peptides with angiotensin I-converting enzyme (ACE) inhibitory activity from defibrinated, hydrolyzed bovine plasma’, Journal of Agricultural and Food Chemistry, 50, 6981–6988. jelenikova j and pipek p (2006), ‘Blood proteins application in meat products’, Maso, 17, 18–21. jiménez-colmenero f (1996), ‘Technologies for developing low-fat meat products’, Trends in Food Science and Technology, 72, 41–48. johns a m, birkinshaw l h and ledward d a (1989), ‘Catalysts of lipid oxidation in meat products’, Meat Science, 25, 209–220. kendrick j and watts b m (1969), ‘Acceleration and inhibition of lipid oxidation by haem compounds’, Lipids, 4, 454–458. king j, depablo s and deoca f m (1989), ‘Evaluation of gelation and solubility of bovine plasma-protein isolates’, Journal of Food Science, 54, 1381–1382. korhonen h (2009), ‘Milk-derived bioactive peptides: from science to applications’, Journal of Functional Foods, 1, 177–187. korhonen h and pihlanto a (2003), ‘Food-derived bioactive peptides – opportunities for designing future foods’, Current Pharmaceutical Design, 9, 1297–1308. liu x q, yonekura m and tsutsumi m (1994a), ‘Gel formation of globin prepared by acid-acetone method and globin hydrolyzates’, Nippon Shokuhin Kogyo Gakkaishi, 41, 178–183.

© Woodhead Publishing Limited, 2011

238

Processed meats

liu x q, yonekura m and tsutsumi m (1994b), ‘Gel properties of globin hydrolyzates’, Nippon Shokuhin Kogyo Gakkaishi, 41, 196–201. liu x q, yonekura m and tsutsumi m (1996), ‘Restrictive hydrolysis of globin by citric acid’, Nippon Shokuhin Kogyo Gakkaishi, 43, 141–145. lópez a m, morera s and planiol j (1992), ‘Utilización de proteína plasmática en la formulación de embutidos cárnicos curados’, Alimentación equipos y tecnología September, 117–121. marc j and vancikova o (1978), ‘Changing the sensory properties of blood for food purposes’, Prumysl Potravin, 29, 369. matsui t, li c h and osajima y (1999), ‘Preparation and characterization of novel bioactive peptides responsible for angiotensin I-converting enzyme inhibition from wheat germ’, Journal of Peptide Science, 5, 289–297. miguel m, manso m, aleixandre a, alonso m j, salaices m and lopez-fandino r (2007), ‘Vascular effects, angiotensin I-converting enzyme (ACE)-inhibitory activity, and anti hypertensive properties of peptides derived from egg white’, Journal of Agricultural and Food Chemistry, 55, 10615–10621. mine y, ma f p and lauriau s (2004), ‘Antimicrobial peptides released by enzymatic hydrolysis of hen egg white lysozyme’, Journal of Agricultural and Food Chemistry, 52, 1088–1094. mito k, fujii m, kuwahara m, matsumura n, shimizu t, sugano s, and karaki h (1996), ‘Antihypertensive effect of angiotensin I-converting enzyme inhibitory peptides derived from hemoglobin’, European Journal of Pharmacology, 304, 93–98. moure f, rendueles m and díaz m (2003), ‘Coupling process for plasma protein fractionation using ethanol precipitation and ion exchange chromatography’, Meat Science, 64, 391–398. muralidhara c, haque e and chand r (2007), ‘Antimicrobial peptides purified from bovine milk fermented with Lactobacillus delbrueckii ssp bulgaricus’. Milchwissenschaft-Milk Science International, 62, 62–65. nakamura t, numata m, yoshino y and itosawa k (1983), ‘Application of dried plasma in processed meat products’, Journal of Japanese Society of Food Science & Technology, 30, 283–289. nakamura r, hayakawa s, yasuda k and sato y (1984), ‘Emulsifying properties of bovine blood globin: a comparison with some proteins and their improvement’, Journal of Food Science, 49, 102–104. nedjar-arroume n, dubois-delval v, miloudi k, daoud r, krier f, kouach m, briand g and guillochon d (2006), ‘Isolation and characterization of four antibacterial peptides from bovine hemoglobin’, Peptides, 27, 2082–2089. nedjar-arroume n, dubois-delval v, yaba adje e, traisnel j, krier f, mary , kouach m, briand g and guillochon d (2008), ‘Bovine hemoglobin: an attractive source of antibacterial peptides’, Peptides 29, 969–977. nuthong p, benjakul s and prodpran t (2009), ‘Effect of phenolic compounds on the properties of porcine plasma protein-based film’, Food Hydrocolloids, 23, 736–741. ockerman h w and hansen c l (2000), Animal By-product Processing & Utilization, Lancaster, PA, Technomic Publishing Co. oord a h a and wesdorp j j (1979), ‘Decolouration of slaughterhouse blood by treatment with hydrogen peroxide, Proceedings of the European Meeting for Meat Research Workers, 25, 825–828. o’riordan d, kinsella j e, mulvihill d m and morrissey p a (1989), ‘Gelation of plasma-proteins’, Food Chemistry, 33, 203–214. oshodi a a and ojokan e o (1997), ‘Effect of salts on some of the functional properties of bovine plasma protein concentrate’, Food Chemistry, 59, 333– 338.

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

239

otte j, shalaby s m, zakora m, pripp a h and. ei-shabrawy s a (2007), ‘Angiotensinconverting enzyme inhibitory activity of milk protein hydrolysates: effect of substrate, enzyme and time of hydrolysis’, International Dairy Journal, 17, 488–503. parés d and ledward d a (2001), ‘Emulsifying and gelling properties of porcine blood plasma as influenced by high-pressure processing’, Food Chemistry, 74, 139–145. parés d, saguer e, saurina j, suñol j j and carretero c (1998a), ‘Functional properties of heat induced gels from liquid and spray dried porcine blood plasma as influenced by pH’, Journal of Food Science, 63, 958–961. parés d, saguer e, saurina j, suñol j j, toldrà m and carretero c (1998b), ‘DSC study of the effects of high pressure and spray-drying treatment on porcine plasma’, Journal of Thermal Analysis and Calorimetry, 52, 837–844. parés d, saguer e, toldrà m and carretero c (2000), ‘Effect of high pressure processing at different temperatures on protein functionality of porcine blood plasma’, Journal of Food Science, 65, 486–490. parés d, saguer e, toldrà m and carretero c (2001), ‘High hydrostatic pressure as a method to reduce microbial contamination of porcine blood plasma’, Food Science and Technology International, 7(2), 117–121. parés d, zamora l, saguer e and carretero c (2004), ‘Acid lactic bacteria as biopreservative cultures in porcine blood for human consumption’, FoodInfo Online Features 2. http://www.foodsciencecentral.com/fsc/ixid13082. pietrasik z, jarmoluk a and shand p j (2005), ‘Textural and hydration properties of pork meat gels processed with non-muscle proteins and carrageenan’, Polish Journal of Food and Nutrition Science, 14/55, 145–150. pietrasik z, jarmoluk a and shand p j (2007), ‘Effect of non-meat proteins on hydration and textural properties of pork meat gels enhanced with microbial transglutaminase’, Lebensmittel -Wissenschaft und-Technologie, 40, 915–920. pihlanto a, koskinen p, piilola k, tupasela t and korhonen h (2000), ‘Angiotensin I-converting enzyme inhibitory properties of whey protein digests: concentration and characterization of active peptides’, Journal of Dairy Research, 67, 53–64. piot j m, guillochon d and thomas d (1986), ‘Preparation of decolorized peptides from slaughter-house blood’, MIRCEN Journal, 2, 359–364. putnam f w (1975), The Plasma Proteins: Structure, function, and genetic control, New York, Academic Press. raëker m o and johnson l a (1995). ‘Thermal and functional properties of bovine blood plasma and egg white proteins’, Journal of Food Science, 60, 685–690, 706. ramos-clamont g, fernández-michel s, carrillo-vargas l, martinez-calderón e and vázquez-moreno l (2003), ‘Functional properties of protein fractions isolated from porcine blood’, Journal of Food Science, 68, 1196–1200. ranken m d (1980), ‘Applications of blood proteins’. In Grant R A (Ed.), Applied Protein Chemistry. London, Applied Science Publishers Ltd, 169–180. Regulation (EC) No 1774/2002 of the Parliament and of the Council of 3 October 2002 laying down health rules concerning animal by-products not intended for human consumption (OJ L 273, 10.10.2002, p. 1). reizenstein p (1980), ‘Hemoglobin fortification of food and prevention of iron deficiency with heme iron’, Acta Medica Scandinavian Supplement, 629, 1–47. rito-palomares m, dale c and lyddiatt a (1998) ‘Aqueous two-phase fractionation of biological suspensions for protein recovery from bovine blood’, Biotechnology Techniques, 22(9), 711–714. rogov i a, lipatov n n, bogatyrev a n, efimov a v, zabashta a g and titov e i (1981), Principles of production and prospects of utilization in meat product technology of textured protein products based on blood plasma. Proceedings of the European Meeting of Meat Research Workers, 27(1), Vienna.

© Woodhead Publishing Limited, 2011

240

Processed meats

rwan j-h and chang w-h (1996), ‘Separation of globin from pig hemoglobin by pectin’, Food Science, Taiwan, 23, 174–183. sabljak-uglesic s and prilika b (1979), ‘Collection and processing of blood for food purposes’, Tehnologija Mesa, 20, 107–111. saguer e, altarriba s, lorca c, parés d, toldrà m and carretero c (2003), ‘Color stabilization of spray-dried porcine red blood cells using nicotinic acid and nicotinamide’, Food Science and Technology International, 9(4), 301–307. saguer e, dàvila e, toldrà m, fort n, baixas s, carretero c and parés d (2007a), ‘Effectiveness of high pressure processing on the hygienic and technological quality of porcine plasma from biopreserved blood’, Meat Science, 76(1), 189–193. saguer e, fort n, parés d, toldrà m and carretero c (2007b), ‘Improvement of gelling properties of porcine blood plasma using microbial transglutaminase’, Food Chemistry, 101, 49–56. saguer e, fort n, alvarez p, sedman j and ismail a a (2008), ‘Structure–functionality relationships of porcine plasma proteins probed by FTIR spectroscopy and texture analysis’, Food hydrocolloids, 22, 459–467. sakata r, guisong l and nagata y (1992), ‘Nitrosation of haemoglobin from animal bood as a colorant of meat products’, Animal Science and Technology, 63, 1247–1252. sakata r, yoshida n, morita h and nagata y (1993) ‘Augmentation of cooked cured meat colour by nitrosohaemoglobin prepared from cattle blood’, Animal Science and Technology, 64, 855–861. salvador p, toldrà m, carretero c, parés d and saguer e (2009a), ‘Color stabilization of porcine hemoglobin during spray-drying and powder storage by combining chelating and reducing agents’, Meat Science, 83(2), 328–333. salvador p, toldrà m, saguer e, carretero c and parés d (2009b), ‘Microstructurefunction relationships of heat-induced gels of porcine haemoglobin’, Food Hydrocolloids, 23, 1654–1659. salvador p, saguer e, parés d, carretero c and toldrà m (2010), ‘Foaming and emulsifying properties of porcine red cell protein concentrate’, Food Science and Technology International, 16(4), 289–296. sanina z (1971), ‘Addition of blood plasma to cut meat for the manufacture of frankfurters improves yield and quality’, Myasnaya Industriya SSSR, 42, 29. sato y, hayakawa s and hayakawa m (1981), ‘Preparation of blood globin through carboxymethyl cellulose chromatography’, Journal of Food Technology, 16, 81–91. satterlee l d (1975), ‘Improving utilization of animal by-products for human foods – a review’, Journal of Animal Science, 41, 687–697. savostin a s (1977), ‘Utilization of waste and by-products from meat and milk processing industries’, Pishchevaya Promyshlennost, 3, 6–9. schaper bizzotto c, capobiango m and coelho silvestre m p (2005), ‘Evaluation of functional properties of a blood protein’, Pakistan Journal of Nutrition, 4, 11–16. sephton s w and clegg a (1993), ‘Production of Blood Fraction Hydrolysates and the Use of Blood and Milk Hydrolysates in Finely Comminuted Meat Products’, Meat Industry Research Institute of New Zealand, Hamilton, New Zealand. shtenberg a i and gavrilenko e v (1970), ‘Effect of amaranth food dye on reproduction and progeny of albino rats’, Voprosy Pitaniya, 29, 66–73. silva v d m and silvestre m p c (2003), ‘Functional properties of bovine blood plasma intended for use as a functional ingredient in human food’, Lebensmittel-Wissenschaft und-Technologie, 36, 709–718. silva j g, morais h a and silvestre m p c (2003), ‘Comparative study of the functional properties of bovine globin isolates and sodium caseinate’, Food Research International, 36, 73–80.

© Woodhead Publishing Limited, 2011

Blood by-products as ingredients in processed meat

241

song i s, lee s h, kang t s and song k w (1984), ‘Spinning and utilization of blood plasma and protein isolates from meat industry by-products’, Korean Journal of Animal Science, 26, 303–309. swingler g r, naylor p e l and lawrie r a (1978), ‘Microbial aspects of protein recovery from meat industry by-products’, Meat Science, 3, 83–95. synowiecki j, jagielka r & shahidi f (1996), ‘Preparation of hydrolysates from bovine red blood cells and their debittering following plastein reaction’, Food Chemistry, 57, 435–439. toldrà m (2002), Revaloració de la fracció cel·lular de la sang de porc precedent d’escorxadors industrials, Thesis dissertation, Department of Chemical Agricultural and Food Technology Engineering, University of Girona. toldrà m, busquets a, saguer e, parés d and carretero c (2002), ‘Effects of high hydrostatic pressure treatment on porcine blood red cells fraction’, Food Science and Technology International, 8(1), 41–48. toldrà m, elias a, parés d, saguer e and carretero c (2004), ‘Functional properties of a spray-dried porcine red blood cell fraction treated by high hydrostatic pressure’, Food Chemistry, 88, 461–468. toldrà m, dàvila e, saguer e, fort n, salvador p, parés d and carretero c (2008), ‘Functional and quality characteristics of the red blood cell fraction from biopreserved porcine blood as influenced by high pressure processing’, Meat Science, 80, 380–388. torres m r, marin f r, ramos a j and soriano e (2002), ‘Study of operating conditions in concentration of chicken blood plasma proteins by ultrafiltration’, Journal of Food Engineering, 54, 215–219. tybor p t, dill c w and landmann w a (1973), ‘Effect of decolorization and lactose incorporation on the emulsification capacity of spray-dried blood protein concentrates’, Journal of Food Science, 38, 4–7. tybor p t, dill c w and landmann w a (1975), ‘Functional properties of proteins isolated from bovine blood by a continuous pilot process’, Journal of Food Science, 40, 155–159. viana f r, silva v d m, delvivo f m, bizzotto c s and silvestre m p c (2005), ‘Quality of ham pâté containing bovine globin and plasma as fat replacers’, Meat Science, 70, 153–160. wei j t and chiang b h (2009), ‘Bioactive peptide production by hydrolysis of porcine blood proteins in a continuous enzymatic membrane reactor’, Journal of the Science of Food and Agriculture, 89, 372–378. wijngaards g and paardekooper e j c (1987), ‘Preparation of a composite meat product by means of an enzymatically formed protein gel’. In Trends in Modern Meat Technology 2 Proceedings of the International Symposium, The Netherlands, Eds PS van Roon Krol and JH Houben Pudoc, Wageningen, 125–129. wismer-pedersen j (1980), ‘Full utilitzation of blood from slaughter animals in manufacture of meat products. Chemical decoloration of haemoglobin’, Fleischwirtschaft, 60, 987–990 wismer-pedersen j (1988), ‘Use of haemoglobin in foods – a review’, Meat Science, 24, 31–45. wismer-pedersen j (1989), ‘A process for producing a substantially haem-free blood protein’, Patent Pub. No. WO/1989/000816 – International Application No. PCT/ DK1988/000127 yamamoto n and takano t (1999), ‘Antihypertensive peptides derived from milk proteins’, Nahrung-Food, 43, 159–164. yoshii h, tachi n, ohba r, sakamura o, takeyama h and itani t (2001), ‘Antihypertensive effect of ACE inhibitory oligopeptides from chicken egg yolks’, Comparative Biochemistry and Physiology C – Toxicology & Pharmacology, 128, 27–33.

© Woodhead Publishing Limited, 2011

242

Processed meats

young c r, lewis r w, landmann w a and dill c w (1973), ‘Nutritive value of globin and plasma protein fractions from bovine blood’, Nutrition Reports International, 8, 211–217. yu y, hua j, miyaguchi y, bai x, dua y and lin b (2006), ‘Isolation and characterization of angiotensin I-converting enzyme inhibitory peptides derived from porcine hemoglobin’, Peptides, 27, 2950–2956. zhao q and piot j m (1997), ‘Investigation of inhibition angiotensin-converting enzyme (ACE) activity and opioid activity of two hemorphins, LVV-hemorphin-5 and VV-hemorphin-5, isolated from a defined peptic hydrolysate of bovine hemoglobin’, Neuropeptides, 31, 147–153.

© Woodhead Publishing Limited, 2011

10 Utilisation of hydrocolloids in processed meat systems R. McArdle and R. Hamill, Teagasc Food Research Centre, Ireland and J. P. Kerry, University College Cork, Ireland.

Abstract: This chapter examines current challenges faced by the food industry in delivering meat products with desired characteristics and how hydrocolloids could be used to meet these challenges. Hydrocolloids perform a number of functions, including; thickening, gelling and binding, coating, stabilisation of foams, emulsions and dispersions and stabilisation of pH. Previous research carried out with hydrocolloids from many different sources, such as plants (trees, seeds, tubers and pulses), animal (milk, meat, animal by-products) and microorganisms (bacteria, fungi and yeast) is also discussed. Key words: hydrocolloids, gelling agent, processed meats, improved product formulation.

10.1 Introduction The overall objective of this chapter is to examine the fundamental properties of processed meat products, to explore the challenges in delivering meat products with desired characteristics and to review recent research on the roles of hydrocolloid additives in meeting these challenges. Examples of current challenges faced by the food industry in the area of ingredient interaction include the need for improved meat product formulation in relation to cost and added value, in relation to reformed product development, in relation to salt, fat and phosphate reduction and in relation to exploring the potential of meat products as delivery mechanisms for healthpromoting compounds. These challenges must be addressed while retaining or improving technological functionality (water-holding capacity and preservation) and sensory performance (appearance, mouthfeel, texture, juiciness and flavour). Today’s consumers are health and nutrition conscious and prefer to avoid food products with high fat or salt contents. Ground beef or pork

© Woodhead Publishing Limited, 2011

244

Processed meats

meat products generally contain approximately 20–30% fat and salt levels of between 2.0 and 3.4 g. It is important for the meat industry to reduce both the fat and salt content of their products and offer reduced fat/lower salt palatable meat products that satisfy consumer demands. Because fat is essential in providing soft texture, juiciness and flavour, a reduction in fat, without inclusion of some compensating ingredient, may have a significant and negative impact on the organoleptic quality of these products (Trius and Sebranek, 1996). Salt in meat products plays a role in flavour and texture development in meat products. The addition of salt to meat improves water and fat binding properties and results in a desirable gel formation when cooked. Salt reduction has proven to be a major challenge for the food industry (Terrell, 1983). In order to achieve favourable product characteristics in reducing fat and salt content, several hydrocolloids capable of improving water binding and texture are of interest to meat processors (Andres et al., 2006). The term hydrocolloid refers to a range of polysaccharides and proteins that are used in a variety of industries to perform a number of functions, including; thickening, gelling and binding, coating, syneresis control, stabilisation of foams, emulsions and dispersions, stabilisation of pH, enhancement of heat resistance and salt tolerance, creation of suspensions, etc. The hydrocolloids used within the food industry today are derived from many different sources, such as plants (trees, general plant materials, seeds, tubers and pulses), animal (milk, meat, animal by-products) and microorganisms (bacteria, fungi and yeast) (Fig. 10.1).

Protein Animal Casein Whey Gelatine Blood protein

Polysaccharides

Plant Soy

Starch Corn Wheat Pea Potato Tapioca

Microbial Xanthan Curdlan Gellan Yeast extract

Cellulose

Enzymes Transglutaminase

Miscellaneous Sugars Maltodextrin

Gums Fibre Chitosan/chitin Guar β glucan Locust bean Konjac glucomannan Alginate Carrageenan Pectins Karaya Ghatti Tragacanth Tara Tamarid

Fig. 10.1 Origin of different types of hydrocolloids used in the food industry (adapted from Cutter, 2006).

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

245

Hydrocolloids are high molecular weight hydrophilic polymers which contain polar or charged functional groups, rendering them soluble in water. The concept of ‘healthier’ products also includes what are known as ‘functional foods’. Functional foods are an emerging field in food science due to their health-promoting or disease-preventing properties, in addition to their basic nutritional value (Jiménez-Colmenero et al., 2001). Many hydrocolloids (e.g. locust bean gum, guar gum, konjac mannan, xanthan) have been shown to reduce blood cholesterol levels. Other hydrocolloids (e.g. inulin) have been shown to have prebiotic effects (Hecker et al., 1998). Enhancing the ability of meat products to provide an excellent sensory experience, while meeting salt and fat targets and assessing the relevance of novel meat products as a delivery mechanism for bioactive compounds is the target of much research at present. Hydrocolloids are ingredients that have grown in importance in recent years with a view to meeting these challenges and new opportunities.

10.2 The meat matrix Comminuted meat products are complex mixtures that form gels in response to heat treatment. Raw and cooked meat products can be thought of as a complex ‘matrix’ of interacting components. The raw material, muscle tissue, is a biological system comprising muscle fibres, connective tissue, fat and water in variable proportions. Beefburgers and emulsion-type sausages differ with respect to factors such as meat content and the degree of comminution, but they also have much in common. A coarse ground beefburger is composed of randomly distributed intact meat fibres and fibre bundles (50–70%), fat, seasoning and water. Sausages are made by chopping meat with the addition of water and salt into a fine homogenate, in which the pork fat is usually further dispersed and emulsified (Andersson et al., 2000). Through comminution, the muscle cells are broken down and the proteins are extracted. This processing permits molecular interactions to occur among the added components. Solubilisation of muscle protein by interaction with salt solutions is an important physiochemical process that follows comminution and blending of meat (Schmidt et al., 1981, Xiong, 2004). The salt soluble proteins then form a surrounding layer at the surface of the released fat and a stable emulsion is formed (Fig. 10.2). The raw matrix, or meat batter, thus represents a multiphase system (Hermansson, 1986) wherein the proteins are present in different phases; the protein matrix, the aqueous (dispersed) and the interfacial (continuous) protein film around fat globules (Gerrard, 2002). The types and amount of protein present in each phase affect the stability and textural properties of the cooked product (Hermansson, 1986). Reforming muscles from pieces of whole muscle to form an intact product which has intact fibres and therefore characteristic of a whole

© Woodhead Publishing Limited, 2011

246

Processed meats

Myofibril

Fat globule membrane

Salt-soluble protein

Protein cross-link

Collagen fibril

Fig. 10.2 Schematic representation of a typical meat emulsion (Xiong, 2004). Courtesy of Elsevier.

muscle can provide convenient and more profitable utilisation of lower value meat cuts. Binding of muscles in reformed meats can be achieved by: (a) thermally induced gelation (cooking) of the myofibrillar proteins extracted with salt and phosphate, giving adhesion between meat pieces or (b) cold-set binding through chemically induced gelation of a binding agent or (c) a combination of protein extraction and cold-set binding (Boles and Shand, 1998). The cooking step is the final key process in the development of the matrix, with the type of matrix formed dependent on the relatively dispersed or aggregated state of the protein, prior to gelation. The structure of the cooked matrix is therefore different in burgers and sausages. Upon cooking, the higher occurrence of whole fibre and pieces of fibres in burgers causes more shrinkage in burgers compared with emulsion-type sausages (Tornberg, 2005). In sausage products, higher amounts of myofibrillar proteins are extracted; thus a stronger gel is formed after heat treatment. The complex meat system consists not only of dissolved proteins but also of insoluble components such as meat fibres, connective tissue and fat in variable proportions. The amount and state of these components also have a large impact on their gelation properties (Andersson et al., 2000).

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

247

10.3 Challenges faced by the meat industry today Obesity, cardiovascular disease, stroke and cancer have been implicated with high fat intake. This has led to increased demand by consumers for low fat meat products. A variety of quality attributes in emulsion-type products are affected by fat reduction, including; texture, sensory attributes, chemical composition and cook yield (Rogers, 2001). Replacement of fat with water results in lower cooking yields, lower texture profile analysis (TPA) values and in general, inferior sensory qualities (Claus and Hunt, 1991; Hsu and Chung, 1999). Other investigations have found that if the fat content is reduced and meat content is simultaneously increased to compensate for the loss of fat, firmness increases and water-holding capacity decreases (Cavestany et al., 1994; Desmond and Troy, 1998; Paneras et al., 1996). Keeton (1994) also indicated that reducing the fat content to <10% without reformulation using non-meat ingredients often negatively influences the quality of meat products (Lin and Mei, 2000). Other technological problems such as reduction in particle binding, production of a soft mushy interior, rubbery skin formation and excessive purge are also associated with reduced fat levels (Mallika et al., 2009). Based on scientific information, the meat industry and consumers have become aware of the relationship between sodium and hypertension (high blood pressure) and as a result the demand for low salt meat products has increased (Tuomilehto et al., 2001). The new targets (g/100 g) proposed by the Food Standard Agency (FSA) are a maximum of 1.4 g salt for sausages and 1.0 g salt for burger/patties/grill steaks (FSA, 2006). Developing low salt meat products that meet these targets, however, is not straightforward. Salt solubilises the functional myofibrillar proteins within processed meat; this activates the proteins to increase hydration and water-binding capacity, ultimately increasing the binding properties of protein and improving texture (Offer and Knight, 1988). Thus, reducing salt impacts on all of these processes, and can have a detrimental effect on water-binding capacity, texture and flavour (Desmond, 2006; Totosaus and Pérez-Chabela, 2009). There are several approaches for reducing the sodium content in meats. The first approach is simply lowering the level of NaCl. However studies carried out by Hand et al. (1987) have shown that low fat burgers containing 1.5% NaCl had softer consistencies than samples containing 2.0 and 2.5% NaCl. The second approach involves replacing all or part of the NaCl with other chloride salts (KCl, CaCl2 and MgCl2). Terrell and Olson (1981) found that replacement of NaCl with KCl or MgCl2 led to increased bitterness in meat products. The third option is to replace part of the NaCl with non-chloride salts, such as phosphates (Ruusunen and Puolanne, 2005). Whiting (1984) found that reducing the salt while adding phosphate in sausages resulted in improved water-holding properties compared with samples with reduced salt. However, there is increasing concern about the use of phosphate in meat products as there is substantial evidence

© Woodhead Publishing Limited, 2011

248

Processed meats

to suggest that phosphate reduces blood pressure (Kizhakekuttu and Widlansky, 2010). The use of functional ingredients in meat products offers meat processors the opportunity to improve the nutritional and health properties of their products. However, if such ingredients are added at too high a concentration, they can have a negative effect on the quality attributes of the product. For example, García et al. (2002) found that the addition of dietary fibre (3%) to low fat fermented sausages had a negative effect on texture and other sensory attributes and they concluded that further research was required to understand their interaction with the meat product components in order to improve their potential for industrial application. This equally applies to all other types of functional food ingredients and hydrocolloids that are permitted by legislation to be used in meat products.

10.4 Regulation and scrutiny concerning hydrocolloid usage in processed meats The most widely accepted fully international system to regulate the safety of food is the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Clearance of food hydrocolloids by the European Commission was first introduced in 1995 under Directive 95/2/EU for food additives (other than colours and sweeteners). This is known as the Miscellaneous Additives Directive (MAD), which provides usage authorisation for a large number of additives from the hydrocolloid group. An amendment (Directive 98/72/EC) to MAD was introduced in 1972 which affected the status of many hydrocolloids. This directive authorises the use of sodium alginate, potassium alginate, carrageenan, pectin and guar. Each has controlled conditions associated with their approval. Often the desired functional characteristic (e.g. thickening; gelling; adhesive; binding) cannot be achieved by using a native hydrocolloid, e.g. starch. Hydrocolloids may be altered physically, chemically or enzymatically to produce modified versions with improved functional properties. However extraction or modification methods may affect the molecular makeup of the hydrocolloid and consequently, the modified hydrocolloid may have different safety regulations associated with its use and possess a different labelling status. Allergies and intolerances have become very important in food safety during the last few decades. Allergic reactions to foods/food ingredients can generate clinical symptoms ranging from mild urticaria and oral allergy syndrome to life-threatening anaphylactic reactions. For this reason, it is crucial that the food industry take this into consideration when formulating products using hydrocolloids. The foods most commonly causing serious allergic reactions on a worldwide basis are cereals containing gluten, milk, egg, tree nuts, peanuts, soybeans, fish and crustacea.

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

249

Marketing requests for ‘clean label’ formulations are steadily increasing, although no clear legal definition of clean label currently exists. The clean label momentum is driven by the success of retailers like Whole Foods; chef-inspired formulations that use natural ingredients. Food hydrocolloids offer significant functionality to the food scientist, but options are impacted by marketing’s working definition of clean label and perceptions of quality implied by the ingredients used in a formulation (Skarra, 2006). While E numbers are also applicable to natural additives, the overriding consumer perception is that E numbers are undesirable and best avoided. This has led to a trend towards listing the generic name of an ingredient instead of the E number, e.g. guar gum instead of E412. Europe has been at the forefront of clean label initiatives. However, the United States has also begun to drive the agenda for usage of natural additives in food products with the net effect being to drive everyone toward the acceptance and demand for more wholesome, natural, more cleanly formulated and better labelled products.

10.5 Application of hydrocolloids in processed meats Hydrocolloids can control moisture in meats throughout processing, distribution, cooking, holding and consumption. In whole-muscle products hydrocolloid applications are generally directed at attempting to retain moisture and/or improve yield, reduce drip loss, and protect against freeze/ thaw conditions in which the formation of ice crystals can lead to greater weeping and the destruction of the muscle tissue. The hydrocolloid chosen for usage during meat processing is based on the attributes desired in the finished product and processing capabilities, as well as distribution, holding and reconstitution requirements. For example, carrageenan is one of the primary hydrocolloids used by the processed meats industry and is used in the manufacture of comminuted products, but it also works well in reformed meat products when it is injected via the brine during meat pumping. Deciding which hydrocolloid to use can be a complex decision as each hydrocolloid affects product yield, texture and mouthfeel in a slightly different manner and thus would not be interchangeable in meat formulations (Shand et al., 1993). The critical factors that should be considered when choosing a hydrocolloid for application, include: the effects of temperature and shear on the solubility or dispersibility of the hydrocolloid used, the rheological characteristics of the gel formed, and the effect of temperature, concentration, pH and time on the viscosity and gel-forming properties of the hydrocolloid. Compatibility with other ingredients in the formulation need to be assessed also, as does the hydrocolloid’s effect on colour, aroma and taste of the finished product. Mixtures of hydrocolloids are commonly used to impart novel and improved rheological characteristics to meat and food products generally.

© Woodhead Publishing Limited, 2011

250

Processed meats

Classic examples include the addition of locust bean gum to kappa carrageenan to yield soft yet more transparent gels and also the addition of locust bean gum to xanthan gum to induce gel formation. Moreover, hydrocolloid mixture systems tend to be more cost-effective. The cost of a blend is usually less expensive than buying and using individual ingredients. Even with the cost of blending incurred, custom stabilisers are relatively inexpensive. As previously highlighted, choosing the right hydrocolloid is critical to getting the balanced performance required in order to manufacture a processed meat product that is acceptable in terms of its composition, quality, sensorial acceptability, stability and shelf-life. Consequently, there is a requirement to understand the nature and characteristics of the hydrocolloid being considered for formulated use, and from where and how it was derived.

10.5.1 Hydrocolloid proteins of plant origin Soy protein Soy protein is generally regarded as the storage protein held in discrete particles called protein bodies which are estimated to contain at least 60–70% of the total soybean protein. In finely ground meat products soy protein gels to form a matrix entrapping moisture and lipid droplets resulting in improved emulsion stability (Mittal and Usborne, 1985). Sofos and Allen (1977) investigated the effects of replacing lean meat with textured soy protein (TSP) and soy protein isolate (SPI) by 25–50% of raw batter weight in emulsified sausages. They found that hydrated TSP added above 25% resulted in improved emulsion stability. Peng et al. (1982) evaluated interactions between glycinin, a major soy protein and myosin in a model system and concluded that soy proteins act as diluents to interactions among myosin heavy chains. A similar hypothesis was proposed by Matulis et al. (1995) who suggested that soy proteins may reduce the rubbery texture of low fat frankfurters by hindering protein–protein interactions. Rahardjo et al. (1994) found that reduced pork sausages formulated with spray dried soymilk (SDSM) resulted in reduced fat content, increased cooking yield and improved texture. However the use of soy protein in meat products may result in ‘cereal like’ or ‘beany’ off-flavours and discoloration in products if used incorrectly. The use of soy protein in emulsified meat products is also limited by the US Food and Drug Administration (FDA) to 3.5% flour or 2.0% soy protein isolate. Wheat gluten Wheat gluten is a co-product of wheat flour that is used to improve the rheological properties of bread-making properties. Gluten proteins consist of two main groups, gliadins and glutenins in approximately equal proportions. When gliadin is mixed with starch and water a purely viscous material

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

251

is formed. In contrast, glutenin forms a rubbery texture (provided it is above its transition temperature) with low extensibility (MacRitchie and Singh, 2004). Both of these groups attribute to the excellent viscoelastic properties of gluten when hydrated. Xiong et al. (2008) found that the addition of hydrolysed wheat gluten to pork myofibrillar protein isolates resulted in improved emulsifying properties. Ma et al. (1991) found that partial substitution of meat with unmodified or deaminated vital wheat gluten (VWG) (up to 10%) had no effect on cook yield or mechanical properties of meat batters. However, oscillatory tests revealed marked differences in cooking profiles of batters, with a reduction in moduli when meat was partially replaced with VWG (20%). Patana-Anake and Foegeding (1985) also found a decrease in moduli in batters substituted with 12.9% gluten. The reduction in moduli when meat was partially replaced with gluten was attributed to the fact that meat proteins had better emulsifying and binding properties than gluten.

10.5.2 Proteins of animal origin Whey protein Whey protein is a mixture of globular proteins isolated from whey, the liquid material created as a by-product of cheese production. Whey proteins are soluble at any pH and show extensive denaturation at temperatures greater than 70 °C. Whey protein ingredients may be purchased in several forms, the most common of which are whey protein isolate (WPI) and whey protein concentrate (WPC). Morr et al. (1973) proposed that whey proteins could be used in processed meat products to improve their water and fatbinding properties without negatively affecting their sensory attributes. Lee et al. (1980) found that the use of WPC resulted in equal bind, increased juiciness and improved flavour in meat loaf when compared with meat loaf made with non-fat dry milk (NFDM). Other authors have also investigated the effect of adding a combination of WPC and guar gum in reduced fat chicken sausages and found that increasing WPC/guar gum concentration resulted in a more cohesive, less granular matrix (Andres et al., 2006). Whey proteins can bind a considerable amount of water by physical and chemical means, thus preventing moisture loss, improving yields and reducing purge loss in vacuum packed meats. Whey proteins present a strongly folded globular structure. Under the appropriate conditions they unfold and build intermolecular disulphide bonds resulting in a gel matrix which entraps water (Jiménez-Colmenero, 2004).

Caseinates Caseinates are made from lactic or acid casein. Sodium caseinate is the most widely used in processed meats, whereas calcium and potassium caseinates

© Woodhead Publishing Limited, 2011

252

Processed meats

are used when lower sodium formulation is required. The functional ability of caseinates lies in their molecular structure, a unique combination of electric charge and amino acid content, which prevents heat gelation and denatuartion of caseinates in solution (Jiménez-Colmenero, 2004). They are not capable of binding meat pieces together as they do not gel during heating; however, they do increase the gel strength (Jiménez-Colmenero, 2004). Caseinates can be used in three different forms: as a prefabricated caseinate emulsion, in dry powder form at the beginning of the comminution process and as a prefabricated gel (Jiménez-Colmenero, 2004). Kurth and Rogers (1984) found that casein, in addition to transglutaminase in immobilised myosin, had the largest increase in water binding when compared with soy protein or gluten. In this study, casein was shown to be the best substrate for transglutaminase as it had the highest degree of crosslinking with myosin. Gelatin Gelatin is derived from collagen by processes which destroy secondary and higher structures with varying degrees of hydrolysis of the polypeptide backbone (Karim and Bhat, 2008). Collagen, the basic raw material for gelatine production, is the major constituent of all-white fibrous connective tissue in animals, e.g. cartilage, sinews, the transparent sheath surrounding muscles and muscle fibres, skin and the protein matrix of bone (Ledward, 2000). Commercially available sources include: demineralised cattle bone (ossein) and bovine and pig skin. Gelatin has an extraordinary wide field of application in the food industry as it is widely known for its gelling properties, clean flavour profile and clear appearance (Baziwane and Qian, 2003). Gelatin replacement has become a major issue in the food industry in recent years owing to the emerging and lucrative halal and kosher markets. It has also gained increased interest especially within Europe, with the emergence of bovine spongiform encephalopathy (Karim and Bhat, 2008). However, despite its unfashionable status, more gelatin is sold to the food industry than any other gelling agent (Baziwane and Qian, 2003). There are two main type of gelatin. Type A, which has an isoionic point of seven to nine, is derived by using an acid pre-treatment. Type B, with an isoionic point of four to five, is the result of an alkaline pre-treatment. Gelatin is used in meat products such as corn beef and luncheon meat where it is used to retain the meat juices. It is also used in pasteurised canned hams where it is added (in the form of granules or sheets) prior to cooking, so that water released from the meat during cooking dissolves the gelatin, which on cooling, forms a gel that fills spaces caused by cook loss (Ledward, 2000). In the United States, gelatin is generally regarded as safe (GRAS) and it is also approved as a food ingredient by the JEFCA with no limit placed on its use. However, gelatin is an excellent growth medium for most bacteria and attention must be paid to hygiene conditions during

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

253

manufacture using hazard analysis critical control points (HACCP) programmes (Karim and Bhat, 2008). Blood protein Knipe (1988) stated that blood proteins can be used to increase the protein content and water-holding capacity in meat products as plasma protein is a very strong binder on heating. While whole blood protein powders result in improved water binding/emulsion stability in meat products, these blood powders also impart a dark colour to the meat (Duarte et al., 1998). To overcome this problem, plasma and globin proteins were separated from the blood and decolourised, and then when added to sausages resulted in excellent emulsion stability (Tybor et al., 1973). Caldironi and Ockerman (1982) found that plasma proteins showed very acceptable emulsifying properties; however, when added at high levels, they negatively affected the colour of the product (dark colour). In the same study, decolourised globin was added to low fat sausages which reduced emulsion stability. However, as these proteins are known to have high nutritional values, the authors concluded that a mixture of the two types of proteins resulted in the production of a very desirable product. The major limitation for use of these products is presented by labelling issues in the United States.

10.5.3 Carbohydrates of plant origin Carbohydrates, such as starches or gums, can be solubilised or dispersed in water. Polysaccharide gums represent a category of functional ingredients useful for fat replacement in processed foods owing to their ability to provide water control by thickening and/or gelling (Morin et al., 2002). They provide a viscosity and a lubricant mouthfeel that mimics the sensory properties of fat. Use of these ingredients has increased with the development of low fat meat products (Keeton, 1994). Starch Starches are produced from the seeds of plants such as corn, wheat, rice, from tubers, pulses or from roots of plants such as cassava. Starch is a polmer comprising a range of molecular sizes. The basic monomeric unit is d-anhydroglucose. There are two types of polymers present in most starches, amylase and amylopectin. Both of these polymers are made up of anhydoglucose units. They differ in size, the way the monomeric units are linked together and in shape. Amylose is a linear polymer in which all of the anhydroglucose units are linked through 1,4-alpha glucosidic bonds. It may contain anywhere from 200 to 2000 anhydroglucose units with each unit containing one primary and two secondary hydroxyl groups with the exception of the terminal units. Amylopectin has a highly branched structure with each branch consisting of approximately 15–25 anhydroglucose units interconnected by the 1,4-alpha glucosidic bonds. Each branch is connected by

© Woodhead Publishing Limited, 2011

254

Processed meats

linkages containing a hemiacetal aldehyde which links carbon 1 of the anhydroglucose unit at the start of the branch to carbon 6. Investigations carried out by Hughes et al. (1997) found that the addition of tapioca starch (3–6%) in low fat frankfurters resulted in reduced cook losses and increased emulsion stability when compared with the control. Skrede (1989) carried out work on the addition of five types of starch at 4% (potato flour, wheat starch, tapioca, corn flour and modified potato starch) to beef/pork sausages at 15% fat and concluded that potato flour proved to be the best suited for use in sausages in terms of cook loss and firmness with tapioca proving to be the least suitable. Pietrasik and Janz (2010) investigated the effect of pea starch on low fat bologna (10%) and found that the addition of pea starch (4%) considerably improved the textural properties of low fat samples to levels equivalent to regular fat bologna (22%). Combining starch with other non-meat ingredients has also been shown to improve meat product quality parameters. Berry (1997) found that combining modified tapioca and sodium alginate in low fat beef patties (8%) improved tenderness, juiciness and cook yields. Starch food additives are regulated under the terms of MAD (95/2/EC). As a broad class of additive, modified starches (E1404–E1451) have horizontal approval throughout the EU for industrial usage. They may be added to food products following the quantum satis principle (no maximum level indicated). Cellulose Cellulose, the most abundant biopolymer in the world, is found in the cell wall of almost all land plants. Cellulose is composed of two repeating anhydroglucose units joined through 1,4 glucosidic linkages. There are several ranges of modified celluloses that are approved as food additives. Carboxymethyl cellulose is soluble in both hot and cold water, giving a clear, colourless solution with neutral flavour. Manufacturing generates little variation when compared to natural gums. The fact that modified celluloses cannot be labelled ‘natural’ might be a detriment to some food applications. However, synthetic gums offer more than just consistent supply, including numerous particle sizes and viscosities. The EU permitted the use of modified celluloses as food additives rather than colours and sweeteners (Directive 95/2/EC). Investigations carried out found that carboxymethyl cellulose is not as effective in improving texture in sausage products that contain high salt levels. Lin and Keeton (1998) reported that the addition of four types of carboxymethyl cellulose into low fat, high moisture and high protein frankfurters decreased most textural parameters. Use of modified celluloses as additives are permitted for use within the EU, e.g. carboxymethyl cellulose is approved as E466 on the list of permitted emulsifiers. Carrageenan Carrageenan, which is derived from seaweed, is possibly the most widely used binder in low fat meat products (Desmond and Troy, 1998). Carra-

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

255

geenan is a high molecular weight linear polysaccharide comprising repeating galactose units and 3,6-anhydrogalactose (3,6 AG), both sulphated and non-sulfated, joined by alternating α-(1,3) and β-(1,4) glycosidic links. Carrageenans, when used in meat products, serve as processing aids, provide dietary fibre, give specific functional characteristics to the product and can perform more than one of these roles simultaneously (Ayadi et al., 2009). Because of their ability to form gels and retain water, carrageenans are used in the meat industry as textural modifiers, either for gelation or retention of meat juices surrounding meat or liquid contained in the meat (Trius and Sebranek, 1996). The McLean Deluxe is perhaps the most wellknown product example for use of this hydrocolloid (Trius and Sebranek, 1996). The dominant hexose unit of carrageenans are galactose and anhydrogalactose carrageenans. Sulphated polymers of galactose and anhydrogalactose are produced from red seaweeds by extraction (three principal carageenan types or main fractions have been defined: kappa, iota and lambda, which generally differ depending on plant origin). Iota and kappa carrageenans have been used in a wide variety of meat products with considerable success. As a result of the interaction with water through both ionic and hydrogen binding, carrageenans are capable of restructuring water and thus have a high water-binding ability (Labuza and Busk, 1979). Other authors have found carrageenan to be suitable for use as a waterbinding agent in reduced fat hamburgers, reduced fat frankfurters and low salt sausage products (Egbert et al., 1991; Labuza and Busk, 1979). Carrageenan, used along with xanthan gum, was also found to be effective in the binding of water in low fat meat emulsions (Foegeding and Ramsey, 1986; Wallingford and Labuza, 1983). Within the EU, carrageenan is listed in Annex 1 of the European Parliament and Council Directive 95/2/EC on food additives as other than colours and sweeteners (Anon, 1995). Carrageenan is approved as E407 in the list of permitted emulsifier, stabiliser, thickening and gelling agents for use under quantum satis, thereby allowing whatever level is required for usage in order to achieve a technological benefit. Beta glucan Beta (β)-glucan is made up of complex carbohydrate glucose molecules (polysaccharides) which are joined by β bonds linking carbons (1–3/1–6) to other glucose molecules. β-glucans are a major component of starchy endosperm and aleurone cell walls of commercially important cereals, such as oat, barley, rye and wheat (Aleson-Carbonell et al., 2005). β-Glucans from cereals are linear homopolysaccharides of d-glucopyranosyl residues (Glcp) linked via a mixture of β-(1→3) and β-(1→4) linkages, with blocks of consecutive (1→4) residues, i.e. oligomeric, cellulose segments separated by single (1→3) linkages (Lazaridou and Biliaderis, 2007). The potential use of β-glucans as hydrocolloids in the food industry is based mainly on their

© Woodhead Publishing Limited, 2011

256

Processed meats

rheological characteristics, i.e. their gelling capacity and their ability to increase the viscosity of aqueous solutions (Lazaridou and Biliaderis, 2007). Various health benefits are associated with β-glucans, including serum cholesterol lowering effects (Hecker et al., 1998) and blood glucose regulation (Morin et al., 2004; Yokoyama et al., 1997). Despite these findings β-glucan is still underutilised as a functional food ingredient. Barley β-glucan is a non-starchy polysaccharide which shows potential as a fat replacer in meat products owing to its highly viscous nature and its water binding, foam and emulsion stabilising capabilities (Temelli, 1997). Morin et al. (2002) found that reduced fat sausages incorporating barley β-glucan at 0.3% received higher sensory scores than high fat sausages. However, sausages incorporating 0.8% β-glucan were evaluated as being the least acceptable overall. Oat fibre β-glucan can also be used for replacing fat in food products. Oat products have achieved a very positive image as a result of the health benefits associated with fibre products (AlesonCarbonell et al., 2005). In low fat beef patties Pinˇero et al. (2008) found that oat fibre in gel form (Nutrim-10®) at 13.45% enhanced moisture and fat entrapment which resulted in increased cooking yield and tenderness. Konjac glucomannan Konjac glucomannan (KGM) is a polysaccharide extracted from tubers of the devil’s tongue plant (Amorphallus rivier). KGM consists of d-glucose and d-mannose joined by β-1,4 glycosidic linkages with approximately 1 acetyl group in every 19 sugar units (Maekaji, 1978). When konjac flour is dissolved in alkaline coagulant (calcium hydroxide, sodium or potassium carbonate) a thermally stable gel is formed (Thomas, 1997). The strong hydrophilic elastic gel has some of the sensory properties of fat but possessing a reduced calorie content. Work carried out incorporating varying levels of rehydrated KGM gel into reduced fat (10%) pork sausages found that KGM samples had higher cook yields and were rated slightly higher in shear force measurements and slightly lower for juiciness than sausages containing 40% fat (Osburn and Keeton, 1994). Fernández-Martín et al. (2009) found that pork batter mixed with KGM gel resulted in improved emulsion stabilities when compared with the control. The higher water retention in the KGM formulation was attributed to the fact that the premade konjac gel wholly retained its own compositional water without contributing any to the meat matrix during batter emulsification. Galactomannan Locust bean gum and guar gum are high molecular weight galactomannans used by the food industry as food additives. The compounds, although closely related chemically, do not have the same functional properties when used in foods, and the substitution could change the desired qualities of the final product (Bourbon et al., 2010). The analytical discrimination between locust bean gum and guar gum is technically difficult. Both additives are

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

257

high molecular weight galactomannans whose main chain consists of (1→4) linked β-d-mannose residues and the side chain of (1→6) linked α-dgalactose. The galactose : mannose ratio for locust bean gum is 1 : 4, whereas the chemical ratio for guar gum is 1 : 2. Locust bean gum is obtained from carob bean (Ceratonia siliqua), a Mediterranean tree. This gum is soluble in water and does not form a gel. Locust bean gums do not form gels on their own and function by increasing viscosity, with maximum viscosity obtained at 95 °C. Synergistic effects appear when locust bean gum is mixed with other hydrocolloids. Other authors have found that the addition of locust bean gum and xanthan produces a very elastic gel after heating (Dea, 1979; Pedersen, 1980). Both gums are approved food additives with the following E numbers, 410-locust bean gum and 412-guar gum, with a range of both locust bean gum (MeyproFleurTM, MeyprodynTM, PavitinandTM) and guar gum (Meypro-GuarTM, Meyprotin®, Meyprodor) available on the market. Alginate Alginates, the major structural polysaccharide of brown algae (Phaeophyceae), are widely used by the food industry to increase viscosity and function as emulsifiers. They are unbranched copolymers composed of β-dmannuronic acid (M) and α-l-guluronic acid (G) residues linked by (1→4) glycosidic bonds in homopolymer blocks. In the presence of monovalent cations, alginates do not form gels and can be used as thickening agents. However, when in the presence of divalent cations, alginates can form gels (Fernández-Martín et al., 2009). Lin and Keeton (1998) reported relatively stable salt-soluble and water-soluble protein concentrations for low fat (approx 10%) meat emulsions containing sodium alginate when heated at 71 °C. Work carried out by Lin and Mei (2000) found that low fat batters, to which a combination of alginate and carrageenan had been added, showed reduced fat and water loss when compared with controls. Ledward (1994) hypothesised that the interactions occur between the carboxylate groups of the anionic polysaccharides and buried basic protein groups exposed following heat denaturation. These interactions produce more stable complexes than those formed with the native protein molecules (Lin and Mei, 2000). The safety of ammonium, calcium, potassium and sodium alginates was evaluated by the JECFA and they are approved for use in food. In the United States ammonium, calcium, potassium and sodium alginates are included in a list of stabilisers that are GRAS. Pectin Pectin is the name given to water-soluble pectinic acids capable of gel formation. Pectins are high molecular weight heteroploymers consisting mainly of galacturonic acid methyl ester units which are located in the middle lamellae of plant cell walls (Pappa et al., 2000). Pectin is produced from

© Woodhead Publishing Limited, 2011

258

Processed meats

citrus peel, apple pomace, tomato and sugar beet pulp and has been used as a thickener, emulsifier, stabiliser and gelling agent in a variety of food products (Sanderson, 1981). Pectins are characterised by their degree of esterification (DE) and are hence, classified as high methoxyl (HM) or low methoxyl (LM) pectins. Commercial HM pectin has a typical DE of 55–80%. The gelling properties of pectin are dependent on the DE. HM pectins usually gel in the presence of sugar at low pH (Morris, 1998). In contrast, LM pectins may form gels in the presence of calcium ions over a wide pH range and in the presence or absence of sugar (Fu and Rao, 2001). Norsker et al. (2000) investigated the effects of adding sugar beet pectin (2%) to luncheon meat and found that a cohesive gel was formed which bound the meat pieces together, making the product sliceable. It is thought that the gel forms as a result of oxidative cross-linking of ferulic acid in the pectin. Work carried out on low fat frankfurters which incorporated pectin and olive oil, found that pectin levels above 0.5% with oil levels above 30% resulted in low acceptability scores (Pappa et al., 2000). Pectin is generally regarded as one of the safest and most acceptable food additives and this is recognised by advised daily intake (ADI) levels ‘not specified’ by JECFA and by its GRAS status under US legislation.

10.5.4 Carbohydrates of animal origin Chitosan Shellfish waste consisting of crustacean exoskeleton is currently the main source of biomass for chitosan production (Hayes et al., 2008). Chitosan (2-deoxy-2-aminoglucose polymer) is a carbohydrate polymer derived by the deacetylation of chitin. The degree of acetylation of chitosans is generally lower than 0.4 (the degree of acetylation for commercial samples is about 0.2) (No et al., 2007). Chitosan possesses a positive ionic charge, which enables it to bind with negatively charged fats, lipids, cholesterol, metal ions, proteins and macromolecules (Kurt, 2010). Chitosan is insoluble in water and soluble in weak organic acid solutions. However chitosan derivatives in the form of acetate, ascorbate, lactate and malate are water soluble (No and Meyers, 1995). Chitosan can act as a primary emulsifier because it is an amphiphilic polyelectrolyte and as a secondary emulsifier it can increase the continuous phase viscosity (Kurt, 2010). Chitosan emulsions are highly stable to temperature changes and ageing. They are also stable to flocculation and coalescence. In addition chitosan may increase the viscosity of food because it has a gelling property when the pH is greater than the pK value (Kurt, 2010). In the past, chitosan has received increased attention for its commercial applications in the biomedical, chemical and food industries including preservation of food and formation of edible-biodegradable film (Knorr, 1982). Furthermore chitosan has also been shown to exhibit anti-tumour, antiulcer, anti-uricemic and hypocholesterolaemic properties (Koide, 1998; Liu et al., 2008). Kurt (2010) investigated the effect of chitosan on emulsion

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

259

capacity and emulsion stability in beef emulsions and found that the addition of chitosan improved the emulsion properties of beef in the acidic medium (pH 5.5–6.5). Chitosan is widely produced from crab and shrimp shell waste with different deacetylation grades and molecular weights (different viscosities of chitosan solutions with different properties) according to No and Meyers (1995). Chitosan has been approved as an additive in Japan since 1983 (Weiner, 1992). In 2005, shrimp-derived chitosan was submitted to the US FDA to be considered as GRAS.

10.5.5 Microbial hydrocolloids Xanthan Xanthan is an extracellular polysaccharide gum produced by the microorganism Xanthomonas campestris and consists of glucose, mannose and glucuronic acid; it is a strong water-binding agent and texture modifier used in many foods (Shang and Xiong, 2010). The primary structure of xanthan gum is a linear (1→4) linked β-d-glucose backbone with a trisaccharide side chain on every other glucose at C-3. Xanthan gums are soluble in cold water and are highly pseudoplastic (when shear stress is increased, viscosity is reduced). Xanthan gum viscosity has excellent stability over a wide pH and temperature range and it is also resistant to enzymatic degradation. Wallingford and Labuza (1983) reported that xanthan gum was more effective than carrageenan, locust bean gum and low methoxy pectin in preventing water loss from a low fat meat emulsion. Fox et al. (1983) also found that xanthan gum stabilised the texture of frankfurters held in vinegar pickle. Xiong and Blanchard (1993) studied the effect of xanthan gum on the gelation of chicken salt soluble protein (SSP) and found that xanthan gum (0.5%) increased water-holding capacity (WHC), but also hindered gel structure formation and decreased gel strength. It has been hypothesised that because of its strong hydration properties and large molecular size, xanthan, when added to meat, may structurally interfere with the crosslinking required for myofibrillar protein gel network formation (Xiong and Blanchard, 1993; Shang and Xiong, 2010). A synergistic interaction occurs between xanthan gum and galactomannons such as guar gum, locust bean gum and glucomannons such as konjac mannan. This interaction results in enhanced viscosity or gelation. Xanthan gum is recognised as a food additive under the provisions of the US FDA regulations (21 CFT 172.695) for use as a stabiliser, thickener or emulsifier. Xanthan gum is designated by the European Union as E415 with a nonapproved acceptable daily intake (ADI). Keltrol® and Keltrol® F xanthan gums are both approved for Kosher use. Gellan gum Gellan gum is an extracellular polysaccharide secreted by the bacterium Sphingomonas elodea, previously referred to as Pseudomonas elodea. It is

© Woodhead Publishing Limited, 2011

260

Processed meats

a linear, anionic polysaccharide consisting of repeating units of glucose, rhamnose and glucuronic acid. Native gellan gum contains an acyl group on the glucose unit which influences the gel properties of gellan gum. Low acyl gellan gum produces firm, non-elastic, brittle gels and thus, is more commercially available than high acyl gellan gum. Gellan gum has been used as a fat substitute in meat systems with texture and colour similar to full fat samples and acceptable sensory qualities. Duda et al. (1995) reported that the incorporation of gellan gum into comminuted sausages increased production yield and reduced thermal drip (Totosaus and Pérez-Chabela, 2009). Shand et al. (1993) evaluated the effect of adding gellan gum (1.0%) to algin calcium beef rolls and found that cook yields improved with addition of gellan gum. Gellan gum is currently sold commercially in three forms, namely; high acyl, unclarified (KELCOGEL®LT100), low acyl, unclarified (KELCOGEL®LT) and low acyl, clarified (KELCOGEL® and KELCOGEL®F). Gellan was granted full approval in 1992 by the USDA (Anon, 1992) and is also approved by the European Union (JECFA). It appears as E418 in the European Community Directive EC/95/2 with a non-specified ADI. Combinations of high acyl and low acyl gellan gums possess one name. Curdlan Curdlan is an extracellular microbial polysaccharide which was first discovered and investigated by Harada et al. (1968) who coined the name curdlan, derived from ‘curdle’ to describe its gelling behaviour at high temperature. Curdlan is composed entirely of 1,3-β-d-glucosidic linkages, which occur widely in nature and are involved in cell structure and food storage in bacteria, fungi, algae and higher plants. Curdlan is known for its ability to form firm, resilient and thermo-irreversible gels when heated in aqueous suspensions at temperatures of 80 °C or higher and is considered to have a notable potential as a fat mimetic (Hsu and Chung, 2000). Studies carried out by Funami et al. (1998) found that the combined use of curdlan and modified starch functioned as an excellent fat mimetic in non-fat sausages. Curdlan has been approved as a food additive in the United States (Anon, 1996).

10.5.6 Enzymes Transglutaminase Microbial transglutaminase (TGases) (Fig. 10.3) promotes polymerisation of proteins through intermolecular ε-(γ-glutamyl) lysine cross-links and is a highly effective texture-modifying agent for formulated and restructured foods, including processed meat products (Kuraishi et al., 1997; Shang and Xiong, 2010). There are three approaches used to produce TGases. The first is to extract and purify the enzyme from the tissue or body fluids of animals (generally cattle, swine and fish). The second approach is to obtain the enzyme by means of genetic manipulation using a host microorganism, e.g.

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

Gln

NH + H2N TG

261

Lys

in water

NH

+NH3↑

Fig. 10.3 Chemical structure of transglutaminase (www.bioeng.cstm.kyushu-u. ac.jp).

Escherichia coli or Aspergillus. The third approach is to screen for TGase producing microorganisms and mass-produce appropriate quantities of these microorganisms using fermentation technology (Motoki and Seguro, 1998). Studies carried out by Kim et al. (1993) found that TGase derived from guinea pig liver had induced the breakdown of actomyosin in beef. Kim et al. (1993) suggested that the breakdown of actomysoin by TGase may be a viable method for restructuring meat products without freezing or cooking. However, restructuring meat cannot be completed by using TGase alone. Kuraishi et al. (1997) found that adding salt (1.0–0.3%) with MTGase induces solubilisation of myofibrillar proteins. However, in this study the addition of 3% salt, which was required to achieve satisfactory bind, had a negative effect on product taste. Meat cubes in combination with MTGase and other food proteins were also investigated, with MTGase and sodium caseinate (1%) proving to be a better substrate than soy or whey protein (Kuraishi et al., 1997). Ramírez-Suárez and Xiong (2003) found that transglutaminase added to a mixture of myofibrillar/soy protein mixture produced an adhesive mixed protein gel structure with a reduced concentration requirement for extracted myofibrillar proteins. Hong and Chin (2010) studied the addition of transglutaminase and sodium alginate on the coldset gelation of porcine meat and concluded that combining both ingredients, produced cold-set meat products with high moisture and improved textural parameters.

10.5.7 Miscellaneous ingredients Sugars Sugars are carbohydrates consisting of carbon, hydrogen and oxygen, and are used in meat products because of their contribution to flavour, their role in browning during the frying process and also their ability to disguise high levels of salt in a meat product. Sugars can be divided into monosaccharides, disaccharides and oligiosaccharides. Lactose is a disaccharide consisting of d-glucose and d-galactose units. In general, sweeteners are not often used in the production of meat products as sugars are generally not added to meat products to obtain a

© Woodhead Publishing Limited, 2011

262

Processed meats

sweet taste, rather, they are added for the purpose of holding water, rounding off flavour and to a certain degree, to mask a high level of salt or to simply help ‘bulk out’ the product through the increment of total solids. Lactose is used in meat products mainly owing to its compatibility with meat flavour and also in the production of salami (Spricigo and Pianovsky, 2005). Sucrose is frequently used in ham products at levels of between 0.5% and 0.01% to reduce Aw within the product, for its contribution to flavour and to disguise elevated levels of salt (Feiner, 2006). Rich sugar sources such as honey can also be used in order to produce distinctive glazes on processed meat products such as hams in order to improve flavour and create or enhance product appearance. The use of honey, which is viewed as a traditional food product, can also facilitate the marketing of meat products by simply adding value. Maltodextrin Maltodextrins are non-sweet products obtained by starch hydrolysis and consist of β-d-glucose that has a dextrose equivalence of less than 20 (Bemiller and Whistler, 1996). The dextrose equivalence value is a measure of the amount of reducing sugars present, expressed as a percentage of the total dry substance. Maltodextrins are frequently used as bulking agents; however, when used at sufficiently high concentrations, maltodextrins have the ability to bind water, thereby contributing significantly to mouthfeel and meat product viscosity (Lucca and Tepper, 1994). Maltodextrins can also act as a carrier agent, which protects encapsulated ingredients from oxidation (Ahmed et al., 2010). There is ongoing debate as to whether these ingredients should be included in the category of hydrocolloids, but they do play a substantial role in texture formation of meat products.

10.6 Future trends and conclusions The application of hydrocolloids in processed meat products has continued to grow and evolve over the past 20 years. While relatively new challenges such as allergen status, clean labels and GM (genetically modified) issues have arisen in conjunction with their usage and, consequently, have led to dramatic changes in the types and forms of hydrocolloids used in meat processing, the future appears very bright for the continued use of hydrocolloids in processed meats. A review of the literature reveals new low fat/low salt formulations incorporating non-traditional ingredients which are being successfully developed at present. Examples include beef patties with oat fibre as a fat replacer (Piñero et al., 2008), frankfurters with oat fibre and carrageenan (Hughes et al., 1997) and frankfurters with transglutaminase, caseinate, KCl and fibre as an approach to reduce salt (Colmenero et al., 2005). As processors can be overwhelmed by the ever-increasing variety of ingredients available to them (Table 10.1), it is important that the correct

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

E407

–

E425

Iota carrageenan

β-glucan

Konjac gum, glucomannan Locust bean gum Guar gum Sodium alginate Low methoxy pectin

Sodium carboxymethyl cellulose Methy cellulose Xanthan Gellan gum Transglutaminase

E407

Kappa carrageenan

E461 E415 E418 –

E466

E410 E412 E401 E440

–

Potassium casienate

–

WPC

–

–

Soy protein isolate

Sodium casienate

E number

Hydrocolloid

Thickening agent, stabiliser, suspending agent Thickening agent, emulsifier, stabiliser Gelling agent, stabiliser, emulsifier Gelling agent, stabiliser, emulsifier Gelling agent

Thickener, gelling agent, stabiliser, emulsifier Thickener, gelling agent, stabiliser, emulsifier Thickener, gelling agent, stabiliser, emulsifier Gelling agent, thickener, emulsifier, stabiliser Thickener, gelling agent Emulsifier, stabiliser, thickener Thickener Gelling agent, thickener, stabiliser

Emulsifier

Cost, water and fat binding, water solubility at low viscosity (35 protein) β lactoglobule fraction Binder, decolouriser, emulsifier

Gelling agent, stabiliser, emulsifier

Effect

Table 10.1 Application of hydrocolloids in processed meats

Grindstad Products, Inc., Industrial airport, KS Aqusion Co., Wilmington, DE Kelco, San Diego, CA Sanofl Blo Ingredients Germany SLENDID®, TEKNAROM, Instanbul, Turkey Aqusion Co., Wilmington, DE UFL Foods Group Ltd, Edmonton, AB The Dow Chem. Co., Midland, MI, USA Keltrol®, Kelco, San Diego, CA KelcogelTM, Kelco, San Diego, CA Ajinomoto, Barentz, Poland MTGase, Activa TG-TI enzyme, donated by Ajinomoto, Co. Ltd, Japan

Gemfont Co., Ltd., Taipei, Taiwan

(90% protein) Protein international, Zwaanhofweg, Leper, Belgium (75% protein) MD Foods, The Netherlands (35% protein) Dairygold Foods, Mitchelstown, Ireland Dairygold Foods, Mitchelstown, Ireland Chaitanya Biologicals Pvt. Ltd Hanuman Nagar, Malkapur, Buldana, Maharashtra, India Chaitanya Biologicals Pvt. Ltd Hanuman Nagar, Malkapur, Buldana, Maharashtra, India Gelcarin® GP-812NF, FMC International, Philadelphia, USA Gelcarin®, Dangel, FMC Corp, Philadelphia, PA Gelcarin® GP-379NF, Kelco Centennila Foods Inc., Dillon, MT, USA

Manufacturer

264

Processed meats

ingredient is used for a particular application and that these ingredients, when used, are used to their full functional capacity. Considerable work has been carried out on combining hydrocolloids which could decrease the need for more expensive ingredients, while also taking advantage of synergistic effects between them.

10.7 References ahmed, m., akter, m.s. & eun, j.b. (2010) Impact of alpha-amylase and maltodextrin on physicochemical, functional and antioxidant capacity of spray-dried purple sweet potato flour. Journal of the Science of Food and Agriculture, 90, 494–502. aleson-carbonell, l., fernandez-lopez, j., perez-alvarez, j.a. & kuri, v. (2005) Functional and sensory effects of fibre-rich ingredients on breakfast fresh sausages manufacture. Food Science and Technology International, 11, 89–97. andersson, a., andersson, k. & tornberg, e. (2000) A comparison of fat holding between beef burgers and emulsion sausages. Journal of the Science of Food and Agriculture, 80, 555–560. andres, s., zaritzky, n. & califano, a. (2006) The effect of whey protein concentrates and hydrocolloids on the texture and colour characteristics of chicken sausages. International Journal of Food Science and Technology, 41, 954–961. anon (1992) Food additive permitted for direct addition to food for human consumption: Gellan gum. Federal Register, 57, 55444–55445. anon (1995) Commission Directive 95/2/EC Official Journal of the European Communities, L61, 18.3.95, 1. anon (1996) 21 CFR 172 – Food additives permitted for direct addition of food to food for human consumption: Curdlan. Federal Register, 61, 242. ayadi, m.a., kechaou, a., makni, i. & attia, h. (2009) Influence of carrageenan addition on turkey meat sausages properties. Journal of Food Engineering, 93, 278–283. baziwane, d. & qian, h. (2003) Gelatin: the paramount food additive. Food Review International, 19, 423–435. bemiller, j.n. & whistler, r.l. (1996) Carbohydrates. In: Fennema, O.R. (Ed.) Food Chemistry, New York, Marcel Dekker, 157–224. berry, b. (1997) Sodium alginate plus modified tapioca starch improves properties of low-fat beef patties. Journal of Food Science, 62, 1245–1249. boles, j.a. & shand, p.j. (1998) Effects of comminution method and raw binder system in restructured beef. Meat Science, 53, 233–239. bourbon, a.i., pinheiro, a.c., ribeiro, c., miranda, c., maia, j.m., teixeira, j.a. & vicente, a.a. (2010) Characterization of galactomannans extracted from seeds of Gleditsia triacanthos and Sophora japonica through shear and extensional rheology: Comparison with guar gum and locust bean gum. Food Hydrocolloids, 24, 184–192. caldironi, h.a. & ockerman, h.w. (1982) Incorporation of blood proteins into Sausage. Journal of Food Science, 47, 405–408. cavestany, m., jiménez colmenero, f., solas, m.t. & carballo, j. (1994) Incorporation of sardine surimi in Bologna sausage containing different fat levels. Meat Science, 38, 27–37. claus, j.r. & hunt, m.c. (1991) Low-fat, high added-water bologna formulated with texture-modifying ingredients. Journal of Food Science, 56, 643–647. colmenero, f.j., ayo, m.j. & carballo, j. (2005) Physicochemical properties of low sodium frankfurter with added walnut: effect of transglutaminase combined with caseinate, KCl and dietary fibre as salt replacers. Meat Science, 69, 781–788.

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

265

cutter, c.n. (2006) Opportunities for bio-based packaging technologies to improve the qualities and safety of fresh and further processed muscle foods. Meat Science, 74, 131–142. dea, i.c.m. (1979) Interaction of ordered polysaccharides structures. Synergism and freeze thaw phenomena. In: Blanshard, J.M.V & Mitchel, J.R. (Eds). Polysaccharides in Food. London, Butterworth, 229–248. desmond, e. (2006) Reducing salt: a challenge for the meat industry. Meat Science, 74, 188–196. desmond, e.m. & troy, d.j. (1998) Comparative studies of non meat adjuncts used in the manufacture of low-fat beef burger. Journal of Muscle Foods, 9, 221–241. duarte, r.t., carvalho simoes, m.c. & sgarbieri, v.c. (1998) Bovine blood components: fractionation, composition, and nutritive value. Journal of Agricultural and Food Chemistry, 47, 231–236. duda, z., pietrasik, z., ciesilik, d. & tubaj, m. (1995) Gellan gum and carrageenan used as a recipe component of comminuted scalded sausages. In: 41st International Congress on Meat Science and Technology Proceedings, Vol II, 431–432. egbert, w.r., huffman, d.l., chen, c. & dylewski, d.p. (1991) Development of low fat ground beef. Food Technology, 45, 64–73. feiner, g. (2006) Additives: proteins, carbohydrates, fillers and other additives. In: Meat Products Handbook, Cambridge, Woodhead Publishing Limited, 89–139. fernández-martín, f., lópez-lópez, i., cofrade, s. & colmenero, f.j. (2009) Influence of adding sea spaghetti seaweed and replacing the animal fat with olive oil or a konjac gel on pork meat batter gelation. Potential protein/alginate association. Meat Science, 83, 209–217. foegeding, e.a. & ramsey, s.r. (1986) Effect of gums on low-fat meat batters. Journal of Food Science, 51, 33–36. fox, j.r.j.b., ackerman, s.a. & jenkins, r.k. (1983) Effect of anionic gums on the texture of pickled frankfurters. Journal of Food Science, 48, 1031–1035. fsa (2006) Salt reduction targets. available from http://www.food.gov.uk/multimedia/pdfs/salttargetsapril06.pdf. fu, j.t. & rao, m.a. (2001) Rheology and structure development during gelation of low-methoxy pectin gels: the effect of sucrose. Food Hydrocolloids, 15, 93–100. funami, t., yada, h. & nakao, y. (1998) Curdlan properties for application in fat mimetics for meat products. Journal of Food Science, 63, 283–287. garcía, m.l., dominguez, r., galvez, m.d., casas, c. & selgas, m.d. (2002) Utilization of cereal and fruit fibres in low fat dry fermented sausages. Meat Science, 60, 227–236. gerrard, j.a. (2002) Protein–protein cross linking in food: methods, consequences, applications. Trends in Food Science & Technology, 13, 391–399. hand, l.w., hollingsworth, c.a., calkins, c.r. & mandigo a.r.w. (1987) Effects of preblending, reduced fat and salt levels on frankfurter characteristics. Journal of Food Science, 52, 1149–1151. harada, t., misaki, a. & saito, h. (1968) Curdlan: a bacterial gel-forming [beta]-1, 3-glucan. Archives of Biochemistry and Biophysics, 124, 292–298. hayes, m., camey, b., slater, j. & brück, w. (2008) Review, Mining marine shellfish wastes for bioactive molecules: chitin and chitosan – Part A: extraction methods. Journal of Biotechnology, 3, 871–877. hecker, k.d., meier, m.l., newman, r.k. & newman, c.w. (1998) Barley beta-glucan is effective as a hypocholesterolaemic ingredient in foods. Journal of the Science of Food and Agriculture, 77, 179–183. hermansson, a.m. (1986) Water and fat holding. In:, Mitchell, J.R. & Ledward, D.A. (Eds), Functional Properties of Food Macromolecules, London, Elsevier, 273–314.

© Woodhead Publishing Limited, 2011

266

Processed meats

hong, g.p. & chin, k.b. (2010) Effects of microbial transglutaminase and sodium alginate on cold-set gelation of porcine myofibrillar protein with various salt levels. Food Hydrocolloids, 24, 444–451. hsu, s.y. & chung, h.y. (1999) Comparisons of 13 edible gum-hydrate fat substitutes for low fat Kung-wan (an emulsified meatball). Journal of Food Engineering, 40, 279–285. hsu, s.y. & chung, h.y. (2000) Interactions of konjac, agar, curdlan gum, [kappa]carrageenan and reheating treatment in emulsified meatballs. Journal of Food Engineering, 44, 199–204. hughes, e., cofrades, s. & troy, d.j. (1997) Effects of fat level, oat fibre and carrageenan on frankfurters formulated with 5, 12 and 30% fat. Meat Science, 45, 273–281. jiménez-colmenero, f. (2004) Chemistry and physics of comminuted products. Nonmeat proteins. In: Encyclopedia of Meat Sciences. Oxford, Elsevier, 271–278. jiménez-colmenero, f., carballo, j. & cofrades, s. (2001) Healthier meat and meat products: their role as functional foods. Meat Science, 59, 5–13. karim, a.a. & bhat, r. (2008) Gelatin alternatives for the food industry: recent developments, challenges and prospects. Trends in Food Science & Technology, 19, 644–656. keeton, j.t. (1994) Low-fat meat products – technological problems with processing. Meat Science, 36, 261–276. kim, s.-h., carpenter, j.a., lanier, t.c. & wicker, l. (1993) Polymerization of beef actomyosin induced by transglutaminase. Journal of Food Science, 58, 473–474. kizhakekuttu, t.j. & widlansky, m.e. (2010) Natural antioxidants and hypertension: promise and challenges. Cardiovascular Therapeutics, 28, E20–32. knipe, c.l. (1988) Production and use of animal blood and blood proteins for human food. Advanced Meat Research, 5, 147. knorr, d (1982) Functional properties of chitin and chitosan. Journal of Food Science, 47, 593–595. koide, s.s. (1998) Chitin–chitosan: properties, benefits and risks. Nutrition Research, 18, 1091–1101. kuraishi, c., sakamoto, j., yamazaki, k., susa, y., kuhara, c. & soeda, t. (1997) Production of restructured meat using microbial transglutaminase without salt or cooking. Journal of Food Science, 62, 488–490. kurt, s. (2010) Effects of pH and chitosan on beef emulsion properties. International Journal of Food Science and Technology, 45(1), 140–146. kurth, l. & rogers, p.j. (1984) Transglutaminase catalyzed cross-linking of myosin to soya protein, casein and gluten. Journal of Food Science, 49, 573–576. labuza, t.p. & busk, c.g. (1979) An analysis of the water binding in gels. Journal of Food Science, 44, 1379–1385. lazaridou, a. & billiaderis, c.g. (2007) Molecular aspects of cereal [beta]-glucan functionality: physical properties, technological applications and physiological effects. Journal of Cereal Science, 46, 101–118. ledward, d.a. (1994) Protein–polysaccharide interactions. In: N.S. Hettiarachchy & G.R. Ziegler (Eds). Protein Functionality in Food Systems. New York, Marcel Dekker, 225–259. ledward, d.a. (2000) Gelatin. In: G.O. Phillips & P.A. Williams (Eds). Handbook of Hydrocolloids, Cambridge, Woodhead, 67–86. lee, a., cannon, r.y. & huffman, o.l. (1980) Whey protein concentrates in a processed meat loaf. Journal of Food Science, 45, 1278–1279. lin, k.-w. & keeton, j.t. (1998) Textural and physicochemical properties of low-fat, precooked ground beef patties containing carrageenan and sodium alginate. Journal of Food Science, 63, 571–574.

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

267

lin, k.w. & mei, m.y. (2000) Influences of gums, soy protein isolate, and heating temperatures on reduced-fat meat batters in a model system. Journal of Food Science, 65, 48–52. liu, j.n., zhang, j.l. & xia, w.s. (2008) Hypocholesterolaemic effects of different chitosan samples in vitro and in vivo. Food Chemistry, 107, 419–425. lucca, p.a. & tepper, b.j. (1994) Fat replacers and the functionality of fat in foods. Trends in Food Science & Technology, 5, 12–19. ma, c.-y., yiu, s.h. & khanzada, g. (1991) Rheological and structural properties of wiener-type products substituted with vital wheat gluten. Journal of Food Science, 56 (1), 228–233. macritchie, f. & singh, h. (2004) Polymer concepts applied to gluten behaviour in dough. In: D. Lafiandra & R. D’ovidio (Eds). The Gluten Proteins, Gateshead, Athenaeum Press Ltd, 227–230. maekaji, k. (1978) Determination of acidic component of konjac mannan. Agricultural and Biological Chemistry, 42, 177–178. mallika, e.n., prabhakar, k. & reddy, p.m. (2009) Low fat meat products – An overview. Veterinary World, 2, 364–366. matulis, r.j., mckeith, f.k., sutherland, j.w. & brewer, m.s. (1995) Sensory characteristics of frankfurters as affected by salt, fat, soy protein, and carrageenan. Journal of Food Science, 60, 48–54. mittal, g.s. & usbourne, w.r. (1985) Meat emulsion extenders. Food Technology, 39, 121–130. morin, l.a., temelli, f. & mcmullen, l. (2002) Physical and sensory characteristics of reduced-fat breakfast sausages formulated with barley beta-glucan. Journal of Food Science, 67, 2391–2396. morin, l.a., temelli, f. & mcmullen, l. (2004) Interactions between meat proteins and barley (Hordeum spp.) [beta]-glucan within a reduced-fat breakfast sausage system. Meat Science, 68, 419–430. morr, c.v., swenson, p.e. & richter, r.l. (1973) Functional characteristics of whey protein concentrates. Journal of Food Science, 38, 324–330. morris, v.j. (1998) Gelation of polysaccharides. In: S.E. Hill, D.A. Ledward & J.R. Mitchell. Functional Properties of Food Macromolecules Gaithersburg, MD: Aspen Publishers, 143–226. motoki, m. & seguro, k. (1998) Transglutaminase and its use for food processing. Trends in Food Science & Technology, 9, 204–210. no, h.k. & meyers, s.p. (1995) Preparation and characterisation of chitin and chitosan – a review. Journal of Aquatic Food Production Technology, 4 (2), 27– 52. no, h.k., meyers, s.p., prinyawiwatkul, w. & xu, z. (2007) Applications of chitosan for improvement of quality and shelf life of foods: a review. Journal of Food Science, 72 (5), R87–R100. norsker, m., jensen, m. & alder-nissen, j. (2000) Enzymatic gelation of sugar beet pectin in food products. Food Hydrocolloids, 14, 237–243. offer, g. & knight, j. (1988) The structural basis of water-holding in meat. In: R.A. Lawries (Ed.). Developments in Meat Science, vol. 4. New York, Elsevier, 173–243. osburn, w.n. & keeton, j.t. (1994) Konjac flour gel as fat substitute in low-fat prerigor fresh pork sausage. Journal of Food Science, 59, 484–489. paneras, e.d., bloukas, j.g. & papadima, s.n. (1996) Effect of meat source and fat level on processing and quality characteristics of frankfurters. LebensmittelWissenschaft und-Technologie, 29, 507–514. pappa, i.c., bloukas, j.g. & arvanitoyannis, i.s. (2000) Optimization of salt, olive oil and pectin level for low-fat frankfurters produced by replacing pork back fat with olive oil. Meat Science, 56, 81–88.

© Woodhead Publishing Limited, 2011

268

Processed meats

patana-anake, c. & foegeding, e.a. (1985) Rheological and stability transitions in meat batters containing soy protein concentrate and vital wheat gluten. Journal of Food Science, 50, 160–164. pedersen, j.k. (1980) Carrageenan, pectin and xanthan/locust bean gum gels. Trends in their food use. Food Chemistry, 6, 77–88. peng, i.c., dayton, w.r., quass, d.w. & allen, c.e. (1982) Investigations of soybean 11S protein and myosin interaction by solubility, turbidity and titration studies. Journal of Food Science, 47, 1976–1983. pietrasik, z. & janz, j.a.m. (2010) Utilization of pea flour, starch-rich and fiber-rich fractions in low fat bologna. Food Research International, 43, 602–608. pinˇ ero, m.p., parra, k., huerta-leidenz, n., arenas de moreno, l., ferrer, m., araujo, s. & barboza, y. (2008) Effect of oat’s soluble fibre ([beta]-glucan) as a fat replacer on physical, chemical, microbiological and sensory properties of low-fat beef patties. Meat Science, 80, 675–680. rahardjo, r., wilson, l. & sebranek, j.g. (1994) Spray dried soymilk used in reduced fat pork sausage patties. Journal of Food Science, 59, 1286–1290. ramìrez-suàrez, j.c. & xiong, y.l. (2003) Effect of transglutaminase-induced crosslinking on gelation of myofibrillar/soy protein mixtures. Meat Science, 65, 899–907. rogers, p.j. (2001) Manufacturing of reduced-fat, low fat and fat free emulsion sausages. In: Y.H. Hui, W.-K. Nip, R.W. Rodgers and O.A. Young (Eds). Meat Science and Applications. New York, Marcel Dekker. ruusunen, m. & puolanne, e. (2005) Reducing sodium intake from meat products. Meat Science, 70, 531–541. sanderson, g.r. (1981) Polysaccharides in foods. Food Technology, 35, 50–57. schmidt, g.r., mawson, r.f. & siegel, d.g. (1981) Functional properties of a protein matrix in comminuted meat products. Food Technology, 35, 235–257. shand, p.j., sofos, j.n. & schmidt, g.r. (1993) Properties of algin/calcium and salt/ phosphate structured beef rolls with added gums. Journal of Food Science, 58, 1224–1230. shang, y. & xiong, l.y. (2010) Xanthan enhances water binding and gel formation of transglutaminase-treated porcine myofibrillar proteins. Journal of Food Science, 75, E178–E185. skarra, l. (2006) Using gums in “clean label” formulations. www.preparedfoods.com skrede, g. (1989) Comparison of various types of starch when used in meat sausages. Meat Science, 25, 21–36. sofos, j.n. & allen, c.e. (1977) Effects of lean meat source and levels of fat and soy protein on the properties of wiener type products. Journal of Food Science, 42, 875–878. spricigo, c.b. & pianovsky, p.b. (2005) Effect of the use of curing salts and of a starter culture on the sensory and microbiological characteristics of homemade salamis. Brazilian Archives of Biology and Technology, 48, 169–174. temelli, f. (1997) Extraction and functional properties of barley & beta glucan as affected by temperature and pH. Journal of Food Science, 62, 1194–1201. terrell, r. (1983) Reducing the sodium content of processed meats. Food Technology, 37, 66–71. terrell, r. & olson, d.g. (1981) Chloride salts and processed meats: properties sources, mechanism of action, labelling. Proceedings of Meat Industry Research Conference, Arlington, VA, American Meat Institute Foundation, 67–94. thomas, w.r. (1997) Konjac gum. In: A. Imeson (Ed). Thickening and Gelling Agents for Food. London, UK, Blackie Academic & Professional, 169–178. tornberg, e. (2005) Effects of heat on meat proteins – implications on structure and quality of meat products. Meat Science, 70, 453–508.

© Woodhead Publishing Limited, 2011

Utilisation of hydrocolloids in processed meat systems

269

totosaus, a. & pérez-chabela, m.l. (2009) Textural properties and microstructure of low-fat and sodium-reduced meat batters formulated with gellan gum and dicationic salts. LWT – Food Science and Technology, 42, 563–569. trius, a. & sebranek, j.g. (1996) Carrageenans and their use in meat products. Critical Reviews in Food Science and Nutrition, 36, 69–85. tuomilehto, j., jousilahti, p., rastenyte, d., moltchanov, v., tanskanen, a., pietinan, p. & nissinen, a. (2001) Urinary sodium extraction and cardiovascular mortality in Finland: a perspective study. Lancet, 357, 848–851. tybor, p.t., dill, c.w. & landman, w.a. (1973) Effect of decolorisation and lactose incorporation on the emulsification capacity of spray-dried blood protein concentrates. Journal of Food Science, 38, 4–6. wallingford, l. & labuza, t.p. (1983) Evaluation of the water binding properties of food hydrocolloids by physical/chemical methods and in a low fat meat emulsion. Journal of Food Science, 48, 1–5. weiner, m.l. (1992) An overview of the regulatory status and of the safety of chitin and chitosan as food and pharmaceutical ingredients. In: C.J. Brine, P.A. Sandford & J.P. Zikakis (Eds). Advances in Chitin and Chitosan. London, Elsevier, 663–700. whiting, r.c. (1984) Stability and gel strength of frankfurter batters made with reduced NaCl. Journal of Food Science, 49, 1350–1354. xiong, y.l. & blanchard, s.p. (1993) Viscoelastic properties of myofibrillar protein– polysaccharide composite gels. Journal of Food Science, 58, 164–167. xiong, y.l. (2004) Chemical and physical characteristics of meat–protein functionality. In: Encyclopedia of Meat Sciences. Oxford, Elsevier, 218–225. xiong, y.l., kingsley, k.a. & addo, k. (2008) Hydrolysed wheat gluten suppresses transglutaminase-mediated gelation but improves emulsification of pork myofibrillar protein. Meat Science, 80, 535–544. yokoyama, w., hudson, c., knuckles, b., chiu, m.-c.m., sayre, r., turnlund, j. & schneeman, b. (1997) Effect of barley β-glucan in durum wheat pasta on human glycemic response. Cereal Chemistry, 74, 293.

© Woodhead Publishing Limited, 2011

11 Use of cold-set binders in meat systems J. A. Boles, Montana State University, USA

Abstract: Restructuring technologies allow meat processors to use lower valued trim to produce more consistent, higher quality, value-added products. Use of chemically set or cold-set binder technologies further allows companies to market value-added, reduced-salt restructured or formed products in a raw, unfrozen state. Cold-set binders including calcium alginate, transglutaminase and fibrinogen/thrombin systems may be used in unique ways to restructure and improve returns on lower valued muscles, trimmings and smaller lean muscle pieces usually relegated to minced or ground meat. The functionality and acceptability of these products are dependent upon the binder used as well as the starting material. Information in this chapter will address how cold-set binders function, suitable raw materials for restructuring, differences in these binding systems, and methods to manipulate final texture. Key words: alginate, transglutaminase, restructured, fibrinogen, protein binders.

11.1 Introduction Over the years the meat industry has been known as an industry with a very low profit margin. This has led processors to make use of everything within the carcass and has led to such phrases as ‘using everything but the squeal’. Traditionally, consumers have always enjoyed steaks and chops and demand for middle and prime cuts, from which steaks and chops are fabricated (Secrist, 1987) continues to be high. Unfortunately, approximately only 25% of a beef carcass is composed of cuts that are suitable for steaks that can be cooked rapidly with dry heat. The remainder of the carcass is composed of many diverse muscles that vary widely in preparation for optimal eating characteristics. Fabrication of carcasses into retail portions results in the production of smaller or odd pieces. Processors’ are continually searching for better ways to market underutilized cuts and trimmings in ways to increase their overall value and return. One way processors have done this is to produce restructured meat products from these ‘fabrication by-products’.

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

271

The term ‘restructured meat’ is used to generally describe products that are made from multiple pieces of meat and includes many types of meat products. Restructuring can be generally defined as the use of manufacturing steps to create a consumer-ready product that resembles intact muscle, such as a steak, chop or roast, not ground meat (Smith, 1984). Restructuring of meat is an evolving process. The newer trend is to mimic whole muscle cuts in size shape and eating quality using lower valued cuts or trimmings. Increasing interest in products that address consumers’ desire for economical, consumer-ready meat products containing less fat and salt, along with easy and fast preparation methods has propagated the development of alternative binding technologies. This has also led to specialty products using stuffing and other fillings to make convenient meat products (Fig. 11.1). These alternative technologies have developed to allow these items to be handled raw like their whole-muscle counterparts. There are generally two accepted methods for manufacture of restructured steak-like items: traditional salt/phosphate technology or cold-binding (chemical binding) technologies often involving some sort of binding mechanism that can work under refrigeration conditions. In some cases the two are used in combination. In either case, the binding is achieved through the formation of heat-set or chemically set gels (Means and Schmidt, 1987; Payne, 2000). The basics of each method will be discussed in greater detail in their respective sections. Traditional restructured meat products depend upon myofibrillar protein extraction using ionic strength and mechanical action followed by heat-set gelation to maintain the integrity of the portion (Trout and Schmidt, 1986).

Fig. 11.1 Specialty restructured meat product manufactured using sirloin or rump steak and Activa or Pearl Meat F stuffed with spinach, feta cheese stuffing. No strings needed to keep product together.

© Woodhead Publishing Limited, 2011

272

Processed meats

Because the maximum bind for conventional products is not reached until after cooking, salt/phosphate technology limits the marketing of these products to either the precooked or frozen state. Several cold-set binding systems have been developed to meet the demand for restructured and bound meats that can be marketed in the raw, refrigerated state. Some examples of these cold binding systems are blood-based binders (Fibrimex®, FX Technology and Products), microbial enzyme based binders (ActivaTM transglutaminase products, Ajinomoto) and protein/chemical based binders (Pearl Meat Binders, Chiba Flour Mills).

11.2 Meat source The meat source will define the amount of binder used and the amount of prior trimming and processing needed. Tougher cuts may be processed to either remove the connective tissue or physically disrupt the structure through blade tenderization or even grinding. Using binders on high-valued products such as tenderloin can result in reduced portioning losses. As an example, two tenderloins may be bonded in a head to tail fashion, resulting in a tube-shaped log that can be cut into consistent portions. In this method the tails which are normally salvaged for trim value are incorporated into the full portion, maintaining their value. The cold-set binders that are available commercially can be used on any type of meat product including poultry, fish and seafood (Ruiz et al., 1993; Kuraishi et al., 1997; Boles and Shand, 1999; Beltrán-Lugo et al., 2005; Moreno et al., 2008). However local regulations should be checked to determine what can be used in the market and what the label requirements will be. Some minor modifications to procedures are needed to accommodate different characteristics of the raw products. For example, aged beef products are typically more difficult to bind using cold binding systems.

11.2.1 Muscle selection Recent work in alternative beef fabrication methods in the United States has classified individual muscles based on tenderness, flavor and other characteristics (Bovine Myology and Muscle Profiling, http://bovine.unl. edu/bovine3D/eng/index.jsp) to increase the value of traditionally lower valued wholesale cuts. The altered cutting procedures result in new sources of more consistent meat, raw materials that can be used either directly for portioned steak products or as raw material for bonded items. This is especially true for smaller, odd-shaped muscles such as the teres major or petite tender. Researchers have also studied the use of specific muscles or muscle groups in restructured meat products. Ruiz et al. (1993) excised infraspinatus, triceps brachii, biceps brachii and supraspinatus for use in restructured

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

273

meat products. The researchers reported that the infraspinatus and the supraspinatus were the easiest muscls to excise and distinguish because of their location on top of the scapula. Furthermore, consumers did not score restructured steaks differently for tenderness, flavor or overall acceptability from the four muscle groups. Boles and Shand (1999) reported that meat cut had no effect on raw or cooked bind of steaks and sensory scores for texture acceptability were higher for steaks made with clod (primarily infraspinatus and deltoideus muscles) and tri-tip (primarily tensor fasciae latae muscle) than steaks made with chuck tender (primarily supraspinatus muscle), or inside round (primarily semimembranousus and gracilis muscles). Furthermore, Boles and Shand (1999) reported that steaks made from chuck clod were lighter in color than those made from chuck tender or inside round but were not different from steaks made from tri-tip. Ruiz reported that removal of the epimysium along with cutting muscles into 2.5 × 2.5 × 5 cm3 chunks before manufacture of restructured steaks negated any difference in tenderness associated with specific muscles. Recio et al. (1986) also found that intermediate or extensive trimming of muscles found in the chuck clod prior to manufacture of restructured steaks improved overall tenderness and palatability. This indicates that steaks can be made from lower end cuts as long as it is cost effective to remove the heavy connective tissue and the particle sizes are reduced.

11.2.2 Fresh vs. frozen vs. pre-rigor meat Previously frozen meat does not have a detrimental effect on the chemical reactions of cold-set binders. It is important to note that unlike conventionally restructured meat products where meat chunks can still be slightly frozen when processed, cold-set products must be completely thawed before the binder is added to the meat. Excess purge from the meat can interfere with the binders and can often be the source of failed binding. Boles and Shand (1999) reported the use of previously frozen meat had no effect on raw or cooked bind or dimensional changes of restructured steaks. Utilizing previously frozen meat, however, did result in lighter and less red steaks than product made from unfrozen meat. It is therefore feasible to collect high end trimmings from portion cutting operations, vacuum package and freeze these trimmings for later use in the preparation of cold-set bonded products. Pre-rigor meat has many improved functional properties when manufacturing conventionally restructured products such as hams than post-rigor meat. Farouk et al. (2005) reported that restructured rolls bound with alginate or ActivaTM made with pre-rigor meat had higher bind strength than those made from post-rigor meat. Schaake et al. (1993), however, found no difference in raw bind strength of steaks made with either hot- or coldboned meat when utilizing alginate as the binder. Use of pre-rigor meat did impact color. Restructured steaks manufactured with cold-boned meat were redder and darker than steaks manufactured with hot-boned

© Woodhead Publishing Limited, 2011

274

Processed meats

electrically stimulated meat (Schaake et al., 1993). The difference in redness, however, disappeared after allowing steaks to bloom for a longer period of time. This is not unexpected as pre-rigor meat often has a higher pH which can result in slower oxygenation and a slower appearance of bright red color. Schaake et al. (1993) also found that when steaks were manufactured with cold-boned beef (boned and frozen within 120 hours), steaks were scored more tender by the sensory panel compared to steaks made with hot-boned beef.

11.3 Traditional restructured meat products The technology used in manufacture of processed meats and more specifically the use of salt in preservation dates back many centuries. More recent developments have been with phosphates, refined gums, starches and vegetable proteins. In some ways restructuring technology has been around for thousands of years especially when products like sausages are considered. A good example of how restructuring technology evolved to the present was in the manufacture of the boneless ham, or ‘section and formed ham’ as it is sometimes called. The original process involved separating muscles to remove connective tissue and intermuscular fat or seamfat. These muscles were then subjected to protein extraction via salt, phosphate and mechanical action. The muscles were recombined via a form, casing or mold and cooked, causing the protein exudates to heat-set acting to bond the muscles together. The resulting end product was a boneless version of the original which had advantages of allowing use of smaller or by-product muscles to make a traditional product with the added benefits of lighter shipping weights because of bone removal, less plate waste and greater convenience.

11.3.1 Ingredients in conventionally restructured meat products Salt One of the basic ingredients needed for conventional restructured meat products or ‘heat-set’ products is salt. Salt is used to extract myofibrillar proteins to produce a protein exudate that when heated binds muscle pieces together. Salt level is dependent on the final product characteristics: between 0.5 and 1.5% is typically used in uncured restructured products while cured products normally contain 1.5–2.5% salt in the finished product. It is important to use lower levels of salt to reduce lipid oxidation for products stored and sold in the raw state (Gray and Pearson, 1987). Higher levels of salt help improve yields for products that are cooked, packaged and then sold (Trout and Schmidt, 1986; Carballo et al., 2006; Hong et al., 2008). Theno et al. (1978a) reported that the composition of exudates formed to bind meat pieces together was dependent on the salt and phosphate level as well as the length of time mechanical action was applied. Trout and Schmidt

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

275

(1986) reported that increasing the ionic strength and pH of precooked beef rolls produced predictable, additive increases in cook yield and tensile strength of restructured meat products. The maximum cook yields and tensile strength values occurred at sodium chloride concentrations between 1.5 and 2.5%. Salt affects water-binding ability and color of meat. Salt use in restructured products improves water-binding properties (Carballo et al., 2006) as well as reducing purge after frozen storage (Raharjo et al., 1995). One drawback to using salt is it acts as a pro-oxidant and initiates discoloration as well as lipid oxidation. Huffman et al. (1981) reported that as the percent salt in the formulation increased from 0% (control) to 1.5%, thiobarbituric acid (TBA) numbers increased linearly. Phosphates Phosphates are added to restructured meat products to help solubilize meat proteins and increase water-holding capacity, thereby improving bind and yield of the finished product (Offer and Trinick, 1983). Phosphates also contribute to flavor stability in cooked products. Phosphates act as metal chelators that can affect the rate of off-flavor development after cooking (Boles and Parrish, 1990). Lawrence and coworkers (2004), however, reported increased off-flavor intensity when whole beef loins had been enhanced with salt (0.2%) and phosphates (0.4%) and stored for 7 days before analysis. Increased levels of phosphate can result in off-flavor development, especially soapy flavors. Phosphates have also been shown to have metallic flavor components (like the taste of a silver spoon) especially when used near their limit (0.5% in many countries). Seasonings and flavorings One major advantage to conventional restructuring is that seasonings and flavorings can be added along with salt and phosphate. Specific flavor profiles for ‘Greek style’ or ‘Italian style’ are easily incorporated. Whole spices or powdered products can be used. Whole spices result in a visual impact; large pieces of pepper or whole leaves of oregano are easily seen in the product. However, large pieces of seasonings or herbs can interfere with binding between large muscle pieces. As an alternative, oleoresins or aquaresin spice extracts can be used to season restructured products to prevent these binding problems. Flavor enhancers, such as hydrolyzed vegetable protein, autolyzed yeast protein and monosodium glutamate, are sometimes added to increase the intensity of meat flavor. This is very useful in products that have a low salt content and few seasonings.

11.3.2 Mechanical action Mechanical action is extremely important in the manufacture of conventional restructured products. One of the main features of tumbling or mixing

© Woodhead Publishing Limited, 2011

276

Processed meats

is aiding the extraction of protein exudates from muscle fibers to form a natural binding agent. During tumbling of muscle several events occur; meat fibers become distorted, the sarcolemma ruptures, nuclei are released and perimysial spaces fill with soluble protein and fat droplets (Theno et al., 1978a). After prolonged tumbling, the myofibrils separate and meat pieces begin to lose their textural integrity. A partial breakdown of tissue integrity aids bind. Tumbling and mixing of meat increases myosin release, which removes the necessity for an added binder. Even without the addition of non-meat proteins, cook yields are improved by 8–10% or more with efficient mechanical action. Theno et al. (1978a) reported that the composition of the exudates formed during tumbling is dependent on salt and phosphate level as well as the length of time mechanical action is applied.

11.4 Cold-set binders Cold-set binding (non-thermal gelation) has evolved as a way to improve the overall eating quality and preparation methods for more realistic restructured steak-like meat products. This improvement is centered in six areas; product appearance, product flavor, product texture, product preparation, health considerations and costs. In other words, today’s fabricated steak has to look, taste and eat like a steak while being easy to prepare, healthy and be relatively inexpensive. These are not always easy to combine into a single package. The eating experience for an intact steak or chop is very different from that of a salted and precooked item. Flavor is one of the main points of differentiation, with warmed-over flavor (WOF) predominating. Precooked, highly seasoned products can overcome some of the flavor dilemmas but the eating experience is still different. When meat is prepared directly from raw, WOF is eliminated. Traditional salt/phosphate technology also changes the texture into something more like ham than steak. In some cases a very small amount of salt or phosphate is used to improve flavor, and to a lesser extent, cooking yields but formulations must be careful to minimize the effects of these ingredients on finished product color and texture. Visual appearance with specific reference to color is probably the most difficult characteristic to control. After all we typically are starting with a raw material that has been handled and may be a by-product from another operation. Once the ability of the muscle to regenerate muscle color is depleted the color reverts to the metmyoglobin form and color remains unappealing. Lower-fat or consistent fat products are somewhat easier to manufacture using cold binding technologies so long as a suitable raw material can be manufactured. Similarly portion and convenience packaging are easy enough to design and implement. The key comes when a price is put on the product. These items can quickly cost more than their whole muscle

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

277

counterparts and consumers will generally opt for the whole muscle item unless there is some health or convenience aspect of the product they like. There are currently four cold-binding system technologies that have been successfully commercialized: ActivaTM (transglutaminase system), Fibrimex® (blood-based system), (Kelpac, Nutrisweet Kelco) calcium alginate system, and Pearl Meat Binding systems (calcined calcium). While they all have some advantages, none seems to be the perfect solution. The effects of each of the binding systems on key characteristics will be discussed.

11.4.1 Alginate system as a cold-set meat binder When the use of alginates as binders for restructured meats was patented by Colorado State University in 1986, the US market for restructured products was approximately 180 million kilograms. Products manufactured with alginate binders extend the opportunities to add value and create new products that meet consumer needs because they retain their form without requiring a cooking step. The alginate system is composed of three main components: sodium alginate, a calcium source and an acidifier to aid calcium release. When the components of this system are added to a meat product during mixing they slowly gel (Means et al., 1987), resulting in a product that appears and can be handled like whole muscle (Fig. 11.2). The meat/alginate mixture can be shaped via a mold or casing and allowed to react undisturbed for binding to proceed. The finished bound product can then be portioned into its final form. Alginate is a hydrocolloid, or gum, that is derived from several types of brown algae of the class Phaeophyceae (Means and Schmidt, 1987). Alginates are linear polysaccharide molecules composed of d-mannuronic and l-glucuronic acid units. The glucuronic acid has an affinity for divalent cations such as calcium and therefore gels can be formed by providing such cations in aqueous solutions. Alginate gels do not require heating for

Fig. 11.2 Beef roll manufactured using ground meat and alginate binding system.

© Woodhead Publishing Limited, 2011

278

Processed meats

formation, and are typically referred to as either cold-set, chemically set or non-thermal gels. Alginate gels do not ‘melt’ on heating and thus the product remains intact during cooking. A popular way to envision the alginate gel is to imagine an egg carton with the cardboard representing the glucuronic acid and the eggs as calcium ions – the calcium ions interact with the alginate molecule to form the gel (Means and Schmidt, 1987). Similar relationships between meat proteins, calcium and glucuronic acid units have been proposed to explain the bind strength observed in alginate restructured meat products. A slow-release calcium source is a key ingredient in the alginate binder system. Proper distribution, solubility and calcium release rate are essential for successful application of the alginate binding system. Calcium carbonate is generally used in this system because it is relatively inexpensive ingredient and has a low solubility. As a chemically set gel, the alginate reacts instantly with available calcium ions so if the source was completely soluble the gel would set well before the product could be molded or shaped. Since these bonds are irreversible, the bind strength would diminish or fail as the available substrate was exhausted especially if forming was delayed. Trout (1989) reported a high calcium carbonate : alginate ratio was required to reach maximum binding of the meat pieces. Alginate without calcium carbonate showed no binding. Other sources of calcium have been evaluated. Esguerra (1994) found no difference in bind strength of restructured steaks manufactured with alginate and encapsulated calcium lactate or alginate with calcium carbonate and encapsulated lactic acid. Moreno et al. (2008) used calcium chloride for alginate gels and found Warner Bratzler shear force values of steaks restructured with alginate were higher when samples contained 1 g kg−1 CaCl2 than when they contained 10 g kg−1 CaCl2, suggesting to these researchers calcium saturation of the alginate at the lower level. Organic acid, usually lactic acid or glucono-delta lactone (GDL), represents the final component of the alginate binder system. The original research with the alginate process did not include an organic acid and the result was a product which was criticized for an unappealing ‘slippery mouthfeel’ (Means and Schmidt, 1986). High levels of alginate contribute to this characteristic. Commercial producers of the alginate binding system suggest the use of either encapsulated lactic acid or GDL to improve calcium solubility and therefore cohesiveness of restructured product. Means et al. (1987), however, observed no increase in cooked binding with the addition of GDL in the calcium alginate binding system. The proportions of alginate, calcium carbonate and organic acid deserve some consideration. Experiments with various levels have demonstrated that bind strength or cohesiveness of the product is largely dependent on the total amount of binder in the formulation. The tendency is to use more binder to increase bind strength, but this is only partially effective and quickly reaches a point beyond which little improvement in strength is

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

279

observed. Means and Schmidt (1986) observed that high levels of sodium alginate and low calcium carbonate levels were detrimental to cooked bind of restructured steaks. Fortunately, rather small quantities of the binder ingredients are required for successful restructuring in this cold-set binding system. Means and Schmidt (1986) indicated that the optimum sodium alginate concentration was between 0.8 and 1.2% with a calcium carbonate level between 0.144 and 0.216%. High levels of alginate are more likely to result in off-flavors (Means et al., 1987), so these researchers suggested a reduction in alginate to reduce the possibility of off-flavors in the finished product. Other research has utilized lower levels of sodium alginate and obtained favorable bind in the raw state (Esguerra, 1994; Boles and Shand, 1998, 1999). A reasonable starting point for most processors is to utilize 0.6% sodium alginate, 0.6% organic acid and 0.2% calcium carbonate. At least 0.4% sodium alginate is required, but more than 1.0% increases the chances of off-flavors. The range of 0.1–0.3% calcium carbonate is recommended by suppliers. The acid is most variable and depends largely on pH of the raw meat material (preferred to be 5.6–5.8) and should fit in the range of 0.4–1.0%. The combination of alginate binders should total about 1.4– 2.0% of the final product and this compares favorably with concentrations added to conventional restructured meat products. Reaction time is also important for the alginate system because the gel is not formed instantaneously. If the gel forms too quickly, there is no time for stuffing, shaping or otherwise forming the product. Utilization of acidifiers and low soluble calcium sources control the release of calcium to allow time for processing before the product gels. Means and Schmidt (1987) indicated that 2 to 48 hours are necessary for the gel to set in a chilled environment (0 to 5 °C) depending on the solubility of the calcium source. After this period, the bonded meat is durable enough for normal slicing and packaging operations. An alternative is to freeze the restructured meat log and portion via conventional methods (slicing, cleaving, etc.). Color is an important characteristic of any raw meat product. Use of alginate to restructure meat products can influence color. Trout et al. (1989) reported that metmyoglobin concentration was low in restructured steaks containing alginate and at least 0.13% calcium carbonate and was not different from restructured steaks containing salt and phosphate. However, all restructured steaks had higher metmyoglobin concentrations than intact muscle and addition of alginate resulted in a larger percent of the steaks being discolored. Means and Schmidt (1986) also reported discoloration of alginate restructured steaks but the discoloration was less than that observed for salt and phosphate restructured steaks. One important factor to note is particle size reduction increases surface area of meat particles and incorporates oxygen and can influence the color stability. This increased oxidation rate could contribute to the reduced color observed by these researchers.

© Woodhead Publishing Limited, 2011

280

Processed meats

11.4.2 Fibrin/thrombin system as a cold-set meat binder Fibrin/thrombin is a blood-based binding system sold as a two-component system in a liquid frozen form. Originally developed in the Netherlands by Harimex, it is now marketed by both Harimex and FNA Foods in Canada. The preparation consists mostly of fibrinogen, either as a partially purified preparation of fibrinogen containing one of the blood clotting enzymes or as a fibrinogen-enriched blood plasma. The second component of the system is thrombin which functions as the activation portion. The idea for the product came from the blood clotting process. Blood clotting is a complex process that basically ends in the enzymatic conversion of fibrinogen to fibrin by thrombin (see Fig. 11.3). Once released the fibrin then aggregates. Inherent to the system, transglutaminase, is also activated by thrombin and converts the fibrin aggregate to an insoluble gel by forming covalent cross-links between the fibrin aggregate molecules. Although the preferred reaction is between fibrin molecules cross-links between fibrin and fibronectin and between fibrin and collagen also form thus binding meat particles together. The fibrinogen and thrombin used in restructured meat products come mostly from beef sources. In more recent years similar systems have been developed from porcine sources as the concern over bovine spongiform encephalopathy (BSE) has arisen as well as utilizing blood from young animals (under 30 months of age) to manufacture the binder. The United States has not changed the approval of Fibrimex for use as a raw meat binder but the EU Directive on Food Additives approval of using bloodbased binders in meat products was rescinded in 2010. The Parliament Thrombin Fibrinogen

Fibrin (monomer)

Aggregation

Fibrin (aggregate) Cross-linking Thrombin Transglutaminate Transglutaminase (inactive) (inactive) Fibrin (insoluble gel)

Collagen (meat) Fibronectin

Cross-linking

Binding of gel and meat

Fig. 11.3 Fibrimex binding based on the blood clotting cascade.

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

281

believed there was a clear risk that meat containing thrombin could be substituted for higher priced product in restaurants or other public establishments. When manufacturing product, the fibrinogen and thrombin are thawed and the thrombin is added to the fibrinogen. Attention must be given to the temperature of the solutions. It is important that both liquids reach 26.6 °C (80 °F) before being added to the meat. The mixture is then added to the meat pieces and mixed well. The product is molded as desired and left to react. Some pressure is necessary to make sure there is intimate contact between the fibrin/thrombin binding system and the meat pieces and to remove any air pockets. Once set, the product can be taken out of the mold and distributed to the market. It should be noted that the product must be molded very quickly once the thrombin is added, as cross-linking begins immediately once the components are combined. It typically has a window of handling that lasts approximately 10–15 minutes depending on temperature and concentration of ingredients. The speed and strength of bind are dependent on the thrombin concentration and therefore a level of thrombin has to be carefully chosen which addresses both constraints. Changes in thrombin and fibrinogen ratio as well as temperature and pH of the meat can alter the time available for forming. Wijngaards and Paardekooper (1987) reported that 5 hours was the minimum amount of time needed to attain maximum gel strength. Concentration of fibrin largely determines the strength of the final fibrin gel and the overall gel to meat-surface binding (Wijngaards and Paardekooper, 1987). This is limited by the solubility of fibrin. Increasing concentrations of fibrin result in an almost linear increase in gel to meatsurface binding (Wijngaards and Paardekooper, 1987). Fibrin/thrombin component is typically used at a concentration between 5–10% of the meat weight, and the fibrinogen to thrombin ratio is 10 : 1 or 20 : 1. The amount of fibrin/thrombin used depends on the quality of the meat to be bound, as well as meat particle size. For example, if the meat pieces are between 0.5 and 1.0 kg in size then 250 g of fibrin/thrombin are needed per 10 kg (or 2.5%). However, if the meat pieces are 5 to 10 g in size, 1 kg of fibrin/ thrombin is needed per 10 kg (or 10%). Increased particle surface area results in the need for more fibrin/thrombin to coat the particles. Tseng et al. (2006) showed that addition of increased binding solution, 0–20% of meat weight (0.5 transglutaminase : 1 thrombin : 20 fibrinogen v/v/v) resulted in increased shear values of bound product. Furthermore these researchers reported total sensory acceptability increased as the level of binder solution to meat ratio increased. The binding strength of the fibrin-to-fibrin gel is always stronger than that of the fibrin-to-meat surface binding. However, fibrin gels bind more strongly to meats with higher collagen concentrations. The strength of the bonds between meat pieces is also affected by the direction/orientation of the muscle fibers. This relates to the involvement of collagen in the binding

© Woodhead Publishing Limited, 2011

282

Processed meats

process. Wijngaards and Paardekooper (1987) reported a doubling in bind strength when muscle fibers ran parallel to the binding area than when the fibers ran perpendicular.

11.4.3 Transglutaminase enzymes as cold-set meat binders Transglutaminases (TGase) are a wide class of enzymes shown to have the ability to cross-link proteins, peptides, and some other primary amines (Payne, 2000). TGase have been isolated from guinea pig liver, blood (factor XIII), plants, mollusks, bacteria and other diverse places. The basic difference between most of these sources is in the specificity for a substrate and the calcium requirement for activation. Typically, sources of TGase originating in microorganisms are calcium independent while those from animal sources are calcium dependent (Payne, 2000). TGase can be obtained from animal tissues and microbes (Nielsen, 1995). Mammalian TGase has been obtained from tissues such as liver, hair follicles of guinea pigs, pig plasma and fish. Sources of commercial mammalian TGases originate from liver and blood. However, TGase obtained from tissue has limited use in industry because of the complicated separation and purification procedures, resulting in a high supply cost (Kuraishi et al., 1996). The extracelluar microbial TGases are purified from Streptoverticillium sp. primarily Streptoverticillium mobarense, while intracellular microbial TGases are derived from Bacillus subtilis (Ando et al., 1989; Zhu et al., 1995; Tsi et al., 1996). Commercial microbial TGases can be mass produced by aerobic fermentation procedures. In addition, the purification process for microbial TGase is simpler and relatively cheaper than for mammalian TGase. A remarkable characteristic of the microbial TGase enzyme is its calcium-independent catalytic property (Kuraishi et al., 1997). Microbial TGase is stable between pH 5 to 9 (Kuraishi et al., 1996). However, even at pH 4 or 9, some enzymatic activity is expressed (Motoki and Seguro, 1998). Microbial sources of TGases are active over the temperature range about 0–60 °C with an optimal activity around 50–55 °C (Motoki and Seguro, 1998). Microbial TGases have been used in patented meat products for more than 10 years (Japan patent 2079956; Nielsen, 1995). One commercial version is sold under the trade name ActivaTM as a preparation containing TGase in combination with a protein source with or without other ingredients. It is marketed under various codes based on the local regulations and the approved ingredients in the particular country. It is typically used either as a liquid slurry or as powder used to dust the surfaces to be joined. ActivaTM TG-RM, TG-EB, and TG-B-solution type are milk protein-based while ActivaTM GS is gelatin-based dusting. ActivaTM TG-RM, TG-EB and TG-Bsprinkle-type (among others) are generally used for powder coating applications while ActivaTM TG-GS and TG-B-solution type are generally slurried with water just before adding to the meat during processing. Many

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

283

commercial blends of transglutaminase contain milk proteins and thus require labeling for the existence of an allergen. TGase is an enzyme that catalyzes an acyl-transfer between the γ-carboxyamide groups of glutamine residues in proteins or peptides with various primary amino groups. When the ε-amino group of lysine residues in proteins acts as an acyl-acceptor, both intra- and inter-molecular ε-(γglutamyl)lysine cross-links are formed (Kuraishi et al., 1997). TGase can cross-link most food proteins including legume globulins, wheat gluten, egg proteins, actin, myosin and milk caseins (Motoki and Seguro, 1998) to varying degrees. Enzymes from mammalian sources require calcium ions to express enzyme activity while the activity of bacterial sources is independent of calcium concentration (Motoki and Seguro, 1998). Heavy metals such as copper, zinc and lead significantly inhibit TGase activity (Motoki and Seguro, 1998). A critical concentration of the ε-(γ-Glutamyl) lysine cross-links is required before sufficient gel strength is reached (Kilic, 2003). Cross-linking is a function of the amount of enzyme added, protein type and content, and reaction time, temperature and pH. Intermolecular cross-links are more desirable than intramolecular cross-links, which tend to decrease gel strength (Nielsen, 1995). The breaking force of gels has been reported to increase with increasing TGase levels regardless of setting conditions (Tammatinna et al., 2007). Dimitrakopoulou et al. (2005) found that TGase enzyme level significantly affected the consistency and the overall acceptability of restructured cooked pork shoulder. Vácha et al. (2006) reported lowest raw hardness was observed when 0.5% TGase enzyme was used alone while best results were seen when 1% TGase enzyme and 1% salt were used to bind fish. Because TGase is active on soluble protein, ingredients such as salt and phopshate increase the binding strength as they extract soluble meat proteins this contributes to the overall binding matrix. As stated earlier, the meat-binding TGase products are generally used in one of two ways, as a liquid application or as a powder application. The type and volumes of raw material involved dictate the levels of TGase product required and generally increase as the surface area of the meat increases. These preparations can generally be used on red meat, poultry and seafood processed products but it is always best to follow the recommendations of the manufacturer as the preparations continue to evolve. When used in the dry form, the powder is either sprinkled on the surface of the meat or the surface is dipped in the powder. The two powdered surfaces are then placed together and pressure applied by vacuum packaging, stuffing into a casing or other method and the product stored at refrigerated temperatures to allow for bind formation. Stretch wrap can also be used to apply the pressure so long as the surfaces are not separated by air bubbles. The product is then refrigerated for 4–24 hours to allow the chemical reaction to occur. The dry powder may also be adapted to current processing equipment by simply adding it to the meat product during tumbling

© Woodhead Publishing Limited, 2011

284

Processed meats

or mixing. Care must be taken to form the product quickly before the reaction is complete, especially in the case of large batch sizes. The slurry product is used when particles are smaller or when specific or rough surfaces need to be coated. The slurry aids in even dispersion of the TGase product over the meat surface. Typically the meat is prepared for binding, then the powder is mixed with water to create a slurry and the slurry mixed into the meat. The meat mixture is then formed into a roll with a mold or casing. The product is refrigerated for 4–24 hours to allow the chemical reaction. Products can then be sliced into steaks or cubes and sold. Newer preparations have been developed that allow the enzyme activity in slurries to be suspended until the slurry comes in contact with the surface of the meat. This has made processing much easier to control and allows more effective use of the bonding agent. TGase binding results from cross-linking of myosin and actin (TéllezLuis et al., 2002; Ramirez-Suarez and Xiong, 2003; Katayama et al., 2006; Tammatinna et al., 2007). Kilic (2003) determined that the use of sodium caseinate in combination with TGase resulted in stronger binding than when TGase was used alone. Commercial blends sometime contain TGase in combination with other ingredients that help maximize the effectiveness of the compound for a specific application. While TGase has been found to be an effective binding agent, it has also been used to improve texture or mechanical properties of products that contain soluble proteins for reaction substrates as would be the case with a sausage TGase. Kolle and Savell (2003) reported that consumers indicated fat-reduced and bonded ribeye steaks (seam fat was removed and then the seams resealed using ActivaTM as a bonding agent) were leaner than control steaks, allowing the consumer to purchase a cut with lower fat that would result in less waste on the plate after cooking.

11.4.4 Protein compounds as cold-set meat binders Protein cold-set binders are a range of products that have been produced in Japan for many years and used in vast quantities in the Asian market, with particularly large usage in Taiwan and Korea, and more recently in the European Community, Australia and New Zealand. Chiba Flour Mills was one of the first to manufacture this type of binder but other companies have developed similar products that are currently being marketed in other countries. Chiba offers three products: Pearl Meat F, Pearl Meat MX-30 and Pearl Meat T. Pearl Meat F has proven to be a very effective binder for large muscle pieces. It works extremely well for producing stuffed rolled roasts or combining two striploins, or tenderloins to give a consistent product size throughout the cut. Pearl Meat F can also be used to keep vegetables inside products to be used on skewers with a few modifications. Pearl Meat MX-30 was developed to use on comminuted product. It is made into a solution and mixed into the meat with either a

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

285

mixer or tumbler. Pearl Meat MX-30 has not been well accepted outside of Asia because it imparts an ammonia-like flavor to the product. Pearl Meat T is used for binding vegetables. Pearl binders and their competitors are made from a large array of proteins. They contain egg white, casein, lactalbumin, gelatin, hydrolyzed egg white, hydrolyzed casein, soy protein and hydrolyzed soy protein. This complex blend of proteins may contain allergens and it is important to know the ingredients of the protein binder to properly label the product for the existence of any allergens. The product also contains a large proportion of ash, mostly from calcium carbonate (ox bone and oyster shell). The reaction is not well understood but probably involves surface protein denaturation (oxidation) and possibly a form of calcium cross-linking. In at least some cases, ammonia is evolved during the reaction of these compounds (Payne, 2000). Pearl Meat F and Pearl Meat MX-30 are two commercial products that are used on meat pieces of different sizes. Pearl Meat F is sprinkled on meat surfaces that are going to be in contact with each other. The minimum amount to achieve bind should be used to prevent large ‘seams’ of binder to be seen. Pressure is then applied by either stretch wrap or vacuum packaging and the product stored at refrigerated temperatures to allow for binding. Esguerra (1994) reported large muscle pieces restructured with Pearl Meat F were most like intact steaks compared with restructured steaks made with other cold-set binders. Furthermore, meat can be marinated and then bound with Pearl F without changing handling procedures from what is expected with whole muscle product (Esguerra, 1994). Pearl Meat MX-30 is made into a slurry and then added to comminuted meat. Mechanical action helps to distribute the binding compound and products are placed in moulds or casings and stored refrigerated to all bind formation.

11.5

Particle size reduction

In the preparation of any type of restructured product, it is important to realize that the meat source greatly influences the end-product characteristics. High amounts of connective tissue in the starting material require some treatment to soften (enzymes, injection, mechanical tenderization), remove or break-up connective tissue. In the case of tenderizing enzymes, these treatments can be antagonistic to the cold-binding systems as they would also dissolve the protein matrix binding the products. Using cuts from muscles identified as being more tender such as rump and loin trim allows the use of larger pieces of meat with little or no treatment for connective tissue. Lennon et al. (2006) reported enhancement of muscle pieces by injection improved tenderness of large meat pieces used in restructured beef products with no detrimental effects on bind of meat pieces when ActivaTM was used as the binder.

© Woodhead Publishing Limited, 2011

286

Processed meats

Reported research has shown that sensory panelist’s rate restructured steaks made from larger particle sizes to be more like whole muscle products (Berry et al., 1987). Different shapes that are created by different size reduction methods can alter the texture of the restructured products. Raharjo et al. (1995) reported restructured steaks manufactured with ‘fiberized’ meat (1.5 × 1.5 × 10–20 cm3 pieces) resulted in a more desirable steaklike texture when evaluated by a trained sensory panel. Additionally, these researchers suggested the use of combined types of particle pieces to improve tenderness of restructured steaks while maintaining acceptable texture. Other research suggests that consumer panelists prefer restructured products made from ground meat to products made with flaked or sliced meat (Boles and Shand, 1998). Particle size changes the visual impact of the restructured product. Marriott et al. (1987) reported particle size of restructured chops had no effect on the resemblance of these samples to whole muscle cuts; however, none of the samples compared looked like whole muscle cuts. Furthermore, restructured chops manufactured from larger flake particles were less tender and contained more connective tissue than those samples made from smaller particles. Some researchers have reported size of meat pieces had no affect on juiciness of the restructured product (Marriott et al., 1987; Raharjo et al., 1995). Boles and Shand (1998), however, found juiciness of steakettes made from flaked meat was liked less by consumer panelists than steakettes made from ground meat. These researchers reported no sensory panel preference for texture between the different methods (ground, sliced, flaked) of size reduction. Overall acceptability of restructured steakettes, however, tended to be higher for steakettes made from ground meat. Restructured products are often made using meat particles of varying size and random orientation. Because the meat fibers are oriented in no set direction, upon cooking the steaks can shrink in unusual directions, causing dimensional changes and cook yields to be affected. Berry et al. (1987) found distortion of steaks was greater when a combination of large and small particle sizes were used to manufacture conventionally restructured steaks. Sen and Karim (2003) found more steak distortion when smaller particles were used to manufacture mutton steaks, while Boles and Shand (1998) found no difference in diameter or thickness change of steaks when comparing type of machine used for particle size reduction and opening size used for particle size reduction. One problem with using sliced meat or large pieces is that connective tissue and any fat on the meat is present in the product as large chunks (Marriott et al., 1987). Berry et al. (1987) reported that as flake size increased, visually detected fibrousness, first bite hardness, cohesiveness of the chewed mass, number of chews required for swallowing, amount of connective tissue detected by sensory panel and shear force all increased, while uniformity of the chewed mass decreased. However, removing all fat can result in a product that does not stand up to the rigors of holding ovens used in

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

287

food service establishments. One way to address this problem is to use two types of meat. One would be fully trimmed with no external fat or connective tissue and the other would have a higher fat content. The lean meat can be cubed or ground through a kidney plate while the fat meat could be ground through a 3–5 mm plate. The combination of these two meats gives a raw appearance of marbled meat, but it is very consistent because the product is formulated to have a specific fat content. Many different methods of size reduction have been used. Manual cubing of the product is the simplest but most labor intensive. Grinders, flakers, cubers and slicers can also be used to reduce the particle size and increase uniformity of particles. When using the different types of cold-set binders it is important to note that the different binders act differently to different particle sizes and shapes. For example, Boles and Shand (1998) reported when using the alginate system, flaked particles resulted in a stronger bind of cooked product than sliced or ground (Fig. 11.4). Fibrimex had a stronger bind in cooked product with larger pieces (8 mm), while alginate bind between meat pieces increased as the particle size got smaller (Fig. 11.5) (Boles and Shand, 1989). When reducing particle size heat is generated when the meat is pushed through the plates or blades. To maintain color and minimize microbial growth, the meat should be kept as cold as possible. The knives on grinders and flakers should also be kept sharp to give clean cuts, and to prevent fat smearing during processing. This can be a real problem when finely ground fat raw materials are used to mimic marbling, especially if the product is too warm or is over mixed.

28 ab 23.9

26 24 Bind (N)

22

a 25.6

Slicer Grinder Flaker

b 21.4

bc 20.6

cd 17.5

20 18

d 17.1

16 14 12 10 Alginate

Fibrimex

Fig. 11.4 Effect of binder and method of size reduction on the bind of cooked restructured beef steakettes. Bars with different letters differ significantly (p < 0.05) (Boles and Shand, 1998).

© Woodhead Publishing Limited, 2011

288

Processed meats 2 mm 4 mm 8 mm

28 26 24

a 24.6

ab abc 22.9 22.5

Bind (N)

22 20

d 16.8

18

bcd cd 20.4 18.8

16 14 12 10 Alginate

Fibrimex

Fig. 11.5 Effect of method of size reduction and size of machine opening on the bind of cooked restructured beef steakettes. Bars with different letters differ significantly (p < 0.05) (Boles and Shand 1998).

11.6 Binder comparisons The main cold-set binders that have been compared are calcium alginate, ActivaTM or microbial TGase enzymes and Fibrimex or fibrin\thrombin binders. The strength of raw bind varies greatly among the binders. Raw Fibrimex samples are relatively fragile when compared with ActivaTM or alginate bound product (Esguerra, 1994; Boles and Shand, 1998, 1999; Farouk et al., 2005; Flores et al., 2007). Alginate and ActivaTM have similar raw bind strength, with the major difference being the visual appearance of alginate pockets seen in the alginate restructured product and smooth surface where alginate gel fills in the holes. Cook bind values are similar when comparing alginate and Fibrimex bound product. Flores et al. (2007) reported that TGase treatments had the highest raw and cooked bind compared with conventionally prepared controls and Fibrimex bound product. Beltrán-Lugo et al. (2005) found that bind of product restructured with TGase or Fibrimex was different in two different species of scallops. Improved firmness and springiness were observed when product was restructured using TGase enzymes but interestingly the species of scallop used altered the texture of the finished product. Boles and Shand (1998) reported cook bind of alginate restructured steaks was not greatly affected by size of particles used, however, steaks made with Fibrimex showed that the largest particle size had similar bind to alginate bound steaks. Addition of Fibrimex to products containing smaller particle sizes resulted in lower cook bind. This suggests that the alteration in binder concentration or ratio of thrombin to fibrinogen is an important recipe consideration to achieve similar bind strengths when particle sizes change. Color is the first impression consumers use to buy products. Particle size reduction methods often result in product with lower color stability than

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

289

that seen in whole muscle meats. Because of the different visual impact of restructured steaks (Marriott et al., 1987), it is important binders do not influence the color. Farouk et al. (2005) observed raw slices from alginate bound product were darker than those steaks made with AcitvaTM and slices bound with ActivaTM were more red and more yellow (higher Hunter a* and b* values, respectively) than slices bound with alginate. Furthermore, sensory panels found that raw slices bound with ActivaTM had better color and overall appearance than those restructured using alginates. Boles and Shand (1999) reported color change over display time was not different with the various binders tested. (alginates and Fibrimex). Steaks made with Fibrimex were generally more red and more yellow than those made with alginates. Binders can influence dimensional changes as well as cook yields of cooked restructured products. Boles and Shand (1999) reported steaks made with Fibrimex had greater dimensional changes than those made with alginate. Comparison of restructured pork chops made with Fibrimex or ActivaTM showed the least dimensional changes when chops were bound with TGase enzymes (Flores et al., 2007). Cook yields have been reported to be higher for alginate and TGase restructured products than for those made with Fibrimex (Boles and Shand, 1998; Flores et al., 2007) and alginate restructured product had higher cook yields than TGase restructured product (Farouk et al., 2005). Addition of added liquid in the Fibrimex process may explain some of the differences seen in the cook yield. Mixed results have been reported for sensory evaluation of restructured meat products. Many of the differences are due to different panel types and different attributes evaluated. Farouk et al. (2005) reported cooked alginate structured rolls to be more tender and less chewy than rolls restructured with ActivaTM. Flores et al. (2007) found consumer comments on texture were mostly favorable for TGase restructured chops; however, some panelists noted a ‘rubbery’ or ‘spongy’ texture. There was a distinct flavor preference for the treatments bound with TGase over the treatments bound with Fibrimex. Boles and Shand (1999) saw no difference in acceptability of flavor, juiciness, texture and overall acceptability when alginate restructured product was compared with Fibrimex restructured product. However, when Fibrimex was used with different meat cuts to manufacture steaks consumer panelists did find a difference in acceptability. Steaks manufactured from chuck clod and tri-tip were more acceptable than steaks made from the chuck tender.

11.7 Advantages of restructuring • Increased market value. Restructuring transforms relatively low value cuts into added value products which lead to increased profit for the

© Woodhead Publishing Limited, 2011

290

•

•

•

•

•

Processed meats

manufacturer, as well as, savings for the consumer who can buy highvalue meat products at a lower cost. Restructuring helps to maintain some of the value of trimmings from higher valued cuts that would normally be ground into products, yielding a salvage value for this premium raw material. New products and uses. In addition to the fabrication of steaks, chops and cutlets, restructured meats can be formed into cubes, sticks, nuggets, etc., of practically any shape and size desired. Portion control. Restructuring allows production of portion controlled steaks, chops and other products. This technology allows higher precision through control of exact portion dimensions than has ever been possible with natural products. Portion control is very important from a foodservice point of view (Smith, 1984) for controlling costs. Control of composition and consistency. The amount of fat and other ingredients in the product can be controlled to meet consumer demands. Intermuscular fat can be removed and the product bound back together to an extent that it resembles the natural whole muscle product. Similarly small fat particles can be dispersed throughout a product mimicking marbling and improving palatability of some cuts. Tenderizing technologies (needle tenderization, particle reduction) may also be used to ensure that restructured products are consistently tender and always a positive eating experience. Consumer convenience. Restructured meats require little preparation time and effort. Portion sizes may also be tailored for today’s smaller households and single parent families. Improved food safety. Unlike whole muscle products where bacterial contamination is limited to the product surfaces, restructuring processes distribute bacteria on surfaces that may be in the center of the meat product. However, these products can be manufactured with more precise dimensions thus ensuring uniform cooking, resulting in more effective pasteurization.

11.8 Advantages of cold-set binding • Cold-set products can be marketed in the raw, chilled state. Some consumers prefer to buy raw, chilled meat and meat products rather than frozen or cooked products based on quality and price considerations respectively. Fresh products also aid in meal planning and speed of preparation as no thawing is necessary. • Use of sodium chloride or phosphate is not required. The detrimental effects of sodium chloride on oxidation-mediated rancidity and discoloration (Gray and Pearson, 1987) in refrigerated unfrozen restructured products can be avoided (Hunt and Kropf, 1987). Consumer health concerns regarding the use of salt and phosphates can also be alleviated (Means and Schmidt, 1987).

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

291

• Versatility of the product. Cold-set products can be cooked and used in various ways similar to fresh cuts of meat. Specialty items, such as stuffed rolls and bound meats can be easily produced without the use of string or netting. • No need for special equipment. The simplest use of some of the cold set binders is to sprinkle the dry powder on the meat and put the two sides together with in the presence of some pressure. Other liquid systems are also easily administered via surface brushing or spraying the products to be joined. The pressure can be applied by something as simple as overwrap or vacuum packaging to something as complex as a springloaded mould. • Enhanced flavor. Because the meat product can be cooked from fresh there is an elimination of WOF.

11.9 Restructured meat products quality control When using restructuring systems, quality control regimes are critical to set up and follow. Careful formulation and ingredient control as well as selection of raw meat materials for optimum color, flavor, composition and connective tissue content are critical to making a desirable and consistent finished product. Evaluation of the texture or cohesiveness of the uncooked product is essential for demonstrating one of the key benefits of the cold-set binding system, namely that the gel allows retention of form without requiring cooking or freezing. Many problems can be avoided by considering the type of product being manufactured. A chemical process is taking place to bind meat pieces together, so anything that might change the chemical process is a potential problem. Temperature is an obvious factor that affects all chemical reactions. Warmer temperatures result in faster chemical reactions which can alter the finished product. Each binding system has optimal conditions for product manufacture and should be followed for optimal performance. In many cases manufacturers of these binding systems have several versions which may or may not work with a particular system. It is always a good idea to consult with the supplier about application and follow their recommendations on which product to use. Additional information for problem identification and rectification may be obtained from suppliers and consultants. For purposes of this discussion, it is understood that cold-set binding processes include alginates, Pearl Meat F, Fibrimex or ActivaTM. Some references to conventional restructuring may be made and this process utilizes salts and phosphates in heat-set binding of muscle proteins. Problems with cold-set restructured products can be classified into three major categories. These categories include defects related to appearance, texture and flavor of the restructured item. Solutions for these problems and many others may require careful evaluation of the defective product and

© Woodhead Publishing Limited, 2011

292

Processed meats

processing procedures to ensure corrective actions are successful. As coldset binding is essentially based on chemical reactions of nonmeat ingredients, it is very important that processors understand the binding process before undertaking even modest formulation changes. Surprisingly poor results are frequently encountered by even slight modifications as the chemical reactions required for cold-set binding are sensitive to imbalances.

11.9.1 Appearance Appearance is critical for the acceptance of any meat product by consumers. Cold-set products have many of the same detracting characteristics as conventionally processed restructured products and therefore solutions to some of these problems are common to both types of product. Unattractive particle size, poor lean to fat ratio and discoloration represent some of the significant defects in the appearance of products using these technologies. Typical appearance defects related to processing can be generally attributed to particles being either too large or too small. Size reduction is accomplished by mincing, or flaking fresh or tempered meat through commonly available equipment, and is usually easily modified by choosing appropriate plates, equipment settings, or raw material temperature. A relatively common practice is to use coarsely minced lean material in combination with finely minced fat material to mimic marbling. Careful trimming of starting material is the key to successfully making these products. Unacceptable lean to fat ratio is attributed mainly to poor selection of raw materials. Within the US meat trimmings containing excess fat tend to be the most economical so they are often formulated to maximum levels. Separation of lean and fat materials, coupled with formulations of limited total fat content can be helpful. Most beef steaks contain less than 10–15% fat. When the separate meat materials are minced or flaked appropriately they can be mixed and cold-set binding can proceed. A major problem with appearance is discoloration. Conventionally processed products are highly susceptible to discoloration due to pigment oxidation and cold-set products are not exempt from this problem. Prior handling and product age also greatly influences finished product color since once the ability of the muscle to reduce myoglobin pigments is depleted the color deteriorates quickly. Selection of raw materials of highest quality and uniformity will overcome most discoloration for cold-set products. Use of similar muscles to guarantee similar color and color stability is also recommended. Some discoloration may also be attributed to the binding ingredients and the gel pockets which sometimes occur. While solutions for this problem are not evident, the size and distribution of the gel can be modified through improvements in mixing. Better mixing minimizes the size of gel pockets seen with alginates and improves distribution for a more uniform appearance. It is very important with all products to remove as much air as possible to prevent discoloration due to trapped air.

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

293

11.9.2 Texture Acceptable products can be manufactured using cold-set binders. However, there are many instances where poor cohesion or a weak binding occurs. There can be numerous causes for these defects, ranging from excessive formulation moisture to improper processing procedures. Other textural defects which can be described as poor mouthfeel include softness, mushiness, slipperiness, graininess and sponginess. In some extreme cases, toughness, rubberiness or excessive bind strength can be encountered. The latter is not usually encountered with cold-set products, but is rather common for conventionally prepared products that have been over mixed. Owing to the chemical reactions involved in the cold-set process, most instances of failure to gel properly are expressed as poor cohesiveness. The causes of such failure are numerous and may be related to imbalances of the ingredients (especially excess water) condition of the raw materials (surface pH, frozen raw materials), over-handling, inappropriate time and temperatures for bond formation, or several other processing deficiencies. Because of the wide variety of causes, it is critical that the processor keep records of all processing procedures and materials when trying to identify inconsistencies. In the case of alginate binders, pH of the meat coupled with inappropriate concentration of organic acid can result in failure because the bind developed too quickly and the ultimate gel is broken by handling, or simply fails to develop because pH remains too high and calcium is not available to create the bind. Obviously, careful balance is required to result in optimum gel formation. Many of the cold-set binders are sensitive to frozen raw materials because of released moisture during the gel formation phase when the products are generally held at temperatures above freezing. Similarly time to forming is very important to all cold-set binders. Product must be filled into molds or casings before the gel starts to form or a poor bind will result. Improper storage of sensitive ingredients or even omission of key ingredients during manufacture may also occur, emphasizing the importance of proper tracking of materials during formulation and mixing. Important control examples include the temperature of the fibrinogen and thrombin just prior to addition since activation of the enzymes occurs at 26.6 °C, it is important the liquids are held at this temperature prior to use. Additionally TGase enzyme is subject to oxidation and enzyme inactivation if opened product is stored improperly. Similarly, other process deviations can occur which are easily remedied through attention to detail. Other challenges remain when product developers use these ingredients in combination with traditional ingredients. For example, salt and phosphate are incompatible with alginate and Pearl Meat F. If these ingredients are added they can effectively prohibit the chemical reaction which forms the binding gel. Attempts to incorporate salts, spices and other flavorings can upset the binding process especially with ingredients having oxidizing components or extremes in pH. Experiments have been performed to determine if extra ingredients can be compatible with cold-set binding,

© Woodhead Publishing Limited, 2011

294

Processed meats

particularly with alginate binder, and most ingredients have been shown to interfere with the gelling process. Fibrimex and ActivaTM, on the other hand can be used on meat that has been marinated and the gel will still form so long as excess marinade does not dilute the matrix. Similarly frozen raw material can pose a problem with many of these systems especially if they melt during the reaction phase. Poor mouthfeel may also be a typical defect in raw restructured preparation of cold-set products. Softness or mushiness is usually correlated to either poor cohesion or poor quality meat. Instances of soft texture may be due to gelation failure or the incorporation of ingredients that tenderize the meat particles too much. Excessively comminuted meats can also be a source of soft texture. Complaints about slippery or grainy texture may be attributed to the ingredients and common sources in the presence of unreacted alginate or too much Pearl Meat F. Incomplete reaction between alginate and calcium may be due to an improper ratio of ingredients or a pH that is too high for the calcium source to become soluble. It is unusual to expect toughness in a restructured product, but a possibility that has to be considered is excessive connective tissue contributed by the raw materials or when excessive TGase is used in a formulation.

11.9.3 Flavor The desirable flavor of meat products is essential for ensuring repeat purchases. Problems with off-flavors can repulse customers and careful investigation and identification of reported flavor defects is critical. Unfortunately, flavor is a subjective evaluation that often varies with the individual, which sometimes makes it difficult to measure the problem by objective means. This makes it nearly impossible to determine the cause and effect in a troubleshooting exercise, but it is hoped that improvement can be achieved. Raw materials and nonmeat ingredients obviously have significant roles in the type and flavor which is found in the product. Any problem due to excessive aging, spoilage, oxidation or similar reduction of quality in the raw meat will carry through to adversely impact the flavor of the restructured meat product. Selection of suitable raw materials of exceptional quality is required to make acceptable commercial products: as the adage goes, ‘garbage in, garbage out’. The development of off-flavor due to the binder ingredients is more problematic as these must be added for restructuring and do not contribute towards the meaty flavor of the product. The processor does have some control over the quantity of binder ingredients and therefore should use the minimum concentration that is effective for the restructuring process. In some cases, the quality and freshness of binder ingredients can be questioned and thus appropriate steps can be taken to prevent off-flavors due to expired ingredients. The customer may perceive a reduction in meat flavor intensity due to the cold-set binders because they tend to coat the meat in order to create

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

295

adhesion, so a criticism of blandness may be reported. This can be compounded by trying to extend the product with extra water. Steps to overcome this problem are more difficult to implement as the traditional method of improving flavour is to add salts, hydrolyzed vegetable protein or other flavour enhancers (monosodium glutamate, fish sauce, soy sauce, etc.). The chemistry of the alginate cold-set binding process and Pearl Meat F would be adversely affect by incorporating ingredients containing salt and although flavor would improve, textural defects would occur. At present, recommendations for reducing blandness are to add flavorings after cold-set binding is complete especially for alginate and Pearl-F bound products. This may be accomplished by the use of a marinade, rub or other post-restructuring addition to the surface of the product. Salt and phosphate with other seasonings can be incorporated into the meat prior to using Fibrimex or ActivaTM for restructured meat products to help minimize blandness. There are numerous considerations when deciding to utilize cold-set binding agents. Use of the cold-set binders allows the manufacture of a raw product that works well in a portion control system. It also allows utilization of high quality trimmings (loin and tenderloin) in products that have a higher value then ground meat. To maximize the quality of the product careful consideration must be given to raw material, particle size reduction and binder to use. Each will determine what type of product will result from the process.

11.10 References and further reading ando, h., adachi, m., umeda, k., matsuura, a., nonaka, m., uchio, r., tanaka, h. and motoki, m. (1989) ‘Purification and characteristics of a novel transglutaminase derived from microorganisms’, Agric. Biol. Chem. 53, 2613–2617. beltrán-lugo, a.i., maeda-martínez, a.n., pacheco-aguilar, r., nolasco-soria, h.g. and ocaño-higuera, v.m. (2005), ‘Physical, textural, and microstructural properties of restructured adductor muscles of 2 scallop species using 2 cold-binding systems’, J. Food Sci. 70(2), E78-E84. berry, b.w., smith, j.j. and secrist, j.l. (1987), ‘Effects of flake size on textural and cooking properties of restructured beef and pork steaks’, J. Food Sci. 52(3), 558–563. boles, j.a. and shand, p.j. (1998), ‘Effect of comminution method and raw binder system in restructured beef’, Meat Sci. 49(3), 297–307. boles, j.a. and shand, p.j. (1999), ‘Effects of raw binder system, meat cut and prior freezing on restructured beef’, Meat Sci. 53, 233–239. boles, j.a. and parrish, jr, f.c. (1990) ‘A sensory and chemical study of precooked microwave reheatable pork roasts’, J. Food Sci. 55, 618–620. carballo, j., ayo, j. and jiménez colmenero, f. (2006), ‘Microbial transglutaminase and caseinate as cold set binders: Influence of meat species and chilling storage’, LWT 39, 692–699. doi:10.1016/j.lwt.2005.03.020 dimitrakopoulou, m.a., ambrosiadis, j.a., zetou, f.k. and bloukas, j.g. (2005), ‘Effect of salt and transglutaminase (TG) level and processing conditions on quality characteristics of phosphate-free, cooked, restructured pork shoulder’, Meat Sci. 70, 743–749, doi:10.1016/j.meatsci.2005.03.011

© Woodhead Publishing Limited, 2011

296

Processed meats

esguerra, c.m. (1994) Quality of Cold-Set Restructured Beef Steaks: Effects of various binders, marination and frozen storage. Meat Industry Research Institute NZ Pub. No. 945, Hamilton, New Zealand. farouk, m.m., hall, w.k., wieliczko, k.j. and swan, j.e. (2005), ‘Processing time and binder effect on the quality of restructured rolls from hot-boned beef’, J. Muscle Foods 16(4), 318–329. flores, n.c., boyle, e.a.e. and kastner, c.l. (2007), ‘Instrumental and consumer evaluation of pork restructured with ActivaTM or with FibrimexTM formulated with and without phosphate’, LWT 40, 179–185, doi:10.1016/j.lwt.2005.09.005. gray , j.i. and pearson, a.m. (1987) ‘Rancidity and warmed-over flavor’ in Pearson, A. M. and Dutson, T.R., Advances in Meat Research, Volume 3 Restructured Meat and Poultry Products, Van Nostrand Reinhold Company, New York, 125–159. hong, g.p., ko, s.h., choi, m.j. and min, s.g. (2008), ‘Effect of glucono-d-lactone and κ-carrageenan combined with high pressure treatment on the physico-chemical properties of restructured pork’, Meat Sci. 79, 236–243, doi:10.1016/j.meatsci. 2007.09.007. huffman, d.l., ly, a.m. and cordray, j.c. (1981), ‘Effect of salt concentration on quality of restructured pork chops’, J. Food Sci. 46, 1563–1565. hunt, m.c. and kropf, d.h. (1987) ‘Color and appearance’ in Pearson, A.M. and Dutson, T.R., Advances in Meat Research Volume 3 Restructured Meat and Poultry Products, Van Nostrand Reinhold Company, New York, 125–159. katayama, k., chin, k.b., yoshihara, s. and muguruma, m. (2006), ‘Microbial transglutaminase improves the property of meat protein and sausage texture manufactured with low-quality pork loins’, Asian-Aust. J. Anim. Sci. 19(1), 102–108. kerry, j.j., stack, f. and buckley, d.j. (1999). ‘The rheological properties of exudates from cured porcine muscle: effects of added non-meat proteins’, J Sci. Food Agric. 79, 101–106. kilic, b. (2003), ‘Effect of microbial transglutaminase and sodium caseinate on quality of chicken döner kebab’, Meat Sci. 63, 417–421. kolle, d.s. and savell, j.w. (2003), ‘Using ActivaTM TG-RM to bind beef muscles after removal of excessive seam fat between the m. longissimus thoracis and m. spinalis dorsi and heavy connective tissue from within the m. infraspinatus’, Meat Sci. 64, 27–33. kuraishi, c., sakamoto, j., and soeda, t. (1996). Chapter 3 ‘The usefulness of transglutaminase for food processing’ in Biotechnology for Improved Foods and Flavors, ACS Symposium Series 637, American Chemical Society, Washington, DC, 29–38. kuraishi, c., sakamoto, j., yamazaki, k., susa, y., kuhara, c. and soeda, t. (1997), ‘Production of restructured meat using microbial transglutaminase without salt or cooking’, J. Food Sci. 62(3), 488–490, 515. lawrence, t.e., dikeman, m.e., hunt, m.c., kastner, c.l. and johnson, d.e. (2004). ‘Effects of enhancing beef longissimus with phosphate plus salt, or calcium lactate plus non-phosphate water binders plus rosemary extract’, Meat Sci. 67, 129–137. lennon, a.m., moon, s.s., ward, p., o’neil, e.e. and kenny, t. (2006). ‘Effects of enhancement procedures on whole and re-formed beef forequarter muscles’, Meat Sci. 72, 513–517. marriott, n.g., phelps, s.k., costello, c.a. and graham, p.p. (1987), ‘Restructured pork with texture variation’, J. Food Qual. 10, 425–435. means, w.j. and schmidt, g.r. (1986) ‘Algin/calcium gel as a raw and cooked binder in structured beef steaks’ J. Food Sci. 51(1), 60–65. means, w.j. and schmidt, g.r. (1987) ‘Restructuring fresh meat without the use of salt or phosphate’ in Pearson, A. M. and Dutson, T.R., Advances in Meat Research Volume 3 Restructured Meat and Poultry Products, Van Nostrand Reinhold Company, New York, 125–159.

© Woodhead Publishing Limited, 2011

Use of cold-set binders in meat systems

297

means, w.j., clarke, a.d., sofos, j.n. and schmidt, g.r. (1987) ‘Binding, sensory and storage properties of algin/calcium structured beef steaks’, J. Food Sci. 52(2), 252–256, 262. miller, m.f., davis, g.w., seideman, s.c., ramsey, c.b. and rolan, t.l. (1986), ‘Effects of various phosphates on the palatability, appearance and storage traits of flaked and formed restructured beef steaks’, J. Food Sci. 51(6), 1435–1438. moreno, h.m., carballo, j. and borde ias, a.j. (2008) ‘Influence of alginate and microbial transglutaminase as binding ingredients on restructured fish muscle processed at low temperature, J Sci. Food Agric. 88, 1529–1536, doi:10.1002/ jsfa.3245. motoki, m. and seguro, k. (1998). ‘Transglutaminase and its use for food processing’, Trends Food Sci. Tech. 9, 204–210. nielsen p.m. (1995) ‘Reactions and potential industrial applications of transglutaminase. Review of literature and patents’, Food Biotechnol. 9(3), 119–156. offer, g., and trinick, j. (1983) ‘On the mechanism of water holding in meat: the swelling and shrinking of myofibrils’, Meat Sci. 8, 245. payne, c.a. (2000). Non-thermal gelation. Proc. 53rd Reciprocal Meat Conference. 53, 25–26. raharjo, s., dexter, d.r., worfel, r.c., sofos, j.n., solomon, m.b., shults, g.w. and schmidt, g.r. (1995), ‘Quality characteristics of restructured beef steaks manufactured by various techniques’, J. Food Sci. 60(1), 68–71. ramirez-suarez, j.c. and xiong, y.l. (2003), ‘Effect of transglutaminase-induced cross-linking on gelation of myofibrillar/soy protein mixtures’, Meat Sci. 65, 899– 907, doi:10.1016/S0309–1740(02)00297–8. recio, h.a., savell, j.w., leu, r., cross, h.r. and smith, g.c. (1986), ‘Effect of degree of connective tissue removal on raw material yield, chemical and sensory characteristics of restructured beef steaks, J. Food Sci. 51, 1173–1175. ruiz, c.f., higginbotham, d.a., carpenter, j.a., resurreccion, a.v.a. and lanier, t.c. (1993) ‘Use of chuck muscles and their acceptability in restructured beef/surimi steaks’, J Anim. Sci. 71, 2654–2658. schaake, s.l., means, w.j., moody, w.g., boyle, e.a. and aaron, d.k. (1993), ‘Boning methods and binders affect bind and sensory characteristics of structured beef’, J. Food Sci. 58(6), 1231–1236. secrist, j.l. (1987) ‘Restructured meats – the past and present’ in Pearson, A.M. and Dutson, T.R., Advances in Meat Research Volume 3 Restructured Meat and Poultry Products, Van Nostrand Reinhold Company, New York, 125–159. sen, a.r. and karim, s.a. (2003), ‘Effect of meat particle size on quality attributes of restructured mutton steaks’, J. Food Sci. Technol. 40(4), 423–425. shand, p.j., sofos, j.n. and schmidt, g.r. (1993), ‘Properties of algin/calcium and salt/ phosphate structured beef rolls with added gums’, J. Food Sci. 58(6), 1224–1230. smith, d.r. (1984) ‘Restructured meat products: a review’, Food Tech. Aust. 36(4), 178–182. tammatinna, a., benjakul, s., visessanguan, w. and tanaka, m. (2007) ‘Gelling properties of white shrimp (Penaeus vannamei) meat as influenced by setting condition and microbial transglutaminase’, LWT 40, 1489–1497, doi:10.1016/j.lwt.2006.11.017. téllez-luis, s.j., uresti, r.m., ramírez, j.a. and vázquez, m. (2002), ‘Low-salt restructured fish products using microbial transglutaminase as binding agent’, J. Sci. Food Agric. 82, 953–959, doi:10.1002/jsfa.1132. theno, d.m., siegel, d.g. and schmidt, g.r. (1978a), ‘Meat massaging: effects of salt and phosphate on the microstructural composition of the muscle exudates’, J. Food Sci. 43, 483–487. theno, d.m., siegel, d.g. and schmidt, g.r. (1978b), ‘Meat massaging: effects of salt and phosphate on the microstructure of binding junctions in sectioned and formed hams’, J. Food Sci. 43, 493–498.

© Woodhead Publishing Limited, 2011

298

Processed meats

trout, g.r. (1989), ‘The effect of calcium carbonate and sodium alginate on the color and bind strength of restructured beef steaks’, Meat Sci. 25, 163–175. trout, g.r. and schmidt, g.r. (1986), ‘Effect of phosphates on the functional properties of restructured beef rolls: the role of pH, ionic strength, and phosphate type’, J. Food Sci. 51(6), 1416–1423. tseng, t.f., tsai, c.m., yang, j.h. and chen, m.t. (2006), ‘Porcine blood plasma transglutaminase combined with thrombin and fibrinogen as a binder in restructured meat’, Asian-Aust. J. Anim. Sci. 19(7), 1054–1058. tsi, g.j., lin, s.m, and jiang, s.t. (1996) ‘Transglutaminase from Streptoverticillium ladakanum and application to minced fish product’, J. Food. Sci. 61(6), 1234–1238, 1164. vácha, f., novik, i., spicˇka, j. and podola, m. (2006), ‘Determination of the effect of microbial transglutaminase on tehcnological progperies of common carp (Cyprinus carpio L.) meat’, Czech. J. Anim. Sci. 51(12), 532–545. wijngaards, g. and paardekooper, e.j.c. (1987),’Preparation of a composite meat product by means of an enzymatically formed protein gel’, in Trends in Modern Meat Technology 2 Proceedings of the International Symposium, Den Dolder, The Netherlands, 23–25 November 1987, ed. van Roon Krol P.S., and Houben Pudoc J.H., Wageningen, 125–129. zhu y., rinzema a., tramper j. and bol j. (1995) ‘Microbial transglutaminase – a review of its production and application in food processing’, Appl. Microbiol. Biotechnol. 44, 277–282.

© Woodhead Publishing Limited, 2011

12 Using natural and novel antimicrobials to improve the safety and shelf-life stability of processed meat products A. Lauková, Slovak Academy of Sciences, Slovakia

Abstract: Consumer demand for natural foods and their components has increased recently. This has been driven by informed and affluent consumers who are sold the concept of natural and functional as points of difference in convenience foods. The addition of natural antimicrobials such as plant extracts, as well as the inclusion of new and natural bacteriocin-producing probiotics as functional food adjuncts, have been identified as potential quality indicators for the informed consumer. These adjuncts have also been employed in improving the safety and shelf-life of value-added meat products. The following chapter reviews the general trends in ‘functional’ meats and selected adjuncts in terms of their emergence as well as current and future technological developments. Key words: natural antimicrobials, meat products, stability, shelf-life, probiotics, plants, bacteriocins.

12.1 Introduction The effective extension of meat shelf-life and confidence in its scrutiny is an important challenge for the meat industry. Natural antimicrobial compounds have long been used for their effect on several food spoilage microorganisms and pathogens. Common spices and aromatic plants have been used in cooking, not only for their taste-enhancing properties, but also for their antibacterial effect (Conner, 1993). Lactic acid bacteria (LAB) have been effectively employed for their preservative effect which is due to the production of one or more metabolites with antimicrobial properties, such as organic acids (e.g. lactic and acetic). The action of these metabolites is enhanced by reducing the pH of the media. Many bacteriocins and/or lantibiotics produced by LAB have also been identified and shown to have antibacterial properties. Among these is

© Woodhead Publishing Limited, 2011

300

Processed meats

nisin which is produced by certain strains of Lactococcus lactis subsp. lactis (Hurst, 1981; Sahl and Bierbaum, 1998; De Vuyst and Vandamme, 1994), helveticin V-1829 produced by Lactobacillus helveticus 1829 (Vaughan et al., 1992), leucocin B-Ta11a produced by Leuconostoc carnosum Ta11a isolated from meat (Felix et al., 1994), lacticin 3147 produced by L. lactis subsp. lactis DPC3147 (Ryan et al., 1996), amylovorin L471 produced by Lactobacillus amylovorus DCE 471 (De Vuyst et al., 1996), bavaricin MN produced by Lactobacillus sakei (Kaiser and Montville, 1996), acidocin J1229 produced by Lactobacillus acidophilus JCM 1229 (Tahara and Kanatani, 1996), pediocin K7 produced by Pediococcus acidilactici (Erkkilä and Petäjä, 2000), plantaricin TF711 produced by Lactobacillus plantarum TF711, isolated from Tenerife cheese (Hernández et al., 2005). LAB-derived bacteriocins are attracting commercial interest because they are generally recognised as safe (GRAS) and as being attractive additives for use in the meat industry. Their activity against the key pathogens involved in foodborne illnesses, such as Listeria monocytogenes or Staphylococcus aureus, have been well reported (Hudault et al., 1997; Lauková et al., 1999b; Budde et al., 2003). One of the beneficial properties of LAB is their probiotic character (Ouwehand et al., 1999). Probiotic meat products are of primary importance to the industry in developing a pro-health strategy. Rebucci et al. (2007) proved that daily consumption of 50 g of raw cured probiotic sausage will effectively regulate the immune system. There are also reasons to believe that the sausage matrix protects the survival of probiotic lactobacilli throughout the gastrointestinal tract (Klinberg and Budde, 2006). The most effective bacteria are those which are commonly associated with the meat environment. The commercial meat starter cultures L. sakei Lb3 and P. acidilactici PA-2 may be of interest because of their capacity to survive under simulated gastrointestinal conditions. Enterococci which belong to LAB have also been shown to have a probiotic character (Franz et al., 1999). Moreover, they have been found to produce bacteriocins (mostly enterocins, Galvéz et al., 1986; Lauková et al., 1993; Aymerich et al., 1996; Casaus et al. 1997; Cintas et al., 1997, 1998, 2000; Floriano et al., 1998; Foulquié Moreno et al., 2003; Mareková et al., 2007). In spite of many discussions concerning their use in food matrices, these showed many beneficial effects. The German Chemical Industry has published a brochure promoting safe biotechnology which classifies microorganisms into specific risk groups (Berufsgenossenschaft der Chemischen Industrie, 1995). Based on this classification, Group 1 bacteria pose no risk for human or animal health and include the majority of LAB as well as other types. Bacteria in Group 2 are considered to have a low potential for causing infection, dependent upon the immune status of the host, and are not generally regarded to be necessary pathogens. In contrast, Group 3 encompasses organisms having a high potential for infection. According to this classification, most Enterococcus spp. are listed in Group 2, exceptions being indicated for the strains Entero-

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

301

coccus faecium and Enterococcus durans on the basis of safe technical evidence and may therefore be considered as non-risk strains in the sense of Group 1 organisms. The European Food Safety Authority (EFSA) has provided and contributed EU Directives for regulating and assessing probiotic additive/adjuncts. The EFSA has also taken responsibility for launching the European initiative towards a Qualified Presumption of Safety (QPS) concept which is similar to GRAS in the USA and which allows strains with an established safety status to enter the market without extensive testing requirements (EFSA, 2004). In 2006, the EFSA established the Nutrition & Health Claims regulation (Reg. 1924/2006) which was updated by QPS under EFSA’s Panel on Biological Hazards (BIOHAZ) during 2008 and 2009. The presence of transmissible antibiotic resistance markers in the evaluation of the strains has been established as the important health criterion (Piskoriková, 2010). Following these rules, microbes claimed as probiotic in food are supposed to be QPS probiotic, e.g. Lactobacillus casei or Bacillus sp. and non-QPS probiotic E. faecium (Piskoriková, 2010). However, it is necessary to base the claims on individual strains within the framework of the species, and to ascertain the antibiotic sensitivity, safety, absence of toxins and virulence factors of each strain through toxicological studies such as three pack genotoxicity studies and sub-chronic tests (90 day rat study). In contrast to the enterococcal strains, enterococcal bacteriocins produced by heterologous hosts or added as cell-free partially purified preparations, have proved effective in application.

12.2 Range of natural antimicrobials for food application Many naturally occurring extracts such as essential oils from edible and medicinal plants, herbs and spices, have been shown to possess antimicrobial functions and could serve as a source of antimicrobial agents against food spoilage and pathogens (Zaika, 1988; Bagamboula et al., 2003; Oussalah et al., 2006). Essential oils are odorous, volatile products of the secondary metabolism of aromatic plants and are normally formed in special cells, or groups of cells, in leaves and stems. Essential oils have long served as flavouring agents in food and beverages and owing to their varied content of antimicrobial compounds, they have potential as natural agents for food preservation (Conner, 1993). Their antimicrobial activity is assigned to a number of small terpenoid and phenolic compounds, which in their pure form have also been shown to exhibit antibacterial or antifungal activity. The antibacterial properties of these compounds are in part associated with their lipophilic character, leading to their accumulation in membranes and to subsequent membrane-associated events, such as energy depletion (Karapinar and Aktung, 1987; Conner, 1993). Numerous definitions have been proposed for the term probiotics. Among the more widespread is that reported by Fuller (1989), which defines

© Woodhead Publishing Limited, 2011

302

Processed meats

probiotic as a live microbial food or food supplement which beneficially affects the host through improving its intestinal microbial balance. According to the definition of the World Health Organization (WHO), probiotics are live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host (Fuller and Gibson, 1997). According to the FAO/WHO (2001) definition, the main criterion for a probiotic strain is that it confers a health benefit on the host. Recently, the term ‘functional’ starter culture has been presented as a new definition (Tyopponen et al., 2003; Léroy et al., 2006); where the use of selected probiotic or bacteriocinproducing strains are the primary meat starter culture. More research with respect to human studies is needed to justify the launch of new probiotics, particularly of probiotic fermented sausages. It is important that this research should adhere rigorously to the guidelines formulated by the FAO/ WHO (2002). These include detailed identification of the strain and of the approved beneficial health effect of the food product. No other approach will be sufficiently credible to persuade producers, consumers and policy makers of the intrinsic value of probiotic fermented meat products, or to contribute to a recognition of meat products as healthy foods (De Vuyst et al., 2008). The other type of natural antibacterials are represented by bacteriocins. These are antimicrobial peptides or proteins which are ribosomally synthesised and produced by the activity of bacteria with more or less closely related species (Klaenhammer, 1993; Jack et al., 1995; Nes et al. 2002). Those bacteriocins which are produced by LAB are mostly antimicrobial peptides which are generally heat-stable, apparently hypoallergenic, and readily degraded by proteolytic enzymes in the human intestinal tract (Aymerich et al., 2008). Bacteriocins are generally categorised into three different classes according to their biochemical and genetic properties (Drider et al., 2006). Class I peptides are the lantibiotics, which are small, post-translationally modified peptides which contain unusual amino acids such as lanthionine (Hurst, 1981). Class II peptides include unmodified bacteriocins which are subdivided into three subclasses, namely, class IIa (pediocin-like bacteriocins), class IIb (two-peptide bacteriocins) and IIc (other, one-peptide bacteriocins). The class III peptides are thermo-sensitive proteins. Although some bacteriocins have been tested in food, nisin remains the only commercial source and the only one regulated as an additive by European Commission (although not in meat products). It was admitted into the European food additive list, where it was assigned the number E234 (EEC, 1983). Nisin was also approved by the Food and Drug Administration (1988) in the USA as GRAS.

12.2.1 Probiotics as natural antimicrobials for food preservation Lactic acid bacteria (and/or their antimicrobial products such as lactic acid, bacteriocins) have a long history of safe use in foods as the natural

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

303

microflora of meat and other foods (e.g. milk, vegetables, fish products). They exert their effect through competition for nutrients and/or production of the above-mentioned antimicrobial substances. They may be added during the preparation of meat batters, sprayed onto surface of the meat, or added indirectly through active packaging, depending on the type of product application (Hugas, 1998; Aymerich et al., 2008). L. rhamnosus GG is a well-known probiotic lactic acid bacterial strain which is used to ferment dairy products (Saxelin, 1997). Lactobacillus rhamnosus E-97800 is a new probiotic strain isolated from human faeces (Kontula et al., 1999) and LC-705 is a bioprotective used to ferment dairy products (Mäyrä-Mäkinen and Soumalainen, 1995). This probiotic strain has been successfully used to produce dry sausage (Erkkilä et al., 2001). During the fermentation process, the numbers of inoculated LAB increased from log10 7.0 to 8–9.0 log10 cfu/g and the pH values decreased from 5.6 to 4.9–5.0. The sensory test indicated that the dry sausages fermented by LC-705 strain were inferior to the control sausages. The concentrations of biogenic amines remained low during the ripening process. The indication is that especially GG strain and E-97800 are suitable for use as probiotic starter cultures in fermenting dry sausage. Arihara et al. (1998) showed that the potentially probiotic strain Lactobacillus gasseri JCM1131 can be used for meat fermentation to enhance product safety. Lactococcus lactis DPC4268 is widely used in Ireland in the manufacturing of Cheddar cheese. It is a quick and reliable means of producing acid in a dairy environments. A transconjugant of this strain, L. lactis DPC4275, produces two-peptide bacteriocin lacticin 3147. Both strains were used to manufacture salamis which were then compared in terms of pH, water activity (Aw), weight loss, colour development and sensory characteristics with those produced by conventional starter cultures (Staphylococcus carnosus, L. sakei; Coffey et al., 1998). Salamis produced with lacto-coccal cultures exhibited pH values below 5.1 and Aw values below 0.90, which is favourable for preservation and hygienic stability. They also had good sensory and colorimetric qualities. Among enterococci, several E. faecium and E. faecalis strains have already been used as veterinary feed supplements. Since February 2004, 10 preparations have been authorised as additives for feeding stuffs in the European Union (European Commission, 2004). The British Advisory Committee on Novel Foods and Processes (ACNFP, 1996) has accepted the use of E. faecium strain K77D as a starter culture in fermented dairy products. Enterococci have been used in many different applications as starter or adjunct cultures and probiotics (Giraffa et al., 1997; Fuller, 1989), as they have better proteolytic activity than the other LAB strains, which is particularly important in cheese ripening. As probiotics, they may contribute to the improvement of microbial balance and to the treatment of gastroenteritis in humans and animals, the alleviation of lactose intolerance and the reduction of blood cholesterol levels as well as improving the nutritional value

© Woodhead Publishing Limited, 2011

304

Processed meats

of foods (Bellono et al., 1980; Franz et al., 1999; Lauková et al., 2003a, 2006; Marcinˇáková et al., 2004; Strompfová et al, 2006; Foulquié Moreno et al., 2006). The isolation of enterococci from raw meat products has been reported, which may be caused by cross-contamination at the time of slaughter. Isolated strains of E. faecium and E. faecalis have been identified as the dominant species in different meat types, including beef, pork, rabbit and poultry (Knudtson and Hartman 1993; Marcinˇáková et al., 2005a; Simonová, 2006). Microbial analysis of fermented meat products – salami or sausages – revealed enterococci in numbers ranging from up to 105 cfu/g (Teuber et al., 1996; Aymerich et al., 2003; Simonová et al., 2004). According to the European Food Safety Authority (EFSA, 2004) enterococci must undergo more rigorous testing in order to guarantee that only safe strains are deliberately introduced into the commercial food chain. The reason why a more rigorous attitude is being adopted is because enterococci often carry transferable antibiotic resistance or virulence factors (Franz et al., 2007). However, when Callewaert et al. (2000) used two different non-meat Enterococcus strains (CCM 4231, RZS C13) as starter cultures in the preparation of Spanishstyle dry fermented sausage, the competitiveness and anti-Listeria activity of both strains was monitored during fermentation on both the laboratory and pilot scale. On the other hand, when E. faecium CTC 492 was added as starter culture, it did not significantly reduce Listeria counts when compared with the standard starter culture (Aymerich et al., 2000). An inverse effect was observed for enterocin CTC 492 which significantly reduced Listeria counts.

12.2.2 Bacteriocins as natural antimicrobials for food preservation It is safe to say that the bacteriocins produced by Gram-positive bacteria, especially lactic acid-producing strains, are the most investigated group of antibacterial peptides, given their potential for commercial applications in foods and other products. The most studied strains are those bacteriocins produced by LAB (Nes and Holo, 2000; Chen and Hoover, 2003; Drider et al., 2006). Underlining their importance, Gálvez et al. (2008) reported their impact in applications to control food-borne pathogens and spoilage bacteria. Nisin Nisin, the only bacteriocin used commercially for preservation, is a peptide composed of 34 amino acid residues. It has a molecular mass of 3.5 kDa, and is classified as a class Ia bacteriocin or lantibiotic (Hurst, 1981; Sahl and Bierbaum, 1998). Commercially, nisin is involved in the preparation NisaplinTM (Aplin & Barrett Ltd, Wilts, UK). Nisin is a highly surface-active molecule which is capable of binding to different compounds, e.g. fatty acids

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

305

or phospholipids. This makes it suitable for adsorption to solid surfaces and for killing the bacterial cells which subsequently adhere (Sobrino-López and Martín-Belloso, 2008). It permeates the cytoplasmic membrane by forming pores in the membrane, resulting in a rapid efflux of small molecules (Ray, 1992). Nisin is active against Gram-positive bacteria (Hurst, 1981; Lauková, 1995; Delves-Broughton et al. 1996); however, its inhibitory activity against some Gram-negatives is also demonstrated and explained by the sensitivity of Gram-negatives to nisin by permeabilisation of the outer membrane layer caused by sub-lethal heating, freezing and/or use of selected chelating agents (Delves-Broughton et al. 1996, Lauková, 2000; Boziaris and Adams, 2001). Chung et al. (1989) reported that nisin delayed bacterial growth on meats artificially inoculated with L. monocytogenes and S. aureus for at least one day at room temperature. At an incubation temperature of 5 °C, growth of L. monocytogenes was delayed for more than two weeks and growth of S. aureus did not occur. But they did not note any inhibition of Serratia marcescens, Pseudomonas aeruginosa and Salmonella enterica Typhimurium. When nisin was added to boiling water and used to treat L. monocytogenes which were either directly suspended in the water or attached to turkey skin, there was at least a 1 log decrease of Listeria. Further reduction followed when the samples were stored under refrigeration. After 48 hours of refrigeration, a 2 log decrease was noted after nisin treatment. Heat exhibited a synergistic relationship with the nisin when the cells were directly suspended in boiling water (Mahadeo and Tatini, 1994). Nisin enhanced inactivation of S. Typhimurium after seven days when stored at 6.5 °C in peptone water (1.7 log decrease in the presence of 100 IU nisin compared with controls, P < 0.0001) and Escherichia coli O157 : H7 (1.6 log decrease, P < 0.001; Elliason and Tatini, 1999). Scanell et al. (1997) reported a longer shelf-life and an increased protection against S. aureus and some cells of Salmonella Kentucky in laboratory infected fresh pork sausage following nisin treatment. The reduction of Salmonella by nisin may be due to the cell being damaged, either by its osmotic condition (due to presence of salt or lactate) or by a combination of those factors which would allow nisin to penetrate the cell membrane (Harris et al. 1992). In fresh meat, nisin has been sprayed onto red meat carcasses to sanitise the surface (Cutter and Siragusa, 1994). However, the practical application of nisin is often limited because of its low stability and activity at high pH, and consequent limited efficacy in certain food matrices. Moreover, the emergence of nisin tolerance in certain bacteria (L. monocytogenes) has been observed (Schillinger et al., 1996). Nisin may be inactivated by gluthatione in a reaction catalysed by gluthatione S-transferase. As gluthatione is found in raw meat, nisin activity may be diminished by this reaction. However, bacteriocins from other LAB have often been used experimentally to prevent spoiling, as well as to prolong the shelf-life of meat products (Ming et al., 1997; Hugas et al., 1998, Schoebitz et al., 1999).

© Woodhead Publishing Limited, 2011

306

Processed meats

Other bacteriocins and their use in meat processing Listeriae have often been detected within meat systems (Jay, 1996) and their implication in serious food poisoning outbreaks on a global basis is well documented. Therefore, their potential outgrowth within processing facilities and on foods has to be strictly monitored and controlled, especially in the case of L. monocytogenes. Consequently, a range of bacteriocins, including nisin, have been successfully tested as potential reductive agents. Alternative bacteriocins such as sakacin K, produced by L. sakei CTC 494 (Hugas et al., 1998) have been reported to inhibit the growth of Listeria innocua in vacuum-packed samples of raw poultry breasts and cooked pork, as well as in modified atmosphere packaging (MAP) samples of raw minced pork. Schoebitz et al., (1999) found complete inhibition of L. monocytogenes within vacuum-packed meat after 14 days storage at 4 °C after treatment with bacteriocin produced by Carnobacterium piscicola L103. Further studies on packed meat and poultry samples inoculated with L. monocytogenes and pretreated or coated with pediocin powder (P. acidilactici K), showed the cells of L. monocytogenes to be completely inhibited on test products throughout 12 weeks of storage (Ming et al., 1997). It is also hypothesised that reducing agents (e.g. enterocins, bacteriocins) produced by different enterococci within meat ecosystems, influence or inhibit the outgrowth of spoilage microflora (Franz et al., 2007). Enterocins and meat manufacturing Enterococci enter raw foods of animal origin via intestinal or environmental colonisation. They may survive and multiply during fermentation (Giraffa, 2002). Enterococci in fermented foods may also reflect a certain level of contamination or a poor curing process. However, enterococci display some useful biotechnological traits, including the production of bacteriocins (Lauková et al., 1993; Aymerich et al., 1996; Casaus et al., 1997; Cintas et al., 1997, 1998, 2000; Floriano et al., 1998; Herranz et al., 2001; Sabia et al., 2002; Foulquié Moreno et al., 2003; Mareková et al., 2007). Some strains are bacteriocin producing and also possess some probiotic characteristics (Lauková et al. 2003a, 2008a; Simonová, 2006; Strompfová and Lauková, 2007; Szabóová et al., 2008a; Lauková et al., 2008a). Antibacterial peptides (bacteriocins) produced by enterococci are generally called enterocins. A simplified classification scheme of three classes is proposed for enterocins: Class I enterocins (lantibiotic enterocins), Class II enterocins (small, nonlantibiotic peptides), Class III enterocins (cyclic enterocins) and Class IV enterocins (large proteins). Class II may be subdivided into three subclasses: II-1, enterocins of the pediocin family; II-2, enterocins synthesised without a leader peptide; and II-3, other linear, nonpediocin-type enterocins (Franz et al., 2007). Cytolysin produced by a strain of E. faecalis is the only lantibiotic-type enterocin which is currently known. This is a two-peptide bacteriocin and both structural subunits contain lanthionine residues (Booth et al., 1996). Ent A and P belong to enterocins of the pedio-

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

307

cin family (Franz et al., 2007). Although Ent M (Mareková et al., 2007) was not classified as part of this group until recently, its similarity with Ent P suggested its allocation to Class II-1. Enterocins L50A and L50B and Ent Q were allotted to the category of enterocins which are synthesised without a leader peptide, while Ent B is characterised as the other non pediocin-like enterocin. Cyclic antibacterial peptides involve enterocin AS-48 (Gálvez et al., 1986) as Class III. Class IV is represented by enterolysins (Nigutová et al., 2007). The antibacterial effect of enterocins is interlinked. However, enterocin CRL35 produced by E. faecium CRL35 isolated from cheese, was found to inhibit the in vitro multiplication of different tk+ and tk− (thymidin-kinase positive and deficient) strains of HSV-1 (herpes simplex) and HSV-2. It provided the first example of the antiviral effect of enterocins (Wachsman et al., 1999). Several studies have been reported which have used bacteriocins (enterocins) in meat protection or processing (Lauková et al., 1999a; Aymerich et al., 2000; Ananou et al., 2005). The microbial ecology of meat products depends mainly on the environment, the meat type and species, additives, equipment, handling practices, processing, packing and storage temperatures. The conditions in meat are often changed by psychrotrophic bacteria and by the occurrence of S. aureus, Bacillus cereus or listeriae (Nychas and Arkoudelos, 1990; Incze, 1998; Sachindra et al., 2005). However, recent studies have been published where addition of enterocin CCM 4231 (produced by non-meat origin E. faecium CCM4231 strain) has been completed during the preparation of dry fermented salami Hornád experimentally contaminated meat with L. monocytogenes and following the treatment of test products with enterocin, reported a reduction of L. monocytogenes by 1.67 log cycle (Lauková et al., 1999a). When applied in fermented sausages, Enterocin A and B produced by E. faecium CTC 492, significantly diminished Listeria counts by 1.13 log (P < 0.001; Aymerich et al., 2000). However, as mentioned in Section 12.2.1, the addition of CTC 492 to meats did not have an anti-listerial effect (Aymerich et al., 2000). While a slight re-growth of Listeria was found in Gombasek sausage treated with Ent M (produced by non-meat origin strain E. faecium AL41) at the end of ripening, an inhibitory effect (the bacteriostatic effect) was demonstrated (2.7 log reduction). The pH value was not influenced and the amount of lactic acid was between 0.041 and 0.112 mmol/l (Lauková et al., 2003b). Ananou et al. (2005) used enterocin (Ent) 48 produced by E. faecalis AS-48 for the control of S. aureus in processed meats. They reported that 30 or 40 μg/g of Ent AS-48 inhibited proliferation of S. aureus in sausages, achieving a significant reduction of 2 and 5.31 log units respectively, in viable counts (cfu/g) of staphylococci when compared to the untreated control. S. aureus is considered the second or third most common pathogen after Salmonella and Clostridium perfringens in causing outbreaks of food poisoning (Todd, 1983). The presence of bacteriocin also had a moderate negative effect on total LAB. In all cases, however, inhibitory activity in the

© Woodhead Publishing Limited, 2011

308

Processed meats

product itself could not be detected. This could be influenced by the fat matrices of the product and the low lipid solubility of bacteriocin, etc. (Coffey et al., 1998; Cleveland et al., 2001). Furthermore, the efficacy of the enterocin inhibitory activity could also be influenced by its purity, activity and levels of the concentration utilised. In most studies, the bacteriostatic effect of enterocins has been clearly demonstrated. Similarly, in contrast to enterococcal strains, enterococcal bacteriocins produced by heterologous hosts or added as cell-free, partially purified preparations, may have potential for application in meat preparations (Franz et al., 2007); especially those enterocins with broad inhibitory spectra against food spoilage and pathogenic organisms which indicate their utility as bio-preservative agents. Novel bacteriocins and innovative alterations in meat processing Coagulase-negative staphylococci (CNS), micrococci and LAB are bacteria commonly isolated in many food products (Coppola et al., 1997; MorotBizet et al., 2003; Simonová et al., 2006). Staphylococcus xylosus and S. carnosus are the dominant flora and are commonly utilised as lipolytic starter cultures for fermented sausages (Jessen, 1995; Talon and Montel, 1997; Simonová et al., 2006; Essid et al., 2007). Staphylococci also play an important role in the development of the aroma, flavour and colour of fermented products, where they are able to reduce nitrate to nitrite (the production of nitrosylmyoglobin is necessary for the formation of red colour in these traditional products). Their catalase activity decomposes hydrogen peroxide and prevents lipid oxidation (Skibsted, 1992; Jessen, 1995; Talon and Montel, 1997; Barriére et al., 2001). Many coagulase-negative staphylococci as well as enterococci (not only those of food origin) are able to produce bacteriocins (Lauková and Mareková 1993; Villani et al., 1997; Franz et al., 2007). Bacteriocin-producing strains may be used as starter cultures (S. xylosus) or bacteriocin-producing enterococci as cocultures which are effective during the first stages of the fermentation process. For example, S. xylosus SX S03/1M/1/2 (Simonová et al., 2006) was first isolated from traditionally produced (non starter type) Slovak sausage. This strain produces lactic acid and is tolerant to 1% oxgall (bile). The SX S03/1M/1/2 strain is sensitive to antibiotics, possesses an adequate adhesive ability and is decarboxylase-negative as well as being a bacteriocinproducing strain. These properties have technological potential for use in salami or sausage manufacturing. Based on studies undertaken, S. xylosus SX S031M/1/2 displayed adequate colonisation in test salamis. Even after ripening for four weeks, this was enumerated at 4.5 log cfu/g from the initial count of 6.6 cfu/g. Bacterial counts for lactic acid bacteria in test salami were higher (up to log10 9.27 cfu/g and 10.2 cfu/g). S. aureus was found under the detection limit (<1.7). The counts of enterobacteriae were also shown to have decreased. An insignificant reduction in mould growth was detected with differences of P < 0.01 recorded when compared with controls after two weeks of ripening. Similarly, yeast counts were significantly decreased

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

309

in the test samples after one day and after one week (P < 0.001). However, the pH and water activity were not influenced by the SX S031M/1/2 strain. The activity of the bacteriocin produced by SX S03/1M/1/2 strain reached 800–1600 AU/ml in the pH range 5.0–7.0. This substance did not cease its activity after heat treatment (Lauková, in Final Report, Tradisausage, QLK1-CT-2002-02240, www.clermont.inra.fr/tradisausage/index.htm). Similarly, Villani et al. (1997) described the S. xylosus 1E strain isolated from Italian sausage as capable of producing antibacterial substances active against L. monocytogenes in the production of Naples-type sausage. Results for test salami products containing S. xylosus 1E after 21 days of maturation, in which L. monocytogenes was initially added to the meat, showed that viable counts of the pathogens were reduced by approximately two log cycles, whereas a 0.5 log reduction occurred in the control containing only the pathogen. After 75 days of fermentation, no cells of L. monocytogenes remained in the sausages treated with the 1E strain, whilst levels of the pathogen were still present in the control. It is also possible to use bacteriocins as additives to the sausage mixture as an alternative to using viable cells. This offers a safer means of natural food preservation while minimising the potential decreases in organoleptic acceptability and imperfections of flavour which may occur following the addition of live strains (Coffey et al., 1998). E. faecium CCM 4231 is a bacteriocin-producing strain of nonmeat origin (mentioned above on page 307). This strain has been studied for almost 20 years and recently was shown to have the ability to transform linoleic acid (to have an oil source) into conjugative linoleic acid (CLA, Marcinˇáková, 2006). The CLA has been highlighted because of its effect in reducing carcinogenesis, atherosclerosis and body fats (Chin et al., 1992, Nicolosi et al., 1997). A bacteriocinogenic, probiotic strain possessing this additional functional property has increased value for use in meat processing application. Ent CCM 4231 was applied in the preparation of Slovak salami Púchov (Lauková et al., 2008b) which had been experimentally infected with L. innocua LMG 13568. It was found to reduce Listeria counts by 2.48 log after three weeks of ripening. Test salami treated with Ent CCM 4231 showed a 6.5 cfu/g reduction in Listeria when compared against controls (Lauková and Turek, 2004). However, the bacteriocin activity of Ent CCM 4231 itself was not detected in the salami. This could be explained by a reduction in the cell viability of the sausage due to additives used in the manufacturing process for suppressing cell growth; by genetic instability; by the inability to distribute bacteriocin uniformly throughout the product; by low solubility of the bacteriocin within the matrix, inactivation by meat proteases, adsorption to fat and meat particles and by intrinsic factors (pH, Aw, etc., Cleveland et al., 2001; Dicks et al., 2004). However, the engineering of bacteriocin molecules may lead to more active compounds (Miller et al., 1998) or may increase their stability (Johnsen et al., 2000). Bacteriocins are not intended as the sole means of food preservation, but should be integrated

© Woodhead Publishing Limited, 2011

310

Processed meats

in a multi-barrier preservation system respecting good manufacturing practice (Léroy et al., 2006). Future science-based production of engineered bacteriocins could lead to the production of bacteriocins with novel characteristics, generated by either mutating bacteriocin-encoding genes, or by fusing genes from different bacterial species. The genetic modification of bacteriocins and their hosts offers several advantages over use in their native form. For example, it is useful to enlarge the killing spectrum of bacteriocins and the previously mentioned modified bacteriocins could be applied for this purpose (Gillor et al., 2005). However, in practice, these are defined as genetically modified (GM) and in March 2003, the EU upheld a moratorium on GM foods, ingredients and components. It is also standing firm on its decision that any food containing >0.9% of a GM product should be labelled as such (Hellemans, 2003). The concept of substantial equivalence, which has been used for checking the safety of GM foods for human consumption, is based on the principle that if the chemical composition of a modified food is equivalent to that of its natural antecedent, then it is safe (Ahmed, 2003).

12.2.3

The most frequently used plants extracts for achieving shelf-life stability in meat products Several references on the antimicrobial activity of essential oils extracted from plant species are available within the literature (Table 12.1). Examples include cinnamon, clove oils (Bullerman et al., 1977), coriander (Delaquis et al., 2002), satureja (Ghannadi, 2002), thyme (Lataoui and TantaouiElaraki, 1994), sage (Shelef et al., 1984), basil (Suppakul et al., 2003), rosemary (Del Campo et al., 2000), mint (Tassou et al., 2000), oregano (Skandamis and Nychas, 2001) and garlic (Harris et al., 2001). Essential oils are hydrophobic and their primary site of toxicity to microorganisms is the membrane. They accumulate in the lipid bilayer according to a partition coefficient specific to the applied compound, which leads to disruption of the membrane structure and function (Helander et al., 1998). The antimicrobial action of essential oils has been discussed and it is thought that the effect may be due to the impairment of a variety of enzyme systems, including those involved in energy production and structural component synthesis (Tassou et al., 2000). In particular, the addition of mint (Mentha piperita) essential oil caused an in vitro reduction of the total viable counts of S. aureus by about 6–7 logs and of Salmonella Enteritidis by about 3 logs (Tassou et al., 2000). A rosemary extract (Oxy’less), commercially exploited as an antioxidant of lipids in foods, inhibited the growth of some Grampositive bacteria (Leuconostoc mesenteroides, Listeria monocytogenes, S. aureus) as well as E. coli, S. enteritidis, Erwinia corotowora, yeasts Rhodotorula glutinis and Cryptococcus laurentii (Del Campo et al., 2000). Although garlic has been used for its medicinal properties for thousands of years, investigations into its mode of action are recent. The antibacterial

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials Table 12.1

311

Natural plant extracts in different foods

Plant extract

Food

Benefit

Clove, cinnamon

Soft cheese

Thyme

Mozarella cheese

Antimicrobial

Oregano, clove, basil

Fresh meat (solid or minced meat)

Antimicrobial

Sage Mint

References Smith-Palmer et al. (2001) Menon and Garg (2001) Skandamis et al. (2002a) Menon and Garg (2001)

Meat products Paté

Antimicrobial

Tassou et al. (1996)

Basil, bay, cinnamon Clove, lemongrass Oregano, marjoram

Cod fillets Salmon

Antimicrobial

Mejholm and Dalgaard (2002)

Sage, thyme Mint, oregano Basil, sage

Salad dressings Tzatziki

Antimicrobial

Tassou et al. (1996) Skandamis et al. (2001)

Adopted and modified according to Nychas, G.J.E, Tassou, C.C. and Skandamis, P.N.: Making the most of herbs, spices and their active components (in Chapter 10, Skandamis, P.N. Agricultural University of Athens, Greece modified from Table 5 – Application of essential oils in different food).

activity of garlic is well documented (Harris et al., 2001) and is widely attributed to allicin. It has also been found that garlic exerts a differential inhibition between beneficial intestinal microflora and potentially harmful enterobacteriae (Rees et al., 1993). The differing compositions of bacterial membranes and their permeability to allicin could be the cause (Miron et al., 2000). Garlic is often used in food/meat products to increase their shelf-life and to decrease the possibility of food poisoning and the spoilage of processed foods (Kumar and Berwal, 1998). Burt and Reinders (2003) suggested that essential oils of thyme and oregano, particularly when enhanced by an agar stabiliser, may be effective in reducing or preventing the growth of E. coli O157 : H7 in foods. Oregano is perhaps the most frequently tested plant extract in food ecosystems (Paster et al., 1990, 1995; Skandamis and Nychas, 2001, Skandamis et al., 2002a). Oregano essential oil: spoilage bacteria controlling agent in meat In spite of the majority of essential oils being classified as GRAS (Kabara, 1991), their use as preservatives in foods is often self limiting owing to negative flavour considerations, where effective antimicrobial doses may exceed organoleptically acceptable threshold levels. Therefore the most

© Woodhead Publishing Limited, 2011

312

Processed meats

important criterion for selecting these meat system additives is to gauge the minimum effective inhibitory concentration required to achieve the desired antimicrobial effect, while still maintaining sensory acceptability (Lambert et al., 2001). Oregano (Origanum vulgare) belongs to the family Lamiacae and the genus Origanum. It is native to Europe, the Mediterranean region and southern and central Asia. Containing phenolic acids and flavonoids, its components are carvacrol, thymol, limonene, pimene, ocineme and carophyllene. The most common means of extracting its essential oils, is stem distilled extraction (Skandamis and Nychas, 2001). Lambert et al. (2001) reported that oregano essential oil (OEO), containing the active compounds thymol and carvacrol (575 MIC/mg OEO), inhibited S. aureus and Ps. areuginosa (1648 MIC/mg OEO) by disrupting the integrity of the bacterial membrane. This damage further impacts upon pH homeostasis and the equilibrium of inorganic ions within the bacterial cells. This is significant as S. aureus and Pseudomonas spp. are spoilage microflora often associated with meat processing (Nychas and Arkoudelos, 1990). MAP has gained considerable popularity as a method of effective food preservation. The combination of carbon dioxide, nitrogen and oxygen in MAP packs is capable of suppressing the aerobic spoilage flora of meat. To date, most efforts to determine spoilage by chemical or biochemical means have generated questionable results when applied. This is probably due to measurements being influenced by the packaging method employed, as well as by the use of preservatives, including essential oils (Skandamis and Nychas, 2001). These authors tested OEO in minced meat which had been packed in MAP, and found that OEO delayed microbial growth and suppressed the final counts of spoilage bacteria. It also caused a pronounced alteration in the physico-chemical properties of the minced meat. Tests have shown that S. Typhimurium survives in meat samples without OEO under all storage conditions. When OEO was added at a concentration of 0.8% (v/w) OEO, the test samples showed an initial reduction of 1–2 log10 cfu/g on S. Typhimurium (Skandamis et al., 2002a). In the case of L. monocytogenes, a similar dose of OEO (0.8% v/w) produced an initial reduction in bacterial numbers (approximately 2 to 3 log10 decrease) in meat samples. This was the most obvious change under all the vacuum packed and MAP conditions which were assessed (Skandamis et al., 2002a). The availability of oxygen affects also the antimicrobial efficacy of the oil. Paster et al. (1990, 1995) observed that the antimicrobial activity of OEO on S. aureus and S. Enteritidis was greatly enhanced when these organisms were incubated under microaerobic or anaerobic conditions. Under such conditions (low oxygen balance), oxidative changes in the essential oils are minimised. OEO was also more effective in a vacuum and in an atmosphere of 40% CO2 : 30% O2 : 30% N2, when impermeable packing films were compared with highly permeable bags under aerobic conditions allowing high levels of oxygen within the packs (Tsigarida et al., 2000; Skandamis et al.,

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

313

2002a). The antimicrobial effect of oregano in fish samples was also described. Raw fish samples treated with oregano and inoculated with S. aureus and S. Enteritidis were stored under MAP (40% CO2, 30% O2 and 30% N2 or air at 0, 1 °C). The treatment exerted bacteriostatic and bactericidal effects on both pathogens as well as on the autochtonous flora. Inhibition of Shewanella putrefaciens and Photobacterium phosphoreum was also noted when fish samples were treated with oregano (Tassou et al., 1996; Mejholm and Dalgaard, 2002). However, using microbial analysis alone as a spoilage index, may misrepresent the effect of a barrier such as OEO on spoilage. Further research on the benefits of OEO in food preservation is needed to examine both the microbiological and physico-chemical aspects of preservation (Skandamis and Nychas 2001, Skandamis et al., 2002a,b).

12.3 Combined effect of natural antimicrobials and/or other barriers The application of bio-protective cultures and/or their bacteriocins involving plant extracts has come to be considered as a natural means of enhancing preservation. As mentioned above (page 309), some antimicrobials are of limited efficacy because of intrinsic factors such as low pH or salt levels (Jofré et al., 2009). In order to improve the potency of these natural plant extracts, they have been assessed in combination with other preservatives. For example, a cocktail of plant extracts in combination with bacteriocins or several antimicrobials (bacteriocins), or antimicrobial substances under high-pressure. Pol and Smid (1999) reduced viable counts of L. monocytogenes and B. cereus under laboratory conditions by combining nisin with sublethal doses of carvacrol. This indicates a synergistic effect between nisin and carvacrol. By combining nisin with plant essential oils, the restrictions in the use of nisin as a food preservative could be expanded or involved. Bacteriocins have been found to react with temperature and atmosphere to enhance their effect against L. monocytogenes. However, while viable cells were reduced, single colonies were still detected when using this approach (Szabo and Cahill, 1998). One of the more challenging aspects of such studies is the chemical complexity of these systems and the additional impacts of controlled gaseous environments on their reactions. Under controlled laboratory conditions, the synergistic combination effect has so far been successful only in experiments on milk or cheese model systems. These model systems have shown a synergistic efficacy in the inactivation of S. aureus by combining bacteriocin-producing LAB with the high pressure treatment of raw milk cheese (Arqués et al., 2005). Nitrates are commonly used to prevent clostridial growth in meat; but safety concerns regarding the presence of nitrites have prompted the seeking out of alternative possibilities. Nisin, in combination with lower levels of nitrate, has been shown to prevent the growth of Clostridium spp. (Rayman et al., 1983). Fermented

© Woodhead Publishing Limited, 2011

314

Processed meats

sausage technology involves a sequence of barriers which develop during the overall ripening process. A variety of fermented sausages are manufactured, based on the concept of pH and/or water activity reduction. In low acid fermented sausage, the absence of high acidification may be balanced by the application of additional barriers such as bacteriocins or high hydrostatic pressure (HHP). The application of a HHP treatment alone, or in combination with Ent A and B produced by E. faecium CTC 492, has been reported as necessary for decreasing levels of pathogens such as Salmonella and L. monocytogenes and reducing cell number to <1 log cfu/g at the end of storage (Jofré et al., 2009). Paster et al. (1999) reported that treatment with nisin, combined with small concentrations of propionic acid, might prevent mould damage in certain foods. Pulse electric field (PEF) is a non-thermal preservation method used mainly in liquid foods to inactivate microorganisms. PEF damages the cell membranes of microorganisms and nisin disrupts cell membrane integrity. Thus a combination of PEF and nisin represents a barrier for the survival of L. innocua, e.g. in whole eggs (Calderón-Miranda et al., 1999). PEF followed by nisin treatment also resulted in a reduction of 5.2 log10 cfu/ml of Micrococcus luteus as an indicator organism, in comparison to a reduction of 4.9 log10 which was obtained when nisin treatment was followed by PEF (Dutrex et al., 2000). The bactericidal effect of nisin alone can decrease viable cells of M. luteus by 1.4 log10 and treatment with PEF (50 pulsed at 33 kV/cm) has resulted in a reduction of 2.4 log10 cfu/g. Thomas and Isak (2007) investigated the combined effect of nisin with natural extracts of the herb rosemary (Rosmarinus officinalis), which contains high levels of antioxidant phenolic diterpenes and low levels of flavour compounds such as essentials oils. In vitro testing demonstrated such a combination to be synergistic. The rosemary extracts enhanced both the cidal and static antibacterial activities of nisin against Gram-positive bacteria. The synergistic effect was demonstrated against L. monocytogenes and B. cereus in vitro in chilled, pasteurised food models such as meat or cheese pasta sauces. Solomakos et al. (2008) tested the combined effect of thyme essential oil and nisin in minced beef which had been experimentally contamined with L. monocytogenes (104 cfu/g) during its refrigerated storage. They found that the most efficient treatment was the combination of thyme EO at 0.6% with nisin at 1000 IU/g. This combined dose decreased the population of L. monocytogenes below the official limit, set by the European Union at 2 log cfu/g during storage at 4 °C. However, the treatment of minced beef with thyme EO at 0.6%, showed stronger inhibitory activity against L. monocytogenes than treatment with nisin at 500 or 1000 IU/g. The combined effect of the enterocin-producing strain E. faecium CCM 4231 in conjunction with sage was applied in rabbit husbandry to test the antimicrobial and imunomodulatory effect (Szabóová et al., 2008b,c). The meat quality was also evaluated and no negative effects were found. Synbiotics are another effective combination representing a combination of a microbial food

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

315

supplement (probiotic) and a prebiotic (the most frequently used are fructo-oligo-saccharides). Prebiotics form the substrate for probiotics which then act to increase survival/activity in the host organisms, while stimulating the indigenous beneficial bacteria (Information Store FST Bulletin, 2007; www.foodsciencecentral.com/fsc/ixid14833).

12.4 Food grade sanitisers: natural adjuncts as indirect sanitisers There are three ways in which the growth of foodborne microorganisms can be inhibited: biological, chemical and physical. Among the chemical means, hypochlorites are commonly used as sanitising agents to reduce microbial populations on fresh products (Escudero et al., 1999). Vinegar and lemon juice, which naturally contain acetic and citric acids, are used as flavouring and acidifying liquids for vegetable salads and may be considered as an alternative disinfectant for removing, or at least reducing, pathogens which present a health risk to consumers. Commercially available Bioquell is a low temperature, residue-free biodecontamination technology acting against bacteria, viruses and fungi with links to L. monocytogenes, Salmonella sp., S. aureus, Enterobacteriae, Clostridium sp., Pseudomonas sp., Aspergillus sp. Star-San is a no-rinse, odourless and flavourless food grade sanitiser which is recommended for practical usage. Wise Food Processing supply a Colloidal Liquid Clearing Concentrate designed for use in all food and beverage processing areas. Its base is a non-hazardous plant-derived cleaning solution which does not contain bacteria or enzymes. Wise Food Processing also supply a food-grade penetrating lubricant based on a proprietary and patented anti-oxidant, antiwear and cold flow technology. Standard ingredients are non-GMO agricultural vegetable oils. When acidic and alkaline sanitisers were tested for inhibition of the growth of S. aureus, disinfectants were found to be more effective than those sanitisers already in 1% concentration. However, E. coli or pseudomonads were inhibited by both disinfectants and sanitisers. Some studies referred to the use of natural additives (bacteriocin or herbal extracts) for this purpose. Where enterocins were used, Ent M, produced by E. faecium AL41 and Ent EK13, produced by E. faecium EK13 (CCM7419) were found to be successful against meat spoilage and food microflora (in Final Report, December 2005 EU project with the acronym Tradisausage, QLK1CT-2002-02240, www.clermont.inra.fr/tradisausage/index.htm). It was found difficult to obtain a disinfectant which is effective on both spoilage and pathogenic bacteria without destroying the technological flora. Essential oils, for example. from Satureja thymbra, may prove good disinfectants, but only if low levels of pathogenic bacteria are present during the manufacture of traditional sausages (www.clermont.inra.fr/tradisausage/index.htm).

© Woodhead Publishing Limited, 2011

316

Processed meats

12.5 Advantages of natural antimicrobials and new perspectives for their application All investigation and analysis of natural antimicrobials are directed towards their practical applications. The principal advantage is that they are natural substances, and in the case of plant extracts, probiotics and bacteriocins, do not leave unwanted residues or have an adverse influence on the organoleptic acceptability of the final meat products. ‘Functional food’ as a marketing term was initiated in Japan in the late 1980s and was used to describe foods fortified with ingredients capable of producing health benefits. During the 2000s, specific functional food products have been scientifically proved to benefit the health and well-being of consumers. Proposed functional foods in Europe include 60% of dairy products, 25% of fat-based spreads, 10% of bakery and cereal products and 5% of drinks (Young, 2000). This concept is becoming increasingly popular with consumers who have a heightened awareness of the link between health, nutrition and diet (Stanton et al., 2001). Current definitions of what constitutes a functional food vary considerably as a result of the rapid worldwide growth of the area in recent years. Functional food may be simply defined as food processed to offer disease-preventing and/or healthpromoting benefits, in addition to its nutritive value. The term often overlaps with nutraceuticals, medical foods and designer foods. In 1991, the concept of foods for specified health use (FOSHU) was established in Japan (Arihara, 2006). Typical functional ingredients used in FOSHU products are: probiotics – lactic acid bacteria, soy proteins, peptides, amino acids – and prebiotics – oligosacharides, dietary fibres, vitamins and minerals (Sanders, 1998; Arihara, 2006; Turner, 2009). The Japan company Ajinomoto, which celebrated its centenary in 2009, offers evidence of the fact that humans have searched for natural means of improving food for centuries. This company has described the twenty-first century as the century of amino acids. The Ajinomoto group believes that amino acids hold the key to the future development of food and nutritional products in the form of functional foods or functional food additives. Ajinomoto will continue to be the world’s premier company committed to improving health, nutrition and quality of life through the creation and utilisation of amino acids. For example, aspartame is approximately 200 times sweeter than sugar and is utilised as a stable sweetener in many foods. Many common foods, including meat, contain the amino acids l-aspartic acid and l-phenylalanine, from which dipeptide aspartame is composed. Phenylalanine is considered essential for effective bodily function and good health. Ajinomoto AminoScience has petitioned for GRAS certification for five amino acids which will allow them a consequent broader use of amino acids in categories promoting a functional benefit (Turner, 2009). However, owing to recent advances, this range of new additives could be extended to encompass bacteriocin-producing

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

317

starter cultures, some of which also possess probiotic qualities (Tables 12.2 and 12.3). Perhaps the greatest challenge facing such emerging functional adjuncts is a better understanding of their overall function and general mechanisms within a meat system, and the generation of a greater consumer awareness

Table 12.2

Bacteria used as commercial starter cultures in meat products

Commercial strains

Products

Lb. plantarum

Dry sausages (pork, beef) Semi-dry sausage (beef)

Lb. brevis Lb. curvatus Lb. sakei* Pediococcus acidilactici

Leuconostoc carnosum* Lb. plantarum† Staphylococcus carnosus† Lb. pentosus Lb. casei Lb. alimentarius Ped. pentosaceus S. xylosus

Micrococcus varians Debaromyces hansenii Candida famata Penicillium nalgiovense P.camamabertii/ candicum

Fermented sausages Vacuum packed meat MAP meat product Raw sausages, frankfurters Hamburgers, MAP cooked Ham Vacuum packed meat MAP meat product Sliceable, spreadable Sausages, cooked ham Minced, boiling meats Fermented sausages

Some effects or protection

Antilisterial

Shelf-life extenders

Antilisterial Acceleration of drying process

Fermented sausages

Curing process Complementation Colour Stabilisation Flavour, aroma bouquet

Fermented sausages

Flavour, aroma bouquet

Fermented sausages

Flavour, aroma bouquet

Source: Charlier C, Cretenet M, Even S and Le Loir Y (2009) Interactions between Staphylococcus aureus and lactic acid bacteria: An old story with new perspectives. Int J Food Microbiology 131, 30–39. * Lb. sakei B-2, Lc. carnosum 4010 (Bactoferm F-Lc, Christian Hansen (Hoershom, Denmark), Producing pediocin and sakacin, Aymerich et al. (2008). † Danisco (Copenhagen, Denmark), Aymerich et al. (2008), Kolozyn-Krajewska and Dolatowski (2009).

© Woodhead Publishing Limited, 2011

318

Processed meats

Table 12.3 Potential new strains (bacteriocin-producing, probiotic) used as starter cultures/additives Potential novel strains

Products

Effects

Staphylococcus xylosus

Fermented salami

S. eqourum

Chorizo

Antimicrobial, stability Extender Antimicrobial

Lauková et al. (2010) (www.clermont.inra.fr/tradisausage/index.htm).

of their potential health and safety benefits in the manufacture of wholesome and convenient meat products. The benefit provided by functional starter cultures (FSC) is the production of a safer and better tasting product through a more reliable production process (Léroy et al., 2006). The use of selected strains to produce interesting aroma components could lead to better tasting sausages and a reduction of the current ripening times. However, it is necessary to take into account knowledge of the raw materials, technology and sensory quality. Starters should not possess undesirable characteristics (formation of toxic compounds such as biogenic amines) or excessive quantities of acetic acid or acetoin. The production of acetoin is stimulated by low pH and low sugar availability at the end of the ripening period and may cause a dairy product odour in fermented sausages (García-Varona et al., 2000). It is logical and commercially viable to promote FSC for safer products, as they offer considerable food safety advantages without the risks for human health which arise from toxicological side effects (Cleveland et al., 2001). In situ bacteriocin production does not generally lead to organoleptic or flavour imperfections (Coffey et al., 1998). Competition among bacteriocin producers is advantageous if a more reliable production process is to be achieved. Applications which use new starter cultures can improve the competitiveness of the starter and lead to a more controlled fermentation process (Léroy et al., 2006). The use of strains with antioxidant properties due to catalase or superoxide dismutase (e.g. S. carnosus) may help to inhibit lipid oxidation and to prevent deterioration of colour and texture as well as the formation of toxic compounds (Barriére et al., 2001). Antioxidants are classified as compounds capable of delaying, retarding, or preventing the auto-oxidation processes (Shahidi and Wanasundara, 1992). McCarthy et al. (2001) tested the antioxidant activities of plant extracts such as rosemary, ginseng or sage which were evaluated in pork patties prepared from both fresh and previously frozen pork. The ingredients were found to be more effective in reducing lipid oxidation in patties made from previously frozen pork. Rosemary and sage were identified as the most effective antioxidants with decreasing potency. Bacteriocin-producing starter cultures offer a technological advantage as they replace part of the preservative action and reduce the need for chemi-

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

319

cal or related additive interventions. The use of preservative strains capable of generating nitrosylated derivates of myoglobin, i.e. converting brown metmyoglobin into red myoglobin derivates, may be used to assist in colour formation during the curing process (Moller et al., 2003). The use of strains which lead to accelerated ripening in fermented sausages may also yield technological advantages that result in a reduction of storage (i.e. drying/ ripening) times and thus an improvement in profit margins and competitiveness (Fernández et al., 2000). A revolutionary process for the acceleration of drying is the QDS (Quick Dry Slice) process which is used in sliced meat products after the fermentation step and prior to the final lengthy drying phase. This innovative process greatly reduces the total processing time, eliminates long periods of time in the drying chamber, simplifies the production process and results in significantly improved energy efficiency (http://www.metalquimia.com/productes.php?idm=3&subpagina=20). The manufacture of probiotic meat products presents more difficulty than that of other products. Probiotic bacteria which can be used in the manufacturing of fermented meat products must be capable of surviving in the conditions found in those fermented products; they should also take a dominant position in respect to other microorganisms found in the finished product and the product must maintain its sensory characteristics. Probiotic bacteria need to be added as the filling is being prepared. During the ripening process they should produce a strong defence mechanism as atypical bacteria distinct from the natural microbiota present in raw fermented sausage (Kolozyn-Krajewska and Dolatowski, 2009). Genetically modified organisms (GMO) in food are frequently discussed by both scientists and the public – the term GM probiotics (Ahmed, 2003) first appeared in relation to the possibility of their presence in foods. The term GMO defines organisms whose genetic material has been altered using genetic engineering techniques. GMO are used in the production of insulin to treat diabetes (Walsh, 2005). However, only a few lactic acid probiotic bacteria have been modified by recombinant-DNA technology, due to consumer resistance to their introduction into markets, especially in Europe. Examples are those strains with increased proteolytic properties which are used in the cheese industry (Joutsjoki 1999) and in the construction of bacteriophage-resistant strains (Moineau, 1999). However, public acceptance of GM foods and ingredients is not uniform (Ahmed, 2003). The EU introduced a de facto moratorium in 1998 on the production of GM foods. A practical example of the protection or prolongation of stability in fermented meat products is S. xylosus which was used experimentally in Slovak salami Start. It is a bacteriocin-producing probiotic strain which is isolated from the starter culture for free fermented sausage (Lauková et al., 2010) and was added to the meat mass in the concentration 108 cfu before adding its filling. It survived well in salami and no influence on water activity, pH or the sensory quality of the product was noted.

© Woodhead Publishing Limited, 2011

320

Processed meats

Another example was Staphylococcus equorum, used in the production of chorizo in Portugal and France to produce fermented meat products as starter cultures. A decrease in listeriae and Gram-negatives was observed (www.clermont.inra.fr/tradisausage/index.htm) with a consequent improvement in the hygenic quality of the products. We are now in the post-genomic age of microbiology and many microorganisms employed in commercial food processing have been sequenced. The availability of the genomes of many food pathogens and spoilage bacteria have opened up new possibilities for the controlled design of new antimicrobials to target the essential functions of these problematic bacteria. By harnessing the wealth of information on improved culture performance and activity, the safety, quality and composition of the food supply has been improved through natural intervention for control of meat spoilage pathogens. Bacteria are a daunting but rewarding challenge to the industry (Ross et al., 2002). Practical recommendations associated with food processing, especially in the manufacture of meat products, were among the conclusions listed in Hygienic Practices of Traditional Fermented Sausage developed in the EU project Tradisausage (www.clermont.inra.fr/ tradisausage/index.htm).

12.6 References acnfp (1996) report on Enterococcus faecium, strain K77D. In MAFF Advisory Committee on Novel Foods and Processes, report, Ergon House c/o Nobe House, 17 Smith Square, London SW1, 3JR, United Kingdom. ahmed fe (2003) Genetically modified probiotics in foods. Trends in Biotechnol 21, 491–497. ananou s, maqueda m, martínez-bueno m, gálvez a and valdivia a (2005) Control of Staphylococcus aureus in sausages by enterocin AS-48. Meat Sci 71, 549–556. doi: 10.1016/j.meatsci.2005.04.039 arihara k (2006) Strategies for designing novel functional meat products. Meat Sci 74, 219–229. arihara k, ota h, itoh m, kondo y, sameshima t, yamanaka h, akimoto m, kanai s and miki t (1998) Lactobacillus acidophilus group lactic acid bacteria applied to meat fermentation. J Food Sci 63, 544–547. arqués jl, rodríguez e, gaya p, medina m, guamis b and nunéz m (2005) Inactivation of Staphylococcus aureus in raw milk cheese by combinations of high-pressure treatments and bacteriocin-producing lactic acid bacteria. J Appl Microbiol 98, 254–260. aymerich t, holo h, havarstein ls, hugas m, garriga m and nes if (1996) Biochemical and genetic characterization of enterocin A from Enterococcus faecium, a new antilisterial bacteriocin in the pediocin family of bacteriocins. Appl Environ Microbiol 62, 1676–1682. aymerich t, artigas mg, garriga m, monfort jm and hugas m (2000) Effect of sausage ingredients and additives on the production of enterocins A and B by Enterococcus faecium CTC 492. Optimization of in vivo production and antilisterial effect in dry fermented sausages. J Appl Microbiol 88, 686–694.

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

321

aymerich t, martín b, garriga m and hugas m (2003) Microbial quality and direct PCR identification of lactic acid bacteia and non-pathogenic staphylococci from artisanal low acid sausages. Appl Environ Microbiol 69, 4583–4594. aymerich t, picouet pa and monfort jm (2008) Decontamination technologies for meat products. Meat Sci 78, 114–129. doi: 10.1016/j.meatsci.2007.07.007 bagamboula cf, uyttendaele m and debevere j (2003) Antimicrobial effect of spices and herbs on Shigella sonnei and Shigella flexneri. J Food Prot 66, 668–673. barriére c, centeno d, lebert a, léroy-sétrin s, berdagué jl and talon r (2001) Roles of superoxide dismutase and catalase of Staphylococcus xylosus in the inhibition of linoleic acid oxidation. FEMS Microbiol Lett 201, 181–185. bellono g a, mangiagle l, nicastro l and frigerio l (1980) A controlled doubleblind study of SF68 strain as a new biological preparation for the treatment of diarrhoea in pediatrics. Curr Ther Res 28, 927–934. berufsgenossenschaft der chemischen industrie (1995) In safety and health promotion aspects of enterococci – a brochure FAIR-CT97-3078 – enterococci in Food Fermentations. Functional and Safety Aspects. booth mc, bogie co, sahl hg, siezen rj, hatter kl and gilmore ms (1996) Structural analysis and proteolytic activation of Enterococcus faecalis cytolysin, a novel antibiotic. Mol Microbiol 21, 1175–1184. boziaris is and adams mr (2001) Temperature shock, injury and transient sensitivity to Nisin in Gram negatives. J Appl Microbiol 91, 715–724. budde bb, hornbaek t, jacobsen t, barkholt v and granly koch a (2003) Leuconostoc carnosum 4010 has the potential for use as a protective culture for vacuum-packed meats: culture isolation, bacteriocin identification, and meat application experiments. Int J Food Microbiol 83, 171–184. doi: 10.1016-S01681605(02)00364-1 bullerman lb, lieu fy and seier sa (1977) Inhibition of growth and aflatoxin production by cinnamon and clove oils. Cinnamic aldehyde and eugenol. J Food Prot 42, 1107–1109. burt sa and reinders rd (2003) Antibacterial activity of selected plant essential oils against Escherichia coli O157:H7. Lett Appl Microbiol, 36, 162–167. calderón-miranda ml, barbosa-cánovas v and swanson bg (1999) Inactivation of Listeria innocua in liquid whole egg by pulsed electric fields and Nisin. Int J Food Microbiol 51, 7–17. callewaert r, hugas m and de vuyst l (2000) Competitiveness and bacteriocin production of Enterococci in the production of Spanish-style dry fermented sausages. Int J Food Microbiol 57, 33–42. casaus p, nilsen t, cintas lm, nes if, hernández pe and holo h (1997) Enterocin B, a new bacteriocin from Enterococcus faecium T136 which can act synergistically with enterocin A. Microbiology 143, 2287–2294. charlier c, cretenet m, even s and le loir y (2009) Interactions between Staphylococcus aureus and lactic acid bacteria: an old story with new perspectives. Int J Food Microbiology 131, 30–39. chen h and hoover dg (2003) Bacteriocins and their food applications. Comp Rev Food Sci Food Safety 2, 82–100. chin se, liu w, strorkson jm, ha yl and pariza mw (1992) Dietary sources of conjugated dienoic isomars of linoleic acid, a newly recognized class of anti-carcinogens. J Food Comp Anal 5, 185–197. chung, kt, dickson js and crouse jd (1989) Effect of nisin on growth of bacteria attached to meat. Appl Environ Microbiol 55, 1329–1333. cintas lm, casaus p, havarstein ls, hernández pe and nes if (1997) Biochemical and genetic characterization of enterocin P, a novel sec-dependent bacteriocin from Enterococcus faecium P13 with a broad antimicrobial spectrum. Appl Environ Microbiol 63, 4321–4330.

© Woodhead Publishing Limited, 2011

322

Processed meats

cintas lm, casaus p, holo h, hernández pe, nes if and havarstein lv (1998) Enterocins L50A and L50B, two novel bacteriocins from Enterococcus faecium L50, are related to staphylococcal hemolysins. J Bacteriol 180, 1988–1994. cintas lm, casaus p, herranz c, havarstein lv, holo h, hernández pe and nes if (2000) Biochemical and genetic evidence that Enterococcus faecium L50 produces enterocins L50A and L50B, the sec-dependent enterocin P, and a novel bacteriocin secreted without an N-terminal extension termed enterocin Q. J Bacteriol 182, 6806–6814. cleveland j, montville tj, nes if and chikindas ml (2001) Bacteriocins: safe, natural antimicrobials for food presrvation. Int J Food Microbiol 71, 1–20. coffey a, ryan m, ross rp, hill c, arendt e and schwarz g (1998) Use of a broadhost-range bacteriocin-producing Lactococcus lactis transconjugant as an alternative starter salami manufacture. Int J Food Microbiol 43, 231–235. conner de (1993) Naturally occurring compounds, in P Davidson & AL Brenen (Eds), Antimicrobials in Foods (pp. 441–468), New York, Marcel Dekker. coppola r, iorizzo m, saotta r, sorrentino e and grazia l (1997) Characterization of micrococci and staphylococci isolated from soppressata molisana, a Southern Italy fermented sausage. Food Microbiol 14, 47–53. cutter cn and siragusa gr (1994) Decontamination of beef carcass tissue with Nisin using a pilot scale model carcass washer. Food Microbiol 11, 481–489. de vuyst l and vandamme e j (1994) Bacteriocins of Lactic Acid Bacteria: Microbiology, Genetics and Applications. Blackie Academic and Profesional, London. de vuyst l, callewaert r and pot b (1996) Characterization of the antagonistic activity of Lactobacillus amylovorus DCE471 and large scale isolation of its bacteriocin amylovorin L471. System Appl Microbiol 19, 9–20. de vuyst l, falony g and leroy f (2008) Probiotics in fermented sausages. Meat Sci 80, 75–78. del campo j, amiot mj and nguyen-the ch (2000) Antimicrobial effect of rosemary extracts. J Food Prot 63, 1359–1368. delaquis pj, stanich k, girard b and mazza g (2002) Antimicrobial activity of individual and mixed fractions of dill, cilantro, coriander and eucalyptus essential oils. Int J Food Microbiol 74, 101–109. delves-broughton j, blackburn p, evans rj and hugenholtz j (1996) Applications of the bacteriocin, nisin. Ant van Leeuwenh 69, 193–202. dicks lmt, mellet fd and hoffman lc (2004) Use of bacteriocin-producing starter cultures of Lactobacillus plantarum and curvatus in production of ostrich meat salami. Meat Sci 66, 703–708. drider d, fimland g, héchard y, mcmullen lm and prévost h (2006) The continuing story of class IIa bacteriocins. Microbiol Mol Biol Rev 70, 564–582. doi: 10.1128/ MMBR.00016-05 dutreux n, notermans s, góngora-nieto mm, barbosa-cánovas gv and swanson bg (2000). Effects of combined exposure of Micrococcus luteus to nisin and pulsed electric fields. Int J Food Microbiol 60, 147–152. eec (1983). EEC Commission Directive 83/463/EEC. efsa (2004) In Summary Report of EFSA Scientific Colloquium 2, 13–14 December, Brussel, Belgium, pp. 1–117, ISSN 1830-4737. elliason dj and tatini sr (1999) Enhanced inactivation of Salmonella typhimurium and verotoxigenic Escherichia coli by nisin at 6.5 °C. Food Microbiol 16, 257–267. erkkilä s and petäjä e (2000) Screening of commercial meat starter cultures at low pH and in the presence of bile salts for potential probiotic use. Meat Sci 55, 297–300. erkkilä s, suihko ml, eerola s, petäjä e and mattila-sandholm t (2001) Dry sausage fermented by Lactobacillus rhamnosus strains. Int J Food Microbiol 64, 205–210.

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

323

escudero em, velazquez l, di genaro sm and de guzmán sam (1999) Effectiveness of various disinfectants in the elimination of Yersinia enterocolitica on fresh lettuce. J Food Prot 62, 665–669. essid i, ismail hb, ahmed sbh, ghedamsi r and hassouna m (2007) Characterization and technological properties of Staphylococcus xylosus strains isolated from a Tunisian traditional salted meat. Meat Sci 77, 204–212. doi: 10.1016/j. meatsc.2007.03.003 european commission (2004) List of the authorized additives in feeding stuffs published in application of Article 9th (b) of Council Directive 70/524/EEC concerning additives in feeding stuffs. Official J Euro Union C50. fao/who (2001) Health and nutritional properties of probiotics in food including powder milk with live lactic acid bacteria – Joint Food and Agricultural Organization of the United nations and World Health Organization Expert Consultation Report, Córdoba, Argentina. http://www.who.int/foodsafety/publications/fs_management/probiotics/en/index.html fao/who (2002) Guidelines for the evaluation of probiotics in food – Joint Food and Agricultural Organization of the United nations and World Health Organization Working Group Meeting report, london Ontario, Canada. http://www.who.int/ foodsafety/publications/fs_management/probiotics2/en/index.html felix jv, papathanasopoulos ma, smith aa, van holy a and hastings jw (1994) Characterization of leucocin B-Ta11a: a bacteriocin from Leuconostoc carnosum Ta11a isolated from meat. Curr Microbiol 29, 207–212. fernández m, ordónez ja, bruna jm, herranz b and de la hoz l (2000) Accelerated ripening of dry fermented sausages. Trends in Food Sci Technol 11, 201–209. floriano b, ruiz-barbra jl and jimenez-diaz r (1998) Purification and genetic characterization of enterocin I from Enterococcus faecium 6T1a, a novel antilisterial plasmid-encoded bacteriocin which does not belong to the pediocin family of bacteriocins. Appl Environ Microbiol 64, 4883–4890. food and drug administration (1988) http://www.fda.gov/cdrh/oivd/guidance/1171. pdf foulquié-moreno mr, callewaert r, devreese b, van beeumen j and de vuyst l (2003) Isolation and biochemical characterization of enterocins produced by enterococci from different sources. J Appl Microbiol 94, 214–229. foulquié-moreno mr, sarantinopoulos p, tsakalidou e and de vuyst l (2006) The role and application of enterococci in food and health. Int J Food Microbiol 106, 1–24. doi: 10.1016/j.ijfoodmicro.2005.06.026 franz chmap, holzapfel wh and stiles me (1999) Enterococci at the crossroads of food safety? Int J Food Microbiol 47, 1–24. franz chmap, van belkum mj, holzapfel wh, abriouel h and gálvez a (2007) Diversity of enterococcal bacteriocins and their grouping in a new classification scheme. FEMS Microbiol Rev 31, 293–310. doi: 10.1111/j.1574-6976. 2007.00064.x fuller r (1989) Probiotics in man and animals. J Appl Bacteriol 66, 365–378. fuller r and gibson gr (1997) Modification of the intestinal microflora using probiotics and prebiotics. Scand J Gastroenterol 32, 28–31. gálvez a, maqueda m, valdivia e, quesada a and montoya e (1986) Characterization and partial purification of a broad spectrum antibiotic AS-48 produced by Streptococcus faecalis. Can J Microbiol 32, 765–771. gálvez a, lópez rl, abriouel h, valdivia e and omar nb (2008) Application of bacteriocins in the control of food-borne pathogens and spoilage bacteria. Crit Rev Biotechnol 28, 125–152. garcía-verona m, santos em, jaime i and rovira j (2000) Characterisation of Micrococcacae isolated from different varieties of chorizo. Int J Food Microbiol 54, 189–195.

© Woodhead Publishing Limited, 2011

324

Processed meats

ghannadi a (2002) Composition of the essential oil of Satureja hortensis L. seeds from Iran. J Essent Oil Res 14, 35–36. gillor o, nigro lm and riley ma (2005) Genetically engineered bacteriocins and their potential as the next generation of antimicrobials. Cur Pharm Design 11, 1067–1075. giraffa g (2002) Enterococci from foods. FEMS Microbiol Rev 744, 1–9. giraffa g, carminati d and neviani e (1997) Enterococci isolated from dairy products: a review of risks and potential technological use. J Food Prot 60, 732–738. harris jc, cottrell sl, plummer s and lloyd d (2001) Antimicrobial properties of Allium sativum (garlic). Appl Microbiol Biotechnol 57, 282–286. harris lj, fleming hp and klaenhammer tr (1992) Developments in nisin research. Food Res Int 25, 57–66. helander im, alakomi hl, latva-kala k, mattila-sandholm t, pol i, smid ej, gorris lgm and von wright a (1998) Characterisation of the action of selected essential oil components on Gram-negative bacteria. J Agric Food Chem 46, 3590–3595. hellemans a (2003) Consumers fears cancel European GM research. Scientist 17, 52–54. hernández d, cardell e and zárate v (2005) Antimicrobial activity of lactic acid bacteria isolated from Tenerife cheese: initial characterization of plantaricin TF711, a bacteriocin-like substance produced by Lactobacillus plantarum TF711. J Appl Microbiol 99, 77–84. herranz c, mukhopadhyay s, casaus p, martínez jm, rodríguez jm, hernández pe and cintas lm (2001) Enterococcus faecium P21: a strain occurring naturally in dry-fermented sausages producing the class II bacteriocins enterocin A and enterocin B. Food Microbiol 18, 115–131. hudault s, liévin v, bernet-camard mf and servin al (1997) Antagonistic activity exerted in vitro and in vivo by Lactobacillus casei (strain GG) against Salmonella typhimurium C5 infection. Appl Environ Microbiol 63, 513–518. hugas m (1998) Bacteriocinogenic lactic acid bacteria for the bio-preservation of meat and meat products. Meat Sci 49, 139–150. hugas m, pages f, garriga m and monfort jm (1998) Application of the bacteriocinogenic Lactobacillus sakei CTC494 to prevent growth of Listeria in fresh and cooked meat products packed with different atmospheres. Food Microbiol 15, 639–650. hurst a (1981) Nisin. In Perlam D & Laskin AI (Eds) Advances in Applied Microbiology (pp. 85–123), New York, NY, Academic Press. incze k (1998) Dry fermented sausages. Meat Sci 5, 503–513. jack rw, tagg jr and ray b (1995) Bacteriocins of gram-positive bacteria. Microbiol Rev 59, 171–200. jay jm (1996) Prevalence of Listeria spp. in meat and poultry products. Food Control 7, 209–214. jessen b (1995) Starter cultures for meat fermetation. In G. Campbell-Platt & P.E. Cook (Eds), Fermented Meats (pp. 130–154). Glasgow, Blackie Academic & Professional. jofré a, aymerich t and garriga m (2009) Improvement of the food safety of low acid fermented sausages by enterocins A and B and high pressure. Food Control 20, 179–184. doi: 10.1016/j.foodcont.2008.04.001 johnsen l, fimland g, eijsink v and nissen-meyer j (2000) Engineering increased stability in the antimicrobial peptide pediocin PA-1. Appl Environ Microbiol 66, 4798–4802. joutsjoki v (1999) Recombinant Lactococcus starters as a potential source of aditional peptidolytic activity in cheese ripening. J Appl Microbiol 92, 1159–1166. kabara jj (1991) Phenols and chelators, In Food Preservatives, eds Russel NJ and Gould GW (pp. 200–214) London, Blackie.

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

325

kaiser al and montville tj (1996) Purification of the bacteriocin bavaricin MN and characterization of its mode of action against Listeria monocytogenes Scott A cells and lipid vesicles. Appl Environ Microbiol 62, 4529–4535. karapinar m and aktung se (1987) Inhibition of food-borne pathogens by thymol, eugenol, menthol and anethole. Int J Food Microbiol 4, 161–166. klaenhammer tr (1993) Genetics of bacteriocins produced by lactic acid bacteria. FEMS Microbiol Rev 12, 39–86. klinberg td and budde bb (2006) The survival and persistence in the human gastrointestinal tract of five potential probiotic lactobacilli consumed as freeze-dried culture or as probiotic sausage. Int J Food Microbiol 106, 270–285. knudtson lm and hartman pa (1993) Enterococci in pork processing. J Food Prot 56, 6–9. kolozyn-krajewska, d and dolatowski zj (2009) Probiotics in fermented meat products. Acta Sci Pol Technol Aliment, 61–74. kontula p, suihko ml, von wright a and mattila-sandholm t (1999) The effect of lactulose derivates on lactic acid bacteria. J Dairy Sci 82, 249–256. kumar m and berwal js (1998) Sensitivity of food pathogens to garlic. J Appl Microbiol 84, 213–215. lambert rjw, skandamis pn, coote pj and nychas gje (2001) A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. J Appl Microbiol 91, 453–462. lataoui n and tantaoui-elarakia (1994) Individual and combined antibacterial activity of the main components of three thyme essential oils. Riv Ital EPPOS 13, 13–19. lauková a (1995) Inhibition of ruminal staphylococci and enterococci by nisin in vitro. Lett Appl Microbiol 20, 34–36. lauková a (2000) In vitro treatment of different isolates from cattle dung and pig slurry by Nisin. Acta Vet Brno 69, 147–151. lauková a and mareková m (1993) Antimicrobial spectrum of bacteriocin-like substances produced by rumen staphylococci. Folia Microbiol 38, 74–76. lauková a and turek p (2004) Experimental application of bacteriocins during meat products processing. In Proceedings from International Conference on Agrofood Legislation under Conditions of Globalization, High Tatras, pp. 164–168. lauková a, mareková m and javorsky´ p (1993) Detection and antimicrobial spectrum of a bacteriocin-like substance produced by Enterococcus faecium CCM 4231. Lett Appl Microbiol 16, 257–260. lauková a, czikková s, laczková s and turek p (1999a) Use of enterocin CCM4231 to control Listeria monocytogenes in experimentally contaminated dry fermented Hornád salami. Int J Food Microbiol 52, 115–119. lauková a, czikková s, dobránsky t and burdová o (1999b) Inhibition of Listeria monocytogenes and Staphylococcus aureus by enterocin CCM 4231 in milk products. Food Microbiol 16, 93–99. lauková a, guba p, nemcová r and vasilková z (2003a) Reduction of Salmonella in gnotobiotic Japanese quails cause by the enterocin A-producing EK13 strain of Enterococcus faecium. Vet Res Com 27, 275–280. lauková a, turek p, mareková m and nagy j (2003b) Use of ent M, new variant of ent P to control Listeria innocua in experimentally contaminated Gombasek sausage. Arch Lebensmit 54, 25–48. lauková a, strompfová v, skrˇivanová v, volek z, jindrˆ ichová e and marounek m (2006) Bacteriocin-producing strain of Enterococcus faecium EK13 with probiotic character and its application in the digestive tract of rabbits. Biológia, Bratislava 61, 779–782. lauková a, marcinˇ áková m, strompfová v and ouwehand, ac (2008a) Probiotic potential of enterococci isolated from canine feed. Folia Microbiol 53, 84–88.

© Woodhead Publishing Limited, 2011

326

Processed meats

lauková a, sy´cˇevová k and turek p (2008b) Antilisterial effect of enterocins in the practice. Slovak Vet J (in Slovak) 23, 385–387. lauková a, simonová m and strompfová v (2010) Staphylococcus xylosus S03/1M/1/2, a bacteriocin-producing starter culture or additive. Food Control 21, 970– 973. léroy f, verluyten j and de vuyst l (2006) Functional meat starter cultures for improved sausage fermentation. Int J Food Microbiol 106, 270–285. doi: 10.1016/ j.ijfoodmicro.2005.06.027 mahadeo m and tatini sr (1994) The potential use of nisin to control Listeria monocytogenes in poultry. Lett Appl Microbiol 18, 323–326. marcinˇ áková m (2006) Probiotic micro-organisms in the feed and in the digestive tract of animals and their role in the prevention. (in Slovak) PhD thesis, Institute of Animal Physiology Slovak Academy of Sciences, Kosˇice, Slovakia, p. 1–111. marcinˇ áková m, strompfová v, boldižárová k, lauková a and gancarcˇíková s (2004) Effect of potential probiotic activity of Enterococcus faecium EE3 strain against Salmonella infection in Japanese quails. Bull Vet Inst Pulawy 48, 387–390. marcinˇ áková m, strompfová v, boldižárová k, simonová m, lauková a and nad’ p (2005a) Effect of potential probiotic Enterococcus faecium strains on selected microflora in turkeys. Czech J Anim Sci 50, 341–346. marcinˇ áková m, lauková a, simonová m and strompfová v (2006) Inhibitory effect of commercial sanitizers and disinfectants on spoilage bacteria from meat products and workshops. Proceedings of Lectures and Posters – Hygiena Alimentorum XXVI, 25–27 May, Štrbské Pleso, Slovakia, 174–177. mareková m, lauková a, skaugen m and nes i (2007) Isolation and characterization of a new bacteriocin, termed enterocin M, produced by environmental isolate Enterococcus faecium AL 41. J Ind Microbiol Biotechnol 34, 533–537. mäyrä-mäkinen a and suomalainen t (1995) Lactobacillus casei ssp. rhamnosus, bacterial preparations comprising said strain and preparations for the controlling of yeast and moulds. United States Patent No. US 5 378 458. mccarthy tl, kerry jp, kerry jf, lynch pb and buckley dj (2001) Assessment of the antioxidant potential of natural food and plant extracts in fresh and previously frozen pork patties. Meat Sci 57, 177–184. mejholm o and dalgaard p (2002) Antimicrobial effect of essential oils on the seafood spoilage micro-organism Photobacterium phosphoreum in liquid media and fish products. Lett Appl Microbiol 34, 27–31. menon kv and garg sr (2001) Inhibitory effect of clove oil Listeria monocytogenes in meat and cheese. Food Microbiol 18, 647–650. miller kw, schamber r, osmanagaoglu o and ray b (1998) Isolation and characterization of pediocin AcH chimeric protein mutants with altered bactericidal activity. Appl Environ Microbiol 64, 1997–2005. ming x, weber gh, ayres jw and sandine we (1997) Bacteriocins applied to food packaging materials to inhibit Listeria monocytogenes on meats. J Food Sci 62, 413–415. miron t, rabinkov a, mirelmann d, wichek h and weiner l (2000) The mode of action of allicin: its ready permeability through phospholipid membranes may contribute to its biological activity. Biochem Biophys Acta 1463, 20–30. moineau s (1999) Applications of phage resistance in lactic acid bacteria. A van Leeuw Int J Gen Mol Microbiol 76, 377–382. moller jks, jensen js, skibsted lh and knochel s (2003) Microbial formation of nitrite-cured pigment, nitrosylmyoglobin, from metmyoglobin in model systems and smoked fermented sausages by Lactobacillus fermentum strains and a commercial starter culture. European Food Res Technol 216, 463–469.

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

327

morot-bizot s, talon r and leroy-setrin s (2003) Development of specific PCR primers for a rapid and accurate identification of Staphylococcus xylosus, a species used in food fermentation. J Microbiol Meth 55, 279–286. doi: 10.1016/ S0167-7012(03)00159-3 nes if and holo h (2000) Class II antimicrobial peptides from lactic acid bacteria. Biopolymers (Peptide Science) 55, 50–61. nes if, holo h, fimland g, hauge gg and nissen-meyer j (2002) Unmodified peptidebacteriocins (class II) produced by lactic acid bacteria, In McArthur HAI, Wax RG (Eds) (pp. 81–115), Peptide Antibiotics: Discovery, modes of action and applications, Marcel Dekker, New York. nicolosi rj, rogers ej, kritschevsky d, scimeca ja and huth pj (1997) Dietary conjugated linoleic acid reduces plasma lipoproteins and early aortic atherosclerosis in hyperchloesterolemic hamsters. Artery 22, 266–277. nigutová k, morovsky´ m, pristasˇ p, teather rm, holo h and javorsky´ p (2007) Production of enterolysin A by rumen Enterococcus faecalis strain and occurrence of enIA homologues among ruminal Gram-positive cocci. J Appl Microbiol 102, 563–569. doi: 10.1111/j.1365-2672.2006.03068.x nychas gje and arkoudelos js (1990) Staphylococci: their role in fermented sausages. J Appl Bacteriol Symp Suppl 167S-188S. oussalah m, caillet s, saucier l and lacroix m (2006) Antimicrobial effects of selected plant essential oils on the growth of a Pseudomonas putida strain isolated from meat. Meat Sci 73, 236–244. doi: 10.1016/j.meatsci.2005.11.019 ouwehand ac, kirjavainen pv, shortt c and salminen s (1999) Probiotics:mechanisms and established effects. Int Dairy J 9, 43–52. paster n, juven bj, shaaya e, menasherev m, nitzan r, weisslowicz h and ravid u (1990) Inhibitory effect of oregano and thyme essential oils on moulds and foodborne bacteria. Lett Appl Microbiol 11, 33–37. paster n, menasherev m, ravid u and juven b (1995) Antifungal activity of oregano and thyme essential oils applied as fumigants against fungi attacking stored grain. J Food Prot 58, 81–85. paster n, lecong z, menashrov m and shapira r (1999) Possible synergistic effect of Nisin and propionic acid on the growth of the mycotoxigenic fungi Aspergillus parasiticus, Aspergillus ochraceus and Fusarium monifiliforme. J Food Prot 62, 1223–1227. piskoríková, m (2010) Quality and characterisation of existing and new probiotics (EFSA QPS). Proceedings of Regulatory Framework Workshop Health Claim approval of Probiotics in the European Union Issues, barriers, Success Drivers, 18 June, 2010 Kosˇice. pol ie and smid ej (1999) Combined action of nisin and carvacrol on Bacillus cereus and Listeria monocytogenes. Lett Appl Microbiol 29, 166–170. ray b (1992) Nisin of Lactococcus lactis ssp. lactis as food biopreservative, 207–264. In B Ray and MA Daschel (eds) Food Biopreservatives of Microbial Origin. CRC Press Inc, Boca Raton FL. rayman k, malik n and hurst a (1983) Failure of nisin to inhibit outgrowth of Clostridium botulinum in a model cured meat system. Appl Environ Microbiol 46, 1450–1452. rebucci r, sangalli l, fava m, bersani c, cantoni c and baldi a (2007) Evaluation of functional aspects in lactobacillus strains isolated from dry fermented sausages. J Food Qual 30, 187–201. rees lp, minney sf, plummer nt, slater jh and skyrme da (1993) A quantitative assessment of the anti-microbial activity of garlic (Allium sativum). World J Microbiol Biotechnol 9, 303–307. ross rp, morgan s and hill c (2002) Preservation and fermentation: past, present and future. Int J Food Microbiol 79, 3–16.

© Woodhead Publishing Limited, 2011

328

Processed meats

ryan mp, rea mc, hill c and ross rp (1996) An application in Cheddar cheese manufacture for a strain of Lactococcus lactis producing a novel broad spectrum bacteriocin, lacticin 3147. Appl Environ Microbiul 62, 612–619. sabia c, manicardi g, messi p, de niederhausern s and bondi m (2002) Enterocin 416K1, an antilisterial bacteriocin produced by Enterococcus casseliflavus IM 416K1 isolated from Italian sausages. Int J Food Microbiol 75, 163–170. sachindra nm, sakhare pz, yashoda kp and narasimbha rao (2005) Microbial profile of buffalo sausage during processing and storage. Food Control 16, 31–35. doi: 10.1016/j.foodcont.2003.11.002 sahl hg and bierbaum g (1998) Lantibiotics: biosynthesis and biological activities of uniquely modified peptides from gram-positive bacteria. Annu Rev Microbiol 52, 41–79. sanders me (1998) Overview on functional foods: emphasis on probiotic bacteria. Int Dairy J 8, 341–347. saxelin m (1997) Lactobacillus GG – a human probiotic strain with thorough clinical documentation. Food Rev Int 13, 293–313. scanell agm, hill c, buckley dj and arendt ek (1997) Determination of the influence of organic acids and nisin on shelf-life and microbiological safety aspects of fresh pork sausage. J Appl Microbiol 83, 407–412. schillinger u, geisen r and holzapfel wh (1996) Potential of antagonistic microorganisms and bacteriocins for the biological preservation of foods. Trends Food Sci Technol 7, 158–164. schoebitz r, zaror t, léon o and costa m (1999) A bacteriocin from Carnobacterium piscicola for the control of Listeria monocytogenes in vacuum-packaged meat. Food Microbiol 16, 249–255. shahidi f and wanasundara pkjpd (1992) Phenolic antioxidants. CRC Food Sci Nutr 32, 67–103. shelef la, jyothi ek and bulgarelli ma (1984) Growth of enteropathogenic and spoilage bacteria in sage-containing broth and foods. J Food Sci 49, 737–740. simonová m (2006) Probiotic and bacteriocin-producing bacteria and their effect on the physiology of digestion in rabbits. PhD Thesis (in Slovak, summary in English), Institute of Animal Physiology, Slovak Academy of Sciences, 2006, 1–126. simonová m, strompfová v, marcinˇ áková m, lauková a and herich r (2004) Microflora detected in the processing of some meat products. (in Slovak) Proceedings from the international conference Agro-food legislation in the conditions of globalization, High Tatras, Slovakia, 153–156. simonová m, strompfová v, marcinˇ áková m, lauková a, vesterlund s, latorre moratalla m, bover-cid s and vidal-carou c (2006) Characterization of Staphylococcus xylosus and Staphylococcus carnosus isolated from Slovak meat products. Meat Sci 73, 559–564. doi: 10.1016/j.meatsci.2006.02.004 skandamis pn and nychas gje (2001) Effect of oregano essential oil on microbiological and physico-chemical attributes of minced meat stored in air and modified atmospheres. J Appl Microbiol 91, 1202–1205. skandamis pn, tsigarida e and nychas gje (2002a) The effect of oregano essential oil on survival/death of Salmonella typhimurium in meat stored at 5 °C under aerobic, vp/map conditions. Food Microbiol 19, 97–103. skandamis pn, tsigarida e and nychas gje (2002b) Effect of conventional and natural preservatives on the death/survival of Escherichia coli O157:H7 NCTC 12900 in traditional Mediterranean salads: In Joint meeting of the SFAM & DSM ‘Frontiers in Microbial Fermentation and Preservation’, Wageningen, The Netherlands, 9–11 January 2002. skibsted lh (1992) Cured meat products and their oxidative stability. In DE Johnston, MK Knight & DA Ledward (Eds) The Chemistry of Muscle-based Foods (pp. 266–286.) Cambridge, UK: The Royal Society of Chemistry.

© Woodhead Publishing Limited, 2011

Using natural and novel antimicrobials

329

smith-palmer a, stewart j and fyfe l (2001) The potential application of plant essential oils as natural food preservatives in soft cheese. Food Microbiol 18, 463–470. sobrino-lópez a and martín-belloso o (2008) Use of nisin and other bacteriocins for preservation of dairy products. Int Dairy J 18, 329–343. doi: 10.1016/j. idairyj.2007.11.009 solomakos n, govaris a, koidis p and botsoglou n (2008) The antimicrobial effect of thyme essential oil, nisin and their combination against Listeria monocytogenes in minced beef during refrigerated storage. Food Microbiol 25, 120–127. doi: 10.1016/j.fm.2007.07.002 stanton c, gardiner g, meehan h, collins k, fitzgerald g, lynch pb and ross rp (2001) market potential for probiotics. Am J Clin Nutr 73 (suppl), 476S–83S. strompfová v, marcinˇ áková m, simonová m, gancarcˇíková s, jonecová z, sciranková i’, kosˇcˇová j, buleca v, cˇobanová k and lauková a (2006) Enterococcus faecium EK13-an enterocin A-producing strain with probiotic character and its effect in piglets. Anaerobe 12, 242–248. doi: 10.1016/j.anaerobe.2006.09.003 strompfová v and lauková a (2007) In vitro study on bacteriocin production of Enterococci associated with chicks. Anaerobe 13, 228–237. doi: 10.1016/j. anaerobe.2007.07.002 suppakul p, miltz j, sonneveld k and bigger sw (2003) Antimicrobial properties of basil and its possible application in food packaging. J Agric Food Chem 51, 3197–3207. szabo ae and cahill me (1998) The combined affects of modified atmosphere, temperature, Nisin and ALTATM 2341 on the growth of Listeria monocytogenes. Int J Food Microbiol 43, 21–31. szabóová r, chrastinová i’, lauková a, haviarová m, simonová m, strompfová v, faix, sˇ, vasilková z, chrenková m, plachá i, mojto j and rafay j (2008a) Bacteriocin-producing strain Enterococcus faecium CCM4231 and its use in rabbits. Int J Prob Preb 3, 77–82. szabóová r, chrastinová i’, strompfová v, simonová m, vasilková z, lauková a, plachá i, cˇobanová k, chrenková m, mojto j and jurcˇík r (2008b) In Proceedings of the 9th World Rabbit Congress Verona, Italy, 10–13 June (Eds) Xiccato G, Trocino A and Lukefahr SD, 821–825. szabóová r, chrastinová i’, strompfová v, simonová m, vasilková z, lauková a, cˇobanová k, plachá i, chrenková m, mojto j and ondrusˇka i’ (2008c) In Proceedings of the 9th World Rabbit Congress Verona, Italy, 10–13 June (Eds) Xiccato G, Trocino A and Lukefahr SD, 815–819. tahara t and kanatani k (1996) Isolation, partial characterization and mode of action of acidocin J1229, a bacteriocin produced by Lactobacillus acidophilus JCM 1229. J Appl Bacteriol 81, 669–677. talon r and montel mc (1997) Hydrolysis of esters by staphylococci. Int J Food Microbiol 36, 207–214. tassou c, koutsoumanis k and nychas gje (2000) Inhibition of Salmonella enteritidis and Staphylococcus aureus in nutrient broth by mint essential oil. Food Res Int 33, 273–280. tassou cc, drosinos eh and nychas gje (1996) Effects of essential oil from mint (Mentha piperita) on Salmonella enteritidis and Listeria monocytogenes in model food systems at 4° and 10 °C. J Appl Bacteriol 78, 593–600. teuber m, perreten v and wirsching f (1996) Antibiotikum esistente Bakterien: Eine neue Dimension in der Lebensmittelmikrobiologie. Lebensmitteltechnologie 29, 182–199. thomas lv and isak t (2007) Nisin synergy with natural antioxidant extracts of the herb rosemary. ISHS Acta Horticulturae, 709. I. Int. Symp. On Natural Preservatives in Food Systems.

© Woodhead Publishing Limited, 2011

330

Processed meats

todd ecd (1983) Food-borne disease in Canada – a 5 year summary. J Food Prot 46, 650–657. tsigarida e, skandamis p and nychas gje (2000) Behaviour of Listeria monocytogenes and autochtonous flora on meat stored under aerobic, vacuum and modified atmosphere packaging conditions with or without the presence of oregano essential oil at 5 °C. J Appl Microbiol 89, 901–909. turner j (2009) A taste of the future Ajinomoto in the history of Ajinomoto, 1–12. tyopponen s, petäjä e and mattila-sandholm t (2003) Bioprotectives and probiotics for dry sausages. Int J Food Microbiol 83, 233–244. doi:10.1016/ S0168-1605(02)00379-3 vaughan ee, dally c and fitzgerald gf (1992) Identification and characterization of helveticin V-1829, a bacteriocin produced by Lactobacillus helveticus 1829. J Appl Microbiol 73, 299–308. villani f, sannino l, moschetti g, mauriello g, pepe o, amodio-cocchieri r and coppola s (1997) Partial characterization of an antagonistic substance produced by Staphylococcus xylosus 1E and determination of the effectiveness of the producer strain to inhibit Listeria monocytogenes in Italian sausages. Food Microbiol 14, 555–566. wachsman mb, farías me, takeda e, sesma f, de ruíz holgado a, de torres ra and coto ce (1999) Antiviral activity of enterocin CRL35 against herpesvirus es Int J Antimicrob Agents 12, 293–299. walsh g (2005) Therapeutic insulins and their large-scale manufacture. Appl Microbiol Biotechnol 67, 151–159. young j (2000) Functional food markets, innovations and prospects – a European analysis. Proc Health Ingredients Europe 2000. zaika ll (1988) Spices and herbs: their antibacterial activity and its determination. J Food Safety 23, 97–118.

© Woodhead Publishing Limited, 2011

13 Reducing salt in processed meat products J. M. Barat, Universidad Politécnica de Valencia, Spain and F. Toldrá, Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Spain

Abstract: Sodium intake exceeds the nutritional recommendations in most industrialised countries. The main concern for such high levels is that dietary intake of sodium, from all sources, influences blood pressure levels in significant sectors of population contributing to an increased risk of cardiovascular diseases. So, it is highly recommended by health authorities to reduce the salt content in foods and limit the consumption of salted foods and foods processed with salt (sodium). However, a global approach is necessary to reduce the salt content in meat products, considering its significant technological roles in meat processing. This chapter reviews the latest advances for sodium reduction in meat products. Key words: low salt, low sodium, low salt processed meats, meat products, dry cured ham, dry-fermented sausages.

13.1 Introduction Dietary intake of sodium, from all dietary sources, influences blood pressure levels in significant sections of the population, thereby contributing to an increased risk of coronary heart disease and both forms of stroke (WHO/ FAO, 2003). There is also a possible influence of high salt consumption on colorectal cancer (Demeyer et al., 2008), as well as evidence for less established links with other adverse health effects such as stomach cancer and osteoporosis (Gilbert and Heiser, 2005). However, sodium intake exceeds the nutritional recommendations in most industrialised countries and in most of these countries it is highly recommended by health authorities that the salt content is reduced in foods and the consumption of salted foods and foods processed with (sodium) salt is limited (WCRF, 2007). The main source of sodium in the diet is sodium chloride. There are two possible approaches for reducing the salt content in meat products. The easiest approach consists of reducing the amount of added

© Woodhead Publishing Limited, 2011

332

Processed meats

salt (Andrés et al., 2004), while the alternative consists of partially replacing the sodium salts by other salt compounds with similar technological characteristics (Sofos, 1989; Aliño et al., 2010a). Irrespective of the approach used, the role of salt in meat products must be considered in order to ensure a meat product with reduced sodium content but with accompanying an acceptable sensory and safety properties, similar to the referenced meat product containing the ‘normal’ sodium content. In recent years, some studies have indicated that the saltiness of a food product could be enhanced by reducing salt crystal size, thereby allowing for the possibility to reduce the total added salt while maintaining the desired salty taste (Angus et al., 2006; Hanley, 2005). However, if this form of salt is added to a meat product consisting of a moderate to high moisture content, this form of salt will also be dissolved and the effect of crystal size will disappear. The relevant roles of salt in meat products must be highlighted and taken into account when considering a strategy for salt reduction. Salt has strong influences on numerous sensory and safety aspects (Ruusunen and Puolanne, 2005; Desmond, 2006). Thus, a global approach is necessary to reduce the salt content in meat products, considering the relevant effects that NaCl exerts in meat products, especially on flavour, water activity, microbial stability, enzyme activity, water-holding capacity, protein solubility, texture and diffusion (Toldrá, 2006a).

13.2 Influences of salt on processed meats 13.2.1 Influence of salt on the microbial stability of processed meats Initially, one of the primary reasons for adding salt to meat was simply as a means of providing preservation (Durack et al., 2008), mainly to preserve meat from microbial spoilage (Hutton, 2002), but also for other secondary roles, like the improvement of enzyme stability in such products (Toldrá, 2002). Consequently, when reducing the sodium content in meat products, the safety aspects as well as other functional roles must be considered. Additionally and as a first technological approach, if the total water activity of the final product increases because of the reduction of the total salt, alternative preservation factors must be applied, such as using natural antimicrobials, freezing, modified atmospheres, pH manipulation (lowering pH in particular), high pressure treatments, etc. There are numerous alternative methods for ensuring meat safety when reducing the salt content like using non-thermal treatments, such as high hydrostatic pressure (Crehan et al., 2000), applying natural antimicrobial organic acids or their derived salts (Drosinos et al., 2006), using protective cultures and/or bacteriocins (Mataragas et al., 2003; Holzapfel et al., 1995; Govaris et al., 2010), using specific food grade enzymes (Holzapfel et al., 1995), adding essential oils (Skandamis et al., 2002; Gutierrez et al., 2009;

© Woodhead Publishing Limited, 2011

Reducing salt in processed meat products

333

Oussalah et al., 2006), natural plant extracts (Cui et al., 2010; Zhang et al., 2009), antimicrobial proteins (Wang, 2003), chitosan (Kanatt et al., 2008) or smoke (Holley and Patel, 2005). In a second technological approach, if the objective is to maintain the water activity in the final product, additional solutes should be added to the product in order to ensure the appropriate water activity values. In this way, the use of water activity predictive equations is of high interest (Bromley, 1973; Ross, 1975), because its use helps to determine with high precision the required amount of solutes that must be present in the final product, as a function of the moisture of the final product (Fuentes et al., 2010). If the final moisture is low, the use of sorption isotherms would be a good alternative to the use of predictive equations (Comaposada et al., 2007). There are a number of studies dealing with the influence of NaCl partial replacement on microbial loads. In 1984, Sofos published a review of the antimicrobial effects of sodium and other ions on foods. Terrell et al. (1982, 1983) did not observe significant influences of partial replacement of sodium on the microbial load of pork meat products. Experimental studies investigating NaCl partial replacement by KCl have not shown significant influences on the microbiological quality of Spanish cured ham (Blesa et al., 2008; Aliño et al., 2010a) or dry fermented sausages (Ibañez et al., 1995). The KCl capacity to increase the growth of Micrococcaceae in fermented sausages was previously observed by Ibañez et al. (1995). Growth studies for Listeria monocytogenes in broth (Boziaris et al., 2007) found that the substitution of NaCl with KCl did not decrease microbiological safety. The use of a mixture of 44% NaCl, 24% KCl and 32% CaCl2, with an ionic strength equivalent to that of the standard 100% NaCl formulation, in Spanish chorizo was not reported to affect the hygienic quality of the final product (Gimeno et al., 2001a). Some studies suggest that the growth inhibition for aerobic mesophilic bacteria is higher when using CaCl2 than that observed for either NaCl and/or KCl in pork sausages (Raccach and Henningen, 1997). No problems relating to the hygienic quality of dry fermented products have been reported when partially replacing NaCl with calcium ascorbate (Gimeno et al., 2001b). From a safety perspective, when low initial counts of pathogenic microorganisms were studied in fermented meats, KCl, K-lactate and glycine were all shown to be acceptable when used as a 40% substitution for NaCl (Gelabert et al., 2003). Antimicrobial activity has been reported for lactate ions when assessed experimentally in meat products (Houtsma et al., 1993).

13.2.2 Influence of salt on the water-holding capacity (WHC) of meat One of the main concerns of the meat industry regarding NaCl reduction in meat products is the possible decrease in the water-holding capacity (WHC) of meat products and as a consequence, the alteration of their sensory properties (e.g. tenderness) and processing yields. The influence of

© Woodhead Publishing Limited, 2011

334

Processed meats

NaCl on the WHC of meat is now well and firmly established (Offer and Knight, 1983). NaCl is traditionally used in order to increase the WHC of meat, poultry and fish products (Offer and Trinick, 1983), increasing the process yields, and in some cases, the sensory properties of the treated products. Reducing the total salt content and/or replacing NaCl by other salts could modify the WHC of the salted product. Consequently, alternative strategies should be studied in an attempt to maintain adequate WHC values in a whole range of processed muscle-based products. One possible alternative approach might be to change the pH of the product (Puolanne et al., 2001; Hultin et al., 2010), e.g. by addition of lactic acid (Medynski et al., 2000). It is well known that the minimum WHC of meat is achieved when the iso-electric point (pI) of the meat proteins is reached (Warriss, 1982), and that the WHC increases when the difference between pH and pI increases. Salts, phosphates, modified food starches, low dextrose equivalent (DE) corn syrup solids, maltodextrins, gums such as carrageenans, wheat, whey and soy protein isolates, concentrates and flours increase the yield by binding water and some fat. Another possibility exists through the addition of other salts, such as phosphates (Ruusunen et al., 2005; Wang et al., 2009). In the case of replacing NaCl with other salt, it must be taken into account that strong differences in product quality may be observed depending on the alternative salt types used (Puolanne and Halonen, 2010). Consequently, an enhancement of WHC was obtained in processed meats through the addition of lactic acid (Sawyer et al., 2008). The addition of edible seaweeds to gel/emulsion meat systems has also been reported to increase product WHC (Cofrades et al., 2008). Another possibility is the addition of 2% soy protein concentrate and at least 1% modified food starch in a chunked and formed product (Schilling et al., 2004). Ke et al. (2009) observed that the addition of citric acid increased the WHC and tenderness of beef semimembranosus muscle. Furthermore, citric acid was an effective inhibitor of lipid oxidation. The use of protein isolate made in low quality muscle foods can increase the WHC of the resulting processed products (Imer, 2007). Physical treatments can be used to enhance the WHC of meat products when salt content is reduced. It has been demonstrated that high pressure technology is a viable process that partially compensates for the reduction of salt in frankfurters (Crehan et al., 2000) and in beef sausage batters (Sikes et al., 2009).

13.2.3 Influence of salt on protein solubility and texture Salt plays an important role in meat texture, because of its role in the solubilisation of myofibrillar meat proteins, actin and myosin (Xiong, 1997), and its influence on the WHC of the proteins. When salt is added and proteins are solubilised, viscosity of meat batters increase (Desmond, 2006). The reduction in salt concentration implies a decrease in extracted and

© Woodhead Publishing Limited, 2011

Reducing salt in processed meat products

335

solubilised myofibrilars proteins, affecting the functionality of the meat system. Barbut and Mittal (1989) studied the effect of salt reduction on the rheological and gelation properties of beef, pork and poultry meat batters. They observed a decrease in shear stress with decreasing salt levels. Texture could be improved by using high pressure in poultry meat batters (Carballo et al., 2001) or dry-cured ham (Campus et al., 2008). The replacement of NaCl with other salts such as calcium, magnesium or potassium chloride in meat batters enhanced protein extraction and solubility, emulsion stability, and favoured the orderly gelation of proteins (Nayak et al., 1998a, 1998b; Piggot et al., 2000). In any case, a detailed study of the reduction of salt and/or its partial replacement by other compounds must be carried out in order to determine its influence on final product texture and alternatives to improve texture may be required (Totosaus and Pérez-Chabela, 2009). For instance, a low salt content can lead to softening textural problems in Spanish dry cured hams (Morales et al., 2007) owing to the higher activity of muscle cathepsins that contribute to an extended protein breakdown, resulting in an unacceptable softening of the final product (Toldrá, 2006b, 2007).

13.3

Development of processed meats with low salt content

There are numerous reports for salt reduction in muscle food products in the literature and Table 13.1 summarises some examples of published work which addressed sodium reduction in food products. Some of the most fundamental studies have focused on determining the influence of new ingredient mixtures, with partial NaCl replacement, on the salting kinetics of pork meat (Aliño et al., 2009a; Costa-Corredor et al., 2010). Such studies are important from the context of trying to understand how the salting and post-salting stages for pig meat products are required to be adapted to the salt mixture used (Aliño et al., 2010b). A strong influence of the ion type on the salting kinetics was recently reported (Aliño et al., 2009a). These authors showed that potassium ions accelerated the salting process while the divalent cations Ca2+ and Mg2+ decreased the salting kinetics. Furthermore, lactate was reported to cause no interference on the diffusivity of the chloride ion, and that the diffusion coefficient of lactate was significantly lower than that of Na+ (Costa-Corredor et al., 2010). Other studies have focused in determining the sorption isotherms of minced pork salted with KCl as a substitute for NaCl (Comaposada et al., 2007). The authors of the study observed that the water content at equilibrium was higher in minced meat with NaCl than in minced meat with KCl, but the isotherms were similar when the substitution was around 30%. The desorption isotherms of salted minced pork using K-lactate as a substitute for NaCl were also assayed (Muñoz et al., 2009), observing a

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Product

Small fermented sausages

Meat patties

Sausages

Emulsionbased products

Frankfurters

Reference

Guàrdia et al. (2008)

Ruusunen et al. (2005)

Ruusunen et al. (2003)

Cofrades et al. (2008)

López-López et al. (2009)

Addition of seaweeds

Reduction of the total amount of NaCl (formulation variables: sodium, fat and phosphate content) Mixture of carboxymethyl cellulose, carrageenan and sodium citrate The addition of seaweeds to improve the water and fat binging properties of salt

50% substitution of NaCl by mixtures of KCl and potassium lactate

Followed strategy

Improvement the formation of harder and chewier structures with good water and fat-binding properties at low salt content in meat patties, providing not only dietary fibre but also other bioactive components such as antioxidant polyphenols or carotenoids. Adding seaweed had little effect on the lipid and amino acid profiles of frankfurters. It constitutes a means to produce low-sodium products with important dietary fibre content, with better Na/K ratios and rich in Ca.

Decreased frying loss, increased saltiness, increased flavour intensity, increased firmness and juiciness of low salt sausage.

Consumers rejected fermented sausages with high K-lactate but not those with a high KCl. It is possible to achieve a reduction of 50% of NaCl in small calibre fermented sausages and to obtain a product acceptable to most consumers. The increase in fat content increased the perceived saltiness. The use of phosphate decreased the cooling loss and improved the firmness.

Main conclusions

Table 13.1 Some recent data for the reduction of the sodium content in certain meat products, with indication of the followed strategy and the main outcomes

© Woodhead Publishing Limited, 2011

Fermented sausages

Frankfurters

Dry-cured hams

Italian salami

Gimeno et al. (2001b)

Crehan et al. (2000)

Fulladosa et al. (2009)

Zanardi et al. (2010) Ibáñez et al. (1996)

Dry fermented sausages

Fermented sausages

Gelabert et al. (2003)

Partial replacement of NaCl by KCl, MagCl2 and CaCl2 Partial replacement of NaCl with KCl

Addition of potassium lactate combined with high pressure

Using high hydrostatic pressure

Using calcium ascorbate as substitute

Substitution of NaCl by KCl, potassium lactate (K-lactate) or glycine.

The partial substitution (above 40%) of NaCl with different mixtures of KCl/glycine and K-lactate/glycine showed important flavour and textural defects which did not permit an increase in the level of substitution compared with those obtained with the individual components. Partial substitution of NaCl by calcium ascorbate caused higher acidification. Significant higher a* and b* values and lower L* values, and lower hardness and gumminess values in relation to the control. No problems related to the hygienic quality were observed. It has been demonstrated that high pressure technology is a viable process that partially compensates for the reduction of salt levels in frankfurters. The boning–salting–binding methodology, combined with the addition of potassium lactate as NaCl substitute, enabled the production of restructured dry-cured hams with 15 g/kg of added NaCl. The addition of K-lactate did not have a negative effect on colour, flavour or texture of dry-cured hams. However, the high pressure treatment (600 MPa) of the final product had a significant effect on the flavour and the texture attributes as well as on the overall slice appearance. A 40% lowering of Na content with limited detrimental effects on sensory attribute was allowed. The reduction in salt concentration did not affect the Micrococcaceae count. A positive effect on the intensity of lipolytic activity was observed as a consequence of the decreased salt level. There was no decrease in the oxidative processes.

338

Processed meats

similar behaviour in the range of water activity from 0.7 to 1, while below 0.7, water equilibrium content fell faster for meat with NaCl than for meat with K-lactate. These studies are important in terms of understanding the drying processes required for the development of certain salted processed meat products. Some attempts have been carried out in order to develop dry-cured pork loin using salt reduction by employing K-lactate and glycine (Gou et al., 1996) or a mixture of KCl, MgCl2 and CaCl2 (Aliño et al., 2009b, 2010c; Armenteros et al., 2009a, 2009b,c). These studies concluded that NaCl content could be reduced by as much as 40–50%, without significantly effecting sensory and/or safety characteristics of the final product.

13.3.1 Influence of sodium reduction on the processing of dry-cured ham Developing a low sodium product always implies that the processing method must be adapted to the new product being developed. In the case of reducing the total salt content, the salting step is usually very easy to modify, just by reducing the concentration or amount of injected brine, reducing the amount of added salt in formulated products, or reducing the salting time. Nevertheless, some of the processing steps should be modified in order to ensure the safety of the product; e.g. use of high pressure or through the addition of certain preservatives. When using a mixture of salts for partial replacement of sodium, the salting stage must be modified in order to adapt it to the new process. Thus, some aspects that must be considered are: • usually the salt mixtures are more expensive than common salt, so the minimisation of the lost salt becomes more important; • the solubility of the used salt mixtures can change; for example, the ion concentration in the formed brine or pile salting of hams can differ to a large extent, based on the ratio used for formulating the salt mixture (i.e. 70% NaCl : 30% KCl); • salt rate uptake can differ from one salt to another because of differences in charge density, size, brine pH, etc.; and • salt diffusion inside the salted product can change because of salt transformation, making it necessary to adapt salting time and/or post-salting stages to meet the challenges presented through the use of the new salt type. Recent research studies for NaCl reduction in Spanish dry-cured hams have also been reported. The initial approaches consisted of reducing the total added salt and thus, some studies evaluated the possibility of reducing the total added salt and consequently, study its effects on the sensory characteristics and proteolysis of Iberian hams (Andrés et al., 2004; Martín et al., 1998) and on physicochemical and sensory parameters of restructured dry-cured hams (Costa-Corredor et al., 2009). Other authors have assayed

© Woodhead Publishing Limited, 2011

Reducing salt in processed meat products

339

the partial replacement of NaCl with either K-lactacte (Costa-Corredor et al., 2009; Fulladosa et al., 2009), or a mixture of KCl alone or mixed with MgCl2 and CaCl2 (Aliño et al., 2010a; Ripollés et al., 2011). Similar to the results obtained with dry-cured pork loin, an approximate 40% Na+ reduction could be achieved without negatively affecting sensory properties. Larger reductions can affect some properties, especially taste, where some bitter and metallic aftertastes may be perceived.

13.3.2 Effect of salt replacers on the muscle enzyme activity It has been reported in the literature that NaCl exerts an important role in controlling muscle enzyme activity, especially porcine muscle proteases such as cathepsins, dipeptidylpeptidases and aminopeptidases (Toldrá and Flores, 1998). This effect is important in proteolysis phenomena that happen quite extensively during the processing of dry-cured hams (Toldrá, 2006c). The effect of different chloride salts (NaCl, KCl, MgCl2 and CaCl2) on muscle peptidases has been studied (Armenteros et al., 2009c). In general, the effect exerted by divalent salts (CaCl2 and MgCl2) was quite more pronounced. A significant effect was observed for arginyl aminopeptidase, that was activated by NaCl and KCl and low amounts of MgCl2, while CaCl2, and demonstrated a strong inhibitory effect which was above 80% (Armenteros et al., 2009c).

13.3.3

Effect of salt replacers on the perception of aroma volatile compounds The aroma perception in meat products depends on the concentration and odour threshold of volatile compounds and on their interactions with other food components, which will affect their gas phase concentration (Guichard, 2002). This is of particular interest in the case of dry-cured ham where there is a wide variety of aroma volatile compounds (Toldrá and Aristoy, 2010). The effect of using different salts (NaCl, KCl, MgCl2 and CaCl2) on the volatile compound headspace concentration in water solutions was recently reported (Pérez-Juan et al., 2007). KCl produced a similar saltingout effect as NaCl, increasing the volatile compound headspace concentration by 5–10 fold, while MgCl2 and CaCl2 did not produce a similar salting-out effect. The impact of these salts on the binding ability of porcine soluble protein extracts was also studied using key volatile compounds. NaCl and KCl produced a significant reduction on the binding ability of sarcoplasmic protein extracts to branched aldehydes, hexanal and methional, while no effect was produced on octanal and 2-pentanone. The effects of MgCl2 and CaCl2 were much lower, even at high ionic strengths, with the exception of the branched aldehydes, where the presence of MgCl2 at 1.0 ionic strength produced the complete liberation of bound volatile compounds. From these

© Woodhead Publishing Limited, 2011

340

Processed meats

results, it is evident that partial replacement of NaCl by other salts in meat products must be considered, not only because of their salting-out effect, but also because of their effect on protein binding ability (Pérez-Juan et al., 2006).

13.3.4 Use of masking agents One of the major problems when replacing sodium chloride by other salts, especially potassium chloride, is the appearance of bitter tastes or even metallic aftertaste. The use of masking agents constitute attractive strategies to avoid or reduce the developed bitterness or undesirable off-flavours (Lahtinen, 1986; Toldrá and Barat, 2009), or the use of flavour enhancers that enhance the saltiness of meat products, such as glycine or a combination of carboxymethyl cellulose and carrageenan in combination with sodium citrate (Ruusunen et al., 2003). Currently, masking agents are being commercialised for low-sodium applications in foods (http://www.lifewiseingredients.com/).

13.4 Sources of further information and advice WCRF, 2007 World Cancer Research Fund/American Institute for Cancer Research (2007). Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective (517 pp.). Washington, DC: American Institute for Cancer Research. WHO/FAO (World Health Organization/Food and Agriculture Organisation) (2003) Diet, Nutrition and the Prevention of Chronic Diseases. WHO Technical Report Series 916. Geneva, World Health Organization.

13.5 References aliño, m.; grau, r.; baigts, d.; barat, j.m. (2009a) Influence of sodium replacement on the salting kinetics of pork loin. Journal of Food Engineering, 95, 551–557. aliño, m.; grau, r.; toldrá, f.; blesa, e.; pagán, m.j., barat, j.m. (2009b) Influence of sodium replacement on physicochemical properties of dry-cured loin. Meat Science, 83, 423–430. aliño, m.; grau, r.; toldrá, f.; barat, j.m. (2010a) Physicochemical changes in drycured hams salted with potassium, calcium and magnesium chloride as a partial replacement for sodium chloride. Meat Science, 86, 331–336. aliño, m.; grau, r.; fuentes, a.; barat, j.m. (2010b) Influence of low-sodium mixtures of salts on the post-salting stage of dry-cured ham process. Journal of Food Engineering, 99, 198–205. aliño, m.; grau, r.; toldrá, f.; blesa, e.; pagán, m.j.; barat, j.m. (2010c) Physicochemical properties and microbiology of dry-cured loins obtained by partial sodium replacement with potassium, calcium and magnesium. Meat Science, 85, 580–588.

© Woodhead Publishing Limited, 2011

Reducing salt in processed meat products

341

andrés, a.i.; cava, r.; ventanas, j.; thovar, v.; ruiz, j. (2004) Sensory characteristics of Iberian ham: Influence of salt content and processing conditions. Meat Science, 68, 45–51. angus, f.; phelps, t.; clegg, s.; narain, c.; den ridder, c.; kilcast, d. (2006) Salt in Processed Foods: Collaborative Research Project. Leatherhead Food International. armenteros, m.; aristoy, m.c.; barat, j.m.; toldrá, f. (2009a) Biochemical changes in dry-cured loins salted with partial replacements of NaCl by KCl. Food Chemistry, 117, 627–633. armenteros, m.; aristoy, m.c.; barat, j.m.; toldrá, f. (2009b) Biochemical and sensory properties of dry-cured loins as affected by partial replacement of sodium by potassium, calcium and magnesium. Journal of Agricultural & Food Chemistry, 57, 9699–9705. armenteros, m.; aristoy, m.c.; toldrá, f. (2009c) Effect of sodium, potassium, calcium and magnesium chloride salts on pork muscle proteases. European Food Research and Technology, 229, 93–98. barbut, s.; mittal, g.s. (1989) Effects of salt reduction on the rheological and gelation properties of beef, pork and poultry meat batters. Meat Science, 26(3), 177–191. blesa, e.; aliño, m.; barat, j.m.; grau, r.; toldrá, f.; pagán, m.j. (2008) Microbiology and physico-chemical changes of dry-cured ham during the post-salting stage as affected by partial replacement of NaCl by other salts. Meat Science, 78, 135–142. boziaris, s.; skandamis, p.n.; anastasiadi, m.; nychas, g.j.e. (2007) Effect of NaCl and KCl on fate and growth/no growth interfaces of Listeria monocytogenes Scott A at different pH and nisin concentrations. Journal of Applied Microbiology, 102, 796–805. bromley, l.a. (1973). Thermodynamic properties of strong electrolytes in aqueous solutions. American Chemistry Society, 60, 309–320. campus, m.; flores, m.; martinez, a.; toldrá, f. (2008) Effect of high pressure treatment on colour, microbial and chemical characteristics of dry cured loin. Meat Science, 80, 1174–1181. carballo, j.; cofrades, s.; fernández-martín, f.; jiménez-colmenero, f. (2001) Pressure-assisted gelation of chemically modified poultry meat batters. Food Chemistry, 75, 203–209. cofrades, s.; lópez-lópez, i.; solas, m.t.; bravo, l.; jiménez-colmenero, f. (2008) Influence of different types and proportions of added edible seaweeds on characteristics of low-salt gel/emulsion meat systems. Meat Science, 79, 767–776. comaposada, j.; arnau, j.; gou, p. (2007) Sorption isotherms of salted minced pork and of lean surface of dry-cured hams at the end of the resting period using KCl as substitute for NaCl. Meat Science, 77, 643–648. costa-corredor, a.; serra, x.; arnau, j.; gou, p. (2009) Reduction of NaCl content in restructured dry-cured hams: post-resting temperature and drying level effects on physicochemical and sensory parameters. Meat Science, 83, 390–397. costa-corredor, a.; muñoz, i.; arnau, j.; gou, p. (2010) Ion uptakes and diffusivities in pork meat brine-salted with NaCl and K-lactate. LWT – Food Science and Technology, 43, 1226–1233. crehan, m.; troy, d.j.; buckley, d.j. (2000) Effects of salt level and high hydrostatic pressure processing on frankfurters formulated with 1.5 and 2.5% salt. Meat Science, 55(1), 123–130. cui, h.; gabriel, a.a.; nakano, h. (2010) Antimicrobial efficacies of plant extracts and sodium nitrite against Clostridium botulinum. Food Control, 21, 1030–1036. demeyer, d.; honikel, k.; de smet, s. (2008) The World Cancer Research Fund report 2007: A challenge for the meat processing industry. Meat Science, 80, 953–959.

© Woodhead Publishing Limited, 2011

342

Processed meats

desmond, e. (2006) Reducing salt: a challenge for the meat industry. Meat Science, 74, 188–196. drosinos, e.h.; mataragas, m.; kampani, a.; kritikos, d.; metaxopoulos, i. (2006) Inhibitory effect of organic acid salts on spoilage flora in culture medium and cured cooked meat products under commercial manufacturing conditions. Meat Science, 73(1), 75–81. durack, e.; alonso-gomez, m.; wilkinson, m.g. (2008) Salt: a review of its role in food science and public health. Current Nutrition & Food Science, 4, 290–297. fuentes, a.; fernández-segovia, i.; serra, j.a.; barat, j.m. (2010) Development of smoked sea bass with partial sodium replacement. LWT – Food Science and Technology, 43, 1426–1433. fulladosa, e.; serra, x.; gou, p.; arnau, j. (2009) Effects of potassium lactate and high pressure on transglutaminase restructured dry-cured hams with reduced salt content. Meat Science, 82, 213–218. gelabert, j.; gou, p.; guerrero, l.; arnau, j. (2003) Effect of sodium chloride replacement on some characteristics of fermented sausages. Meat Science, 65, 833–839. gilbert, p.a. and heiser, g. (2005) Salt and health: the CASH and BPR perspective. British Foundation Nutrition Bulletin, 30, 62–69. gimeno, o.; astiasarán, i.; bello, j. (2001a) Influence of partial replacement of NaCl with KCl and CaCl2 on microbiological evolution of dry fermented sausages. Food Microbiology, 18, 329–334. gimeno, o.; astiasarán, i.; bello, j. (2001b) Calcium ascorbate as a potential partial substitute for NaCl in dry fermented sausages: effect on colour, texture and hygienic quality at different concentrations. Meat Science, 57, 23–29. gou, p.; guerrero, l.; gelabert, j.; arnau, j. (1996) Potassium chloride, potassium lactate and glycine as sodium chloride substitutes in fermented sausages and in dry-cured pork loin. Meat Science, 42, 37–48. govaris, a.; solomakos, n.; pexara, a.; chatzopoulou, p.s. (2010) The antimicrobial effect of oregano essential oil, nisin and their combination against Salmonella Enteritidis in minced sheep meat during refrigerated storage. International Journal of Food Microbiology, 137, 175–180. guàrdia, m.d.; guerrero, l.; gelabert, j.; gou, p.; arnau, j. (2008) Sensory characterisation and consumer acceptability of small calibre fermented sausages with 50% substitution of NaCl by mixtures of KCl and potassium lactate. Meat Science, 80, 1225–1230. guichard, e. (2002). Interactions between flavor compounds and food ingredients and their influence on flavor perception. Food Reviews International, 18, 49–70. gutierrez, j.; barry-ryan, c.; bourke, p. (2009) Antimicrobial activity of plant essential oils using food model media: efficacy, synergistic potential and interactions with food components. Food Microbiology, 26, 142–150. hanley, b. (2005) Salt, sugar and fat reduction in foods – technological challenges. Presentation given at Fat, Sugar and Salt: A question of balance event, Dublin. April 2005. Leatherhead Food International. holley, r.; patel, d. (2005) Improvement in shelf-life and safety of perishable foods by plant Essentials oils and smoke antimicrobials. Food Microbiology, 22, 273–292. holzapfel, w.h.; geisen, r.; schillinger, u. (1995) Biological preservation of foods with reference to protective cultures, bacteriocins and food grade enzymes. International Journal of Food Microbiology, 24, 343–362. houtsma, p.c.; de wit, j.c.; rombouts, f.m. (1993) Minimum inhibitory concentration (MIC) of sodium lactate for pathogens and spoilage organisms occurring in meat products. International Journal of Food Microbiology, 20, 247–257.

© Woodhead Publishing Limited, 2011

Reducing salt in processed meat products

343

hultin, h.o.; ke, s.; huang, y.; imer, s.; vareltzis, p. (2010) Process for improving water holding capacity and tenderness in cooked protein food products. USPTO Applicaton 20100009048 – Class: 426281 (USPTO). hutton, t. (2002) Sodium: technological functions of salt in the manufacturing of food and drink products. British Food Journal, 104, 126–152. ibáñez, c.; quintanilla, l.; irigoyen, a.; garcía-jalón, i.; cid, c.; astiasarán, i.; bello, j. (1995) Partial replacement of sodium chloride with potassium chloride in dry fermented sausages: influence on carbohydrate fermentation and nitrosation process. Meat Science, 40, 45–53. ibáñez, c.; Quintanilla, l.; cid, c.; astiasaran, i.; bello, j. (1996) Dry fermented sausages elaborated with Lactobacillus plantarum–Staphylococcus carnosus Part I: Effect of partial replacement of NaCl with KCl on the stability and the nitrosation process. Meat Science, 44(4), 227–234. imer, s. (2007) Increasing water holding capacity of muscle foods: Protein isolate effect. Electronic Doctoral Dissertations for UMass Amherst. Paper AAI3254954. http://scholarworks.umass.edu/dissertations/AAI3254954. kanatt, s.r.; chander, r.; sharma, a. (2008) Chitosan and mint mixture: a new preservative for meat and meat products. Food Chemistry, 107(2), 845–852. ke, s.; huang, y.; decker, e.a.; hultin, h.o. (2009) Impact of citric acid on the tenderness, microstructure and oxidative stability of beef muscle. Meat Science, 82(1), 113–118. lahtinen, s. (1986) Masking the bitter taste of salt substitutes with lactose in combination with sucrose, or glucose and galactose in food emulsions. Journal of Food Quality, 9(4), 199–204. lópez-lópez, i.; cofrades, s.; ruiz-capillas, c.; jiménez-colmenero, f. (2009) Design and nutritional properties of potential functional frankfurters based on lipid formulation, added seaweed and low salt content. Meat Science, 83, 255–262. martín, l.; córdoba, j.j.; antequera, t.; timón, m.l.; ventanas, j. (1998) Effects of salt and temperature on proteolysis during ripening of Iberian ham. Meat Science, 49(2), 145–153. mataragas, m.; drosinos, e.h.; metaxopoulos, j. (2003) Antagonistic activity of lactic acid bacteria against Listeria monocytogenes in sliced cooked cured pork shoulder stored under vacuum or modified atmosphere at 4 ± 2 °C. Food Microbiology, 20, 259–265. medynski, a.; pospiech, e.; kniat, r. (2000) Effect of various concentrations of lactic acid and sodium chloride on selected physico-chemical meat traits. Meat Science, 55(3), 285–290. morales, r.; serra, x.; guerrero, l.; gou, p. (2007) Softness in dry-cured porcine biceps femoris muscles in relation to meat quality characteristics and processing conditions. Meat Science, 77, 662–669. muñoz, i.; arnau, j.; costa-corredor, a.; gou, p. (2009) Desorption isotherms of salted minced pork using K-lactate as a substitute for NaCl. Meat Science, 83, 642–646. nayak, r.; kenney, p.b.; slider, s.; head, m.k.; killefer, j. (1998a) Cook yield, texture and gel ultrastructure of model beef batters as affected by low levels of calcium, magnesium and zinc chloride. Journal of Food Science, 63, 945–950. nayak, r.; kenney, p.b.; slider, s.; head, m.k.; killefer, j. (1998b). Myofibrillar protein solubility affected by low levels of calcium, magnesium and zinc chloride. Journal of Food Science, 63, 951–954. offer, g.; knight, p. (1983) The structural basis of water-holding in meat. Part 1: General principles and water uptake in meat processing. In R. A. Lawrie, Developments in Meat Science. London: Elsevier Applied Science. offer, g.; trinick, j. (1983) On the mechanism of water holding in meat: the swelling and shrinking of myofibrils. Meat Science, 8, 245–281.

© Woodhead Publishing Limited, 2011

344

Processed meats

oussalah, m.; caillet, s.; saucier, l.; lacroix, m. (2006) Antimicrobial effects of selected plant essential oils on the growth of a Pseudomonas putrida strain isolated from meat. Meat Science, 73, 236–244. pérez-juan, m.; flores, m.; toldrá, f. (2006). Model studies on the efficacy of protein homogenates from raw pork muscle and dry-cured ham in binding selected flavor compounds. Journal of Agricultural and Food Chemistry, 54, 4802–4808. pérez-juan, m.; flores, m.; toldrá, f. (2007) Effect of ionic strength of different salts on the binding of volatile compounds to sarcoplasmic protein homogenates in model systems. Food Research International, 40, 687–693. piggot, r.s.; kenney, p.b.; slider, s.; head, m.k. (2000) Formulation protocol and dicationic salts affect protein functionality on model systems beef batters. Journal of Food Science, 65, 1151–1154. puolanne, e.; halonen, m. (2010) Theoretical aspects of water-holding in meat. Meat Science, 86, 151–165. puolanne, e.j.; ruusunen, m.h.; vainionpää, j.i. (2001) Combined effects of NaCl and raw meat pH on water-holding in cooked sausage with and without added phosphate. Meat Science, 58, 1–7. raccach, m.; henningen, e.c. (1997) The effect of chloride salts on Yersinia enterocolitica in meat. Food Microbiology, 14, 431–438. ripollés, s.; campagnol, p.c.b.; armenteros, m.; aristoy, m.c.; toldrá, f. (2011) Influence of partial replacement of NaCl for KCl, CaCl2 and MgCl2 in lipolysis and lipid oxidation on dry-cured ham. Meat Science, 89, 58–64. ross, k.d. (1975) Estimation of water activity in intermediate moisture foods. Food Technology, 29, 26–34. ruusunen, m.; puolanne, e. (2005) Reducing sodium intake from meat products. Meat Science, 70, 531–541. ruusunen, m.; vainionpää, j.; puolanne, e.; lyly, m.; lahteenmaki, l.; niemisto, m. (2003) Effect of sodium citrate, carboxymethyl cellulose and carrageenan levels on quality characteristics of low-salt and low-fat bologna type sausages. Meat Science, 64, 371–381. ruusunen, m.; vainionpää, j.; lyly, m.; lähteenmäki, l.; niemistö, m.; ahvenainen, r.; puolanne, e. (2005) Reducing the sodium content in meat products: the effect of the formulation in low-sodium ground meat patties. Meat Science, 69(1), 53–60. sawyer, j.t.; apple, j.k.; johnson, z.b. (2008) The impact of lactic acid concentration and sodium chloride on pH, water-holding capacity, and cooked color of injectionenhanced dark-cutting beef. Meat Science, 79, 317–325. schilling, m.w.; marriott, n.g.; acton, j.c.; anderson-cook, c.; alvarado, c.z.; wang, h. (2004) Utilization of response surface modeling to evaluate the effects of nonmeat adjuncts and combinations of PSE and RFN pork on water holding capacity and cooked color in the production of boneless cured pork. Meat Science, 66, 371–381. sikes, a.l.; tobin, a.b.; tume, r.k. (2009) Use of high pressure to reduce cook loss and improve texture of low-salt beef sausage batters. Innovative Food Science & Emerging Technologies, 10, 405–412. skandamis, p.; tsigarida, e.; nychas, g.j.e. (2002) The effect of oregano essential oil on survival/death of Salmonella typhimurium in meat stored at 5 °C under aerobic VP/MAP conditions. Food Microbiology, 19, 97–103. sofos, j.n. (1984) Antimicrobial effects of sodium and other ions in foods: a review. Journal of Food Safety, 6, 45–78. sofos, j.n. (1989) Phosphates in meat products. In S. Thorne (Ed.), Developments in Food Preservation – 5. New York: Elsevier Applied Science. 207–252. terrell, r.n.; childers, a.b.; kayfus, t.j.; ming, c.g.; smith, g.c.; kotula, a.w.; johnson, h.k. (1982) Effect of chloride salts and nitrite on survival of trichina larvae and other properties of pork sausages. Journal of Food Protection, 45, 281–284.

© Woodhead Publishing Limited, 2011

Reducing salt in processed meat products

345

terrell, r.n.; quintanilla, m.; vanderzant, c.; gardner, f.a. (1983) Effects of reduction or replacement of sodium chloride on growth of Micrococcus, Moraxella and Lactobacillus inoculated ground pork. Journal Food Science, 48, 122–124. toldrá, f. (2002) Dry-cured Meat Products. Ames, IA; Wiley-Blackwell. toldrá, f. (2006a) Dry-cured ham. In: Y.H. Hui, E. Castell-Perez, L.M. Cunha, I. Guerrero-Legarreta, H.H. Liang, Y.M. Lo, D.L. Marshall, W.K. Nip, F. Shahidi, F. Sherkat, R.J. Winger, K.L. Yam (Eds.), Handbook of Food Science, Technology and Engineering volume 4. Boca Raton, FL: CRC Press, 164-1–164-11. toldrá, f. (2006b) Meat: chemistry and biochemistry. In: Y.H. Hui, J.D. Culbertson, S. Duncan, I. Guerrero-Legarreta, E.C.Y. Li-Chan, C.Y. Ma, C.H. Manley, T.A. McMeekin, W.K. Nip, L.M.L. Nollet, M.S. Rahman, F. Toldrá, Y.L. Xiong (Eds.), Handbook of Food Science, Technology and Engineering volume 1. Boca Raton, FL: CRC Press, 28-1–28-18. toldrá, f. (2006c) Biochemical proteolysis basis for improved processing of drycured meats. In: L.M.L. Nollet and F. Toldrá (Eds.), Advanced Technologies for Meat Processing. Boca Raton, FL: CRC Press, 329–351. toldrá, f. (2007) Biochemistry of muscle and fat. In: F. Toldrá, Y.H. Hui, I. Astiasarán, W.K. Nip, J.G. Sebranek, E.T.F. Silveira, L.H. Stahnke & R. Talon (Eds.), Handbook of Fermented Meat and Poultry. Ames, IA: Blackwell Publishing, 51–58. toldrá, f. & aristoy, m.c. (2010) Dry-cured ham. In: F. Toldrá (Ed.), Handbook of Meat Processing. Ames, IA: Wiley-Blackwell, 351–362. toldrá, f.; barat, j.m. (2009) Recent patents for sodium reduction in foods. Recent Patents on Food, Nutrition & Agriculture, 1, 80–86. toldrá, f.; flores, m. (1998) ‘The role of muscle proteases and lipases in flavor development during the processing of dry-cured ham’ CRC Critical Reviews in Food Science and Nutrition 38, 331–352. totosaus, a.; pérez-chabela, m.l. (2009) Textural properties and microstructure of low-fat and sodium-reduced meatbatters formulated with gellan gum and dicationic salts. LWT – Food Science and Technology, 42, 563–569. wang, f.s. (2003) Effect of antimicrobial proteins from porcine leukocytes on Staphylococcus aureus and Escherichia coli in comminuted meats. Meat Science, 65(1), 615–621. wang, p.; xu, x-l.; zhou, g.h. (2009) Effects of meat and phosphate level on waterholding capacity and texture of emulsion-type sausage during storage. Agricultural Sciences in China, 8, 1475–1481. warriss, p.d. (1982) The relationship between pH and drip in pig muscle. Journal of Food Technology, 17, 573–578. wcrf, 2007 world cancer research fund/american institute for cancer research (2007) Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective (517 pp.). Washington, DC: American Institute for Cancer Research. who/fao (world health organization/food and agriculture organisation) (2003) Diet, nutrition and the prevention of chronic diseases. WHO Technical Report Series 916. Geneva, World Health Organization. xiong, y.l. (1997) Structure/function relationship of muscle proteins. In: S. Damodaran and A. Paraf (Eds.), Food Proteins and their Applications. New York: Marcel Dekker. zanardi, e.; ghidini, s.; conter, m.; ianieri, a. (2010) Mineral composition of Italian salami and effect of NaCl partial replacement on compositional, physico-chemical and sensory parameters. Meat Science, 86, 742–747. zhang, h.; kong, b.; xiong, y.l.; sun, x. (2009) Antimicrobial activities of spice extracts against pathogenic and spoilage bacteria in modified atmosphere packaged fresh pork and vacuum packaged ham slices stored at 4 °C. Meat Science, 81, 686–692.

© Woodhead Publishing Limited, 2011

14 Reducing fats in processed meat products S. Barbut, University of Guelph, Canada

Abstract: Fat reduction in meat products represents special challenges, as animal fat contributes to texture, mouth feel, flavor, juiciness as well as energy. Fat reduction by itself usually results in dry and less acceptable products. This chapter reviews various approaches studied over the last half a century, and focuses on ground meat patties, coarse sausages, finely comminuted sausages, and whole muscle products. Some of the successful products on the market today utilize a combination of several approaches such as lowering the overall animal fat level, substituting part of it with more unsaturated vegetable oils, replacing another part with water mixed with hydrocolloid gums/starches/fiber as well as adding other non-meat proteins to mimic some of the fat sensation. Key words: meat, beef, pork, chicken, sausage, animal fat, vegetable oil, fiber, protein, texture, flavor, gum.

14.1 Introduction: importance of reducing fat in processed meat products Fats and oils play important functional, sensory and nutritional roles in various food products. Fats interact with other ingredients to develop texture and mouthfeel and assist in the overall sensation of lubricity in foods (Giese, 1996). Fat present/added into meat products also plays an important role in rheological and structural properties as well as providing a unique taste profile (Rakosky, 1970; Hughes et al., 1998; Jiménez-Colmenero, 2007; Cáceres et al., 2008). Animal fats are relatively high in saturated fatty acids compared to vegetable oils such as canola and olive oil, and animal fats contain cholesterol; both factors have been implicated in increasing plasma low density lipoprotein (Grundy and Denke, 1990). The proposed relationships between cholesterol level and low polyunsaturated/saturated fatty acids (PUFA/SFA) ratio and the rise in coronary heart diseases has resulted in focusing on high fat food products including several meat products (Giese,

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

347

1992; Dransfield, 2008). Various studies have been published on strategies to reduce animal fat usage in meat products. Such attempts have included replacing some of the fat with water, replacing fat with mixtures of water/ starch or hydrocolloid gums, substituting animal fat with vegetable oils as well as trying some synthetic fat substitutes; all giving rise to products with an improved fatty acid profile and lower cholesterol than traditional ones (Keeton, 1994; Teye et al., 2006; Özvural and Vural, 2008). Studies on fat reduction in meat products started to appear in the scientific literature in the 1970s but intensified in the early 1990s and are obviously a hot topic in the new millennium. Early work on reducing fat content in ground meat products (e.g., from 25 to 10% and below) often resulted in cooked hamburger patties that were bland and dry with a hard, rubbery or mealy texture (Berry and Leddy, 1984; USDA, 1986). However, reformulation with certain fat substitutes improved particle binding and lack of beef flavor and reduced browning reactions and shorter microbiological shelflife to a certain extent (Keeton, 1994). Sausages (e.g., salami, bologna) produced with low fat (≤10%) showed reduced cook yields, soft mushy interiors, rubbery skin formation, excessive purge in vacuum packages, shorter shelf-life and changes in sensory qualities after cooking or reheating. Later work has been focusing on finding fat replacers that could mimic the mouthfeel and textural characteristics of fat, for the development of low fat meat products. An ideal fat substitute should be an ingredient that contributes no/low calories and does not dramatically alter mouthfeel, flavor, juiciness, or other organoleptic and processing properties. Most substitutes are used for partial replacement of the fat and can be categorized as: (a) leaner meats (fatreduced, partially defatted); (b) added water; (c) protein-based substitutes (e.g., blood plasma, egg proteins, milk caseinates, non-fat dry milk, soy proteins in the form of flour/concentrates/isolates, wheat proteins, whey proteins); (d) carbohydrate-based substitutes (e.g., fiber, cellulose, starches, maltodextrins, dextrins, hydrocolloid gums); (e) synthetic compounds (e.g., Polydextrose®, Olestra® or sucrose polyester) (Keeton, 1994). As will be discussed in this chapter, the most common approach today is to employ a combination of two or three of the options mentioned above. Overall, the meat industry has gained a lot of knowledge about the use of fat replacements over the past 15 years; however, more insight and better understanding are needed to elucidate the interactions among sausage ingredients, processing conditions, consumer demands, and final product’s preparation methods.

14.2 Role of fat in processed meat products The content and type of fat in fresh meat, in relation to eating quality as they impact on meat production, have been studied systematically for over three decades. Studies have mainly focused on variations in ‘neutral lipids’

© Woodhead Publishing Limited, 2011

348

Processed meats

as opposed to the phospholipids, which are present mainly in membranes. In fresh meat cuts, the fat content, from most species, is important in appearance and some research approaches linked intuitively the fat content with its role in texture, comprising tenderness and juiciness, and in flavor (Dransfield, 2008). In general, the consumer evaluation of fat in fresh meat cuts comprises elements of the fat itself (its amount and quality), as well as the consumer’s sensory capacities and cultural background. In both fresh and processed meat products the characteristic meat flavor is produced during cooking by a complex series of reactions that occur between non-volatile components of lean and fatty tissues (see review by Mottram, 1998). Currently, over 1000 volatile compounds have been identified. Early work suggested that the species differences in flavor are largely explained by differences in lipid-derived volatile components in cooked meat. There have also been several hundred volatile compounds, derived from lipid degradation, that have been identified. They include aliphatic hydrocarbons, aldehydes, ketones, alcohols, carboxylic acids and esters. Some aromatic compounds, especially hydrocarbons, have also been reported, as well as oxygenated heterocyclic compounds such as lactones and alkylfurans (Dransfield, 2008). In general, these compounds result from oxidation of the fatty acid components of lipids. Exposure to air, storage and heating can cause further oxidation of lipid and give rise to ‘stale’, ‘sulfur-rubbery’ and ‘rancid’ off-flavor development including the so-called ‘warmed-over flavor’. The perception of fats and fatty acids may be dependent on a combination of textural, olfactory, nociceptive, thermal, and gustatory modalities. Several approaches have been reported to try and determine the existence of a specific taste for lipid, particularly by attempting to separate any gustatory effect of lipid from oral texture (viscosity) and odor (including orthoand retro-nasal) modalities. In meats, fatty acids are present largely as triglycerides. Kawai and Fushiki (2003) showed that the addition of a lipase inhibitor diminished the spontaneous preference of rodents for triglycerides but not the preference for free fatty acids. However, although lipase could release fatty acids from di- or triglycerides in rats, lipase is present only in small amounts in human saliva. So any mechanism for flavor perception in humans is likely to have to take into account di- and triglycerides (Dransfield, 2008). An alternative approach to unraveling the role of fat perception is to study different sensing organs at the cellular and receptor protein level. At the cellular level, it has been suggested that the mechanism by which taste cells sense dietary fat is by fatty acids delaying the flux through K+-channels. This could form a pathway via apical expression of the membrane fatty acid translocase, CD36, in taste bud cells (Fukuwatari et al., 2003). CD36 serves as a scavenger and lipid receptor (Silverstein and Febbraio, 2000) and functions in recognition of oxidized lipoproteins, fatty acid transport, cell matrix interactions and anti-angiogenic actions.

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

349

Employing different approaches of nutrition, sensory evaluation, neurobiology and cell biology in human and laboratory animal, has given new insights into the mechanisms involved in taste. By comparing the known scavenger and lipid receptor functions of CD36, based largely on animal models, it appears that humans have a specific sensory system for the detection of the taste of fatty acids. This is in addition to the well-recognized ‘five basic tastes’. In particular, sensing their oxidation products of naturally occurring lipids may impact on meat flavors and off-flavors giving rise to a variety of sensory attributes and sensory terms (Dransfield, 2008). The issue of labeling and the terminology used (e.g., ‘fat reduced’, ‘lower in fat’, ‘fat free’) varies quite a lot among different countries, and will not be dealt with in great detail. However it is an important and powerful way to communicate with the customer. In the US, for example, ‘reduced in fat,’ may be used if the individual food contains 25% less fat than the appropriate reference food. The claim must be accompanied by the explanatory information required for relative claims. ‘Free of fat’ or ‘without fat,’ may be used if the food contains less than 0.5 grams of fat per serving (USDA, 2005).

14.3 Consequences of reducing fat in processed meats from an organoleptic and functional perspective As indicated earlier, a straight fat reduction in ground beef-type patties to 10% or below, results in an inferior product. Reitmeier and Prusa (1987) also reported that as fat level was reduced, in pork patties from 23 to 4%, the product became less tender and juicy and had a lower oily mouth coating. Pork flavor was less pronounced in the 4% fat patties. As observed with the beef patties, fat reduction by itself will not likely produce a palatable low-fat pork sausage. The authors suggested that additional ingredients be tried/used to enhance the eating quality of reduced fat products. In a comminuted-type sausage, Bishop et al. (1993) reported that replacing fat (15% of the 30%) with added water prevented the increase in firmness normally associated with low fat bologna. However during storage, accumulated purge in vacuum packages increased with water content in the products, and also with the use of pre-emulsified oil. In terms of modifying processing methods, the authors also tried pre-emulsifying the fat or oil. They indicated that it helped to decrease the firmness of low fat bologna. The color was darker for all the reduced fat bologna except the one preemulsified with corn oil. Flavor and overall acceptability scores, from a consumer sensory panel, did not differ among bologna samples, but juiciness scores were higher in bologna containing additional water. Huffman and Egbert (1990) reported that beef patties produced with approximately 20% fat were highest in overall acceptability over a fat content ranging from 5 to 25%. When changing the particle size they noted that overall palatability of low fat ground beef was slightly improved by a

© Woodhead Publishing Limited, 2011

350

Processed meats

final grind through a 0.48 cm (3/16 inch) plate rather than the more common 0.32 cm (1/8 inch) plate. Huffman and Egbert (1990) and Egbert et al. (1991) have also evaluated the use of a carrageenan gum, in a large-scale study, targeted to bring a new low fat product to the market. They compared beef patties containing 20% fat with those with 8% fat with or without 0.5% iota carrageenan, 10% water, 0.4% encapsulated salt and 0.2% hydrolyzed vegetable proteins. Broiled carrageenan patties with 8% fat were rated more tender by a sensory panel and contained 16% more moisture, 58% less fat, 16% (14 mg/100 g) less cholesterol and 37% (100 kcal/100 g) fewer calories than the 20% fat control. Reducing the fat content to 8% without any additives resulted in patties that were less juicy, had lower flavor intensity, and greater shear force values than either the 20% control or 8% fat-carrageenan patties. Patties with 20% fat had the highest cooking losses but lowest shear force. Serving temperature also appeared to be more critical for low-fat patties than regular fat patties. The McDonald’s Corporation adapted a low fat carrageenan formulation pretty similar to the one described by Huffman and Egbert (1990) and introduced the McLean DeluxTM hamburger in 1991. The product was on the market for several years but then removed, probably due to low sale volumes. It is interesting to note that in consumer surveys, most people would indicate that they would like to buy low fat hamburgers (e.g., when asked in focus groups), but when they enter a fast food restaurant they would actually like to have a more juicy/full flavor hamburger. Since the 1991 introduction, there has been quite a lot of development done in this area by various meat and/or ingredient companies and quality has dramatically improved, but the McLean has not been re-introduced. Overall, the application of any gum : water substitution combination (e.g., water : carrageenan) must be carefully done, otherwise unexpected product changes can negatively affect acceptability. For example, when using carrageenan one must remember that it has a low melting point and it forms a reversible gel (melts at about 50 °C). This can cause premature moisture loss and/or water-soluble flavors; fewer browning reaction products may develop during grilling/broiling, thus reducing meaty flavor (both just after cooking and more so after holding under a fast-food service situation). This is on top of natural variations in carrageenan performance (e.g., the gum is extracted from seaweeds at different locations around the world, refined by different processes, and is affected by the presence of mono- and divalent salts).

14.4 Technological methods to reduce fat Overall, various methods have been tried over the years. One method that has been already mentioned is using leaner raw materials instead of the common trims, so the processor can achieve a 5–10% fat content.

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

351

Another way has been the replacement of fat with water. Pork sausage patties containing 25% fat and 13% added water showed higher cooking losses than 15% or 35% fat patties prepared with 13% added water (Ahmed et al., 1990). However, 15% and 25% fat patties with 3% added water had less cooking losses than their 35% fat counterparts. Generally speaking, it appears that for low-fat patties, the addition of excess water alone may be detrimental to cook yield, juiciness, and tenderness and cause increased springiness and cohesiveness. As with ground beef, added water must be bound to produce a desirable low-fat pork product. In emulsion-type meat product (bologna), formulations ranging from 30% fat (plus 10% added water) to 5% fat (plus 35% added water); all with similar protein content, Claus et al. (1989) observed low-fat, high-added water bologna to be generally softer, juicier, more cohesive, and darker in color with greater cooking and vacuum package purge loss than a control. Regression analysis indicated that bologna with 10% fat would require 24.3% added water to approximate the sensory firmness of the control. The results indicate that water retention and duplication of the textural characteristics of fat become major problems when formulating low fat emulsion products simply by fat substitution with water only. When fat was kept at 14–16%, Park et al. (1990) indicated that processing yields, aroma, flavor, juiciness, and overall desirability of frankfurters containing 14–16% added water with 14–16% fat (∼75% as high-oleic sunflower oil) were equal to or greater than control frankfurters with 29% fat. The effect of heating rate was studied by Cofrades et al. (1997). They compared regular fat level (23%) and low fat (9%; produced with high added water level) in frankfurters heated at 0.55, 1.10 and 1.90 °C min−1. They evaluated moisture binding properties (cooking and purge losses) and texture (compression test). Low-fat frankfurters exhibited poorer (p < 0.05) binding properties, they were less hard and chewy but more cohesive and springy than high-fat frankfurters. Heating rate had little effect on binding properties. Hardness, cohesiveness, springiness and chewiness were greater (p < 0.05) at the slowest heating rate than at the other rates.

14.5 Saturated fat replacement using healthier fats Various researcher groups have investigated the use of different vegetable oils in meat products as animal fat substitutes (Bloukas et al., 1997; Pappa et al., 2000; Tan et al., 2001; Severini et al., 2003). Some vegetable oils contain large amounts of monounsaturated fatty acids (MUFA), and are obviously free of cholesterol. MUFA and PUFA can help decrease plasma low density lipoprotein (LDL). Moreover, a higher level of PUFA can increase high density lipoprotein (HDL) and thus reduce incidences of coronary heart disease (Mozaffarian et al., 2005). Canola oil has one of the lowest levels of saturated fatty acids and linolenic acid of any other conventional vegetable oils and is a good source of the antioxidant tocopherol (Giese, 1996). Some

© Woodhead Publishing Limited, 2011

352

Processed meats

of the canola oil can also be converted to the highly unsaturated omega-3 fatty acid eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) in the body (Gustafsson et al., 1994). It should also be mentioned that McDonald et al. (1989) reported that high consumption of canola oil may increase bleeding time, reduce platelet aggregation and alter plasma and platelet fatty acid composition. Therefore it may inhibit thrombosis; however, this is a dose-related response. Vegetable oils differ considerably in their color, flavor, and fatty acid content which may affect the quality characteristics of meat products. Marquez et al. (1989) reported that low fat frankfurters made with a 60% substitution of the traditional beef fat with peanut oil had lower emulsion stability, firmer texture, and darker color. Hammer (1992) produced frankfurter-type sausages using olive oil and sunflower oil (25% fat level). The products were lighter in color and no processing problems occurred even without the use of non-meat additives such as blood plasma, phosphate, or an emulsifier. Youssef and Barbut (2009) reported that cook loss of emulsified beef frankfurter-type products prepared with canola oil (25%) increased when protein level was raised above 14% (10 to 15% meat proteins used in the formulations). When similar products were prepared with beef fat the effect was reversed. Figure 14.1 shows the general trend when products 25

Fat loss (%)

Percent loss (%)

20

x

15

10

a

y

z

y

c

cd

5

Fluid loss (%)

b

y

z

ef

fg

z

cd

z

de

z gh

z

z hi

ghi

z fg

z hi

z

i

11% MP + 25% HPO

14% MP + 25% HPO

0 8% 11% 14% 8% MP + MP + MP + MP + 25% 25% 25% 25% BF BF BF RBF

11% MP + 25% RBF

14% 8% 11% 14% 8% 11% 14% 8% MP + MP + MP + MP + MP + MP + MP + MP + 25% 25% 25% 25% 25% 25% 25% 25% RBF CO CO CO PO PO PO HPO

z

i

Treatment

Fig. 14.1 Fat and fluid losses from meat batters prepared with 8, 11 and 14% meat protein. (MP, meat protein; BF, beef fat; RBF, rendered beef fat; CO, canola oil; PO, palm oil; HPO, hydrogenated palm oil).a–i Means related to fluid loss with no common superscript are significantly different (P < 0.05); error bars indicate the standard error.x–z Means related to fat loss with no common superscript are significantly different (P < 0.05); error bars indicate the standard error. From Youssef and Barbut (2010); with permission.

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

353

were produced with 8, 11 and 15% protein. Bloukas and Paneras (1993) produced low fat frankfurters using olive oil, but the product had a lower processing yield and overall palatability. Paneras and Bloukas (1994) reported that low fat frankfurters (10% fat, 12.5% protein) made with olive, corn, sunflower or soybean oils showed lower processing yields, darker color, firmer texture, lower juiciness, as well as lower levels of saturated fatty acids, calories and cholesterol than a control (29.1% pork fat, 10.4% protein). Ambrosiadis et al. (1996) reported that replacing the pork back fat with soybean, sunflower, cottonseed, corn, or palmine oil (19.5% level), resulted in good emulsion stability in beef meat frankfurters, but firmness and lightness (internal color) were lower than the control. However, Park et al. (1989) found that replacing animal fat with high-oleic acid sunflower oil and fish oil had little effect on emulsion stability of low fat frankfurters. Hsu and Yu (2002) looked at reducing fat in Kung-wans, which are emulsified meatballs. They had three controls (25% pork back fat, 10% fat and 10% water) and 11 plant oils, including coconut, sunflower, palm, corn, peanut, soyabean, tea seed and olive, and hydrogenated oils from coconut, palm and soyabean were compared. Results indicated that replacing 25% pork back fat with 10% water did not change the textural properties. In general, all plant-oil products had similar textural properties as the control except for tea seed oil and peanut oil, which showed higher textural profile analysis data. Tea and peanut oils were inferior owing to bitter taste and strong odor. Overall, coconut, palm, soyabean, olive, and hydrogenated soyabean oils were better fat substitutes. Palm oil and its derivatives offer another option for animal fat in meat products. Palm oil is easy to use and has the same overall viscosity/consistency as beef fat at ambient temperature, as well as it contains natural antioxidants. In order to simulate the consistency of high melting point fats, palm oil can also be partially saturated, a process called hydrogenation (Babji et al., 1998). Several researchers have examined the effects of substituting animal fat with palm oil in meat products (Babji et al., 1998; Hsu and Sun, 2006). Liu et al. (1991) reported that replacing beef fat with partially hydrogenated palm oil improved the nutrient quality of lean ground beef patties, by reducing cholesterol content without detrimentally affecting the product’s palatability. Understanding the mechanism(s) of different fats/oils stabilization in meat emulsion is of great importance to the industry. When substituting animal fat with vegetable oil, care should be given to potential problems with higher cooking loss and reduced emulsion stability. Youssef and Barbut (2010) reported that replacing beef fat with 25% canola oil, palm oil, hydrogenated palm oil, or rendered beef fat, in high protein meat batters caused instability with some of the fats/oils (Fig. 14.1). As indicated earlier, canola oil resulted in significantly higher cooking losses as protein level was raised. The fact that no differences were found between the regular and rendered

© Woodhead Publishing Limited, 2011

354

Processed meats

beef fat treatments may suggest that the collagenous network around the fat cells does not contribute to fat holding; however, fat hardness plays an important role in the emulsion stability (i.e., difference between liquid canola oil and beef fat/palm oil). When protein content was reduced to 8%, small fat losses started to appear in the beef fat, rendered beef fat, and palm oil treatments. However, it should be mentioned that 8% is a very low level and not used for practical reasons, as well as because of legal requirements in countries such as Canada (e.g., required a minimum of 11% protein). Raising the amount of meat proteins reduced fat and fluid losses in the beef fat, rendered beef fat, and palm oil containing batters. It is assumed that a high protein level formed a denser protein network within the batter, and helped restrict fat and fluid migration out of these products (microstructure results provided in the paper support this assumption). It could also be that an increase in protein content resulted in more side chains capable of interacting with water molecules during heating, and thus improve yield. The microstructure of the canola oil treatment with 14% protein revealed fat globules that coalesced and the presence of channels (within the protein matrix) which ultimately allowed fat to exudate. It appears that as protein level was raised, the thickness and rigidity of the interfacial protein film around fat globules increased (authors measured higher protein content in the creamy layer of the canola oil treatments). During heating, this thick and rigid protein film probably did not allow fat expansion and this resulted in rupture of fat globules and destabilization of the meat emulsion. Jones and Mandigo (1982) proposed a model showing that as the protein coat around fat globules gets thicker it becomes less flexible and prone to rupture during heating. The emulsion instability of the canola oil treatment prepared with 14% proteins (Fig. 14.1) did not occur in the other treatments probably due to the lower protein content in their creamy layer and/or the larger size of their fat globules. Saffle (1968) also stated that a straight-line relationship was found between protein concentration and emulsifying capacity, until the system became overloaded. For hydrogenated palm oil Fig. 14.1 shows that there was no significant difference in cook loss across all protein levels. This is most probably related to the high melting point of hydrogenated palm oil (60 °C) compared with the canola oil (−12 °C) and beef fat, as well as the structure of the triglycerides within the fat/oil used. The results illustrate the importance of the physiochemical property of the fat/oil used and the need to understand the relationship between the proteins and lipid phase. In dry fermented meat products there are different requirements from the fat/oil used. Muguerza et al. (2001) produced six Chorizo de Pamplona, a traditional Spanish fermented sausage, by replacing 0, 10, 15, 20, 25 and 30% of pork backfat with pre-emulsifying olive oil; using soy protein isolates for pre-emulsification. Sausages with 10–25% substitution were acceptable from a sensory point of view. It was concluded that up to 25% of pork backfat could be replaced with pre-emulsified olive oil. Higher replacement

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

355

levels were unacceptable due to considerable dripping of fat during the ripening process. Cholesterol content showed a reduction of about 12% in sausages with 20–25% replacement level as well as a significantly lower saturated fatty acid level. Del Nobile et al. (2009) used a different approach to add and retain olive oil to replace pork back fat in dry Italian salami. They used whey proteinbased crumb or white breadcrumb to absorb the oil. Five types of salamis were manufactured, under commercial conditions, by replacing 0 (control), 60% and 100% of pork backfat with whey protein-based crumb (WP60, WP100) and white pan bread (PB60, PB100). Results indicated that pH, weight loss, colour and microbial counts did not significantly change between the control and the modified salamis. Modified salamis resulted in a better fatty acid profile (lower saturated and higher monounsaturated fatty acids) than the control. The control showed the highest values for Warner–Bratzler shear, hardness, cohesiveness, gumminess, and chewiness. Sensory evaluation of the WP60 did not show significant differences from the control, whereas PB100 and WP100 were unacceptable for taste. In previous work acceptable dry meat products were developed, reaching a 25% substitution of pork backfat with pre-emulsified soy oil (Muguerza et al., 2003). However, the maximum effective substitution level (with olive oil) proposed in the literature is around 40–50% of the total fat. Higher levels of oil provoked a dripping effect, perspiration through the casings, inhibition of molds, separation of the casing from the meat batter and breaking up of the cured products. For this reason, the proposed new strategies of using the whey protein-based crumbs, to retain higher content of olive oil, seems to be of great interest.

14.6 Alternative fat-replacing ingredients This section represents most of the work that has been done over the past two to three decades in regards to fat reduction/replacement in meat products. It mainly includes the application of various non-meat ingredients (e.g., carbohydrate, proteins) that can contribute/mimic fat sensation in processed meats. Some of the non-meat ingredients have been tested on their own but most have been tested in combination with others as each one can potentially cover certain aspects of fat reduction. In practice, most reduced fat products on the market today contain a combination/mixture of a few ingredients to compensate for the low/no fat in the original product. Carbohydrate-based ingredients include starches, hydrocolloid gums, maltodextrins, and dextrins and are used to modify product’s texture, improve cooking yield, increase moisture retention, reduce formulation cost and improve freeze–thaw stability (Keeton, 1994; Lucca and Tepper, 1994; Barbut, 2002). Overall, gums are used by the food industry to regulate viscosity, form gels, stabilize emulsions, suspend particulates, control

© Woodhead Publishing Limited, 2011

356

Processed meats

crystallization, inhibit syneresis, and encapsulate particulates. In some early studies Wallingford and Labuza (1983) reported xanthan gum to be more effective than carrageenan, locust bean gum and low methoxy pectin in preventing water loss from a low-fat meat emulsion model system. Whiting (1984) noted that alginate or xanthan gums (0.1–0.3%) improved water binding in low-fat frankfurters but were detrimental to gel strength. Foegeding and Ramsey (1986), however, concluded that kappa and iota carrageenan at levels of <1% were the most beneficial for holding moisture and increasing hardness of 11.5% fat frankfurters. Hedonic scores indicated that low-fat frankfurters with iota/kappa carrageenan were as acceptable as the 27% fat control frankfurter. Carrageenan has been one of the ingredients evaluated as a fat replacer in low fat hamburger patties (Egbert et al., 1991) as has been indicated before (Section 14.3) in the development of the McLean product. Barbut and Mittal (1992) have also investigated the effects of kappa and iota carrageenans and xanthan gum on the quality of reduced fat pork sausage (17 to 8%; water added to keep the protein level constant in all products). Iota carrageenan and xanthan gum retained more moisture than kappa carrageenan or products with no gum. Fat reduction resulted in higher cohesiveness, gumminess, and chewiness values, which were not overcome by the gums. In any case, kappa carrageenan formulation provided a more tender product than the other low fat products. Xanthan gum (0.5%) resulted in good fat and moisture retention during cooking; however, it was detrimental to textural parameters and sensory acceptability. Ordonez et al. (2001) compared three low fat products: a sausage with 15% fat and 0.5% carrageenan, a sausage with 10% fat and a combination of 0.5% carrageenan plus 0.4% apple pectin, and a sausage with 10% fat and a combination of 0.5% carrageenan plus 0.1% carboxymethyl cellulose (CMC). Results indicated that low fat frankfurters with a texture profile similar to standard frankfurters could be manufactured through the addition of mixtures of proteins and hydrocolloids. The combination of carrageenan with CMC or apple pectin was more efficient than the use of carrageenan alone; both combinations allow a higher fat reduction, at the same time achieving a final texture well liked by consumers. Xiong et al. (1999) studied the production of low fat (4%) beef sausages with 23% added water, and compared them with a regular fat control (25%) as well as comparing the use of 1.0 or 2.5% salt, 0.5% of different polysaccharide gums, and pH adjusted meats to 5.2, 5.6 or 6.2. The iota and kappa carrageenans increased (P < 0.05) cooking yield, hardness, and bind strength in the 1.0% salt sausage, but had little effect on the 2.5% salt sausage. Sausages containing alginate, locust bean gum, and xanthan gum were softer, more deformable, crumbly, and slippery, when compared with non-gum controls. It appears that in this experiment, the fat level was too low for this kind of product, and most gums could not compensate for it. As has been shown in this review, several ingredients/gums have been found beneficial

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

357

when used as texture-modifying compounds in sausage products. However, some do not perform well. Among possible factors which could hinder the application of certain gums, in commercial meat processing, is the incompatibility between salt-soluble muscle proteins and various polysaccharides especially under high-salt conditions (Tolstoguzov, 1991); also shown by the Xiong et al. (1999) report. The production of low fat Kung-wan, an emulsified meatball (1% vs. 20% fat), with 13 different gums was reported by Hsu and Chung (1999). Replacing fat with water resulted in lower cooking yield, smaller diameter, inferior sensory qualities and lower texture profile analysis indices. Eight gumhydrates produced Kung-wan with higher cooking yields than the 20% fat control. Seven gum-hydrates produced low fat Kung-wan with similar texture profile analysis indices as the control. Six gum-hydrates produced products with similar sensory qualities as the control. Overall, kappa carrageenan, sodium alginate with CaCO3, curdlan gum, and locust bean gum appeared to be good fat substitutes for making low fat emulsified Kung-wan. Konjac flour is another hydrocolloid gum which forms a strong hydrophilic elastic gel. It is claimed to have some of the sensory properties of fat and can provide a substantial reduction in calorie content. Osburn (1992) incorporated rehydrated konjac gel into a 10% fat prerigor pork sausage at levels of 0, 10, or 20% (0.00%, 0.25%, and 0.50% konjac on a dry weight basis) and compared to sausages with 40% fat. Konjac-containing patties were redder in color, similar to controls in overall appearance, and slightly detectable at the 20% level. In comparisons with the 40% fat control, patties with 10% konjac had 3% greater cook yield, were rated only slightly higher for shear force, springiness, cohesiveness, chewiness, hardness, denseness, and fracturability and slightly lower for juiciness. Some konjac gels are translucent and should be colored to avoid pigment absorption from the muscle tissues resulting in a ‘blood splash’ appearance. In addition, seasonings and ingredients can be included in the gel to avoid flavor voids. It was also noted that during pan frying surface browning did not occur without caramel coloring in the seasoning mix. Using a mixture of ingredients to develop an ultra-low fat bologna (<2% fat) was reported by Chin et al. (2000). They evaluated two levels (0.5% or 1.0%) of konjac blends (KB; KSS = konjac flour/starch; KNC = konjac flour/ carrageenan/starch) and the replacement of meat proteins with 2% soy protein isolate (SPI). Increased levels of KB decreased (P < 0.05) most texture profile analysis values as well as lightness and yellowness. Bologna containing 1.0% KB with 2% SPI showed texture profile analysis values and sensory flavor/taste attributes similar to the control (30% fat). However, based on sensory evaluation, low fat bologna formulated with KSS had textural characteristics more similar to the control than those with KNC. Starches and maltodextrins are glucose polymers typically derived from corn, oats, potatoes, rice, tapioca and waxy maize. Upon hydration, two

© Woodhead Publishing Limited, 2011

358

Processed meats

polymeric forms (i.e., amylose and amylopectin), create a three-dimensional gel network that can entrap water. Most fat replacement starches are pregelatinized to enable cold water swelling which is an important feature in binding water prior to the meat protein denaturation. Starches can also improve freeze–thaw stability in meat products, reduce syneresis and resist high shear or heat conditions. Maltodextrins are created by cleaving starch amylose and amylopectin chains and typically have a dextrose equivalent of >20. These ingredients are relatively inexpensive and form a fat-like gel when hydrated. Berry and Wergin (1993) incorporated 8% modified pregelatinized potato starch gel (3% starch, 5% water) in beef patties with 4% or 20% fat. Starch-treated patties had lower sensory flavor and juiciness scores, higher tenderness ratings, improved cook yields (4–6%), and a cost advantage due to the price of the starch. In a slightly different study, Minerich et al. (1991) formulated ground beef patties (10, 15, and 30% fat) with and without 0, 15, or 30% Minnesota wild rice. As the rice level increased, proportional decreases in cholesterol, fat, protein, and ash content were observed. Patties with rice, regardless of fat level, had higher cook yields, lower oxidation and were preferred by consumer panelists over regular ground beef. Troutt et al. (1992) concluded that a three-way combination of polydextrose, potato starch, and either sugar beet, oat, or pea fiber reduced firmness and cohesiveness of 5% and 10% fat beef patties when compared with a 20% fat control. The ingredient combination lightened raw patty color and reduced cooking losses (by 20–40%), beef flavor intensity, juiciness, and oily mouth coating scores. The authors recommended further research to optimize the use of these ingredients in beef patties because high level use can result in reduced firmness and cohesiveness, lightened color, as well as reductions in beef flavor intensity and juiciness. The use of maltodextrin as a fat replacer in reduced fat (30 to 12 and 5%) frankfurters was reported by Crehan et al. (2000). Reducing the fat from 30 to 5% increased cook loss and decreased emulsion stability. Panelists detected a decrease in overall texture, and overall acceptability as well as an increase in juiciness when the fat level was reduced from 30 to 5%. Instron texture profile analysis showed a decrease in hardness, chewiness, and gumminess and an increase in springiness with decreasing fat level. Maltodextrin addition caused a significant decrease in cook loss but also decreased the emulsion stability. An interactive effect was seen between fat level and maltodextrin resulting in no significant difference in hardness, gumminess, and chewiness values when maltodextrin was present in the reduced-fat frankfurters. The authors concluded that maltodextrin can be used as a suitable fat replacer since it offset some of the changes brought about by fat reduction, (i.e. decreasing cook loss and maintaining a number of textural and sensory characteristics of the frankfurters). Odio (1989) identified modified waxy maize starch (MWMS), tapioca dextrin (TADE), and rice flour (RIFL) to have potential as fat substitutes when added to low-fat (9% or 15% fat) frankfurters at 2.5 to 5.0% levels.

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

359

Frankfurters containing MWMS, TADE, and RIFL were found to have similar flavor and texture profiles except for a slight starch flavor at the 9% fat level. Slightly lower cook yields (1–2%) were noted for MWMS, RIFL, and TADE at the 5% level, however, by increasing the smokehouse relative humidity to >50% this problem could likely be resolved. Enzyme modified potato starch (MPS) was evaluated at 2 and 4% as a fat replacer in reduced-fat (30 to 15 and 10%) emulsion-type sausage (Liu et al., 2008). The 15 and 5% fat sausages containing 2% MPS had a similar hardness as the 30% fat control. Sensory evaluation indicated that the presence of MPS, in reduced-fat sausages, increased the product’s tenderness. Overall, the 15% fat sausage with 2% MPS was comparable to the 30% fat control in colour, texture profile, and sensory properties, but was lower in energy, suggesting that the MPS can be used as a potential fat replacer in emulsified sausages. Roller and Swinton (1990) also conducted specific enzymatic modifications (at 65 °C) of potato starch for the production of fat mimetics. The hydrolysed potato starch with dextrose equivalent (DE) of 6.0 was used in laboratory formulated full-fat and low-fat sausages, which compared favorably with commercial samples when assessed by a trained panel. Overall, some starches can help provide the mouthfeel of high fat emulsions in low-fat or fat-free products and lend a glossy, fat-like appearance (Tharanathan, 2005). The advantages of enzyme-modified starches are that they can have specific functional and sensory properties compared with other carbohydrate-based products on the market (e.g., unmodified starches, fiber-based materials). Certain enzyme-modified potato starches can perform well in high moisture foods, such as meat emulsion-type sausages. Some new commercial starch preparations, recently introduced on the market, claim that they are miscible with fat/oil and other food components and can form a thermo-stable gel with a smooth, fat-like texture and natural taste. Shand (2000) examined the potential use of different carbohydrates in ultra-low fat (<1%) meat products. This study was not dealing with fat reduction per se (i.e., no comparison to high fat products), but rather with the production of sausages that would qualify to be labeled as no-fat products according the Canadian regulations (<1% fat). The products were produced with 55% lean meat and about 40% water to achive this ultra-low fat level in this so-called bologna. Adding 4% hull-less waxy barley flour or meal provided the greatest purge control; 4% normal barley starch, wheat flour and potato starch were intermediate; 0.25% kappa-carrageenan or 1% soy protein concentrate had little effect on water holding and texture. Formulations with wheat flour and waxy barley meal were scored the firmest, while bologna with potato starch required the highest force to compress. For most sensory properties, barley fractions performed similarly to wheat flour; however, waxy barley provided superior water holding during storage. Since the emphasis in that study was on the retention of added water, cold

© Woodhead Publishing Limited, 2011

360

Processed meats

and hot absorption of the different binders was assessed separately. The soy protein concentrate showed little difference between absorption in cold water and in hot water (75 °C) with 5% NaCl; 550 and 600%, respectively. Cold absorption of the various carbohydrate-based binders was relatively low. However, potato starch showed the highest hot absorption of all binders tested (1100% vs. 25% in cold water absorption). Native potato starch had a much lower pasting temperature than wheat, which may have led to its higher hot water absorption. Waxy barley meal had the highest hot water absorption among the barley samples (700%) and this may be due to its soluble fiber content and/or starch composition. Another approach is the utilization of preformed gels prepared by polysaccharides, and/or non-meat proteins which are later incorporated into meat products as a fat replacer system. Lyons et al. (1999) evaluated various combinations of such preformed gels. They reported that mixed gels containing high gelling whey protein concentrate (8%) and carrageenan (1.5%), with dry addition of tapioca starch (3%) produced final low-fat (<3% fat) pork sausages with similar characteristics to those of full-fat (20% fat) controls. On the other hand, addition of preformed gel and tapioca starch had a significant negative interactive effect on cook loss, and showed a significant positive linear effect for mechanical textural values. Increasing levels of preformed gel blends with tapioca starch resulted in a general decrease in flavor intensity and overall flavor scores. It should also be mentioned that there are several patents describing such a technology. The use of pork skin or rind has also been evaluated as a fat replacer in reduced fat products. Abiola and Adegbaju (2001) reported that replacing pork back-fat with rind decreased refrigeration and cooking weight losses. Overall, values obtained for sensory properties decreased with increase rind levels in the sausage. However, up to 66% pork back-fat could be replaced with rind in pork sausage without adverse effect on processing yield. Osburn et al. (1997) indicated that pre-heating (70 °C) pork skin connective tissue (PCT) increased water binding. Gels (with 100–600% added water) were formed by heating PCT (70 °C) for 30 min. Higher added water levels increased gel moisture content, while decreasing fat, melting points, collagen content, and hardness. Addition of PCT gels in bologna decreased hardness and increased juiciness, indicating the potential of PCT gels as water binders and texture-modifying agents. Non-meat proteins have been traditionally used as binders and/or extenders to improve yields (water and fat binding), reduce formulation costs, maintain nutritional value, enhance functional properties (viscosity, texture), as well as decrease fat and cholesterol content. In ground beef products some of the most frequently used protein-based fat replacements include texturized and granular forms of soy proteins (flour, concentrate, or isolate), dairy (non-fat dry milk, caseinates, and whey proteins), and wheat flours/gluten. Singly or collectively, most flours (50% protein level) and concentrates (70% protein) are commonly used at levels

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

361

up to 3.5% (dry weight basis) and hydrated at 3 parts water to 1 part protein. Isolates (90% protein) are limited in the USA to 2% (dry weight basis) of the total product formula and hydrated at a 4 : 1 basis (Keeton, 1994). It should be noted that it is essential to achieve full protein hydration and some soy protein preparations require high shear mixing (can usually be assessed by the transformation from a dull to a shiny paste). Sofos and Allen (1977) reported that acceptable wiener-type products could be produced with 45–50% lean, 15–20% fat, 5% hydrated (1 : 4) soy protein isolate (SPI), and 25–30% hydrated (1 : 2) textured soy protein (TSP), but shrink and moisture loss would likely be high. The combined effects of carbohydrate and protein-based ingredients have been studied by various researchers since they can usually better mimic the mouthfeel and textural characteristics of a regular fat product. Protein-based fat replacements appear to offer several advantages to low fat products; however, improvements to textural characteristics (reduced cohesiveness, hardness, and springiness) are still required. Carballo et al. (1995) examined the combined effects of fat reduction (7 to 22%), starch (0 to 10%) and egg white addition (0.6 to 3.0%) into a bologna-type sausage while employing a surface response methodology approach to study those combined effects. Of the three variables studied, starch most influenced binding and textural properties. Starch reduced cooking loss, purge loss during storage, as well as increased hardness, chewiness, and penetration force. Egg white helped to increase hardness, chewiness, and penetration force but did not affect binding properties. Each individual variable was generally not influenced by the other two (Fig. 14.2). Using this kind of surface response approach allows evaluation of the cumulative effect of different additives, which is helpful when using several ingredients at the same time. Claus and Hunt (1991) reported on using isolated soy protein, oat fiber, pea fiber, commercial dietary fiber, wheat starch, and modified starch to enhance the textural and sensory characteristics of low fat (10%) high water added (30%) bologna. Test products were, less firm than the high-fat control but more firm than the low-fat control. Fiber-containing bolognas were more grainy and less juicy than the high fat control. Commercial dietary fiber and oat fiber had greater cooking losses than the low-fat control, but purge was reduced by all test ingredients, particularly modified starch. Lower vacuum level in packages also resulted in less purge. The author concluded that ‘test ingredients had beneficial effects on properties of low-fat, high added-water bologna, thus providing a way to alter product characteristics’. Oat bran or oat fiber has been also evaluated by themselves or in combination with other ingredients. Overall, it appears suited as a fat replacer, up to a certain point, in ground beef and pork sausage products due to its ability to retain water and emulate the particle definition in ground meat in terms of both color and texture. However, overuse or misuse of oat bran/ oat fiber can result in poor binding of the raw product causing difficulties

© Woodhead Publishing Limited, 2011

Processed meats (a)

(b)

1.5

51 0.0

5.0 10.0 Starch (%)

0.0

)

(%

(%

ch

0.0

ar

14.5 22.0 Fat (%)

3.0

71

St

0 7.0

5.0

91

ite

10.0

30

111

wh

60

131

g

90

Hardness (N)

151

120

)

Hardness (N)

150

Eg

362

(c)

126

86

0.0

(%

ite

wh

14.5 22.0 Fat (%)

g

66 7.0

3.0 1.5

)

106

Eg

Hardness (N)

146

Fig. 14.2 Effect of fat, starch and egg white levels on hardness of bologna sausage using a surface response methodology: (a) fat and starch levels at 1.5% egg white; (b) starch and egg white levels at 14.5% fat; (c) fat and egg white levels at 5% starch. From Carballo et al. (1995); with permission.

with patty formation (reduced particle binding), reduced raw color appearance and stability, as well as a crumbly or mealy texture after cooking. Therefore, careful formulation and selection of flavour enhancers are required to retain the meat flavour and texture equal to that of regular fat ground beef. Revised cooking procedures are also needed to avoid overcooking and loss of juices, creating palatability problems, and rejection of low-fat ground beef. Piñero et al. (2008) reported on the beneficial effect of using an oat fiber source of β-glucan (13% homogenate) in low fat (>10%) beef patties as compared with 20% fat control patties. Significant improvements in cooking yield (74%), retentions of fat (79%), and moisture (48%) seen in the low fat patties were attributed to the water-binding ability of β-glucan. Low fat patties received a lower degree of likeness in the taste panel, but were reported juicer than control. Appearance, tenderness, and color were not affected by the addition of oat’s soluble fiber. The author suggested that oat fiber could be used successfully as a fat substitute in low fat beef patties.

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

363

The evaluations of barley β-glucan (0.3 and 0.8%) and CMC (0.3%) in reduced fat breakfast sausage (22 to 12% fat) was reported by Morin et al. (2004). Barley β-glucan is a non-starch polysaccharide that shows potential to be used as a fat replacer in low fat sausages. It is a watersoluble hydrocolloid that functions to provide water control by thickening and/or gelling. As a soluble fiber component, β-glucan has the health benefits of reducing blood serum cholesterol. Cook loss results showed that β-glucan held more water in the sausages than the control mainly because of its ability to form a tighter network (physical entrapment of water) within the meat protein matrix (shown by scanning electron microscopy). Overall, the water-holding capacity of muscle proteins is largely dependent on the reactive groups available to form the protein matrix. Cheftal et al. (1985) suggested that owing to CMC’s negatively charged polyelectrolytic features, it prevents a strong protein network from forming, resulting in a lower cook yield, as water is easily able to move out. Based on Morin et al. (2004) results, it appears that CMC was not as effective, as it interfered with protein network formation, by partially remaining in the spaces between the muscle fiber cells. The β-glucan treatments demonstrated a higher cook yield since they did not inhibit protein cross-linking. Instead, they formed dense matrices, which had the ability to hold large amounts of water within the protein and fat network. This agrees with Bernal et al. (1987) and DeFreitas et al. (1997) who found that carrageenans increased water-holding capacity and gel strength of meat protein networks due to physical entrapment of water, not because of molecular interactions with meat proteins. The effects of CMC and two types of microcrystalline cellulose (MCC-I and II) were investigated in low fat (13 vs. 26%) frankfurters (Barbut and Mittal, 1996). Fat was replaced with water in the low fat products. Moisture loss during cooking was reduced in low fat products from 10 to 6% due to CMC addition; however, both MCC increased overall moisture loss by 12–15%. Product hardness, brittleness, gumminess, and chewiness increased with the decrease in fat level. MCC-II improved the textural properties of the low fat product over those of the high fat product. Sensory panel results indicated a decrease in tenderness with low fat and this was not improved by MCC-II. The viscoelastic properties (relaxation time, elastic moduli) were not found to be affected by the fat reduction. Lin et al. (1988) examined the use of four types of CMC with varying degrees of substitution (DS) and molecular weights (250,000 to 700,000) in low fat, high moisture and high protein frankfurters. Generally speaking, as the CMC molecular weight decreased, the emulsion stability also decreased; however, processing yield and proximate composition of the products were not significantly affected by the treatments. With the exception of springiness and cohesiveness, addition of the CMC significantly decreased the textural parameters, but there were no textural differences in frankfurters due to molecular weights or degree of substitution of the CMC. The ability

© Woodhead Publishing Limited, 2011

364

Processed meats

to soften low-fat frankfurters demonstrated the potential for inclusion of CMC in low-fat meat emulsion products. Cofrades et al. (2000) reported on the effects of fat level reduction (30 to 12 and 5%), carrageenan, and oat fiber combination in frankfurters. Overall textural acceptability decreased as fat level was reduced. Carrageenan and oat fiber improved the acceptability of the 12% fat frankfurters, but neither ingredient offset the detrimental effects on texture acceptability when fat was reduced to 5%. Carrageenan and oat fiber differed in their effects on texture profile analysis values but the latter was more effective at improving texture. The results demonstrate that carrageenan and oat fiber can partially offset some of the textural changes which occur in low fat frankfurters when added water replaces fat and the protein level remains constant. The results also emphasize the point that there is a limit to fat reduction. An 8–10% limit is currently used by quite a few meat companies in their production of reduced fat meat products that should also withstand the tough cost constraints in this highly competitive market of emulsified meat products (bologna, hotdogs). The use of dietary fiber has been on the rise over the past few years as fiber is known to reduce the risk of colon cancer, obesity, cardiovascular diseases, and several other disorders. Several dietetic fibers have also been used in meat products as potential fat substitutes. Inulin is a soluble dietary fiber composed of a blend of fructose polymers extracted from plants with a degree of polymerization ranging from 2 to 60. It has been used as a fat substitute mainly in non-meat foods (cakes, chocolates, dairy products, spreads) because of its contribution to better mouthfeel, enhanced flavor, and low caloric value (1.0 kcal/g) (Izzo and Franck, 1998). Nowak et al. (2007) replaced fat with inulin and also studied the effects of substituting citrate for phosphate in a traditional German-type Mortadella. Fat was replaced with increasing amounts of inulin (used as a frozen gel) to yield 3%, 6%, 9%, and 12% inulin in the final product. Replacing fat with inulin led to significant energy content reductions of up to 47.5% (with 12% inulin). However, the sensory properties were also different from those of the control; fracturability fell, hardness and adhesiveness rose, and color became darker. However, the substitution of citrate for phosphate significantly reduced the negative effects of inulin. The sensory attributes (texture, color) of the 6% inulin-citrate sausages were comparable to the control sausages, and the sausages were microbiologically stable for three weeks of storage. The study illustrates the overall point that certain dietary fibers, such as inulin, can be useful, in maintaining the organoleptic qualities of fat, and also contribute other health benefits (Beylot, 2005). Technologically important is the fact that inulin improves the stability of foams and emulsions, and in a gel form it also displays exceptional fat-like characteristics. Franck (2002), for example, also suggested that inulin can be used to give meat products a creamier and juicier mouthfeel without compromising taste and texture.

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

365

Fat reduction in dry fermented sausages is usually more difficult because replacement of fat by lean meat further increases the hardness of the product due to the high water loss during ripening and drying. Mendoza et al. (2001) used inulin in low fat, dry fermented sausages prepared with a 50% and 75% fat reduction. The 75% reduced fat batch was supplemented with different amounts of the soluble dietary fiber as both a powder or in an aqueous solution. Ripening was followed by physico-chemical and microbiological analysis. Sensory analysis indicated an overall improvement in the sensory properties due to a softer texture provided by inulin. Texture profile analysis results for tenderness, springiness, and adhesiveness were similar to the conventional high fat sausage. Thus, with the addition of inulin a low calorie product (30% of the original), enriched with soluble dietetic fiber (∼10%) could be produced. In conclusion, various combinations of carbohydrates (e.g., starches, hydrocolloid gums, fiber) have been demonstrated to offer some solutions for fat reduction in meat products either alone or in combination with nonmeat proteins and/or modification in processing conditions. As can be seen in this review the industry continues to look at optimizing ingredient combinations in order to maximize water-binding, textural characteristics, flavor perception, cook yield, and microbial shelf-life.

14.7 Future trends Over the past two to three decades, scientists and product developers have been working on finding ways to reduce fat content and/or improve the fatty acid profile of a variety of meat products. Over the last ten years there has been more pressure on the food industry to come up with improved low/no fat food products (e.g., dairy, baked goods, meat). The formation of an acceptable texture and flavor are essential in gaining market acceptability and sustainability of low fat products. As demonstrated in this review, various carbohydrates, proteins and non-digestive fats have been tried and some combinations have been successful in the marketplace. Work on better understanding the contribution of fat to the rheological and taste characteristics of meat products will continue as well as the search for new ingredients/mixtures. Substitution with vegetable oils is also gaining acceptance in the marketplace. Olive oil, for example, is one of the most monounsaturated vegetable oils. It contains 55–85% monounsaturated fatty acids, 8–25% saturated, and 3–21% polyunsaturated fatty acids and is rich in tocopherols and phenolic substances (antioxidants). It also has a high biological value attributed to its high ratio of vitamin E to polyunsaturated fatty acids content and shows beneficial effects on postprandial lipid metabolism and thrombosis. On the other hand it should be mentioned that some nutritionists actually say that we should be re-thinking dietary saturated fats. Westman (2009) wrote that ‘contrary to popular opinion, the link

© Woodhead Publishing Limited, 2011

366

Processed meats

between dietary fat and human disease is not conclusive, which could mean new opportunities for food formulators, especially in the area of low fat carbohydrate produces/diets’. Whatever the approach is, the positive effects for consumer health should be the main driver. Improving meat products with a simultaneous reduction in fat level, partial replacement of some animal fat with vegetable oils, and the inclusion of beneficial dietary components seems to be the main approaches currently employed. It should also be pointed out that the issue of acrylamide formation might be of a concern in some foods exposed to high temperature (e.g., breaded fried nuggets, breakfast sausage). While fat reduction by itself will not make a difference, the inclusion of more carbohydrates might affect the product. Paleologos and Kontominas (2007) indicated that in precooked breaded chicken products (i.e., not necessarily reduced fat), acrylamide concentrations increased during storage, attaining a maximum (1.36 to 1.80 mg kg−1) between day 15 and day 19. The maximum value was observed in samples packaged under air, and the minimum value was observed under a modified atmosphere mixture of 60% CO2–40% N2. It is possible that such an issue will get more attention in the future.

14.8 Sources of further information and advice The references cited in the chapter range from studies concerning the understanding of fat flavor perception (receptor level) to practical experiments involving the use of various formulations and trying to explain the role of individual ingredients. Ingredient companies also have a large information base that is usually kept confidential, but can sometimes be accessed by the meat industry (some is available on the web). Future developments will be dictated by the marketplace and the ability of the meat industry to deliver products that are perceived to be of high value in terms of texture, flavour, nutrition, and cost.

14.9 References abiola s s and adegbaju s w (2001), Effect of substituting pork backfat with rind on quality characteristics of pork sausage. Meat Sci, 58, 409–412. ahmed p o, miller m f, lyon c e, vaughters h m and reagan j o (1990), Physical and sensory characteristics of low-fat fresh pork sausage processed with various levels of added water, J Food Sci, 55, 625–628. ambrosiadis j, vareltzis k p and georgakis s a (1996), Physical, chemical and sensory characteristics of cooked meat emulsion style products containing vegetable oils, Int J Food Sci Technol, 31, 189–194. babji a s, alina a r, chempaka m y s, sharmini t, basker r and yap s l (1998), Replacement of animal fat with fractionated and partially hydrogenated palm oil in beef burgers, Int J Food Sci Nut, 49(5), 327–332. barbut s (2002), Poultry Products Processing, New York, CRC Press, 256–272.

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

367

barbut s and mittal g s (1992), Use of carrageenans and xanthan gums in reduced fat breakfast sausage, Food Sci Technol, 25, 509–513. barbut s and mittal g s (1996), Effects of three cellulose gums on the texture profile and sensory properties of low fat frankfurters, Int J Food Sci Technol, 31, 241–247. doi: 10.1046/j.1365-2621.1996.00337.x bernal v m, smajda c h, smith j l and stanley d w (1987), Interactions in protein/ polysaccharide/calcium gels, J Food Sci, 52, 1121–1125, 1136. berry b w and leddy k f (1984), Effects of fat level and cooking method on sensory and textural properties of ground-beef patties, J Food Sci, 49, 870– 875. berry b w and wergin w p (1993), Modified pregelatinized potato starch in low-fat ground beef patties, J Muscle Foods, 4, 305–320. doi: 10.1111/j.1745-4573.1993. tb00511.x beylot m (2005), Effects of inulin-type fructans on lipid metabolism in man and in animal models, Brit J Nutr, 93(Suppl 1), S163–S168. bishop d j, olson d g and knipe c l (1993), Pre-emulsified corn oil, pork fat, or added moisture affect quality of reduced fat bologna quality, J Food Sci, 58(3), 484–487. doi: 10.1111/j.1365-2621.1993.tb04306.x bloukas j g and paneras e d (1993), Substituting olive oil for pork for pork backfat affects quality of low-fat frankfurters, J Food Sci, 58, 705–709. bloukas j g, paneras e d and fournitzis g c (1997), Effect of replacing pork backfat with olive oil on processing and quality characteristics of fermented sausages, Meat Sci, 45, 133–144. cáceres e, garcía m l and selgas m d (2008), Effect of pre-emulsified fish oil – as source of PUFA n-3 – on microstructure and sensory properties of mortadella, a Spanish bologna-type sausage, Meat Sci, 80, 183–193. carballo j, barreto g and jiménez-colmenero f (1995), Starch and egg white influence on properties of bologna sausage as related to fat content, J Food Sci, 60(4), 673–677. doi: 10.1111/j.1365-2621.1995.tb06204.x cheftal j c, cug j l and lorient d (1985), Amino acids, peptides and proteins, in Fennema O R (Ed.), Food Chemistry, 2nd ed., New York, Marcel Dekker Inc., 245–369. chin k b, keeton j t, miller r k, longnecker m t and lamkey j w (2000), Evaluation of konjac blends and soy protein isolate as fat replacements in low-fat bologna, J Food Sci, 65(5), 756–763. claus j r and hunt m c (1991), Low-fat, high added-water bologna formulated with texture-modifying ingredients, J Food Sci, 56(3), 643–652. claus j r, hunt m c and kastner c l (1989), Effects of substituting added water for fat on the textural, sensory and processing characteristics of bologna, J Musc Food, 1, 1–21. cofrades s, carballo j and jiménez-colmenero f (1997), Heating rate effects on high-fat and low-fat frankfurters with a high content of added water, Meat Sci, 47(1–2), 105–114. cofrades s, hughes e and troy d j (2000), Effects of oat fibre and carrageenan on the texture of frankfurters formulated with low and high fat, Eur Food Res Technol, 211(1), 19–26. crehan c m, hughes e, troy d j and buckley d j (2000), Effects of fat level and maltodextrin on the functional properties of frankfurters formulated with 5, 12 and 30% fat, Meat Sci, 55(4), 463–469. defreitas z, sebranek j g, olson d g and carr j m (1997), Carrageenan effects on salt-soluble meat proteins in model systems, J Food Sci, 62, 539–543. del nobile m a, conte a, incoronato a l, panza o, sevi a and marino r (2009), New strategies for reducing the pork back-fat content in typical Italian salami, Meat Sci, 81(1), 263–269. doi: 10.1016/j.meatsci.2008.07.026

© Woodhead Publishing Limited, 2011

368

Processed meats

dransfield e (2008), The taste of fat, Meat Sci, 80(1), 37–42. doi: 10.1016/j. meatsci.2008.05.030 egbert w r, huffman d l, chen c-m and dylewski d p (1991), Development of low fat ground beef, Food Technol, 45, 64–71. foegeding e a and ramsey s r (1986), Effect of gums on low-fat meat batters, J Food Sci, 51, 33–36, 46. franck a (2002), Technological functionality of inulin and oligofructose, Brit J Nutr, 87(Suppl 2), 287–291. fukuwatari t, shibata k, iguchi k, saeki t, iwata a, tani k, sugimoto e and fushiki t (2003), Role of gustation in the recognition of oleate and triolein in anosmic rats, Physiol Behav, 78, 579–583. giese j (1992), Developing low-fat meat products, Food Technol, 46, 100–108. giese j (1996), Fats and fat replacers: balancing the health benefits, Food Technol, 50(9), 76–78. grundy s and denke m (1990), Dietary influences on serum lipids and lipoproteins, J Lipid Res, 31, 1149–1172. gustafsson i b, vessby b, ohrvall m and nydahl m (1994), A diet rich in monounsaturated rapeseed oil reduces the lipoprotein cholesterol concentration and increases the relative content of n-3 fatty acids in serum in hyperlipidemic subjects, Am J Clin Nutr, 59, 667–674. hammer g f (1992), Processing vegetable oils into frankfurter-type sausages, Fleischwirtschaft, 72, 1258–1265. hsu s y and chung h-y (1999), Comparisons of 13 edible gum-hydrate fat substitutes for low fat Kung-wan (an emulsified meatball), J Food Eng, 40(4), 279–285. hsu s y and sun l y (2006), Comparisons on 10 non-meat protein fat substitutes for low-fat Kung-wans, J Food Eng, 74, 47–53. hsu s y and yu s h (2002), Comparisons on 11 plant oil fat substitutes for low-fat Kung-wans, J Food Eng, 51(3), 215–220. huffman d l and egbert w r (1990), Chemical analysis and sensory evaluation of the developed lean ground beef products, in Advances in Lean Ground Beef Production. Alabama Agric Exp Sta Bull No. 606, Auburn University, Alabama, USA. hughes e, mullen a m and troy d j (1998), Effects of fat level, tapioca starch and whey protein on frankfurters formulated with 5% and 12% fat, Meat Sci, 48, 169–180. izzo m and franck a (1998), Nutritional and health benefits of inulin and oligofructose conference, Trends Food Sci Technol, 9, 255–257. jiménez-colmenero f (2007), Healthier lipid formulation approaches in meat-based functional foods. Technological options for replacement of meat fats by non-meat fats, Trends Food Sci Technol, 18, 567–578. jones k w and mandigo r w (1982), Effects of chopping temperature on the microstructure of meat emulsions, J Food Sci, 47, 1930–1935. kawai t and fushiki t (2003), Importance of lipolysis in oral cavity for orosensory detection of fat, American J Physiol, Regulatory Integrative and Comparative Physiology, 285(2), R447–R454. keeton j t (1994), Low-fat meat products – technological problems with processing, Meat Sci, 36, 261–276. lin k c, keeton j t, gilchrist c l and cross h r (1988), Comparisons of carboxymethyl cellulose with differing molecular features in low-fat frankfurters, J Food Sci, 53(6), 1592–1595. doi: 10.1111/j.1365-2621.1988.tb07792.x liu h, xiong y l, jiang l and kong b (2008), Fat reduction in emulsion sausage using an enzyme-modified potato starch, J Sci Food Agric, 88, 1632–1637. doi: 10.1002/ jsfa

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

369

liu m n, huffman d l and egbert w r (1991), Replacement of beef fat with partially hydrogenated plant oil in lean ground beef patties, J Food Sci, 56(3), 861–862. doi: 10.1111/j.1365-2621.1991.tb05401.x lucca p a and tepper b j (1994), Fat replacers and the functionality of fats in foods, Trends Food Sci Technol, 5, 12–19. lyons p h, kerry j f, morrissey p a and buckley d j (1999), The influence of added whey protein/carrageenan gels and tapioca starch on the textural properties of low fat pork sausages. Meat Sci, 51(1), 43–53. marquez e j, ahmed e m, west r l and johnson d d (1989), Emulsion stability and sensory quality of beef frankfurters produced at different fat or peanut oil levels, J Food Sci, 54, 867–870, 873. mcdonald b e, gerrard j m, bruce v m and corner e j (1989), Comparison of the effect of canola oil and sunflower oil on plasma lipids and lipoproteins and on in vivo thromboxane A2 and prostacyclin production in healthy young men, Am J Clin Nutr, 50, 1382–1388. mendoza e, garcía m l, casas c and selgas m d (2001), Inulin as fat substitute in low fat, dry fermented sausages, Meat Sci, 57(4), 387–393. minerich p l, addis p b, epley r j and bingham c (1991), Properties of wild rice/ ground beef mixtures, J Food Sci, 56, 1154–1157. morin l a, temelli f and mcmullen l (2004), Interactions between meat proteins and barley (Hordeum spp.) β-glucan within a reduced-fat breakfast sausage system, Meat Sci, 68(3), 419–430. mottram d s (1998), Flavor formation in meat and meat products: a review, Food Chem, 62, 415–424. mozaffarian d, ascherio a, hu f b, stampfer m j, willett w c and siscovick d s (2005), Interplay between different polyunsaturated fatty acids and risk of coronary heart disease in men, Circulation, 111, 157–164. muguerza e, gimeno o, ansorena d, bloukas j g and astiasaran i (2001), Effect of replacing pork backfat with pre-emulsified olive oil on lipid fraction and sensory quality of Chorizo de Pamplona – a traditional Spanish fermented sausage, Meat Sci, 59(3), 251–258. muguerza e, ansorena d and astiasaran i (2003), Improvement of nutritional properties of Chorizo de Pamplona by replacement of pork backfat with soy oil, Meat Sci, 65, 1361–1367. nowak b, von mueffling t, grotheer j, klein g and watkinson b-m (2007), Energy content, sensory properties, and microbiological shelf life of German bolognatype sausages produced with citrate or phosphate and with inulin as fat replacer, J Food Sci, 72(9), 5629–5638. doi: 10.1111/j.1750-3841.2007.00566.x odio e m (1989), Chemical, physical, and sensory characteristics of reduced fat meat batters and products with added carbohydrates, MS thesis, Texas A&M University, College Station, Texas, USA. ordonez m, rovira j and jaime i (2001), The relationship between the composition and texture of conventional and low-fat frankfurters, Int Journal Food Sci Technol, 36(7), 749–758. osburn w n (1992), Evaluation of physical, chemical, sensory and microbial characteristics of low-fat precooked lamb and fresh pork sausages made with konjac flour, MS thesis, Texas A&M University, College Station, Texas, USA. osburn w n, mandigo r w and eskridge k m (1997), Pork skin connective tissue gel utilization in reduced-fat bologna. J Food Sci, 62, 1176–1182. özvural e b and vural h (2008), Utilization of interesterified oil blends in the production of frankfurters, Meat Sci, 78, 211–216. paleologos e k and kontominas m g (2007), Effect of processing and storage conditions on the generation of acrylamide in precooked breaded chicken products. J Food Prot, 70, 466–472.

© Woodhead Publishing Limited, 2011

370

Processed meats

paneras e d and bloukas j g (1994), Vegetable oils replace pork backfat for low-fat frankfurter, J Food Sci, 59, 725–728, 733. pappa i c, bloukas j g and arvanitoyannis i s (2000), Optimization of salt, olive oil and pectin level for low-fat frankfurters produced by replacing pork backfat with olive oil, Meat Sci, 56, 81–88. park j, rhee k s, keeton j t and rhee k c (1989), Properties of low-fat frankfurters containing monounsatured and omega-3 polyunsaturated oils, J Food Sci, 54, 500–504. park j, rhee k s and ziprin y a (1990), Low-fat frankfurters with elevated levels of water and oleic acid, J Food Sci, 55, 871–872. doi: 10.1111/j.1365-2621.1990. tb05255.x piñero m p, parra k, huerta-leidenz n, arenas de moreno l, ferrer m, araujo s and barboza y (2008), Effect of oat’s soluble fibre (β-glucan) as a fat replacer on physical, chemical, microbiological and sensory properties of low-fat beef patties, Meat Sci, 80, 675–680. doi: 10.1016/j.meatsci.2008.03.006 rakosky j (1970), Soy products for the meat industry, J Agr Food Chem, 18, 1005–1009. reitmeier c a and prusa k j (1987), Cholesterol content and sensory analysis of ground pork as influenced by fat level and heating, J Food Sci, 52, 916–918. roller s and swinton s (1990), Enzymes and the food industry: the role of the Leatherhead Food Research Association. Food Sci Tech Today, 4, 111–114. saffle r l (1968), Meat emulsions, Adv Food Res, 16, 105–160. severini c, pilli t d and baiano a (2003), Partial substitution of pork backfat with extra-virgin olive oil in ‘salami’ products: effects on chemical, physical and sensorial quality, Meat Sci, 64, 323–333. shand p j (2000), Textural, water holding, and sensory properties of low-fat pork bologna with normal or waxy starch hull-less barley, J Food Sci, 65(1), 101–107. silverstein r l and febbraio m (2000), CD36 and atherosclerosis, Current Opin Lipidol, 11, 483. sofos j n and allen c e (1977), Effects of lean meat source and levels of fat and soy protein on the properties of wiener-type products, J Food Sci, 42, 879–885. tan s s, aminah a, affandi y m s, atil o and babji a s (2001), Chemical, physical and sensory properties of chicken frankfurters substituted with palm fats, Int J Food Sci Nutr, 52, 91–98. teye g a, wood j d, whittington f m, stewart a and sheard p r (2006), Influence of dietary oils and protein level on pork quality, Meat Sci, 73, 166–177. tharanathan r n (2005), Starch – value addition by modification, Crit Rev Food Sci Nutr, 45, 371–384. troutt e s, hunt m c, johnson d e, claus j r, kastner c l and kropf d h (1992), Characteristics of low-fat ground beef containing texture-modifying ingredients, J Food Sci, 57(1), 19–35. tolstoguzov v b (1991), Functional properties of food proteins and role of protein– polysaccharide interaction, Food Hydrocoll, 4, 429–468. usda (1986), Composition of food: beef products, Agriculture Handbook Number 8–13, United States Department of Agriculture, Human Nutrition Service, Hyattsville, MD. usda (2005), Issues Final Rule On Nutrient Content Claims For Meat And Poultry Products. http://www.fsis.usda.gov wallingford l and labuza t p (1983), Evaluation of the water binding properties of food hydrocolloids by physical/chemical methods and in a low fat meat emulsion, J Food Sci, 48, 1–5. westman e (2009), Rethinking dietary saturated fat, Food Technol, 63(2), 27–34. whiting r c (1984), Addition of phosphate and gums to reduced salt frankfurter batters, J Food Sci, 49, 1355–1359.

© Woodhead Publishing Limited, 2011

Reducing fats in processed meat products

371

xiong y l, noel d c and moody w g (1999), Textural and sensory properties of low-fat beef sausages with added water and polysaccharides as affected by pH and salt, J Food Sci, 64(3), 550–554. doi: 10.1111/j.1365-2621.1999.tb15083.x youssef m and barbut s (2009), Effects of protein level and fat/oil on emulsion stability, texture, microstructure and color of meat batters, Meat Sci, 82, 228–233. youssef m k and barbut s (2010), Physicochemical effects of the lipid phase and protein level on meat emulsion stability, texture, and microstructure, J Food Science, 75(2), 108–114.

© Woodhead Publishing Limited, 2011

15 The use of nutraceuticals in processed meat products and their effects on product quality, safety and acceptability J. Hayes and N. Brunton, Teagasc Food Research Centre, Ireland

Abstract: The development of functional processed meat products with enhanced ‘healthiness’ through the use of nutraceuticals is essential for the industry to compete with other food sectors. While considerable hurdles exist to the development of these products, including consumer resistance to inclusion of health-promoting ingredients into a product perceived as unhealthy, from a technological point of view, incorporation of new ingredients is not difficult. Colour, texture and flavour can be enhanced. This chapter explores evidence for and against the inclusion of nutraceutical ingredients in processed meat products and identifies areas where more research is required if the development of these products is to be successful. Key words: nutraceutical, processed meat, functional food, microbial safety, quality attributes, flavour, sensory acceptability.

15.1 Introduction The formal definition for a processed meat encompasses the processes of smoking, drying, salting, curing, fermenting, pickling, cooking and forming. Processed meat may contain other ingredients but must contain at least 30% meat. The meat must have undergone a method of processing other than boning, slicing, dicing, mincing, or freezing. It includes manufactured meat and cured and/or dried meat flesh in whole cuts or pieces. Examples of processed meats would include some sausages and some frankfurters, ham or prosciutto (Food Standards Australia and New Zealand, 2002). The terms ‘nutraceuticals’ and ‘functional foods’ are used synonymously. A nutraceutical can be defined as the actual substance that confers a health benefit, whereas a functional food is a foodstuff enriched with a healthpromoting compound. The term ‘nutraceutical’ was coined from ‘nutrition’

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

373

and ‘pharmaceutical’ in 1989 by Stephen DeFelice, MD, founder and chairman of the Foundation for Innovation in Medicine (FIM), Cranford, NJ. According to DeFelice, nutraceutical can be defined as, ‘a food (or part of a food) that provides medical or health benefits, including the prevention and/or treatment of a disease’ (Brower, 1998). However, the term nutraceutical as commonly used in marketing has no regulatory definition (Zeisel, 1999). Functional foods have been broadly defined as ‘foods similar in appearance to conventional foods that are consumed as part of a normal diet and have demonstrated physiological benefits and/or reduce the risk of chronic disease beyond basic nutritional functions’ (Clydesdale, 1997). The Food Safety Authority of Ireland (FSAI) briefly defines a functional food as one that ‘may provide added health benefits following the addition/ concentration of a beneficial ingredient or the removal/substitution of an ineffective or harmful ingredient’ (FSAI, 2007). Functional foods already available on the EU market include those with added cholesterol-lowering plant sterols and stanols, as well as those containing live bacteria (probiotics) that allegedly enhance the quality of the human gut microflora. The interest in functional food products has been fuelled by a desire for convenience as well as health. Busier lifestyles mean people are unable to meet their nutritional requirements using traditional food and drinks (Datamonitor, 2007). The global functional foods market continues to be a dynamic and growing segment of the food industry. Functional foods have experienced great success, emerging from a niche market to a mainstream market category. According to Weststrate et al. (2002) a key challenge to ensure the bright future of functional foods is to provide solid guarantees to consumers that they can trust the safety of functional foods and their claims/promises about better health, performance and development or growth. At present, dairy constitutes the largest segment of the functional foods market followed by cereal products and beverages as illustrated in Fig. 15.1. Meat is a relatively small player and is included in the other foods category which in total accounts for 2.2% (Leatherhead Food International, 2006). In recent years, the addition of naturally occurring antimicrobial and antioxidant compounds derived from plant sources to meat products has increased because of their potential health benefits and safety, compared with synthetic derivatives which were routinely used in processed foods. The potential health risks shown to be associated with synthetic antioxidants have prompted strict regulations for their use in foods and, consequently, interest in the development and use of naturally occurring safe alternatives has increased markedly. Oxidative processes such as lipid oxidation and oxymyoglobin oxidation in meat are challenges to the meat industry. Jiménez-Colmenero et al. (2001) suggested several strategies in the development of functional healthier meat and meat products. These strategies included modification of the carcass composition (e.g. dietary

© Woodhead Publishing Limited, 2011

374

Processed meats Eggs, 1%

Other, 2% Beverages, 14% Soya, 7%

Dairy, 43%

Cereals, 19% Bakery products, 2%

Fats/oils, 12%

Fig. 15.1 Commodity market share of the global functional food market (Leatherhead Food International, 2006).

intervention, genetic selection, feeding managment) and manipulation of meat raw materials (extensive trimming to remove fat from carcass). Another strategy recommended by Jiménez-Colmenero et al. (2001) was the reformulation of the meat product through the reduction of fat content, modification of fatty acid profile, reduction of cholesterol, reduction of calories, reduction of sodium content, reduction of nitrites and incorporation of functional ingredients. Although all aspects from animal production to product processing should be considered for designing healthier processed meat products, this chapter focuses on the use of nutraceutical or functional ingredients in processed meat products mainly from the viewpoint of product quality, safety and acceptability. The chapter explores the main challenges of such product development focusing on the different factors determining the acceptance of functional foods.

15.2 Nutraceuticals and processed meats A wide variety of nutraceutical components have been added to meats and the major categories are summarised in Table 15.1. Each of the components added will have different effects both on the quality and nutritional value of the final product. Historically some components have been added to meats to deliver a technological function and their bio-active potential has only emerged in more recent times. For example, traditionally the meat industry has utilised natural antioxidants found in binders, herbs and spices

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

375

Table 15.1 Examples of major classes of bioactive nutraceutical components Bioactive component

Examples

Lipids and fatty acids

n-3 Polyunsaturated fatty acids (eicosapentaenoic and docosahexaenoic acids), monounsaturated fatty acids, conjugated linoleic acid Soy protein, bioactive peptides (inhibitors of the angiotensin I-converting enzyme, carnitine, anserine, etc.) Dietary fibres (soy, oats, citrus, etc.) oligosaccharides Lactic acid bacteria (Lactobacillus casei, L. acidophilus, etc.), bifidobacteria Tocopherols, folic acid, ascorbic acid Calcium, magnesium, selenium, zinc, iron Phytosterols (sterol and stanol esters), carotenoids (β-carotene, lycopene, lutein, zeaxanthin, lutein, etc.), flavonoids (flavones, flavones, catechins, etc.), phytoestrogens (isoflavones)

Proteins and peptides Prebiotic Probiotic Vitamins Minerals Phytochemicals

as additives in meat products. However, until recently, there has been limited research into meat as a functional food while functional foods in the dairy sector have been developed to a high degree. Meat is considered less allergenic than many other foods and a lot more research into the development and marketing of novel functional meat products is required (Arihara, 2006). The formulation of foods according to the beneficial effects that non-nutritional ingredients may have for the consumer has become an area of interest for large food companies, including the meat sector (Vasconcellos, 2001). Functional meat products are unconventional and consumers in many countries do not recognise meat and meat products as healthy, unlike milk and dairy products (Arihara, 2004). Further research is needed to demonstrate the benefits of meat and meat components and along with scientific data there is an urgent need to inform consumers of the exact functional value of meat (Arihara, 2004).

15.2.1 Implications of meat for human health Meat and poultry products are seen as a food category with both positive and negative nutritional attributes. Meat is considered a vital component of a healthy diet, essential minerals particularly iron, an excellent source of protein, containing all essential amino acids (lysine, theronine, methionine, phenylalanine, typtophan, leucine, isoleucine and valine) as well as trace elements and vitamins (National Health and Medical Research Council, 2006). Red meat, in particular, is an important source of micronutrients with anticancer properties, including selenium, vitamin B6 and B12 and vitamin D (Donaldson, 2004). Meat also contains potential anticarcinogens, including; omega-3 polyunsaturated fatty acids (Divisi et al., 2006) and conjugated

© Woodhead Publishing Limited, 2011

376

Processed meats

linoleic acid (CLA) (Belury, 2002; Maggiora et al., 2004; Mandir & Goodlad, 2008). Meat plays a critical role in maintenance of human health a subject which has been the focus of many extensive review articles (Verbeke et al., 1999; Jiménez-Colmenero et al., 2001, 2006; Arihara, 2004, 2006; Desmond & Troy, 2004; Fernandéz-López et al., 2005; Valsta et al., 2005; Schmid et al., 2006). Meats and processed meats in particular are also associated with nutrients and nutritional profiles that are often considered negative, including high levels of saturated fatty acids, cholesterol, sodium, high fat and caloric contents (Whitney & Rolfes, 2002; Lam et al., 2009). Negative concerns regarding meat consumption and its impact on human health have prompted research into development of novel functional meat products (Arihara, 2006). Some of the negative nutrients in meat can be minimised by selection of lean cuts, removal of adipose tissue, dietary manipulation of fatty acid compositions and proper portion control to decrease fat consumption and caloric intake (Decker & Park, 2010).

15.2.2 Strategies for achieving healthier meat and meat products The meat industry is one of the most important in the world and, whether as a result of consumer demand or because of the strong competition in the industry, research into new products is ongoing. In recent years, a greater emphasis has been placed on the link between diet and the prevention of chronic diseases and the idea of using food for health purposes rather then nutrition opens up a new field for the meat industry. Meat products are one of the most commonly consumed foods and offer an excellent means of promoting intake of functional ingredients without any major changes in eating habits (Cofrades et al., 2008). Also, the increase in younger consumers with disposable incomes who are more likely to experiment with new meat products and who have non-traditional eating habits is contributing to the demand for more added-value processed meat products (Mintel, 2003). Meat-based functional foods are seen as an opportunity to improve the image of meat products and to address the needs of consumers, as well as to update nutrient dietary goals (Jiménez-Colmenero, 2007; FernándezGinés et al., 2005). Both meat and meat products can be modified by adding functional ingredients considered beneficial for health or by eliminating or reducing components that are thought to be harmful. The addition of bioactive compounds with antioxidant activity to meat would make it a potential functional food (Arihara, 2006; Jiménez-Colomenero et al., 2006). The introduction of functional ingredients such as natural antioxidants, botanicals, plant extracts, seaweeds and whey proteins with probable biological activity into processed meat products has, and continues to receive abundant attention (McCarthy et al., 2001; Ribnicky et al., 2008; Calvo et al., 2008; Hernández-Hernández et al., 2009; Cofrades et al., 2008; Hayes et al., 2005). Adjusting the balance between meat and other dietary components may be critical to protecting against potential cancer risks (Ferguson, 2010).

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

377

The main parameter considered in a study on the development of functional meat products by Reglero et al. (2008) was the benefit/risk ratio, raising the benefits to a maximum and decreasing the risks to a minimum, at the same time. To increase the benefits, the following statements according to Reglero et al. (2008) have to be considered: • Search for extensive physiological benefits. For instance, antioxidants (Demmig-Adams & Adams, 2002) and polyunsaturated fatty acids (PUFAs) (Jump, 2004) ingested through diet can influence gene expression. • To guarantee bioavailability. In vitro tests can be used to select the functional ingredients prior to animal assays and clinical trials. • Test integrity maintenance. Analytical techniques and biological assays can be used to ensure the chemical and biological integrity of the functional ingredients after processing operations, during preservation time and cooking. To reduce risks, the layout is as follows: • To use commonly consumed food products as natural ingredients. It is important to use ingredients occurring naturally in foods (Ibánez et al., 2003) obtained using mild transformation techniques (Torres et al., 2003) or preparations with well-defined food activities, extracted from natural sources (Jaime et al., 2005) • To add the minimum effective dosage of functional ingredients. • To perform an exhaustive characterisation of the product. It is important to ensure that negative chemical changes have been avoided or detect the presence of residues or contaminants (Mendiola et al., 2005). Considering that most of the functional ingredients are extracts, the possibility of concentrating toxic compounds along with the main product should be eliminated. • To carry out toxicity studies at higher dosage than those used in the formulation to guarantee the absence of negative side effects (Anadon & Martinez-Larranaga, 1990).

15.3 Product quality The design and development of functional meat products should not be carried out purely based on the desired nutritional function without taking product properties such as colour, texture, taste and mouthfeel into consideration. In general the appearance and sensory properties of foods are more important attributes to the consumer than nutritional values. Demonstration of successful and effective incorporation of bioactives into selected food matrices is important for the commercialisation of new bioactives and functional food ingredients (Day et al., 2009). For soft solid foods such as meat products, the structure-derived quality aspects such as stability, texture

© Woodhead Publishing Limited, 2011

378

Processed meats

and taste are of high importance for consumer acceptance of foods as well as for the bioavailability of micronutrients (Parada & Aguilera, 2007). Choosing a fortification route through the addition of a bioactive has resulted in a number of technical challenges for food manufacturers associated with choice of unit processes to maintain not only the biological functionality of the bioactive, but also the quality and sensory attributes of the food (Day et al., 2009). The physiological benefits of nutraceuticals are achieved only if the meat product is consumed and the bioactive substance is present at the required concentrations. If these conditions are not met due to change in product quality during storage, the nutraceutical or functional food loses its beneficial effect. Challenges remain to ensure that functional ingredients survive and remain ‘active’ and ‘bioavailable’ after food processing and storage. Following the addition of nutraceutical compounds to meat products it is also important to conduct a control experiment containing no nutraceutical compounds to guarantee the integrity of the formulation during processing, cooking and preservation under refrigerated storage conditions. The addition of nutraceuticals to processed meats has been shown to affect a large number of quality attributes and has been an extensive area of research over the last decade. Table 15.2 summarises some of the components that have been studied in processed meats and the quality attributes they have affected. As is evident from Table 15.2, lipid oxidation is one of the main factors limiting the quality and acceptability of lipid containing foods as it affects the sensory quality, due to off-flavour (warmedover-flavour) and off-odour development, and the production of potentially toxic compounds (Morrissey et al., 1994). One of the most effective ways to minimise lipid oxidation and hence warmed-over-flavour in cooked meats is the use of exogenous antioxidants. Colour changes are also a significant factor influencing the quality and acceptability of meat and meat products. Therefore, delaying lipid oxidation and product enhancement are factors that can make a significant contribution towards the development of processed meat products containing nutraceuticals with enhanced nutritional benefits, improved shelf-life and superior product quality. Plant-derived ingredients possessing antioxidant properties have the advantage of being readily accepted by consumers, as they are perceived as ‘natural’. As well as increasing lipid stability in muscle foods, nutraceutical antioxidant addition to a food may also result in antioxidant activity in the body once digested, thus reducing the risk of various diseases related to the presence and subsequent reduction of free radicals (Bravo, 1998).

15.3.1 Effect of added nutraceuticals on lipid oxidation Numerous studies have examined the addition of antioxidants to meat products to maintain their properties during storage or to improve their health benefits. A lot of research has been carried out examining the effect

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Citrus fibre, rosemary essential oil

Short chain fructo-oligosaccharides

Bologna sausage

Dry fermented sausage Fermented sausage

Tiger nut fibre

Carrot fibre

Pork pattie

Dry fermented sausage Dry fermented sausage Frankfurters, dry fermented sausage Turkey patties, pork sausages Beef pattie

Enhanced fatty acid profile, Na/K ratios, water and fat binding, increased Ca Increased mineral content, enhanced oxidative stability, colour and texture

Wakame seaweed, dog rose extracts

Higher nutritional value, higher cooking yield, fat and moisture retention Did not modify physicochemical and sensory parameters Antioxidant effect

García-Iñiguez de Ciriano et al. (2009) Lopéz-Lopéz et al. (2009a,b); Valencia et al. (2007); Lee et al. (2006a,b); Wan Rosli et al. (2006) Lopéz-Lopéz et al. (2010); Ganhão et al. (2010)

Eim et al. (2008)

Yilmaz & Gecgel (2009); Selgas et al. (2005) Aleson-Carbonell et al. (2005); Besbes et al. (2008); Piñero et al. (2008) Sánchez-Zapata et al. (2009)

Miliauskas et al. (2007)

Antioxidant activity Enhanced fatty acid profile, fibre enriched Enhanced cook yield and fat retention, enhanced antioxidant effect

Salazar et al. (2009)

Fernandez-Lopez et al. (2007); Viuda-Martos et al. (2010b) Viuda-Martos et al. (2010b)

Reference

Lower lipid oxidation decrease in residual nitrite level, did not modify sensory properties Lowered the levels of residual nitrite and the extent of lipid oxidation Reduced hardness, higher acceptabilty

Outcome

Algal oil, olive oil, sea spaghetti

Borage leaf extract

Citrus fibre, β-glucans, Pea fibre, wheat fibre

Sausages, beef pattie

Meat balls, sausages

Orange fibre, oregano essential oil

Dry cured sausage

Geranium macrorrhizum, Potentilla fruticosa and Rosmarinus officinalis Inulin

Nutraceutial/functional ingredients

Examples of recent published articles on processed meat products containing added nutraceuticals

Processed meat product

Table 15.2

© Woodhead Publishing Limited, 2011

Continued

Frankfurters Chicken patties Fermented sausage

Ground goat and beef meat

White peony, red peony, sappanwood, moutan peony, rehmania, angelica and rosemary extracts Whey protein Pomegranate juice and rind extract Lb. paracasei LTH 2579

Tea catechins Resveratrol, citroflavan-3-ol, olive leaf extract and Echinacea purpurea Peanut skin extract Grapeseed and bearberry extracts Rosemary extract, omega-3 PUFA, salmon oil, vitamin E Wheat fibre Walnut

Beef patties Lamb patties

Beef patties Pork patties Frankfurters, cooked ham, turkey Fish products Restructured steak

Sage, oregano Green tea, grapeseed extract

Green tea catechins, green coffee antioxidant, fish oil Lutein, sesamol, ellagic acid, olive leaf extract

Nutraceutial/functional ingredients

Beef patties Beef patties

Sausage, pork and beef patties

Sausages

Processed meat product

Table 15.2

Reduced the cook loss and tenderness Protection against oxidative rancidity No effect on the technological or sensory properties

Reduced lipid oxidation Decreased lipid oxidation Enhanced fatty acid profile, higher antioxidant activity Increased water holding capacity Improvement in antioxidant status, a reduction in thrombogenesis markers Strong antioxidant activity

Reduced lipid oxidation, enhanced nutritional properties Suppressed lipid oxidation, ellagic acid, lutein and sesamol exhibit cytoprotective and/or genoprotective effects as added ingredients in pork patties Exhibit bioactivity Reduced microbial spoilage and lipid oxidation Enhanced lipid stability and colour Resveratrol and citroflavan-3-ol decreased lipid oxidation

Outcome

Hayes et al. (2005) Naveena et al. (2008) Pidcock et al. (2002)

Sánchez-Alonso et al. (2007) Jiménez-Colmenero et al. (2010) Han and Rhee (2005)

O’Keefe & Wang (2006) Carpenter et al. (2007) Reglero et al. (2008)

Liu et al. (2010) Nieto et al. (2010)

Ryan et al. (2009) Bañón et al. (2007)

Hayes et al. (2010a,b, 2011); Daly et al. (2010)

Valencia et al. (2008)

Reference

The use of nutraceuticals in processed meat products

381

of the polyphenols contained in citrus fibre at concentrations of 2–10% on lipid oxidation in both meat and fish-based products, whether cooked (Fernández-Ginés et al., 2003; Fernández-López et al., 2004; Viuda-Martos et al., 2008; Sánchez-Zapata et al., 2009) or dry-cured (Alesón-Carbonell et al., 2005; Fernández-López et al., 2007). Various phytochemical extracts, essential oils and common herbs such as borage, sage, oregano, rosemary have been shown to have significant antioxidant activity at levels of 0.02–3% in processed meat products (Sánchez-Escalante et al., 2003; Fasseas et al., 2008). The antioxidant effect on meat and fish products of the essential oils of spices (levels up to 1%) in general and oregano in particular is generally accepted (Viuda-Martos et al., 2008, 2010a; Atrea et al., 2009). Tea catechins (300 mg/kg) (McCarthy et al., 2001; Tang et al., 2001) and various carotenoids at concentrations of 100–580 μg/g (Calvo et al., 2008; Hayes et al., 2010a,b, 2011) have also been used to enhance oxidative stability in meat products. The use of functional starter cultures with antioxidant properties due to catalase or superoxide dismutase, for instance Staphylococcus carnosus, may help to inhibit lipid oxidation and prevent deterioration of colour and texture as well as the formation of toxic compounds (Barrière et al., 2001).

15.3.2 Effect of added nutraceutical addition on product texture To date, most functional food research has focused on nutritional composition of the food and to a lesser extent the analysis of product quality such as texture is an important part of functional meat product development. Dietary fibres are not only desirable for their nutritional properties but also for their functional and technological properties. In this regard, fibre at levels of up to 7.5% has been successful in improving cooking yield, reducing formulation cost and enhancing the texture of a range of processed meat products (Iyengar and Gross, 1991; Jiménez-Colmenero, 1996; Mendoza et al., 1998; Aleson-Carbonell et al., 2005; Viuda-Martos et al., 2010b). Some authors reported an increase in hardness when fibre is added to various meat products (Backers and Noli, 1997). The addition of orange dietary fibre to bologna sausages led to an increase in the hardness probably because their addition would involve incorporating particles in the protein matrix that would strengthen the binding formed during cooking (Viuda-Martos et al., 2010b). Such an effect was also observed by García et al. (2007) in bologna sausage with added orange, apple or peach fibre at concentrations of 15 and 30 g/kg and by Fernández-Ginés et al. (2003) in bologna sausage with different concentrations (0.5–2%) of orange fibre added. The source of fibre is also important because different plant structures can affect fibre properties. Selgas et al. (2005) found that the addition of a soluble dietary fibre up to 7.5% such as inulin resulted in a significantly softer sausage. The ability of soy protein to contribute to the formation of thermalinduced gels is significant in food applications and in new product

© Woodhead Publishing Limited, 2011

382

Processed meats

development. It has been reported that the addition of soy proteins increases firmness, texture and succulence of the meat products while also reducing the amount of purge (Feiner, 2006), but the effect depends both on the characteristics of the soy protein and on the formulation conditions. The interactions between soy and myofibrillar proteins can produce substantial changes in the structure of meat proteins, causing functional and textural modifications in meat products formulated with added soy protein at concentrations of 3 and 6% w/w (Herrero et al., 2008). Other nutraceutical compounds, for example edible seaweeds, contain various bioactive compounds with potential health benefits and their use as functional ingredients opens up new prospects for food processing and meat product formulations as studied by Cofrades et al. (2008) in low salt gel/emulsion meat systems at levels of 2.5% and 5% dry matter. Seaweeds contain high proportions of polysaccharides along with various other potentially beneficial compounds such as good-quality protein and essential fatty acids, particularly long-chain n-3 polyunsaturated fatty acids (PUFAs) (Fernández-Martín et al., 2009). The physicochemical and textural properties of polysaccharide such as Konjac glucomannan make them ideal fat replacers, and hence they have been used to formulate different types of low fat comminuted meat products at levels from 0.5 to 20% (Osburn and Keeton, 1994; Chin et al., 2000; Kao and Li, 2006) with enhanced textural properties and added health benefits. Lipids and fatty acids are among the bioactive components or functional ingredients that have received abundant interest, particularly with respect to the development of healthier meat products and have been shown to enhance mouthfeel and desirable textural properties (Jiménez-Colmenero, 2001, 2006, 2007; Anandh et al., 2003; Muguerza et al., 2004; Fernández-Ginés et al., 2005; Arhiara, 2006).

15.3.3 Effect of added nutraceutical addition on product colour The addition of nutraceutical compounds can affect product colour and acceptability. For example, the enrichment of beef patties with lycopene affected all colour parameters in both raw and cooked samples following addition of dry tomato peel at concentrations of 0 to 6% w/w (García et al., 2009) and tomato paste and levels of 5 to 15% (Candogan, 2002). The addition of lemon albedo as a source of dietary fibre resulted in a reduction in oxymyoglobin oxidation in bologna sausage following the addition of 0.5–2% citrus fibre (Fernández-Ginés et al., 2003). Although colour changes have been reported as being induced by the presence of fibres of various origins in various meat products in other cases no such effect was observed (Hughes et al., 1997). Oxidative processes are also associated with discoloration of meat products, as lipid oxidation results in the formation of pro-oxidants capable of reacting with oxymyoglobin, which lead to metmyoglobin formation (Frankel, 1998), hence the addition of nutraceutical compounds with

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

383

antioxidant properties could result in the reduction of oxymyoglobin oxidation. The decrease in a* redness values in meat products is attributed to the oxidation of oxymyoglobin to metmyoglobin, resulting in discolouration of the product. Traditionally, antioxidants are added to control discolouration in muscle foods (Bao et al., 2008). Some studies have confirmed that myoglobin oxidation and lipid oxidation are interrelated in meat and the oxidation of polyunsaturated fatty acids catalyses metmyoglobin formation and vice versa (Renerre, 1990; Bao et al., 2008). This theory is supported by research where the addition of nutraceutical compounds (100 to 20,000 μg/g meat) exhibit potent lipid antioxidant activity and a reduction in oxymyoglobin oxidation in meat products (Han and Rhee, 2005; Hayes et al., 2009, 2010a,b, 2011; Andres Nieto et al., 2010). Functional starter cultures offer an additional functionality compared with classical starter cultures and represent a way of improving and optimising the sausage fermentation process and achieving tastier, safer and healthier products (Leroy et al., 2006).

15.3.4 Effect of nutraceutical addition on volatile composition In common with many of the other indices of meat quality, studies on the effect of added health-promoting compounds/extracts on meat volatiles have concentrated on the addition of essential oils and other extracts from herbs and spices. These will of course be rich sources of antioxidant compounds which can be used to control the progress of lipid oxidation in meats. Therefore studies on the effect of added extracts have often concentrated on the effect of the added extract on the production volatiles associated with secondary lipid oxidations such as aldehydes, ketones and alcohols. There is less information available on the carry-over of volatile compounds from the extracts themselves which would be expected to have a significant impact on the sensory profile of the processed meat. For example, Mielnik et al. (2008) studied the effect of aqueous extracts of rosemary, sage and thyme, left as by-product after steam distillation of essential oils on volatile production in marinated turkey thighs. The authors reported that total volatile production was reduced in thighs with the essential oil by-product as a marinade ingredient especially for rosemary by-products. However the volatiles analysed were those associated with lipid oxidation. No attempt was made to detect compounds carried over from the herb addition even though sensory analysis indicated that spicy odour and flavours, presumably originating from the herb decoction, were present (Mielnik et al., 2008). Similarly, Wettasinghe & Shahidi (1999) investigated the effect of 1 and 2% w/w evening primrose meal to cooked comminuted pork and reported that levels of hexanal, a lipid oxidation derived volatile, was reduced by 43.6 to 72.6%. However no investigation into volatiles carried over from the addition of the evening primrose oil meal were undertaken. Garcia-Iñiguez

© Woodhead Publishing Limited, 2011

384

Processed meats

de Ciriano et al. (2009) reported that natural antioxidants from lyophilised water extracts of Borago officinalis (340 ppm) significantly reduced lipid oxidation-derived volatiles (including hexanal) in dry fermented sausages enriched in omega-3 PUFA. Information from other authors, however, does indicate that significant carry-over of aroma-active compounds from addition of added herbs and spices and their essential oils can take place. For example, Tzu et al. (1997) detected six volatiles originating from a herb and spice marinade in pork shank. Estevez et al. (2005) also detected volatile carry-over from herbs and spices in a frankfurter sausages but concluded that lipid-derived volatiles were reduced in the presence of rosemary essential oil at concentrations of 150 to 600 μg/g). As previously described above, most studies in this area have concentrated on the effect of herbs and spices and their extracts on volatile production, however in one study, Economou et al. (2009) measured the production of volatile amines in uncooked chicken meat as an index of the efficacy of nisin–ethylenediaminetetraacetic acid (EDTA) based antimicrobials. They reported that nisin and EDTA alone and in combination reduced volatile amine production. In summary, while analysis of volatile production is often carried out as a measure of the ability added extracts to inhibit off-flavour volatiles associated with lipid oxidation more in-depth investigations are required to determine sensory defects that may arise from the addition of herbs and spices containing potent aroma volatiles.

15.4 Microbial safety Production of foods of animal origin of adequate safety is based on the use of modern hygienic and technological procedures. This is particularly true for processed meats as consumers are particularly sensitive to microbiological concerns in this type of product. In addition, meat is a nutrient-dense medium ideal for many pathogens and spoilage microbes to colonise. This deterioration is accelerated in processed meat products, since processing considerably increases their deterioration. Traditionally synthetic compounds such as nitrites have been used to control microbial contamination in processed meats; however, consumers are increasingly demanding so called ‘clean label products’ in which natural preservatives are preferred (Namiki, 1990). This has led to a proliferation in the last decade of research aimed at examining the effectiveness of components derived from natural products which can both inhibit the proliferation of pathogenic and spoilage organisms and deliver a health-promoting effect (i.e. function as a nutraceuticals). The compounds, extracts and organisms that have been used to this effect can be divided into three categories: (1) extracts and pure compounds derived from plants, (2) antimicrobial peptides derived from cultured microorganisms and (3) combinations between added natural antimicrobials and other post-processing strategies.

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

385

15.4.1 Plant origin This is perhaps the most widely investigated source of natural antimicrobials for processed meats. Within this category spices and essentials oils are by far the most widely investigated. Thus is because this type of component can be complementary to the flavour of the final product and also enhance the product by increasing its health-promoting properties. Plant-derived herbs and spices are generally used in processed meats for flavouring and medicinal purposes. Plant essential oils are rich in polyphenolic compounds and the mechanism of action by which these exert their antimicrobial action is not clear. However, it may be due to their ability to alter microbial cell permeability, thereby permitting the loss of macromolecules from the interior (Bajpai et al., 2008). The format in which the herb/spice is added to the processed meat appears to be of critical importance. Specifically, addition of essential oils and other extracts is often much more effective than direct addition of the herb/spice. In fact in most cases where the intact herb/spice was used no effect on the microbiological stability of the final product was observed. For example, Tzu et al. (1997) examined the effect of a marinade containing herbs and spices on the quality of Chinese marinated and spiced pork shank during storage and reported that total plate and anaerobic count were not significantly different. In addition, Biswas et al. (2006) reported that a spice mix and a curry leaf powder had no effect on the microbiological stability of raw or cooked chicken meat. Chia and Tzu (2000) also reported that spice addition was effective at reducing oxidation but not microbial growth during chill storage of alcohol liquor cured duck thigh. Ying et al. (1998) reported that sausages with essential oil additions showed significantly lower microbial counts during storage than controls or those containing spice powders. Essentials oils and other types of extracts from herbs and spices have in contrast shown considerably more antimicrobial efficacy in processed meats. Carraminana et al. (2008) examined the effectiveness of winter savoury, thyme and rosemary essential oils (EO) for control of growth and survival of experimentally inoculated Listeria monocytogenes serovar 4b (104 cfu/g) among natural flora in minced pork. Winter savory essential oil was comparable to French thyme essential oil in listericidal activity, but rosemary EO was ineffective against L. monocytogenes and aerobic flora in the minced meat model. Jun et al. (2008) reported that a dried extract powder mix of medicinal herbs (mulberry, honeysuckle flowers and Coptis chinensis) gave approximately 1 decimal reduction in total aerobic counts in raw pork patties during storage at 4 °C. Rosemary contains significant amounts of rosmarinic acid, a potent antioxidant and antimicrobial agent, and it is therefore not surprising that a number of studies have demonstrated that extracts from rosemary have good antimicrobial properties in cooked processed meats. For example, Georgantelis et al. (2007) reported that rosemary extracts in combination with chitosan significantly reduced counts of

© Woodhead Publishing Limited, 2011

386

Processed meats

Enterobacteriaceae, Pseudomonas spp., and lactic acid bacteria (LAB). Riznar et al. (2006) examined the effect of oil-soluble rosemary extracts on the microbiological stability of chicken frankfurters and concluded that aerobic plate count were significantly reduced compared with controls, stored at 4 or 12 °C. Not all herbs and spices are effective as inhibitors of microbiological growth. For example Poh and Abu (2000) examined the use of a galangal (Alpinia galanga) a ginger-like herb used Indonesian cooking to control microbial counts in ground raw beef but concluded that counts were not effectively reduced by an extract from the herb. Many authors have concentrated on evaluating the antimicrobial efficacy of herb and spice extracts in culture media as an initial screening step before progressing with studies on the final processed meat product. In many cases the agent which progresses for use in the processed product is a combination of the most potent antimicrobial agents identified to take advantage of any synergistic effects. For example, Huiyun et al. (2009), screened 14 spice extracts against cultured media of Listeria monocytogenes, Escherichia coli, Pseudomonas fluorescens and Lactobacillus sake. Results showed that mixture of rosemary and liquorice extracts was the best inhibitor against all four types of microbes. This extract was then examined as a potential antimicrobial agent in cooked ham slices. The number of L. monocytogenes on ham slices decreased 2.5, 2.6 and 3.0 logs, the mesophilic anaerobic bacteria (MAB) plate counts decreased 2.9, 3.0 and 3.2 logs and the LAB counts decreased 2.4, 2.6 and 2.8 logs (P < 0.05), respectively, after 28-days, using the same level of mixed rosemary/liquorice extract treatment. Kong et al. (2007) screened ethanolic extracts from six herbs and spices against E. coli, P. fluorescens and Lactobacillus plantarum in culture media. On the basis of this a composite extract consisting an equal-volume mixture of Scutellaria, honeysuckle, Forsythia, cinnamon, rosemary and clove oil were added to vacuum-packaged fresh pork, where 1.81- to 2.32-log reductions in microbial counts compared with the control when stored for up to 28 days were noted. Giatrakou et al. (2010) also examined the effect of a combination of antimicrobial agents in this case chitosan and thyme in a chicken-pepper kebab. They reported that aerobic plate counts and counts of LAB, Pseudomonas spp., Brochothrix thermosphacta, Enterobacteriaceae, and yeasts and fungi were significantly reduced during the entire storage period. In addition, to herbs and spices other plant-derived components have also been investigated for their ability to inhibit the growth of spoilage and pathogenic bacteria in processed meats. For example Ahn et al. (2004) investigated the inhibition of E. coli O157 : H7, Salmonella Typhimurium and L. monocytogenes by commercially available grape seed and pine bark (PB) extracts in raw beef mince. Results showed that numbers of E. coli O157 : H7, L. monocytogenes and S. Typhimurium declined by 1.08, 1.24 and 1.33 log cfu/g, respectively, in raw beef mince treated with 1% PB after 9 days of refrigerated storage. Yu et al. (2010) reported that a peanut skin

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

387

phenolic extract had limited effectiveness as an antimicrobial in raw ground beef. Bañón et al. (2007) examined the effect of green tea and grape seed extracts for increasing the shelf-life of low sulphite beef patties. They concluded that both green and grape seed extracts delayed microbial spoilage thus increasing the shelf life of the raw sulphite beef patties by 3 days. A small number of studies have examined the antimicrobial efficacy of extracts from fruits and vegetables. Fernández-López et al. (2005) investigated the antibacterial effect of rosemary, orange and lemon extracts in cooked Swedish-style meatballs. Only the rosemary extract exhibited anti-bacterial effects against LAB and Listeria but not B. thermosphacta in an agar diffusion test. In the product only LAB counts were slightly reduced. Woong and Young (2009) studied the effect of garlic and onion juice on total plate counts of emulsified sausage during cold storage and concluded that use of garlic juice resulted in superior antimicrobial activity compared with onion juice and the control. Sallam et al. (2004) reported that addition of fresh garlic or garlic powder significantly reduced aerobic plate counts in chicken sausage; subsequently, the shelf-life of the product was extended to 21 days. In contrast to the case for plant-derived essential oils it would appear that the apparent antimicrobial activity of garlic is derived from the presence of organosulphur compounds such as diallyl sulphide, diallyl disulphide, s-ethyl cystein and n-acetyl cysteine (Yin and Cheng, 2003). As outlined above spices and essential oils containing phenolic compounds such as cinnamic aldehyde (cinnamon), eugenol (cloves) and thymol (thyme) have been reported to have significant antimicrobial activities in processed meats. However, these essential oil components are only effective against certain microorganisms at high concentrations, which often detracts from the sensory quality of food (Davidson, 2001). Studies have demonstrated that allyl isothiocyanate (AIT), a naturally occurring non-phenolic volatile compound found in plants belonging to the Crucifereae family, effectively inhibits a variety of pathogenic microorganisms when used at low concentrations (Lin et al., 2000). Nadarajah et al. (2005) investigated whether the ability of glucosinolates naturally present in non-deheated mustard flour could serve as a source of allyl and other isothiocyanates in sufficient quantity to kill natural microflora inoculated in ground beef. The natural microflora of the ground beef which developed in vacuum packages was unaffected by the addition of 5% mustard flour but some inhibition was found at higher concentrations. Sensory evaluation of the cooked ground beef showed that there were no significant differences in the acceptability of meat treated with 5 or 10% mustard flour. However, panellists could distinguish untreated controls from mustard treatments, but considered the mustard-treated meat to be acceptable. These results showed that it is possible to use mustard flour at levels of >5–10% to eliminate E. coli O157 : H7 from fresh ground beef.

© Woodhead Publishing Limited, 2011

388

Processed meats

15.4.2 Microorganism-derived antimicrobials Since the discovery of nisin in the 1950s a large variety of antimicrobial peptides have been isolated. However, nisin is by far the most commonly used of this type of bio-preservative and it is produced by some strains of the lactic acid bacterium Lactococcus lactis subsp. lactis. Nisin is now used commercially in foods such as cheeses because of its ability to inhibit the growth of many spoilage and pathogenic bacterial strains. The mechanism of action of antimicrobial polypeptides involves multiple targets; however, the most important of these is the cell membrane where their amphipathic nature allows them to interact directly with microbial cell membrane, causing disrupting which results in leaching out of vital cell components (Hancock, 1997). This compound has been approved for use as a food preservative by the Joint FAO/WHO Expert Committee on Food Additives and granted generally recognised as safe (GRAS) status for use in cheese products in the USA. Lemay et al. (2002) examined the inhibitory effect of nisin in a sausage batter at various levels in mechanically deboned chicken inoculated with a mixed culture of E. coli ATCC 25922, B. thermosphacta. The E. coli population decreased steadily during storage and was close or below detection level (<1 log CFU g−1) for all treatments, including the control, after 14 days. Mastromatteo et al. (2010) reported that nisin significantly inhibited the growth of LAB, Enterobacteriaceae and Pseudomonas species in ostrich patties. Other antimicrobial peptides have also been examined for use in processed meats including Sakacin K and its producer on cooked ham and frankfurter sausages (Hugas, 1998), sakacin P and its producer in vacuumpacked bologna sausages (Kroeckel, 1999), enterocins in cooked ham, paté and frankfurter sausages (Aymerich et al., 2005), pediocin in frankfurter sausages and sliced cooked sausages (Hugas et al., 2002; Mattila et al., 2003) and leucocins and its producer strain (Leuconostoc carnosum 4010). Wang (2003) examined the effect of antimicrobial proteins from porcine leukocytes on Staphylococcus aureus and E. coli in comminuted meats. The antimicrobial proteins were isolated from porcine blood and they found that adding 160 μg/g antimicrobial protein preparation to ground ham meat and sausage mince could significantly (P < 0.05) hurdle viable colony formation of test cultures at 6 and 12 h.

15.4.3 Combination strategies With the advent of ‘hurdle technology’ and the demand for clean label products the use of natural antimicrobials is often combined with novel processing strategies which minimise the severity of processing while still inhibiting the growth of undesirable microorganisms. For example Aymerich et al. (2005) examined the use of high hydrostatic pressue in combination with nisin and lactate salts to increase the shelf-life of cooked ham. A synergistic effect to inhibit a cocktail of L. monocytogenes strains (CTC1010,

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

389

CTC1011 and CTC1034) was observed between potassium lactate, high hydrostatic pressure (400 MPa, 17 °C, 10 min) and low storage temperature when sliced cooked ham was stored for 84 days at 1 °C. The high hydrostatic pressure treatment also proved to be useful to inhibit a cocktail of Salmonella enterica serotypes. Jofre et al. (2007) examined the incorporation of Enterocins sakacin K nisin at 200 AU/cm2, potassium lactate and a combination of nisin and lactate were into active packaging interleavers, and their effectiveness against L. monocytogenes spiked in sliced, cooked ham. Antimicrobial-packaged cooked ham was then subjected to high pressure processing (HPP) at 400 MPa. In non-pressurised samples, nisin plus lactate-containing interleavers were the most effective, inhibiting L. monocytogenes growth for 30 days at 6 °C, with counts that were 1.9 log cfu/g lower than in the control after 3 months. In the other antimicrobial-containing interleavers, L. monocytogenes did not exhibit a lag phase and progressively grew to levels of about 8 log cfu/g. HPP of actively packaged ham slices reduced Listeria populations about 4 log cfu/g in all batches containing bacteriocins (i.e. nisin, sakacin and enterocins. Marcos et al. (2008) examined the effect of HPP (400 MPa for 10 min) and natural antimicrobials (enterocins and lactate-diacetate) on the behaviour of L. monocytogenes in sliced cooked ham during refrigerated storage (1 and 6 °C). The most effective treatment was the combination of HPP, enterocins and refrigeration at 1 °C, which reduced the population of the pathogen to final counts of 4 MPN/g (most probable number/g) after three months of storage, even after the cold chain break. Natural antimicrobials can also be combined with other post-processing strategies such as modified atmosphere packaging. For example, Ntzimani et al. (2010) examined the effect of natural antimicrobials, including rosemary and oregano oil, on the shelf-life of semi-cooked coated chicken fillets stored under vacuum packaging. Based on both microbiological total viable count (TVC) data and sensory (taste attribute) analyses, vacuum packaging in combination with oregano oil gave a shelf-life extension of six days. Schirmer and Langsrud (2010) examined the use of thymol, cinnamaldehyde, allyl isothiocyanate, citric acid, ascorbic acid, a rosemary extract, and a grapefruit seed extract in vacuum packed marinated pork for the control of a range of organisms and concluded that although promising results were found at an in vitro level no effect was observed in the final product. Turgis et al. (2008) examined a combination of natural essential oils (Chinese cinnamon, Spanish oregano, mustard), modified atmosphere packaging and gamma radiation on the microbial growth on ground beef. Mustard essential oil was the most efficient for reducing the total counts of mesophilic aerobic bacteria and eliminating pathogenic bacteria. Irradiation alone completely inhibited the growth of mesophilic aerobic and pathogenic bacteria. The combination of irradiation and essential oil was better for reducing LAB and Pseudomonas. Zhang et al. (2009) examined the antimicrobial activities of spice extracts (clove, rosemary, cassia

© Woodhead Publishing Limited, 2011

390

Processed meats

bark and liquorice) against pathogenic and spoilage bacteria in modified atmosphere packaged fresh pork and vacuum packaged ham slices stored at 4 °C. They concluded that a combination of a mixed rosemary/liquorice extract could effectively inhibit the growth of L. monocytogenes, mesophilic anerobic bacteria and LAB in vacuum packed ham slices after 28 days of chilled storage.

15.5 Acceptability The consumer acceptance of functional foods varies widely depending upon their social, economical, geographical, political, cultural and ethnic backgrounds (Jiménez-Colmenero et al., 2001). Within Europe, Germany, France, the United Kingdom and the Netherlands represent the most important countries within the functional food market. European consumers seem to have been reluctant in adopting functional foods, compared with their Asian and North American counterpart (Siro et al., 2008). While the functional food market has been growing, market acceptance of new functional food products has not lived up to many producers’ expectations, especially in Europe and only in recent times has the EU harmonised the legislation on use of health claims in the marketing of functional food products (Grunert, 2010). Consumer acceptance of functional foods is frequently neglected and has serious bearing for the successful marketing and eventual acceptance of functional foods and has regularly been identified as the decisive factor in the successful marketing of functional foods (Bech-Larsen & Scholderer, 2007). Consumers’ willingness to use functional foods will vary depending on the perceived reward from the particular functional food and the necessity for the actual food (Urala & Lähteenmäki, 2007). Many aspects of the functional foods will influence consumers’ acceptance of the product. Some of these include the food type used as a vehicle for fortification or enrichment, the actual enrichment component, health claims, taste and price as well as socio-demographic influences. Processed meat consumption is frequently associated with a negative image of high fat and high salt which are associated with various diseases such as obesity and high blood pressure, and hence consumption may be avoided by consumers. Consumers tend to prefer functional food concepts with disease-related health benefit in a carrier (food) that already has a healthy image or health positioning history (Van Kleef et al., 2005). This consumer preference could pose difficulties for functional processed meats and therefore the negative health issues surrounding these products should be taken into account and clear benefits for health value of the added functional ingredient should be carefully planned and emphasised (McCarthy & Henchion, unpublished data, 2007). It is very important to

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

391

communicate the notion of ‘positive nutrition’ and focus on what is inherently healthy about foods rather than dwelling on the less favourable content (McCarthy & Henchion, unpublished data, 2007). The functional food market is not solely dominated by companies that traditionally have a healthy image, but also by companies perceived as unhealthy such as Mars in the US, where foods have been launched that ‘better serve the nutrition and well being needs of its consumers’ (Leatherhead Food International, 2006). In a survey of consumers, more than 80% agreed that over the next 5 years they will increase their uptake of functional health products but will also continue to consume indulgent foods. The overlap of health with indulgence is a major trend in the health food market (Kemsley, 2006). This indulgence trend was adopted for burgers in the UK where they were marketed as not a health food but a food of reliable quality. Therefore, the consumers can continue to indulge without feelings of guilt (Mintel 2003). In a review by Brugarolas et al. (2008), certain aspects of consumer behaviour regarding functional meat products were discussed, including an exploratory study in relation to the acceptance of a new functional meat product which incorporated fibre from the citrus fruit industry. It was apparent from this study that the number of functional foods consumed was high, indicating that consumer were familiar with functional food products. The results of the study were optimistic in terms of the market possibilities of functional meat products once the product included a benefit that was clearly perceived by the consumer. By combining consumer insight with scientific and process capabilities, it should be possible to produce functional foods that are regarded not only as healthy and convenient, but also natural and tasty (Grunert, 2010). Research in the area of functional meat products will enable meat processors to make significant progress into the functional food market and increase competitiveness in this area. The manufacture of meat products with health-promoting properties would greatly enhance the perception of meat products by consumers in addition to improving market share. There are still some hurdles in developing and marketing novel functional meat products since such products are unconventional and consumers in many countries recognise meat and meat products to be bad for health. Along with accumulation of scientific data, there is an urgent need to inform consumers of the exact functional value of meat and meat products including novel functional foods (Arihara, 2006). Finally, the market for functional meats is very much in its infancy and constitutes only a very minor proportion of the overall functional foods market. The downside is that it is an area that consumers are not familiar with when seeking out functional foods. However, this presents an opportunity to engage in a relatively unexplored market and this emphasises the need for further research

© Woodhead Publishing Limited, 2011

392

Processed meats

in the area of Irish consumers and their acceptance of functional meat products.

15.6 Future trends The effects of food matrices through product formulation and processing will certainly be an important research and development area for future functional foods if health benefits of bioactives are to be fully utilised (Day et al., 2009). Advances are needed in the development of a deeper understanding of the complex interactions between the components of a meat matrix and the effects of incorporation of added technologically and bioactively functional ingredients under the range of conditions. Within the processed meat product the compositional interactions, processing effects on product structure and understanding of the biochemical and cellular mechanisms of the added nutraceuticals needs to be addressed in order to manufacture functional healthier meat products.

15.6.1 Novel food legislation – authorisation to market new food Compared with dietary supplement ingredients, functional foods are subject to unique regulatory requirements and require different safety criteria. Functional foods are currently governed by the Novel Food and Novel Food Ingredients legislation. In May 1997 the EU introduced new regulation governing ‘novel foods’ that adds further complexity for those wishing to introduce food with active ingredients. Novel foods include food types or ingredients that have not yet been used for human consumption. Functional foods are not subject to prior approval or notification before being placed on the market unless they contain a ‘novel’ ingredient. A novel ingredient is one that has not been consumed to a significant degree in the European Community before May 1997 and is subject to the Novel Food and Novel Food Ingredients Regulations (258/97/EC). A food or food ingredient that has a significant history of consumption in any Member State prior to 15 May 1997 does not fall within the scope of the Novel Food Regulation. However, a history of consumption as or in a food supplement or a food additive is not sufficient on its own to enable a food or food ingredient to be placed on the market in a general foodstuff, without novel food authorisation. A full novel food authorisation involves an initial assessment of a dossier of scientific safety data submitted by the applicant company to a Member State competent authority. Where unanimous agreement by all Member States on the initial assessment is not achieved, the dossier is forwarded to the European Food Safety Authority (EFSA) for an independent safety assessment. The European Commission then drafts a proposal based on the EFSA safety assessment, and where sufficient Member State support

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

393

is not achieved, the decision to authorise or reject the application reverts to the Commission. The EFSA has approved rosemary extract as safe and has permitted its use as an antioxidant in food, expanding application opportunities and increasing its natural appeal. This decision means that rosemary extract will now be added to an official list of acceptable food additives for use in food and gains an E number. Companies can choose to label it as ‘antioxidant: rosemary extract’ to maintain a natural nutritional profile. Recent studies have led to the identification of active polyphenolic compounds in green tea and rosemary and these plant extracts have been successfully commercialised in Japan, Europe and North America even though they are more expensive then synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The regulatory inclusion of rosemary extracts allows high purity extracts to be used as alternatives to synthetic antioxidants in the development of functional foods including meat products.

15.7 References ahn, j., grun, i. u. and mustapha, a. 2004. Antimicrobial and antioxidant activities of natural extracts in vitro and in ground beef. Journal of Food Protection, 67, 148–155. aleson-carbonell, l., fernández-lópez, j., pérez-alvarez, j. a. and kuri, v. 2005. Functional and sensory effects of fibre-rich ingredients on breakfast fresh sausages manufacture. Food Science and Technology International, 11, 89–97. anadon, a. and martinez-larranaga, r. m. 1990. Factors increasing the toxicity of anticoccidial ionophores in poultry. Revue Médecine Vétérinaire, 141, 17–24. anandh, m. a., lakshmanan, v. and anjaneluyu, a. 2003. Designer meat foods. Indian Food Industry, 22, 40–45. andres nieto, a. v., o’grady, m., gutierrez, j. i. and kerry, j. p. 2010. Screening of phytochemicals in fresh lamb meat patties stored in modified atmosphere packs: influence on selected meat quality characteristics. International Journal of Food Science and Technology, 45, 289–294. arihara, k. 2004. Functional foods. In: W. K. Jensen, C. Devine and M. Dikeman, Editors. Encyclopedia of Meat Sciences, Elsevier, Oxford, 492–499. arhiara, k. 2006. Strategies for designing novel functional meat products. Meat Science, 74, 219–229. atrea, i., papavergou, a., amvrosiadis, i. and savvaidis, i. n. 2009. Combined effect of vacuum-packaging and oregano essential oil on the shelf-life of Mediterranean octopus (Octopus vulgaris) from the Aegean Sea stored at 4 °C. Food Microbiology, 26, 166–172. aymerich, t., jofre, a., garriga, m. and hugas, m. 2005. Inhibition of Listeria monocytogenes and Salmonella by natural antimicrobials and high hydrostatic pressure in sliced cooked ham. Journal of Food Protection, 68, 173–177. backers, t. and noli, b. 1997. Dietary fibers meat processing. International Food Marketing Technology, December 4–8. bajpai, v. k., rahman, a., dung, n. t., huh, m. k. and kang, s. c. 2008. In vitro inhibition of food spoilage and foodbourne pathogenic bacteria by essential oil and leaf extracts of Magnolia liliflora Desr. Journal of Food Science, 73, M314–M320.

© Woodhead Publishing Limited, 2011

394

Processed meats

bañón, s., díaz, p., rodríguez, m., garrido, m. d. and price, a. 2007. Ascorbate, green tea and grape seed extracts increase the shelf life of low sulphite beef patties. Meat Science, 77, 626–633. bao, h. n. d., ushio, h. and ohshima, t. 2008. Antioxidative activity and antidiscoloration efficacy of Ergothioneine in mushroom (Flammulina velutioes) extract added to beef and fish meats. Journal of Agricultural Food Chemistry, 56, 10032–10040. barrière, c., centeno, d., lebert, a., leroy-sétrin, s., berdagué, j. l. and talon, r. 2001. Roles of superoxide dismutase and catalase of Staphylococcus xylosus in the inhibition of linoleic acid oxidation. FEMS Microbiology Letters, 201, 181–185. bech-larsen, t. and scholderer, j. 2007. Functional foods in Europe: consumer research, market experiences and regulatory aspects. Trends in Food Science & Technology, 18, 231–234. belury, m. a. 2002. Dietary conjugated linoleic acid in health – physiological effects and mechanisms of action. Annual Review of Nutrition, 22, 505–531. besbes, s., attia, h., deroanne, c., makni, s. and blecker, c. 2008. Partial replacement of meat by pea fiber and wheat fiber: effect on the chemical composition, cooking characteristics and sensory properties of beef burgers. Journal of Food Quality, 31, 480–489. biswas, a. k., kondaiah, n. and anjaneyulu, a. s. r. 2006. Effect of spice mix and curry leaf (Murraya koenigii) powder on the quality of meat and precooked chicken patties during refrigeration storage. Journal of Food Science and Technology, 43, 438–441. bravo, l. 1998. Polyphenols: chemistry, dietary sources, metabolism, and nutritional significance. Nutrition Review, 56, 317–333. brower, v. 1998. Nutraceuticals: poised for a healthy slice of the healthcare market? Nature Biotechnology, 16, 728–731. brugarolas, m., martinez-poveda, a., martinez-carrasco, l. and rodriguez, p. 2008. Consumer behaviour in relation to functional foods: functional meat products. In: Technological Strategies for Functional Meat Product Development, 19–39. Transworld Research Network, Kerala, India. calvo, m. m., garcía, m. l. and selgas, m. d. 2008. Dry fermented sausages enriched with lycopene from tomato peel. Meat Science, 80, 167–172. candogan, k. 2002. The effect of tomato paste on some quality characteristics of beef patties during refrigerated storage. European Food Research and Technology, 215, 305–309. carpenter, r., o’grady, m. n., o’callaghan, y. c., o’brien, n. m. and kerry, j. p. 2007. Evaluation of the antioxidant potential of grape seed and bearberry extracts in raw and cooked pork. Meat Science, 76, 604–610. carraminana, j. j., rota, c., burillo, j. and herrera, a. 2008. Antibacterial efficiency of Spanish Satureja montana essential oil against Listeria monocytogenes among natural flora in minced pork. Journal of Food Protection, 71, 502–508. chia, c. h. and tzu, y. w. 2000. Effects of processing, spice addition and packaging on the quality of alcohol liquor cured duck thigh. Taiwanese Journal of Agricultural Chemistry and Food Science, 38, 262–268. chin, k. b., keeton, j. t. and miller, r. k., longnecker, m. t. and lamkey, j. w. 2000. Evaluation of konjac blends and soy protein isolate as fat replacement in low-fat bologna. Journal of Food Science, 65, 756–763. clydesdale, f. m. 1997. Tea and health. Critical Reviews in Food Science and Nutrition, 37, 691–785. cofrades, s., lópez-lópez, i., solas, m. t., bravo, l. and jiménez-colmenero, f. 2008. Influence of different types and proportions of added edible seaweeds on characteristics of low-salt gel/emulsion meat systems. Meat Science, 79, 767–776.

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

395

daly, t., ryan, e., aherne, a., o’grady, m. n., hayes, j., allen, p., kerry, j. p. and o’brien, n. 2010. Bioactivity of ellagic acid-, lutein- or sesamol-enriched meat patties assessed using an in vitro digestion and Caco-2 cell model system. Food Research International, 43, 753–760. datamonitor 2007. Functional food and drink consumption trends. How to target self medicating consumers with high nutrient products. DMCM 2982. davidson, p. m. 2001. On the nature trail in search of the wild antimicrobial. Food Science and Technology, 15, 55–60. day, l., seymour, r. b., pitts, k. f., konczak, i. and lundin, l. 2009. Incorporation of functional ingredients into foods. Trends in Food Science & Technology, 20, 388–395. decker, e. a. and park, y. 2010. Healthier meat products as functional foods. Meat Science, 86, 49–55. Special Issue: 56th International Congress of Meat Science and Technology (56th ICoMST), 15–20 August 2010, Jeju, Korea. demmig-adams, b. and adams, w. w. 2002. Antioxidants in photosynthesis and human nutrition. Science, 298, 2149–2153. desmond, e. and troy, d. j. 2004. Nutrient claims on packaging. In: W. K. Jensen, C. Devine and M. Dikeman, Encyclopedia of Meat Sciences, Elsevier, Oxford, 903–910. divisi, d., di tommaso, s., salvemini, s., garramone, m. and crisci, r. 2006. Diet and cancer. Acto Biomedica, 77, 118–123. donaldson, m. s. 2004. Nutrition and cancer: A review of the evidence for an anticancer diet. Nutritional Journal, 3, 19. economou, t., pournis, n., ntzimani, a. and savvaidis, i. n. 2009. Nisin–EDTA treatments and modified atmosphere packaging to increase fresh chicken meat shelflife. Food Chemistry, 114, 1470–1476. eim, v. s., simal, s., rosselló, c. and femeni, a. 2008. Effects of addition of carrot dietary fibre on the ripening process of a dry fermented sausage (sobrassada). Meat Science, 80, 173–182. estevez, m., ventanas, s., ramirez, r. and cava, r. 2005. Influence of the addition of rosemary essential oil on the volatiles pattern of porcine frankfurters. Journal of Agricultural and Food Chemistry, 5321, 8317–8324. fasseas, m. k., mountzouris, k. c., tarantilis, p. a., polissiou, m. and zervas, g. 2008. Antioxidant activity in meat treated with oregano and sage essential oils. Food Chemistry, 106, 1188–1194. feiner, g. 2006. Additives: proteins, carbohydrates, fillers and other. In: G. Feiner, Editor, Meat Products Handbook: Practical science and technology, CRC Press, Boca Raton, FL, 89–139. ferguson, l. r. 2010. Meat and cancer. Meat Science, 84, 308–313. fernández-ginés, j. m., fernández-lópez, j., sayas-barbera, e., sendra, e. and pérez-álvarez, a. 2003. Effect of storage conditions on quality characteristics of bologna sausages made with citrus fiber. Journal of Food Science, 68, 710–715. fernández-ginés, j. m., fernández-lópez, j., sayas-barberá, e. and pérez-álvarez, j. a. 2005. Meat products as functional foods: a review. Journal of Food Science, 70, R37–R43. fernández-lópez, j., fernández-ginés, j. m., aleson-carbonell, l., sendra, e., sayas-barberá, e. and pérez-álvarez, j. a. 2004. Application of functional citrus by-products to meat products. Trends in Food Science & Technology, 15, 176–185. fernández-lópez, j., zhi, n., aleson-carbonell, l., pérez-alvarez, j. a. and kuri, v. 2005. Antioxidant and antibacterial activities of natural extracts: alication in beef meatballs. Meat Science, 69, 371–380. fernández-lópez, j., viuda-martos, m., sendra, e., sayas-barberá, e., navarro, c. and pérez-álvarez, j. a. 2007. Orange fibre as potential functional ingredient for drycured sausages. European Food Research and Technology, 226, 1–6.

© Woodhead Publishing Limited, 2011

396

Processed meats

fernández-martín, f., lópez-lópez, i., cofrades, s. and jiménez-colmenero, f. 2009. Influence of adding sea spaghetti seaweed and replacing the animal fat with olive oil or a konjac gel on pork meat batter gelation. Potential protein/alginate association. Meat Science, 83, 209–217. food standards australia and new zealand 2002. Food Standards Code, vol. 2. Canberra: Information Australia. frankel, e. n. 1998. In search of better methods to evaluate natural antioxidants and oxidative stability in food lipids. Trends in Food Science and Technology, 4, 220–225. fsai 2007. Functional food information leaflet, Food Safety Authority of Ireland. http://www.fsai.ie/publications/leaflets/functional_food_leaflet.pdf. ganhão, r., morcuende, d. and estévez, m. 2010. Protein oxidation in emulsified cooked burger patties with added fruit extracts: influence on colour and texture deterioration during chill storage. Meat Science, 85, 402–409. garcía, m. l., caceres, e. and selgas, m. d. 2007. Utilisation of fruit fibres in conventional and reduced-fat cooked-meat sausages. Journal of Science and Food Agricultural, 87, 624–631. garcía, m. l., calvo, m. m. and selgas, m. d. 2009. Beef hamburgers enriched in lycopene using dry tomato peel as an ingredient. Meat Science, 83, 45–49. garcía-iñiguez de ciriano, m. g., garcía-herreros, c., larequi, e., valencia, i., ansorena, d. and astiasarán, i. 2009. Use of natural antioxidants from lyophilized water extracts of Borago officinalis in dry fermented sausages enriched in ω-3 PUFA. Meat Science, 83, 271–277. georgantelis, d., ambrosiadis, i., katikou, p., blekas, g. and georgakis, s. a. 2007. Effect of rosemary extract, chitosan and alpha-tocopherol on microbiological parameters and lipid oxidation of fresh pork sausages stored at 4 degrees C. Meat Science, 76, 172–181. giatrakou, v., ntzimani, a. and savvaidis, i. n. 2010. Combined chitosan-thyme treatments with modified atmosphere packaging on a ready-to-cook poultry product. Journal of Food Protection, 73, 663–669. grunert, k. 2010. European consumers’ acceptance of functional foods. Annals of the New York Academy of Sciences, 1190, 166–173. han, j. and rhee, k. s. 2005. Antioxidant properties of selected Oriental non-culinary/ nutraceutical herb extracts as evaluated in raw and cooked meat. Meat Science, 70, 25–33. hancock, r. e. w. 1997. Peptide antibiotics. Lancet, 349, 418–422. hayes, j. e., desmond, e. m., troy, d. j., buckley, d. j. and mehra, r. 2005. The effect of whey protein enriched fractions on the sensory properties of frankfurters. Meat Science, 71, 238–243. hayes, j. e., stepanyan, v., allen, p., o’grady, m. n., o’brien, n. m. and kerry, j. p. 2009. The effect of lutein, sesamol, ellagic acid and olive leaf extract on lipid oxidation and oxymyoglobin oxidation in bovine and porcine muscle model systems. Meat Science, 83, 201–208. hayes, j. e., stepanyan, v., o’grady, m. n., allen, p. and kerry, j. p. 2010a. Effect of lutein, sesamol, ellagic acid and olive leaf extract on the quality and shelf-life stability of packaged raw minced beef patties. Meat Science, 84, 613–620. hayes, j. e., stepanyan, v., o’grady, m. n., allen, p. and kerry, j. p. 2010b. Evaluation of the effects of selected phytochemicals on quality indices and sensorial properties of raw and cooked pork stored in different packaging systems. Meat Science, 85, 289–296. hayes, j. e., stepanyan, v., allen, p., o’grady, m. n. and kerry, j. p. 2011. Evaluation of the effects of selected plant-derived nutraceuticals on the quality and shelf-life stability of raw and cooked pork sausages. LWT – Food Science and Technology, 44, 164–172.

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

397

hernández-hernández, e., ponce-alquicira, e., jaramillo-flores, m. e. and guerrero legarreta, i. 2009. Antioxidant effect rosemary (Rosmarinus officinalis L.) and oregano (Origanum vulgare L.) extracts on TBARS and colour of model raw pork batters. Meat Science, 81, 410–417. herrero, a. m., carmona, p., cofrades, s. and jiménez-colmenero, f. 2008. Raman spectroscopic determination of structural changes in meat batters upon soy protein addition and heat treatment. Food Research International, 41, 765–772. hugas, m. 1998. Bacteriocinogenic lactic acid bacteria for the biopreservation of meat and meat products. Meat Science, 49(SUL), S139–S150. hugas, m., garriga, m. and monfort, j. m. 2002. New mild technologies in meat processing: high pressure as a model technology. Meat Science, 62, 359–371. hughes, f., cofrades, s. and troy, d. 1997. Effects of fat level, oat fiber and carrageenan on frankfurters formulated with 5%, 12% and 30% fat. Meat Science, 45, 273–281. huiyun, z., baohua, k., youling, l. x. and xu, s. 2009. Antimicrobial activities of spice extracts against pathogenic and spoilage bacteria in modified atmosphere packaged fresh pork and vacuum packaged ham slices stored at 4 C. Meat Science, 81, 686–692. ibánez, e., kubátová, a., senoráns, f. j., cavero, s., et al. 2003. Subcritical water extraction of antioxidant compounds from rosemary plants. Journal of. Agriculture and Food Chemistry, 51, 375–382. iyengar, r. and gross, a. 1991. Fat substitutes. In: I. Goldberg and R. Williams, Editors. Biotechnology and Food Ingredients. Van Nostrand Reinhold, New York, 287–313. jaime, l., mendiola, j. a., herrero, m., soler-rivas, c., santoyo, s., señorans, f. j., cifuentes, a. and ibáñez, e. 2005. Separation and characterization of antioxidants from Spirulina platensis microalga combining pressurized liquid extraction, TLC, and HPLC-DAD, Journal of Separation Science, 28, 2111–2119. jiménez-colmenero, f. 1996. Technologies for developing low-fat meat products. Trends in Food Science and Technology, 7, 41–48. jiménez-colmenero, f. 2007. Healthier lipid formulation approaches in meat – based functional foods. Technological options for meat fats by non-meat fats. Trends in Food Science and Technology, 18, 567–578. jiménez-colmenero, f., carballo, j. and cofrades, s. 2001. Healthier meat and meat products: their role as functional foods. Meat Science, 59, 5–13. jiménez-colmenero, f., sánchez-muniz, f. j., olmedilla-alonso, b. and collaborators 2010. Design and development of meat-based functional foods with walnut: technological, nutritional and health impact. Food Chemistry, 123, 959–967. jiménez-colmenero, f. j., reig, m. and toldrá, f. 2006. New approaches for the development of functional meat products. In: L. Mollet and F. Toldrá, Editors. Advanced Technologies for Meat Processing, Taylor and Francis Group, Boca Raton, FL, 275–308. jofre, a., garriga, m. and aymerich, t. 2007. Inhibition of Listeria monocytogenes in cooked ham through active packaging with natural antimicrobials and highpressure processing. Journal of Food Protection, 70(11), 2498–2502. jump, d. b. 2004. Fatty acid regulation of gene transcription. Critical Reviews in Clinical Laboratory Science, 41, 41–78. jun, h. c., aera, j., bong, d. l., xian, d. l., hyun, p. s. and cheorun, j. 2008. Antioxidant and antimicrobial effects of medicinal herb extract mix in pork patties during cold storage. Korean Journal for Food Science of Animal Resources, 28(2), 122–129. kao, w. t. and li, k. w. 2006. Quality of reduced-fat frankfurters modified by konjac– starch mixed gels. Journal of Food Science, 71, S326–S332. kemsley, d. 2006. Targeting the healthy consumer. Business Insights 2006.

© Woodhead Publishing Limited, 2011

398

Processed meats

kong, b., wang, j. and xiong, y. l. 2007. Antimicrobial activity of several herb and spice extracts in culture medium and in vacuum-packaged pork. Journal of Food Protection, 70, 641–647. kroeckel, l. 1999. Natural barriers for biopreservation. Fleischwirtschaft, 79(1), 67–70. lam, t. m., cross, a. j., consonni, d., randi, g., bagnardi, v., bertazzi, p. a., caporaso, n. e., sinha, r., subar, a. f. and landi, m. t. 2009. Intakes of red meat, processed meat, and meat mutagens increase lung cancer risk. Cancer Research, 69, 932–939. leatherhead food international, 2006. The International Market for Functional Foods: Moving into the Mainstream? Leatherhead, Surrey. lee, s., faustman, c., djordjevic, d., faraji, h. and decker, e. a. 2006a. Effect of antioxidants on stabilization of meat products fortified with n-3 fatty acids. Meat Science, 72, 18–24. lee, s., hernandez, p., djordjevic, d., faraji, h., hollender, r., faustman, c., et al. 2006b. Effect of antioxidants and cooking on stability of n-3 fatty acids in fortified meat products. Journal of Food Science, 71, C233–C238. lemay, m. j., choquette, j., delaquis, p. j., gariépy, c., rodrigue, n. and saucier, l. 2002. Antimicrobial effect of natural preservatives in a cooked and acidified chicken meat model. International Journal of Food Microbiology, 78, 217–226. leroy, f., verluyten, j. and de vuyst, l. 2006. Functional meat starter cultures for improved sausage fermentation. International Journal of Food Microbiology, 106, 270–285. lin, c. m., kim, j., du, w. x. and wei, c. i. 2000. Bactericidal activity of isothiocyanate against pathogens on fresh produce. Journal of Food Protection, 63, 25–30. liu, f., dai, r., zhu, j. and li, x. 2010. Optimizing color and lipid stability of beef patties with a mixture design incorporating with tea catechins, carnosine, and α-tocopherol. Journal of Food Engineering, 98, 170–177. lópez-lópez, i., cofrades, s., ruiz-capillas, c. and jiménez-colmenero, f. 2009a. Design and nutritional properties of potential functional frankfurters based on lipid formulation, added seaweed and low salt content, Meat Science, 83, 255–262. lópez-lópez, i., cofrades, s. and jiménez-colmenero, f. 2009b. Low-fat frankfurters enriched with n-3 PUFA and edible seaweed: effects of olive oil and chilling storage on physicochemical and microbial characteristics. Meat Science, 83, 148–157. lópez-lópez, i., cofrades, s., yakan, s. a., solas, m. t. and jiménez-colmenero, f. 2010. Frozen storage characteristics of low-salt and low-fat beef patties as affected by Wakame addition and replacing pork back fat with olive oil-in-water emulsion. Food Research International, 43, 1244–1254. maggiora, m., bologna, m., ceru, m. p., possati, l., angelucci, a., cimini, a., miglietta, a., bozzo, f., margiotta, c., muzio, g. and canuto, r. a. 2004. An overview of the effect of linoleic and conjugated-linoleic acids on the growth of several human tumor cell lines. International Journal of Cancer, 112, 909–919. mandir, n. and goodlad, r. a. 2008. Conjugated linoleic acids differentially alter polyp number and diameter in the Apc(min/+) mouse model of intestinal cancer. Cell Proliferation, 41, 279–291. mastromatteo, m., lucera, a., sinigaglia, m. and corbo, m. r. 2010. Use of lysozyme, nisin, and EDTA combined treatments for maintaining quality of packed ostrich patties. Journal of Food Science, 75(3), M178–M186. marcos, b., jofre, a., aymerich, t., monfort, j. m. and garriga, m. 2008. Combined effect of natural antimicrobials and high pressure processing to prevent Listeria monocytogenes growth after a cold chain break during storage of cooked ham. Food Control, 19, 76–81.

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

399

mattila, k., saris, p. and tyoonen, s. 2003. Survival of Listeria monocytogenes on sliced cooked sausage after treatment with pediocin AcH. International Journal of Food Microbiology, 89, 281–286. mccarthy, t. l., kerry, j. p., kerry, j. f., lynch, p. b. and buckley, d. j. 2001. Evaluation of the antioxidant potential of natural food/plant extracts as compared with synthetic antioxidants and vitamin E in raw and cooked pork patties. Meat Science, 58, 45–52. mendiola, j. a., maren, f. r., hernendez, s. f., arredondo, b. o., señoráns, f. j., ibañez, e. and reglero, g. 2005. Characterization via liquid chromatography coupled to diode array detector and tandem mass spectrometry of supercritical fluid antioxidant extracts of Spirulina platensis microalga. Journal of Separation Science, 28, 1031–1038. mendoza, e., garcía, m. l., casas, c., fernández, m. f. and selgas, m. d. 1998. Utilización de proteínas como sustitutos de grasas en productos cárnicos. Alimentación, Equipos y Tecnología, 7, 87–92. mielnik, m. b., sem, s., egelandsdal, b. and skrede, g. 2008. By-products from herbs essential oil production as ingredient in marinade for turkey thighs. LWT – Food Science and Technology, 41, 93–100. miliauskas, g., mulder, e., linssen, j. p. h., houben, j. h., van beek, t. a. and venskutonis, p. r. 2007. Evaluation of antioxidative properties of Geranium macrorrhizum and Potentilla fruticosa extracts in Dutch style fermented sausages. Meat Science, 77, 703–708. mintel 2003. Processed meats, bacon and deli products. Irish series Mintel International Group Ltd, London, June 2003, pp. 1–59. morrissey, p. a., buckley, d. j., sheehy, p. j. a. and monahan, f. j. 1994. Vitamin E and meat quality. Proceedings of the Nutrition Society, 53, 289–295. muguerza, e., gimeno, o., ansorena, d. and astiasarán, i. 2004. New formulations for healthier dry fermented sausages: a review. Trends in Food Science and Technology, 15, 452–457. nadarajah, d., han, j. h. and holley, r. a. 2005. Use of mustard flour to inactivate Escherichia coli O157 : H7 in ground beef under nitrogen flushed packaging. International Journal of Food Microbiology, 99, 257–267. namiki, m. 1990. Antioxidant/antimutagens in food. Food Science and Nutrition, 29, 273–300. national health and medical research council 2006. Nutrient Reference Values for Australia and New Zealand. Department of Health and Ageing. naveena, b. m., sen, a. r., vaithiyanathan, s., babji, y. and kondaiah, n. 2008. Comparative efficacy of pomegranate juice, pomegranate rind powder extract and BHT as antioxidants in cooked chicken patties. Meat Science, 80, 1304–1308. nieto, a., o’grady, m., gutierrez, j. and kerry, j. 2010. Screening of phytochemicals in fresh lamb meat patties stored in modified atmosphere packs: influence on selected meat quality characteristic. International Journal of Food Science and Technology, 45, 289–294. ntzimani, a. g., giatrakou, v. i. and savvaidis, i. n. 2010. Combined natural antimicrobial treatments (EDTA, lysozyme, rosemary and oregano oil) on semi cooked coated chicken meat stored in vacuum packages at 4 °C: Microbiological and sensory evaluation. Innovative Food Science and Emerging Technologies, 11, 187–196. o’keefe, s. f. and wang, h. 2006. Effects of peanut skin extract on quality and storage stability of beef products. Meat Science, 73, 278–286. osburn, w. n. and keeton, j. t. 1994. Konjac flour gel as fat substitute in low-fat prerigor fresh pork sausage. Journal of Food Science, 59, 484–489. parada, j. and aguilera, j. m. 2007. Food microstructure affects the bioavailability of several nutrients. Journal of Food Science, 72, R21–R32.

© Woodhead Publishing Limited, 2011

400

Processed meats

pidcock, k., heard, g. m. and henriksson, a. 2002. Application of non-traditional meat starter cultures in production of Hungarian salami, International Journal of Food Microbiology, 76, 75–81. piñero, m. p., parra, k., huerta-leidenz, n., arenas de moreno, l., ferrer, m., araujo, s. and barboza, y. 2008. Effect of oat’s soluble fibre (β-glucan) as a fat replacer on physical, chemical, microbiological and sensory properties of low-fat beef patties. Meat Science, 80, 675–680. poh, b. c. and abu, h. n. h. 2000. Natural antioxidant extract from galangal (Alpinia galanga) for minced beef. Journal of the Science of Food and Agriculture, 80(10), 1565–1571. reglero, g., frial, p., cifuentes, a., garcía-risco, m. r., jaime, l., marin, f. r., palanca, v., ruiz-rodríguez, a., santoyo, s., señoráns, f. j., soler-rivas, c., torres, c. and ibañez, e. 2008. Meat-based functional foods for dietary equilibrium omega-6/ omega-3. Molecular Nutrition and Food Research, 52, 1153–1161. renerre, m. 1990. Review: factors involved in the discoloration of beef meat. International Journal of Food Science Technology, 25, 613–630. ribnicky, d. m., poulev, a., schmidt, b., cefalu, w. and raskin, i. 2008. The science of botanical supplements for human health: a view from the NIH botanical research centers. American Journal of Clinical Nutrition, 87, 472S–475S. riznar, k., celan, s., knez, z., skerget, m., bauman, d. and glaser, r. 2006. Antioxidant and antimicrobial activity of rosemary extract in chicken frankfurters. Journal of Food Science, 71, C425–C429. ryan, e., aherne, a., o’grady, m. n., mcgovern, l., kerry, j. p. and o’brien, n. m. 2009. Bioactivity of herb-enriched beef patties. Journal of Medicinal Food, 12, 893–901. salazar, p., garcia, m. l. and selgas, m. d. 2009. Short-chain fructooligosaccharides as potential functional ingredient in dry fermented sausages with different fat levels. International Journal of Food Science and Technology, 44, 1100–1107. sallam, k. l., ishloroshi, m. and samejima, k. 2004. Antioxidant and antimicrobial effects of garlic in chicken sausage. Lebensmittel-Wissenschaft and Technologie, 37, 849–855. sánchez-alonso, i., haji-maleki, r. and javier borderias, a. 2007. Wheat fiber as a functional ingredient in restructured fish products. Food Chemistry, 100, 1037–1043. sanchez-escalante, a., djenane, d., torresacano, g., beltran, j. a. and roncales, p. 2003. Antioxidant action of borage, rosemary, oregano, and ascorbic acid in beef patties packaged in modified atmosphere. Journal of Food Science, 68, 339–344. sánchez-zapata, e., muñoz, c. m., fuentes, e., fernández-lópez, j., sendra, e., sayas, e., navarro, c. and pérez-alvarez, j. a. 2009. Effect of tiger nut fibre on quality characteristics of pork burger. Meat Science, 85, 70–76. schirmer, b. c. and langsrud, s. 2010. Evaluation of natural antimicrobials on typical meat spoilage bacteria in vitro and in vacuum-packed pork meat. Journal of Food Science, 75, M98–M102. schmid, a., collomb, m., sieber, r. and bee, g. 2006. Conjugated linoleic acid in meat and meat products: a review. Meat Science, 73, 29–41. selgas, m. d., caceres, e. and garcia, m. l. 2005. Long-chain soluble dietary fibres as functional ingredient in cooked meat sausages. Food Science and Technology International, 11, 141–147. siro, i., kapolna, e., kapolna, b. and lugasi, a. 2008. Functional food. Product development, marketing and consumer acceptance – a review. Appetite, 51, 456–467. tang, s., sheehan, d., buckley, d. j., morrissey, p. a. and kerry, j. p. 2001. Anti-oxidant activity of added tea catechins on lipid oxidation of raw minced red meat, poultry and fish muscle. International Journal of Food Science and Technology, 36, 685–692.

© Woodhead Publishing Limited, 2011

The use of nutraceuticals in processed meat products

401

torres, c. f., lin, b., moeljadi, m. and hill, c. g. 2003. Lipase-catalyzed synthesis of designer acylglycerols rich in residues of eicosapentaenoic, docosahexaenoic, conjugated linoleic, and/or stearic acids. European Journal of Lipid Science and Technology, 105, 614–623. turgis, m., han, j., borsa, j. and lacroix, m. 2008. Combined effect of natural essential oils, modified atmosphere packaging, and gamma radiation on the microbial growth on ground beef. Journal of Food Protection, 71, 1237–1243. tzu, y. w., ming, t. c., deng, c. l. and shiu, l. g. 1997. Effects of procedure, spice, herb and anka rice on the quality of Chinese marinated and spiced pork shank. Journal of the Chinese Society of Animal Science, 26, 211–222. urala, n. and lähteenmäki, l. 2007. Consumers’ changing attitudes towards functional foods. Food Quality and Preference, 18, 1–12. valencia, i., ansorena, d. and astiasaran, i. 2007. Development of dry fermented sausages rich in docosahexaenoic acid with oil from the microalgae Schizochytrium sp: influence on nutritional properties, sensorial quality and oxidation stability. Food Chemistry, 104, 1087–1096. valencia, i., o’grady, m. n., ansorena, d., astiasarán, i. and kerry, j. p. 2008. Enhancement of the nutritional status and quality of fresh pork sausages following the addition of linseed oil, fish oil and natural antioxidants. Meat Science, 80, 1046–1054. valsta, l. m., tapanainen, h. and männistö, s. 2005. Meat fats in nutrition: review. Meat Science, 70, 525–530. van kleef, e., van trijp, h., luning, p. and jongen, w. m. 2005. Functional foods: health claim-food product compatibility and the impact of health claim framing on consumer evaluation. Appetite, 4, 299–308. vasconcellos, j. a. 2001. Alimentos funcionales. Conceptos y beneficios para la salud. World Food Science, 1, 1–19. verbeke, w., van oekel, m. j., warnants, n., viane, j. and boucque, ch. v. 1999. Consumer perception. Facts and possibilities to improve the acceptability of health and sensory characteristics of pork. Meat Science, 53, 77–99. viuda-martos, m., fernández-lópez, j., sendra, e., sayas, m. e., navarro, c., sánchezzapata, e. and pérez-alvarez, j. a. 2008. Physical and chemical properties of cooked meat products added with orange juice wastewater and thyme essential oil. In: Proceedings of International Functional Foods Conference, EULAFF/ CYTED (p. 78). Porto, Portugal. viuda-martos, m., ruiz-navajas, y., fernández-lópez, j. and pérez-álvarez, j. a. 2010a. Effect of orange dietary fibre, oregano essential oil and packaging conditions on shelf-life of bologna sausages. Food Control, 21, 436–443. viuda-martos, m., ruiz-navajas, y., fernández-lópez, j. and pérez-álvarez, j. a. 2010b. Effect of adding citrus fibre washing water and rosemary essential oil on the quality characteristics of a bologna sausage. LWT – Food Science and Technology, 43, 958–963. wan rosli, w. i., babji, a. s., aminah, a., foo, s. p. and malik, o. 2006. Vitamin E contents of processed meats blended with palm oils. Journal of Food Lipids, 13, 186–198. wang, f. s. 2003. Effect of antimicrobial proteins from porcine leukocytes on Staphylococcus aureus and Escherichia coli in comminuted meats. Meat Science, 65(1), 615–621. weststrate, j. a., van poppel, g. and verschuren, p. m. 2002. Functional foods, trends and future. British Journal of Nutrition, 88, S233–S235. wettasinghe, m. and shahidi, f. 1999. Evening primrose meal: a source of natural antioxidants and scavenger of hydrogen peroxide and oxygen-derived free radicals. Journal of Agricultural and Food Chemistry, 47, 1801–1812. whitney, e. n. and rolfes, s. r. 2002. Understanding Nutrition, 9th edition, Wadsworth, Belmont, CA.

© Woodhead Publishing Limited, 2011

402

Processed meats

woong, y. p. and young, j. k. 2009. Effect of garlic and onion juice addition on the lipid oxidation, total plate counts and residual nitrite contents of emulsified sausage during cold storage. Korean Journal for Food Science of Animal Resources, 29, 612–618. yilmaz, i. and gecgel, u. 2009. Effect of inulin addition on physico-chemical and sensory characteristics of meatballs. Journal of Food Science and Technology, 46, 473–476. yin, m. c. and cheng, w. s. 2003. Antioxidant and antimicrobial effects of four garlicderived organosulfur compounds in ground beef. Meat Science, 63, 23–28. ying, r. y., ming, t. c. and deng, c. l. 1998. A study of antioxidative and antibacterial effects of different spices in Chinese-style sausage. Journal of the Chinese Society of Animal Science, 27(1), 117–128. yu, j., ahmedna, m. and goktepe, i. 2010. Potential of peanut skin phenolic extract as antioxidative and antibacterial agent in cooked and raw ground beef. International Journal of Food Science and Technology, 45, 1337–1344. zeisel, s. h. 1999. Regulation of ‘Nutraceuticals’. Science, 285, 185–186. zhang, h., kong, b., xiong, y. l. and sun, x. 2009. Antimicrobial activities of spice extracts against pathogenic and spoilage bacteria in modified atmosphere packaged fresh pork and vacuum packaged ham slices stored at 4 °C. Meat Science, 81(4), 686–692.

© Woodhead Publishing Limited, 2011

16 Use of probiotics and prebiotics in meat products K. Arihara and M. Ohata, Kitasato University, Japan

Abstract: In recent years, much research and development has been undertaken on functional meat products. Although utilization of probiotics and prebiotics is the main trend in the development of functional foods, the concept of what constitutes probiotics and prebiotics has not been established in the meat industry. This chapter focuses on probiotics and prebiotics in the development of functional meat products. Together with the scientific basis of probiotics and prebiotics, application of these concepts to meat fermentation is emphasized. Future trends, such as the use of a combination of probiotics and bioactive peptides, in the meat industry are also discussed briefly. Key words: probiotics, prebiotics, functional food, fermented meat, bioactive peptide.

16.1 Introduction Increasing concerns about health have led to an increase in attention to the tertiary function of foods (Sloan, 2008). Tertiary functions are roles of food components in maintaining health and preventing diseases by modulating the physiological system. Foods utilizing or emphasizing such tertiary functions are regarded as functional foods. It is only recently that attention has been paid to the research and development of functional meat products (Arihara, 2004, 2006a, 2006b; Arihara and Ohata, 2008, 2009; FernándezGinés et al., 2005; Jiménez-Colmenero, 2007a, 2007b; Jiménez-Colmenero et al., 2001, 2006). Although utilization of probiotics and prebiotics is one of main trends in the development of functional foods, the terms ‘probiotics’ and ‘prebiotics’ have not been well defined in the meat industry. Probiotics can be considered to be ‘live microorganisms which, when administered in adequate amounts (as part of food), confer a health benefit on the host’ (Stanton et al., 2003). Probiotic foods are regarded as physiologically functional if

© Woodhead Publishing Limited, 2011

404

Processed meats

these products have been satisfactorily demonstrated to beneficially affect one or more target functions in the body, beyond adequate nutritional effects, in a way that is relevant to either an improved state of health and well-being or a reduction of the risk of disease. In the dairy industry, traditional fermented milk products have been rediscovered and reborn as functional (probiotic) foods (Farnworth, 2008; Playne et al., 2003). The use of probiotic lines is one attractive approach for developing functional meat products. Also, traditional fermented meat products (e.g., dry sausages) are being reassessed as probiotic foods. Ansorena and Astiasarán (2007) described the possibilities of novel healthier fermented sausages that could minimize the negative features of meat. The following items were listed for developing such fermented sausages: (1) modification of mineral content, (2) fat modifications, (3) incorporation of fiber into formulation, and (4) utilization of probiotic bacteria. This chapter focuses on the utilization of probiotic bacteria for the development of functional meat products. Along with probiotics, prebiotics and synbiotics will be discussed here.

16.2 Probiotics As described above, probiotics are live microorganisms that confer a health benefit on the host. Probiotic bacteria, mainly intestinal Lactobacillus and Bifidobacterium, and probiotic products, such as fermented dairy products, show various physiological functions (Agrawal, 2005; Stanton et al., 2003). Their representative functions are as follows: • • • • • • • • •

modulation of intestinal flora; prevention of diarrhea; improvement of constipation; lowering fecal enzyme activities; lowering plasma cholesterol level; modulation of immune responses; prevention and treatment of food allergies; prevention of cancer occurrence; adjuvant in Helicobacter pylori treatment.

According to the scientific basis for isolation and defining probiotic bacteria, desirable properties of probiotic strains are as follows (Brassart and Schiffrin, 2000): • • • • • •

human origin; resistance to acid and bile toxicity; adherence to human intestinal cells; colonization of the human gut; antagonism against pathogenic bacteria; production of antimicrobial substances;

© Woodhead Publishing Limited, 2011

Use of probiotics and prebiotics in meat products

405

Table 16.1 Representative commercially available probiotic bacterial strains and their products (from Hoppe et al., 2009) Genus and species Lactobacillus L. acidophilus L. casei L. gasseri L. paracasei ssp. paracasei L. rhamnosus Bifidobacterium B. lactis B. animalis ssp. lactis B. breve B. longum

Strains

Products with probiotic strains

LA-5 NCDO 1748 NCFM SHIROTA OLL2716 (LG21) F19

Fermented milk products, supplements Fermented milk products (Arla Foods) Fermented and nonfermented foods Fermented milk product ‘Yakult’ Yogurt ‘Probio LG21’ Fermented milks ‘Cultura’, cheese

L. casei 431 GG, LGG HN001

Fermented milk products, supplements Various products (e.g., dairy products) Dairy and nondairy products, supplements

HN019

Dairy and nondairy products, supplements Dairy products, infant formula, supplements Fermented milk product ‘Yakult’ Dairy products (e.g. yogurt), supplements

BB-12 STRAIN YAKULT BB536

• immune modulation properties; • history of safe use in humans. Probiotic bacterial strains have been widely utilized for probiotic foods, such as fermented dairy products (Hoppe et al., 2009; Tamime et al., 2005). Examples of commercially available probiotic strains and products utilizing such strains are summarized in Table 16.1. Lactobacillus rhamnosus strain GG, one of most well-used strains of probiotic lactic acid bacteria, has been applied to various dairy products (Fig. 16.1). Products containing the GG strain have been marketed in more than 30 countries under license from a Finnish company (Valio Ltd).

16.3 Probiotics and meat fermentation The possibility of meat products with probiotic bacteria has often been discussed in recent years (Ammor and Mayo, 2007; Ansorena and Astiasarán, 2007; Arihara, 2004, 2006a, 2006b; Arihara and Ohata, 2009; Cocconcelli and Fontana, 2008; De Vuyst et al., 2008; Hammes et al., 2003; KolozynKrajewska and Dolatowski, 2009; Kröckel, 2006; Leroy et al., 2008; Nadal, 2008; Työppönen et al., 2003). Promising target meat products with probiotic bacteria are fermented sausages (dry sausages), since such products are processed without heat treatment and probiotic bacteria can survive in final

© Woodhead Publishing Limited, 2011

406

Processed meats

Fig. 16.1 Examples of dairy products utilizing Lactobacillus rhamnosus GG strain.

Fig. 16.2 Fermented meat spread product ‘Breadton’ utilizing the intestinal Lactobacillus strain (Prima Meat Packers, Ltd., Japan).

products. Although the market for probiotic meat products is still very limited, some probiotic meat products have been marketed in Germany and Japan (Arihara, 2006b). A German producer developed a salami product containing intestinal bacterial strains (Lactobacillus casei, Lactobacillus casei, Bifidobacterium spp.) in 1998. In the same year, a Japanese producer also launched a meat spread product (Fig. 16.2) fermented with intestinal

© Woodhead Publishing Limited, 2011

Use of probiotics and prebiotics in meat products

407

lactobacilli (L. rhamnosus FERM P-15120). L. rhamnosus FERM P-15120 has been screened from the collection of human intestinal lactobacilli (Sameshima et al., 1998, 2002). Since strain FERM P-15120 was resistant to 200 ppm sodium nitrite and 4% sodium chloride and grew at 20 °C, this Lactobacillus strain filled the requirements of the process regulation for non-heat-treated meat products in Japan. In addition, this strain was resistant to gastric acid and bile while passing through the gastrointestinal tracts. This strain also inhibited several undesirable pathogenic bacteria, including Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis, Escherichia coli, Bacillus cereus, Clostridium perfringens and Yersinia enterocolitica, during the meat fermentation. Arihara et al. (1998) have shown that L. gasseri JCM1131 is applicable for meat fermentation as a potentially probiotic strain. L. gasseri, one of the predominant lactobacilli in human intestinal tracts, is used for probiotics and dairy starter cultures. However, since L. gasseri is relatively sensitive to sodium chloride and sodium nitrite (essential compounds for meat products), it is difficult to use this species for conventional fermented meat products, such as dry sausages. Thus, efforts were directed at generating mutants of L. gasseri that resist sodium chloride and sodium nitrite (Arihara and Itoh, 2000). UV irradiation of the strain of L. gasseri JCM1131 generated several mutants that resist these compounds. A mutant strain, 1131-M8, demonstrated satisfactory growth in meat containing 3.3% sodium chloride and 200 ppm sodium nitrite. Although proteins extracted from the cell surface of 1131-M8 were slightly different from those of the original strain, other biochemical characteristics of both strains were indistinguishable. These results suggest that the mutant strain of L. gasseri could be utilized as an effective starter culture to develop probiotic meat products. Erkkilä et al. (2000, 2001a, 2001b) examined the applicability of probiotic strains L. rhamnosus GG, LC-705 and VTT-97800 to dry sausage fermentation. Strains GG and E-97800 were found to be suitable as probiotic starter cultures in fermenting dry sausage. The flavor profiles of sausages with these strains were similar to that with conventional meat starter culture. Since L. rhamnosus strains are popular probiotic bacteria all over the world and have been applied to various products as described above, consumers would accept meat products with L. rhamnosus strains. Also, several studies have demonstrated the possibility of utilizing probiotic strains of lactic acid bacteria and bifidobacteria for meat products (Klingberg and Budde, 2006; Klingberg et al., 2005; Leroy et al., 2006; Pennacchia et al., 2004, 2006; Rebucci et al., 2007; Ruiz-Moyano et al., 2008). Muthukumarasamy and Holley (2006, 2007) studied the effectiveness of a microencapsulation technique for protecting probiotic bacteria during sausage processing. Most of the studies the fermented meat products with probiotic strains have focused on the growth of bacteria in meat products, their sensory properties and inactivation of pathogenic bacteria. Bunte et al. (2000) and

© Woodhead Publishing Limited, 2011

408

Processed meats

Jahreis et al. (2002) carried out remarkable studies on the utilization of probiotic lactobacilli for moist types of fermented sausages. They used healthy volunteers and demonstrated that the ingestion of such fermented meat products with probiotic strains of L. paracasei LTH2579 had some beneficial physiological effects. Daily consumption of such ‘probiotic sausages’ (50 g/day) for several weeks modulated various aspects of host immunity. For example, the levels of CD4 T helper cells were elevated and the phagocytosis index was increased. Although further assessments of the relationship between ingestion of meat products with probiotic bacteria and human health are needed from various viewpoints, a more recent study proved that daily ingestion of raw probiotic sausage effectively modulates the immune system (Rebucci et al., 2007).

16.4 Prebiotics In addition to probiotics, much attention has been paid to prebiotics in the food industry (Brassart and Schiffrin, 2000; Franck, 2008; Roberfroid, 2008). Prebiotics was initially defined as ‘non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon and thus improve the health of the host’ (Gibson and Roberfroid, 1995). Later, this definition was updated as ‘a selectively fermented ingredient that allows specific changes both in the composition and/or activity in the gastrointestinal microflora that confers benefits’ (Gibson et al., 2004). As representative prebiotic substances, oligosaccharides and dietary fibers have been utilized to enhance the growth of probiotic bacteria (Holzapfel and Schillinger, 2002; Roberfroid, 2008; Tanaka and Sako, 2003; Table 16.2). In particular, the ingestion of fructo-oligosaccharides has been shown to stimulate Bifidobacterium in the lower gut (Gibson, 2004). Other prebiotic effects of fructo-oligosaccharides, such as lowering pH in the colon, reducing harmful bacteria, reducing putrefactive substances and improving stool habit, have been demonstrated in human studies (Tanaka and Sako, 2003). Galacto-oligosaccharides are

Table 16.2

Representative prebiotic ingredients

Oligosaccharides

Dietary fibers

Fructo-oligosaccharide Galacto-oligosaccharide Xylo-oligosaccharide Malto-oligosaccharide Isomalto-oligosaccharide Lactosucrose Soy-oligosaccharide

Indigestible dextrin Polydextrose Guar gum Oat powder Soy fiber Citrus powder Apple fiber

© Woodhead Publishing Limited, 2011

Use of probiotics and prebiotics in meat products

409

another group of prebiotics and since they are naturally present in human milk, they have been added to infant formula foods. Alteration of the gut microflora by ingestion of prebiotics has several beneficial effects on health status as follows (Tanaka and Sako, 2003): • • • • • • • • •

suppression of harmful bacteria; reduction of putrefactive substances; reduction of carcinogenetic substances; stimulation of bowel movement; optimization of immune responses; improvement of mineral absorption; activation of colonocytes; acidification of caecal and fecal contents; improvement of lipid metabolism.

Also, desirable attributes of functionally enhanced prebiotics listed by Rastall (2000) are: (1) targeting specific probiotics (Lactobacillus and/or Bifidobacterium), (2) active at low dosage and lack of side effects, (3) persistence through the colon, (4) protection against colon cancer, (5) enhancement the barrier effect against pathogens, and (6) inhibition of adhesion of pathogens. Charalampopulos and Rastall (2009), Gibson and Roberfroid (2008), Lee and Salminen (2009) and Watson and Preedy (2010) provide further information on prebiotics and prebiotic products.

16.5 Meat protein-derived prebiotic peptides In addition to oligosaccharides and dietary fibers, the presence of prebiotic peptides has been reported (Arihara, 2006a; Liepke et al., 2002). Many studies have shown that hydrolyzates of milk proteins exhibited stimulation of the growth of lactic acid bacteria and bifidobacteria (Brody, 2000). However, most of these activities have been estimated to be carbohydrate parts, such as N-acetylglucosamine, of glycosylated peptides (Bezkorovainy et al., 1979; Idota et al., 1994). Later, nonglycosylated peptides derived from proteins were identified. Liepke et al. (2002) first reported nonglycosylated peptides that selectively stimulate the growth of Bifidobacterium. These peptides (5584 and 5801 Da) were isolated from pepsin-treated human milk and identified as lactoferrin fragments. From structural properties, a small peptide named prebiotic lactoferrin-derived peptide I (PRELP-I; Cys-AlaVal-Gly-Cys-Ile-Ala-Leu) was designed. Apart from protein-derived peptides, Etoh et al. (2000) discovered a growth-stimulating peptide (Ala-Thr-Pro-Glu-Lys-Glu-Glu-Pro-Thr-Ala) for Bifidobacterium bifidum from natural rubber serum. Recently, Arihara et al. (2006) found that the hydrolyzate of porcine skeletal muscle proteins enhanced the growth of Bifidobacterium strains. One of the corresponding prebiotic peptides was purified and identified as

© Woodhead Publishing Limited, 2011

410

Processed meats

PH reduction of media after 48 h incubation at 37°C

0.8 Indicator bacteria: B. bifidum JCM1254 Amino acids and peptides: 0.1 mM

0.6

0.4

0.2

0 Glu-Leu- Glu-Leu Leu-Met Met

Glu

Dipeptides

Leu

Met

Glu, Leu, Met

Amino acids

Peptides and amino acids added to skim milk media

Fig. 16.3 Bifidobacterium growth-promoting activities of Glu-Leu-Met and related dipeptides and amino acids.

a tripeptide, (Glu-Leu-Met). Although Glu-Leu-Met showed growth-promoting activity of Bifidobacterium bifidum, neither the dipeptides (GluLeu, Leu-Met) nor amino acids (Glu, Leu, Met), which are parts of the tripeptide, showed growth-promoting activity (Fig. 16.3). Therefore, the sequence of the tripeptide is critical for its growth-promoting activity. Since various peptides can be generated from meat proteins during gastrointestinal digestion, aging, fermentation and enzymatic treatment (Arihara, 2006a; Arihara and Ohata, 2008), prebiotic peptides could be generated in meat and meat products.

16.6

Prebiotics and meat products

Basically, prebiotic ingredients are utilized in foods for their nutritional and physiological advantages. In addition to stimulation of the growth of healthpromoting intestinal bacteria and some other health benefits, they often contribute to organoleptic quality (Franck, 2008). For example, the use of indigestible oligosaccharides as fiber ingredients often improves the taste and flavor of products. In the meat industry, prebiotic ingredients have been used for fat replacement, texture and stability improvement, and fiber functionality. The addition of fibers to meat products has been widely practiced (Jiménez-Colmenero et al., 2006). The addition of fibers improves waterbinding properties, texture and emulsion stability of meat products. Also, antioxidant dietary fibers (e.g., grape fiber) would be effective inhibitors of lipid oxidation for meat products (Sáyago-Ayerdi et al., 2009). Japan is the first country to have formulated a specific regulatory approval process for functional foods (Arihara et al., 2004). The concept of foods for

© Woodhead Publishing Limited, 2011

Use of probiotics and prebiotics in meat products

411

specified health use (FOSHU) was established in 1991. According to the Japanese Ministry of Health and Welfare, FOSHU are foods which, based on knowledge concerning the relationship between foods or food components and health, are expected to have been licensed to bear labeling claiming that a person using them may expect to obtain that health use through the consumption of these foods. As of April 2011, 955 FOSHU products had been approved in Japan. Most FOSHU products utilize functional ingredients to help in the maintenance of a healthy human body, e.g., a pork Vienna-type sausage product containing indigestible dextrin, a watersoluble dietary fiber made from potato starch, which is claimed to have beneficial effects on intestinal disorders (prebiotic effect), has been approved. A reduced-fat smoked sausage formulated with a modified potato starch has been marketed in the United States (Arihara et al., 2004). Such dietary fiber contributes to the improvement of intestinal microflora and the reduction of fat intake.

16.7 Future trends In addition to probiotics and prebiotics, Gibson and Roberfroid (1995) proposed the concept of synbiotics (Fig. 16.4). Synbiotics are foods containing both probiotic bacteria and prebiotic substances to provide a diet in which the growth of the probiotic bacteria is enhanced by the prebiotics, thus promoting the chance of the probiotic bacteria becoming established in the gut and conferring a health benefit (Ziemer and Gibson, 1998). This reasonable combination would result in improvement of intestinal microflora. Gibson (2004) listed future developments expected for probiotics and prebiotics: (1) increased persistence through the colon, (2) anti-adhesive properties, (3) attenuative properties, (4) development of novel prebiotic

Synbiotics Probiotics Lactobacillus Bifidobacterium

Prebiotics Oligosaccharides Dietary fibers Peptides

Intestinal microflora Health maintenance Disease prevention

Fig. 16.4 Concept of probiotics, prebiotics and synbiotics.

© Woodhead Publishing Limited, 2011

412

Processed meats

food ingredients, (5) synbiotics, (6) encapsulation of probiotics with prebiotics, (7) and special level changes. In recent years, effects of synbiotics have been proved by various clinical studies (Bengmark, 2008). Conjugated linoleic acids (CLAs) have attracted considerable attention as nutraceutical compounds found in foods. A CLA is composed of a group of positional and geometric isomers of octadecadienoic acid. Epidemiological studies have suggested that high intakes of high fat dairy foods and CLA may reduce the risk of colorectal cancer (Larsson et al., 2005). In addition to anti-carcinogenic activities, CLA has anti-artheriosclerotic, antioxidative, and immunomodulative activities (Azain, 2003). Also, CLA may play a role in the control of obesity, reduction of the risk of diabetes and modulation of bone metabolism. The effect of probiotic bacteria on the formation of CLA in media and fermented dairy products has been demonstrated (Alonso et al., 2003; Coakley et al., 2003; Kim and Liu, 2002; Sieber et al., 2004; Xu et al., 2005). Such an effect is also expected in fermented meat products. Since CLA is an attractive bioactive compound for designing functional foods, such functional fermented meat products with probiotics and CLA would have a new market. Bioactive peptides, such as antihypertensive and antioxidative peptides, generated from food proteins by proteolysis are considerable functional food components (Gobbeti et al., 2007; Korhonen and Pihlanto, 2007; Mine and Shahidi, 2005). Generation of such bioactive peptides from meat proteins by proteolysis has been studied (Arihara, 2006a; Arihara and Ohata, 2008, 2009; Arihara et al., 2004). In addition, the proteolytic digestion in meat products improves their sensory characteristics (Bruna et al., 2000; Toldrá, 2004). Generation of bioactive peptides in meat products is a possible direction for introducing physiological functions, especially those suitable for fermented meat products. Thus, the combination of probiotics and peptides generated from meat proteins could provide the possibility of developing novel functional fermented meat products. There are still some hurdles in developing and marketing novel probiotic and prebiotic meat products. For example, since consumers in many countries regard meat and meat products as being bad for health, unlike milk and dairy products (Biesalski, 2005), there is still little demand for probiotic and prebiotic meat products. Along with the accumulation of scientific data, consumers should be informed of the clear benefits of novel probiotic, prebiotic and synbiotic meat products for human health. Such efforts would open up a new market in the meat industry. Since food safety is another critical aspect for novel foods such as probiotic and prebiotic meat products, efforts should also be directed to ensure that these products are safe. Although probiotics have been considered as generally recognized as safe (GRAS) food ingredients in most cases and many national governments tend to view probiotics as food rather than drug (Chang, 2009), more scientific evidence would be required for developing new probiotics. However, there is currently lack of standard safety

© Woodhead Publishing Limited, 2011

Use of probiotics and prebiotics in meat products

413

requirements for probiotic organisms (Donohue, 2009). Although FAO/ WHO has a recommended registration process for probiotic product, the FAO/WHO guidelines enabled each member nation to establish its own regulation (Chang, 2009). Since most consumer resistance to genetically modified organisms (GMO), GMO probiotic products are unlikely in the near future. However, basic and clinical research on GMO probiotics has been carried out in many countiries. The safety of prebiotics is also important. The recognition of GRAS status of conventional prebiotic ingredients, such as frucot- and galacto-oligosaccharaides, might be sufficient to guarantee their safety for consumers (Pascal, 2008), but scientific evidence is critical for newly developed prebiotics and prebiotic products. Without proof of product safety, consumers would hesitate to accept novel probiotic and prebiotic products in their diet.

16.8 Sources of further information and advice Further information about probiotics and prebiotics for meat products can be obtained from the following articles. De Vuyst L, Falony G. and Leroy F (2008), ‘Probiotics in fermented sausages’, Meat Sci, 80, 75–78. Franck A (2008), ‘Food applications of prebiotics’, in Gibson R and Roberfroid M B, Handbook of Prebiotics, Boca Raton, CRC Press, 437–448. Kröckel L (2006), ‘Use of probiotic bacteria in meat products’, Fleischwirtschaft, 86, 109–113. Leroy F, Falony G. and De Vuyst L (2008), ‘Latest developments in probiotics’, in Toldrá F, Meat Biotechnology, New York, Springer, 217–229. Nadal E S (2008), ‘Application of prebiotics and probiotics in meat products’, in Fernández-López J and Pérez-Álvarez J A, Technological Strategies for Functional Meat Products Development, Kerala, India, Transworld Research Network, 117–137. Työppönen S, Petäjä E and Mattila-Sandholm T (2003), ‘Bioprotectives and probiotics for dry sausages (review)’, Int J Food Microbiol, 83, 233–244.

16.9 References agrawal r (2005), ‘Probiotics: an emerging food supplement with health benefits’, Food Biotechnol, 19, 227–246. alonso l, cuesta e p and gilliland s e (2003), ‘Production of free linoleic acid by Lactobacillus acidophilus and Lactobacillus casei of human intestinal origin’, J Dairy Sci, 86, 1941–1946. ammor m s and mayo b (2007), ‘Selection criteria for lactic acid bacteria to be used as functional starter cultures in dry sausage production: an update’, Meat Sci, 76, 138–146. ansorena d and astiasarán i (2007), ‘Functional meat products’, in Toldrá F, Handbook of Fermented Meat and Poultry, Hoboken, Wiley-Blackwell, 257–266.

© Woodhead Publishing Limited, 2011

414

Processed meats

arihara k (2004), ‘Functional foods’, in Jensen W K, Devine C and Dikeman M, Encyclopedia of Meat Sciences, Oxford, Elsevier, 492–499. arihara k (2006a), ‘Functional properties of bioactive peptides derived from meat proteins’, in Nollet L M L and Toldrá F, Advanced Technologies for Meat Processing, Boca Raton, CRC Press, 245–274. arihara k (2006b), ‘Strategies for designing novel functional meat products’, Meat Sci, 74, 219–229. arihara k and itoh m (2000), ‘UV-induced Lactobacillus gasseri mutants resisting sodium chloride and sodium nitrite for meat fermentation’, Int J Food Microbiol, 56, 227–230. arihara k and ohata m (2008), ‘Bioactive compounds in meat’, in Toldrá F, Meat Biotechnology, New York, Springer, 231–249. arihara k and ohata m (2009), ‘Functional meat products’, in Toldrá F, Handbook of Meat Processing, Hoboken, Wiley-Blackwell Publishing, 423–442. arihara k, ota h, itoh m, kondo y, sameshima t, yamanaka h, akimoto m, kanai s and miki t (1998), ‘Lactobacillus acidophilus group lactic acid bacteria applied to meat fermentation’, J Food Sci, 63, 544–547. arihara k, nakashima y, ishikawa s and itoh m (2004), ‘Antihypertensive activities generated from porcine skeletal muscle proteins by lactic acid bacteria’, in Abstracts of 50th International Congress of Meat Science and Technology, August 2004, Helsinki, Finland, p. 236. arihara k, ishikawa s and itoh m (2006), ‘Bifidobacterium growth promoting peptides derived from meat proteins’, Japan patent (No. 2006–8738). azain m j (2003), ‘Conjugated linoleic acid and its effects on animal products and health in single-stomached animals’, Proceed Nutr Soc, 62, 319–328. bengmark s (2008), ‘Synbiotics in human medicine’ in Versalovic J and Wilson M, Therapeutic Microbiology: Probiotics and Related Strategies, Washington, DC, ASM Press, 307–321. bezkorovainy a, grohlich d and nichols j h (1979), ‘Isolation of a glycopolypeptide fraction with Lactobacillus bifidum subspecies pennsylvanicus growth-promoting activity from whole human milk casein’, Am J Clin Nutr, 32, 1428–1432. biesalski h-k (2005), ‘Meat as a component of a healthy diet – are there any risks or benefits if meat is avoided in the diet?’, Meat Sci, 70, 509–524. brassart d and schiffrin e j (2000), ‘Pre- and probiotics’, in Schmidl M K and Labuza T P, Essentials of Functional Foods, Gaithersburg, Aspen Publication, 205–216. brody e p (2000), ‘Biological activities of bovine glycomacropeptide’, Br J Nutr, 84, S39-S46. bruna j m, fernandez m, hierro e m, ordonez j a and de la hoz l (2000), ‘Combined use of pronase E and a fungal extract (Penicillium aurantiogriseum) to potentiate the sensory characteristics of dry fermented sausages’, Meat Sci, 54, 135–145. bunte c, hertel c and hammes w p (2000), ‘Monitoring and survival of Lactobacillus paracasei LTH2579 in food and the human intestinal tract’, Syst Appl Microbiol, 23, 260–266. chang w t h (2009), ‘Legal status and regulatory issues’, in Lee Y K and Salminen S, Handbook of Probiotics and Prebiotics, Hoboken, John Wiley & Sons, 95–139. charalampopulos d and rastall r a (2009), in Prebiotics and Probiotics Science and Technology, New York, Springer. coakley m, ross r p, nordgren m, fitzerald g, devery r and stanton c (2003), ‘Conjugated linoleic acid biosynthesis by human-derived Bifidobacterium species’, J Appl Microbiol, 94, 138–145. cocconcelli p s and fontana c (2008), ‘Characteristics and applications of microbial starters in meat fermentation’, in Toldrá F, Meat Biotechnology, New York, Springer, 129–148.

© Woodhead Publishing Limited, 2011

Use of probiotics and prebiotics in meat products

415

de vuyst l, falony g. and leroy f (2008), ‘Probiotics in fermented sausages’, Meat Sci, 80, 75–78. donohue d c (2009), ‘Safety of probiotic organisms’, in Lee Y K and Salminen S, Handbook of Probiotics and Prebiotics, Hoboken, John Wiley & Sons, 75–95. erkkilä s, venäläinen m, hielm s, petäjä e, puolanne e and mattila-sandholm t (2000), ‘Survival of Escherichia coli O157:H7 in dry sausage fermented by probiotic lactic acid bacteria’, J Sci Food Agric, 80, 2101–2104. erkkilä s, suihko m-l, eerola s, petäjä e and mattila-sandholm t (2001a), ‘Dry sausages fermented by Lactobacillus rhamnosus strains’, Int J Food Microbiol, 64, 205–210. erkkilä s, petäjä e, eerola s, lilleberg l, mattila-sandholm t and suihko m-l (2001b), ‘Flavour profiles of dry sausages fermented by selected novel meat starter cultures’, Meat Sci, 58, 111–116. etoh s, asamura k, obu a, sonomoto k and ishizaki a (2000), ‘Purification and identification of a growth-stimulating peptide for Bifidobacterium bifidum from natural rubber serum powder’, Biosci Biotechnol Biochem, 64, 2083–2088. farnworth e r (2008), Handbook of Fermented Functional Foods (2nd edition). Boca Raton, CRC Press. fernández-ginés j m, fernández-lópez j, sayas-barberá e and pérez-álvarez j a (2005), ‘Meat products as functional foods: a review’, J Food Sci, 70, R37-R43. franck a (2008), ‘Food applications of prebiotics’, in Gibson R and Roberfroid M B, Handbook of Prebiotics, Boca Raton, CRC Press, 437–448. gibson g r (2004), ‘From probiotics to prebiotics and a healthy digestive system’, J Food Sci, 69, M141–M143. gibson g r and roberfroid m b (1995), ‘Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics’, J Nutr, 125, 1401–1412. gibson g r and roberfroid m b (2008), Handbook of Prebiotics, Boca Raton, CRC Press. gibson g r, probert h m, van loo j a e, rastall r a and roberfroid m b (2004), ‘Dietary modulation of the human colonic microflora: updating the concept of prebiotics’, Nutr Res Rev, 17, 259–275. gobbetti m, minervini f and rizzello c g (2007), ‘Bioactive peptides in dairy products’, in Hui Y H, Handbook of Food Products Manufacturing – Health, Meat, Milk, Poultry, Seafood, and Vegetables, Hoboken, John Wiley & Sons, 489–517. hammes w p, haller d and gänzle m g (2003), ‘Fermented meat’, in Farnworth E R, Handbook of Fermented Functional Foods, Boca Raton, CRC Press, 251–275. holzapfel w h and schillinger u (2002), ‘Introduction to pre- and probiotics’, Food Res Int, 35, 109–116. hoppe c, larsen c h, fonden r, svensson u, ouwehand a, lahtinen s, kiwaki m, nomoto k, kimura k, eskesen d, larsen c n, saxelin m, kajander k, reid g, bruce a w, nurminen p, korpela r, tsuji h, xiao j-z and salminen s (2009), ‘Commercially available human probiotic microorganisms’, in Lee Y K and Salminen S, Handbook of Probiotics and Prebiotics, Hoboken, John Wiley & Sons, 441–532. idota t, kawakami h and nakajima i (1994), ‘Growth-promoting effects of N-acetylneuraminic acid containing substances on bifidobacteria’, Biosci Biotechnol Biochem, 58, 1720–1722. jahreis g, vogelsang h, kiessling g, schubert r, bunte c and hammes w p (2002), ‘Influence of probiotic sausage (Lactobacillus paracasei) on blood lipids and immunological parameters of healthy volunteers’, Food Res Int, 35, 133–138. jiménez-colmenero f (2007a), ‘Functional foods based on meat products’, in Hui Y H, Handbook of Food Products Manufacturing – Principles, Bakery, Beverages, Cereals, Cheese, Confectionary, Fats, Fruits, and Functional Foods, Hoboken, John Wiley & Sons, 989–1015.

© Woodhead Publishing Limited, 2011

416

Processed meats

jiménez-colmenero f (2007b), ‘Healthier lipid formulation approaches in meatbased functional foods. Technological options for replacement of meat fats by non-meat fats’, Trends Food Sci Technol, 18, 567–578. jiménez-colmenero f, carballo j and cofrades s (2001), ‘Healthier meat and meat products: their role as functional foods’, Meat Sci, 59, 5–13. jiménez-colmenero f, reig m and toldrá f (2006), ‘New approaches for the development of functional meat products’, in Nollet L M L and Toldrá F, Advanced Technologies for Meat Processing, Boca Raton, CRC Press, 275–308. kim y j and liu r h (2002), ‘Increase of conjugated linoleic acid content in milk by fermentation with lactic acid bacteria’, J Food Sci, 67, 1731–1737. klingberg t d and budde b b (2006), ‘The survival and persistence in the human gastrointestinal tract of five potential probiotic lactobacilli consumed as freeze-dried cultures or as probiotic sausage’, Int J Food Microbiol, 109, 157–159. klingberg t d, axelsson l, naterstad k, elsser d and budde b b (2005), ‘Identification of potential probiotic starter cultures for Scandinavian-type fermented sausages’, Int J Food Microbiol, 105, 419–431. kolozyn-krajewska d and dolatowski z j (2009), ‘Probiotics in fermented meat products’, Acta Sci Pol Technol Aliment, 8, 61–74. korhonen h and pihlanto a (2007), ‘Bioactive peptides from food proteins’, in Hui Y H, Handbook of Food Products Manufacturing – Health, Meat, Milk, Poultry, Seafood, and Vegetables, Hoboken, John Wiley & Sons, 5–37. kröckel l (2006), ‘Use of probiotic bacteria in meat products’, Fleischwirtschaft, 86, 109–113. larsson s c, bergkvist l and wolk a (2005), ‘High-fat dairy food and conjugated linoleic acid intakes in relation to colorectal cancer incidence in the Swedish Mammography Cohort’, Am J Clin Nutr, 82, 894–900. lee y k and salminen s (2009), Handbook of Probiotics and Prebiotics, Hoboken, John Wiley & Sons. leroy f, verluyten l and de vuyst l (2006), ‘Functional meat starter cultures for improved sausage fermentation’, Int J Food Microbiol, 106, 270–285. leroy f, falony g and de vuyst l (2008), ‘Latest developments in probiotics’, in Toldrá F, Meat Biotechnology, New York, Springer, 217–229. liepke c, adermann k, raida m, magert h-j, forssman w-g and zucht h-d (2002), ‘Human milk provides peptides highly stimulating the growth of bifidobacteria’, Eur J Biochem, 269, 712–718. mine y and shahidi f (2005), Nutraceutical Proteins and Peptides in Health and Disease, Boca Raton, CRC Press. muthukumarasamy p and holley r a (2006), ‘Microbiological and sensory quality of dry fermented sausages containing alginate-microencapsulated Lactobacillus reuteri’, Int J Food Microbiol, 111, 164–169. muthukumarasamy p and holley r a (2007), ‘Survival of Escherichia coli O157:H7 in dry fermented sausages containing micro-encapsulated probiotic lactic acid bacteria’, Food Microbiol, 24, 82–88. nadal e s (2008), ‘Application of prebiotics and probiotics in meat products’, in Fernández-López J and Pérez-Álvarez J A, Technological Strategies for Functional Meat Products Development, Kerala, India, Transworld Research Network, 117–137. pascal g (2008), ‘Prebiotics and food safety’, in Gibson R and Roberfroid M B, Handbook of Prebiotics, Boca Raton, CRC Press, 449–470. pennacchia c, ercolini d, blaiotta g, pepe o, mauriello g and villani f (2004), ‘Selection of Lactobacillus strains from fermented sausages for their potential use as probiotics’, Meat Sci, 67, 309–317.

© Woodhead Publishing Limited, 2011

Use of probiotics and prebiotics in meat products

417

pennacchia c, vaughan e e and villani f (2006), ‘Potential probiotic Lactobacillus strains from fermented sausages: further investigations on their probiotic properties’, Meat Sci, 73, 90–101. playne m j, bennett l e and smithers g w (2003), ‘Functional dairy foods and ingredients’, Aust J Dairy Technol, 58, 242–263. rastall r (2000), ‘Enhancing the functionality of prebiotics and probiotics’, in Mattila-Sandholm T and Saarela M, Functional Dairy Foods, Boca Raton, CRC Press, 301–315. rebucci r, sangalli l, fava m, bersani c, cantoni c and baldi a (2007), ‘Evaluation of functional aspects in Lactobacillus strains isolated from dry fermented sausages’, J Food Quality, 30, 187–201. roberfroid m b (2008), ‘Prebiotics: concept, definition, criteria, methodologies, and products’, in Gibson G R and Roberfroid M B, Handbook of Prebiotics, Boca Raton, CRC Press, 39–68. ruiz-moyano s, martin a, benito m j, nevado f p and de guia coordo b a m (2008), ‘Screening of lactic acid bacteria and bifidobacteria for potential probiotic use in Iberian dry fermented sausages’, Meat Sci, 80, 715–721. sameshima t, magome c, takeshita k, arihara k, itoh m and kondo y (1998), ‘Effect of intestinal Lactobacillus starter cultures on the behaiviour of Staphylococcus aureus in fermented sausage’, Int J Food Microbiol, 41, 1–7. sameshima t, yamanaka h, akimoto m, kanai s, arihara k, itoh m and kondo y (2002), ‘Screening of intestinal Lactobacillus strains for meat cultures’, Fleischwirtschaft, 82, 101–104. sáyago-ayerdi s g, brenes a and goñi i (2009), ‘Effect of grape antioxidant dietary fiber on the lipid oxidation of raw and cooked chicken hamburgers’, Food Sci Technol, 42, 971–976. sieber r, collomb m, aeschlimann a, jelen p and eyer h (2004), ‘Impact of microbial cultures on conjugated linoleic acid in dairy products – a review’, Int Dairy J, 14, 1–15. sloan a e (2008), ‘The top 10 functional food trends’, Food Technol, 62(4), 25–44. stanton c, desmond c, coakley m, collins j k, fitzgerald g and ross p (2003), ‘Challenges facing development of probiotic-containing functional foods’, in Farnworth E R, Handbook of Fermented Functional Foods, Boca Raton, CRC Press, 27–58. tamime a y, saarela m, sondergaard a k, mistry v v and shah n p (2005), ‘Production and maintenance of viability of probiotic micro-organisms in dairy products’, in Tamime A Y, Probiotic Dairy Products, Oxford, Blackwell Publishing, 39–72. tanaka r and sako t (2003), ‘Prebiotics’, in Roginski H, Encyclopedia of Dairy Sciences, London, Academic Press, 2256–2276. toldrá f (2004), ‘Dry’, in Devine C, Dikeman M and Jensen W K, Encyclopedia of Meat Sciences, Oxford, Elsevier, 360–365. työppönen s, petäjä e and mattila-sandholm t (2003), ‘Bioprotectives and probiotics for dry sausages (review)’, Int J Food Microbiol, 83, 233–244. watson r and preedy v r (2010), Bioactive Foods in Promoting Health: Probiotics and Prebiotics, London, Academic Press. xu s, boylston t d and glatz b a (2005), ‘Conjugated linoleic acid content and organoleptic attributes of fermented milk products produced with probiotic bacteria’, J Agric Food Chem, 53, 9064–9072. ziemer c j and gibson g r (1998), ‘An overview of probiotics, prebiotics and synbiotics in the functional food concept: perspectives and future strategies’, Int Dairy J, 8, 473–479.

© Woodhead Publishing Limited, 2011

17 Marinating and enhancement of the nutritional content of processed meat products S. M. Yusop, University College Cork, Ireland and National University of Malaysia, Malaysia and M. G. O’Sullivan and J. P. Kerry, University College Cork, Ireland

Abstract: Marinade technology has been used in the meat industry for several decades. In domestic meat cookery and the food service industry, the use of marinades has been employed for an even longer period. With a special emphasis on marinating of poultry meat products, this chapter will review the background to marinating of muscle foods, mode of marinade action, ingredient utilisation in marinade technologies used to deliver marinades and finally the significance of sensory evaluation and multivariate analysis in determining quality of marinated products. Key words: marinating, technology, muscle foods, ingredients, sensory evaluation.

17.1 Introduction The role and perception of marinades have evolved from flavouring and tenderizing to enhancing yield and quality of meats. The industrial marinating of broiler chickens is a well-established commercial process which has transferred seamlessly for use with other fowl applications, including; spent fowl and Cornish game hens, and for other poultry species, including turkeys and ducks (Smith & Acton, 2001). However, in the pork industry, and to a lesser extent, the beef industry, marinating, particularly through injection, has made considerable technological advances only in the past few years (Xiong, 2005). The demand for marinated chicken in Europe is continually growing due to the increase in consumer, retailer and catering demand for furtherprocessed, ready-to-eat, convenience foods (Yusop et al., 2009a, b). It is believed that the growth of the poultry industry, which is attributed to

© Woodhead Publishing Limited, 2011

422

Processed meats

product versatility, sensory quality and absence of adverse religious or cultural aspect, has led to the continued development of additional value-added products, including marinated poultry meats (Mandava & Hoogenkamp, 1999). According to Smith and Acton (2001), market forms of marinated poultry include whole birds, processed parts, boneless meat and chopped and formed items. Most of the products sold in the raw, nonmarinated state will be marinated later by the retailer or by the consumer in the home prior to sale or consumption, respectively. In addition, food sectors such as frozen ready-meals and cooking sauces, particularly those possessing ethnic flavours such as Indian and Chinese (Fig. 17.1), appear to be reaching maturity in developed markets like the UK, while growth levels are expected to further increase in European countries, particularly in Ireland, Spain and parts of the Benelux countries (Leatherhead Food International, 2007). There has been a recent increase in the range of commercially available marinade products which include ready-to-use forms (e.g. dry rubs, glazes and single shot marinades) or those requiring simple preparation (e.g. powder and liquid marinade). The emergence of a diverse range of marinades in the market, allows consumers to complement their culinary skills at home, as well as making mealtimes more interesting. In the food industry, a variety of marinating systems including multineedle injection, massaging, tumbling or vacuum tumbling, are utilised to accelerate marinade absorption into meat. Each marinade system has distinct advantages and disadvantages, and should be chosen according to the needs of the manufacturer and the intended use of end products. With the increase in demand in marinated poultry products, extensive research has been conducted which pertains to the quality of meat that commercial marinating produces has been conducted to date (Barbanti & Pasquini,

Fig. 17.1 Some of the commercially available Indian and Chinese marinades and sauces in the Irish marketplace.

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

423

2005; Cheng & Ockerman, 2003; Hyk, 2001; Woods et al., 1997; Xargayo et al., 2001).

17.2 Background and terminology associated with marinating The scientific literature includes many definitions for a marinade and sometimes these can appear to be conflicting. Furthermore, since marinades are often culturally and regionally unique, there are broad definitions used to define a marinade. The word ‘marinate’ probably derives from the Latin word ‘marinus’ adopted into the Italian, Spanish and French languages, and generally referring to soaking/pickling in salt brine (Bjorkroth, 2005). Table 17.1 displays some of the most recently published journal articles related to marinating of muscle-based products. The word ‘marine’ refers to the seawater used to preserve food before the advent of refrigeration. Historically, marinating entailed soaking meat, usually from 1 to 24 hours, in a solution containing salt and/or acids with added sugar, spices or oils. It was likely to have originated from the process of preserving and brining, when Vikings and other sailors who spent long periods at sea used these methods to preserve their food supply and stave off starvation (Anon, 2003). At present, marinating is commonly employed by the restaurant industry and fast-food outlets as well as by consumers at home, to incorporate intended particular flavours or colours in poultry and meat products. On a bigger scale, the food industry marinates with salt and phosphate solutions after chilling to increase yield and improve the quality of meat. More specifically, the term ‘marinade’ is primarily referred to a mixture of non-meat ingredients, in a form of liquid solution or powder that is applied to uncooked food, particularly meat, to enrich its flavour or to tenderise it. Marinating has been recognised as a traditional technique to enhance meat quality, by tenderising and improving the flavour of meat (Woods & Church, 1999). According to Suderman (1993), marinating is the process of applying an aqueous solution composed of ingredients such as salt, phosphates, acids, tenderisers, sugar, seasoning, and flavourings to meat products. Smith and Acton (2001) defined marinating as the process of soaking muscle-based materials in vinegar, oils or both, in combination with spices, to improve the flavour of the product, extend shelf-life and/or mask off-flavours. From the USDA’s Food Safety and Inspection Service (FSIS) perspective, the word ‘fresh’ cannot be used to describe this type of product. To be labelled as ‘marinated’, a product must use a marinade that is a mixture in which food is either soaked, massaged, tumbled or injected in order to improve taste, tenderness or other sensory attributes, such as colour or juiciness. The term ‘brine’ and its verb brining are often misused with ‘marinade’ and ‘marinating’. The differences lie in the functional properties contributed by the ingredients, in which marinades principally contribute more

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Broiler

Chicken

Chicken fillet

Organic acids (tartaric, acetic, lactic, malic, and citric acids) and acidic food ingredients (vinegar, lemon juice, pomegranate syrup, and soy sauce)

Chinese-style marinade solution, with the ratio of 20 : 80 dry mix to distilled water, citric acid

Birk et al. (2010)

Yusop et al. (2010)

Turkey

Salt, phosphate

Water, salt and phosphate

Bowker et al. (2010)

Meat

Gorsuch & Alvarado (2010)

Marinade composition

Authors Turkey breasts were HDP-induced (hydrodynamic pressure processing), then vacuum-tumbled with marinade for 30 min. Samples were vacuumtumbled in various phosphate-based marinade pH condition C. jejuni strains were exposed to different organic acids (tartaric, acetic, lactic, malic, and citric acids) and food marinating ingredients at 4 °C in broth and on chicken meat Fresh samples were immersed in specific acidic marinating pH and time in plastic containers, then dry cooked at 150 °C

Marinade approach

Samples of higher acidic pH (3.8, 4.0 and 4.2) and longer marinating times (T120–180) were more highly correlated to overall acceptability along with the most sensory quality attributes. Surface colour is also considered as contributing to a greater degree to product’s acceptability compared with colour penetration.

Phosphate marinating can be used to marinate pale meat without altering flavor, increasing the development of oxidation, or reducing shelf-life. Acidic food ingredients reduced counts of C. jejuni by at least 0.8 log units on meat medallions. It resulted in a reduction of approximately 1.2 log units after 3 days of storage with positive flavour and texture when applied to meat.

HDP enhances brine absorption, increases processing yield, and improves texture characteristics in marinated turkey breasts.

Overall findings

Table 17.1 Some examples of the most recently published journal articles outlining current research focus pertaining to the marinating of muscle-based products

© Woodhead Publishing Limited, 2011

Citric acid buffer, acetic acid buffer

Water solution containing salt, glucose, antimicrobials (thymol, cinnamaldehyde, allyl isothiocyanate, citric acid, ascorbic acid, rosemary extract, grapefruit seed extract)

Schirmer & Langsrud (2010b)

Pork

Pork

Beef

Diluted hibiscus extract, water, homogenising sunflower oil, emulsifier

Gibis & Weiss (2010)

Schirmer & Langsrud (2010a)

Meat

Marinade composition

Authors Frozen samples were coated with marinades and covered on by tin foil, then broiled for 160 s at 72 °C and a surface temperature of <190 °C at the end of the frying process Fresh pork fillet was packed with a small amount of 100% CO2 (initial gas/ product ratio 0.2/1.0) and a brine solution containing citric acid, acetic acid or a combination of both Marinade was added directly to vacuum bag and distributed evenly on the meat. Samples were vacuum-packed and stored at 4 °C

Marinade approach

Antimicrobial concentrations of up to 10 times the minimum inhibitory concentration values showed no effect on total bacterial growth in vacuum packed pork, implying that although most antimicrobials inhibited the growth of spoilage bacteria in vitro, results from the microplate assay could not be transferred to the meat system. The use of natural antimicrobials in meat products is limited and that bacterial quality and shelf-life was not enhanced under the chosen conditions.

Combinations of citric acid, acetic acid and CO2 inhibited bacterial growth in marinated pork meat. CO2 dissolved in the product, avoiding problems like the increased package volume of traditional MAP compared with vacuum packaging.

Pretreatment by marinating meats with hibiscus extracts may inhibit formation of heterocyclic amines during frying without negatively impacting sensory characteristics.

Overall findings

© Woodhead Publishing Limited, 2011

Yusop et al. (2009b)

Yusop et al. (2009a)

Samples were injected with marinades at 5% (ENZ) and 15% (ME, ME +NZ) from original mass, and then were blade tenderised before grilling

Samples were evenly applied with the marinade, glaze or paste samples according to the manufacturer’s guidelines Samples were evenly applied with the marinade according to the manufacturer’s guidelines

Beef semitendinosus (ST) muscle

Chicken

Chicken

The Malaysian and European assessor groups had a similar attitude towards Indian-style marinated chicken. Aroma-flavour related attributes and the amount of fat were considered important in determining the overall acceptability. The European and Chinese assessor groups perceived samples very differently. The Chinese did not consider the Chinese marinades samples available in Irish marketplace as authentic in flavour.

Injection of phosphate/sodium chloride solution to achieve 15% extension in beef ST was a potential way of improving tenderness and juiciness of ST muscle. Injection of porcine pancreatin tended to reduce WBSF and improve overall tenderness without decreasing flavour and juiciness.

Injection of the chuck muscles with studied ingredients and water represents an effective method of improving their tenderness and in most cases also increasing cook yield.

Muscle sections were injected with enhancement solutions at an injection rate of 110%

Bovine m. supraspinatus and m. triceps brachii caput longum

Sodium lactate (NaLac), potassium lactate (KLac), carrageenan, whey protein concentrate (WPC), yeast extract or fungal proteinases alone or in combination with NaCl Water-based injection solutions consist of an enzyme treatment (ENZ; liquid porcine pancreatin) a moisture enhanced treatment (ME; sodium chloride and sodium trypolyphosphates) and a combined moisture enhanced with enzyme treatment (ME + ENZ) Commercially available Indian marinades/sauces containing water, yoghurt, double cream, onion, concentrated tomato puree, spices, etc. Commercially available Chinese marinades/sauces containing water, sugar, vinegar, soy sauce, paprika extract, vegetable oil, etc.

Walsh et al. (2010)

Pietrasik et al. (2010)

Overall findings

Marinade approach

Meat

Marinade composition

Continued

Authors

Table 17.1

Marinating and enhancement of nutritional content

427

towards flavour enhancement, whereas brines contribute more towards tenderisation (Aidells, 2006). Furthermore, marinating often has little influence on meat tenderness. This applies especially in the case of commercial marinades, which play a role in improving palatability by enhancing or complementing the flavour of the meat with the presence of flavouring agents (Gault, 1991; Rao et al., 1989). Both marinades and brines also contain similar ingredients, typically water, salt, phosphates and flavouring agents; however, brines contain minimal flavour. The origins of the word ‘marinade’ itself allude to the use of brine (aqua marina) in the pickling process, which led to the technique of adding flavour by immersion in liquid. Curing, a process similar to marinating, is used as a means of preserving meat. Although curing brines were developed separately from the early culinary approaches of marinade development, they share a similarity in that they are principally based on delivering their functions through liquid incorporation into the meat tissue. Preservation via curing processes is achieved through reduction of water activity by means of salt addition and drying, delivering high quality products (Hayes et al., 2007). This is carried out simply by including nitrite in the ‘curing brine’, together with salt, sugar, curing accelerators and seasonings. Whole carcasses or whole boneless meat pieces for products such as whole turkeys or chickens, whole boneless breasts may be cured by using delivering techniques similar to marinating, including soaking, vacuum tumbling and injection.

17.3 Marinade action: absorption and retention in a marinating system The water-holding capacity (WHC) of fresh meat, one of the most important characteristics in determining meat quality, can be improved via marinating. The inherent water in fresh meat is 75%, but without proper treatment, a huge amount of water could be lost during handling, storage and particularly when cooking. Marinating is a complex process which involves a series of stages, all of which are still not clearly elucidated. Yet, to aid water retention in meat, the marinade has first to be successfully delivered into the meat. The mechanism of marinade absorption/retention and WHC of meat is centred in the proteins and structures that bind and entrap water; specifically that of salt-solubilised myofibrillar proteins, including actin, myosin and the actomyosin complexes (Alvarado & McKee, 2007; Smith & Acton, 2001). In contrast, sarcoplasmic proteins are soluble in water or in low ionic strength solutions; they thereby have a poor WHC and play only a minor role in meat protein functionality (Smith, 2001). In the case of poultry meat, the long thin parallel myofibres, or muscle cells, each surrounded by connective tissue (principally collagen), provide some opportunity for the excess fluid added from marinating to be absorbed and held within the tissue (Smith & Acton, 2001). More specifically, within the

© Woodhead Publishing Limited, 2011

428

Processed meats

muscle cell, water is found within the myofibrils, between the myofibrils themselves and between the myofibrils and the cell membrane (sarcolemma), between muscle cells and between muscle bundles (groups of muscle cells) (Offer & Cousins, 1992). Thus, anything which affects the spacing between the thick and thin filaments of myofibrils will affect marinade absorption/retention. In a phosphate-free marinade system, salt is the principal ingredient in myofibril solubilisation. Tumbling, massaging or mixing in the presence of salt is used to disrupt the muscle cells, disintegrate the muscle fibres, and extract the myofibrillar proteins, with most of the changes occurring on the surface of the meat pieces (Smith, 2001; Yusop et al., 2010). Marinades, which usually contain salt as well as other ingredients such as sugar, flavour and colouring agents, diffuse into the meat surface to the interior of the meat due to the gradient formed from the higher concentration of marinade to the lower concentration of fluid in the interior of the meat. Owing to the ionic characteristics of salt, the number of charged sites increases, thus partially unfolding or opening the space among the protein molecules to allow water-binding sites to become available. This forces marinades to penetrate the sarcolemma, thus causing the myofibrils to swell and later resulting in the extraction and solubilisation of myofibrillar proteins. Consequently, this solubilised protein mix with sarcoplasmic fluid, which is water soluble, forms an increased protein concentration that will produce a protein matrix to trap water. This also contributes to the formation of a viscous coating on the product surface that acts as a shield to prevent entrapped marinade/water from leaking out from the interior of meat, especially during the holding period. Occasionally, the increased protein concentration elevates the meat’s interior osmotic pressure within the interior of the meat, causing water/ marinade from the exterior to move into the meat rather than vice versa. This results in the absorption of the water-soluble flavour and colour from the marinade, and the consequent penetration into the meat (Fig. 17.2(a)). At this point and depending on production factors such as; the delivery method, process conditions and the final marinade content (%) in the products, meat usually increases its weight from 6 to 10%. The phenomenon of marinade absorption and retention continues during cooking, but the ability to retain water is usually lower in denatured protein owing to fewer spaces being available in the denatured protein to entrap water (Fig. 17.2(b)). The highly concentrated protein networks undergo gelling formation upon heating to form a gel matrix that entraps water. This contributes to the retention of the marinade in meat; however, the product continues to lose a proportion of the added marinade/water as a consequence of heating. However, this loss is counter-balanced by the marinade absorbed earlier during the marinating holding time. In addition, the gel matrices also act as a barrier from direct contact to heat during cooking, resulted in a more tender, flavourful and moist-cooked meat.

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

429

(a) Marinade

Viscous coating from high concentration sarcoplasmic fluid

Cl– [ ] Na+

Flavour, colour penetration vis osmosis Diffusion

H2O prevented from leaking out

Myofibrillar solubilised

Raw meat

(b) Gel formed during cooking Surface colour development Unbound H2O evaporated

Heat transfer Marinade, H2O retained

Tenderness increased

Moisture, cooking loss minimised

Flavour and colour retained

Denatured meat

Fig. 17.2 Phenomenon of marinade absorption and retention during (a) marinating and (b) cooking.

Without sufficient myofibril solubilisation, sarcoplasmic fluid will be low in concentration through dilution by marinades; causing proteins to aggregate and precipitate, thereby releasing free water. Thus, myofibril solubilisation is vital in the marinating mechanism due to its role in increasing protein concentration in the sarcoplasmic fluid and consequently permitting gel formation on heating.

17.4 Functional ingredients of marinating Marinating is an ingredient delivery process used to improve flavour, texture and juiciness of meat. The functionality of most marinades is directly dependent on the ingredients used in the solution; therefore they also directly influence the yield and the overall quality of the marinated products. According to Toledo (2007), marinade ingredients can be classified into two categories, based on their functionality. The first category consists of those ingredients that affect the water-binding or textural properties, and

© Woodhead Publishing Limited, 2011

430

Processed meats

condition the meat to bind water via ionic strength and pH. Ingredients such as water, salt, phosphates, organic acids, hydrocolloids, protein isolates, curing aids and enzymes fall into this category. The second category consists of those ingredients which affect the consumer appeal and the eating quality of the marinated chicken. These secondary ingredients include; herbs and spices, flavour extracts and sweeteners.

17.4.1 Salt The most common and important ingredients of marinades are salt and alkaline phosphates. These ingredients enhance meat structure by increasing meat pH, ionic strength, moisture content and tenderness; by binding proteins; and by dissociation of actomyosin (Young et al., 1992; Suderman, 1993). Generally, NaCl is used as a salt component to improve the flavour and tenderness of the meat. Sodium chloride has been observed to improve the binding properties of poultry meat by increasing the solubility of the myofibrillar proteins (Babji et al., 1982). The amount of salt to be added in the marinade is determined according to palatability of the finished product, since it has an adverse effect on taste after some point (Alvarado & McKee, 2007; Puolanne & Ruusunen, 2009). In meat formulations, about 1.5 to 2% salt is typically used to allow for the extraction and solubilisation of the myofibrillar proteins, making the salt content in a typical marinade range from about 4 to 10%.

17.4.2 Phosphates Phosphates often act synergistically with salt to increase WHC and cooking yield (Xiong & Kupski, 1999b). Together, they increase WHC in fresh and cured meat products by increasing the ionic strength, which frees negatively charged sites on meat proteins, so that the proteins can bind more water. Sodium tripolyphosphates (STPP) are the most commonly used phosphates in marinades because of their economy and solubility (Alvarado & McKee, 2007). Polyphosphates have a noticeable effect on the characteristics of poultry products. This includes the beneficial effects of alkaline phosphates in reducing cooking losses (Xiong & Kupski, 1999b; Zheng et al., 1999), improving tenderness (Lyon et al., 1998), colour quality (Kim & Marshall, 2000) and consumer acceptability (Capita et al., 2000; Grey et al., 1978) of the meat products, which normally occur at a much higher pH and within the range of 7.0–9.8. However, despite their extensive application in improving meat quality, several countries have banned their use in raw meat production as well as imported phosphate-treated meat products. Polyphosphate addition is currently perceived as a negative and unpopular among consumers because of the clean labelling issue. The omission on food labels of chemically descriptive words, such as in the list of ‘declared ingredients’ and ‘non-meat binders’ is one of the recent trends in the food industry.

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

431

Therefore, meat processors are working hard to have an ‘all-natural’ claim on product labels by removing ingredients that may not be considered ‘consumer friendly’ and substituting ingredients that can be considered natural. From another perspective, excess phosphate addition may also cause undesirable characteristics to meat; such as soapy, metallic flavour, rubbery texture, and poor colour, particularly in mildly -spiced meat products (Lynn, 2004). Thus, there is a vital need for alternative meat marinades which do not rely on polyphosphates and which are capable of enhancing yield, texture and overall appearance of meat products.

17.4.3 Water Another crucial component, and often overlooked as a functional ingredient in meat marinating, is water. While water is inherently a major component of raw meat, it is typically lost during cooking due to evaporation (Fig. 17.2). Thus, water is added during marinating, to compensate for the expected product weight loss, thereby improving product yield and enhancing product juiciness (Xiong, 2005). Water, which is often called the ‘universal solvent’, also serves as a carrier and a dispersing agent for salt, phosphates, sugar, and water-soluble flavour and colour ingredients in the marinade (Canning, 2004). The solvent property of added water in marinades, which is usually added at approximately 10–20% of the meat weight, chiefly plays an important role in meat protein extraction and cooked product textural properties (Tarté & Amundson, 2006). This is due to the formation of high concentrations of sarcoplasmic fluid which later produces a gel on the surface substrate when heated, entrapping moisture and targeted flavour in the meat thereby resulting in a juicier, more flavourful and tender product. Without added water, it would be very difficult to achieve a uniform distribution of marinade ingredients into meat, particularly in an industrial marinating context, where tumbling and injecting of marinades into meat is practised. Canning (2004) reported that aspects such as water pH and hardness were crucial in managing water quality for industrial marinating. Toledo (2001) reported that marinade retention and process yields decrease as water hardness increases, through as little as 50 parts per million (ppm) calcium carbonate (CaCO3). Variations in pH and contaminants, such as nitrates, contribute to product defects such as pinking (Canning, 2004). Therefore, it is recommended that water for industrial marinating is purified so as to remove all contaminants and maximise marinade functionality.

17.4.4 Organic acids The use of organic acids for acidic marinating has been a very popular traditional culinary technique used to enhance the flavour and tenderness of meat prior to cooking. An acidic solution for home and food service marinating includes vinegar, wine, beer, fruit juice, pineapple, buttermilk,

© Woodhead Publishing Limited, 2011

432

Processed meats

citrus juice, Italian dressing, salsa and yogurt (Lewis & Purslow, 1991; Stanton & Light, 1990). Most ethnic marinades, such as Chinese Szechuan and Italian, incorporate acids as part of the sauce ingredients. The incorporation of these substances (e.g. acetic, lactic and citric acid) and pH reducing adjuncts (e.g. soy sauce) are often employed in the acidic marinating process as part of a mix of flavour enhancers, as opposed to preservative adjuncts per se. Acidic marinades uniquely possess several functioning actions, including weakening of physical structures due to swelling of the meat, increased proteolysis by cathepsins and increased conversion of collagen to gelatin at low pH during cooking. These actions decrease the mechanical resistance of meat, including meat cuts containing a high connective tissue content (Gault, 1985; Offer & Knight, 1988; Wenham & Locker, 1976). Previous studies on acidic marinating have been carried out with the primary focus of the research being on its tenderising effect on high connective tissue content cuts, particularly beef (Berge et al., 2001; Burke & Monahan, 2003; Gault, 1984, 1985, 1991; Lewis & Purslow, 1991; Oreskovich et al., 1992; Stanton & Light, 1990). The use of acidic marinades has been recently reported to produce a higher marinade uptake for chicken samples which were immersed in a marinade possessing a pH range of 3.8 to 4.2 than that of a lower pH range of 3.0 to 3.8 (Yusop et al., 2010). These authors also suggest that water/marinade penetration into muscle tissue during low pH marinating, particularly by immersing/soaking, is more a pH-dependent rather than a time-dependent process. Marinades must overcome physical barriers in muscle, e.g. sarcolemma and actomyosin cross-linkages, in order to diffuse into the fibres and myofibril matrices (Xiong & Kupski, 1999a); and consequently, this process is highly dependent on the environment provided by the marinade. A detrimental texture effect of acidic marinating may also produce a mushy and soft meat texture as well as a less palatable meat product; however, this can be resolved by using a shorter marinating time, i.e. 120 to 180 min exposure of meat to acidic marinades (Yusop et al., 2010, Fig. 17.3).

17.4.5 Binders Water-binders such as hydrocolloids, gelatins, soy and milk proteins as well as modified food starch can be used in marinade formulation. Marinated products with a high moisture or cooking loss often correlate with a meat product possessing a poorer flavour and texture. The incorporation of binders into marinades has become a relatively new topic of interest, primarily because of their potential to replace phosphate as a marinade functional ingredient. Hydrocolloids (polysaccharide gums and starches) are added into marinade formulations due to their exceptional inherent water-binding and texture-modifying abilities, by suspending other particulates in marinades (Shand et al., 1993). Bater et al. (1993) studied turkey breasts injected with

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

0.6

433

T120

0.4 T180

pH3.8

PC2

0.2

0.0

–0.2

Colour a* pH3.2 Overall acceptability Flavour liking Sweetness Juiciness Maximum force pH3.0 Cook loss Sourness Expressible moisture Aroma liking pH3.6 Dark pink Marinade uptake Colour penetration pH4.0 Moisture content pH3.4Toughness Meat pH Colour b* pH4.2 T30

–0.4

Colour L* T60

–0.6 –0.6

–0.4

–0.2

0.0

0.2

0.4

0.6

PC1

Fig. 17.3 Overview of the variation found in the data from the ANOVA-Partial Least Squares Regression (APLSR) correlation loadings plot for the individual effect of marinating time and marinade pH. Shown are the loadings for the X- and Y-variables for PC1 (Principal Component 1) versus PC2 (Principal Component 2). ▲ = Instrumental and sensory descriptor, ■ = Time/pH treatment. The ellipse highlights samples and attributes which are highly correlated to each other (adapted from Yusop et al., 2010).

solutions containing salt and phosphate with carrageenan and or starch and found that their incorporation improved yields and visual appearance compared with salt phosphate-only treated turkey breast. The effect of injecting pectin on the marinating performance of injected-chicken breast has also been studied (Detienne et al., 2000; Zheng et al., 1999). These authors observed that the injection of pectin resulted in an intermediate marinade pickup and cook yield but produced higher shear values than phosphateinjected samples. Hydrolysed soy proteins, which have a high solubility in water, were also injected into meat to enhance product flavour, juiciness, and cooking yield (Xiong, 2005). Soy protein in marinated poultry is generally superior when compared with starch and hydrocolloid ingredients. Xiong (2005) reported that the soluble myofibrillar proteins extracted by the marinade containing hydrolysed soy proteins produced a viscoelastic gel matrix which then contributed to the entrapment of water in cooked meats. Feng and Xiong (2002, 2003) suggested that the synergistic interactions of soy protein with muscle proteins produced a gel matrix capable of immobilising extraneous water, supported by the strong hydrophilicity of

© Woodhead Publishing Limited, 2011

434

Processed meats

soy peptides, thereby increasing its superior WHC (Adler-Nissen & Olsen, 1979).

17.4.6 Spices and flavourings Ethnic marinades and ethnic flavour-marinated meat products are very popular today due to the increased demand for such products by consumers who are more adventurous, demand products possessing more authenticity and desire a more flavourful experience when eating meat (Yusop et al., 2009a,b, 2010). In Europe, the Chinese/Oriental flavours significantly lead other market segments with a 42% share in 2006, ahead of Mexican/American (27%) and Indian (25%) flavours (Leatherhead Food International, 2007). Spices and flavourings are incorporated in a marinade system to provide a variety of flavours and aromas to meat with the aim of enhancing the eating quality and appearance of the final product. Some commonly used spices in marinades include basil, cinnamon, cloves, fennel seed, garlic, onion, paprika, rosemary, thyme and turmeric. Spices such as paprika, turmeric, and saffron can be used as colours in foods and are referred to as spices and colourings. According to Harisa and Takimasa (1998), these guidelines can be used for using when selecting spices as colouring ingredients: • Because there is a water-soluble component or an oil-soluble component in each spice, the appropriate types have to be chosen to suit the cooking purpose. • Because some spice colour components change their colour tones due to the pH of the solution, the pH of the solution in which spices are dissolved can be changed. • Some spice colour components of spice can be stabilised when used with metals (e.g. aluminium stabilises the bright yellow colour of flavonoid). • Because most of the colour components of the spice will change their colour tone upon heating, heating conditions must be carefully controlled. • Spices with colour components that do not seep out of the spices during cooking can be used directly when cooking. Spice extracts and oleoresins are much easier to control than the whole or ground spice for quality purposes, particularly because they possess a more consistent flavour and colour intensity, thereby providing the same yield of aroma and flavour of the named spice (Coggins, 2001). Studies focusing on flavour incorporation into meat via marinating process are scant, despite its extensive application in home cooking, the food service sector as well as in the meat industry. The use of spice extracts as an alternative to crude spices and natural colouring agents for meat is known (Aguirrezábal et al., 2000; Gómez et al., 2008). Spice extracts are widely used in the industry as they are easily soluble and are compatible with injection marinating systems as

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

435

they do not clog the injection needles (Carlos & Harrison, 1999; Ferrell, 1990). The increasing use of paprika as a food colour, as well as flavouring agent, to meat products has also been observed (Bloukas et al., 1999; Gómez et al., 2008; Yusop et al., 2011b). Yusop et al. (2011b) reported that paprika oleoresin produced a good quality surface orange-red colour and colour penetration without the need of a prolonged marinating holding time. Aguirrezábal et al. (2000), in their study on the effect of paprika on rancidity in dry sausages, reported that paprika possessed antioxidant properties and was able to inhibit the pro-oxidant effect of salt.

17.5 Methods of marinade delivery To deliver flavour as well as improve moisture retention, bind and improve the texture of meat products in marinated meats, it is critical that marinating technique and delivery are carefully selected. Approaches include dry and paste marinades, which are associated with home and the culinary sector, as well as immersion, injection, tumbling and massaging, which are more associated to industrial marinating, are some of the processes applied in meat marinating.

17.5.1 Dry marinades Also known as ‘rub’, or ‘spice rub’, a dry marinade is fairly simple and straightforward technique compared with other methods. It combines herbs, spices, salt and sometimes sugar in a mixture that is rubbed or sprinkled onto muscle-based products that have been lightly brushed with vegetable oil to make the mixture adhere to the substrate. In order to assist marinade penetration into the meat in some cases, the surfaces of the product in question can be scored using a knife so that the resulting deep channels allow the marinade to occupy the free spaces created, thereby entrapping the marinade. It is the most convenient form of marinade, as dry marinade remains on the food during cooking. Through osmosis, the salt in the dry marinade draws moisture from the surface of the meat. The dry surface, combined with the savoury rub, create a crust that adds flavour, texture and visual appeal to the cooked meat. Sugar contributes to osmosis and so to the creation of the crust as well as caramelisation and flavour enhancement. The substrate can be stored in the refrigerator for a day or two or can be cooked immediately, but the longer it is exposed to the spices and/or herbs, the more they will permeate. It is believed that dry marinades use the capillary action of salt to break down the proteins; it also helps to infuse flavours by drawing them in. Dry rubs are a better approach for extremely tender cuts such as fillets, since too much time in an acidic marinade can make the readily tender meats mushy and unpalatable. Dry rubs are recommended over marinating for large pieces of meat such as turkeys, briskets and large

© Woodhead Publishing Limited, 2011

436

Processed meats

game because a dry rub will not sear or burn on the grill the way marinades can during the long, slow cooking required for these large cuts.

17.5.2 Paste marinades Paste marinades are variations of dry marinades or rubs, with some form of liquid added. They are puréed with spices and sometimes oil or other liquids. The paste ingredient can be varied from mustard, oil, butter, fruit juice and peel to rehydrated dried chillies, garlic, onions, ginger and/or fresh herbs such as basil or cilantro. Paste marinade is spread on a cut of meat, which is left to marinate for a few hours to overnight in the refrigerator before cooking. Most of the pastes adhere to the meat to form a flavour crust to grilled or roasted meats or poultry. A paste marinade is good at producing a marinated product with a more intense flavour.

17.5.3 Immersion processing Immersion, also called soaking or still marinating, is another simple approach to marinating. Immersion is often practised in home cooking and by the food service sector as it is the most economical marinating method and does not require sophisticated equipment. This consists of immersing the substrate in a liquid marinade and allowing penetration of the meat through diffusion over time, i.e. 8–12 h for chicken breast meat (Yusop et al., 2010). The major drawback to the immersion method is the lower and slower marinade uptake rate, as it requires long processing times, thereby limiting the quantity of the marinade to be absorbed, particularly in marinating larger substrates like turkey meat (Chen, 1982; Lemos et al., 1999; Xargayo et al., 2001; Yusop et al., 2011a). However, this problem can be resolved by increasing marinade strength via incorporating tenderising ingredients such as acids and enzymes. Yusop et al. (2010) found that acidic marinating as a function of pH effect led to an increase in the marinade uptake expressed by the greater final weight and shorter marinating times (120–180 min). Naveena and Mendiratta (2001) observed that marinating of spent hen meat with different concentrations of extract from ginger rhizome permitted enzymatic meat tenderising by increasing protein solubilisation. Another disadvantage of the immersion technique is that it does not provide uniformity and consistency in ingredient distribution unlike tumbling and injection which involve physical manipulation (Yusop et al., 2011a), making this method impractical for the industrial production of marinated meat products. In the seafood industry, immersion has been reported to be enhanced with a combination of thermal processing including cooking and frying, to produce ready-to-eat products that are fit for human consumption (Shenderyuk & Bykowski, 1989). After immersing with salt and acetic acid, the substrate is cooked or blanched and subsequently packed with a gelatin

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

437

solution containing salt, acetic acid and seasonings during the packaging process. The product may also be fried, which allows the formation of Maillard reaction on the substrate’s surface, produces an appealing brown look and taste. The frying step is followed by packaging the fried substrate in the salt and acetic acid solution to allow marinade diffusion. Both aforementioned methods have been successfully utilised in the seafood industry, particularly in marinating fish species like herring, cod and mackerel.

17.5.4 Injection processing The second method of marinating, which is more applicable to the meat industry, is multi-needle injection. This method is perhaps the most widely used because it gives more control over the marinating process by delivering an exact quantity of brine into the meat, thus ensuring consistency and uniformity of marinade dosing of products (Xargayo et al., 2001). Furthermore, the injection processes require much less time than immersion systems and allow the remaining marinade to be reused. In order to deposit the marinade, needles or probes are inserted and the liquid is injected into the meat as the probe or needles are withdrawn, spreading the marinade throughout the entire piece, without the time losses of immersion (Sams, 2003). Yusop et al. (2011a) reported that injection of chicken breast meat when combined with the immersion method produced higher marinade uptake, up to 8% compared with tumbling (6%). This was due to the mechanical action of injection before immersion of meat in the test marinades, which might have contributed to a greater degree of muscle protein denaturation, thereby increasing marinade uptake. These workers also observed that despite the higher marinade uptake, the injection method used produced samples with higher cooking losses. The injection method may also leave holes in the meat, which during cooking allow leakage, resulting in decreased WHC and increased purge and cook loss (Yusop et al., 2011a).

17.5.5 Tumbling and massaging Physical manipulation by tumbling and massaging are successfully utilised in the meat industry because of their ability to facilitate marinade penetration and distribution into meat. The mechanism involved in massaging and tumbling are similar, which includes the extraction of myofibrillar proteins to the surface of the meat to enhance salt and adjunct absorption, which consequently promote cohesion during thermal processing (Addis & Schanus, 1979; Alvarado & McKee, 2007). Many studies reported the efficiency of tumbling in facilitating the distribution of marinades in meat (Babji et al., 1982; Smith & Young, 2007; Yusop et al., 2011a). Owing to the marinade uptake by the muscle and the mechanical action applied during tumbling, the cooked products not only have an enhanced flavour, but

© Woodhead Publishing Limited, 2011

438

Processed meats

generally have an improved tenderness and cooking yield compared with the unmarinated control meat and conventional method of immersion (Babji et al., 1982; Pearson & Gillett, 1996; Yusop et al., 2011a). Currently, most tumblers are equipped with a vacuum that pulls the air out of the unit with a compressor. Tumbling under vacuum prevents air from entering the product and extracts the meat proteins to the surface (Pearson & Gillett, 1996). The vacuum tumbling process has been shown to increase marinade uptake in meat (Young & Lyon, 1997; Young & Smith, 2004) and improve cook yield (Young & Lyon, 1997; Young et al., 2004).

17.6 Established effects of marinating 17.6.1 Marinating improves flavour The incorporation of flavourings and seasonings into marinades is one way of increasing the development of value-added products and meeting consumer demand for variety, new flavours, spiciness and quality presentation. Flavourings and seasonings incorporated via the marinating process enhance flavour characteristics of poultry products by improving basic poultry flavour, restoring flavour loss during processing, providing a unique flavour profile and inhibiting as well as masking warmed over-flavour (Young et al., 1992). Research has also been carried out into the application of non-meat ingredients in marinades, such as salt, phosphate, sugar, red wine, hydrolysed soy protein and honey, to enhance product flavour (Farr & May, 1970; Ruusunen & Puolanne, 2005; Hashim et al., 1999b). Other ingredients that are currently popular are the aqueous flavourings, including aqueous fruit flavourings, which are easily incorporated into marinades. Parks et al. (2000) demonstrated that incorporation of an aqueous apple flavouring into a marinade for chicken resulted in limited changes in the physical or chemical properties of the meat, while sensory properties ranged from ‘neutral’ to ‘like moderately’. Final product yield was not significantly different between control (containing phosphate, salt and spices) and breasts marinated with apple flavouring (0, 0.4, 0.8 and 1.2%). Other effects of marinating on flavour improvement have been shown through the reduction as well as masking, of warmed over-flavour. Warmedover flavour (WOF), an undesirable flavour caused by lipid oxidation and described as ‘cardboard’ or ‘rancid/painty’ (Cross et al., 1987; Ang & Lyon, 1990) sensory notes, has long been recognised as one of the primary causes of quality deterioration in cooked, refrigerated and pre-cooked, frozen meat products (Tims & Watts, 1958). Turkey is reported to be more susceptible than chicken, pork, beef and mutton to WOF (Cross et al., 1987). Many studies have revealed the efficiency of incorporating marinades to reduce WOF in poultry products. Red peppers incorporated into the marinade of a precooked chopped and formed chicken patties at 0.2% and 0.4% positively influenced the development of WOF and oxidative products (Emrick

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

439

et al., 2005). The patties formulated at 0.2% pepper had a less intense WOF than the 0% level, whereas the 0.4% pepper had the least intense WOF. Pepper has the ability to mask flavour intensity and has been found to interfere with some flavour identification (Lawless et al., 1985). Other studies related to the efficiency of marinades in reducing WOF in poultry products include the incorporation of honey (Antony et al., 2000, 2002, 2006; McKibben & Engeseth, 2002; Hashim et al., 1999a, b) and rosemary oleoresin (Keokamnerd et al., 2008).

17.6.2 Marinating affects tenderness Tenderness is rated by consumers as one of the most important facets of the eating quality of meat (McCormick, 1994). Meat tenderness can be related principally to the connective tissue and myofibrillar protein components of muscle, while the relative contribution to tenderness of these components depends on factors such as the carcass location of the muscle, the degree of contraction of the myofibrils, and the cooking procedure applied (Lawrie, 1998). Regardless of meat source, marinating has been well accepted to improve meat tenderness. However, its effect on meat tenderness has been speculatively discussed, especially for commercial marinades, which often have little influence on the tenderness of meat, but instead improve palatability by enhancing or complementing the flavour of meat (Gault, 1991; Rao et al., 1989). Marinades with a tenderising capacity such as acidic and enzymatic solutions are particularly important in applications involving muscles rich in connective tissue. These muscles often make up the cheaper carcass cuts, and the tenderising effect of marinating offers a commercially important means of upgrading them (Gault, 1991; Lewis & Purslow, 1991). Lyon et al. (1998) found that the combination of chicken carcass stimulation during bleeding and muscle marinating after chilling by immersing samples in a salt/phosphate solution for 0 to 1.5 h resulted in Warner–Bratzler shear values that would be considered ‘very tender’ based on a sensory panel’s perception. As a result, companies marketing marinated whole breast products can eliminate post-chill ageing by increasing tenderness through marinating. Barbanti & Pasquini (2005) assessed industrial skinless chicken breast meat samples, which were marinated and cooked in an oven by hot air/hot airsteam mixture at 130, 150 and 170°C, for 4, 8 and 12 minutes, respectively. Results showed that marinating, followed by air steam cooking, are the best combinations to obtain the most tender chicken breast slices. Naveena and Mendiratta (2001) determined the effect of marinating using ginger extract (GE) on spent hen meat tenderness. Meat from spent hens is generally tough, and poor in functional properties because of its increased collagen content and cross-linkages (Bailey, 1984). The authors observed an increased sensory score for tenderness, juiciness, appearance, flavour and overall acceptability by the GE-treated samples. It was also

© Woodhead Publishing Limited, 2011

440

Processed meats

observed that post-chilling spent hen meat with 3% GE for 24 h to be optimum for tenderisation.

17.6.3 Marinating effects on processing yields The ultimate benefit of marinating from an industrial perspective is the increase of raw meat’s yield by improving WBC. The addition of waterbinding agents such as salt, phosphate, starches, soy proteins and gums, and their combination with technologies such as tumbling and massaging, contribute largely to the increase in yield of the marinated product. All of these attributes translate into a higher profit for the producer; however, these benefits are negligible if they do not also positively affect the eating quality of the marinated product. Proctor and Cunningham (1987) evaluated the effects of marinating on weight gain and coating characteristics of broiler drumsticks. The authors concluded that skinless drumsticks marinated in 4% Kena solution, which consists of 90% sodium tripolyphosphate (STPP) and 10% GLASS phosphate had significantly greater coating pickup and reduced cooking losses than other marinating treatments, including; 2% NaCl, 0.5% ascorbic acid and 0.002% papain. Naveena & Mendiratta (2001) found that by marinating meat chunks from spent hens at either pre- or post-chilled stages with different concentrations of GE (1–5%) resulted in the increase of cooking yield. Chen (1982) in his study found that by coating and deep-fat frying broiler parts (168°C, 12 minutes) marinated by either still-marinating or marinating in a hexagonal-shaped drum rotated at 31.5 rpm, resulted in increased frying yields. Detienne et al. (2000) evaluated the injection of low methoxyl pectin (LMP) and amidated low methoxyl pectin (LMP-A) in the absence of added salt as ingredients to improve yield and quality of marinated poultry. As an alternative to phosphate, LMP demonstrated an ability to bind water and increased cook yields and total moisture in marinated cooked chicken breasts.

17.6.4 Marinating affects colour Meat colour is the total impression observed visually and influenced by the viewing conditions (Aberle et al., 2001). Several researchers have reported the significant contribution that marinating provides in improving colour properties of marinated meat. These are generally divided into two categories: improving the colour of raw meat products and the appearance of meat for the ethnic flavour market. Allen et al. (1998) divided visibly light- and dark-coloured breast fillets into marinated (3% STP and 7% NaCl at 10% wt/wt) and control groups, and vacuum tumbled them for 20 minutes at 4 °C under 80 kPa pressure. They found lightness values increased when all fillets were marinated. Yang and Chen (1993) conducted a trial evaluating the effects of refrigerated

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

441

storage, pH adjustment, and marinating on colour of raw and microwaved cooked chicken meat. A decrease in pH, as a result of marinating in citric acid, showed increased lightness values and decreased redness values in raw breast fillets. The study concluded that pH values play an important role in cooked chicken products, and recommended the use of acidulant ingredients such as citric acid and avoiding the use of alkaline products for marinating in order to prevent discoloration and pinkness in the cooked product. Yusop et al., (2009b) evaluated the sensory acceptability of chicken breast fillet marinated with several retail and commercially available Chinese-style marinades. These authors observed that the acceptability of the Chinesestyle marinated chicken was largely governed by the aroma and flavour liking. Interestingly, when judging similar products with superior aroma and flavour quality, the consumers chose samples with the highest score for bright red and dark brown colours. This result suggested that colour quality could be the second most important factor in determining the acceptability of ethnic-marinated chicken after flavour liking.

17.7 The significance of sensory evaluation in determining quality of marinated products Understanding cross-cultural sensory perception and preference of food products is a crucial step in ensuring success in both domestic and international food retail markets (Yusop et al., 2009b). Sensory evaluation has always been applied as a tool to collect insightful information from diverse cultures in a rapid, direct and cost-effective manner (Forde, 2006). In the case of marinated products, aspects such as marinade ingredients, techniques, process conditions and equipment continue to be updated and refined to improve the quality characteristics of the final products as well as provide satisfactory product with broad consumer appeal. Thus, the multivariate nature of sensory experience needs a powerful tool like multivariate analysis to understand the complex relationships of the instrumental and sensory properties of food products and the sensory capacity of consumers. Yusop et al. (2009a, b) studied the sensory acceptability of the commercially available ethnic-flavoured marinated chicken in Ireland on different cultural groups. The first step consisted of generating a list of descriptive terms of the test marinades by a team of expert panellists, which were then screened, grouped and refined until a consensus of list terms was chosen to best describe the marinade test products. The intensity for each attribute was rated on a 10 cm line scale labelled with words; words showing weak intensities on the left and stronger intensities on the right at both ends, respectively. Yusop et al. (2009a) reported that, despite differences in cultural and dietary habits between Malaysians and Europeans, a similar pattern of sensory acceptability between the two groups toward

© Woodhead Publishing Limited, 2011

442

Processed meats 1.0 0.8 0.6 0.4

PC3

0.2 0.0 –0.2 –0.4

Moisture

–0.6

Colour b* Colour L*

–0.8 –1.0 –1.0

pH HO-P HO-L HO-O FS-R Spicy aroma HO-K HO-M Juiciness BBQ HO-N c. PenetrationAuthenticity Fat Pungent SS-I SS-J SZ-B Flav liking Spicy flay Aroma liking FS-Q Colour a* SZ-C noisin Overall acceptability Sweet&sour SZ-A Hot flav. Bright red SS-E Dark brown SS-G Szechuan Chinese 5 spice SS-H SS-F SZ-D

–0.8

–0.6

–0.4

–0.2

0.0

0.2

0.4

0.6

0.8

1.0

PC1

Fig. 17.4 Overview of the variation found in the data from the ANOVA-Partial Least Squares Regression (APLSR) correlation loadings plot for the European naïve assessor group. Shown are the loadings for the X- and Y-variables for PC1 (Principal Component 1) versus PC3 (Principal Component 3). ▲ = sample marinade, • = sensory descriptor, Physical and instrumental variables. The dotted ellipse highlights samples and attributes which are highly correlated to each other (adapted from Yusop et al., 2009b).

Indian-style marinated chicken was observed. In contrast, Yusop et al. (2009b) observed that the European and Chinese groups perceived Chinese-style marinated chicken very differently, with an interesting observation on the European assessors, who successfully differentiated the Chinese marinade products according to the four specific flavour groups (Szechuan, Sweet and sour, Hoisin and Chinese 5 spice) compared to the Chinese assessors. The authors concluded that consumer familiarity and exposures towards foods, as well as product’s authenticity and flavour quality, greatly affect the acceptability of marinated meat products (Yusop et al., 2009a, b) (Fig. 17.4).

17.8 Future research in marinating technology Owing to the growing demand for value-added and ethnically flavourful muscle food products, there will be a continuous requirement to improve

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

443

marinated products, as well as related technology, in the future. The understanding of ethnic marinade flavours through the use of sensory evaluation should be carefully implemented when developing and optimising marinated products for both local and international markets. More attention should be paid to the flavour authenticity and flavour acceptability of marinated products as these are the primary reasons that drive the consumption and purchasing of ethnic-marinated products by consumers (Yusop et al., 2009a, b). The enhancement of meat quality characteristics through the use of marinating technology such as immersion, injection, massaging and tumbling of liquid solutions has been shown to improve the overall acceptability of muscle products. The potential of marinating in producing healthier products by reducing the carcinogenic compounds formed during cooking of meat has also been shown experimentally (Gibis & Weiss, 2010; Lan & Chen, 2002; Lan et al., 2004; Salmon et al., 1997; Skog et al., 1998). However, the information on the effect of marinating in improving the shelf-life of meat products is required more than ever as the current information is still scarce and rather contradictory. Technologies such as high pressure processing and modified atmosphere packaging may enhance poultry and meat product safety and quality by acting as hurdles for bacterial growth without affecting the marinated product’s sensory quality such as flavour, colour and overall appearance. Also active packaging is a recent innovation which can be used in the extension of the shelf-life of meat and poultry products. It has the advantage of maintaining the preservative effects of various compounds (antimicrobial, antifungal or antioxidant), but without being in direct contact with the food product. This is an important development, considering the consumer drive toward clean labelling of food products and the desire to limit the use of food additives (O’Sullivan and Kerry, 2009). The marinating industry could also benefit from the advent of nanotechnology that at present has emerged to be multifaceted. Yusop et al. (2011b) used nano-scale ingredients in marinade systems. They found that marinating chicken meat by using nanoparticle paprika successfully and simultaneously enhanced the marinating performance of meat products. This may benefit manufacturers by eliminating time and cost, related to a prolonged marinating holding time. In addition, future work involving the incorporation of functional nanoparticle ingredients containing substances such as antimicrobials, antioxidants as well as flavours and colours will certainly benefit the marinating industry by adding more values to meat as well as rapid marinating process times.

17.9 References and further reading aberle, e.d., forrest, j.c., gerrard, d.e. & mills, e.w. (2001). Principles of Meat Science. Kendall/Hunt Publishing Co., Dubuque.

© Woodhead Publishing Limited, 2011

444

Processed meats

addis, p.b. & schanus, e.b. (1979). Massaging and tumbling in the manufacture of meat products. Food Technology, 33, 36–39. adler-nissen, j. & olsen, h.s. (1979). The influence of peptide chain length on taste and functional properties of enzymatically modified soy protein. In: Functionality and Protein Structure, American Chemical Society Symposium Series, vol. 92, 125–146. aguirrezábal, m.m., mateo, j., domínguez, m.c. & zumalacárregui, j.m. (2000). The effect of paprika, garlic and salt on rancidity in dry sausages. Meat Science, 54, 77–81. aidells, b. (2006). Brining with Bruce Aidells. Cooking Light http://www.cookinglight.com/cooking/package/0,14343,734675,00.html. Accessed Dec 28, 2006. aidells, b. & kelly, d. (2001). Complete Meat Cookbook: A Juicy and Authoritative Guide to Selecting, Seasoning, and Cooking Today’s Beef, Pork, Lamb, and Veal. Houghton Mifflin, Parek Avenue, New York. allen, c.d., fletcher, d.l., northcutt, j.k. & russell, s.m. (1998). The relationship of broiler breast color to meat quality and shelf-life. Poultry Science, 77, 361–366. alvarado, c.z. & mckee, s. (2007). Marinating to improve functional properties and safety of poultry meat. Journal of Applied Poultry Research, 16, 113–120. ang, c.y.w. & lyon, b.g. (1990). Evolutions of warmed-over flavour during chill storage of cooked broiler breast, thigh and skin by chemical, instrumental and sensory methods. Journal of Food Science, 55, 644–648, 673. anon. (2003). Art Culinaires. www.findarticles.com on dry marinades. Accessed May 2010. antony, s., rieck, j.r. & dawson, p.l. (2000). Effect of dry honey on oxidation in turkey breast meat. Poultry Science, 79, 1846–1850. antony, s.m., han, i.y., rieck, j.r. & dawson, p.l. (2002). Antioxidative effect of Maillard products added to turkey meat during heating by addition of honey. Journal of Food Science, 67, 1719–1724. antony, s., rieck, j.r., acton, j.c., han, i.y., halpin, e.l. & dawson, p.l. (2006). Effect of dry honey on the shelf life of packaged turkey slices. Poultry Science, 85, 1811–1820. babji, a.s., froning, g.w. & ngoka, d.a. (1982). The effect of short-term tumbling and salting on the quality of turkey breast muscle. Poultry Science, 61, 300–303. bailey, a.j. (1984). The chemistry of intramuscular collagen. In: Recent Advances in the Chemistry of Meat. The Royal Society of Chemistry, London. barbanti, d. & pasquini, m. (2005). Influence of cooking conditions on cooking loss and tenderness of raw and marinated chicken breast meat. LWT–Food Science and Technology, 38, 895–901. bater, b., descamps, o. & maurer, a. (1993). Quality characteristics of hydrocolloidadded oven roasted turkey breasts. Poultry Science, 72, 349–354. berge, p., ertbjerg, p., larsen, l.m., astruc, t., vignon, x. & moller, a.j. (2001). Tenderization of beef by lactic acid injected at different times post mortem. Meat Science, 57, 347–357. bertram, h.c., meyer, r.l., wu, z., zhou, x. & andersen, h.j. (2008). Water distribution and microstructure in enhanced pork. Journal of Agriculture and Food Chemistry, 56, 7201–7207. birk, t., grønlund, a.c., christensen, b.b., knøchel, s., lohse, k. & rosenquist, h. (2010). Effect of organic acids and marination ingredients on the survival of Campylobacter jejuni on meat. Journal of Food Protection, 73, 258–265. bjorkroth, j. (2005). Microbiological ecology of marinated meat products. Meat Science, 70, 477–480. bloukas, j.g., arvanitoyannis, i.s. & siopi, a.a. (1999). Effect of natural colourants and nitrites on colour attributes of frankfurters. Meat Science, 52, 257–265.

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

445

bowker, b.c., callahan, j.a. & solomon, m.b. (2010). Effects of hydrodynamic pressure processing on the marination and meat quality of turkey breasts. Poultry Science, 89, 1744–1749. burke, r.m. & monahan, f.j. (2003). The tenderization of shin beef using a citrus juice marinade. Meat Science, 63, 161–168. canning, k. (2004). A lasting impression: marinades, when formulated and applied correctly, can boost product safety and extend shelf life. http://www.allbusiness. com/manufacturing/food-manufacturing/188926-1.html. Accesssed March 3, 2007. capita, r., alonso-calleja, c. sierra, m., moreno, b. & garcia-fernandez, m.c. (2000). Effect of trisodium phosphate solutions washing on the sensory evaluation of poultry meat. Meat Science, 55, 471–474. carlos, a.m.a. & harrison, m.a. (1999). Inhibition of selected microorganisms in marinated chicken by pimento leaf oil and clove oleoresin. Journal of Applied Poultry Research, 8, 100–109. chen, t. (1982). Studies on the marinating of chicken parts for deep-fat frying. Journal of Food Science, 47, 1016–1019. cheng j.h. & ockerman h.w. (2003). Effect of phosphate with tumbling on lipid oxidation of precooked roast beef. Meat Science, 65(4),1353–1359. choi, y.m., bae, y.y., kim, k.h., kim, b.c. & rhee, m.s. (2009). Effects of supercritical carbon dioxide treatment against generic Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and E. coli O157:H7 in marinades and marinated pork. Meat Science, 82, 419–424. coggins, p. (2001). Spices and Flavorings for Meat and Meat Products, Marcel Dekker, Inc., New York. cross, h.r., leu, r. & miller, m.f. (1987). Scope of warmed-over flavor and its importance to the meat industry. In: A.J. St. Angelo and M.E. Bailey (Eds). Warmedover Flavor of Meat, Academic Press, Inc., New York. detienne, n.a., zheng, m., barnes, b.w. & wicker, l. (2000). Properties of chicken breasts injected with low methoxyl pectin. Foodservice Research International, 12, 151–161. emrick, m.e., penfield, m.p., bacon, c.d., van laack, r.v.l. & brekke, c.j. (2005). Heat intensity and warmed-over flavor in precooked chicken patties formulated at 3 fat levels and 3 pepper levels. Journal of Food Science, 70, 600–604. farr, a.j. & may, k.n. (1970). The effect of polyphosphates and sodium chloride on cooking yields and oxidative stability of chicken. Poultry Science, 49, 268–275. feng, j. & xiong, y.l. (2002). Interaction of myofibrillar and preheated soy proteins. Journal of Food Science, 67, 2851–2856. feng, j. & xiong, y.l. (2003). Interaction and functionality of mixed myofibrillar and enzyme-hydrolyzed soy proteins. Journal of Food Science, 68, 803–809. ferrell, k.t. (1990). Spices, Condiments and Seasonings, 2nd Edition. AVI, New York. forde, c.g. (2006). Cross cultural sensory analysis in the Asia-Pacific region (abstract). Food Quality and Preference, 17, 646–649. gault, n.f.s. (1984). The influence of acetic acid concentration on the efficiency of marinating as a process for tenderising beef. In: Proceedings of the 30th European meeting of meat research workers (pp. 184–185). gault, n.f.s. (1985). The relationship between water-holding capacity and cooked meat tenderness in some beef muscles as influenced by acidic conditions below the ultimate pH. Meat Science, 15, 15–30. gault, n.f.s. (1991). Marinaded meat. In R. Lawrie (Ed.) Developments in Meat Science. Elsevier Science, London. gibis, m. (2007). Effect of oil marinades with garlic, onion, and lemon juice on the formation of heterocyclic aromatic amines in fried beef patties. Journal of Agriculture and Food Chemistry, 55, 10240–10247.

© Woodhead Publishing Limited, 2011

446

Processed meats

gibis, m. & weiss, j. (2010). Inhibitory effect of marinades with hibiscus extract on formation of heterocyclic aromatic amines and sensory quality of fried beef patties. Meat Science, 85, 735–742. gómez, r., alvarez-orti, m. & pardo, j.e. (2008). Influence of the paprika type on redness loss in red line meat products. Meat Science, 80, 823–828. gorsuch, v. & alvarado, c.z. (2010). Postrigor tumble marination strategies for improving color and water-holding capacity in normal and pale broiler breast fillets. Poultry Science, 89, 1002–1008. grey, t.c., robinson, d. & jones, j.m. (1978). The effects on broiler chicken of polyphosphate injection during commercial processing: changes in weight and texture. Journal of Food Technology, 13, 529–540. hashim, i.b., mcwatters, k.h. & hung, y.c. (1999a). Marination method and honey level affect physical and sensory characteristics of roasted chicken. Journal of Food Science, 64, 163–166. hashim, i.b., mcwatters, k.h. & hung, y.c. (1999b). Quality enhancement of chicken baked without skin using honey marinades. Poultry Science, 78, 1790–1795. hayes, j.e., kenny, t.a., ward, p. & kerry, j.p. (2007). Development of a modified dry curing process for beef. Meat Science, 77, (3), 314–323. hirasa, k. & takemasa, m. (1998). Spice Science & Technology. Marcel Dekker, Inc., New York. hyk, d. (2001). Further processing: the trends in injecting/marinating systems. Poultry. February Issue. pp. 40. keokamnerd, t., acton, j.c., han, i.y. & dawson, p.l. (2008). Effect of commercial rosemary oleoresin preparations on ground chicken thigh meat quality packaged in a high-oxygen atmosphere. Poultry Science, 87, 170–179. kim, c.r. & marshall, d.l. (2000). Quality evaluation of refrigerated chicken wings treated with organic acids. Journal of Food Quality, 23, 327–335. lan, c. & chen, b. (2002). Effects of soy sauce and sugar on the formation of heterocyclic amines in marinated foods. Food Chemistry and Toxicology, 40, 989–1000. lan, c.m., kao, t.h. & chen, b.h. (2004). Effects of heating time and antioxidants on the formation of heterocyclic amines in marinated foods. Journal of Chromatography B, 802(1), 27–37. lawless, h.t., rozin, p. & shenker, j. (1985). Effects of oral capsaicin on gustatory, olfactory and irritant sensations and flavour identification in humans who regularly or rarely consume chili pepper. Chemical Senses, 10, 579–589. lawrie, r.a. (1998). The conversion of muscle to meat. In: Lawrie’s Meat Science, 6th ed. Woodhead Publishing Ltd, Cambridge, VIT, p. 96–118. leatherhead food international (2007). The European ethnic food markets (3rd ed.). http://www.leatherheadfood.com/lfi/pdf/ethnicfoods07.pdf. Accessed January 18, 2009. lemos, a.l.s.c., nunes, d.r.m. & viana, a.g. (1999). Optimization of the still-marinating process of chicken parts. Meat Science, 52, 227–234. lewis, g.j. & purslow, p.p. (1991). The effect of marinating and cooking on the mechanical properties of intramuscular connective tissue. Journal of Muscle Foods, 2, 177–195. lunde, k., egelandsdal, b., choinski, j., mielnik, m., flåtten, a. & kubberød, e. (2008). Marinating as a technology to shift sensory thresholds in ready-to-eat entire male pork meat. Meat Science, 80, 1264–1272. lynn, p. (2004). Key ingredient: decades after its first meat and poultry applications, phosphate remains a remarkably flexible and effective addition to both processed and fresh meats. The National Provisioner. http://www.allbusiness.com/ manufacturing/food-manufacturing/242352-1.html. Accessed May 2010.

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

447

lyon, c.e., lyon, b.g. & dikens, j.a. (1998). Effects of carcass stimulation, deboning time, and marinating on colour and texture of broiler breast meat. Journal of Applied Poultry Research, 7, 53–60. mandava, r. & hoogenkamp, h. (1999). The role of processed products in the poultry meat industry. In: Poultry Meat Science. R. I. Richardson and G.C. Mead, (eds) Poultry Science Symposium Series, Vol. 25. CABI Publishing, Wallingford, Oxon, United Kingdom. mccormick, r.j. (1994). The flexibility of the collagen compartment of muscle. Meat Science, 36, 79–91. mckibben, j. & engeseth, n.j. (2002). Honey as a protective agent against lipid oxidation in ground turkey. Journal of Agriulture and Food Chemistry, 50, 592–595. melo, a., viegas, o., petisca, c., pinho, o. & ferreira, i.m.p.l.v.o. (2008). Effect of beer/red wine marinades on the formation of heterocyclic aromatic amines in pan-fried beef. Journal of Agriulture and Food Chemistry, 56, 10625–10632. naveena, b.m. & mendiratta, s.k. (2001). Tenderisation of spent hen meat using ginger extract. British Poultry Science, 42, 344–349. offer, g. & cousins, t. (1992). The mechanism of drip production: formation of two compartments of extracellular space in muscle post-mortem. Journal of the Science of Food and Agriculture, 58, 107–116. offer, g. & knight, p. (1988). The structural basis of water-holding in meat. Part 1: General principles and water uptake in meat processing. In: R. Lawrie (Ed.), Development in Meat Science. Elsevier Science, London. oreskovich, d.c., bechtel, p.j., mckeith, f.k., novakofski, j. & basgall, e.j. (1992). Marinade pH affects textural properties of beef. Journal of Food Science, 57, 305–311. o’sullivan, m.g & kerry, j.p. (2009). CH 13, Meat Packaging. In: F. Toldrá (ed.), Handbook of Meat Processing. John Wiley & Sons, Chichester, 211–230. parks, s.s., reynolds, a.e. & wicker, l. (2000). Aqueous apple flavoring in breast muscle has physical, chemical, and sensory properties similar to those of phosphate-marinated controls. Poultry Science, 79, 1183–1188. pearson, a.m. & gillett, t.a. (1996). Sectioned and formed meat products. In: Processed Meats. 3rd edn. Chapman and Hall, New York, NY. pietrasik, z., aalhus, j.l., gibson, l.l. & shand, p.j. (2010). Influence of blade tenderization, moisture enhancement and pancreatin enzyme treatment on the processing characteristics and tenderness of beef semitendinosus muscle. Meat Science, 84, 512–517. proctor, v.a. & cunningham, f.e. (1987). Influence of marinating on weight gain and coating characteristics of broiler drumsticks, Journal of Food Science, 52, 286. puolanne.e. & ruusunen, m. (2009). Reducing salt in meat products. http://www. fsai.ie/uploadedFiles/Science_and_Health/Salt_and_Health/Presentation_University_Helsinki.pdf. Accessed May, 2010. rao, m.v., gault, n.f.s. & kennedy, s. (1989). Changes in the ultra-structure of beef muscle as influenced by acidic conditions below the ultimate pH. Food Microstructure, 8, 115. ruusunen, m. & puolanne , e. (2005). Reducing sodium intake from meat products. Meat Science, 70, 531–541. salmon, c.p., knize, m.g., felton, j.s. (1997). Effects of marinating on heterocyclic amine carcinogen formation in grilled chicken. Food and Chemical Toxicology, 35, 433–441. sams, a.r. (2003). Dr. marinade: marination is not just for flavor anymore: remedial marination can correct problems. WATT Poult USA, 4, 18–25. schirmer, b.c. & langsrud, s. (2010a). Evaluation of natural antimicrobials on typical meat spoilage bacteria in vitro and in vacuum-packed pork meat. Journal of Food Science, 75, M98–M102.

© Woodhead Publishing Limited, 2011

448

Processed meats

schirmer, b.c. & langsrud, s. (2010b). A dissolving CO2 headspace combined with organic acids prolongs the shelf-life of fresh pork. Meat Science, 85, 280–284. shand, p.j., sofos, j.n. & schmidt, g.r. (1993). Properties of algin/solcalcium and salt/ phosphate structured beef rolls with added gums. Journal of Food Science, 58, 1224–1230. shenderyuk, v.i. & bykowski, p.j. (1989). Salting and marinating of fish. In Z.E. Sikorski (Ed.), Seafood: Resources, Nutritional Composition and Preservation, CRC Press, Inc, Boca Raton, FL, 147–162. skog, k.i., johannsson, m.a. & jagerstad, m.i. (1998). Carcinogenic heterocyclic amines in model systems and cooked foods: A review on formation, occurrence and intake. Food and Chemical Toxicology, 36(9–10), 879–896. smith, d. (2001). Functional properties of muscle proteins in processed poultry products. In A.R. Sams (ed.), Poultry Meat Processing, CRC Press, Boca Raton, FL, 181–194. smith, d.p. & acton, j.c. (2001). Marination, cooking, and curing of poultry products. In A.R. Sams (ed.), Poultry Meat Science, CRC Press, Boca Raton, FL, 257–280. smith, d.p. & young, l.l. (2007). Marination pressure and phosphate effects on broiler breast fillet yield, tenderness, and color. Poultry Science, 86, 2666–2670. stanton, c. & light, n. (1990). The effects of conditioning on meat collagen: Part 4. The use of pre-rigor lactic acid injection to accelerate conditioning in bovine meat. Meat Science, 27, 141–159. suderman, d.r. (1993). Selecting flavorings and seasonings for batter and breading systems. Cereal Foods World, 38, 689–694. tarté, r. & amundson, c.m. (2006). Protein interactions in muscle foods. In A.G. Gaonkar & A. Mcpherson (Eds.), Ingredient Interactions: effects on Food Quality (2nd ed.) CRC Press, Boca Raton, FL, 195–283. tims, m.j. & watts, b.m. (1958). Protection of cooked meats with phosphates. Food Technology, 12, 240. toledo, r.t. (2001). Marination technologies. Technical Program Listing 2001 IFT Annual Meeting, June 23–27; New Orleans, LA. toledo, r.t. (2007). Overvue of Marination Technology. Advances in Marination Science & Technology. The University of Georgia. usda’s food safety and inspection service (fsis). http://www.fsis.usda.gov/OPPDE/ larc/Policies/Labeling_Policy_Book_082005_2.pdf. Accessed July, 2010. walsh, h., martins, s., o’neill, e.e., kerry, j.p., kenny, t. & ward, p. (2010). The effect of sodium lactate, potassium lactate, carrageenan, whey protein. Meat Science, 85, 230–234. wenham, l.m. & locker, r.h. (1976). The effect of marinating on beef. Journal of the Science of Food and Agriculture, 27, 1079–1084. woods, k.l., rhee, k.s. & sam, a.r. (1997). Tenderizing spent fowl meat with calcium chloride.4. Improved oxidative stability and effects of additional aging. Poult Sci, 76, 548–551. woods, l.f.j. & church, p.n. (1999). Strategies for extending the shelf-life of poultry meat and products. In R.I. Richardson and G.C. Mead (Eds.), Poultry Meat Science, Poultry Science Symposium Series, Volume 25, CABI Publishing, New York, 397–410. xargayo, m., lagares, j., fernandez, e., ruiz, d. & borrell, d. (2001). Marinating of fresh meats by means of spray effect: influence of spray injection on the quality of marinated products. http://www.metalquimia.com. Accessed Sept. 2009. xiong, y.l. (2005). Role of myofibrillar proteins in water-binding in brine-enhanced meats. Food Research International, 38, 281–287. xiong, y.l. & kupski, d.r. (1999a). Monitoring phosphate marinade penetration in tumbled chicken fillets using a thin-slicing, dye-tracing method. Poultry Science, 78, 1048–1052.

© Woodhead Publishing Limited, 2011

Marinating and enhancement of nutritional content

449

xiong, y.l. & kupski, d.r. (1999b). Time-dependent marinade absorption and retention, cooking yield and palatability of chicken fillet marinated in various phosphate solutions. Poultry Science, 78, 1053–1059. yang, c.c. & chen, t.c. (1993). Effects of refrigerated storage, pH adjustment, and marinade on color of raw and microwave cooked chiken meat. Poultry Science, 72, 355–362. young, l.l. & lyon, c.e. (1997). Effect of aging and sodium tripolyphosphate on moisture binding properties, color, and Warner–Bratzler shear values of chicken breast meat. Poultry Science, 76, 1587–1590. young, l.l. & smith, d.p. (2004). Moisture retention by water- and airchilled chicken broilers during processing and cutup operations. Poultry Science, 83, 119–122. young, l.l., papa, c.m., lyon, c.e. and wilson, r.l. (1992). Moisture retention and textural properties of ground chicken meat affected by sodium tripolyphosphate, ionic strength, and pH. Journal of Food Science, 57, 1291–1293. young, l.l., smith, d.p., cason, j.a. & walker, j.m. (2004). Effect of intact carcass electrical stimulation on moisture retention characteristics of polyphosphatetreated non-aged boneless broiler breast fillets. International Journal of Poultry Science, 3, 796–798. yusop, s.m., o’sullivan, m.g., kerry, j.f. & kerry, j.p. (2009a). Sensory evaluation of Indian-style marinated chicken by Malaysian and European naive assessors. Journal of Sensory Studies, 24, 269–289. yusop, s.m., o’sullivan, m.g., kerry, j.f. & kerry, j.p. (2009b). Sensory evaluation of Chinese-style marinated chicken by Chinese and European naive assessors. Journal of Sensory Studies, 24, 512–533. yusop, s.m., o’sullivan, m.g., kerry, j.f. & kerry, j.p. (2010). Effect of marinating time and low pH on marinade performance and sensory acceptability of poultry meat. Meat Science, 85, 657–663. yusop, s.m., o’sullivan, m.g., kerry, j.f. & kerry, j.p. (2011a). Influence of processing method and holding time on the physical and sensory quality of cooked marinated chicken. LWT – Food Science and Technology (submitted). yusop, s.m., o’sullivan, m.g., preuss m., weber, h., kerry, j.f. & kerry, j.p. (2011b). Assessment of nanoparticle paprika oleoresin in marinating performance and sensory acceptance of poultry meat. LWT – Food Science and Technology (submitted). zheng, m., toledo, r. & wicker, l. (1999). Effect of phosphate and pectin on quality and shelf-life of marinated chicken breast. Journal of Food Quality, 22, 553–564.

© Woodhead Publishing Limited, 2011

18 Improving the quality of restructured and convenience meat products M. M. Farouk, AgResearch Limited, New Zealand

Abstract: This chapter discusses some of the quality problems associated with whole-tissue restructured and convenience meats and ways of improving such problems. The chapter reviews recent relevant literature on the aesthetic, oral, aroma, and convenience-related problems and their solutions with emphasis on firstly the applied aspects rather than the fundamental and secondly meats from some of the larger common animal species such as cattle, sheep, deer, goats and pigs. Key words: whole-tissue, restructured meats, convenience meats, packaging, quality improvement.

18.1 Introduction The demand for restructured and convenience meats is growing very fast, fuelled by consumer desire for convenience and enabled by technological advancement (Sloan, 2000; RTS, 2006; Datamonitor, 2007). Restructured and convenience meats are very difficult to define owing to the many ways and forms they are produced, packaged and consumed. The main objective of restructuring meat is to bind meat pieces to produce a product that possesses the attribute of whole-tissue product or the real McCoy; and convenience meats are supposed to possess all the desired quality attributes and still save the consumer time and effort in their preparation and consumption (Pearson and Gillett, 1999; Buckley et al., 2007). Therefore, anything that hinders restructured and convenience meats from achieving these objectives constitutes a problem that should be addressed. However, any steps taken to address these problems must balance the need to maintain the overall quality of the final product – not just a few attributes at the expense of the others – and must also factor in cost, potential risk to health, environmental effect and even carbon footprint in the overall considerations.

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

451

This chapter discusses some of the challenges associated with restructured and convenience meats and ways of mitigating/improving such issues with particular emphasis on restructured and convenience whole-tissue meats from some of the larger common animal species.

18.2 Restructured whole-tissue and convenience meat products 18.2.1 Restructured whole-tissue meats Broadly defined, restructuring means the partial or complete disassembling of muscles or meat and then hot- or cold-set binding the pieces back together to form a cohesive mass that possesses some of the qualities of an intact muscle or meat (Pearson and Gillett, 1999). Hot-set binding systems require heat to ‘set’ the bind, which produces a cooked product, while in a cold-set system no heat is required; the bind is achieved on the raw meat. In this chapter the term ‘restructured whole-tissue meat’ is used to define products manufactured from whole boneless cuts comprising a number of intact or sections of muscles that are bound together using hot- or cold-set binding systems. Some of the terminology used to describe some restructured meats in commerce includes boneless beef fillet (heat and serve restructured microwaveable steak), sandwich steaks, joysteak, ribsteak, grillsteak, sandwich meat, reformed steaks, reformed roast/joints, lamb medallion, and meat cutlets (Pork McRibs). Restructured products can be in the form of strips, cubes, coarsely or thinly sliced, shaved or diced to any shape and size; they may represent the centre of the plate entrée or may be included as ingredients in ready meals; and they could be categorised as convenience or processed meats.

18.2.2 Convenience whole-tissue meats It is difficult to define convenience foods as Buckley et al. (2007) found when they reviewed a number of definitions of the term; they suggested convenience be defined in terms of ‘the time, physical energy and mental effort savings offered to the consumer in food-related activities’. Therefore, in this chapter, convenience meats are defined as meats that save the consumer time and effort in their purchase, preparation, consumption and post-consumption-related activities such as cleaning and waste disposal. This definition is broad enough to include a wide range of products and the terminologies used in their description including value-added, pre-packaged, pre-seasoned, marinated, pre-sliced, ready-to-cook, ready-to-heat, microwavable, shelf-stable, heat-and-eat, heat-and-serve, ready-to-eat, deli, delicatessens, specialty and processed meats.

© Woodhead Publishing Limited, 2011

452

Processed meats

Convenience meats can be processed from whole-tissue bone-in or boneless meat cuts or meat that is emulsified or finely or coarsely ground. The meats can be consumed as snacks, ingredients in meal solutions or in complete meals such as in sandwiches, ready meals, home meal replacements or scratch-meals cooked at home or restaurants. Manrique and Jensen (1997) included commercially frozen or pre-cooked steaks, roasts, ground beef, veal and pork; sausages, cured and smoked ham (cold cuts); ready-toeat beef, pork, chicken, or seafood frozen dishes, ready-to cook items; seasoned, marinated meats; pre-stuffed poultry and seafood; fish fillets as well as ready-to-eat breaded, shucked, or commercially canned meat and seafood products as convenience meats. Because of the wide range of products that fit the definition of convenience meats, this chapter emphasises pre-cooked convenience meats from whole-tissue/muscle meat cuts of some of the larger common animal species that are merchandised alone or as part of a ready meal. Examples of such products are found in posters (Fig. 18.1(a) and (b)) by Farouk et al. (2002) presenting a number of value-added/convenient products from intact or restructured whole-tissue/muscle from New Zealand bull beef and lamb. The range of products represented in the posters is just a drop in the ocean of convenience meats found around the world. Others commercially available include • whole-tissue portioned controlled steak sandwich meat, fully cooked corned beef, roast beef, and pastrami marketed by ANZCO Foods Ltd a leading New Zealand food company (ANZCO, 2009); • Tyson’s Fully Cooked Heat ‘N Eat Dinner Meats including Beef Brisket in Fire Roasted Onion Sauce, Braised Beef Brisket with Mild Chili Sauce, Beef Steak Tips in Burgundy Sauce, and Pork Loin in Sweet & Tangy BBQ Sauce (Saltzer, 2009); • line shaved Deli Roast Beef by Oscar Mayer and Hormel’s Natural Choice Roast Beef lunchmeat (Pellegrini, 2007); • the fully cooked shelf-stable Karoolamb shanks by Karoocuisine in UK (Anon, 2006a); • Turkey’s Black Angus Ranch Roast Beef (Sloan, 2008); • Dawn Meats microwaveable lamb with leeks, lamb shank with minted gravy, pork with sage and hickory smoked pork ribs (Bedington, 2002); • Prairie Grove’s fully cooked all-natural pork ribs (Anon, 2004); • Hormel’s shelf-stable microwaveable Beef Steak & Pepper and Homestyle Beef (Swientek, 2008); • fully cooked refrigerated beef and pork entrées such as pot roast, garlic peppercorn pork roast, BBQ shredded beef, roast beef and gravy, boneless chuck fillet, and tender beef tips and gravy introduced by Excel Specialty Products under their Butcher & Cook brand (Savage, 1999); and • beef and lamb joints in gravy, pork loin steaks and BBQ beef ribs from Kepak Group Ireland.

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

Top Seam

These products were developed Heal Meat as part of a contract to Meat & Pre-cooked Wool New Zealand funded by Roast farmer levies.

Marinated or Restructured Steaks Ready Roast Top side Cap Steaks Top Seam

Loose Cover Pre-cooked Roast

Corner Cut Restructured Breaded Jerky Beef

Steaks

Roast

Eye of Round Roast Steaks

Tritip Steaks

Healmeat

Thick Skirt Steaks

Flank Skirt Smoked Beef Strips

Tenderloin

Thick Skirt

Striploin

Roast

Blode Flathead Chuck Muscle 1 3 Chuck Tender

(a)

Steaks Cross Cut

Chuck Tender Roast

Steaks 2 Chuck Muscle 1

Steaks

Smoked Beef

Restructured Beef

Steaks Chuck Muscle 2 Breakfast Beef

Steaks

Bolar Steaks Restructured Beef Chuck Tender Chuck Muscle 4 Soft Jerky

Chuck Muscle 1 Frozen Free-flow Beef

Roast

Chuck Muscle 2

Chuck Muscle 3 Chuck Muscle 4

Pastrami

Cross Cut Restructured Beef

Roast

4

Steaks

Ready-Meal

Cube Roll Roast

Cross-cut

Bolar

Bolar

Head-to-Tail Restructured

Steaks

Shin Meat

Marinated or Restructured Steaks Tenderloin

Striploin Roast

Cube Roll

Brisket

Shin Meat On the Bone

Breakfast Beef Steaks Shin Meat Imitation Jellying Oxtail Beef

Steaks

Thin Skirt

Brachials

Crumbed Brisket Beaf Beef Sticks

Roast Tenderlion Roast

Flark Skirt

Brisket Steaks

Rump Eye Breading Steaks

Rump Eye

Thin Meat

Thin Meat Breaded & Crumbed

Food service Rotisserle

Steaks

Eye of Round Flat

Eye of Knuckle

Flank Skirt Steak

Thin & Thick Skirt Beef Floss

Flat

Roast Rump Eye

Corner Cut

Tritip Thin & Thick Skirt Beef Spread

Posterior Flat Anterior Steaks Steaks 2

Loose Cover Flank Skirt Beef Spread

Pastrami

Roast

Topside Eye Topside Cap Top Seam

Eye of Knuckle Steaks

Breakfast Beef

Eye of Round Beef Breakfast Strips Beef

Corner Cut

Boneless Beef Loose Cover Steaks

Ready Roast Tritip

Eye Roast

Eye Steaks

Steaks

Roast Ready

Eye of Knuckle Pre-cooked Roast

Topside Eye Cap Roast Retail Rotisserie

453

Chuck Muscle 3 Beef Floss Frozen Free-flow Beef Farouk, M.M., Kemp, R.M., Taukiri, K.R., 2002 www.mirinz.com

Fig. 18.1 Poster containing examples of restructured and convenience meats from New Zealand. (a) Adding value to beef. (b) Adding value to lamb.

18.3 Quality issues of restructured whole-tissue and convenience meat products Quality problems in restructured and convenience meats could be aesthetic (colour, appearance, exudates/cookouts in sliced packaged products, and

© Woodhead Publishing Limited, 2011

454

Processed meats

Lamb Bone Soup

Lamb Bones

These products were developed as part of a contract to Meat & Wool New Zealand funded by farmer levies.

Pre-cooked Roast Smoked

Lamb Bone Stock

Neck Bolor Pre-cooked Roast

Chops

Nibbles Corn-on the-cob

Roast

Nibbles

Full Shoulder BBQ-ready Lamb

Ready-meal

Pre-cooked Roast

Shank Plus Roast

Blode Roast Restructured Steaks

Free-flow Lamb

Steaks Shank Neck Plus

Bolar

Cube Roll

Cartlet Blade Roast

Tenderloin

Restructured

Full Shoulder Cartlet Meat Pack Tenderloin

Full Loin

Cube Roll Tail-on

Restructured

Oven Baked

Full Loin

Pre-cooked Eye of Round Roast

Brisket

Jerky Boneless Flap Roast Breakfast Bacon

Boneless Flap

Battered & Crumbed

Roast Brisket

Eye of Round Flat Battered & Crumbed

Knuckle Knuckle

Roast

Insides Top Rouund

Tunnel Boned Leg

Pre-cooked Roast

Rump Boneless “Breast”

Rotisserie Lamb

Deep Fried Steaks

Tunnel-boned Leg Roast

Insides Top Round Boneless “Breast”

Heel Pre-cooked Roast

Rump

Pre-cooked Patties

Toppings

Heel

Steaks

Restructured Steaks

Flat

BBQ-ready Free-flow Lamb Lamb Kebabs

Battered & Crumbed

Rotisserie Lamb

Trim Pre-cooked Roast

(b)

Ring Sausages

Pre-cooked Roast

Pre-cooked Meatballs

Fig. 18.1 Continued

overall visual appeal); oral (texture and tenderness); other sensory (flavour and aroma/odour); and convenience (loss of convenience) related. These quality problems are routinely checked by processors of restructured and convenience meats as part of their quality assurance programmes. The

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

455

product specifications monitored by National Meats New Zealand Ltd (http://www.nationalmeats.co.nz/) as part of their Cooked Restructured Whole-tissue Boneless Lamb Roll quality assurance is a good example of the type of issues pertaining to restructured meats that are monitored by processors (Table 18.1).

18.3.1

Aesthetics-related quality problems in restructured whole-tissue products Two of the most important factors affecting the point of purchase decision by consumers are the colour and appearance of meat products. Colourrelated problems are a major cause of reduced acceptability of restructured meats (Hunt and Kropf, 1987). Some of the factors that affect the colour of restructured meats include: • raw material condition, such as the oxidative-reductive state of the meat used in restructuring, meat pH and microbiological condition; • ingredients, such as the level of salt and its negative effect on colour or phosphates and their beneficial effect on colour; and • processing factors, such as boning time (hot versus cold), rigor state (pre- versus post-rigor), particle size reduction, blade tenderisation, temperature, pressure, and packaging (Hunt and Kropft, 1987). The use of non-uniform coloured meats that can be caused by mixing high and normal pH meats, meats aged for different periods of time, chilled and thawed meats or meat from muscles with predominantly white fibres and those with red can all cause colour and appearance problems in restructured meats. Misalignment of fibres during restructuring such as by restructuring meat with fibres aligned at different directions to the cut surface of steaks can also result in the reduced acceptability of cold-set raw restructured meat products. Colour problems in restructured meats may be related to the method of restructuring and the type of binder used. The colour and overall appearance of raw slices of cold-set beef rolls restructured using ActivaTM binding system were preferred over those restructured using an alginate binding system (Farouk et al., 2005b). Visual appearance issues have also been reported to arise from the poor dispersion of binders during restructuring (Esguerra, 1994; Mikkelsen and Esguerra, 1996). The authors restructured beef steaks and cubes using alginate and found that undissolved encapsulated acid appeared as small white spots in the steaks and poorly dispersed alginate appeared as red gel spots in raw chilled or thawed restructured cubes. The appearances of the steaks shown in Fig. 18.2 are a good example of an aesthetics-related problems. The cooked beef steak does not look natural owing to the cross-striations on the face of the steak caused by the alignment of muscle fibres parallel instead of perpendicular to the surface of the steak during restructuring.

© Woodhead Publishing Limited, 2011

456

Processed meats

Table 18.1 Excerpt from the National Meats NZ Limited Quality Assurance Product Specifications for Cooked Restructured Boneless Lamb Roll Organoleptic properties Property

Standard

Pink juice test (prior Absence of pink juice to re-heating in microwave) Appearance Cooked lamb – mid to dark reddy brown in colour (varying colour tone). There should be visible meat fibres present when sliced to 2.5 mm thickness. Visual lean >75% visual lean Sliceability Must be able to slice log to 2.5 mm thickness Aroma Strong lamb aroma Flavour Strong lamb flavour Texture Natural fibrous lamb texture Colour Mid to dark reddy brown in colour. Light white fat covering

Unacceptable Presence of pink juice Log broken, or excessive air pockets

>25% visual fat per slice face Meat falls apart during slicing/cutting (not correctly bound or too soft) Tainted aroma Off-flavours Rubbery/mushy (refer to texture measurement table) Pink/green

Customer texture measurement table Score

Definition

Graphic Description

1 2

Very tough Tough

3

Chewy

4 5

Slightly chewy Soft

6

Tender

7

Very tender

8

Extremely tender

9

Disintegrated

Impossible to chew (jaw aching) Very difficult to chew and break up after 6–8 chews Fibrous does not break up after 3–4 chews Initial bite fibrous but breaks up easily Easy to eat. Slices holds together well on fork Easy to eat, but lacks meat fibre texture Slices OK, handles into pack with minimum shreds with some tendency to break up after cooking Can be sliced but subsequent handling and cooking leads to excess shreds Falls completely apart on slicing mushy/sloppy texture

Note: This assessment is for the meat texture only. There will probably be a small amount of fat/ gristle present in the lamb meat which will perform differently. Any fat present should be soft to chew and there should be no gristle.

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

457

Fig. 18.2 The effect of wrong fibre alignment during restructuring on sliced beef steak appearance.

Restructured meats with visible connective tissues, gristle or large fat particles will also be rejected by consumers. Colour and appearance problems are more important in cold-set restructured products that are often sold uncooked and/or chilled relative to hot-set restructured products as they are likely to be sold in cooked or frozen form. This is exemplified by the results of a study by Farouk and Swan (1997) in which a consumer panel could not differentiate between the colours of cooked hot-set restructured roast beef prepared from non-uniformed coloured meats including pre-rigor, post-rigor, grass- and grainfinished beef. Farouk et al. (2005a) determined the effect of fibre alignment on the appearance of restructured steaks and found that raw restructured beef steaks with fibres aligned parallel to the cut steak surface were ranked highest in acceptability by a consumer panel compared with steaks with fibres aligned perpendicular or mixed. The panellists indicated their choice was influenced by the colour and appearance of the cut steak surface; they found the most preferred steaks to be the most uniform in appearance, most consistent in colour, and the ones that looked the most natural; and the least preferred ones to have mottled appearance, chunky look and more obviously processed appearance. When the same steaks were cooked, the ones with fibres running parallel to their cut surface were ranked lowest compared with the perpendicular and mixed ones. The reason for the change in the visual appeal of the parallel aligned steaks from being the highest ranked in the raw state to the lowest in the cooked state was because in the raw state, colour had more influence on the decision of the panellists, as it was more difficult to see the direction of the fibres in relation to the steak surface; the effect of the fibre alignment became more obvious after cooking and the parallel aligned steaks lost their natural-look appeal.

© Woodhead Publishing Limited, 2011

458

Processed meats

18.3.2

Aesthetics-related quality problems in convenience whole-tissue meats Some of the important colour and appearance problems associated with pre-cooked uncured or cured whole-tissue convenience meats include the pink defect in uncured meat, colour fading in cured meat, and iridescence in both cured and uncured meats. Other appearance problems include exudates (drip and cookouts) in pre-cooked pre-sliced package meat products. Pink defect in cooked meats Pink/reddish defect in uncured meat is a condition where well-cooked meat still retains a pink or reddish uncooked colour or develops pinkish coloration with storage after cooking. Reddish or pink colour in fully cooked meat will cause consumers to reject the meat as undercooked, or subject the meat to further cooking, resulting in meat of poor eating quality (King and Whyte, 2006). Fully cooked meat is off-white, grey or brown, depending on the type of muscle. The change in meat colour on cooking from the three possible states of the meat colour pigment myoglobin (purplish red deoxymyoglobin; cherry red oxymyoglobin; brownish red metmyoglobin) to the off-white or grey brown is due to the denaturation of the globin in the pigment. The chemistry of cooked meat colour has been summarised by King and Whyte (2006) as follows: as globin is denatured, metmyoglobin forms the brown globin haemichromogen, also known as ferrihaemochrome; the other myoglobins are denatured to the red globin haemochromogen, also known as ferrohaemochrome; the latter is readily oxidised to the former, so ferrihaemochrome is present in larger amounts in cooked meats. The ultimate colour of the cooked meat depends on the extent of ferrihaemochrome formation, which in turn depends on the initial proportion of the myoglobins, and the final concentration of undenatured oxy- or deoxymyoglobin. Ferrihaemochrome formation from myoglobin during cooking is affected by ultimate meat pH. The higher the ultimate pH the less myoglobin is denatured and thus the lower the amount of ferrihaemochrome present and so the cooked meat appears reddish or pink even at high internal temperatures (Mendenhall, 1989). Other factors that can cause pink colour in cooked meats include the exposure of myoglobin to nitric oxide and the formation of nitrosylhaemochrome (similar colour to cured meats). Nitric oxide can unexpectedly enter the meat through nitrites, exhaust fumes, oven gases, or simply low concentrations of sodium nitrite present on improperly sanitised processing equipment (Cornforth et al., 1991; Van Laack et al., 1996). Cured colour fading Consumers expect the colour of cured meats such as hams, corned beef or pastrami to be pink. The pink colour is formed when nitrites react with the

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

459

meat colour pigment myoglobin to produce a pink colour pigment nitrosohaemochromogen (Pearson and Gillett, 1999). During retail display in deli counters in supermarkets or butcheries, cured meats are often sliced and displayed under light and atmospheric oxygen, causing the pink colour to fade to a brown grey colour and resulting in loss of consumer appeal (Andersen et al., 1988; Møller et al., 2002). The fading of cured meat colour occurs in two steps including the dissociation of nitric oxide from haem groups catalysed by light, followed by the oxidation of nitric oxide and haem groups by oxygen (Hedrick et al., 1994). The same authors (Hedrick et al., 1994) reported that the fading process requires both light and oxygen, and if no oxygen is present, the nitric oxide that dissociated from the haem groups will not be oxidised, and it can then recombine with the haem. According to Larsen et al. (2006) even small amounts of oxygen in the headspace of a package will cause pink colour to fade within 6 to 8 hours when exposed to the lighting conditions often found in refrigerated display cabinets. Other factors that affect the rate of colour fading of cured meats include the level of nitrite and the type of curing agents or additives used during curing, the time of exposure to light or oxygen post-slicing, the oxygen transmission rate of the packaging material, the residual oxygen after packaging and the gas to product volume ratio (Andersen et al., 1988; Farouk et al., 1997; Larsen et al., 2006). Iridescence Another colour problem associated with cured or pre-cooked whole-tissue convenience meats is that of iridescence. Iridescence is an abnormal colour that resembles a bright rainbow or rainbow-like colour array which consumers find visually unappealing and may falsely associate with old or unwholesome meat products (Lawrence et al., 2002). The dominant colour in iridescent meat is green, followed by red and orange (Swatland, 1988; Lawrence et al., 2002). Figure 18.3 shows an example of iridescence in cured processed meat. Swatland (1984, 1988) reported that iridescence is caused by the microstructural diffraction of light by muscle fibres which occur at the subsurface layers of the muscle where reflected light may be partly polarised. The intensity and extent of iridescence in meat are affected by a number of factors including the age and sex of the animal from which the meat was obtained, muscle type, meat pH, meat moisture content or level of hydration, type of additives used during processing, processing methods such as the use of blade tenderisation or high pressure, sharpness of slicers or the smoothness of the meat slice surface, and slice surface viewing angle (Swatland, 1988; Lawrence et al., 2002; Obuz and Kropf, 2002; NunezGonzalez et al., 2005; Fulladosa et al., 2009). Exudates in pre-packaged pre-sliced meats Consumers expect pre-packaged, pre-cooked meats to look fresh and natural, and detest the presence of drip, cookouts and all forms of exudates

© Woodhead Publishing Limited, 2011

460

Processed meats

Fig. 18.3 Iridescence in sliced beef pastarma from semitendinosus muscle.

around the packaged products. This dislike of the presence of cookouts could be likened to the way consumers view drip and exudates in traypackaged raw meat on display at retail counters in supermarkets. A number of factors could contribute to the problem of exudates in pre-packaged, pre-sliced meats including poor water and fat-binding capacity of the raw meat, high brine acidity, overextension of raw meats over their green weights, less than optimum tumbling time and temperature of extended meats, the type of binding systems/binders used in restructuring, and finally purge due to vacuum pressure applied during packaging.

18.3.3 Texture/tenderness-related quality problems Restructuring is done to achieve an imitation product that possesses the attributes of the real McCoy. Terms such as rubbery, spongy, soft, mushy, crumbly, chewy, loose and aerated are used by consumers to describe texture problems in restructured meats (Mikkelsen and Esguerra, 1996; Flores et al., 2007). According to Berry (1987), texture problems of restructured meats may be related to excessive or insufficient bind, lack of uniformity of texture, excessive connective tissue, distortion of cooked product, excessive crust formation, layering or formation of pockets inside the product during cooking. Sheard (2002) suggested three factors might affect the eating quality of restructured meats: the nature of the meat pieces (such as their size, shape, surface morphology and fibre direction), orientation and composition; the amount and composition of the surface protein matrix;

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

461

and the relative proportion of the meat pieces to the surface matrix. The texture of cooked restructured meat is also affected by the muscle fibre alignment with respect to the adhesive junction; the degree of adhesion between meat pieces and; the size of the meat pieces in the restructured meat (Purslow et al., 1987; Lewis and Purslow, 1990; Savage et al., 1990). Boles and Shand (1998) determined the effect of particle size on the acceptance of restructured beef steaks produced using alginate binding systems and found that particle size had no effect on the consumer acceptability of the texture of the restructured steaks. Flores et al. (2007) found no effect of binders on the consumer acceptability of the texture of pork restructured with ActivaTM, FibrimexTM or phosphates. However, Esguerra (1994) reported that alginate bound steaks were more tender than Pearl F bound steaks. Farouk et al. (2005b) also reported that consumers preferred the tenderness of beef rolls restructured using alginate binding system relative to ActivaTM bound ones. Previous studies indicated that muscle fibre alignment in whole-tissue steaks from different species of animals affected the texture of the steaks measured objectively or subjectively (Guenther, 1989; Poste et al., 1993; Otremba et al., 1999). Results of these studies show that cooked intact whole-tissue meat samples sheared parallel to the direction of meat fibre or masticated with the grain were more tender than those sheared in perpendicular direction to the fibre direction or masticated across the grain. Farouk et al. (2005a) subjected beef steaks that were coldset restructured with the meat fibres aligned parallel, perpendicular or an equal mixture of parallel and perpendicular (mixed) in relation to the cut steak surface to consumer preference test and found that consumers preferred the texture and tenderness of the steaks with fibres running perpendicular or an equal mixture of parallel and perpendicular to the face of the steaks compared with those with fibres running parallel only. The steaks with fibres running parallel also ranked significantly lower than the other two products in overall eating quality.

18.3.4 Flavour and odour-related quality problems One of the major causes of deterioration in the flavour of restructured and convenience meats is lipid oxidation. The presence of high levels of oxygen around and/or in packaged meat products will facilitate lipid oxidation and the development of off-flavours and off-odours often characterised as stale, rancid, musty or barnyard. Another term commonly used to denote oxidation in cooked meats is warmed-over flavour (WOF). WOF develops rapidly during refrigerated or frozen storage of pre-cooked, partially cooked meat, raw meat products or meats in which the membranes are broken down such as in restructured and convenience meats, or meat packaged in high oxygen modified atmosphere packaging (Pearson and Gray, 1983; Love, 1988; Clausen, 2004). Lipid oxidation and WOF development in restructured meats are influenced by the raw materials used in restructuring, reduction

© Woodhead Publishing Limited, 2011

462

Processed meats

in particle size, and cooking and/or heating of the product (Gray and Pearson, 1987). Undesirable flavours and odours can also arise due to the ingredients and additives used in restructuring or the formulation of convenience meats. Whey protein, wheat gluten, soy protein isolates, carrageenan and tenderising enzymes in meat restructuring have been reported to affect finished product flavour (Miller et al., 1988; Chen and Trout, 1991; Demos et al., 1994). Fraser et al. (1993) used a variety of hot-set binders in restructuring lamb roast and found that undesirable flavours increased with increased storage time. The presence of liver-taste off-flavour in restructured beef and pork steaks have been associated with the use of cold-set binders such as ActivaTM and FibrimexTM (Esguerra, 1994; Flores et al., 2007). The presence of high numbers of spoilage microorganisms will lead to the development of off-odours in chilled restructured meat products before any flavour changes are detected by the consumer (Kotula et al., 1987).

18.3.5 Quality problems related to loss of convenience Convenience meat products can be rendered less convenient in many ways including: • • • • • • •

difficult to open packages; poor sliced product separation; uneven reheating of frozen or chilled products; difficulty with handling re-heated products; burns due to captive steam; spillage/splatters; and difficulty in re-packaging left-overs.

The ease of opening a package is an important consideration for many customers when it comes to buying convenience foods. The majority of portion-controlled convenience meat products are packaged in flexible films and vacuum sealed; the fully cooked entrées are packaged in flexible film in which the product is cooked in and then surrounded by other secondary packaging (Eilert, 2005). Such packages can be tough to open, requiring the use of slitting or puncturing implements to accomplish. The packaged products also tend to stick together due to vacuum pressure making it difficult to separate the individual portions. All these issues can result in loss of convenience and product appeal. According to Parlin (2004) consumers want to avoid slitting or puncturing plastic covers and other activities that require time, implements and decisions. The ease of opening a package has added importance for the elderly and those with hand mobility issues. Those aged over 65 represent the fastest growing consumer group in modern Western societies (Saba et al., 2008) and tough to open packages are a problem for this demographic group.

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

463

Packaging is a key attribute for the convenience of heat-and-eat foods because the package acts as a cooking utensil, serving dish and in some cases a dinner plate (Swientek, 2008). For the meat component of heat-andeat foods, the convenience provided by the package can be lost when: • the contents of the package are not able to be reheated properly at the first attempt, leaving cold or partly frozen spots that often get overheated with repeated reheating, resulting in additional delays in product table-readiness; • a consumer gets burnt from handling hot and steamy reheated packages, which can also cause spillage and splatters; and • a consumer spends time figuring out how to re-package left-overs, since many consumers use only a portion of their heat-and-eat product at a single meal (Wray, 2008).

18.4 Improving product quality There are a number of ways to improve the quality of restructured and convenience meat products. Most improvements are consumer driven and enabled by technology advancement. Any changes made to a product formulation or process must be balanced with the need to maintain the overall quality of the final product and should not just improve some attributes at the expense of the others. Factors such as cost, potential risk to health, environmental effect and even carbon footprint should be considered while deciding on ways to improve product quality.

18.4.1 Improving visual appeal For whole-tissue restructured steaks to have an appearance that closely resembles that of a real steak, the muscle fibres/fibre bundles in the restructured steaks should be aligned (Guenther, 1989) and the colour and other visual attributes of the meat should be as uniform as possible. To achieve this, the meat fibres/fibre bundles should be aligned so that the fibres are perpendicular to the cut steak surface. This is very important as the aim of the restructuring is to produce restructured steaks that imitate steaks from the more expensive cuts such as the cuberoll, striploin or tenderloin, and especially when the consumer will have the opportunity to view the cooked steak before consumption. The use of larger pieces of meat or intact muscles will improve the appearance of restructured meats relative to the use of smaller sized meat pieces. To minimise distortion of cooked whole-tissue restructured products, muscles skinned of surface connective tissue should be used or high connective tissue cuts should be tenderised using a mechanical tenderiser before restructuring. The appearance of raw or pre-cooked restructured meats can be improved by coating, battering, breading, crumbing or encrusting using ingredient

© Woodhead Publishing Limited, 2011

464

Processed meats

blends tailored to give a certain finish to the product. Lazar (2007) discussed some recent developments regarding the battering and breading of meat and poultry products and gave examples of KFC and battered chicken fried steaks as having an appearance that is pleasing to consumers. Similar products can be developed from restructured whole-tissue beef, lamb, chevon and venison to improve the appearance and colour of such products. The range of available coating ingredients that can improve colour and appearance are broad, Kerry Ingredients alone has more than 30 pre-dusts, 100 batters and 12 crumb colours (Anon, 2006b). The problem of pink discoloration in cooked uncured restructured and convenience meats can be reduced by using meat of normal pH or cooking high pH meat at higher temperature if the phenomenon is related to high pH and the presence of undenatured colour pigments (Cornforth et al., 1991). Moiseev and Cornforth (1999) compared the effect of food-grade oxidants and browning agents including glucose, caramel colour, calcium peroxide and lactic acid on reducing pink discoloration in high pH beef and found the use of lactic acid to be the most effective but with tangy off-flavour development; caramel and calcium peroxide were effective too but had negative impact on product quality. If pink discoloration is due to the formation of nitrosylhaemochrome formed by the reaction of colour pigments with nitrous oxide, then the source of the gas should be determined and eliminated. Good manufacturing practice that puts effort into reducing or eliminating external contamination of nitrate or nitrite will reduce the problem considerably (Holownia et al., 2003). Sammel et al. (2007) tested constituents of whey protein concentrate for their ability to reduce the naturally occurring pink colour defect induced by sodium nitrite and found that calcium chloride was the only constituent that consistently reduced pink colour in ground turkey. Colour fading in cured meats could be reduced through the use of proper packaging that eliminates or substantially reduces the contact of cured products with oxygen or light. Opaque vacuum packaging will increase the colour stability of cured meats (Cornforth and Jayasingh, 2004). Larsen et al. (2006) determined the effect of packages with different oxygen transmission rates, gas-to-product-volume ratios and various levels of residual nitrogen and suggested a residual oxygen level of below 0.15% immediately after packaging combined with low oxygen transmission rate (0.4 mL O2/package × 24 h) and a gas-to-product-volume ratio of 2.6 were the optimum condition for maintaining the cured colour of ham. Different adjuncts including alpha tocopherol, sodium tripolyphosphate, tetrasodium pyrophosphate, ascorbic acid, citric acid and sodium erythorbate have been used to stabilise the colour of cooked processed meat products (Molins et al., 1987; Okayama et al., 1987; Manu-Tawiah et al., 1991; Arnold et al., 1992, 1993). Farouk et al. (1997) determined the effect of alpha tocopherol, sodium tripolyphosphate, ascorbic acid, copper gluconate, sodium sulphite, sodium erythorbate, citric acid and tetrasodium pyrophosphate on the colour stability of bologna

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

465

and found that the combination of ascorbic acid and copper gluconate reduced the rate of colour fading in this product significantly over the other adjuncts. A number of alternative cures or natural sources of nitrates and nitrites have been reported, such as vegetable juice powder, celery juice powder, beet juice powder, celery juice concentrate and carrot juice concentrate (Sindelar et al., 2007; O’Donnell, 2009); however, cured colour fading in products processed using these natural sources of nitrites have not been determined in previous studies to ascertain if the problem could be mitigated by using the natural cures. Zarringhalami et al. (2009) replaced nitrite with annatto as a colour additive in sausage at 0, 20, 40, 60 and 80% and found that replacing nitrite by 60% with annatto resulted in sausages with the best and most stable colour with no significant effect on the microbial or sensory properties of the sausages compared to controls produced using 100% nitrite. Iridescence in restructured and convenience whole-tissue products can be significantly reduced by the choice of muscle to be used in the products. Kukowski et al. (2004) compared a number of muscles including m. biceps femoris, m. gluteus medius, m. longissimus lumborum, psoas major, m. rectus femoris, m. semimembranosus, m. semitendinosus, and m. tensor fasciae latae for occurrence of iridescence and found that the occurrence was higher in m. semitendinosus (94%) compared with the other muscles; m. semimembranosus with the second highest frequency of occurrence had iridescence only 34% of the time. For this reason and because other studies also found m. semitendinosus to have the highest occurrence of iridescence (Lawrence et al., 2002; Nunez-Gonzalez et al., 2005), the problem could be reduced by not using the m. semitendinosus muscle. Iridescence intensity and the area of iridescence in meat product can also be reduced using physical methods including surface roughening through the use of textured-face meat-slicing blade during the slicing of pre-cooked cured beef or the blade tenderisation of meat prior to cooking (Lawrence et al., 2002; Obuz and Kropf, 2002). The problem of exudates in pre-cooked pre-packaged sliced meats can be reduced by the following: • Using meats with high water and fat binding capacity such as properly processed, aged and chilled/frozen, high ultimate pH, or pre-rigor salted meats. • Optimising the extension of meats, ingredients, time/temperature control during tumbling and mixing. • The use of packages and package environment requiring minimum or no vacuum. There are many ingredients of chemical, plant and animal origin including blends of phosphates, starches, hydrocolloids, flours, cereals commercially available for binding water and fat in processed meats that could be used to reduce exudates in packages. Pszczola (2010) recently reviewed some of

© Woodhead Publishing Limited, 2011

466

Processed meats

the latest commercial offerings of binders including LuraLean® M. from AHD International marketed as a natural meat binder that creates a heatstable gel which gives sliced meat an increased yield with less drip and cookout in packages; a non-allergen meat and poultry binder from BindMax Proteins that can be used to replace other binding ingredients such as soy, milk and sodium phosphate; and Actobind, an ingredient system from Advanced Food Systems that can partially or completely replace sodium phosphate in injected or tumbled cooked meats.

18.4.2 Improving oral appeal Berry et al. (1988) restructured beef steaks to have extra-high, high or low levels of connective tissue and subjected the steaks to consumer sensory analysis. They found that the texture and toughness of extra high connective tissue steaks was undesirable. Therefore, the texture and tenderness of restructured whole-tissue meats can be improved by reducing the amount of connective tissue or gristle in the meat to be restructured. The texture and tenderness of restructured meats can also be improved by aligning the muscle fibres or fibre bundles to be perpendicular or a mixture of 50 : 50 perpendicular and parallel fibres relative to the face of the steak when sliced (Farouk et al., 2005a). The use of enhanced meat in hot-set restructuring will improve tenderness and juiciness of the final product (Lennon et al., 2010). For instance, intact US choice and select strip loins were injected with up to 15% solution containing phosphate, lactate and chlorides, and then the steaks were assessed by a trained panel and were found to have improved the tenderness, juiciness, and cooked beef flavor relative to control (Vote et al., 2000); and Robins et al. (2003) injected strip loins and rounds up to 10% with a solution containing sodium tripolyphosphates and sodium chloride, then evaluated the steaks using a consumer panel and found that the injected steaks were more acceptable than the controls. Mechanical tenderisation of cuts prior to restructuring will also improve the oral appeal of restructured and convenience meats. Lennon et al. (2010) compared restructured beef steaks produced using meat mechanically tenderised by blade or needle tenderisation or enhanced by brine injection + vacuum-pulsing with control steaks (no mechanical tenderisation) and found that the three tenderisation methods improved the mechanical and sensory tenderness of the restructured steaks relative to controls. Marinades and rubs can also be used to tenderise meats prior to hot-set restructuring or used on cold-set ones in order to improve the texture of the products (Jones, 2004). The addition of 3 or 8% water in restructured beef cubes formulation improved the tenderness and texture of the cubes significantly over that of control with no added water (Mikkelsen and Esguerra, 1996). A marinade developed by Symrise is reported to improve the tenderness attributes of meat products by giving less expensive cuts the same eating qualities as more expensive cuts (Pszczola, 2010).

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

467

The use of coatings can improve the texture of meat products because many consumers identify with the colour and texture of coated, battered, breaded or encrusted meats (Pczczola, 2002). Crunchy textures are very popular with consumers; thus, fried coated restructured steaks can be produced to improve the texture of such products. Recent developments such as the Newly Crisp Process developed by Newly Weds Foods and the batter ingredient formulations by McCormick enables processors to produce oven or microwave processed coated products that have the same crunch and texture normally associated with products that have been fried albeit with substantially less oil and fewer calories (Pellegrini, 2008).

18.4.3 Improving flavour and aroma appeal The control of flavour deterioration due to lipid oxidation in restructured and convenience meats can be accomplished to varying degrees of success by using natural and synthetic antioxidants, chemical compounds and chelating agents, as well as by the exclusion of oxygen. The following were shown to inhibit or retard oxidation: EDTA and ascorbic acid (Liu and Watts, 1970); 156 ppm nitrite, 0.5% tripolyphosphate and 2% ethylenediaminetetraacetic acid (EDTA) (Igene and Pearson, 1979); extract of egg plant tissue, peels of yellow onions (Younathan et al., 1980); catechol, EDTA, diethylenetriaminepentaacetic acid (DTPA), sodium polyphosphate, sodium tripolyphosphate (Shahidi et al., 1986); rice bran oil (Kim et al., 2000); Grape seed extract and pine bark extract (Ahn et al., 2002; Rojas and Brewer, 2007); Chinese 5-spice ingredients composed of cinnamon, cloves, fennel, pepper and star anise (Dwivedi et al., 2006); and the aqueous extract of rosemary, sage and thyme (Mielnic et al., 2008). Lipid oxidation-related flavour and odour problems can be reduced through effective packaging that excludes oxygen in the environment of the meat product. Vacuum packaging, gas flushing and oxygen-absorbing systems have been used effectively to reduce oxygen in the headspace of packaged products in order to retard lipid oxidation and microbial growth and their associated flavour and odour problems (Coma, 2008; Gomes et al., 2009). Chr. Hansen’s Bactoferm Rubis is a new meat culture that is reported to solve the problem of oxidation in pre-packaged meats without affecting the sensory attributes of the packaged product by simply consuming oxygen as part of the culture’s metabolism, thereby eliminating the need for antioxidants or synthetic oxygen scavengers (Pszczola, 2010). A number of flavourings have been introduced that could be used to maintain and enhance desirable flavours or mask unfavourable ones in restructured and convenience meats. Jimenez (1999) reported that yeast extracts, vegetable protein hydrolysates, monosodium glutamate and 5′ nucleotides were the substances most frequently used in the food industry to provide or enhance meat flavours. Examples of flavour enhancers and masking agents for meat products include:

© Woodhead Publishing Limited, 2011

468

Processed meats

• Wix-Fresh, a natural ingredient that eliminates WOF from Wixon, Inc.; • NFE-S from Kikkoman International Inc., made from fermented wheat protein to give a balanced, brothy umami flavour and to act as a replacement for hydrolysed vegetable proteins; • yeast extract products including Beef and Roasted Beef Flavorin from Levapan; and • a new range of natural beef flavours for the European palates by International Flavours & Fragrances including Rare, Marrow Bone, Boiled, Roast, Grilled, and Stewed Beef considered by the processors as the truest benchmarks of the best-loved beef profiles (Pszczola, 2004, 2010). Create Flavours a UK flavour firm recently launched a range of natural herbs designed to impart freshness into ready meals and meat products (Hughes, 2009). Other flavourings earlier reported include: • ClassicRoast by Kraft Food Ingredients that delivers an authentic, slow roasted flavour profile suitable for use in beef and pork; • Robust EliteR a beef flavor by Griffith Laboratory; flavours characteristic of grill and outdoor barbecue including spicy grill, chargrill, hibachi with true ash, gas grill and wood smoke flavours; • RoastinTM by Red Arrow Products Co. designed to impart savory roasted notes; • Kerry Ingredients’ specially formulated beef flavour composed of garlic, rosemary, thyme, savory and creamed butter flavourings; • a beef flavour marketed under the brand name FlavorleanTM by Flavex Protein Ingredient; and • Proliant Inc., Premium Beef Extract Flavour and Premium Beef Flavour Base (Pszczola, 2002). Reverte et al. (2003) and more recently Stika et al. (2008) added propyl gallate and a beef flavouring in the formulation of restructured beef steaks from forage- and grain-fed cattle and matured cows respectively and demonstrated that the strong grassy flavour of forage-finished beef steaks detected by sensory panel was masked by the beef flavouring agent, thereby improving the acceptance of the restructured steaks by consumers. The use of propyl gallate retarded lipid oxidation and the development of rancid flavours in restructured steaks from matured cows, but was unable to overcome the low acceptability of steaks with inherent off-flavours and the use of propyl gallate in combination with the beef flavouring agent helped mask off-flavours associated with forage-fed beef. Lamb and goat roasts treated with prime rib spice were found by both trained and consumer panels to have less species-related flavours and WOF compared to control roasts (Hilton et al., 2006; Kellermeier et al., 2006). Young and Cummings (2008) reduced sheepy, rancid and barnyard flavours in sheepmeat through the use of the 5-carbon sugar xylose. Liquid smoke can be used to control lipid oxidation and impart a desirable flavour to restructured and convenience

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

469

meats; a survey by the National Provisioner (Robinson, 1998) indicates smoke flavour is one of the favourite flavours for both consumer and food processors. Coatings, crumbs, breadings, batters and glazes can be combined with seasonings and antioxidants to improve the flavour of restructured and convenience meats and to prevent the development of WOF in these products (Lazar, 2007; Pellegrini, 2008).

18.4.4 Improving convenience The convenience of restructured and prepared meats can be improved if the current products that are pre-cooked and sliced for portion control are contained in packages that: • represent smaller portions to meet the requirements of single consumers; • prevent the products from sticking together; • are easy to open; • are re-sealable once opened for the safe storage of leftovers; and • allow items that require reheating to be reheated quickly and evenly while packaged using conventional ovens or microwaves without the need to transfer the content of the package to ovenable or microwaveable containers. Pre-cooked sliced meat products can be made more convenient by producing and packaging smaller portions to meet the requirements of single consumers, and the older and younger segments of the population (Swan et al., 1997). Smaller portions are the trend according to a recent article on what America eats (Sloan, 2008), as best exemplified by Sadler’s Dinner for Two Pit-Smoked Beef Brisket designed to accommodate one- and twoperson households (Ashman et al., 2010). In terms of slice separation, modified atmosphere packaging made up of microwaveable trays which are lidded with barrier films that use low oxygen gas mixtures (70% N2 and 30% CO2) are now being used to accommodate easier separation of sliced products by the consumer (Eilert, 2005; Belcher, 2006). Multivac (Anon, 2005) introduced a Serve Box packaging for deli and luncheon meats that can add convenience to these products; the packaging consists of a tableready rigid plastic tray, sealed with a transparent plastic dome lid capable of accommodating repeated openings and closings and can be gas flushed for modified atmosphere applications. The use of active packaging can add convenience by eliminating the need to vacuum or gas flush for modified atmosphere where slice separation in pre-cooked meats is desired (Coma, 2008). Gomes et al. (2009) tested an active package pouch made of laminates that incorporates an iron-based oxygen absorber (ABSO2RB®) for its ability to extend the shelf-life of a fatty food and found that the active package prolonged the shelf-life of products relative to regular hot-filled meal ready-to-eat pouches that served

© Woodhead Publishing Limited, 2011

470

Processed meats

as controls. Such pouches could be used to eliminate the need for vacuum or modified atmosphere package products to improve sliceability. For canned products such as corned beef and similar products, a microwaveable steel-can recently introduced by Ball Corporation (Anon, 2007) could improve the convenience of these products; the microwaveable steel can is made of an EZOpen end, a multilayer polypropylene plastic end that is joined to a steel can body. According to the manufacturers of this can, the plastic end allows microwave energy to pass through the product, heating it quickly and evenly and because the package heats from inside out, the package walls stay much cooler than those of plastic microwaveable bowls. For meat components in heat-and-eat or ready-to-eat meals, convenience can be improved if packaging will allow such products to be reheated without the need to handle hot packages. Cryovac Sealed Air Corporation introduced Simple StepsR heat-and-serve packaging (Parlin, 2004) that eliminates the need to puncture ventilation holes in the package before heating. The package features a ‘stay cool’ side handle which reduces the risk of burns or spills as the reheated package is removed from the microwave. O’Grady and Kerry (2008) reported that the Kepak Group of Ireland, a leading producer of ‘Heat n Serve’ convenience meats marketed under the Global Cuisine Brand, uses a vacuum skin packaging technology (Cryovac Darfresh®) that enables the products to be cooked, shipped, stored, displayed, sold, reheated and served in the same package. The packages used in Kepak’s Global Cuisine line (http://www.kepak.com/web/ guest/meat/hs) of convenience meats including Ready Roast, Tender Cook and Summer Eating do not need to be vented before reheating and feature an easy-open top for consumers to peel away for serving. Another packaging innovation that could improve the convenience of meats in ready-to-eat meals is the self-venting stand-up pouch steam-andserve packaging technology introduced by Curwood Inc. USA (Anon, 2006c). The packaging features a controlled-peel system, cool-zone handgrips and the ability to serve from the pouch, thereby avoiding cooking splatters, messy handling and burns from captive steam. Brody et al. (2008) reported a recent packaging development that enables hot- and cold-serve items of a multi-component meal to be heated together without the need to separate such items; the product (CuliDish) uses varying levels of aluminium within a tray, which allows items such as meats to be reheated in the microwave at the same time with items such as salads that do not require reheating.

18.5 Future trends As the market continues to get more competitive and consumer and food service operations demand easy-to-prepare, consistent, higher-quality,

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

471

flavourful meat products, there will be room for restructured products to grow (McGuire, 2009). Technology to automate or mechanise the alignment of muscle fibres during restructuring to achieve a more natural looking product should be developed to take advantage of the growing trend in the demand for such products. Additionally, with the growing number of new products that use restructured meats as ingredients, and as the forms of restructured products continue to evolve, more research effort should be directed towards developing methods of evaluating the new products that are being produced in order to optimise their quality. Current trends indicate consumers are demanding more natural products with no additives of any kind where possible. Natural ingredients for solving the following problems associated with restructured and convenience meats should continue to be investigated: • ingredients to prevent pinking in fully cooked uncured meats, iridescence in raw and cooked meats and colour fading of cured meats; • brines/cures to produce the characteristic cured colour in nitrate- and nitrite-free convenience meats and to determine the role of such cures in preventing colour fading; and • antioxidants to prevent lipid oxidation and WOF in meats. The consumer demand for convenience is continuously growing and should be met and anticipated by meat processors. Only continuous advances in packaging and processing technologies will enable this demand to be met. Tremendous advances made in the area of meat packaging have been reported (Eilert, 2005; Belcher, 2006; Kerry et al., 2006; Brody et al., 2008), which should be commercialised and adopted in order to improve the convenience of further processed meats in the areas of product stability, portion control, reduced wastage, ease of package opening, slice separation, and handling during reheating. Convenience-specific or personalised convenience such as products for children and the elderly will increase; innovation in formulation, processing and packaging to meet these requirements in restructured and convenience meats need to happen. A paradigm shift in the nutritional design of foods has been recently proposed; moving from the traditional way in which foods are put together to achieve a balanced diet or nutrient density to one in which foods are combined for the enhanced delivery and functionality of a target nutrient (Farouk et al., 2009). Knowledge from the new paradigm can be used to co-restructure meat or to produce convenience meats containing other components that will enhance the delivery or functionality of a target meat nutrient for targeted consumers. Application of the new paradigm in restructured and convenience meats processing should be encouraged. Processing to meet the needs of target populations or demographic groups such as ethnic groups, the elderly, and people with dietary or religious requirements such as producing gluten-free, halal and kosher

© Woodhead Publishing Limited, 2011

472

Processed meats

restructured and convenience meats will continue to grow as processors become more aware of the potential of such market segments.

18.6 Sources of further information and advice Excellent literature is available on the methods of restructuring meats and the type of products produced (Pearson and Dutson, 1987; Pearson and Gillett, 1999; Sheard, 2002). The websites of some of the companies associated with the products reviewed in this chapter are good sources of information on these and related products. Food Technology, a publication of the Institute of Food Technologists (IFT) www.ift.org, provides regular concise summaries of the 10 top food trends, including the advancement in packaging and convenience foods. Popular journals, some of which have been referenced in this chapter, are also excellent sources of product development trends and new product offerings from the food industry.

18.7 References and further reading ahn, j., grun, i.u., fernando, l.n. (2002). Antioxidant properties of natural plant extracts containing polyphenolic compounds in cooked ground beef. Journal of Food Science 67: 1364–1369. andersen, h.j., bertelsen, g., boegh-sorensen, l., shek, c.k., skibsted, l.h. (1988). Effect of light and packaging conditions on the colour stability of sliced ham. Meat Science 22: 283–292. anon. (2004). Natural pork ribs. Meat Processing, March: 53. anon. (2005). Reclosable rigid packaging for sliced cheeses, luncheon meats. Food Engineering, August: 19. anon. (2006a). Karoocuisine targets UK. Meat Trades, December 8: 14. anon. (2006b). Thousand of options from Kerry. Australian Meat News, September: 17. anon. (2006c). Standup Pouch. Meat & Poultry, December: 72. anon. (2007). Microwavable steel can. Food Engineering, January: 22. anzco. (2009). ANZCO Foods Limited. www.anzcofoods.com arnold, r.n., scheller, k.k., arp, s.c., williams, s.n., buege,d.r., schaefer, d.m. (1992). Effects of long- or short-term feeding of u-tocopheryl acetate to Holstein and crossbred beef steers on performance, carcass characteristics and beef color stability. Journal of Animal Science 70: 3055–3065. arnold, r.n., arp, s.c., scheller, k.k., williams, s.n., schaefer, d.m. (1993). Tissue equilibration and subcellular distribution of vitamin E relative to myoglobin and lipid oxidation in displayed beef. Journal of Animal Science 71: 105–118. ashman, h., beckley, j., leach, c. (2010). Dinner built for two. Meatingplace, April: 17–18. bedington, e. (2002). Microwaveable meat launched. Grocer, November 2: 48. belcher, j.n. (2006). Industrial packaging developments for the global meat market. Meat Science 74: 143–148. berry, b.w. (1987). Texture in restructured meats. In Advances in Meat Research, Vol 3. Restructured Meat and Poultry Products, edited by Pearson, A.M. and Dutson, T.R., pp. 271–306. New York: Van Nostrand Reinhold Company.

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

473

berry, b.w., smith, j.j., secrist, j.l., douglass, l.a. (1988). Consumer response to restructured beef steaks processed to have varying levels of connective tissue. Journal of Food Quality 11: 15–25. boles, j.a., shand, p.j. (1998). Effect of comminution method and raw binder system in restructured beef. Meat Science 49(3): 297–307. brody, l.a., bugusu, b., han, j.h., sand, c.k., mchugh, t.h. (2008). Innovative food packaging solutions. Journal of Food Science 73(8): R107–R116. buckley, m., cowan, c., mccarthy, m. (2007). The convenience food market in great Britain: convenience food lifestyle (CFL) segments. Appetite 49: 600–617. chen, c.m., trout, g.r. (1991). Sensory, instrumental texture profile and cooking properties of restructured beef steaks made with various binders. Journal of Food Science 56(6): 1457–1460. clausen, i. (2004). Sensory evaluation of beef loin steaks stored in different atmospheres. Proceedings 50th International Congress of Meat Science and Technology (ICOMST), Helsinki, Finland, p. 77. coma, v. (2008). Bioactive packaging technologies for extended shelf life of meatbased products. Meat Science 78: 90–103. cornforth, d.p., jayasingh, p. (2004). Colour and pigment. In Encyclopedia of Meat Sciences W.K. Jensen, C. Devine & M. Dikeman (Eds.), pp. 249–256. Oxford, UK: Elsevier Ltd. cornforth, d., calkins, c.r., faustman, c. (1991). Methods for identification and prevention of pink color in cooked meats. Reciprocal Meat Conference Proceedings 44: 55–58. datamonitor (2007). Ready Meals: Global Industry Guide. http://www.datamonitor. com. demos, b.p., forrest, j.c., grant, a.l., judge, m.d., chen, l.f. (1994). Low-fat, no added salt in restructured beef steaks with various binders. Journal of Muscle Foods 5: 407–418. dwivedi, s, vasavada, m.n., cornforth, d. (2006). Evaluation of antioxidant effects and sensory attributes of Chinese 5–spice ingredients in cooked ground beef. Journal of Food Science 71: 12–17. eilert, s.j. (2005). New packaging technologies for the 21st century. Meat Science 71: 122–127. esguerra, c.m. (1994). Quality of cold-set restructured beef steaks: effects of various binders, marination and frozen storage. MIRINZ Technical Report 945. MIRINZ Centre, AgResearch, Hamilton, New Zealand. farouk, m.m., swan, j.e. (1997). Acceptability and functional properties of restructured roast from frozen pre-rigor injected beef. Meat Science 46(1): 57–66. farouk, m.m., boles, j.a., mikkelsen, v.l., mcbeth, e.e., demanser, g.c., swan, j.e. (1997). Effect of adjuncts on the color stability of bologna and fresh beef sausages. Journal of Muscle Foods 8: 383–394. farouk, m.m., kemp, r.m., taukiri, k.r. (2002). Adding value to beef and lamb. www. mirinz.com. farouk, m.m., zhang, s.x., cummings, t. (2005a). Effect of muscle-fibre/fibre-bundle alignment on physical and sensory properties of restructured beef steaks. Journal of Muscle Foods 16: 256–273. farouk, m.m., hall, w.k., wieliczko, k.j., swan, j.e. (2005b). Processing time and binder effects on the quality of restructured rolls from hot-boned beef. Journal of Muscle Foods 16: 318–329. farouk, m.m., maqbool, n, knowles, s.o. (2009). Combining foods for enhanced nutrient functionality and not density: a shift in nutrition paradigm. Conference Abstract: New Zealand Institute of Food Science & Technologist (NZIFST) Conference, June 23–25, Christchurch, New Zealand.

© Woodhead Publishing Limited, 2011

474

Processed meats

flores, n.c., boyle, e.a.e., kastner, c.l. (2007). Instrumental and consumer evaluation of pork restructured with Activatm or with Fibrimextm formulated with and without phosphate. LWT – Food Science and Technology 40: 179–185. fraser, e.m., clegg, a.c., martin, a.h. (1993). The use of hot-set binders in restructured lamb roasts. MIRINZ Technical Report 930. fulladosa, e., serra, x., gou, p., arnau, j. (2009). Effects of potassium lactate and high pressure on transglutaminase restructured dry-cured hams with reduced salt content. Meat Science 82: 213–218. gomes, c., castel-perez, m.e., chimbombi, e., barros, f., sun, d., liu, j., sue, h., sherman, p., dunne, p., wright, a.o. (2009). Effect of oxygen-absorbing packaging on the shelf-life of a liquid-based component of military operational rations. Journal of Food Science 74(4): E167–176. gray, j.i., pearson, a.m. (1987). Rancidity and warmed-over flavor. In Advances in Meat Research, Vol 3. Restructured Meat and Poultry Products, edited by Pearson, A.M. and Dutson, T.R., pp. 221–270. New York: Van Nostrand Reinhold Company. guenther, j.j. (1989). Method of realigning fibers in manufacturing meat products. US Patent 4810514. pp 1–17. hedrick, h.b., aberle, e.d., forrest, j.c., judge, m.d., merkel, r.a. (1994). Principles of meat processing. In Principles of Meat Science, 3rd Ed., pp. 133–171. Iowa: Kendall/Hunt Publishing Company. hilton, g.g., carr, m.a., kellermeier, j.d., may, b.j. (2006). Development and consumer acceptance of pre-cooked goat roasts. Sheep & Goat Research Journal 21: 35–39. holownia, k., chinnan, m.s., reynold, a.e. (2003). Pink color defect in poultry white meat as affected by endogenous conditions. Journal of Food Science 68(3): 742–747. hoogenkamp, h.w. (2003). The case for enhancement. Asia Pacific Food Industry 15: 40–41. huang, c.y., mikel, w.b., jones, w.r. (1997). Carrageenan Influences on the characteristics of restructured normal and pale, soft and exudative hams. Journal of Muscle Foods 8: 85–93. hughes, n. (2009). Create Flavours launches fresh tasting herbs range. http://www. foodnavigator.com/Financial-Industry/Create-Flavours-launches-fresh-tastingherbs-range. hunt, m.c., kropf, d.h. (1987). Color and appearance. In Advances in Meat Research, Vol 3. Restructured Meat and Poultry Products, edited by Pearson, A.M. and Dutson, T.R., pp. 125–160. New York: Van Nostrand Reinhold Company. igene, j.o., pearson, a.m. (1979). Role of phospholipid and triglycerides in warmed over flavor development in meat model system. Journal of Food Science 44: 1285–1290. jimenez, a.r. (1999). Study on flavor additives in the meat industry. Alimentaria 36(299): 97–105. jones, w. (2004). Rubbing it in. Prepared Foods, May, 53–54, 56, 58. kellermeier, j.d., hilton, g.g., carr, m.a., may, b.j. (2006). Development and consumer acceptance of pre-cooked lamb leg roasts. Sheep & Goat Research Journal 21: 24–29. kerry, j.p., o’grady, m.n., hogan, s.a. (2006). Past, current and potential utilization of active and intelligent packaging systems for meat and muscle based products: a review. Meat Science 74: 113–130. kim, j.s., godber, j.s., prinaywiwatkul, w. (2000). Restructured beef roasts containing rice branoil and fiber influences cholesterol oxidation and nutritional profile. Journal of Muscle Foods 11: 111–127. king, n.j., whyte, r. (2006). Does it look cooked? A review of factors that influence cooked meat color. Journal of Food Science 71(4): R31–40.

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

475

kotula, a.w., berry, b.w., emswiler-rose, b.s. (1987). Microbiology of restructured meat and poultry products. In Advances in Meat Research, Vol 3. Restructured Meat and Poultry Products, edited by Pearson, A.M. and Dutson, T.R., pp. 161–220. New York: Van Nostrand Reinhold Company. kukoswki, a.c., wulf, d.m., shanks, b.c., page, j.k., maddock, r.j. (2004). Factors associated with surface iridescence in fresh beef. Meat Science 66: 889–893. larsen, h., westad, e., sørheim, o., nilsen, l.h. (2006). Determination of critical oxygen level in packages for cooked sliced ham to prevent color fading during illuminated retail display. Journal of Food Science 71(5): S407–413. lawrence, t.e., hunt, m.c., kropft, d.h. (2002). Surface roughening of precooked, cured beef round muscles reduces iridescence. Journal of Muscle Foods 13: 69–73. lazar, v. (2007). Fried products sizzle. Meat Processing, January, 24–27. lennon, a.m., moon,s.s., ward, p., kenny, t. (2010). Mechanical tenderization of beef muscles for use in re-formed joints made with cold-set binder. Meat Science 84: 651–654. lewis, g.j., purslow, p.p. (1990). Connective tissue differences in the strength of cooked meat across the muscle fibre direction due to test specimen size. Meat Science 28: 183–194. liu, h.f., booren, a.m., gray, j.i., crackel, r.l. (1992). Antioxidant efficacy of oleoresin rosemary and sodium tripolyphosphate in restructured pork steaks. Journal of Food Science 57(4): 803–806. liu, p., watts, b.m. (1970). Catalyst of lipid oxidation in meats. 3 catalyst of oxidative rancidity in meats. Journal of Food Science 35: 596–598. love, j. (1988). Sensory analysis of warmed over flavor in meat. Food Technology 42: 140–143. manu-tawiah, w., ammann, l.l., sebranek, j.g., molins, r.a. (1991). Extending the color stability and shelf life of fresh meat. Food Technology 45(3): 96–98, 100–102. manrique, j., jensen, h.h. (1997). Spanish household demand for convenience meat products. Agribusiness 13(6): 579–586. mcguire, a.e.r. (2009). Manufacturing restructured meat products. Meeting Place In print Online: http://www.meatingplace.com/MembersOnly/technology/details. aspx?item=10035. Accessed May 2, 2009. mendenhall, v.t. (1989). Effect of pH and total pigment concentration on the internal color of cooked ground beef patties. Journal of Food Science 54: 1–2. mielnik, m.b., sem, s., egelandsdal, b., skrede, g. (2008). By-products from herbs essential oil production as ingredient in marinade for turkey thighs. LWT – Food Science and Technology 41: 93–100. mikkelsen, v.l., esguerra, c.m. (1996). Restructured Beef Cubes Manufactured from Alginate-Bound Meat. MIRINZ Technical Report 965. miller, m.f., davis, g.w., seindeman, c.b., ramsey, c.b., rolan, t.l. (1988). Effects of papain, ficin and spleen enzymes on textural, visual, cooking and sensory properties of beef bullock restructured steaks. Journal of Food Quality 11: 321–330. moiseev, i.v., cornforth, d.p. (1999). Treatments for prevention of persistent pinking in dark-cutting beef patties. Journal of Food Science 64: 738–743. møller, j.k.s., bertelsen, g., skibsted, l.h. (2002). Photooxidation of nitrosylmyoglobin at low oxygen pressure. Quantum yields and reaction stoichiometrics. Meat Science 60: 421–425. molins, r.a., kraft, a.a., walker, h.w., rust, e., olson, d.g., merkenich, k. (1987). Effect of inorganic polyphosphates on ground beef characteristics: some chemical, physical and sensory effects on frozen beef patties. Journal of Food Science 52: 50–52. nunez-gonzalez, f.a., garcia-macias, j.a., rios-rincon, f.g., hernandez-bautisita, j., ortega-gutierrez, j.a. (2005). Incidence and characteristics of iridescent bovine

© Woodhead Publishing Limited, 2011

476

Processed meats

meat. Proceedings Western Section, American Society of Animal Science 56: 249–253. obuz, e., kropf, d.h. (2002). Will blade tenderization decrease iridescence in cooked beef semimembranosus muscle? Journal of Muscle Foods 13: 75–79. o’donnell, c.d. (2009). Formulation trends in processed meats and alternatives. Prepared Foods, January, 115–120. o’grady, m.n., kerry, j.p. (2008). Smart packaging technologies and their application in conventional meat packaging systems. In Meat Biotechnology, edited by Toldrá, F. pp. 425–451. New York: Springer. okayama, t., imai, t., yamanoue, m. (1987). Effect of ascorbic acid and alpha-tocopherol on storage stability of beef steaks. Meat Science 21: 267–273. otremba, m.m., dikeman, m.e., milliken, g.a., stroda, s.l., unruh, j.a., chambers iv, e. (1999). Interrelationships among evaluations of beef longissimus and semitendinosus muscle tenderness by Warner-Bratzler shearforce, a descriptive-texture profile sensory panel, and a descriptive attribute sensory panel. Journal of Animal Science 77: 865–873. parlin, s. (2004). Streamlining microwave packaging. National Provisioner, April, 86–89. pearson, a.m., dutson, t.r. (Eds) (1987). Advances in Meat Research Vol 3. Restructured Meat and Poultry Products’ New York: Van Nostrand Reinhold Company. pearson, a.m., gillet, t.a. (1999). Processed Meats, 3rd ed. Gaithersburg, MD: Aspen Publishers. pearson, a.m., gray, j.i. (1983). Mechanisms responsible for warmed over flavor (WOF) in cooked meats. ACS Symposium Series 215, Washington, DC. pellegrini, m (2007). Express lane: for now, at least, consumers are willing to pay a higher price for premium product. The National Provisioner, August, 44. pellegrini, m. (2008). Batter and breadings function vs flavor. National Provisioner, March, 48–56. poste, l.m., butler, g., mackie, d., agar, v.e., thompson, b.k. (1993). Correlations of sensory and instrumental meat tenderness values as affected by sampling techniques. Food Quality and Preference 4: 207–214. pszczola, d.e. (2002). Beefing up innovations for meat and poultry ingredients. Food Technology 56(3): 54–79. pszczola, d.e. (2004). Flavor enhancement: Taking the mask off. Food Technology 58(8): 56–69. pszczola, d.e. (2010). Takling meaty issues in a lean economy. Food Technology 64(4): 49–58. purslow, p.p., donnelly, s.m., savage, a.w.j. (1987). Variations in the tensile adhesive strength of meat-myosin junctions due to test configurations. Meat Science 19: 227–242. reverte, d., xiong, x.l., moody, w.g. (2003). Properties of restructured beef steaks from forage- and grain-fed cattle as affected by antioxidant and flavoring agents. Meat Science 65: 539–546. robins, k., jensen, j., ryan, k.j., homco-ryan, c., mckeith, f.k., brewer, m.s. (2003). Consumer attitudes towards beef and acceptability of enhanced beef. Meat Science 65: 721–729. robinson, r. (1998). Survey says smoke it. National Provisioner, December, 44–48. rojas, m.c., brewer, m.s. (2007). Effect of natural antioxidants on oxidative stability of cooked, refrigerated beef and pork. Journal of Food Science 72(4): S282–288. rts (2006). Western Europe Ready Meals 2010. www.rts-resource.com. saba, a., messina, f., turrini, a., lumbers, m., raats, m.m., the food in later life project team (2008). Older people and convenience in meal preparation: a European study on understanding their perception towards vegetable soup preparation. International Journal of Consumer Studies 32: 147–156.

© Woodhead Publishing Limited, 2011

Improving the quality of restructured and convenience meat products

477

saltzer, m. (2009). Tyson introduces new fully cooked refrigerated meals. MeatingPlace In Print Online: http://www.meatingplace.com/MembersOnly/webNews/ details.aspx?item=12229. Accessed 6 May 2009. sammel, l.m., claus, j.r., greaser, m.l., lucey, j.a. (2007). Identifying constituents of whey protein concentrates that reduce the pink color defect in cooked ground turkey. Meat Science 77: 529–539. savage, a.w.j., donnelly, s.m., jolley, p.d., purslo, p.p., nute, g.r. (1990). The influence of varying degrees of adhesion as determined by mechanical tests on the sensory and consumer acceptance of a meat product. Meat Science 28: 141–158. savage, b. (1999). Pre-cooked meats. Meat Marketing & Technology, February, 46–51. shahidi, f., rubin, c.j., diosady, l.l., kassam, n., li sui fong, j.c. (1986). Effect of sequestering agentson lipid oxidation in cooked meats. Food Chemistry 21: 145–152. sheard, p. (2002). Processing and quality control of restructured meat. In Meat Processing: Improving Quality, edited by Kerry, J., Kerry, J. and Ledward, D., pp. 332–358. Cambridge, England: Woodhead Publishing Limited. sindelar, j.j., cordray, j.c., sebranek, j.g., love, j.a., ahn, d.u. (2007). Effects of varying levels of vegetable juice powder and incubation time on color, residual nitrate and nitrite, pigment, pH, and trained sensory attributes of ready-to-eat uncured ham. Journal of Food Science 72(6): S388–395. sloan, a.e. (2000). Beefing it up. Food Technology 54(3): 22. sloan, a.e. (2008). What, when, and where America eats. Food Technology, January, 20–29. stika, j.f., suman, s.p., xiong, y.l. (2008). Frozen storage stability of vacuum-packaged precooked restructured steaks manufactured from mature cow beef. LWT – Food Science and Technology, 41(9): 1535–1540. swan, j.e., farouk, m.m., mcbeth, e.e., de manser, g.c. (1997). Processed meat products in a changing world. Proceedings, 43rd ICOMST, Auckland, New Zealand, 164–168. swatland, h.j. (1984). Optical characteristics of natural iridescence in meat. Journal of Food Science 49(3): 685–686. swatland, h.j. (1988). Interference colors of beef fasciculi in circularly polarized light. Journal of Animal Science 66: 379–384. swienteck, b. (2008). Hot times for heat & eat foods. Food Technology, June, 61–69. trout, g.r., schmidt, g.r. (1987). Non protein additives. In Advances in Meat Research, Vol 3. Restructured Meat and Poultry Products, edited by Pearson, A.M. and Dutson, T.R., pp. 307–330. New York: Van Nostrand Reinhold Company. van laack, r.l.j.m., solomon, m.b., warner, r., kauffman, r.g. (1996). A comparison of procedures for measurement of pigment concentration in pork. Journal of Food Science 61: 410–163. vote, d.j., platter, w.j., tatum, j.d., schmidt, g.r., belk, k.e., smith, g.c., speer, n.c. (2000). Injection of beef strip loins with solutions containing sodium tripolyphosphate, sodium lactate, and sodium chloride to enhance palatability. Journal of Animal Science 78: 952–957. wray, t. (2008). Redefining the freezer. National Provisioner, January, 80, 82, 84. younathan, m.t., marjan, z.m., arshad, f.b. (1980). Oxidative rancidity in stored ground turkey and beef. Journal of Food Science 45: 274–278. young, o.a., cummings, t.l. (2008). Effect of xylose on sheepmeat flavours in casserole-style cooking. Journal of Food Science 73(6): S308–313. zarringhalami, s., sahari, m.a., hamidi-esfehani, z. (2009). Partial replacement of nitrite by annatto as a colour additive in sausage. Meat Science 81: 281–284.

© Woodhead Publishing Limited, 2011

19 Heat and processing generated contaminants in processed meats P. Šimko, Food Research Institute, Slovak Republic and Brno University of Technology, Czech Republic

Abstract: This chapter discusses selected aspects of the formation, occurrence, prevention and elimination procedures of contaminants in processed meat products. During the technological and culinary treatment of meat, conditions are favourable for the formation of compounds harmful to human health. Such compounds include polycyclic aromatic hydrocarbons, which can contaminate meat during smoking, grilling and roasting; N-nitroso amines, which may form during salting and thermal treatment; and biogenic amines, which form during ripening. Microbial spoilage of meat products is also an issue. Finally, heterocyclic amines can form in meat and in meat products during frying, barbecuing and grilling. This chapter also includes some data on legislation limits, where these exist, as well as an outline of the analytical procedures, finding and occurrence in various meat matrices. Key words: meat, polycyclic aromatic hydrocarbons, biogenic amines, N-nitroso amines, heterocyclic amines, smoking, brining, ripening, frying, barbecue.

19.1 Polycyclic aromatic hydrocarbons (PAHs) 19.1.1 Introduction Heat treatment of meat products can be said to have begun when our ancestors learnt to use fire. Apart from direct meal preparation techniques such as grilling, roasting and other forms of cooking, it was probably a need to protect his meat from other hunters which led man to hang a kill over the fire. Since then, smoking has been widely employed, not only as a method of producing meat products with a special organoleptic profile, but also as a method of preservation by inactivating tissue enzymes and microorganisms. Over time, techniques for smoking meat have been gradually improved and various procedures developed in different regions for treating meat and fish. Nowadays, the technology is used mainly to enrich foods with a specific

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

479

taste, odour and appearance, to meet demand from consumers all over the world (Šimko, 2005). However, the importance of the preservative effects of smoking meat is gradually declining due to the latest trends in alternative preservation procedures. Today it is reported that smoking is used (in many forms) to treat approximately 40–60% of the total amount of value added meat products processed (Sikorski, 2004).

19.1.2 Principles of smoking In general, smoke is a polydisperse mixture of liquid and solid components with diameters of 0.08–0.15 μm in gaseous phase of air, carbon oxide, carbon dioxide, water vapour, methane and other gases. Smoke has a variable composition which depends on such conditions as procedure and temperature of smoke generation, origin, species and composition of wood, as well as water content in wood, etc. (Sikorski, 2004). Over 1100 various chemical compounds have been identified within smoke samples and have been widely published in the literature (Wilms, 2000). The smoking treatment itself is based on successive deposition of compounds such as phenol derivates, carbonyls, organic acids and their esters, lactones, pyrazines, pyrols and furan derivates (Maga, 1987) on a food surface, and their subsequent migration into the food bulk (Strmisková et al., 1987). Smoke is generated during thermal combustion of wood consisting of roughly 50% cellulose, 25% hemicellulose and 25% lignin, with limited access to oxygen. The thermal combustion of hemicelluloses, cellulose and lignin proceeds at 180–300, 260–350 and 300–500 °C, respectively. However, the decomposition of the wood components also occurs at temperatures reaching up to 900 °C and even at temperatures of 1200 °C when there is a large amount of oxygen. The smoke produced at 650–700 °C is richest in components capable of imparting desirable organoleptic properties in treated products. The temperature at which smoke is generated can be lowered by increasing the wood moisture content (Tóth & Potthast, 1984). Procedures of smoking and flavouring by employing liquid smoke flavours are discussed in Chapter 21.

19.1.3 Characterisation of polycyclic aromatic hydrocarbons (PAHs) Apart from the compounds previously mentioned, there are also potential conditions suitable for formation of other compounds during smoke production. One of the most important groups that can be generated which are actually harmful to human health is that of the polycyclic aromatic hydrocarbons (PAHs). These compounds are formed during the thermal decomposition of wood, especially at times of limited access of oxygen in the temperature range of 500–900 °C (Bartle, 1991). PAHs have a strong lipophilic character and consist of two or more condensed aromatic rings linked together, either cata-annellated (linearly, or angularly) or peri-condensed. Cata-condensed PAHs are alternant systems containing only six-membered

© Woodhead Publishing Limited, 2011

480

Processed meats

rings and closed shell systems, with all bonding orbitals occupied by two electrons. The entire group of cata-condensed PAHs can be further divided into branched and non-branched systems. Branched systems are thermodynamically more stable and chemically less reactive than non-branched systems of the same size. Conversely, peri-condensed PAHs are either closed shell systems or neutral free orbitals, in which at least one electron is in a non-bonding orbital. Free radicals of this type are stable only if the systems have an odd number of carbon atoms. In addition, peri-condensed PAHs can be further divided into alternant and non-alternant, depending on the presence of five-or six-membered rings in the molecule (Guillén, 1994). These variables, including the existence of alkylated derivatives, make for a large number of various isomers. The temperature of smoke generation plays a decisive role because the amounts of PAHs contained in smoke increases linearly with the temperature of smoke generation in the interval of 400–1000 °C (Tóth and Blaas, 1972). Apart from the formation itself, the temperature also affects structure and number of PAHs. Up to 100 PAH compounds can be present in smoked products (Grimmer and Böhnke, 1975), all having different effects on living organisms. However, PAHs are also formed during direct thermal meat treatments such as roasting, grilling and frying. Fat is the main source of hydrocarbons and formation of PAHs at charcoal broiling is dependent directly on the fat content of the meat. It was proved that melted fat from heated meat drips onto the hot coals is thermally decomposed, giving rise to the formation of PAHs, which are then deposited on the meat surface as the smoke rises (Larsson et al., 1983).

19.1.4 Behaviour of PAHs in organisms The potential of PAHs chemicals to cause cancer arose from the observations of Percival Pott of St Bartholomew’s Hospital in London in 1775 when he noted a high incidence of cancer of the scrotum among chimneysweeps who often had to climb inside chimneys to sweep the soot down. Although he had deduced correctly that the soot was responsible for the cancer, at this time it was not possible to determine the compounds responsible for such serious tissue damage. In 1920, Japanese workers discovered that painting extracts of soot onto the skin of mice caused tumours of the skin. In 1929, the first pure chemical carcinogen dibenzo[a,h]anthracene was isolated from soot extract at the Chester Beatty Research Institute. In 1953, on the basis of wide epidemiological and statistical analysis it was proved that cigarette smoking was a prime cause of lung cancer. Careful analysis of the smoke and tar obtained from cigarettes showed, that it contained many carcinogenic PAHs, of which benzo[a]pyrene (BaP) was assessed as the most dangerous compound. According to current knowledge, some PAHs are able to interact in organisms with enzymes (such as aryl hydrocarbon hydroxylases) to form PAH dihydrodiol derivates. These reactive

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

481

products (so-called ‘bay region’ dihydrodiol epoxides) are believed as ultimate carcinogens that are able to form covalently bounded adducts with proteins and nucleic acids. In general, DNA adducts are thought to initiate cell mutation which is resulting in a malignancy (Bartle, 1991). A direct mutagenic potential of 14 PAHs and PAHs containing fractions isolated from smoked and charcoal broiled samples, was studied towards strains TA 98 and TA 100 using the Ames test. The most potential mutagenicity was observed on PAH fractions isolated from smoked fish, treated before smoking with nitrites in an acid solution (Kangsadalampai et al., 1997). To simplify an interpretation of real risk of PAHs to human health, there have been attempts to express objectively the real risk using toxic equivalency factors (Nisbet and La Goy, 1992). However, this approach does not reflect wider aspects of the potential toxicity of oxidised PAHs products due to the effect of ultraviolet (UV) light, as well as other environmental factors (Law et al., 2002). Moreover, the PAH content of smoked foods can be affected not only by environmental factors, but also by diffusion processes into plastic packaging materials (Šimko, 2005).

19.1.5

Legislative aspects and international normalisation of PAHs in smoked meat Because of the harmful effects of PAHs on living organisms, varying limitations have been placed on the quantities of these compounds in smoked meat products in the past by some European countries. To simplify problems associated with the variability of PAH composition, the presence of BaP had been accepted as the standard indicator of total PAH presence in smoked foods, despite the fact that BaP constitutes between only 1 and 20% of the total carcinogenic PAHs (Andelman and Suess, 1970). The current situation in the EU has seen a unified approach through the adoption of the EC Regulation 1881/2006, limiting BaP content at level of 5 μg kg−1 in smoked meats, smoked meat products, muscle meat of smoked fish and smoked fishery products (Commission Regulation 1881/2006/EC). Apart from this, the EC has also adopted either the Directive 2005/10/EC, which lays down the official sampling and analytical methods for control of BaP levels in foodstuffs (Commission Directive 2005/10/EC), or the Commission Recommendation 2005/108/EC on further investigation into PAH levels in certain foods. PAHs investigated included benzo[a]anthracene (BaA), benzo[b]fluoranthene (BbF), benzo[j]fluoranthene (BjF), benzo[k]fluoranthene (BkF), benzo[g,h,i]perylene (BghiP), chrysene (Chr), BaP, cyclopenta[c,d]pyrene (CcpP), dibenzo[a,h]anthracene (DahA), dibenzo[a,e] pyrene (DaeP), dibenzo[a,h]pyrene (DahP), dibenzo[a,i]pyrene (DaiP), dibenzo[a,l]pyrene (DalP), indeno[1,2,3-cd]pyrene (IcdP) and 5-methylchrysene (Commission Recommendation 2005/108/EC). Moreover, the Joint Expert Committee for Food Contaminants and Additives of FAO and WHO (JECFA) has defined another compound, benzo[c]fluorene (BcF),

© Woodhead Publishing Limited, 2011

482

Processed meats

which should be monitored with regard to its carcinogenous effects to living organisms. Concerning liquid smoke flavours (LSF), which are sometimes used as an alternative to the traditional smoking process, the EC has adopted the Commission Regulation 2065/2003 relating to the production of smoke flavourings used as food flavouring (Commission Regulation 2065/2003/ EC). This regulation has limited the maximum acceptable concentrations of BaP at 10 μg kg−1 and BaA at 20 μg kg−1 in these products. Finally, Directive 88/388/EEC has placed a limit of 0.03 μg kg−1 on the maximum residual levels of BaP in foodstuffs flavoured by LSF (Commission Directive 88/388/ EC). For international trade purposes, the JEFCA has adopted a specification which tolerates liquid smoke flavours at the concentration levels of 10 μg kg−1 for BaP, and 20 μg kg−1for BaA, respectively (JEFCA, 1987).

19.1.6 Analysis of PAHs PAHs are usually detected within foods at the μg kg−1 level. Therefore, in order to achieve this level of detection, analysis is completed as follows: extraction/hydrolysis, liquid/liquid partition, clean-up procedures, concentration, chromatographic separation and, of course, determination. Although each step is very important, the chromatographic separation is perhaps the most important to ensure correct evaluation of real risk assessment, because while BaP is a very strong carcinogenic agent, carcinogenic activity of its isomer BeP is quite low. Methodology of PAH analysis was strongly affected the development of chromatographic methods. At the beginning, a separation of BaP isomers by paper chromatography (PC) and column chromatography (CC) was practically impossible. With regard to complex mixtures of PAHs, the presence of a variety of interfering substances and the need to assess correctly the real concentrations of the most dangerous compounds at very low concentration levels, it was necessary to overcome problems regarding the resolution of so-called ‘benzpyrene fraction’ which consists of BaP and its isomers BeP, BkF, BbF and Per (Howard and Fazio, 1969). Currently, gas chromatography – mass spectrometry (GCMS) and high pressure liquid chromatography – mass spectrometry (HPLC-MS), or UV and fluorimetric detection are the most common techniques used for determination of PAHs in meat products and separate satisfactorily such critical isomers as BbF, BjF and BkF (Šimko, 2002; Tamakawa, 2004; Djinovic et al., 2008a, 2008b; Purcaro et al., 2009).

19.1.7 Occurrence of PAHs Once information regarding the carcinogenic effect of key compounds was established, research workers commenced their work in order to establish the real situation of PAH content in smoked meat products. The data generated from these studies has shown that employing the correct smoking

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

483

process (e.g. indirect smoking) can significantly reduce contaminates in final products with minimal PAHs content – usually bellow 1 μg kg−1 (Roda et al., 1999). Far more dangerous smoking processes are realised when employing the uncontrolled conditions typical of home ‘wild’ smoking in preparation of heavy smoked ‘farm’ products. Similar crude smoking conditions can be identified in developing countries where there is a lack of technological knowledge and poor hygiene control. These products pose a serious and real risk of cancer of the digestive tract to consumers, especially after consumption of such PAH-containing products over an extended period of time (Šimko, 2002; Dobríková & Sveˇtlíková, 2007). PAHs content in smoked meat products is believed to be a relatively constant value, unaffected by environmental factors. However, PAHs localised on the surface of meat products might be oxidised by extrinsic factors (e.g. light, oxygen) forming oxidised derivates, which bring about a lowering of the overall PAHs content (Šimko, 1991). An effective way to eliminate PAHs in meat products is their sorption on the surface of plastic packaging. Šimko and Bruncková (1993) decreased PAH content in liquid smoke flavours by two orders during two weeks. As found later, the rate-limiting step of PAH elimination was diffusion of these compounds in liquid media (Šimko et al., 1994). Chen and Chen (2005) reduced BaP content in roasted duck skin packed into low density polyethylene (LDPE) by 75% during 24 hours. Efficiency of PAH elimination in general depends on the polarity of the food matrix, the polarity of the plastic package, the distribution coefficient between both phases, other compounds capable of competing for adsorption on package surface, the ability of PAHs to interact with other compounds in the food matrix and package, and the measure of physicochemical processes such as diffusion and/or adsorption (Šimko, 2005). Relating to grilling and barbecue application, meat should not be treated over a burning log fire, but only over embers formed after initial combustion of the fuel. An adequate distance should be maintained between the smoke generation source (fuel) and the product. Summarised data about findings and occurrence of BaP in smoked, barbecued and grilled meat products are shown in Table 19.1.

19.2 Biogenic amines (BAs) 19.2.1 Characterisation Biogenic amines (BAs) are low molecular alkaline compounds with aliphatic (putrescine, cadaverine, spermine, spermidine), aromatic (tyramine, phenylethylamine) or heterocyclic (histamine, tryptamine) structure, respectively (Silla Santos, 1996). They are formed by microbial decarboxylation from their precursors, which are corresponding free amino acids. Some authors also assign to BAs so-called polyamines, which are formed from amino acids, biogenic amines and polyamines, as shown in Table 19.2.

© Woodhead Publishing Limited, 2011

484

Processed meats

Table 19.1

BaP content in smoked, barbecued and grilled meat products No. of analysed/ positive samples

Sample

Content of BaP (μg kg−1) Min.

Max. 4.5

Barbecued pork and beef

2/2

2.5

Frankfurters grilled by various ways Charbroiled hamburgers Fried hamburgers Ham, bacon, fish, sausage

5/5

0.1

2/2 2/0 19/19

1.5 – 0.3

4.0 – 18

Frankfurters, meat, sausages Ham, pork, meat products Sausages, spread, salami, fish Fermented products, frankfurters Sausages, special products Dark smoked meat products Heavy smoked sausage Cooked out fat of sausage Sausage, pork Ham, bacon Sausage, fish, pork tasso Sausages, poultry, bacon Ribbons, ham, sausages, bacon Mutton meat Salami, bacon

8/8 74/69 17/17 17/7

0.1 0.2 0.1 0.05

12.0 56.5 9.5 0.15

Heavy smoked ham, products Smoked cured ham, smoked raw sausage Barbecued meat sausages

196/196

Smoked beef ham, smoked pork ham Smoked beef ham, smoked pork ham, bacon without skin, bacon with skin, cajna sausage and sremska sausage Smoked pork meat Smoked meat products (sausage, pork, beef, bacon)

386 5/5 1/1

212

Ref.

Howard and Fazio (1969) Larsson et al. (1983) Lawrence and Weber (1984) Stijve and Hischenhuber (1997) Roda et al. (1999) Potthast (1978) Šimko et al. (1991) Fretheim (1976)

100 39.9

2/2 3/3 5/0 5/3 6/5

0.6 17.1 4.8 7.7 0.3 0.2 – 0.1 0.2

5.2 0.4 – 0.4 1.3

Cejpek et al. (1995) Joe et al. (1984) Wang et al. (1999) Gomaa et al. (1993) Yabiku et al. (1993)

5/5 4/4

0.1 0.2

5.6 0.5

Dennis et al. (1984) Lintas & de Matthaeis (1979) Räuter (1997)

0.03

>10.0

Binnemann (1979) Šimko et al. (1989) Šimko et al. (1993)

18/18

0.1

0.4

Jira (2004)

7/2

0.3

2.8

4/4

0.1

0.3

6/6

0.2

1.0

Mottier et al. (2000) Djinovic et al. (2008a) Djinovic et al. (2008b)

11/11

6.0

35.1

8/4

0.1

0.8

© Woodhead Publishing Limited, 2011

Stumpe-Viksna et al. (2008) Purcaro et al. (2009)

Heat and processing generated contaminants in processed meats

485

Table 19.2 Precursors and corresponding biogenic amines and polyamines Precursor

Biogenic amine

Histidine Tyrosine Tryptophane Phenylalanine Lysine Ornithine Putrescine Spermidine

Histamine Tyramine Tryptamine Phenylethylamine Cadaverine Putrescine Spermidine Spermine

BAs can be formed during storage or processing of products by thermal or bacterial enzymatic decarboxylation of free amino acids by Enterobacteriaceae and Enterococcus species naturally present on fish, meat and products thereof.

19.2.2 Toxicological considerations The BA content of various foods has been widely studied because of its potential toxicity. BAs such as tyramine and phenylethylamine have been proposed as the initiators of hypertensive crisis in certain patients and of dietary-induced migraine. Another amine, histamine, has been implicated as the causal agent in several outbreaks of food poisoning. Histamine intake within 8–40, 40–100 and higher than 100 mg may cause slight, intermediate and intensive poisoning, respectively (Parente et al., 2001). Nout (1994) pointed out that the maximum allowable level of histamine and tyramine in foods should be in the range of 50–100 mg kg−1 and 100–800 mg kg−1, respectively; over 1080 mg kg−1 tyramine the compound becomes toxic to humans. Histamine is the only biogenic amine subjected to legal regulations in some fish species, with an upper limit of 100 mg kg−1 in European Union (Commission Regulation 2073/2005). However, there is no legislative limit reported for BA content in meat and fermented sausages. Some authors have suggested a level of 100 mg kg−1 of histamine as a limit to establish potential risk for healthy individuals (Brink et al., 1990). Hernández-Jover et al. (1996) proposed a biogenic amine index (BAI) which is calculated as the sum of cadaverine, putrescine, tyramine and histamine present in a meat. The following limits for BAI have been suggested: <5 mg kg−1 for fresh meat, between 5 and 20 mg kg−1 for acceptable meat (with initial signs of spoilage), between 20 and 50 mg kg−1 for low meat quality and, finally, >50 mg kg−1 for spoiled meat. Putrescine, spermine, spermidine and cadaverine have no adverse health effects, but they may react with nitrite to form carcinogenic N-nitroso amines and also can be proposed as general indicators of meat spoilage

© Woodhead Publishing Limited, 2011

486

Processed meats

(Eerola et al., 1997). Tryptamine has been shown to have toxic effects on human beings manifested as blood pressure increase, and hypertension (Shalaby, 1994). Food poisoning may occur especially in conjunction with potentiating factors such as monoamine oxidase-inhibiting (MAOI) drugs, alcohol, gastrointestinal diseases and other food amines. Histaminic intoxication, hypertensive crisis due to interaction between food and MAOI antidepressants, and food-induced migraines are the most common reactions associated with the consumption of food containing large amounts of biogenic amines (Önal, 2007). The diamines (putrescine and cadaverine) and the polyamines (spermine and spermidine) have been shown to favour the intestinal absorption and decrease the catabolism of the above amines, and such way increase their toxicity (Bardócz, 1993). The formation of N-nitroso amines, which are potential carcinogens, constitutes an additional toxicological risk associated to BAs, especially in meat products that contain nitrite and nitrate salts as curing agents in processed meats (Scanlan, 1983; Honikel, 2008). Determination of the exact toxicity threshold of BAs within individuals is extremely difficult, since the toxic dose is strongly dependent on the efficiency of the detoxification mechanisms of each individual (Halász et al., 1994). Normally, during the food intake process in the human gut, low amounts of biogenic amines are metabolised to physiologically less active degradation products. This detoxification system includes specific enzymes such as diamine oxidase (DAO). However, upon intake of high loads of biogenic amines in foods, the detoxification system is unable to eliminate these biogenic amines sufficiently. Moreover, in the case of insufficient DAO activity, caused for example by generic predisposition, gastrointestinal disease or inhibition of DAO activity due to secondary effects of medicines or alcohol, even low amounts of biogenic amines cannot be metabolised efficiently (Bodmer et al., 1999). Some biogenic amines, e.g. histamine and tyramine, are considered as antinutritive compounds. For sensitive individuals they represent a health risk, especially when their effect is potentiated by other substances. Poisoning by histamine with its allergy-like symptoms is usually related to the consumption of scombroid fish such as tuna or mackerel and is considered to be one of the commonest forms of food intoxication reported (Veciana Nogue et al., 1997). Interest in biogenic amine content of food, in particular fermented sausages, lies in the area of safety and quality issues. From a toxicological point of view, the vasoactive and psychoactive effects of tyramine and histamine are related to the occurrence of histaminic intoxication, food-induced migraines and hypertensive crises in sensitive individuals. The risk of health implications may be increased when the efficiency of enzymatic systems is blocked by monoamine oxidase inhibitors, gastrointestinal diseases, genetic deficiencies, or potentiating factors such as alcohol or other biogenic amines (Brink et al., 1990). Furthermore, some biogenic amines (mainly cadaverine and histamine) have been proposed as chemical indicators of the hygienic conditions of raw material and/or

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

487

manufacturing practices since their accumulation is associated with the activity of contaminant bacteria (Bover-Cid et al., 2000, 2001, 2003; Hernández-Jover et al., 1997).

19.2.3 Technological effects on BA content Among the numerous studies on biogenic amines in fermented sausages, a number have focused on traditional manufacturing operations (Parente et al., 2001; Latorre-Moratalla et al., 2008). In this kind of traditional sausage, the occurrence of BAs was considerable higher than industrial produced products. The content and profiles depend on several extrinsic and intrinsic factors realised during the manufacturing process, such as the ripening conditions employed, formulation type, physico-chemical and proteolytic parameters during ripening, as well as microflora development and its decarboxylase activity (Latorre-Moratalla et al., 2008). Considerable development of microflora activity was also observed in unpacked and vacuumpackaged beef products stored at 4 °C. In unpacked samples, the total amine content increased over time, reaching 5 mg g−1 (after 8 days). On the 12th day it reached 16.5 mg g−1, showing abnormal sensorial characteristics with these samples being disqualified. Although vacuum-packed samples appeared sensory acceptable at the end of storage (35th day), total amine content approached 5 mg g−1 from the 12th day, without exceeding 100 mg g−1. This indicates that decreases in hygiene quality in the production have a negative impact on the level of chemical residues in final products (Kaniou et al., 2001). Smeˇlá et al., (2003) observed considerable increasing of BA in fermented sausage during ripening and after 16 weeks of storage, while the content of the polyamines permidine and spermine was reduced by 50%, or 60%, respectively.

19.2.4 Determination of BAs Various methods have been developed for the analysis of BAs in foods such as thin-layer chromatography (TLC), gas chromatography, capillary electrophoretic method and HPLC. The pre-cleaning procedure comprises the extraction of BAs from the food matrix with suitable extracting solvents. For meat and meat products, trichloroacetic acid, perchloric acid, hydrochloric acid and methanol seem to be the most efficient extraction solvents (Tamim et al., 2002). TLC is simple and does not require special equipment, but most of the published methods suffer from excessive time needed for analysis and/or inaccuracy of the obtained results. Gas chromatography is not frequently used for the determination of BAs. A biosensor procedure has advantages, such as low cost, rapid analysis time, simplicity of use and it can be employed outside the laboratory in the field. HPLC with pre- or post-column derivatisation is by far the most frequently reported technique for BA separation and quantification. Owing to the lack of chromophores

© Woodhead Publishing Limited, 2011

488

Processed meats

in native molecules, the majority of derivatisation procedures (pre- or postcolumn) have been usually applied as dansyl and dabsyl chloride, benzoyl chloride, fluoresceine, 9-fluorenylmethyl chloroformate, o-phthalaldehyde, naphthalene-2,3-dicarboxaldehyde. o-Phthalaldehyde can easily react with primary amines within about 30 seconds in the presence of a reducing reagent, such as N-acetylcyteine or 2-mercaptoethanol. However, the derivatives are not very stable. Dabsyl and dansylchloride react with both primary and secondary amino groups and provide stable derivatives. Dansyl chloride has been the most widely used reagent. For the detection of these end compounds, fluorescence, UV and electrochemical detectors are frequently used (Önal, 2007).

19.2.5 Occurrence of BAs in meat and meat products As previously mentioned, BAs can form in meat products due to unsuitable hygienic conditions employed during slaughtering, deboning and/or storage. Poor hygienic conditions can also affect BAs content in final meat products. Apart from this, elevated BA content can be brought about by microflora utilised for production of fermented meat products such as sausage and salami. Finally, the extension of the shelf-life of meat products via vacuum/ or modified atmosphere packaging conditions can also affect ultimate BA content of these foods. Measured data of BA content in various meat products are shown in Table 19.3.

19.3

N-nitroso amines (NAs)

19.3.1 Introduction The use of nitrites and nitrates in the processing of meats began roughly 100 years ago and N-nitroso amines (NAs) were originally synthesised by reaction of secondary amines with nitrous acid. The usage of these reagents in various industries as solvents ceased when their potential toxicity was discovered in 1937 (Freud, 1937). Freud (1937) observed that some animals exposed to N-nitroso dimethylamine (NDMA) vapours deceased due to progressive liver necrosis development. The suspicion that NAs could also be contained in foods was based on observations of liver tumour formation factors within animals that had been fed herrings preserved with nitrites (Ender et al., 1967). Subsequently various food – including meat products – were studied and reported for NA content (Ender & Ceh, 1971; Telling et al., 1971; Sen, 1972; Sen et al., 1979).

19.3.2 Physical and chemical properties of NAs NAs are part of a large chemical group defined as N-nitroso compounds, which also consists of N-nitrosamides (NADs). Although both groups are

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats Table 19.3

489

Content of biogenic amines in meat and meat products

Product/no. of samples Pork meat/13

Beef/6

Spanish cooked ham/20

Spanish mortadella/20

Spanish ripened meat products/60

French ripened sausages/10

Italian ripened sausages/10

Greek ripened sausages/10

Compound Spermine Spermidine Tyramine Histamine Putrescine Cadaverine Spermine Spermidine Tyramine Histamine Putrescine Cadaverine Spermine Spermidine Tyramine Histamine Putrescine Cadaverine Spermine Spermidine Tyramine Histamine Putrescine Cadaverine Tyramine Histamine Putrescine Cadaverine Tryptamine Phenylethylamine Tyramine Putrescine Cadaverine Histamine Phenylethylamine Tryptamine Tyramine Putrescine Cadaverine Histamine Phenylethylamine Tryptamine Tyramine Putrescine Cadaverine Histamine Phenylethylamine Tryptamine

Minimal content (mg kg−1)

Maximum content (mg kg−1)

27.3 0.8 0 0 0 0 28.7 1.9 0 0 0 0 6.4 1.4 0 0 0 0 7.6 1.0 0 0 0 0 29.2 0 1.8 0 0 0 5.5 0.4 0 0 0 0 70.3 3,7 0.4 0 0 0 14.3 0 0 0 0 0

40.6 4.5 0 0 0 0 44.6 4.2 0 0 0 0 62.1 3.5 78.1 0.9 12.4 9.5 32.2 8.9 67 4.8 5.7 28.8 742.6 357.7 500.7 658.1 87.8 51.5 186.9 362 389.8 41.7 54 19.1 302.9 324.2 352.2 8.8 43 17 272.2 126.4 242.6 105.8 20.7 48.2

© Woodhead Publishing Limited, 2011

Source Hernández-Jover et al. (1997)

LatorreMoratalla et al. (2008)

490

Processed meats

Table 19.3 Continued Product/no. of samples Portugal ripened sausages/11

Slovakian ripened sausages/3

Salami/3

Austrian salami/52 Austrian raw sausage/32 Hungarian salami/8 Czech fermented salami/1

Compound Tyramine Putrescine Cadaverine Histamine Phenylethylamine Tryptamine Tyramine Putrescine Cadaverine Histamine Phenylethylamine Tryptamine Putrescine Cadaverine Histamine

Minimal content (mg kg−1)

Maximum content (mg kg−1)

9.7 4.3 2.74 0 0 0 0 0 0 0 0 0 163.0 10.1 5.2

266.8 352.2 484.5 94.7 45.6 36.1 117.9 61.7 2.5 15.3 4.5 1.9 329.3 160.1 52.3

Histamine Histamine Putrescine Cadaverine Histamine Tyramine Histamine Tyramine Tryptamine Putrescine Phenylethylamine Cadaverine

1

654

4 1 8 1 88 7 359 1 601 8 36

519 186 931 356 291

Source

Bomke et al. (2009) Bauer (2004)

Smeˇlá et al. (2003)

characterised by an N—N = O functional group, NAs are N-nitroso derivatives of secondary amines, while NADs are N-nitroso derivatives of substitutes urea, amides, carbamates, guanidines and similar compounds. NAs and NADs are commonly formed by the reaction of nitrous acid with secondary amines and amines, respectively (Sung, 2004). NAs are formed in foods by nitrosation of secondary amines, where the main nitrosating agent is nitrous anhydride formed from nitrite. The formation by Rath and Reyes (2009) can be described by equations 19.1–19.3 as follows: NO−2 + H2O ↔ HNO2 + OH−

19.1

2HNO2 ↔ N2O3 + H2O

19.2

R1R2NH + N2O3 → R1R2N—N = O + HNO2

19.3

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

491

It is notable that formation of NAs is possible only from secondary amines. NAs formed from primary amines are unstable and are immediately decomposed to alcohols and nitrogen (equation 19.4), while tertiary amines cannot react at all (Honikel, 2008). R1NH2 + N2O3 → R1HN—N = O → ROH + N2

19.4

R1R2R3N + N2O3 − no nitrosation reaction

19.5

In general, NAs are stable in neutral and strongly alkaline environments, and are difficult to decompose once they are formed. Under UV radiation and strongly acidic conditions NA molecules are split and the NO group released as a result.

19.3.3 Formation of NAs The formation of NAs in meat and meat products is a complex process, and several factors and compounds can affect nitrosation reactions. Thus, NA content depends on such factors as: • • • • • •

residual nitrite content; the presence of catalysts and inhibitors of nitrosation; method of thermal treatment; time and intensity of thermal treatment; storage conditions; and the presence of microorganisms,

These factors are able to reduce nitrate to nitrite and degrade proteins to amino acids with subsequent decarboxylation and amine formation (Rath and Reyes, 2009). Smoking also involves components which play a part in N-nitrosamine formation processes. Pensabene and Fiddler (1983) proved that the formation of N-nitrosothiazolidine from either cysteine or cysteamine can occur during heating-smoking procedures when formaldehyde is formed during the thermal combustion of wood and generation of smoke and initiates an interaction.

19.3.4 Inhibition of NAs Attempts to reduce NA contents by the addition of various compounds were carried out by many research teams. Fiddler et al. (1973) reduced NDMA content by addition of sodium ascorbate and sodium erythorbate to frankfurters. Sen et al. (1976) proved that more effective inhibitors for NA formations are propyl gallate and L-ascorbyl palmitate. Bharucha et al. (1980) lowered NAs content in bacon by ascorbyl palmitate more effectively than sodium ascorbate or erythorbate but its efficacy decreased with storage time. Long-chain acetals of ascorbic acid resulted in a 93–98% reduction of nitrosamines in the fat released during cooking when streaked

© Woodhead Publishing Limited, 2011

492

Processed meats

on bacon slices. C16 ascorbyl acetal either with or without sodium erythorbate gave an 80–90% reduction of nitrosamine formation in fat under household frying conditions. Later, the same authors (Bharucha et al. 1985) inhibited the formation of NAs in bacon by the addition of antioxidant ethoxyquin. Ethoxyquin, dihydroethoxyquin and their analogues are potent inhibitors of nitrosamine formation in bacon, even at levels as low as 20 ppm. As exemplified by ethoxyquin in the case of nitrosopyrrolidine, they function by competing with proline for the available nitrosating species to form initially 1-nitrosoethoxyquin which rearranges to the 8-nitroso compound prior to oxidation by air to 8-nitroethoxyquin. The latter compound was isolated from ethoxyquin-treated bacon samples and also from the nitrosation of ethoxyquin with sodium nitrite or nitrosyl chloride. Later, Bharucha et al. (1986) proved that primary p-alkoxyanilines provide 89–100% inhibition while secondary ones show less efficiency equal to 82–93% inhibition. The effects of competitive C- and S-nitrosations on the formation of nitrosopyrrolidine were studied in a protein-based model (Massey et al., 1978). Ascorbic acid, cysteine and p-cresol were each shown to reduce the formation of nitrosopyrrolidine, in decreasing amounts, by competing with pyrrolidine for the available nitrite. A second pathway of nitrosopyrrolidine formation was found which may have involved transnitrosation by the protein-bound nitrite. Bharucha et al. (1979) studied the conditions and mechanism of N-nitrosopyrrolidine formation during bacon cooking. They showed evidence that N-nitrosopyrrolidine in cooked bacon arises via decarboxylation of N-nitroso proline which was most probably formed by radical nitrosation of free proline in pork belly. N-nitrosamine formation during frying of bacon occurs essentially, if not entirely, in the fat phase, after the bulk of the water is removed. a radical rather than an ionic mechanism. They also postulated that raw bacon is essentially free of volatile NAs and grilling produces fewer nitrosamines than frying. The amount of NAs in the fat released during cooking is roughly twice that in the rasher, and up to 62% of the NDMA and 32% of the total NPYR produced appear in the vapours. Nitrosation reaction in bacon occurs during frying largely after most of the water is expelled from the system. They concluded that the essential but probably not the only requirements for a potential anti-nitrosamine agent in bacon are: • • • •

ability to trap NO radicals; lipophilicity; non-steam volatility; and heat treatment up to 174 °C as a maximum frying temperature.

Byun et al. (2004) treated fermented salami by irradiation at 0, 5, 10 and 20 kGy and storage either under vacuum packaging or aerobic conditions. Significantly lower NA levels were observed in the vacuum-packed samples

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

493

than in the aerobic ones. Ahn et al. (2002) reported that the reduction state combined with the direct physical effect produced by irradiation in an anaerobic environment may change NO2− to NO, which is not a nitrosating agent. NO would stay in the gaseous state or change to other compounds by a further reaction. Rywotycki (2007) observed positive effects of sodium chloride or sodium ascorbate addition to meat on NA level in comparison with meat without the additives. Choi et al. (2006) considerably lowered NDMA content by chloroform extracts of Orostachys japonicus, which consisted of phenolic compounds and flavonoids which probably had a reducing effect to nitrous oxide. This is really of importance since processed meat technology employs numerous herb species to add taste and flavour to many value added meat products.

19.3.5 Analysis of NAs For analytical purposes, NAs are divided into volatile and non-volatile compounds. The volatile NAs are a group of relatively non-polar, lowmolecular weight compounds which can be removed from the food matrix by either atmospheric or vacuum steam distillation. Non-volatile NAs (polar, high-molecular weight compounds) can be isolated by extraction with acidified water alone or using organic solvent such as acetone, methanol and acetonitrile, respectively. A number of extraction and clean-up procedures for determining NAs in meat products have been described, including solvent extraction on a dry Celite column low temperature vacuum distillation, supercritical fluid extraction and solid-phase extraction. Most current methods require selective separation of analyte by multiple sample preparation treatments, including homogenisation, distillation, solvent extraction-partition, concentration and other clean-up steps (Andrade et al., 2005). The determination of volatile NAs in meat and meat products has been carried out by different analytical methods, including gas liquid chromatography (GLC) with selective thermal energy analyser and high resolution MS. Similarly low resolution MS can also be employed; however, there is a major necessity for thorough clean up procedure for samples when employing this technique. Regarding non-volatile NAs, HPLC is the most suitable method because there are sufficient detection systems such as specific thermal energy analyser and electrochemical detectors available. UV detectors also need a thorough clean-up procedure, and fluorescence detector usage is limited because very few NAs are fluorescent. Other separation techniques have been applied to NA analysis in the past such as solid-phase extraction–micellar electrokinetic chromatography (Sanches Filho et al., 2003). Analytic procedures of NA determination in foods including meat and meat products have been reviewed extensively. Many factors have been addressed such as effecting recovery, suitability of extraction procedures, choice of stationary

© Woodhead Publishing Limited, 2011

494

Processed meats

and mobile phases (Biaudet et al., 1996; Khalaf and Steinert, 2000; Sung, 2004; Rath and Reyes, 2009). 19.3.6 Occurrence of N-nitroso amines Normally, fresh meat is free of NAs. As already outlined, they are usually formed during curing and subsequent thermal treatment. Their content within meat products usually varies at a level of μg kg−1. Some general findings on NA content are shown in Table 19.4.

Table 19.4

Content of N-nitroso amines in meat products

Product

Sample no.

Average values (μg kg−1) Smoked meat Half-smoked 32 sausage Smoked 25 sausage Cooked 10 sausage Frankfurters 10 Salami 10 Ham 28 Bacon 12 Pork 33 Fried meat Pork 8 Mutton 10 Salami I 1 Salami II 1 Fried bacon 12 Cooked out 12 fat from fried bacon Range values (µg kg−1) 56 Sausages 395 Fried bacon

22

Cured meats

27

Dry cured bacon Ham and sausages

22 56

NDMA

NDEA

NPYR

NPIP

1.44

0.48

3.10

2.33

1.01

0.33

2.43

0.89

0.34

0.29

0.81

0.42

0.16 0.84 1.00 1.12 1.16

n.d. 0.67 0.37 0.65 0.40

0.48 0.93 3.73 2.04 7.48

n.d. 0.64 1.79 1.23 1.61

1.02 1.04 43.5 15.0 3.4 6.4

0.66 0.64 n.d. n.d. 1.0 0.6

10.23 2.58 n.d. n.d. 9.3 21.9

1.13 0.97 n.d. n.d.

0.01–0.08 0.5–12

– –

– 0.5–45

– –

–

–

7–139

–

–

2.6–22.3

–

n.d.–36 – 0.5–545.2

© Woodhead Publishing Limited, 2011

Source

Yurchenko and Mölder (2007)

Andrade et al. (2005) Sen at al. (1979)

Sen (1972) Spiegelhalder et al. (1980) Havery et al. (1976) Stephany and Schuller (1980) Fiddler et al. (1989) Park et al. (1998)

Heat and processing generated contaminants in processed meats

495

19.4 Heterocyclic amines (HAs) 19.4.1 Introduction Research on the carcinogenicity of heat-treated meat started in 1939 when the Swedish chemist Widmark found that extracts of fried horse meat induce cancer if applied to the skin of mice (Widmark, 1939). However, it took the next 40 years before Japanese scientists discovered a group of highly mutagenic compounds, classified as heterocyclic aromatic amines (HAs) from broiled and grilled meat and fish dishes (Wakabayashi and Sugimura, 1998). Many of these extremely mutagenic heterocyclic amines have been shown to be multi-site tumour inducers in long-term animal studies on rodents and monkeys. Studies on human cells in vitro have demonstrated that they are metabolised into bio-active compounds and form DNA adducts. The possible involvement of HAs in human cancer has recently been discussed (Totsuka et al., 2006). Up until recently, around 20 different mutagenic and/ or HAs have been identified (Jägerstad et al., 1998).

19.4.2 Characterisation of HAs HAs can be divided into two groups: polar compounds mainly of the imidazoquinoline (e.g. IQ), imidazoquinoxaline (IQx), and imidazopyridine types and non-polar compounds which have a common pyridoindole or pyridoimidazole group. The most common HAs and their abbreviations are shown in Table 19.5. The terms polar and non-polar refer not only to the order of elution in reversed-phase chromatography but also to the fluorescence of the substances. The non-polar HAs, including PhIP, fluoresce very strongly in polar solvents. The polar HAs are formed from amino acids and creatinine in the presence or absence of carbohydrates. Creatinine provides the imidazole ring for the condensed aromatic amines, in its absence no IQ and IQx-type HAs can be formed (Murkovic, 2007).

19.4.3

Formation of imidazoquinoline, imidazoquinoxaline and imidazopyridine compounds This group is sometimes termed thermal mutagens, since they have been shown to be formed at temperatures used during ordinary thermal procedures (Hatch et al., 1988). The Maillard reaction has been reported to play an important role in the formation of HAs. It was suggested that creatine, free amino acids and hexoses present in raw meat are precursors of the IQ and IQx compounds, and outlined a pathway for their formation (Jägerstad et al., 1983). It was postulated that creatine formed the amino-imidazo part of the molecule by cyclisation and water elimination. The remaining parts of the IQ and IQx compounds were assumed to arise from Strecker degradation products, e.g. pyridines or pyrazines, formed in the Maillard reaction

© Woodhead Publishing Limited, 2011

496

Processed meats

Table 19.5

Heterocyclic amines, names and abbreviations

Group

Name of compound

Abbreviation

Quinolines

2-amino-3-methylimdazo[4,5-f]quinoline 2-amino-3,4-dimethylimdazo[4,5-f]quinoline

IQ MeIQ

Quinoxalines

2-amino-3-methylimdazo[4,5-f]quinoxaline 2-amino-3,8-dimethylimdazo[4,5-f]quinoxaline 2-amino-3,4,8-trimethylimdazo[4,5-f]quinoxaline 2-amino-3,7,8-trimethylimdazo[4,5-f]quinoxaline 2-amino-3,4,7,8-tetramethylimdazo[4,5-f] quinoxaline 2-amino-4-hydroxymethyl-3,8-dimethylimidazo [4,5-f]quinoxaline 2-amino-1,7,9-trimethylimidazo[4,5-g] quinoxaline

IQx MeIQx 4,8-DiMeIQx 7,8-DiMeIQx TriMeIQx

2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine 2-amino-1-methyl-6-[4-hydroxyphenyl)imidazo [4,5-b]pyridine dimethylimidazopyridine trimethylimidazopyridine 2-amino-1,6-dimethylfuro[3,2-e]imidazo[4,5-b] pyridine

PhIP

3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole 3-amino-1-methyl-5H-pyrido[4,3-b]indole 2-amino-6-methyl-dipyrido[1,2-a:3′,2′-d] imidazole 2-amino-dipyrido[1,2-a:3′,2′-d]imidazole 1methyl-9H-pyrido[4,3-b]indole (Harman) 9H-pyrido[4,3-b]indole (Norharman) 2-amino-9H-dipyrido[2,3-b]indole 2-amino-3-methyl-9H-dipyrido[2,3-b]indole

Trp-P-1 Trp-P-2 Glu-P-1

Pyridines

Pyridoimidazoles and indoles

Benzoxazines

4′-OH-PhIP DMIP TMIP IFP

Glu-P-2 H NH AαC MeAαC

2-amino-3-methylimidazo[4,5-f]-4H-1, 4-benzoxazine 2-amino-3,4-dimethylimidazo[4,5-f]-4H-1, 4-benzoxazine

Furopyridines Other structures

4-CH2OH-8MeIQx 7,9-DiMeIgQx

MeIFP 3,4-cyclopentenopyrido-[3,2-a]carbazole 4-amino-6-methyl-1H2,5,10,10btetraazafluoranthene 2-amino-5-phenylpyridine

Lys-P-1 Orn-P-1 Phe-P-1

between hexoses and amino acids. Milic et al. (1993) suggested that the initial step in the formation of MeIQx and DiMeIQx was dependent on the kinetics of the Maillard and Strecker reactions, with the formation of pyridine and pyrazine-free radicals, and finally the stabilisation of the free

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

497

radicals, giving pyridine and pyrazine derivatives, which react with creatinine.

19.4.4 Formation of pyridoindole and pyridoimidazole compounds These compounds are sometimes referred to as pyrolytic mutagens, since they were first isolated from smoke condensates collected either from cigarettes or from pyrolysed single amino acids (e.g. tryptophan, glutamic acid, lysine, phenylalanine, ornithine or creatine) or from pyrolysed proteins like casein, albumin, gluten or soybean globulin. This was the first class among the mutagenic HAs that was discovered, mainly during the years 1975–1980. The HAs in this class usually have an exocyclic amino group and sometimes also an exocyclic methyl group attached to a pyridine ring linked either to an indole or an imidazole moiety (Jägerstad et al., 1998).

19.4.5 Factors affecting HAs formation and elimination The formation of HAs depends, of course, on the presence and content of precursors, enhancers, inhibitors, time, temperature, water activity and pH (Knize and Felton, 2005). Domestic frying and oven roasting often take place at temperatures below 225 °C. The formation of MeIQx in fried meat has been shown to increase with cooking time and temperature in the intervals 150–230 °C and 2–10 min (Knize et al., 1994). Abdulkarim and Smith (1998) studied the combination of time and temperature on HA formation in various meat products. While at 150 °C they did not observe any HA formation, at 230–240 °C the formation of five HAs was observed (see Table 19.6). Thiebaud et al. (1995) detected high contents of HAs in smoke condensates to be formed during 200 °C thermal treatment such as 3 ng g−1 from fried bacon, 0.37 ng g−1 from fried beef and 0.177 ng g−1 from fried soy-based food. On the other hand, lowering the pan temperature and turning the beef patties frequently can greatly reduce the formation of HAs and to ensure a product that is safer for human consumption (Salmon et al., 2000). Interesting information was discovered recently about the possibility of destroying HAs in the digestive tract using intestinal bacteria (Vanhaecke et al., 2008).

19.4.6 Analysis of HAs HPLC is the dominant method for the determination of HAs using base inactivated reversed phase columns. These special phases are necessary, because the highly polar part of the molecule (the aminoimidazo moiety) results in substantial tailing of the peaks (Murkovic, 2007). A detailed overview of the columns previously used for analysis of HAs has been published by Galceran and Puignou (2006). Jautz and Morlock (2006) used TLC for

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

9.28 10.54

✗

✗

✗ ✗

✗ nd

✗ nd

nd nd nd nd 7.34

✗ ✗

✗ ✗

nd nd nd ✗ ✗

✗ ✗ ✗ ✗ ✗

✗ ✗ ✗ ✗ ✗

nd – not detected, ✗ – not determined.

Beef liver Lamb kidney Beef tongue Pork meat – collar Pork meat – collar-gravy Pork meat – chop Pork meat – chop-gravy

MeIQ

0–2 0–2 0–15 0–6

IQ

0–3.0

0.2–33.1

1.4–11.3

✗ ✗ 1.74 1.62

nd 1.52

✗ ✗

nd 0–0.1 0.3–3.1 0–0.08 0–0.01 0.11–0.12 0.32–0.55 0.04–0.21 0–0.02 0.02–0.03 0.2–0.33 nd 4.59 ✗ ✗ nd 1.87 ✗ ✗

nd

1.0–4.8

✗ ✗

1.87–8.87 0.45–0.50 0.61–0.83 ✗ ✗

✗ ✗

nd nd nd ✗ ✗

2.1–11.3 ✗

✗ ✗

nd nd nd ✗ ✗

✗

✗ ✗ ✗ ✗ ✗ ✗ 2.42–21.2 0–0.33 0–0.35

0.5–1.8 ✗ 0.5–0.7 ✗ 1.73–7.12 1.9–5-9

✗ ✗

✗ ✗ ✗ ✗ ✗

0–1 0–5

Jägerstad et al. (1998)

Source

✗ ✗

nd nd nd ✗ ✗

✗

✗ ✗ nd

0.1–0.13 0.07–0.13

Janoszka et al. (2009)

Keating et al. (2000) Toribio et al. (2007) Jautz et al. (2008) Khan et al. (2009)

0.015–0.043 Abdulkarim and Smith 0.08–0.2 (1998) 0.06 0.02–0.4 0.03

0–1 0

Trp-P-1 Trp-P-2

0.5–2.2 0.2–0.8 1.0 0.2–0.3 0–2.44 0.28–1.27

✗ ✗ ✗ ✗ ✗

0–20 0–3

AαC

0.57–0.79 ✗ 1.98–4.2 ✗

0–1.12 0–1.42 0–3.08 0–1.21 0–1.52

✗ ✗

✗ ✗

0–0.4 0–0.39 0–0.42 0.39 0–0.79 0–0.084 0.22 0–0.22 0.3–0.31 0–0.39

0–35 0–10

NH

H

0.09–0.27 0.10–0.15 0.69–1.27 0.5–1.16

✗ ✗ ✗ ✗ ✗

0–5 0–9

4,8PhIP DiMeIQx

0.35–0.43 ✗ 0.4–0.8 ✗

0–0.63 0–0.72 0–0.57 0–0.13 0.43–0.47

0–10 0–80

MeIQx

Findings of heterocyclic amines (μg kg−1) in meat products

Red meat Meat extract, pan residues Fried pork sausage Bratwurst Fried Italian sausage Fried smoked sausage Barbecued pork sausage Bratwurst Barbecued Italian sausage Hamburger Steak Beef steaks (four samples) Fried meat

Table 19.6

Heat and processing generated contaminants in processed meats

499

analysis of heterocyclic aromatic amines. The meat extract was separated on silica gel 60 high performanceTLC plates with mixtures of diethyl ether and methanol as mobile phases. By use of a newly developed device the spot was extracted from the TLC plate and transferred to electrospray ionisation–mass spectroscory (ESI–MS). This system was tested for Harman with a limit of quantification of below 35 pg on the plate (Luftman et al. 2007). Because of the complex matrix and low contents, sensitive and selective detection methods are necessary to obtain reliable results. For this reason, mass-selective detection is now used as a standard technique. Galceran and Puignou (2006) showed that triple quadrupole and time of flight mass spectrometry (TOF-MS) are sensitive and selective enough to obtain credible results. When one or more fragmentation and/or isolation cycles are used in the MS experiments, additional structural information can be obtained, increasing the reliability of the results. The triple quadrupole is significantly more sensitive when daughter ions are analysed. The advantage of the triple quadrupole is not only the good sensitivity but also a reduction of the matrix and usually, exclusion of coeluting peaks when analysing HAs, which results in a better signal-to-noise ratio (Galceran and Puignou, 2006).

19.4.7 Occurrence of HAs In the past there has been a lot of analysis of HA content in various meat matrices, but the results obtained are not definitive, due to the fact that formation takes place at various physical conditions and is affected by matrix effects. Moreover, HAs are numerous and authors in their studies did not always determine the same compounds. In spite of this, some findings are compiled and shown in Table. 19.6.

19.5 Conclusions During the production of meat products, meat undergoes various treatments such as brining, smoking, ripening, drying, cooking, frying and storage. These technological operations are applied to increase palatability, attractiveness, digestibility and safety of a specific product, in order to satisfy increased consumer demand for all these criteria. However, these operations are also responsible for formation of compounds which may threaten human health. This chapter deals with such contaminants as polycyclic aromatic hydrocarbons, N-nitroso compounds, biogenic amines and heterocyclic amines. As proven by numerous studies, these compounds can be effectively decreased or even eliminated via detailed knowledge about these technological processes, control of the parameters affecting their formation, and understanding of the role of the precursors to these compounds in the treatment process. While some aspects of the problem are

© Woodhead Publishing Limited, 2011

500

Processed meats

already clear and result in considerable lowering of hazardous substances in meat products (e.g. the replacement of traditional procedures of smoking with liquid smoke flavours, the application of suitable plastic packages, the addition of antioxidants to brine), other aspects are still open to speculation (e.g. the formation of heterocyclic and biogenic amines). Further systematic research into the chemistry and technology of meat processing is necessary in order to minimise the occurrence of these compounds in meat products worldwide.

19.6 Acknowledgement This contribution is the result of the project implementation ‘Centre of Excellence for Contaminants and Microorganisms in Food’ supported by the Research & Development Operational Programme funded by the ERDF.

19.7 References and further reading abdulkarim b g and smith j s (1998), ‘Heterocyclic amines in fresh and processed meat products’, J Agric Food Chem, 46, 4680–4687. ahn h j, yook h s, rhee m s, lee c h, cho y j and byun m w (2002), ‘Reduction of carcinogenic N-nitrosamines and residual nitrite in model system sausage by irradiation’, J Food Sci, 67, 1370–1373. andelman j b and suess m j (1970), ‘PAH in the water environment’, Bull WHO, 43, 479–508. andrade r, reyes f g r and rath s (2005), ‘A method for the determination of volatile N-nitrosamines in food by HS-SPME-GC-TEA’, Food Chem, 91, 173–179. aoac (1995), Official Method 973.30. 16th ed. AOAC International, Arlington, 48-11995. bardócz s (1993), ‘The role of dietary polyamines’, Eur J Clin Nutr, 47, 683–690. bartle k d (1991), ‘Analysis and occurrence of polycyclic aromatic hydrocarbons in food’, in Creaser C and Purchase R, Food Contaminants, Sources and Surveillance, Cambridge, Royal Society of Chemistry, 41–60. bauer f (2004), ‘Residues associated with meat production’, in Jensen, W K, Devine C and Dikeman K, Encyclopedia of Meat Sciences, London, Elsevier, 1187–1192. bharucha k r, cross c k and rubin l j (1979), ‘Mechanism of N-nitrosopyrrolidine formation in bacon’, J Agric Food Chem, 27, 63–69. bharucha k r, cross c k and rubin l j (1980), ‘Long-chain acetals of ascorbic and erythorbic acids as antinitrosamine agents for bacon’, J Agric Food Chem, 28, 1274–1281. bharucha k r, cross c k and rubin l j (1985), ‘Ethoxyquin, dihydroethoxyquin, and analogues as antinitrosamine agents for bacon’, J Agric Food Chem, 33, 834–839. bharucha k r, cross c k and rubin l j (1986), ‘p-Alkoxyanilines as antinitrosamine agents for bacon’, J Agric Food Chem, 34, 814–818. biaudet h, pignatelli b and bebry g (1996), ‘N-Nitroso compounds’, in Nollet, L M L, Handbook of Food Analysis, New York, Marcel Dekker Inc., 1603–1640.

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

501

binnemann p h (1979), ‘Benz(a)pyrene in Fleischerzeugnissen’, Z Lebensm Unters Forsch, 169, 447–452. bodmer s, imark c and kneubuohl m (1999), ‘Biogenic amines in foods: histamine and food processing’, Inflam Res, 48, 296–300. bomke s, seiwert b, dudek l, effkemann s and karst u (2009), ‘Determination of biogenic amines in food samples using derivatization followed by liquid chromatography/mass spectrometry’, Anal Bioanal Chem, 393, 247–256. bordas m, moyano e, puignou l and galceran m t (2004), ‘Formation and stability of heterocyclic amines in a meat flavour model system, effect of temperature, time and precursors’, J Chrom B, 802, 11–17. bover-cid s, izquierdo-pulido m and vidal-carou m c (2000), ‘Influence of hygienic quality of raw materials on biogenic amine production during ripening and storage of dry fermented sausages’, J Food Protect, 63, 1544–1550. bover-cid s, hugas m, izquierdo-pulido m and vidal-carou m c (2001), ‘Amino acid decarboxylase activity of bacteria isolated from fermented pork sausages’, Int J Food Microbiol, 66, 185–189. bover-cid s, hernández-jover t, miguélez-arrizado m j and vidal-carou m c (2003), ‘Contribution of contaminant enterobacteria and lactic acid bacteria to biogenic amine accumulation in spontaneous fermentation of pork sausages’, Eur Food Res Technol, 216, 477–482. brink b t, damink c, joosten h and huis in’t veld j (1990), ‘Occurrence and formation of biologically active amines in foods’, Int J Food Microbiol, 11, 73–84. byun m w, ahn h j, kim j h, lee j w, yook h s and han s b (2004), ‘Determination of volatile N-nitrosamines in irradiated fermented sausage by gas chromatography coupled to a thermal energy analyzer’, J Chrom A, 1054, 403–407. cejpek k, hajsˇlová j, jehlicˇková z and merhaut j (1995), ‘Simplified extraction and cleanup procedure for the determination of PAHs in fatty and protein rich matrices’, Int J Environ Anal Chem, 61, 65–80. chen j and chen s (2005), ‘Removal of polycyclic aromatic hydrocarbons by low density polyethylene from liquid model and roasted meat’, Food Chem, 90, 461–469. choi s y, chung m j, seo w d, shin j h, shon m y and sung n j (2006), ‘Inhibitory effects of Orostachys japonicus extracts on the formation of N-nitrosodimethylamine’, J Agric Food Chem, 54, 6075–6078. Commission Directive 88/388/EEC of 22 June 1988 on the approximation of the laws of the Member States relating to flavourings for use in foodstuffs and to source materials for their production. OJ L184, 15.07.1988, p. 61. Commission Directive 2005/10/EC of 4 February 2005 laying down the sampling methods and the methods of analysis for the official control of the levels of benzo(a)pyrene in foodstuffs. OJ L34, 8.02.2003, p. 15. Commission Recommendation 2005/108/EC of 4 February 2005 on the further investigation into the levels of polycyclic aromatic hydrocarbons in certain foods. OJ L34, 8.02.2003, p. 43. Commission Regulation 2065/2003/EC of 10 November 2003 on smoke flavourings used or intended for use in or on foods. OJ L309, 26.11.2003, p. 1. Commission Regulation 1881/2006/EC of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. OJ L364, 20.12.2006, p. 5. Commission Regulation 2073/2005/EC of 15 November 2005 on microbiological criteria for foodstuffs. OJ L338, 22.12.2005, p. 1. dennis m j, massey r c, mcweeny d j, larsson b, eriksson a and sahlberg g (1984), ‘Comparison of capillary gas chromatographic and high-performance liquid chromatographic method of analysis for polycyclic aromatic hydrocarbons in food’, J Chrom, 285, 127–133.

© Woodhead Publishing Limited, 2011

502

Processed meats

djinovic j, popovic a and jira w (2008a), ‘Polycyclic aromatic hydrocarbons (PAHs) in traditional and industrial smoked beef and pork ham from Serbia’, Eur Food Res Technol, 227, 1191–1198. djinovic j, popovic a and jira w (2008b), ‘Polycyclic aromatic hydrocarbons (PAHs) in different types of smoked meat products from Serbia’, Meat Sci, 80, 449–456. dobríková e and sveˇtlíková a (2007), ‘Occurrence of benzo[a]pyrene in some foods of animal origin in the Slovak Republic’, J Food Nutr Res, 46, 181–185. eerola s, sagues a x r, lilleberg l and aalto h (1997), ‘Biogenic amines in dry sausages during shelf-life storage’, Z Lebensm Unters Forsch, 205, 351–355. ender f and ceh l (1971), ‘Conditions and chemical reaction mechanisms by which nitrosamines may be formed in biological products with reference to their possible occurrence in food products’, Z Lebensm Unters Forsch, 145, 133–142. ender f, harvey g n, madsen r, ceh l and helgebostad a (1967), ‘Studies on conditions under which N-nitrosodimethylamine is formed in herring meal produced from nitrite-preserved herring. The risk of using nitrite uncritically as a preservative agent’, Z Tierphysiol Tiererehnahr Futtermitt, 22, 181–189. fiddler w, pensabene j w, kushnir i and piotrowski e g (1973), ‘Effect of frankfurter cure ingredients on N-nitrosodimethylamine formation in a model system’, J Food Sci, 38, 714–715. fiddler w, pensabene j w, gates r a and foster j m (1989), ‘Investigations on N-nitrosopyrrolidine in dry-cured bacon’, J Assoc Off Anal Chem, 72, 19–22. fretheim k (1976), ‘Carcinogenic PAH in Norwegian smoked meat sausages’, J Agric Food Chem, 24, 976–979. freud h a (1937), ‘Clinical manifestations and studies in parenchymous hepatitis’, Ann Inter Med, 10, 1144–1155. galceran m t and puignou l (2006) ‘Latest developments in the analysis of heterocyclic amines in cooked foods’, in Skog K and Alexander J, Acrylamide and other Hazardous Compounds in Heat-Treated Foods, Cambridge, Woodhead Publishing, 68–116. gomaa e a, gray i j, rabie s, lopez-bote c and booren a m (1993), ‘Polycyclic aromatic hydrocarbons in smoked food products and commercial liquid smoke flavourings’, Food Addit Contam, 10, 503–521. grimmer g and böhnke h (1975), ‘Polycyclic aromatic hydrocarbon profile analysis of high protein foods, oils and fats by gas chromatography’, J Assoc Off Anal Chem, 58, 725–733. guillén m d (1994), ‘Polycyclic aromatic compounds: extraction and determination in food’, Food Addit Contam, 11, 669–684. halász a, baráth a, simon-sarkádi l and holzapfel w (1994), ‘Biogenic-amines and their production by microorganisms in food’, Trends Food Sci Technol, 5, 42–49. hatch f t, felton j s and knize m g (1988), ‘Mutagens formed in foods during cooking’, Pharmacology, 2, 222–228. havery d c, klin d a, miletta e m, joe j l and fazio t f (1976), ‘Survey of food products for volatile N-nitrosamines’, J Assoc Off Anal Chem, 59, 540–546. hernández-jover t, izquierdo-pulido m, veciana-nogus m t and vidal-carou m c (1996), ‘Biogenic amine sources in cooked cured shoulder pork’, J Agric Food Chem, 44, 3097–3101. hernández-jover t, izquierdo-pulido m, veciana-nogus m t, marin-font a and vidal-carou m c (1997), ‘Biogenic amine and polyamine contents in meat and meat products’, J Agric Food Chem, 45, 2098–2102. honikel k o (2008), ‘The use and control of nitrate and nitrite for the processing of meat products’, Meat Sci, 78, 68–76. howard j w and fazio t (1969), ‘A review of polycyclic aromatic hydrocarbons in foods’, J Agric Food Chem, 17, 527–531.

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

503

jägerstad m, laser reuterswärd a, öste r, dahlqvist a, olsson k, grivas s, nyhammar t (1983), ‘Creatinine and Maillard reaction products as precursors of mutagenic compounds formed in fried beef’, in Waller G and Feather M, The Maillard Reaction in Foods and Nutrition, Washington DC, American Chemical Society, 507–519. jägerstad m, skog k, arvidsson p and solyakov a (1998), ‘Chemistry, formation and occurrence of genotoxic heterocyclic amines identified in model systems and cooked foods’, Z Lebensm Unters Forsch, 207, 419–427. janoszka b, błaszczyk u, damasiewicz-bodzek a and, sajewicz m (2009), ‘Analysis of heterocyclic amines (HAs) in pan-fried pork meat and its gravy by liquid chromatography with diode array detection’, Food Chem, 113, 1188–1196. jautz u and morlock g (2006), ‘Efficacy of planar chromatography coupled to (tandem) mass spectrometry for employment in trace analysis’, J Chromatogr A, 1128, 244–250. jautz u, gibis m and morlock g e (2008), ‘Quantification of heterocyclic aromatic amines in fried meat by HPTLC/UV-FLD and HPLC/UV-FLD: a comparison of two methods’, J Agric Food Chem, 56, 4311–4319. jefca (1987), Report of the Joint FAO/WHO Expert Commission on Food Additives No. 31, 759. jira w (2004), ‘A GC/MS method for the determination of carcinogenic polycyclic aromatic hydrocarbons (PAH) in smoked meat products and liquid smokes’, Eur Food Res Technol, 218, 208–212. joe f l, salemme j and fazio t (1984), ‘Liquid chromatographic determination of trace residues of polynuclear aromatic hydrocarbons in smoked foods’, J Assoc Off Anal Chem, 67, 1076–1082. kangsadalampai k butryee c and manoonphol k (1997), ‘Direct mutagenicity of the polycyclic aromatic hydrocarbon-containing fraction of smoked and charcoalbroiled foods treated with nitrite in acid solution’, Food Chem Toxicol, 35, 213–218. kaniou i, samouris g, mouratidou t, eleftheriadou a and zantopoulos n (2001), ‘Determination of biogenic amines in fresh unpacked and vacuum-packed beef during storage at 4 °C′, Food Chem, 74, 515–519. keating g a, sinha r, layton d, salmon c p, knize m g, bogen k t, lynch c and alavanja m (2000), ‘Comparison of heterocyclic amine levels in home-cooked meats with exposure indicators (United States)’, Canc Cause Contr, 11, 731–739. khalaf h and steinert j (2000), ‘Determination of N-nitroso compounds in foods and beverages’, in Nollet, L M L, Food Analysis by HPLC, New York, Marcel Dekker Inc, 939–964. khan m r, bertus l m, busquets r and puignou l (2009), ‘Mutagenic heterocyclic amine content in thermally processed offal products’, Food Chem, 112, 838– 843. knize m g and felton j s (2005), ‘Formation and human risk of carcinogenic heterocyclic amines formed from natural precursors in meat’, Nutr Rev, 63, 158–165. knize m g, dolbeare f a, carroll k l, moore d h i and felton j s (1994), ‘Effect of cooking time and temperature on the heterocyclic amine content of fried beef patties’, Food Chem Toxicol, 32, 595–603. larsson b k, sahlberg g p, eriksson a t and busk l a (1983), ‘Polycyclic aromatic hydrocarbons in grilled food’, J Agric Food Chem, 31, 867–873. latorre-moratalla m l, veciana-nogues t, bover-cid s, garriga m, aymerich t, zanardi e, ianieri a, fraqueza m j, patarata l, drosinos e h, laukova a, talon r and vidal-carou m c (2008), ‘Biogenic amines in traditional fermented sausages produced in selected European countries’, Food Chem, 107, 912–921.

© Woodhead Publishing Limited, 2011

504

Processed meats

law r j, kelly c, baker k, jones j, mcintosh a d and moffat c f (2002), ‘Toxic equivalency factors for PAH and their applicability in shellfish pollution monitoring studies’, J Environ Monit, 4, 383–388. lawrence j f and weber d f (1984), ‘Determination of polycyclic aromatic hydrocarbons in some Canadian commercial fish, shellfish, and meat products by liquid chromatography with confirmation by capillary gas chromatography–mass spectrometry’, J Agric Food Chem, 32, 789–794. lintas c and de matthaeis m c (1979), ‘Determination of benzo(a)pyrene in smoked, cooked and toasted food products’, Food Cosmet Toxicol, 17, 325–328. luftmann h, aranda m and morlock g (2007), ‘Automated interface for hyphenation of planar chromatography with mass spectrometry’, Rapid Commun Mass Spectrom, 21, 3772–3776. maga j a (1987), ‘The flavor chemistry of wood smoke’, Food Rev Int, 3, 139–183. massey r c, crews c, davies d and mcweeny d j (1978), ‘A study of the competitive nitrosations of pyrrolidine, ascorbic acid, cysteine and p-cresol in a protein-based model system’, J Sci Food Agric, 29, 815–821. milic b l, djilas s m and canadanovic-brunet j m (1993), ‘Synthesis of some heterocyclic amino-imidazoazarenes’, Food Chem, 46, 273–276. mottier p, parisod v and turesky r j (2000), ‘Quantitative determination of polycyclic aromatic hydrocarbons in barbecued meat sausages by gas chromatography coupled to mass spectrometry’, J Agric Food Chem, 48, 1160–1166. murkovic m (2007), ‘Analysis of heterocyclic aromatic amines’, Anal Bioanal Chem, 389, 139–146. nisbet i c t and la goy p k (1992), ‘Toxic equivalency factors (TEFS) for polycyclic aromatic hydrocarbons’, Reg Toxicol Pharmacol, 16, 290–300. nout m j r (1994), ‘Fermented foods and food safety’, Food Res Int, 27, 291–298. önal a (2007), ‘Current analytical methods for the determination of biogenic amines in foods’, Food Chem, 103, 1475–1486. parente e, matuscelli m, gadrini f, grieco s, crudele m a and suzzi g (2001), ‘Evolution of microbial populations and biogenic amines production in dry sausages produced in southern Italy’, J Appl Microbiol, 90, 882–891. park k r, lee s j, shin s j, kim j g and sung n j (1998), ‘The formation of N-nitrosamine in commercial ham and sausage’, J Food Hyg Safety, 13, 400–405. pensabene j w and fiddler (1983), ‘N-Nitrosothiazolidine in cured meat products’, J Food Sci, 48, 1870–1871. potthast k (1978), ‘Smoking methods and their effect on the conten of 3,4-benzpyrene and other constituents of smoke in smoked meat products’, Fleischwirtschaft, 58, 371–375. purcaro g, moret and conte l s (2009), ‘Optimisation of microwave assisted extraction (MAE) for polycyclic aromatic hydrocarbon (PAH) determination in smoked meat’, Meat Sci, 81, 275–280. rath s and reyes f g r (2009), ‘Nitrosamines’, in Nollet L M L and Toldrá F, Handbook of Processed Meats and Poultry Analysis, New York, CRC Press, 687–705. räuter w (1997), ‘Content of benzo(a)pyrene in smoked foods, Ernährung, 21, 447–448. roda a, simoni p, ferri e, girotti s, ius a, rauch p, poplstein m, pospisil m, pipek p, hochel i and fukal l (1999), ‘Determination of PAHs in various smoked meat products and different samples by enzyme immunoassay’, J Sci Food Agric, 79, 58–62. rywotycki r (2007), ‘The effect of baking of various kinds of raw meat from different animal species and meat with functional additives on nitrosamine contamination level’, Food Chem, 101, 540–548.

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

505

salmon c p, knize m g, panteleakos f n, wu r w, nelson d o and felton j s (2000), ‘Minimization of heterocyclic amines and thermal inactivation of Escherichia coli in fried ground beef, J Nat Can Ins, 92, 1773–1778. sanches filho p j, rios a, valcarcel m, zanin k d and caramao e b (2003), ‘Determination of nitrosamines in preserved sausages by solid-phase extraction– micellar electrokinetic chromatography’, J Chrom A, 985, 503–512. scanlan r a (1983), ‘Formation and occurrence of nitrosamines in foods’, Cancer Res, 43, 2435–2440. sen n p (1972), ‘The evidence for the presence of dimethylnitrosamine in meat products’, Food Cosmet Toxicol, 10, 219–223. sen n p, donaldson b, seaman s, iyengar j r and miles w f (1976), ‘Inhibition of nitrosamine formation in fried bacon by propyl gallate and L-ascorbyl palmitate’, J Agric Food Chem, 24, 397–401. sen n p, seaman s and miles w f (1979), ‘Volatile nitrosamines in various cured meat products: effect of cooking and recent trends’, J Agric Food Chem, 27, 1354–1357. shalaby a r (1994), ‘Separation, identification and estimation of biogenic amines in foods by thin-layer chromatography’, Food Chem, 49, 305–310. sikorski z e (2004), ‘Traditional smoking’, in Jensen, W K, Devine C and Dikeman K, Encyclopedia of Meat Sciences, London, Elsevier, 1265–1272. silla santos m h (1996), ‘Biogenic amines: their importance in foods’, Int J Food Microbiol, 29, 213–231. sˇimko p (1991), ‘Changes of benzo[a]pyrene content in smoked fish during storage’, Food Chem, 40, 293–300. sˇimko p (2002), ‘Determination of polycyclic aromatic hydrocarbons in smoked meat products and liquid smoke flavourings by gas chromatography and high pressure liquid chromatography’, J Chrom B, 770, 3–18. sˇimko p (2005), ‘Factors affecting elimination of polycyclic aromatic hydrocarbons in smoked meat foods and liquid smoke flavours’, Mol Nutr Food Res, 49, 637–647. sˇimko p and bruncková b (1993), ‘Lowering of polycyclic aromatic hydrocarbons in liquid smoke flavour by sorption into polyethylene packaging’, Food Addit Contam, 10, 257–263. sˇimko p, dubravicky´ j and smirnov v (1989), ‘Effect of smoke technology on benzo(a) pyrene content in smoked meat products’, Potr Veˇdy, 7, s.59–63. sˇimko p gombita m and karovicˇová j (1991), ‘Determination and occurrence of benzo(a)pyrene in smoked meat products’, Nahrung/Food, 35, 103–104. sˇimko p, gergely sˇ, karovicˇová j, drdák m and knežo j (1993), ‘Influence of cooking on benzo[a]pyrene content in smoked sausages’, Meat Sci, 34, 301– 309. sˇimko p, sˇimon p, khunová v, bruncková b and drdák m (1994), ‘Kinetics of polycyclic aromatic hydrocarbon sorption from liquid smoke flavor into low density polyethylene packaging’, Food Chem, 50, 65–68. skog k, johansson m a e and jägerstad m i (1998), ‘Carcinogenic heterocyclic amines in model systems andcooked foods – A review on formation, occurrence and intake’, Food Chem Toxicol, 36, 879–896. smeˇlá d, pechová p, komprda t, klejdus b and kubánˇ v (2003), ‘Liquid chromatographic determination of biogenic amines in a meat product during fermentation and long-term storage’, Czech J Food Sci, 21, 167–175. spiegelhalder b, eisenbrand g and preussmann r (1980), ‘Volatile nitrosamines in food’, Oncology, 37, 211–216. stephany r w and schuller p l (1980), ‘Daily dietary intakes of nitrate, nitrite and volatile N-nitrosamines in The Netherlands using the duplicate portion sampling technique’, Oncology, 37, 203–210.

© Woodhead Publishing Limited, 2011

506

Processed meats

stijve t and hischenhuber c (1987), ‘Simplified determination of benzo(a)pyrene and other aromatic hydrocarbons in various food materials by HPLC and TLC’, Deutsch Lebensm Rundsch, 83, 276–282. strmisková g, sˇimko p, holotík sˇ, dubravicky´ j and smirnov v (1987) ‘Effect of aromatisation by various smoke procedures on carbonyl content in Fine salami’, Bull Food Res, 26, 11–20. stumpe-viksna i, bartkevicˇ v, kukare a and morozovs a (2008), ‘Polycyclic aromatic hydrocarbons in meat smoked with different types of wood’, Food Chem, 110, 794–797. sung n (2004), ‘N-nitroso compounds in food’, in Nollet L M L, Handbook of Food Analysis, Dekker/CRC Press, New York, 1403–1448. tamakawa k (2004), ‘Polycyclic aromatic hydrocarbons in food’, Nollet L M L, Handbook of Food Analysis, New York, Marcel Dekker, 1449–1483. tamim n m, bennett l w, shellem t a and doerr j a (2002), ‘High performance liquid chromatographic determination of biogenic amines in poultry carcasses’, J Agric Food Chem, 50, 5012–5015. telling g m, bryce t a and althorpe j (1971), ‘Use of vacuum distillation and gas chromatography – mass spectrometry for determination of low levels of volatile nitrosamines in meat products’, J Agric Food Chem, 19, 937–940. thiebaud h p, knize m g, kuzmicky p a, hsieh d p and felton j s (1995), ‘Airborne mutagens produced by frying beef, pork and a soy-based food’, Food Chem Toxicol, 33, 821–828. toribio f, busquets r, puignou l and galceran m t (2007), ‘Heterocyclic amines in griddled beef steak analysed using a single extract clean-up procedure’, Food Chem Toxicol, 45, 667–675. tóth l and blaas w (1972), ‘Einfluss der Räeuchertechnologie auf den Gehalt von geraeucherten Fleischwaren an cancerogenen Kohlenwasserstoffen. II. Einfluss der Glimmtemperatur des Holzes sowie der Kuehlung, Waesche und Filtration des Räeucherrauches’, Fleischwirtschaft, 52, 1419–1422. tóth l and potthast k (1984) ‘Chemical aspects of the smoking of meat and meat products’, in Chichester C O, Mrak E M and Schweigert B S, Advances in Food Research, vol. 29, Academic Press Inc, Elsevier, 87–158. totsuka y, nishigaki r, sugimura t and wakabayashi k (2006), The possible involvement of mutagenic and carcinogenic heterocyclic amines in human cancer, in Skog K and Alexander J, Acrylamide and other Hazardous Compounds in Heattreated Foods, Cambridge,Woodhead Publishing, 296–327. vanhaecke l, knize m g, noppe h, brabander h de, verstraete w and wiele t van de (2008), Intestinal bacteria metabolize the dietary carcinogen 2-amino-1methyl-6-phenylimidazo[4,5-b]pyridine following consumption of a single cooked chicken meal in humans, Food Chem Toxicol, 46, 140–148. veciana nogue m t, marine font a and vidal carou m c (1997), ‘Biogenic amines as hygienic quality indicators of tuna. Relationships with microbial counts, ATPrelated compounds, volatile amines and organoleptic changes’, J Agric Food Chem, 45, 2036–2041. vidal-carou m c, latorre-moratalla m l and bover-cid s (2009), ‘Biogenic amines’, in Nollet L M L and Toldrá F, Handbook of Processed Meats and Poultry Analysis, New York, CRC Press, 665–686. wakabayashi k and sugimura t (1998), Heterocyclic amines formed in the diet: carcinogenicity and its modulation by dietary factors, J Nutr Biochem, 9, 604–612. wang g, lee a s, lewis m, kamath b and archer r k (1999), ‘Accelerated solvent extraction and gas chromatography/mass spectrometry for determination of polycyclic aromatic hydrocarbons in smoked food samples’, J Agric Food Chem, 47, 1062–1066.

© Woodhead Publishing Limited, 2011

Heat and processing generated contaminants in processed meats

507

widmark e p m (1939), ‘Presence of cancer-producing substances in roasted food’, Nature, 143, 984–984. wilms m (2000), ‘The developing of modern smokehouses – ecological and economical aspects’, Fleischwirtsch Int, 80, 4–5. yabiku h y, martins m s and takahashi m y (1993), ‘Levels of benzo(a)pyrene and other polycyclic aromatic hydrocarbons in liquid smoke flavour and some smoked foods’, Food Addit Contam, 10, 399–405. yurchenko s and mölder u (2007), ‘The occurrence of volatile N-nitrosamines in Estonian meat products’, Food Chem, 100, 1713–1721.

© Woodhead Publishing Limited, 2011

20 Improving the sensory quality of cured and fermented meat products F. Toldrá, Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Spain

Abstract: There are a large number of cured and fermented meat products which are characterised by a ripening process accompanied by a more or less intense drying. These processes involve a large number of chemical and biochemical reactions which are closely related to the development of colour, flavour and texture. The (bio)chemical reactions that mainly affect proteins and lipids, and are basic for sensory quality development especially along the ripening period, will be discussed in this chapter. Key words: dry-cured ham, dry-fermented sausage, cured meat, fermented meat, flavour, sensory quality.

20.1 Introduction The origin of cured and fermented meat products is very old. Initially, this technology was used for preservation purposes and this was the primary use for centuries. The technology was largely empirical, following experience transmitted by manufacturers from generation to generation until refrigeration was expanded during the last century. Then, the purpose was progressively accommodated to meet consumer demands for a better product from a sensory point of view. Consequently, processing technologies have evolved, and in cases significantly, in the last decades as a result of the knowledge ascertained on the chemical and biochemical mechanisms related with product flavor and texture development (Parolari, 1996; Toldrá et al., 1997; Toldrá, 1998; Toldrá and Flores, 1998). Many cured and fermented meat products are usually consumed raw with no need for further smoking or cooking. In general, all of these products are characterised by the use of salt and commonly nitrate and/or nitrite. These products may consist of an entire meat piece which is ripened, dried

© Woodhead Publishing Limited, 2011

Improving the sensory quality of cured and fermented meat products

509

and/or smoked (main products are dry-cured ham and dry-cured pork loin) or a mixture of minced meat and fat, which is stuffed into a casing, fermented, dried and/or smoked (main products are dry- and semidry-fermented sausages) (Toldrá, 2002; Demeyer and Toldrá, 2004). The processing technologies may differ depending on the drying intensity, ripening length or smoking. The raw materials also exert an important influence on the final sensory quality. Mediterranean products mainly consist of dry-cured ham and dryfermented sausages. Some of the most well-known hams are Spanish Iberian and Serrano hams, Italian Parma and San Danielle hams and French Bayonne ham. A common characteristic is the long processing time (at least 6 months or even 1–2 years) and the weight loss after drying, around 32–34% (Toldrá, 2004a, 2006a). Chinese Xuanwei, Ching Hua or Yunnan hams are also dried for relatively long periods of time. In the case of hams produced in Northern Europe and the USA they are salted and ripened for shorter periods (few weeks) and then smoked. Some of these products are the Kentucky and Virginia country-style hams, the traditional German Westphalian ham and the Finnish ‘sauna’ hams (Campbell-Platt, 1995). In the case of sausages, Mediterranean sausages undergo fermentation at mild temperatures and then followed by a ripening period for long durations of time in the absence of smoking. Some of these products are French saucisson, Spanish chorizo and salchichón and Italian salami (Toldrá, 2004b). Conversely, Northern–European products are usually processed in a shorter period of time and smoked. Some products are the German and Hungarian-style salamis (Leistner, 1992). When weight loss exceeds 30%, sausages are denominated dry-fermented but if it is less 20% they are known as described as semidry-fermented sausages (Sebranek, 2004). This chapter reviews the current knowledge on the development of sensory quality in all of these product types.

20.2 Biochemical basis for flavour development Flavour development in cured and fermented meat products is a rather complex process involving a large number of enzymatic and chemical reactions. Many factors, such as the type and quality of raw materials, other ingredients and additives used, processing conditions and type of packaging, affect such reactions. Most of the important biochemical changes observed in dry-cured ham and dry fermented sausages are related to the modification of proteins and lipids and these changes are governed by the presence and mode of action of important groups of enzymes. These enzymes may be derived from either muscle origin (as in the case of ham) or muscle and microbial origins (as in the case of fermented sausages). Thus, proteolysis and lipolysis constitute important enzymatic phenomena, followed by oxidation, all of them being

© Woodhead Publishing Limited, 2011

510

Processed meats

responsible for the generation of compounds with direct influence on flavour.

20.2.1 Proteolysis There is an important degradation of meat proteins during processing and which becomes even more pronounced during the processes of curing and fermentation. The main outcome of proteolysis consists in the generation of peptides and free amino acids from the progressive enzymatic degradation of major sarcoplasmic and myofibrillar proteins. This chain of reactions constitutes the basis for the biochemical changes reported in such types of products (Toldrá, 2006b). A flow chart representing the main proteolytic reactions is shown in Fig. 20.1. From this figure it can be readily observed that numerous enzymes are involved in proteolysis. Dry-cured ham The muscle proteases are mainly involved in dry-curing of ham and basically consist of the endoproteases (cathepsins B, D, H and L, calpains I and II), peptidases (tripeptidylpeptidases I and II, dipeptidylpeptidases I, II, III and IV) and aminopeptidases (alanyl, arginyl, leucyl and methyl aminopeptidases) (Toldrá, 2005). The levels of all these proteases in the meat is dependent on several production factors such as the type of crossbreeding (Armero et al., 1999a, 1999b; Soriano et al., 2005) and the age of the animal at slaughter (Toldrá et al., 1996; Rosell and Toldrá, 1998). For most of these enzymes, their activity is high and thus their activity is prolonged during the long dry-curing processes (Toldrá, 2004c). The amount of salt exerts a control action over the activity of these enzymes, especially the endoproteases, and this is one of the main reasons why these products

Muscle proteins Cathepsins & calpains

Polypeptides Peptidases

Peptides Non-volatile taste compounds

Furt

her

reac

tion s

Aminopeptidases

Free amino acids

her

Furt

Volatile aroma compounds

s tion reac

Fig. 20.1 Flow chart showing major steps in postmortem proteolysis. From Toldrá, F., Proteolysis and lipolysis in flavour development of dry-cured meat products. Meat Science 1998, 49, S101–S110 with permission from Elsevier.

© Woodhead Publishing Limited, 2011

Improving the sensory quality of cured and fermented meat products

511

1.00

Water activity

0.95

0.90

0.85

0.80

0.75

Outer (SM) Inner (BF) 0

2

3.5

5

7

10

Time (months) Note: SM = semimembranosous, BF = biceps femoris

Fig. 20.2 Evolution of water activity in the external muscle semimembranosus and the internal muscle biceps femoris along the processing of dry-cured ham. From Toldrá, F., The role of muscle enzymes in dry-cured meat products with different drying conditions, Trends in Food Science and Technology, 2006, 17, 164–168 with permission from Elsevier.

do not reach an excessive softness if correctly salted (Parolari et al., 1994; Toldrá, 2006b). In addition to texture, salt also contributes to the characteristic salty taste of these products (Andrés et al., 2004). These proteases are also affected by decreases in water activity during processing. Water activity is reduced as a consequence of the intense moisture loss experienced during drying. This loss of moisture may be as high as 34% in weight for dry-cured hams. An example of water activity reduction during the processing of drycured ham is shown in Fig. 20.2. An example of the effect that water activity decreases exerts on these enzymes, like endopeptidases, may be observed in Fig. 20.3. The final step in the proteolysis chain is the generation of free amino acids which is significant in dry-cured ham and relatively high in dry fermented sausages (Toldrá et al., 2000). These amino acids contribute directly to a nice cured taste (Toldrá, 2006b) and can also contribute to aroma through further chemical reactions (Flores et al., 1997, 1998). Dry-fermented sausages There are also proteolytic enzymes from microbial origin involved in the processing of dry-fermented sausages. In fact, there is a combined action of muscle and microbial proteases. Owing to the acid pH in the sausages, some authors have concluded after studies with the use of antibiotics to inhibit microbial growth, that cathepsin D is the main muscle endoprotease

© Woodhead Publishing Limited, 2011

512

Processed meats 120

1 0.95 0.9 0.85

Relative activity (%)

100 80 60 40 20 0 Cath B

Cath B+L

Cath H

Cath D

Calp

Note: Cath = cathepsins, Calp = calpain

Fig. 20.3 Effect of different water activity levels on the activity of muscle cathepsins and calpain. From Toldrá, F., The role of muscle enzymes in dry-cured meat products with different drying conditons, Trends in Food Science and Technology, 2006, 17, 164–168 with permission from Elsevier.

involved in proteolysis. Cathepsins B and L are limited in their action against meat proteins (Molly et al., 1997). The main microbial endoproteases are associated with the cell envelope of lactic acid bacteria used as starter cultures. Some lactobacilli and yeasts have demonstrated tremendous capabilities of degrading sarcoplasmic proteins and some myofibrillar proteins (Fadda et al., 1999a, 1999b; Sanz et al., 1999a, 1999b; Santos et al., 2001). These bacteria also contain a good number of peptidases and aminopeptidases: tripeptidase (Sanz et al., 1998), dipeptidase (Montel et al., 1995), an arginine aminopeptidase (Sanz and Toldrá, 2002) and a major aminopeptidase similar to Pep L (Sanz and Toldrá, 1997). Other proteases may originate from yeasts such as Debaryomices hansenii that also contains endoproteases such as proteases A and B (Bolumar et al., 2005, 2008) and prolyl and arginyl aminopeptidases (Bolumar et al., 2003a, 2003b). Muscle and microbial peptidases can also generate peptides from certain proteins like myoglobin, creatin kinase, troponin T and I and myosin light chain 2, that can be further hydrolysed to smaller peptides (Hughes et al., 2002). As in the case of hams, the amount of salt exerts a controlling action over the activity of these proteolytic enzymes, especially the endoproteases, and also contributes to the characteristic salty taste of these products. Proteases are also affected by water activity that is reduced as a consequence of drying and where moisture loss can reach more than 20% for semidry and 30% for dry-fermented sausages. Peptidases and aminopeptidases are

© Woodhead Publishing Limited, 2011

Improving the sensory quality of cured and fermented meat products

513

usually active at neutral pH values and, thus, can be affected by acid pH as found in fermented sausages. The final step in the proteolysis chain is the generation of free amino acids which is relatively high in dry fermented sausages (Toldrá et al., 2000). These amino acids can contribute to characteristic tastes like beefy, sweet, bitter and astringent (Henriksen and Stahnke, 1997; Talon, 2004) and can also contribute to aroma through further reactions that may be chemical or caused by microbial enzymes capable of transforming amino acids: (1) degradation reactions through Strecker reactions (Flores et al., 1998), (2) decarboxylation by microbial decarboxylases to produce amines (Ordoñez et al., 1999), (3) oxidative deamination of some amino acids producing ammonia (Ordoñez et al., 1999) and (4) transamination which is the conversion into other amino acids catalysed by amino transferases (Durá et al., 2002). For instance, branched-chain aldehydes may be produced after microbial metabolism (i.e. by Staphylococcus, Kocuria or Debaryomices hansenii) of leucine, valine and isoleucine (Demeyer et al., 2000).

20.2.2 Lipolysis Triacylglycerols and phospholipids are enzymatically hydrolysed to generate free fatty acids. The primary muscle lipolytic enzymes involved in such lipolysis in dry-cured ham are lysosomal acid lipase and acid phospholipase (Motilva et al., 1993a) while a neutral lipase is responsible for lipolysis in adipose tissue (Motilva et al., 1993b). These enzymes show an intense action during the first 10 months of ham processing (Motilva et al., 1993a, 1993b; Vestergaard et al., 2000). Oleic, linoleic, estearic and palmitic acids are usually generated at a faster rate from phospholipid degradation (Toldrá, 2002). In the case of sausages, there is a combined action on fat hydrolysis of muscle lipolytic enzymes and microbial lipases (Hierro et al., 1997; Molly et al., 1997). The composition and content in volatile compounds depend on the processing; consequently, compounds such as terpenes may appear if spices have been added to the original formulation. The intensity of proteolysis has also a marked influence on the profile of volatile compounds: for instance, the presence of furans, sulphur compounds and pyrazines may indicate a high proteolysis in mild pH sausages (Toldrá and Flores, 2007). The generated free fatty acids with double bonds are prone to further oxidative reactions as will be discussed in the following section. Figure 20.4 shows a flow chart of the major steps in lipolysis and oxidation.

20.2.3 Glycolysis in fermented meat The fermentation of carbohydrates by lactic acid bacteria through the glycolytic or Embden–Meyerhof pathway generates lactic acid as the final product. The pH drops towards acid values approaching the isoelectric point of myofibrillar proteins that tend to coagulate and some water is

© Woodhead Publishing Limited, 2011

514

Processed meats Lipids

Triglycerides Lipases

Phospholipids Phospholipases Free fatty acids Oxidation Radiations, heat, ions,... oxidative enzymes,...

Hydroperoxides Further reactions interactions with peptides, amino acids,... secondary oxidation products,...

Volatile aroma compounds

Fig. 20.4 Flow chart showing major steps in postmortem lipolysis and oxidation to flavour compounds. From Toldrá, F., Proteolysis and lipolysis in flavour development of dry-cured meat products. Meat Science 1998, 49, S101–S110 with permission from Elsevier.

released (Toldrá, 2007). The generation rate of lactic acid is important in order to correctly estimate pH drop, but this depends on a large number of variables like the type of microorganisms present, fermentation temperature and duration, type and amount of added carbohydrates and further processing conditions (amount of salt, nitrite, other microorganisms added, etc.). Homofermentative pathways are prefered since heterofermentative fermentations also produce other by-products like: acetate, formate, ethanol and acetoin, all of which can affect the sensory quality of the sausage (Demeyer and Stahnke, 2002). The generated lactic acid may be either the d(−) or l(+) configuration and its ratio depends on the action of l and d lactate dehydrogenase, respectively, and the presence of lactate racemase (Demeyer and Toldrá, 2004).

20.2.4 Oxidation Pork meat is the usual raw material used for sausage production. The fat in pork meat is characterised by near 50% mono- and about 15–20% of polyunsaturated fatty acids. These acids, containing double bonds, are susceptible to further oxidative reactions that can generate volatile compounds with desirable aromas or others possessing unpleasant aromas (Skibsted et al., 1998). These oxidative processes can be initiated either by muscle oxidative enzymes, such as lipoxygenases and cyclooxygenases, or by external catalysers such as the presence of light, heating conditions during drying

© Woodhead Publishing Limited, 2011

Improving the sensory quality of cured and fermented meat products

515

or the presence of moisture and/or metallic cations (Toldrá et al., 2001). Oxidation is propagated by peroxide radicals forming hydroxyperoxides (primary oxidation products). These compounds are very reactive and generate secondary oxidation products that contribute to flavour. Numerous volatile compounds are generated through these reactions with various levels of contribution to the final aroma of the product. So, aliphatic hydrocarbons generally contribute poorly to flavour, alcohols show a high odour threshold while aldehydes show low odour threshold (Stahnke, 2002). Some esters may also be generated, which is typical of products without nitrate or nitrite addition, like Parma hams (Toldrá, 2006b).

20.3 Basis for colour and texture development in cured meats The typical cured red-pink colour is mainly due to the reaction of nitrite with myoglobin (Pegg and Shahidi, 2000). The nitrite, initially added to the product, is reduced to nitric oxide which then reacts with myoglobin, thereby forming the red-colured nitric oxide myoglobin (Demeyer and Toldrá, 2004). In the case where nitrate is added to the product, it must be previously reduced to nitrite through the action of the microbial enzyme nitrate reductase. The amount of colour development is proportional to the available myoglobin in the meat; which is largely dependent on the type of muscle used for processing and age of the animal from which it came. The content of myoglobin is larger in oxidative muscles derived from older animals (Laborde et al., 1985; Aristoy and Toldrá, 1998). Optimal colour formation in sausages depends on the fermentation process and the reduction in pH and oxygen depletion, because a more acid pH facilitates better nitrite reaction (Moller and Skibsted, 2007). Meat colour should be homogeneous through an entire cut product slice but some heterogeneity may be observed when the drying process is not correct (Pérez-Alvarez et al., 1999). Other descriptors, closely related to the appearance, are the visual cut, the fat content and the size of the fat particles present, and additionally, on the presence of an optional external mould cover. The texture of these products is closely related to the intensity of drying so those products with more intense drying and associated loss of moisture are of harder texture. This is typical in products possessing small diameters or where longer processing times are employed, but may also be found in products where the relative humidity has been maintained at a lower level than recommended. A fast drying regime may also cause an intense drying in the outer sections of the product, while keeping a higher moisture content in the inner product portions. This is commonly known as case hardening. In addition, the acidification during the fermentation stage in sausages produces lactic acid accumulation and a pH drop towards the isoelectric point of meat proteins. Once these proteins coagulate, their water retention

© Woodhead Publishing Limited, 2011

516

Processed meats

capacity is reduced and the firmness is substantially increased (Talon et al., 2002). In any case, there is a balance for firmness between the forces contributing to hardening and forces contributing to protein breakdown by proteases (Barbut, 2007).

20.4 Processing factors affecting sensory quality of cured meats The control of raw materials is extremely important for the processing of such types of meat products. The fat and protein content of meat may vary, but so also may the enzyme content due to animal genetics and age (Armero et al., 1999a, 1999b, 1999c). The fat quality is also strongly affected by the type of feeding and this will also affect the aroma quality of the final products (Jiménez-Colmenero et al., 2006). In the case of fermented sausages, the choice of the starter cultures is also very important. Typical microbial groups present in a culture consist of a lactic acid bacteria (Lactobacillus sakei, L. curvatus, L. carnosus, L. plantarum, Pedicococcus pentosaceus) that generate lactic acid (pH drop) and a Micrococcaceae (Kocuria varians, Staphylococcus xylosus) or yeast (Debaryomices hansenii) to provide nitrate reduction and lipases for flavor development (Leistner, 1992; Demeyer and Stahnke, 2002). The moulds Penicillium nalgiovense and P. chrysogenum can also be used for external appearance (Toldrá, 2004c, 2006b). Flavour formation may change depending on growth parameters and ripening time, but also according to the composition of the starter cultures (Tjener and Stahnke, 2007). The sensory quality of cured and fermented meat products is highly influenced by processing conditions. For instance, pH affects the enzyme activity during processing so that acid pH values will favour the action of those enzymes with optimal pH towards acid conditions (i.e. cathepsins, lysosomal acid lipase) while neutral pH will favour those with optimal neutral pH (i.e. calpains, peptidases and aminopeptidases). Intracellular bacterial enzymes are protected towards pH if the cell remains intact. When raw material has a high pH value, the resulting dry-cured hams tend to be softer, pastier, more crumbly and adhesive than normal ones (Guerrero et al., 1999). Something similar can be said about temperature. It is evident that higher temperatures will favour enzyme action and microbial development, but this is not always advisable from the point of view of quality since some rancid aromas may develop. Furthermore, excessive temperatures, if accompanied by low relative humidity in the curing chamber, may contribute to important problems during drying, like an excessive hardening due to an excessive loss of moisture. So, the external muscle semimembranosus tends to be harder, darker and dryer than the internal muscle biceps femoris that tends to remain softer, light pinky coloured and more humid (Cava et al., 2000; Toldrá and Flores, 2007).

© Woodhead Publishing Limited, 2011

Improving the sensory quality of cured and fermented meat products

517

The effect of salt content is also very important since sodium chloride exerts a powerful inhibitory action against many muscle and microbial enzymes. For instance, cathepsins are inhibited by salt (Toldrá et al., 1992) and this effect is important in long manufacturing processes, like that used for dry-cured ham manufacture, to control the excess of proteolysis. Consequently, those hams whose salt content has been reduced without any other caution, have softer textures, sometimes gummy-like which is undesirable and rejected by consumers (Andrés et al., 2004). The length of the process contributes to the quality attributes, especially in flavour development, since this gives longer times for enzymatic action, as well as chemical reactions for the generation of aroma compounds. For instance, the generation of free amino acids such as glutamic acid, aspartic acid, methionine, isoleucine, leucine and lysine is well correlated with process duration (Toldrá et al., 2000). The length of the process has been shown to be highly relevant for the development of the cured aroma in long-term manufactured products such as Serrano and Parma hams (Flores et al., 1997).

20.5 Trends to accelerate the processes and/or improve the sensory quality of cured meat products 20.5.1 Dry-cured ham There are numerous approaches being adopted currently in an attempt to accelerate the processing of cured meat products and consequently, improving the sensory quality of such products, especially flavour. A number of strategies have been developed for the processing of dry-cured ham that constitute a very long process. Typical processes take between 6 and 12 months, but in some cases, processing may last up to 2 or 3 years depending on the intended final quality of the product. Several strategies have been reported during the last decades trying to accelerate the process (Table 20.1). The main goal was to improve the salt penetration into the ham and facilitate salt diffusion through the entire piece of meat. Other attemps have focused on the brine salting of hams while still frozen. The process consists of allowing hams to thaw while vacuum impregnation is applied (Barat et al., 2006). Using this process, total processing time was reduced marginally and hams possessed similar biochemical processes and yielded a similar final quality product, especially from a sensory perspective (Flores et al., 2006). Another important trend is salt reduction, as is being increasingly demanded by consumers and health authorities alike. Taking into account that total salt content in hams may reach 5% or even higher, it is necessary to reduce levels. Recent research has been focused on the partial replacement of sodium chloride by other salts such as potassium chloride, calcium chloride and/or magnesium chloride (Blesa et al., 2008). The proportion of

© Woodhead Publishing Limited, 2011

518

Processed meats

Table 20.1 Examples of technologies for accelerated processing of cured and fermented meat products Meat product

Technology applied Main purpose

References

Dry-cured ham

Boning and Improve salt skinning of hams penetration and diffusion

Montgomery et al. (1976), Kemp et al. (1980), Marriott et al. (1983) Leak et al. (1984)

Mechanical tenderisation Freezing and thawing Vacuum impregnation Replacement by other salts Dry-fermented Addition of serine sausages proteinase from lactobacillus Addition of alcalase from B. licheniformis Addition of proteinase from L. paracasei suesp paracasei Addition of neutral proteinase from B. subtilis Addition of neutrase from B. subtilis var. amiloliquefaciens Addition of fungal protease from A. oryzae Addition of pronase E from S. griseus Cell-free extracts Cell extracts Replacement by other salts

Improve salt penetration and diffusion Improve salt penetration and diffusion Improve salt penetration and diffusion Sodium reduction

Kemp et al. (1982), Motilva et al. (1994), Flores et al. (2009) Barat et al. (2006) Blesa et al. (2008)

Enhanced proteolysis Naes et al. (1995) and flavour development Enhanced proteolysis Hagen et al. (1996) and flavour development Enhanced proteolysis Hagen et al. (1996) and flavour development Enhanced proteolysis Zapelena et al. and flavour (1998) development Enhanced proteolysis Zapelena et al. and flavour (1997) development Enhanced proteolysis and flavour development Enhanced proteolysis and flavour development Enhanced proteolysis and flavour development Enhanced proteolysis and flavour development Sodium reduction

© Woodhead Publishing Limited, 2011

Ordoñez et al. (1999) Díaz et al. (1993) Fadda et al. (1999a, 1999b) Durá et al. (2004a, 2004b, 2004c) Gelabert et al. (2003), Gimeno et al. (2001)

Improving the sensory quality of cured and fermented meat products

519

these salts must be carefully defined because an excess may result in sensory defects (i.e. bitterness by an excess of potassium or metallic after taste by an excess of magnesium) (Toldrá and Barat, 2009). Another important point is the different diffusion rates for such cations into the ham that must be taken into account in order to have a homogeneous product and also the different inhibitory effects that such salts have on the different muscle proteases (Armenteros et al., 2009). Finally, nitrate and nitrite reduction and/or complete elimination is another target that is already accomplished for some hams (i.e. Parma hams) and is now a major focus for hams produced in other regions of the globe. Of course, this reduction, or even complete elimination, must be accompanied by exhaustive controls and hygienic measures as well as a rearrangement of the process in order to produce a similar colour in the final product.

20.5.2 Dry-fermented sausages An important trend for several years has consisted of the accelerated processing through the addition of enzymes, mainly proteinases (Table 20.1). The final goal was to improve the sensory quality, mainly flavour development and overall acceptability through the action of certain proteolytic enzymes. The addition of these enzymes is rather challenging because they are quite difficult to control. Furthermore, the specific amount added to the sausage is very important since an excess may give intense proteolysis and thus, texture defects, mainly manifesting itself as a softening effect. Finally, it must be taken into account that the generated amino acids also need some additional time for further chemical reactions to generate volatile compounds with desirable aroma properties. In some cases, like papain and bromelain, the result may be negative due to undesirable flavour and texture (Ansorena et al., 2002). Another interesting option is offered through the addition of whole cells or cell-free extracts from either a specific bacteria (Fadda et al., 1999a, 1999b) or a yeast, in an attempt to accelerate and improve the sensory quality of the sausages (Durá et al., 2004a, 2004b, 2004c).

20.6 Sources of further information and advice 20.6.1

Books

Toldrá, F. 2002. Dry-cured Meat Products. Wiley-Blackwell Pub. Co., Ames, IA, USA. Toldrá, F., Ed. 2002. Research Advances in the Quality of Meat and Meat Products. Research Signpost, Trivandrum, India. Toldrá, F. Ed. 2007. Handbook of Fermented Meat and Poultry. WileyBlackwell Pub. Co., Ames, IA, USA.

© Woodhead Publishing Limited, 2011

520 20.6.2

Processed meats Chapters of books

Flores, M., Sanz, Y., Spanier, A.M., Aristoy, M.C. & Toldrá, F. 1998. Contribution of muscle and microbial aminopeptidases to flavor development in dry-cured meat products. In: Developments in Food Science. Food Flavor: Generation, Analysis and Process Influence (E.T. Contis, C.T. Ho, C.J. Mussinan, T.H. Parliament, F. Shahidi & A.M. Spanier, Eds.), Elsevier Science BV, Amsterdam, The Netherlands, pp. 547–557. Toldrá, F., Flores, M., Aristoy, M-C., Navarro, J-L. & Flores, J. 1997. New developments in dry-cured ham. In: Chemistry of Novel Foods (A.M. Spanier, M. Tamura, H. Okai, & O. Mills, Eds.), Allured Pub. Co. Inc. Carol Stream, IL, pp. 259–272. Toldrá, F. 2004. Dry-cured ham. In: Handbook of Food and Beverage Fermentation Technology (Y.H. Hui, L.M. Goddik, J. Josephsen, P.S. Stanfield, A.S. Hansen, W.K. Nip & F. Toldrá, Eds.), Marcel Dekker Inc., New York, pp. 369–384. Toldrá, F. 2004. Curing: dry. In: Encyclopedia of Meat Sciences (W. Jensen, C. Devine & M. Dikemann, Eds.), Elsevier Science Ltd, London, UK, pp. 360–365. Toldrá, F. 2004. Ethnic meat products: Mediterranean. In: Encyclopedia of Meat Sciences (W. Jensen, C. Devine & M. Dikemann, Eds.), Elsevier Science Ltd., London, pp. 451–453. Toldrá, F. 2006. Biochemical proteolysis basis for improved processing of dry-cured meats. In: Advanced Technologies for Meat Processing (L.M.L. Nollet & F. Toldrá, Eds.) CRC Press, Boca Raton, FL, 329– 351. Toldrá, F. 2007. Dry-cured ham. In: Handbook of Food Science, Technology and Engineering (Y.H. Hui, E. Castell-Perez, L.M. Cunha, I. GuerreroLegarreta, H.H. Liang, Y.M. Lo, D.L. Marshall, W.K. Nip, F. Shahidi, F. Sherkat, R.J. Winger, K.L. Yam, Eds.), vol. 4, CRC Press, Boca Raton, FL, pp. 164-1–164-11. Toldrá, F. 2007. Ham. In: Handbook of Food Product Manufacturing (Y.H. Hui, R. Chandan, S. Clark, N. Cross, J. Dobbs, W.J. Hurst, L.M.L. Nollet, E. Shimoni, N. Sinha, E.B. Smith, S. Surapat, A. Titchenal & F. Toldrá, Eds.), Vol. 2, John Wiley Interscience, New York, pp. 231–247.

20.7 References and further reading andrés, a.i., cava, r., ventanas, j., thovar, v. & ruiz, j. 2004. Sensory characteristics of Iberian ham: Influence of salt content and processing conditions. Meat Science 68, 45–51. ansorena, d., astiasarán, i. & bello, j. 2002. Use of exogenous enzymes in dry fermented sausages. In: Research Advances in the Quality of Meat and Meat Products (F. Toldrá Ed.) Research Signpost, Trivandrum, India, pp. 157–174.

© Woodhead Publishing Limited, 2011

Improving the sensory quality of cured and fermented meat products

521

aristoy, m.c. & toldrá, f. 1998. Concentration of free amino acids and dipeptides in porcine skeletal muscles with different oxidative patterns. Meat Science, 50, 327–332. armenteros, m., aristoy, m.c. & toldrá, f. 2009. Effect of sodium, potassium, calcium and magnesium chloride salts on pork muscle proteases. European Food Research and Technology, 229, 93–98. armero, e., barbosa, j.a., toldrá, f., baselga, m. & pla, m. 1999a. Effects of the terminal sire type and sex on pork muscle cathepsins (B, B+L and H), cysteine proteinase inhibitors and lipolytic enzyme activities. Meat Science, 51, 185–189. armero, e., baselga, m., aristoy, m-c. & toldrá, f. 1999b. Effects of sire types and sex on pork muscle exopeptidase activity and the content of natural dipeptides and free amino acids. Journal of the Science of Food and Agriculture, 79, 1280–1284. armero, e., flores, m., toldrá, f., barbosa, j-a., olivet, j., pla, m. & baselga, m. 1999c. Effects of pig sire types and sex on carcass traits, meat quality and sensory quality of dry-cured ham. Journal of the Science of Food and Agriculture, 79, 1147–1154. barat, j.m., grau, r., ibáñez, j.b., pagán, m.j., flores, m., toldrá, f. & fito, p. 2006. Accelerated processing of dry-cured ham. Part I. Viability of the use of brine thawing/salting operation. Meat Science 72, 757–765. barbut, s. 2007. Texture. In: Handbook of Fermented Meat and Poultry (F. Toldrá, Y.H. Hui, I. Astiasarán, W.K. Nip, J.G. Sebranek, E.T.F. Silveira, L.H. Stahnke & R. Talon, Eds.), Blackwell Publishing, Ames, IA, pp. 217–226. blesa, e., aliño, m., barat, j.m., grau, r., toldrá, f. & pagán, m.j. 2008. Microbiology of dry-cured ham during the post-salting stage as affected by partial replacement of NaCl by other salts. Meat Science, 78, 135–142. bolumar, t., sanz, y., aristoy, m.c. & toldrá, f. 2003a. Purification and properties of an arginyl aminopeptidase from Debaryomyces hansenii. International Journal of Food Microbiology, 86, 141–151. bolumar, t., sanz, y., aristoy, m.c. & toldrá, f. 2003b. Purification and characterization of a prolyl aminopeptidase from Debaryomyces hansenii. Applied and Environmental Microbiology, 69, 227–232. bolumar, t., sanz, y., aristoy, m.c. & toldrá, f. 2005. Protease B from Debaryomyces hansenii. Purification and biochemical properties. International Journal of Food Microbiology, 98, 167–177. bolumar, t., sanz, y., aristoy, m.-c. & toldrá, f. 2008. Purification and characterisation of proteases A and D from Debaryomices hansenii. International Journal of Food Microbiology, 124, 135–141. campbell-platt, g. 1995. Fermented meats – a world perspective. In: Fermented Meats (G. Campbell-Platt, P.E. Cook, Eds.), Blackie Academic & Professional, London, pp. 39–52. cava, r., ventanas, j., ruiz, j., andrés, a.i. & antequera, t. 2000. Sensory characteristics of Iberian ham: Influence of rearing system and muscle location. Food Science and Technology International, 6, 235–242. demeyer, d. & stahnke, l. 2002. Quality control of fermented meat products. In: Meat processing: Improving quality (J. Kerry, J. Kerry & D. Ledward, Eds.) Cambridge, Woodhead Publishing, 359–393. demeyer, d.i. & toldrá, f. 2004. Fermentation. In: Encyclopedia of Meat Sciences (W. Jensen, C. Devine & M. Dikemann, Eds.), Elsevier Science Ltd, London, pp. 467–474. demeyer, d.i., raemakers, m., rizzo, a., holck, a., de smedt, a., ten brink, b., hagen, b., montel, c., zanardi, e., murbrek, e., leroy, f., vanderdriessche, f., lorentsen, k., venema, k., sunesen, l., stahnke, l., de vuyst, l., talon, r., chizzolini, r. &

© Woodhead Publishing Limited, 2011

522

Processed meats

eerola, s. 2000. Control of bioflavor and safety in fermented sausages: first results of a European project. Food Research International, 33, 171–180. díaz, o., fernández, m., garcía de fernando, g.d., de la hoz, l. & ordoñez, j.a. 1993. Effect of the addition of pronase E on the proteolysis in dry-fermented sausages. Meat Science, 34, 205–211. durá, m.a., flores, m. & toldrá, f. 2002. Purification and characterisation of a glutaminase from Debaryomices spp. International Journal of Food Microbiology, 76, 117–126. durá, m.a., flores, m. & toldrá, f. 2004a. Effect of Debaryomyces spp on the proteolysis of dry-fermented sausages. Meat Science, 68, 319–328. durá, m.a., flores, m. & toldrá, f. 2004b. Effect of Debaryomyces spp on aroma formation and sensory quality of dry-fermented sausages. Meat Science, 68, 439–446. durá, m.a., flores, m. & toldrá, f. 2004c. Effect of growth phase and dry-cured sausage processing conditions on Debaryomyces spp. generation of volatile compounds from branched-chain amino acids. Food Chemistry, 86, 391–399. fadda, s., sanz, y., vignolo, g., aristoy, m-c., oliver, g. & toldrá, f. 1999a. Hydrolysis of pork muscle sarcoplasmic proteins by Lactobacillus curvatus and Lactobacillus sake. Applied and Environmental Microbiology, 65, 578–584. fadda, s., sanz, y., vignolo, g., aristoy, m-c., oliver, g. & toldrá, f. 1999b. Characterization of muscle sarcoplasmic and myofibrillar protein hydrolysis caused by Lactobacillus plantarum. Applied and Environmental Microbiology, 65, 3540–3546. flores, j. & toldrá, f. 1993. Curing: Processes and applications. In: Encyclopedia of Food Science, Food Technology and Nutrition (R. Macrae, R. Robinson, M. Sadle, G. Fullerlove, Eds.), Academic Press, London, pp. 1277–1282. flores, m., grimm, c.c., toldrá, f. & spanier, a.m. 1997. Correlations of sensory and volatile compounds of Spanish Serrano dry-cured ham as a function of two processing times. Journal of Agricultural & Food Chemistry, 45, 2178– 2186. flores, m., spanier, a.m. & toldrá, f. 1998. Flavour analysis of dry-cured ham. In: Flavor of Meat, Meat Products and Seafoods (F. Shahidi, Ed.), Blackie Academic & Professional, London, pp. 320–341. flores, m., barat, j.m., aristoy, m.c., peris, m.m., grau, r. & toldrá, f. 2006. Accelerated processing of dry-cured ham. Part 2. Influence of brine thawing/salting operation on proteolysis and sensory acceptability. Meat Science, 72, 766–772. flores, m., aristoy, m.c., antequera, t. barat, j.m. & toldrá, f. 2009. Effect of prefreezing hams on endogenous enzyme activity during the procesing of Iberian dry-cured hams. Meat Science, 82, 241–246. gelabert, j., gou, p., guerrero, l. & arnau, j. 2003. Effect of sodium chloride replacement on some characteristics of fermented sausages. Meat Science, 65, 833–839. gimeno, o., astiasarán, i. & bello, j. 2001. Calcium ascorbate as a potential partial substitute for NaCl in dry fermented sausages: effect on colour, texture and hygiene quality at different concentrations. Journal of Agricultural and Food Chemistry, 46, 4372–4375. guerrero, l., gou, p. & arnau, j. 1999. The influence of meat pH on mechanical and sensory textural properties of dry-cured ham. Meat Sci. 52, 267–273. hagen, b.f., berdagué, j.l., holck, a.j., naes, h. & blom, h. 1996. Bacterial proteinase reduces maturation time of dry fermented sausages. Journal of Food Science, 61, 1024–1029. henriksen, a.p. & stahnke, l.h. 1997. Sensory and chromatographic evaluations of water soluble fraction from dried sausages. Journal of Agricultural and Food Chemistry, 45, 2679–2684.

© Woodhead Publishing Limited, 2011

Improving the sensory quality of cured and fermented meat products

523

hierro, e., de la hoz, l. & ordoñez, j.a. 1997. Contribution of microbial and meat endogenous enzymes to the lipolysis of dry fermented sausages. Journal of Agricultural and Food Chemistry, 45, 2989–2995. hughes, m.c., kerry, j.p., arendt, e.k., kenneally, p.m., mcsweeney, p.l.h. & o’neill, e.e. 2002. Characterization of proteolysis during the ripening of semidry fermented sausages. Meat Science 62, 205–216. jiménez colmenero, f., reig, m. & toldrá, f. 2006. New approaches for the development of functional meat products. In: Advanced Technologies for Meat Processing (L.M.L. Nollet & F. Toldrá, Eds.), CRC Press, Boca Raton, FL, USA, 275–308. kemp, j.d., abidoye, d.f.o., langlois, b.e., franklin, j.b. & fox, j.d. 1980. Effect of curing ingredients, skinning, and boning on yield, quality, and microflora of country hams. Journal of Food Science, 45, 174–177. kemp, j.d., langlois, b.e. & johnson, a.e. 1982. Effect of pre-cure freezing and thawing on the microflora, fat characteristics and palatability of dry-cured ham. Journal of Food Protection, 45, 244–248. laborde, d., talmant, a. & monin, g. 1985. Activités enzymatiques métaboliques et contractiles de 30 muscles du porc. Relations avec le pH ultime atteint après la mort. Reproduction and Nutrition Development, 25, 619–628. leak, f.w., kemp, j.d., langlois, b.e. & fox, j.d. 1984. Effect of tumbling and tumbling time on quality and microflora of dry-cured hams. Journal of Food Science, 49, 695–698. leistner, l. 1992. The essentials of producing stable and safe raw fermented sausages. In: New Technologies for Meat and Meat Products (F.J.M. Smulders, F. Toldrá, J. Flores & M. Prieto, Eds.), Audet, Nijmegen, The Netherlands, pp. 1–19. marriott n.g., tracy j.b., kelly r.f. & graham p.p. 1983. Accelerated processing of boneless hams to dry cured state. Journal of Food Protection, 46, 717–721. marriott, n.g., graham, p.p., shaer, c.k. & phelps, s.k. 1987. Accelerated production of dry cured hams. Meat Science, 19, 53–64. marriott, n.g., graham, p.p. & claus, j.r. 1992. Accelerated dry curing of pork legs (hams): a review. Journal of Muscle Foods, 3, 159–168. moller, j.k.s. & skibsted, l.h. 2007. Color. In: Handbook of Fermented Meat and Poultry (F. Toldrá, Y.H. Hui, I. Astiasarán, W.K. Nip, J.G. Sebranek, E.T.F. Silveira, L.H. Stahnke & R. Talon Eds.), Blackwell Publishing, Ames, Iowa, pp. 203–216. molly, k., demeyer, d.i., johansson, g., raemaekers, m., ghistelinck, m. & geenen, i. 1997. The importance of meat enzymes in ripening and flavor generation in dry fermented sausages. First results of a European project. Food Chemistry 54, 539–545. montel, m.c., seronine, m.p., talon, r. & hebraud, m. 1995. Purification and characterization of a dipeptidase from Lactobacillus sake. Applied Environmental Microbiology, 61, 837–839. montgomery, r.e., kemp, j.d. & fox, j.d. 1976. Shrinkage, palatability, and chemical characteristics of dry-cured country ham as affected by skinning procedure. Journal of Food Science, 41, 1110–1115. motilva, m.j., toldrá, f., nieto, p. & flores, j. 1993a. Muscle lipolysis phenomena in the processing of dry-cured ham. Food Chemistry 48, 121–125. motilva, m.j., toldrá, f., aristoy, m.c. & flores, j. 1993b. Subcutaneous adipose tissue lipolysis in the processing of dry-cured ham. Journal of Food Biochemistry 16, 323–335. motilva, m.j., toldrá, f., nadal, m.i. & flores, j. 1994. Pre-freezing hams affects hydrolysis during dry curing. Journal of Food Science, 59, 303–305. naes, h., holck, a.l., axelsson, h., andersen, h.j. & blom, h. 1995. Accelerated ripening of dry-fermented sausage by addition of a Lactobacillus proteinase. International Journal of Food Science & Technology, 29, 651–659.

© Woodhead Publishing Limited, 2011

524

Processed meats

ordoñez, j.a., hierro, e.m., bruna, j.m. & de la hoz, l. 1999. Changes in the components of dry-fermented sausages during ripening. Critical Reviews in Food Science & Nutrition, 39, 329–367. parolari, g. 1996. Review: Achievements, needs and perspectives in dry-cured ham technology: the example of Parma ham. Food Science & Technology International, 2, 69–78. parolari, g., virgili, r. & schivazzappa, c. 1994. Relationship between cathepsin B activity and compositional parameters in dry-cured hams of normal and defective texture. Meat Sci 38, 117–122. pegg, r.b. & shahidi, f. 2000. Nitrite Curing of Meat, Food & Nutrition Press, Trumbull, CT, pp. 23–66. pérez-alvarez, j.a., sayas-barberá, m.e. & fernández-lópez, j. 1999. Chemical and color characteristics of Spanish dry-cured ham at the end of the aging process. J Muscle Foods 10(2), 195–201. rosell, c.m. & toldrá, f. 1998. Comparison of muscle proteolytic and lipolytic enzyme levels in raw hams from Iberian and White pigs. Journal of the Science of Food and Agriculture, 76, 117–122. santos, n.n., santos, r.c., sanz, y., bolumar, t., aristoy, m-c. & toldrá, f. 2001. Hydrolysis of muscle sarcoplasmic proteins by Debaryomyces hansenii. International Journal of Food Microbiology, 68, 199–206. sanz, y. & toldrá, f. 1997. Purification and characterization of an aminopeptidase from Lactobacillus sake. Journal of Agricultural and Food Chemistry, 45, 1552–1558. sanz, y. & toldrá, f. 2002. Purification and characterization of an arginine aminopeptidase from Lactobacillus sakei. Applied and Environmental Microbiology, 68, 1980–1987. sanz, y., mulholland, f. & toldrá, f. 1998. Purification and characterization of a tripeptidase from Lactobacillus sake. Journal of Agricultural and Food Chemistry, 46, 349–353. sanz, y., fadda, s., vignolo, g., aristoy, m-c., oliver, g. & toldrá, f. 1999a. Hydrolytic action of Lactobacillus casei CRL 705 on pork muscle sarcoplasmic and myofibrillar proteins. Journal of Agricultural and Food Chemistry, 47, 3441–3448. sanz, y., fadda, s., vignolo, g., aristoy, m-c., oliver, g. & toldrá, f. 1999b. Hydrolysis of muscle myofibrillar proteins by Lactobacillus curvatus and Lactobacillus sake. International Journal of Food Microbiology, 53, 115–125. sebranek, j.g. 2004. Semidry fermented sausages. In: Handbook of Food and Beverage Fermentation Technology. (Y.H. Hui, L.M. Goddik, J. Josephsen, P.S. Stanfield, A.S. Hansen, W.K. Nip & F. Toldrá, Eds.), Marcel Dekker, New York, pp. 385–396. skibsted, l.h., mikkelsen, a. & bertelsen g. 1998. Lipid-derived off-flavours in meat. In: Flavor of Meat, Meat Products and Seafoods (F. Shahidi, Ed.), Blackie Academic & Professional, London, pp. 216–256. soriano, a., quiles, r., mariscal, c. & garcía, a. 2005. Pig sire type and sex effects on carcass traits, meta quality and physicochemical and sensory characteristics of Serrano dry-cured ham. Journal Science Food Agriculture 85, 1914–1924. stahnke, l. 2002. Flavour formation in fermented sausage. In: Research Advances in the Quality of Meat and Meat Products (F. Toldrá, Ed.), Research Signpost, Trivandrum, India, pp. 193–223. talon, r. 2004. Dry fermented sausages. In: Handbook of Food and Beverage Fermentation Technology (Y.H. Hui, L.M. Goddik, J. Josephsen, P.S. Stanfield, A.S. Hansen, W.K. Nip & F. Toldrá, Eds.), Marcel-Dekker, New York, pp. 397–416. talon, r., leroy-sétrin, s. & fadda, s. 2002. Bacterial starters involved in the quality of fermented meat products. In: Research Advances in the Quality of Meat

© Woodhead Publishing Limited, 2011

Improving the sensory quality of cured and fermented meat products

525

and Meat Products (F Toldrá, Ed.) Trivandrum (India): Research Signpost, 175–191. tjener, k. & stahnke, l.h. 2007. Flavor. In: Handbook of Fermented Meat and Poultry (F. Toldrá, Y.H. Hui, I. Astiasarán, W.K. Nip, J.G. Sebranek, E.T.F. Silveira, L.H. Stahnke & R. Talon Eds.), Blackwell Publishing, Ames, Iowa, pp. 227–239. toldrá, f. 1992. The enzymology of dry-curing of meat products. In: New Technologies for Meat and Meat Products. (J.M. Smulders, F. Toldrá, J. Flores, M. Prieto Eds.) Audet, Nijmegen, The Netherlands, pp. 209–231. toldrá, f. 1998. Proteolysis and lipolysis in flavour development of dry-cured meat products. Meat Science 49, S101–S110. toldrá, f. 2002. Dry-cured meat products. Wiley-Blackwell, Ames, IA, pp. 7–134. toldrá, f. 2004a. Dry-cured ham. In: Handbook of Food and Beverage Fermentation Technology (Y.H. Hui, L.M. Goddik, J. Josephsen, P.S. Stanfield, A.S. Hansen, W.K. Nip & F. Toldrá, Eds.), Marcel Dekker, New York, pp. 369–384. toldrá, f. 2004b. Ethnic meat products: Mediterranean. In: Encyclopedia of Meat Sciences (W. Jensen, C. Devine & M. Dikemann, Eds.), Elsevier Science Ltd, London, pp. 451–453. toldrá, f. 2004c. Curing: dry. In: Encyclopedia of Meat Sciences (W. Jensen, C. Devine & M. Dikemann, Eds) Elsevier Science Ltd, London, pp. 360–365. toldrá, f. 2005. Dry-cured ham. In: Handbook of Food Science, Technology and Engineering (Y.H. Hui, Ed.), vol. 4, CRC Press, Boca Raton, FL, pp. 164-1–164-11. toldrá, f. 2006a. The role of muscle enzymes in dry-cured meat products with different drying conditions. Trends in Food Science and Technology, 17, 164–168. toldrá, f. 2006b. Biochemistry of processing meat and poultry. In: Food Biochemistry & Food Processing (Y.H. Hui, W.K. Nip, L.M.L. Nollet, G. Paliyath & B.K. Simpson, Eds.), Blackwell Publishing, Ames, IA, pp. 315–335. toldrá f. 2006c. Biochemical proteolysis basis for improved processing of dry-cured meats. In: Advanced Technologies for Meat Processing (L.M.L. Nollet & F. Toldrá, Eds.) CRC Press, Boca Raton, FL, pp. 329–351. toldrá, f. 2007. Fermented meat production. In: Handbook of Food Product Manufacturing (Y.H. Hui, R. Chandan, S. Clark, N. Cross, J. Dobbs, W.J. Hurst, L.M.L. Nollet, E. Shimoni, N. Sinha, E.B. Smith, S. Surapat, A. Titchenal & F. Toldrá, Eds.), vol 2, John Wiley Interscience, New York, pp. 263–277. toldrá, f. & barat, j.m. 2009. Recent patents for sodium reduction in foods. Recent Patents in Food, Nutrition & Agriculture, 1, 80–86. toldrá, f. & flores, m. 1998. The role of muscle proteases and lipases in flavor development during the processing of dry-cured ham. CRC Critical Reviews in Food Science and Nutrition 38, 331–352. toldrá, f. & flores, m. 2007. Sensory quality of meat products. In: Handbook of Food Product Manufacturing (Y.H. Hui, R. Chandan, S. Clark, N. Cross, J. Dobbs, W.J. Hurst, L.M.L. Nollet, E. Shimoni, N. Sinha, E.B. Smith, S. Surapat, A. Titchenal & F. Toldrá, Eds.), vol. 2, John Wiley Interscience, New York, pp. 301–326. toldrá, f., rico, e. & flores, j. 1992. Activities of pork muscle proteases in model cured meat systems. Biochimie 74, 291–296. toldrá, f., flores, m., aristoy, m-c., virgili, r. & parolari, g. 1996. Pattern of muscle proteolytic and lipolytic enzymes from light and heavy pigs. Journal of the Science of Food and Agriculture, 71, 124–128. toldrá, f., flores, m. & sanz, y. 1997. Dry-cured ham flavour: enzymatic generation and process influence. Food Chemistry, 59, 523–530. toldrá, f., aristoy, m-c. & flores, m. 2000. Contribution of muscle aminopeptidases to flavor development in dry-cured ham. Food Research International, 33, 181–185.

© Woodhead Publishing Limited, 2011

526

Processed meats

toldrá, f., sanz, y. & flores, m. 2001. Meat Fermentation technology. In: Meat Science and Applications (Y.H. Hui, H. Nip, R.W. Rogers & O. Young, Eds.), Marcel Dekker Inc. New York, USA, 537–561. toldrá, f., gavara, r. & lagarón, j.m. 2004. Packaging and quality control. In: Handbook of Food and Beverage Fermentation Technology (Y.H. Hui, L.M. Goddik, J. Josephsen, P.S. Stanfield, A.S. Hansen, W.K. Nip & F. Toldrá, Eds.), Marcel-Dekker, New York, pp. 445–458. vestergaard, c.s., schivazzappa, c. & virgili, r. 2000. Lipolysis in dry-cured ham maturation. Meat Science, 55, 1–5. zapelena, m.j., ansorena, d., zalacaín, i., astiasarán, i. & bello, j. 1998. Dry fermented sausages manufactured with different amounts of commercial proteinases: evolution of total free α-NH2-N-groups and sensory evaluation of the texture. Meat Science, 49, 213–221. zapelena, m.j., zalacaín, i., paz de peña, m., astiasarán, i. & bello, j. 1997. Addition of a neutral proteinase from Bacillus subtilis (Neutrase) together with a starter to a dry-fermented sausage elaboration and its effect on the amino acid profiles and the flavor development. Journal of Agricultural & Food Chemistry, 45, 472–475.

© Woodhead Publishing Limited, 2011

21 Improving the sensory and nutritional quality of smoked meat products E. P. Emmerson, Red Arrow Products, USA

Abstract: This chapter explains how liquid smoke can be used to improve the quality of smoked meat products. The chapter first briefly discusses the manufacture of natural smoke condensates, then the various application methods and their advantages are discussed. Key words: liquid smoke, natural smoke condensates, atomization, drenching.

21.1 The process of smoking muscle food products For thousands of years, smoke has been used to preserve and flavor food. Wood smoke has both antioxidant and bacteriostatic properties and it is these qualities that in the past have enabled people to prolong the usable life of perishable food, particularly meat, which has thus helped ensure human survival. This was most often done by exposure to the smoke of burning or smoldering plant materials, most often wood. Other fuels besides wood have been used in areas that wood sources are not readily available, such as peat, corn cobs and in some cases dried animal dung. Various hardwoods (oak, pecan, alder, mesquite, maple, and fruitwoods such as cherry and apple) are most commonly used. Softer woods such as pine and fir have higher quantities of resins, which produce undesirable harsh creosote flavors when burned. More recently, the development of aqueous wood smoke condensates known as ‘liquid smoke’ has resulted in the widespread use of natural smoke flavoring in many food products. Today, smoke flavor can be added to a great variety of products ranging from all forms of meat products, to snack foods, sauces and pet foods using liquid smoke condensates. Figure 21.1 shows a small variety of the products that can be manufactured using this approach.

© Woodhead Publishing Limited, 2011

528

Processed meats

Fig. 21.1 Assorted processed meat products produced using natural liquid smoke condensates.

21.2 Advantages of using natural smoke condensates compared with traditional smoking technologies Natural smoke condensates are produced by controlled pyrolysis (burning) of a wood source, then removing the undesirable tars and resins (which are linked with chemical toxicity and safety issues in the consumption of smoked muscle-based food products), while at the same time maintaining desirable color and flavor components. With the use of natural smoke condensates, food processors are able to obtain several advantages over the traditional method of smoking which requires contacting the food directly with the generated smoke. It is much easier to establish and standardize smoke flavor and color with the use of a natural smoke condensate than to reproduce the traditional vaporous smoking process. Research has shown that the use of natural smoke condensates has improved the consistency of finished smoked products and eliminated the many variables associated with the traditional smoking process. With the use of traditional smoking methods a number of factors can and will affect the smoke cloud that is generated into the cooking chamber. Such things as moisture content of the wood chips used, operating efficiencies of the smoke generating equipment, as well as environmental conditions, all will affect the smoke density which in turns affects the flavor and color profile of the finished product. With liquid smoke condensates all of these factors are controlled during the burning process, and the levels of carbonyls and phenolics are checked before the product

© Woodhead Publishing Limited, 2011

Improving the sensory and nutritional quality of smoked meat products

529

reaches the customer, ensuring that the color and flavor components are consistent for each and every production run. The use of liquid smoke is generally acknowledged to be simpler and more sanitary than dealing with the inconvenience of handling wood; sawdust for example. Smokehouse cleaning chemicals and labor are significantly reduced since most of the tars and resins that traditional smoke generators deposit in the duct work and inside the cooking chamber are removed during processing when using liquid smoke condensates. There is also a saving in the time and cost involved in maintaining smoke generators as well as reducing health and safety risks associated with potential fire hazards. The use of liquid smoke has also provided a solution to the problem of emissions associated with traditional smoking. It eliminates particulate and malodorous emissions to meet the industrial air pollution control regulations; therefore there is no longer a need for afterburners and scrubbers to be present within the smoking process. As an example, Red Arrow Products employed the services of an external test company to assess the discharge emissions from commercial smokehouse so as to ascertain the differences that were considered to be present between; traditional smoking, atomization of smoke condensate and drenching with smoke condensate. Results from this independent investigation showed that the traditional wood smoke cycles released 1.23 lbs (0.55 kg) of total particulate matter (PM) and also produced 2.82 lbs (1.26 kg) of volatile organic compounds (VOC) as propane. The emissions released from a combination of liquid smoke drenching and traditional wood smoke were 0.43 lbs (0.19 kg) of total PM and 0.99 lbs (0.46 kg) of VOC as propane, while the emissions produced from a combination of liquid smoke atomization and wood smoke were 0.54 lbs (0.24 kg) of total PM and 1.73 lbs (0.78 kg) of VOC as propane. These results show that emissions were reduced by over 65% using the smoke drench combination and by 39% with the atomized smoke combination. This demonstrates the reduction in emissions in this particular instance, but emissions may vary depending on the total house and total wood smoke times employed. Consequently, herein lies the advantage of employing a combination process. If a processor was currently using a scrubber, the integration of a smoke drench combination would cut back, if not eliminate, the need for a scrubber to be in operation. The use of an atomized smoke combination would easily decrease the cleaning load placed on labor and equipment. A major advantage of using natural smoke condensates rather than traditional vaporous smoke for smoking meats and other foods is the removal of tars and resins associated with polycyclic aromatic hydrocarbons (PAHs) during the manufacturing process. The results of various surveys of traditionally smoked foods in the US and abroad have demonstrated the presence of PAHs. Reported quantities of benzo(a)pyrene ranged from less than 0.4 ppb in some sausage products, up to 30 ppb in some smoked fish,

© Woodhead Publishing Limited, 2011

530

Processed meats

heavily smoked hams and traditionally smoked salt. With natural liquid smoke flavors, benzo(a)pyrene and nitrosamines are not present in any detectable level. This has led many researchers to recommend the use of natural smoke flavorings as a means of eliminating the presence of potential carcinogens in smoked meats and other food products. Owing to the concentrated nature of natural liquid smoke, smoking times can be significantly reduced. Atomization can reduce overall smoking time by a half. Showering of natural liquid smoke condensate can reduce smoking time to 1 to 2 minutes. With reduced processing times the manufacturer can also gain significant yield savings. Yield savings under showering conditions typically are 2–3%. There will also be a decrease in energy consumption due to shortened processing times, which translate to lower production costs.

21.2.1 Critical smoke components of liquid smoke condensate Traditional wood smoke has been found to contain over 300 different identifiable chemical compounds. In general, all the major chemical compounds of wood smoke, whether using a traditional or a liquid smoke condensate approach, can be grouped into four major groups: acid compounds, phenolic compounds, carbonyl compounds, and PAHs. Hardwoods consist of three main materials: cellulose, hemicelluloses, and lignin. Cellulose and hemicelluloses are aggregate sugar molecules and when pyrolyzed produce carbonyls, which is responsible for the primary color component. Lignin is a complex arrangement of interlocked phenolic molecules which provide most of the flavor components. It is the differences that exist in these four compositional groupings within different wood sources (based on tree species) that account for the quality differences observed in meat and other food products with respect to color, flavor, preservation, shelf-life, etc. Acids The acid compounds in wood smoke contribute more to the physical characteristics of the smoked product in processing (i.e. peelability and protein coagulation) than to smoke flavor or color. The acid in smoke contributes to the skin formation on the surface of wieners in cellulose casings, which aids in casing peeling and the desired bite during consumption. The acid starts the denaturation or protein coagulation and the heat of the cooking process finishes it. The primary acid present in wood smoke is acetic acid. The acid in natural liquid smoke condensate is measured by potentiometric titration. The acids in liquid smoke will range from 0 to 16%, and pH will range from 2.5 to 7.0. Phenolics The phenolic compounds of wood smoke are the main contributors to the typical ‘smoke’ flavor associated with smoked muscle-based products. The

© Woodhead Publishing Limited, 2011

Improving the sensory and nutritional quality of smoked meat products

531

components vary greatly in their flavor characteristics. These phenolics, when identified individually, range from possessing robust to very mellow flavor profiles. The components are measured colorimetrically by the modified Gibbs procedure (Tucker, 1942) and are expressed on the individual product specification sheets as ‘smoke–flavored compounds.’ These compounds are also both antioxidants (which slow rancidification of animal fats) and antimicrobials (which slows bacterial growth). Carbonyls The carbonyl compounds of wood smoke contribute to the formation of the smoked color on the surface of a meat product. The primary reaction in typical smoked meat color is the browning reaction between the carbonyls of the smoke, which are derived from the burning of the cellulose and the hemicelluloses, and the amino groups of the meat protein. The carbonyls in Charsol are measured colorimetrically as 2,4 dinitrohenyl-derivatives by the modified Lappin-Clark procedure (Lappin and Clark, 1951) and are expressed on the individual specification sheets as carbonyls. Aromatic hydrocarbons The fourth group of components found in natural wood smoke are the PAHs. Some of the hydrocarbons are suspected carcinogens, e.g., benzo(a) pyrene. In the manufacturing process of Charsol natural smoke flavors, the tars and resins containing the polycyclic aromatic hydrocarbons are removed from the natural smoke flavors. This provides a definite advantage for using Charsol natural smoke flavors over traditional smoking processes.

21.2.2 Liquid smoke condensate production Charsol (a product produced by Red Arrow Products) natural smoke condensates are produced by a process in which the desirable flavor and color components from hardwood smoke (commonly hickory, maple, oak, and alder) are absorbed in a balanced proportion, while at the same time removing the tar and resin fractions. The final natural smoke condensate colors and flavors meat products without the inconsistency and hazards associated with traditional smoking processes (this is illustrated in Fig. 21.2). Several researchers have also reported that with the use of liquid smoke, shelf-life of meat and fish products is significantly improved over traditionally smoked muscle foods (Lapshin and Shevchenko, 1977). Some of this is due to the elimination of creosote and tar from the natural smoke flavorings. German workers (Pool and Lin, 1982) have shown that smoke flavorings are free of mutagenic activity when the creosote and tar fractions have been removed from natural smoke flavors. They found the smoke flavor phenolic substances to be totally free of mutagenic activity and supported the further development of natural smoke flavors. Kozlowski, (1969) performed a complete toxicological study of natural smoke flavors and showed them to be

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Fresh production tank

Condenser

Fig. 21.2

Final filter

Quality Control Evaluation

...and ends with a healthier and more environmentally friendly natural smoke.

Containerized and sold to meat & food processors

Sawdust dryer

Sawdust generation

Illustration of natural liquid smoke condensate manufacturing process.

Preliminary filter

Smoke generator

Secondary batch tank

Primary tank

Phase separation

Red Arrow’s smoke condensate process stars with nature’s finest woods from managed forest programs...

Improving the sensory and nutritional quality of smoked meat products

533

free from any potential health hazards. Feeding studies (Prier, 1961) and toxicological studies (Lechner, 1977; Nitzke, 1977) carried out on Red Arrow natural smoke flavors showed the absence of any potential health hazards previously reported with the traditional smoking process (Dungal, 1961). From the independent research carried out to date on natural liquid smoke condensates the use of natural smoke flavors offers significant advantages over the traditional method of smoking meat.

21.3

Application methods of liquid smoke condensates to muscle-based food products

Liquid smoke condensates can be applied to muscle-based food products through a plethora of processing techniques, such as: atomization, drenching, internal addition, smoked nets, and spraying systems. The ability of liquid smoke and browning agents to brown or color products are directly proportional to increases in the following controllable factors: temperature, cook time, percent protein, and smoke or browning agent concentration. These approaches and factors are dealt with in greater detail within the subsequent sections below.

21.3.1 Atomization This method of application involves the process of using pressurized air to vaporize liquid smoke. The liquid smoke is released into the nozzle assembly at a controlled rate. At that point a stream of pressurized air breaks the stream into a vaporous cloud. This process is used to simulate the traditional smoking process in a batch smokehouse. This method has several advantages over using traditional smoking processes. The smokehouse stays cleaner because the smoke is not circulated during atomization, the smoke cloud is more concentrated so the smoking time is reduced and often the total schedule time is reduced. Processors can eliminate tar spots on products that can derive from tar build-up that accumulates in the ductwork from the use of traditional generated smoke. The use of liquid smoke condensates can also eliminate water, electric, and maintenance expense associated with traditional smoke generators. Additionally, no further tar and creosote deposit build up occurs in the smokehouse ductwork, which removes fire risks associated with traditional smoke generators. In order for atomization to be successful as a method of application, correct installation of the nozzles in the smokehouse is critical. Nozzles need to be properly placed to allow for the generated smoke cloud to mature and circulate correctly throughout the house. Calibration of the atomization unit is also central to ensuring that a dry vaporous cloud is produced.

© Woodhead Publishing Limited, 2011

534

Processed meats

If a manual atomization unit is used, then only the desired amount of smoke in the house should be atomized. This assures that the liquid feeding lines are cleared of product at the end of the atomization step. The atomization processed should never be based on time unless a deluxe unit is being used. A deluxe unit is built with actuated valves that are controlled via the smokehouse processor which turns the unit on and then purges the line of liquid smoke in accordance to the customers cook schedule. The atomization step should be limited to 30 minutes maximum for bacon and hams, 20 minutes for smoked sausage, 20 minutes for log products or any other product with horizontal surfaces. If additional smoke is needed, a drying step must be incorporated into the process to dry the product and exhaust the house. When atomization begins, the optimum conditions for the muscle food product are to have a surface temperature of 105–115 °F (41–46 °C), to keep product away from the direct smoke stream, and to have the product properly spaced on racks so that the smoke cloud can easily surround the entire product. When using an atomization approach to liquid smoking muscle-based food products, a processing schedule should be outlined as follows: • Drying. This step dries the surface of the product and begins heating it to prepare for atomization. Normal temperature for this step is 140–160 °F (60–71 °C), with ambient humidity at or below 25%. • Atomize. Described above. • Color setting or drying stage. This step allows the smoke components absorbed during atomization to begin reacting with the protein under dry heat conditions.Typical temperatures should be 150–170 °F (66–77 °C) with ambient relative humidity. • Cooking. Temperature and relative humidity are increased to cook the product to finished internal temperature. • Conditioning. This step may be used at the beginning to heat the surface before drying and is most commonly used for large diameter products and for natural casing or collagen casings. This step requires the use of 80–100% relative humidity at dry bulb temperatures ranging from 120 to 130 °F (49–55 °C) and ranges from 10 minutes for large diameter products to 5 minutes for small sausage-type products. Before the unit is used for normal operation it should be calibrated to insure it operates properly and a dry smoke cloud is being produced. It is recommended that the unit is calibrated with water prior to any operation with smoke in case of leaks and to enable accent to the house during atomization to check the quality and consistency of the smoke cloud. Prior to calibrating the system, it is critical to check that the system assembly is correct, that all fittings are tight and that there is an ample supply of dry air available. Before commencing, the pressure tank must be partly filled with water. This allows for smooth operation of the unit and

© Woodhead Publishing Limited, 2011

Improving the sensory and nutritional quality of smoked meat products

535

consequently, the atomization cloud can be more easily checked. Following on, both the regulators and the flow adjustment knobs are turned counter clockwise until they stop. At this point, the smokehouse controls are turned to the smoke position for a Deluxe unit, and then the air supply is switched on. Depending on which nozzle assembly has been placed into the smokehouse, you would then turn the nozzle air pressure (right regulator) until it reaches the appropriate pressure listed below for the nozzle assembly being used. • 50–60 psi (0.34–0.41 mpa) for a 13b nozzle • 60–70 psi (0.41–0.49 mpa) for a 23b nozzle • 80–90 psi (0.56–0.62 mpa) for a 43b nozzle Once the nozzle pressure has been set, the air pressure is slowly increased to the tank until liquid begins flowing through the flowmeter. The liquid reaching the nozzle and the flowmeter ball is allowed to steady before further adjustment. This may take 1–3 minutes depending on how long the liquid line is from the unit to the nozzle. When the flow is steady, tank pressure is slowly increased until the flow is slightly above the recommended set point for the flowmeter. Recommended set points vary depending on the nozzle size, but starting points are as follows: • 1–1½ gph (gallons per hour) for a 13b nozzle • 2–3 gph for a 23b nozzle • 4½–5½ gph for a 43b nozzle Following this step, the flow meter is adjusted until the indicator reaches the desired flow rate. Once the desired flow rate is reached, the dryness of the cloud must be assessed. The cloud should feel dry 2–3 ft (0.6–1 m) from the nozzle tip, with little or no moisture condensing on your hand, as you slowly pass it through the vaporous cloud (see Fig. 21.3). Once satisfied that the cloud is dry, the door to the smokehouse is closed and this allows the smokehouse to fill up with the vapor cloud. The thickness of the cloud can be assessed by shining a light into the smokehouse itself (for example, using a flashlight). Light should not be able to penetrate more than 3–5 (1–1.6 m) feet. Special attention should be paid to the corners and around the top of the smokehouse, making sure that the vaporous cloud is equally distributed throughout the smokehouse. The velocity of the vapor stream at the facing wall or corner should be checked. If the velocity is too high the stream may cause a swirling effect and this condition would cause the product on the rack in that corner to become darker than the remainder of the products held in other positions in the smokehouse. If necessary the nozzle pressure may require a reduction as well as a reduction in the flow rate. After the unit is calibrated and you are satisfied that all the above conditions have been met, all the water should be blown out of the liquid lines with air pressure before operating with smoke. This eliminates any mixing

© Woodhead Publishing Limited, 2011

536

Processed meats

Fig. 21.3 Vaporous cloud produced by an atomization nozzle.

of smoke and water in the lines which would result in smoke separation and tar build-up and which could potentially clog the atomization nozzle.

21.3.2 Calibration of a deluxe panel After activating the atomizer with the smokehouse controls, the calibration procedures described above should be followed. Once calibration is complete and during the purge cycle, the internal purge regulator must be set. This regulator controls the air pressure that is used to purge any remaining liquid smoke out of the supply line at the end of the smoking step. This regulator needs to be set at a pressure that keeps the flow rate the same or slightly lower than it is during the atomization step, thus allowing for a controlled purge of the smoke from the lines.

21.3.3 Maintenance of atomization units The POWRSMOKER atomization unit is designed for easy cleaning and low maintenance upkeep. With a few minutes of care each week, the POWRSMOKER should operate without encountering any technical difficulties.

© Woodhead Publishing Limited, 2011

Improving the sensory and nutritional quality of smoked meat products

537

Cleaning the atomization nozzle(s) It is important that atomization nozzle(s) are disassembled regularly (at least once a week) and air caps and fluid cap inspected; cleaning any blockages that may restrict air or liquid flow. These blockages may result from liquid smoke that has dried in the liquid line, a worn-out nozzle gasket, or from other particulates that may enter the system. A clean nozzle will ensure a proper air and liquid mixture for atomization. When reassembling the nozzle, it is important to ensure that the air cap opening (slot) is in the proper vertical or horizontal position. This positioning is determined by where the nozzle is placed, either along a side wall (vertical), or near the floor (horizontal). Cleaning the POWRSMOKER For the system to continue to operate properly it is imperative that it is cleaned routinely. Cleaning is necessary not only for the proper operation but also to extend the life of the system components. Normally, weekly cleaning is adequate to keep the system free of smoke build-up. The following procedure will insure that the entire system is clean and ready for operation. Red Arrow recommends this important procedure be used weekly as a routine measure and is as follows: • Before removing or disassembling any component parts, air and liquid pressures must be relieved. • Remove the air cap, liquid cap, nozzle gasket and locking ring from the nozzle assembly and soak in a recommended dilution of a caustic cleaner. This will dissolve and remove any liquid smoke that may have built up on the nozzle during the course of production. • Assure the house is empty of meat products and close the smokehouse doors. • Pour about 1 gallon (3.8 liters) of the same diluted caustic cleaner into the pressure tank. • Turn the atomization system on and turn the three-way valve to the closed position. • Allow the liquid in the tank to flow through the system as normal except that the flow rate will be much higher due to the nozzle being removed (this will then dissolve and remove any liquid smoke build-up that may be present). • When the liquid has emptied from the tank allow the air pressure to blow the residual liquid from the lines for a few minutes before shutting the system off. Then rinse the pressure tank out with potable water and put 1–2 gallons (3.8–7.6 liters) of additional water in the tank. • Turn the system back on and allow the water to flow through the system to rinse out any remnants of the mild caustic solution that was used for the cleaning procedure. • Critically, again allow the air pressure to blow the residual water from the lines for a few minutes before shutting the system off (it is very

© Woodhead Publishing Limited, 2011

538

Processed meats

crucial that ample time is allowed for the air pressure to blow as much free water from the system as possible and will help to prevent plugging of the nozzle once liquid smoke is introduced back into the system). • Rinse the nozzle parts off in potable water and install on the nozzle block making sure that the Teflon gasket is in good shape and the nozzle air cap is oriented properly. • Now the system is ready for operation again. However, as with all technologies, difficulties arise which are problematic and not easily determined. Consequently, Red Arrow has provided a trouble-shooting guide to help with determining and addressing technical issues associated with the use of the POWRSMOKER and these are supplied in Table 21.1.

21.3.4 Drenching Drenching is any process that allows smoke to completely saturate the surface of a meat product (see Fig. 21.4). Drenching is a very efficient form of topical smoke application because the smoke is reused and it does not require the smokehouse to be shut down during the smoke application. This application can be achieved using nozzles, drench pans, or cascade pans. Each of these methods of application use a high volume, low pressure circulation system to provide a complete and total shower of liquid smoke solution over the product. Drenching systems are generally equipped with macro-filtration (to catch large particles), in the form of sump screens placed over the top of the sump, and micro-filtration (to catch smaller particles). The micro-filtration can be in the form of manual filters or automated filters that are placed in the circulation system prior to the pans or nozzles. Advantages over atomization One of the greatest advantages of using liquid smoke drenches is that it allows for increased product throughput by shortening cook schedules. As a consequence of this approach, cook schedules can usually be reduced by 30–40% or more for products like hotdogs or smaller sausages. In addition the smokehouse stays cleaner because smoke is not applied in the heating portion of the smokehouse. This helps increase smokehouse life because smoke does not come in contact with the smokehouse or its components. Another advantage is that finished products tend to be more uniform in appearance, since the entire surface gets evenly covered by the smoke solution. Consequently, skin formation is started on the product during the drenching process when the acids in the liquid smoke solution commence protein coagulation at the product’s surface. This allows higher humidity levels to be introduced earlier in the cook schedule, thereby increasing

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

• Inadequate air supply to the unit • Blockage in the air line or nozzle • Quick disconnect on the air line is blocked • Air and liquid lines are reversed to the nozzle • Tank pressure is too low • Flowmeter is closed • Tank quick disconnects are blocked • Blockage in the liquid line or nozzle • Liquid and air lines to the nozzle are reversed • Air path is restricted • Flowmeter is set too high • Nozzle air pressure is too low • Uneven plant air pressure • Tank pressure is set too high • Liquid flow is too low • Nozzle is blocked • Liquid flow is inadequate • Smoke cloud is too wet • House is too large for single nozzle assembly

Insufficient air pressure to the nozzle

The flowmeter falls below the set point while atomizing Liquid comes out of only one nozzle (Dual-V nozzle) The smoke cloud is not very dense inside the house

Smoke cloud is too wet

Insufficient liquid flow to the nozzle

Cause

POWRSMOKER trouble-shooting guide

Symptom

Table 21.1

• • • • • • • • • •

Check for kinked air lines or blockage in the nozzle Adjust flowmeter Adjust regulator Install larger supply air line Recalibrate atomization unit Recalibrate atomization unit and increase liquid flow Remove nozzle and inspect for blockage Recalibrate atomization unit; increase liquid flow See above Re-evaluate nozzle set-up; additional nozzle may be required

Recalibrate unit Open flowmeter Replace quick disconnects Remove nozzle and inspect for blockage, inspect liquid line for crimps • Check for proper orientation to the nozzle

• • • •

• Increase size of supply air line to unit • Remove nozzle and check for blockage, inspect air line for crimps • Replace quick disconnects • Check for proper nozzle line orientation

Correction

© Woodhead Publishing Limited, 2011

Finished product color is muddy

There is a white film on natural casing sausage after it is cooked

The tops of horizontal surfaces of cooked product are darker than sides and bottom (Rocker dog) Top to bottom and side to side color on each rack is inconsistent

• Product is not dried properly before smoke application • Too much moist heat during color setting stage of cycle

• Smoke cloud is too wet • Space between product and wall is too small • Atomization nozzle is aligned improperly • Smoke cloud is too wet • Smoke is spraying from nozzle after atomization is ended • Product is not dried properly before smoke application • Smoke cloud is too wet • Product is not dried properly before smoke application • Product is not dried properly before smoke application • Air flow in smoke house is not balanced properly • Undissolved smoke components deposited on surface

Cooked product is darker near the nozzle

Cooked product has dark spots

Cause

Continued

Symptom

Table 21.1

• See above • Verify surface temperature is ∼105–115 °F at atomization • Verify surface temperature is ∼105–115 °F at atomization • Consult with smoke house maintenance personnel to balance air flow in house • Lower application rate • Use a smoke with polysorbate such as Select 24P or Supreme Poly and dilute with water to 80% concentration • Verify surface temperature is ∼105–115 °F at atomization • Use more dry heat after atomization

• See above • Keep air on until smoke tank is depressurized • Verify surface temperature is ∼105–115 °F at atomization

• See above • Leave ∼12″ (300 mm) between wall and product surface • Check for alignment and adjust as necessary

Correction

Improving the sensory and nutritional quality of smoked meat products

541

Fig. 21.4 Liquid smoke shower produced from a drench pan.

cooking efficiencies and higher cook yields. Finally, smoke is filtered and reused during the course of the production week, thus increasing the efficiency of the smoke. Factors that will affect the success of drenching As in the case of using atomization for smoking, various factors will affect the performance of using drenching as an approach to smoking musclebased food products: • Concentration of the smoke used. Smoke concentration is tracked by titrating the acidity of the smoke solution; the higher the smoke concentration, the higher the absorption of smoke components by the musclebased product in question. • Proper addback level of pure liquid smoke condensate. As product passes through the drench, it absorbs smoke components. Consequently, additional components need to be continually added through the course of production. These components must be replaced to ensure the proper concentration is maintained throughout the production cycle. • Contact time of the drench. The higher the drench contact time with the product in question, the higher the absorption rate. However, this has a limiting factor of about two minutes, so drench times for products longer than two minutes will result in no additional gain in smoke components by the product. • Filtration of liquid smoke. This is carried out to insure that the smokedrenching system is not impeded by meat, fish or other food debris, which can build up inside of drench pans or nozzles, thereby blocking the flow of the smoke solution over the product.

© Woodhead Publishing Limited, 2011

542

Processed meats

Developing a smokehouse schedule for a drenched muscle-based product The smoke schedule commences with a dry heating step using a relative humidity of 28% or less, until product color is set (produced by carbonyls binding with the meat/fish proteins). Then the relative humidity can be increased, which provides a greater efficiency of heat transfer and faster cooking times. Because a skin has developed on the product, the product can usually be heated much quicker than with atomization or traditional smoke. However, unlike these two methods, steam or heat cannot be administered prior to the color being set, or the carbonyls will not bind efficiently with the meat proteins; resulting in little or light color development in the finished product. This color set usually occurs when the surface temperature of 130 °F (55 °C) is obtained. Determining the acidity of the smoke Acidity is measured to determine the level of components in the smoke solution. Acid is only one of the components present; carbonyls (color) and phenols (flavors) are the other two components present in liquid smoke. In a drenching solution these three components will remain in a linear relationship, so if the acid level increases or decreases, the flavor and color levels will follow the same trend. A producer will determine what concentration of liquid smoke solution provides the flavor and color profile they desire. Acid is the easiest to test at plant level, so titrating the acidity of the liquid smoke to determine what percentage of the sump solution is smoke is carried out and this provides a better idea of what the carbonyl and phenol levels are, thus providing processors with a simple approach to controlling consistency in their finished product. Titrating the liquid smoke can be done quite easily and the procedure is as follows: 1. Obtain a sample of smoke solution. 2. Pipette 2 ml of smoke solution into a 400 ml beaker. 3. Add distilled water (deionized will also suffice) to the 100 ml mark on the beaker. 4. Place stirring bar in sample and begin mixing. 5. Position pH meter probe to allow continuous reading without being struck by stir bar. 6. Fill burette with sodium hydroxide. 7. Begin adding sodium hydroxide to sample, allowing time to mix sufficiently. 8. As pH approaches 6.0, begin adding sodium hydroxide more slowly to avoid raising the pH beyond 7.0. 9. When pH = 7.0, record the amount of sodium hydroxide dispensed. 10. Determine percent of acid in sample using the following formula: % acetic acid =

ml NaOH added × normality of base × 0.001 × 60 × 100 ml smoke tested

© Woodhead Publishing Limited, 2011

Improving the sensory and nutritional quality of smoked meat products

543

where (.001) is a conversion factor and (60) is the molecular weight of acetic acid. 11. Record the following information: time sample was taken, product being processed, smoke product being used, target acidity, ml base dispensed, percent acidity, and any action taken.

21.3.5 Internal addition Of all of the approaches used to liquid smoke muscle-based food products, internal addition is the most efficient method in terms of adding smoke flavoring to such products. Internal addition will produce uniform flavor throughout the interior of the product which cannot be achieved through other application methods. However, internal addition will not produce any surface color, unlike that produced by atomization and drenching applications. The advantages that internal addition has over drenching and atomization methods is that no application equipment is necessary. The flavoring can be added as part of a spice blend, can be added directly to the brine solution before pumping, or added directly to the meat emulsion itself. Using an internal addition produces uniform smoke flavor throughout the inside of the meat product. Consequently, antioxidant action within the product is greatly enhanced using this approach. Internal addition of liquid smokes can be used in ‘Cook in the bag’ products, and upon cooking, there is no disposal of liquid smoke after processing is complete. When this approach is used to smoke muscle-based products, the product label must state ‘Smoke flavoring added’. Internal addition of liquid smoke can be divided into two approaches; direct addition and brine injection. Direct addition This method is used for sausage emulsion products. Liquid smoke condensate is added directly to a bowl chopper or mixer during the mixing process. To aid dispersion, it is recommended that the smoke is added to a portion of the water prior to mixing, due to the relatively small amount of liquid smoke used in a batch; this facilitates a more even product dispersion. Brine injection In this method, the liquid smoke condensate is added to the brine that is injected into cured products such as hams or bacon. A neutralized smoke (i.e. neutral pH) must be used because of the nitrite in the salt brine; acid will break down the nitrite into nitrogen dioxide gas which can be lethal if produced in large quantities. In addition, the nitrite will not be available for the curing reaction and this would equally raise concerns over product quality as well as safety. Neutralized varieties of smoke condensates must be dilutable in water since they will be mixed into the salt brine solution.

© Woodhead Publishing Limited, 2011

544

Processed meats

21.3.6 Smoked nets This is the process of applying liquid smoke condensate to meat binding nets before they are placed around the outside of the product. When the smoke condensate is transferred into a gaseous state from the nets during heat processing it is considered a natural smoking method by the United States Department of Agriculture (USDA) and consequently, such products do not have to be labeled differently from traditional wood smoked products. It should be noted that smoked nets can be difficult to remove after processing, and the cooked product can be slightly muddy due to the surface not being dried before the smoke is applied. The primary advantage of using smoked nets (over atomization or drenching) is that no additional application equipment is necessary. Smoke nets simply replace the current unsmoked nets. In addition, processing times are often shorter (compared with atomization) since the smoke application step is eliminated.

21.3.7 Spraying systems This approach, as the name suggests, involves spraying liquid smoke or browning agents directly on the product surface before or after the cook. If the application occurs before the cook, there are no extra labeling requirements. If it is applied after the cook, it is subject to the qualifying statement of ‘smoke flavor added’, or in the case of MB 12 ‘caramel color added’. The advantage that spraying systems have over injection is that there is no premature liberation of nitrite due to nitrite reaction being complete. Additionally, smoke flavor can be tightly controlled and this can be done either by changing the solution strength or by changing the application rate. Further advantages are that the use of neutralized smoke is not required since the cure reaction has already happened and there are no labeling restrictions as long as smoke is applied before the cooking process.

21.4 Conclusions and future trends In conclusion I have tried to provide an overview of how the smoking process of food products works and the advantages that the use of natural liquid smoke condensates can provide to food processors. These advantages come in the form of consistency, shortened processing times, lowered emissions, easier clean-up, minimal maintenance costs, and a wide variety of products and application methods that are available to food processors to name a few. These advantages apply to large and small producers alike, allowing them to maximize profitability and enhance food safety. The future of natural liquid smoke condensates is wide open as new processing technology allows for more products to be continually developed. Currently,

© Woodhead Publishing Limited, 2011

Improving the sensory and nutritional quality of smoked meat products

545

natural liquid smoke condensates range from products that are all flavor and no color to products that are all color and no flavor, there are also grill and reaction flavors that further expand the options available for producers to incorporate into their production. To learn more about available smoke, grill, browning, and reaction flavors please visit www.redarrowusa.com.

21.5 References and further reading dungal, n. ‘The special problem of stomach cancer in Ireland’ J. Amer. Med. Assoc., 178(5): 93–102, 1961. howard, j.w. and t. fazio. ‘Analytical methodology and reported findings of polycyclic aromatic hydrocarbons in foods’ J. Assoc. Off. Anal. Chem., 63: 1007–1104, 1980. kozlowski, a.p. ‘Investigations of the chemical, toxicological, and biological properties of the Polish smoke extract’ Proc. Eur. Mect. Meat. Res. Work, 15: 516–524, 1969. lappin, g.r. and l.c. clark. ‘Calorimetric method for determination of traces of carbonyl compounds’ Anal. Chem., 23: 541–542, 1951. lapshin, i.i. and m.g. shevchenko. ‘Changes in nitrogenous substances during the manufacture and storage of dried fish products’ (In Russian) Food Sci. Tech. Abstr., 9: 7R338, 1977. lechner, r. Report on Analysis of Polynuclear Aromatic Hydrocarbons in CharSol, WARF Institute to Red Arrow Products Co., 1977. nitzke, n.j. Report on Ames Mutagenicity Test on CharSol, WARF Institute Report to Red Arrow Products Co., 1977. pool, b.l. and p.z. lin. ‘Mutagenicity testing in the Salmonella Typhimurium essay of phenolic compounds and phenolic fractions obtained from smokehouses smoke condensates’ Fd. Chem. Toxic, 20: 383–391, 1982. prier, r. Essay report from Wisconsin Alumni Research Foundation to Red Arrow Products, Co., 1961. shevchenko, m.g. and i.i. lapshin. ‘The effect of smoking dried fish products on the stability of lipids to oxidation’ (in Russian) Food Sci. & Tech. Abstr., 8: 11R691, 1976. tucker, i.w. ‘Estimation of phenols in meat and rat’. J. Assoc. Off. Agric. Chem., 25: 779–782, 1942.

© Woodhead Publishing Limited, 2011

22 Online quality assessment of processed meats M. O’Farrell, SINTEF, Norway

Abstract: This chapter discusses some quality parameters that are typically measured in the processed meat industry and the various online techniques that are currently deployed or investigated. It includes methods that analyse the meat composition, assess the visual and physical appearance of the product and check the safety of the product. The chapter also details future trends and challenges that are found in the area of online quality control in meat processing. Key words: quality monitoring, spectroscopy, online measurements, machine vision, electromagnetic spectrum, meat composition, meat processing, colour, meat attributes.

22.1 Introduction Processed meat includes products ranging from those with a minimum of 30% meat, to products that comprise 100% meat. Processing can be defined as preparation of meats for value added products. This can include portioning, forming and processing procedures such as emulsification, salting, curing, marinating, cooking, smoking or drying. In terms of quality assessment and process optimisation, it is imperative that the quality of the ingredients used, the production process itself and the final products are carefully monitored. This includes evaluating the fat, water and protein content, pH and colour of the meat, parameters such as temperature, colour, salt content and water content during the process and finally, the colour, form, defects and packaging quality of the final product. Integration of this information is both critical and challenging when striving for full process automation and standardisation. This chapter discusses some quality parameters that are typically measured in the processed meat industry and the various online techniques that are currently deployed or being investigated. There is also a discussion on

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

547

future trends and challenges in terms of applications and technological development.

22.2 Meat composition and attributes 22.2.1 Background Meat primarily comprises protein, water and fat. Recipe optimisation requires knowledge of these constituents in order to achieve consistency in the process line and effective use of the raw materials available at the time. An example of this is measuring fat content in processed meat products. The benefit of fat content measurement is twofold; it is indicative of the quality of meat in terms of the recipes used in the process, e.g. pork trimmings used in sausage making and beef trimmings used for hamburgers, and it is has a monetary value since meat has a higher selling price than fat. Fat measurements are often performed after deboning and cutting of the meat. If further processing of the meat is carried out at a different plant, it is possible that the measurement will be repeated. It is, therefore, considered a critical product parameter. It is also beneficial to have knowledge of other meat attributes such as water content, water-holding capacity (WHC) and tenderness (related to water content and connective tissue content). WHC is dependent on the pH of the meat and has a direct impact on product yield and quality. WHC is the ability of meat to retain its water during processing, storage and cooking. Low WHC often results in high drip loss, poorly cured products and low eating quality, i.e. the meat is dryer and tougher after cooking. This section details online techniques that are currently used during meat processing for assessment of meat composition, such as near infrared (NIR) spectroscopy; X-rays and microwaves.

22.2.2 Online techniques NIR spectroscopy NIR spectroscopy is an important analytical tool used in the processed meat industry, in particular in the determination of fat, protein and water content. It extends from 780 to 2500 nm and measures molecular vibrations that are overtones or combinations of fundamental overtones in the mid-IR. In theory, it is possible to measure meat constituents accurately using NIR spectroscopy, but in reality, the absorption information can be hampered by changes in the spectra due to the physical properties of the product and therefore, requires referencing by some other method, such as nuclear magnetic resonance (NMR). NMR is frequently used to build calibration models by matching the NIR measurements with accurate reference values. Many commercial online NIR systems are based on diffuse reflection, causing the accuracy to be more dependent on the homogeneity of the

© Woodhead Publishing Limited, 2011

548

Processed meats

measurand, as the information is taken only from the surface of the product (Togersen et al., 1999). Online systems such as the MM710 Backscatter Sensor by Infrared Engineering Ltd, UK, the FoodScanTM by Foss Tecator AB, Sweden, or the APIS Spektron Meat Optimiser from Prediktor AS can monitor the fat content of products such as ground meat, chocolate, cheese, and cereals; again products with high homogeneity where the fat is distributed evenly throughout the food. Transmission-based measurements are also an option, where detection and illumination are on either side of the meat, but this requires a short optical path between the illumination and detection for ample signal strength. The limiting associated factor here is that only a small amount of product can be monitored at a given time. This method is used in the Wolfking Continuous Fat Analyser, where a narrow stream of meat is sampled from a meat mixer. This is suitable for homogeneous meat since only a small portion of the meat is actually measured and it must be representative of the entire mixture. The main challenge with NIR is that it is very dependent on the quality of the calibration. Interfering parameters that can affect the spectra must also be monitored, for example the temperature of the meat influences the water peak, which undergoes a shift with changing temperature (Ottestad et al., 2009). There is also the problem with varying concentrations of salt used in meat, which also causes a shift in the water peak. Begley et al. (1984) applied the NIR technique to measure the amount of NaCl in canned cured hams. A high correlation between salt content determined by chemical analysis and by NIR spectra at 1806 nm was obtained. The ability of NIR to measure salt content was due to a shift in the water spectrum caused by salt-induced changes in the amount of hydrogen bonding. While this phenomenon is beneficial when measuring the salt content in meat (Lin et al., 2003), it has a negative effect when the NIR system is calibrated to measure the fat content as the fat peak at 920 nm is very close to the water peak around 970 nm. Such effects must be monitored when using NIR for quantification. X-rays X-ray technology is used in the meat industry to monitor the target lean ratio of inhomogeneous meat trimmings. The measurement is based on the fact that absorption at low X-ray energies (around 62 keV) is dependent on fat and areal density, or mass per unit area, whereas the absorption at high X-ray energies is only dependent on areal density. One problem with this method is that X-ray is polychromatic, so penetration of the sample is dependent on the thickness, introducing non-linearities in the relationship between high and low absorption (Brienne et al., 2001). This has been addressed by introducing two separate X-ray sources (Hansen et al., 2003), thus creating two separate images of the sample, and then applying multivariate analysis to the relationship between the two images. The alignment of the two images is also critical for system accuracy; therefore it is

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

549

dependent on the speed of the belt. This system has proven itself to be accurate (root mean square error of prediction (RMSEP) = 0.34–0.44) when averaging over large batches of boxed inhomogeneous samples (9 × 27 kg boxes), with slightly reduced accuracy (RMSEP = 0.57) when individual boxes were measured due to a systematic bias. Smiths Detection is a supplier of dual energy X-ray systems (EAGLETM FA 720) for measuring fat content in 100% of the meat with an error of less than one percent of lean content. It can also be used on frozen meat. The system is typically applied to previously boxed meat and therefore, indicates the average current fat value for the batch against a target fat value. This means that while the average fat percentage of the batch may be near the target, individual boxes can be above or below a target fat value. Since the meat is already packed, it is not possible to adjust the fat level. The main challenges/drawbacks for this technique are the target accuracy at the individual box level, the cost of the system (which is significantly higher than alternative NIR techniques), the requirement of skilled maintenance people and integration of the system into the production line, since the source and detectors must go on opposite sides of the conveyor belt, and both the belt and meat containers must have low X-ray absorbance. Microwaves Guided microwave spectroscopy (GMS) uses very low-powered microwave energy to analyse the physical and chemical properties of a sample. Microwave has a greater depth of penetration than NIR and measures the orientation and relaxation of polar molecules, such as water. In GMS, an alternating microwave signal is sent through a chamber, which ensures constant sample thickness and guides the microwaves through the sample and to the detector. In the presence of microwave energy, the polar molecules in the meat, i.e. water molecules, rotate and align with the applied field. The applied signal is alternating, resulting in polarising and depolarising of the molecules, causing the microwaves to be attenuated. Simultaneously, the microwaves are also reduced in velocity due to friction between moving molecules. The dielectric properties of the meat are closely correlated to the water content and therefore can be used to measure water content and indirectly measure fat content (since fat has a lower water content than meat). The InAlyzer system, using the Thermo Scientific GMS, is an in-line, multi-constituent analyser that monitors any process flowing through a pipeline. This system is incorporated in many Nortura SA cutting lines throughout Norway, where the system is typically used on batches of 1000 kg. It can be sensitive to the speed at which the ground meat passes the sensor; the slower it passes, the more heavily it is weighted in the estimation of the batch average. Again, this analytical technology requires homogenised meat to pass through the chamber and it is also unsuitable for measuring the fat content of frozen meat since the water molecules are not free to move.

© Woodhead Publishing Limited, 2011

550

Processed meats

22.2.3 Future trends and challenges Online interaction Advances have been made by a company called QVision AS in Norway in the area of online interactance NIR measurements for the fish and meat industry. Interactance is a compromise between transmission, where detection and illumination are on either side of the meat, giving the light more time in the product to absorb information, and reflection, where illumination and detection are on the same side allowing the light to absorb information only at the product surface. The QVision AS QMonitor achieves up to 2 cm light penetration into meat, while detecting the light at the same side of the belt. The scanner comprises NIR optics for the interactance measurements and the scanned images have 15 wavelengths for each pixel. QVision has installations that determine the fat content of salmon (Bremnes Seashore in Bremnes), water content of cod (Andreas Bjørge in Ålesund) and fat content in roughly ground beef (Aasheim Kjøtt in Solbergelva). The technique has also been applied to frozen salmon samples, to measure ice and fat content in superchilled salmon (Ottestad et al., 2009), indicating the possibility of applying this system to frozen products. QVision AS is currently investigating the application of the technology to whole beef and pork trimmings (O’Farrell et al., 2010) to allow removal of the standardisation stage, which involves mincing and therefore, a reduced WHC. This technology is substantially cheaper than X-ray and allows fat measurements earlier in the cutting line. Figure 22.1 shows a fat map created by the QVision AS scanner for trimmings of low, medium (high connective tissue content) and high fat. The colour scale is from 0% (black) to 80% (white)

5 10 15 20 25 30 35 40

15 20 25 30 35 40

15 20 25 30 35 40 45 50 15 20 25 30 35 40 45

5 10 15 20 25 30 15 20 25 30 35 40 45 50

Fig. 22.1 NIR fat maps for inhomogeneous trimmings (courtesy of QVision AS).

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

551

fat. The system is suspended over a conveyor belt and scans 200 lines per second. If the belt travels at 1 m s−1, this gives a spatial resolution of 0.5 mm in the direction of the belt movement. The spatial resolution across the belt is 1 cm. Functional foods Typically, the adipose tissue in pig, sheep and cattle contains saturated (35–50% approx.), monounsaturated (30–50% approx.) and polyunsaturated (1.4–16% approx.) fatty acids (Wood et al., 2007). As the benefits of polyunsaturated fatty acids, such as omega-3, become more widely known, knowledge of the fatty acid content in processed meats is becoming more important to the customer. The fatty acid composition of meat can be increased through feeding or through addition to the final product, as in the case of ‘God og Mager Postei med Omega 3’, a liver pâté product by Norwegian company Gilde (made with pork and pork liver and added omega-3). Current techniques for measuring fatty acids include gas chromatography and Fourier transform spectroscopy, both of which are laboratory-based systems. Development of online techniques for quantifying the fatty acid content has significant market potential in terms of pricing superior quality products. Investigations have been carried out using NIR spectroscopy to measure fatty acid content in olive oil (Mignani et al., 2008). A correlation of 0.91 was obtained between the absorption spectrum of olive oil and the percentage of oleic acid. Oleic acid is one of the main fatty acids found in beef and Fig. 22.2 shows its absorption spectra at room temperature (Albuquerque et al., 2003). (a)

7

Transmittance (arb. units)

2 3 4

8

9

10 11

9

10 11

5 6

(b) 3 4 (c)

1

6

5

7

2 3 4

4000

3500

3000

8

8

5

6 2500

2000

1500

9

11

1000

Wavenumber/cm–1

Fig. 22.2 Room temperature absorption spectra in the range 650–4000 cm−1 of: (a) oleic acid, (b) palmitic acid and (c) Buriti oil (Albuquerque et al., 2003).

© Woodhead Publishing Limited, 2011

552

Processed meats

Raman spectroscopy, which has also shown potential as a method for measuring fatty acids (and other meat characteristics such as amino acid and cholesterol content), is now being further explored for online applications (Schmidt et al., 2009). Raman spectroscopy is based on Raman scattering, or inelastic scattering. One of the main advantages of Raman spectroscopy is its immunity to water, which can often interfere in NIR spectroscopy measurements. One of the main challenges in making this suitable for online measurements is the relatively low signature signal in comparison to the excitation laser signal. Herrero (2008) provides an overview of Raman spectroscopy and its potential for usage in the meat industry.

22.3 Visual inspection of products 22.3.1 Background Consumers’ attitudes towards food are very dependent on its colour (Clydesdale et al., 1992). In the customers’ eyes colour is correlated with freshness, so the importance of having an appetising product colour, especially a colour that matches consumer expectations, should not be underestimated. Barbut (2001a, b) found that panellists were so strongly influenced by apparent colour that they preferred the colour of meat when it was illuminated by an incandescent light, as opposed to illumination by a fluorescent or metal halide light, because the red colour under incandescent lighting was more appealing. Colour is also essential in meat processing. Both nitrites and nitrates are used in curing meats, e.g. in the manufacture of ham, bacon, bologna and frankfurters. They produce pigments that are more heat stable (Honikel, 2008). The reactions of nitrite in meat affect the rate and/or extent of cured colour development (Sebranek and Bacus, 2007). The pigments responsible for the pink colour of cured and heattreated meat products are nitrosylmyoglobin and denatured nitrosylmochrome, respectively, and it has been shown that when these pigments are exposed to light and oxygen, they oxidise to metmyoglobin (Moller et al., 2003; Honikel, 2008), causing exposed meat surfaces to fade to a pale grey colour that is unappealing to consumers. For any producer in the food industry, there is a need for some type of colour monitoring to ensure that the colour of the food conforms to consumer expectations and, hence, maximises sales. Despite advances in imaging and spectroscopic techniques, colour is still often measured subjectively by technicians or general operators based on colour standards such as the Japanese or American Pork colour standards used for the detection of aberrant colour, two-toning and pale soft exudative (PSE) or dark firm dry (DFD) meat. Other important physical parameters in terms of product appearance are shape and size. These are important in the processed meat industry where products are made to specific and repeatable weights and

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

553

shapes, e.g. sliced products, nuggets, patties, sausages etc., or in the case where products are picked from a line and placed in packaging. This section details systems that incorporate spectroscopy in the visible region (VIS), machine vision or both to evaluate physical quality parameters in meat and meat products.

22.3.2 Online techniques VIS spectroscopy Reflectance spectroscopy in the visible region of the electromagnetic spectrum holds information that defines product colour. VIS spectroscopy can provide information about the pigments existing in the meat that absorb light, e.g. myoglobin. This spectrum can either be used and based on absorption to measure pigment concentration (Folkestad et al., 2008) or can be related to how the eye perceives colour by measuring the reflected spectrum and using the eye’s response curves. Hunt (1991) discusses an experiment for trichromatic matching, which was developed by the Commission Internationale de l’Eclairage (CIE). The Red Green Blue (RGB) and XYZ tristimulus colour spaces were first created in 1931. The three-dimensional L*a*b* colour space, which is an extension of the XYZ colour space, was developed in 1976 and is most similar to human perception of colour. It is frequently used in the meat industry. Achieving repeatability in calculating tristimulus values absolutely from a spectrum requires accurately measuring both the shape and intensity of the spectrum. Intensity is a notoriously difficult parameter to measure in terms of repeatability as it is dependent on so many factors, including; light source stability, angle of illumination/ detection and surface evenness and texture. As stated in an application note provided by HunterLab, developers of systems commonly used for offline meat colour measurements (Hunterlab Associates Inc., 2008): ‘The ideal sample for instrumental colour measurement would be completely opaque, uniform, flat, smooth, non-directional, homogeneous, and at least slightly larger than the instrument measurement port. Samples that are not completely flat can be flattened by pressure at the measurement port.’ This makes online measurements very difficult and internal measurements virtually impossible. Minolta and HunterLab have developed solutions based on colorimeter technology. Colorimeters take three wideband spectral energy readings in the visible spectrum by using filtered photodetectors. They are, therefore, not based on the full spectrum, as in the case of spectrophotometers. The Minolta CR–210 colorimeter is an offline method, very often used as a standard for monitoring the meat colour, whereas HunterLab has also developed an online solution, ColourTrend, which has had success in online colour monitoring of nuts, coffee beans and baked goods, but not meat colour. The ColourTrend is more suitable for routine comparisons of similar colours.

© Woodhead Publishing Limited, 2011

554

Processed meats

The Hennessy grading probe, used for classification of animals, is based on reflectance spectroscopy. The measurements are taken from the slaughtered animal by insertion of the probe followed by slow withdrawal and are therefore less susceptible to inaccuracies due to uneven surfaces. The fact that the probe end is in contact with the meat or fat makes it more of an interactance reading than pure reflectance reading, measuring the level of pigment absorbance in the meat against fat. It can measure the depth of the subcutaneous fat for lean meat yield prediction in cattle, sheep and pigs and the paleness of the muscle for porcine spongiform encephalopathy (PSE) detection in pigs; however, it has not been as successful in measuring intramuscular fat (marbling). The probe must be inserted in a particular way to obtain suitable readings (Fig. 22.3). Similar products on the market include; Fat-O-Meat’er and the Destron PG-100. For the detection of PSE, the Hennessy Grading Probe is used to measure the reflectance of the loin muscle approximately 45 minutes after death allowing detection of the proportion of carcasses showing extreme PSE characteristics (early PSE) (Frøystein et al., 2003). Measurement with the probe at a later time (e.g. 20 to 24 hours post-mortem) reveals a much greater proportion of PSE carcasses. This makes the Hennessy probe a method for indirectly measuring the pH and WHC of the meat. Research has been conducted in developing an online optical fibre sensor probe that monitors various meat products online, as they cook, in order to determine the colour progress during cooking (O’Farrell et al., 2004) and also the quality, e.g. if premature browning has occurred in the case of ground beef (O’Farrell et al., 2007). The analysis of the spectra from these probes involves removal of intensity fluctuations by normalisation and a neural network is used to classify the colour based on the shape of the spectrum. This solution requires a robotic arm to move the probe across

Nealy perpendicular

Fig. 22.3 Correct Insertion of the Hennessy Grading Probe (www.hennessytechnology.com).

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

555

the surface of the belt as the food comes out of a conveyor belt oven. The probe included an optical fibre with a fibre Bragg grating for temperature measurements and could, therefore, be inserted in the product for combined internal temperature and colour information. Optical fibre probes have also been developed to monitor meat emulsion stability and breakdown (Barbut, 1998, 1999) and this has been investigated again recently (Álvarez et al., 2009). Finely comminuted products such as sausages, frankfurters and bolognas are among the products that are made from meat emulsions. By monitoring the colour during the chopping, the optimum end time can be predicted when making an emulsion with maximum stability during heat treatment. The changes at certain wavelengths between 565 and 696 nm in the VIS spectra were well correlated with the fat and water losses during meat emulsion treatment. Machine vision Machine vision is the engineering of integrated mechanical–optical– electronic–software systems and can be used for examining food products in order to detect defects and quality parameters, increase operating efficiency and the safety of both the products and processes. These systems incorporate high resolution cameras to acquire an image of the product. The quality of the analysis is dependent on the quality of the image. Image pre-processing refers to the initial processing of the raw image data for correction of geometric distortions, removal of noise, grey level correction and correction for blurring. The pixels of the image can then be represented by a colour code, e.g. the RGB colour coordinates or other colour models such as hue saturation value (HSV), hue light saturation (HLS), XYZ, etc. (Shevell, 2003). Food can be very difficult as a measurand as it is subject to variation. To help deal with this variation and classify characteristics in the image, interpretation of the data can be in the form of multilayer neural networks or statistical analysis. Measuring absolute colour using cameras is susceptible to the same problems that reflectance spectroscopy measurements are, i.e. surface unevenness, shadows, ambient light and stray light causing subtle shifts in apparent colour. It is difficult to produce the same values obtained with a colorimeter as with a camera system and there has, therefore, been more success using this technology to measure relative colour, as in the case of Marel Food Systems INS 2000 Vision Slicer. This system uses a high speed camera to capture an image of bacon to determine the fat/lean ratio using the colour difference between fat and meat and information on the density of fat and meat, in order to adjust the thickness of the next slice. Measuring relative colour is also very useful in measuring surface defects on products. Measuring the shape and size of products accurately is essential for online slicing and portioning. Laser triangulation is often employed in automatic slicers, where a laser line is projected across the surface of the

© Woodhead Publishing Limited, 2011

556

Processed meats

object, while a camera views the line at an angle and resolves its shape; any item moving through the laser line will cause a distortion in the shape of the reflected laser line. The Swedish company, Sick IVP, part of the global company Sick, which sells industrial sensors for factory automation, supplies machine vision systems for different applications within the food and beverage industries. Its 3D smart camera, the IVC–3D smart camera, processes images of the laser line at a rate of up to 5000 3D profiles per second for a normal conveyor speed. It can be used in automatically guiding portioning equipment, which calculates the virtual slices of the piece from the 3D image and sends the information to a control system that calculates the optimal cut position, before a knife makes the actual cutting with 3–5% accuracy per portion. Marel Food Systems incorporate a smart camera from Vision Components in their Intelligent Portioning Machine (IPM). This also uses laser triangulation line to map the shape of meat to work out the portions and positions at which to cut the slices. In a case study performed by Marel Food Systems on a plant processing 14 tons of boxed meat into steaks, the IPM III increased the yield by 2%. Pick-and-place applications employ machine vision technology to guide robotics to sort meat as it moves on a conveyor belt. This type of system is found at Unilever’s factory in Ansbacher, Germany. At the Bifi (salami snack) packing line, IRB 340 FlexPickers from ABB are installed, with a vision system provided by Cognex, to take six different sausage types from the conveyor belt to the packing machine. The robots continually pick the sausages and place them into rows of thermoformed cavities for vacuum packaging. By operating the packaging machine at maximum capacity, the performance was increased by 25% compared with manual loading. The IRB 240 FlexPicker is also being used by the Charkman Group at its meat packing operation in Boras, Sweden. The robot accurately loads sliced meat portions (10–24 slices) into preformed trays. Measurement of the quality of the packaging in terms of sealing and labelling is an application of machine vision that is well developed. This involves checking barcodes, expiration dates, code numbers, sealing (for bubbles and folds) and orientation. Examples of companies involved in packaging monitoring include the iLabel verification system, manufactured by Dalsa IPD, Massachusetts, USA and ThermoSecure, by LUCEO Food Inspection Technologies, Vern sur Seiche, FranceFuture trends and challenges. Multispectral and hyperspectral imaging The advantages of spectroscopy and machine vision continue to be exploited as separate entities but now multispectral imaging combines the imaging and belt coverage capabilities of machines vision with the more extensive wavelength-specific information that is possible with spectroscopy. Multispectral imaging is growing in popularity and cost effectiveness. For each

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

557

pixel in the image, a multispectral camera acquires the light intensity for several spectral bands ranging from ultraviolet (UV) to NIR. Every pixel in the image thus contains a continuous spectrum and selecting suitable wavelengths allows improved characterisation of the objects in the image. Multispectral data contains from tens to hundreds of bands, whereas hyperspectral data contains hundreds to thousands of bands. There are many institutes that are currently investigating the possibilities of multispectral or hyperspectral imaging in the meat processing industry, for example in the area of measuring intramuscular fat in pork (Qiao et al., 2007). In their research, images from meat standards were digitised and the extracted textural features from these were compared with the extracted textural features from hyperspectral images of 40 pork samples. When compared to subjective classification of the samples, there was an error of approximately 1 for a meat standard with 10 levels, which was attributed to halation in the images. In the poultry industry results have shown that using band ratios of images at 565 and 517 nm, faecal and ingesta matter could be discriminated from poultry carcasses with approximately 96.4% accuracy on a limited data set (Park et al., 2005). Later research by the same group further developed the algorithms to differentiate between three different fecal contaminants; duodenum, colon and ceca, with an accuracy of 90%, using 512 narrow bands from 400 to 900 nm (Park et al., 2007). These publications demonstrate the potential in this area but for it to be deployed as an online technique in the industry it must be made more flexible, e.g. simplified systems with application based wavelength design, faster and lower in cost. ImSpector from Specim Spectral Imaging Ltd., Finland and HySpex(TM) from Norsk Elektro Optikk AS, Norway, are examples of hyperspectral imaging systems. ImSpector is available for different ranges and resolutions depending on the application, for example ImpSector UV4E covers a range from 200 to 400 nm (resolution 2 nm), ImSpector V8E operates at 380– 800 nm (resolution 2 nm) and ImSpector V10 goes from 4 to 1 μm (resolution 11.2 nm). The VNIR–640 HySpex covers the region from 0.4 to 1 μm with spectral sampling every 5/10 nm and the VNIR-1600 covers the same spectral range with spectral sampling every 3.7 nm. Both ImSpector and HySpex systems have been investigated for food applications, especially in baking and fruit sorting and quality-monitoring applications. The ImSpector V9 has been investigated by Park et al. (2005, 2007) for faecal detection, as described above and the ImSpector V10E was used for measuring marbling in pork, also described above (Qiao et al., 2007). These systems are more expensive than multispectral imaging systems but offer many possibilities in the future as they combine high spatial resolution imaging with high spectral resolution spectra. JAI, a digital camera manufacturer based in Copenhagen, Denmark, produces a multispectral camera that simultaneously measures both VIS and NIR light through a single lens using two channels. The AD–080CL

© Woodhead Publishing Limited, 2011

558

Processed meats

camera is a relatively new camera (2008) at a competitive price that has been applied to sorting and grading fruit and vegetables, where the visible channel (RGB) is used for determining the ripeness of the fruit while images from the NIR channel (800 nm peak response) show any sort of bruising or tissue damage under the skin. QVision AS has had success in low-cost multispectral imaging that operates over a moving conveyor belt. Their product, QMonitor, creates images with 15 wavelength reflectance spectra in VIS region (430–730 nm) and 15 wavelength interactance spectra in NIR (740–1050 nm). Using both multispectral images a profile of pigment, water and fat content can be combined for meat and fish products.

22.4 Food safety 22.4.1 Background Food processors have a legal duty to make sure that the products served or sold to customers are safe to eat. Every food business will have different risks, depending on the type of food that is prepared and the way in which it is produced and handled. A written food safety management plan and procedures, based on hazard analysis and critical control points (HACCP) principles, must be in place, implemented and maintained. HACCP is an internationally recognised and recommended system for food safety management. It focuses on identifying the ‘critical points’ in a process where food safety problems (or ‘hazards’) could arise and putting steps in place to prevent things going wrong. In a typical meat processing plant the following precautions should be taken: • Minimise the likelihood of food poisoning bacteria contaminating meat and associated products. • Prevent physical and chemical contamination of meat. • Mitigate the likelihood food poisoning bacterial growth on meat and associated products. This section details online systems that help in taking these precautions in terms of temperature measurements, foreign object detection and contamination.

22.4.2 Online techniques IR imaging Fully cooked products represent a fast-growing segment of the prepared foods market. The challenge for processors is to ensure that products are fully cooked so that all bacteria are destroyed, without being overcooked to a point where yield and quality are impacted. It is standard to have one or more human inspectors to repeatedly insert temperature probes into the

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

559

product. Manual inspection is a full-time task that requires the inspector to identify the largest piece on the belt, insert a probe in the part that will take the longest to cook, and then wait for the probe to stabilise. Temperature measurements made by this process can easily vary by 6 °C on irregular products, so processors are forced to overcook, to ensure all pieces in a batch or group reach the required minimum core temperature. Temperature is also critical during chilling, holding, freezing, storage and other processes, such as meat emulsion preparation. IR imaging is applied in some processes for non-contact temperature measurements but it is restricted in terms of penetration depth; it only measures the surface temperature. Georgia Tech Research institute has done much research in the area of non-contact core temperature measurements by developing models based on the surface temperature (Stewart et al., 2006). A case study was conducted, where a Mikron 7302 microbolometer camera (8–14 μm) was placed at the exit of an oven at Gold Kist, Boaz, AL. This installation was investigated over one year with changeover between chicken nuggets and chicken patties. Calibrations were performed at three and six months to check the stability of the system and there was no significant drift over the period. The pieces were found on the belt using segmentation routines and the core temperature was estimated based on surface and height information. The predicted temperature based on the camera for a single day with changeover from nuggets to patties at hour 17 is shown in Fig. 22.4. Flir Systems is also investigating the development of IR imaging technology that is specifically for food safety inspection to check that foods are stored at the correct temperature. The Flir ThermaCAM is used for inspecting the electrical and mechanical equipment found in food retail,

Product temperature (°F)

240 230 220 210 200 190 180 170 8

9

10

11

12

13

14

15 16 17 Hour of day

18

19

20

21

22

23

Fig. 22.4 Temperature calculated with Mikron 7302. The black dotted trace is the surface temperature, the bars are quality control thermocouples and the solid black trace is the mean temperature over each minute as calculated by the IR camera (Stewart et al. 2006).

© Woodhead Publishing Limited, 2011

560

Processed meats

warehousing and production facilities. By monitoring power loss in food storage and production areas, potential increases in storage temperatures can be avoided. Despite the potential of thermal imaging in terms of belt coverage and automation possibilities, it is still not widely applied in the food industry and process lines continue to employ technicians to perform the task. X-rays There are two main reasons for detecting foreign objects in the process line: • The detection of objects that can cause serious injury to the customer. This of course is a safety issue first and foremost, but also serves to protect the brand of the meat processor. • Protection of equipment against foreign objects that can damage machinery on the process line, causing significant downtime in the process. The contaminants in the meat processing industry can be metallic or nonmetallic and can come from numerous sources. An example HACCP plan for incoming materials used in sausage making is given in Table 22.1. Metal detectors are well-established and cost-effective instruments for detecting metal contamination. However, items such as stones, glass, ceramics, bones, plastics are potential contaminants that are not detectable using this method. It is for this reason that X-ray systems are now more widely used. Smiths Detection (Eagle Bulk 370 X-ray) and Ishida Europe both provide inspection equipment for foreign object detection in the meat industry. An Ishida IX–GA–2475 X-ray machine is installed in Rose Poultry, Denmark, which is a large manufacturer of chicken products. The X-ray system is capable of detecting small pieces of bone, at speeds of up to 160 fillets per minute. Hamamatsu has also developed X-ray detectors that detect contaminants in canned and packed food and recent developments in sensor technology means that the systems can work at higher speed and resolution. Where dual energy X-ray allows dividing the X-ray spectrum into two

Table 22.1

Example of HACCP plan for sausage making

Metallic

Non-metallic

From the animal – broken needles, shot gun pellets, knife chips From salt and spices – metal chips from grinding and mixing equipment From purchased ice – nails and metal chips

From the animal – bone particles From added salt – metal, wood or plastic particles, gravel From spices – hard pieces of stem or gravel From purchased ice – wood chips, gravel, etc.

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

561

levels, using two different sources, Hamamatsu has developed a line sensor, C10413 (October, 2006), that allows five energy levels to be differentiated by using a cadmium telluride (CdTe) detector and dividing the detected photons (light particles) based on their energy levels, using comparators. The photons are counted and the total energy for each of the five bands is summed. This allows the simultaneous measurement of images at five different energy levels (similar to the concept behind multispectral imaging) allowing greater differentiation and contrast in the images. Fluorescence Fluorescence is a form of luminescence in which the molecular absorption of a photon triggers the emission of a photon at a longer (less energetic) wavelength. Sometimes the absorbed photon is in the UV range, and the emitted light is in the VIS range and it is this type of fluorescence is used in the area of faecal detection (both visible and invisible to the eye). VerifEYETM Technology is the manufacturer of equipment based on fluorescence spectroscopy and image processing. The Food Standards Agency (Food Standards Agency, n.d.), an independent government department in the United Kingdom, funded a study where rapid methods were investigated and compared for measuring contamination (UKMeat.org, n.d.). The methods tested were fluorescence-based, VerifEYE Solo, and traditional offline microbiological test kits; Pro–tect (Biotrace International Plc.) and Flash stick detection (Biocontrol), both of which detect the concentration of protein residue. The results of the study indicated that the VerifEYE Solo (the handheld version) was a good method to measure overall contamination for cattle and sheep carcasses; however, it was not suitable for assessing pig carcasses or the cleanliness of environmental surfaces, where Pro–tect and Flash stick detection proved superior.

22.4.3 Future trends Advances in foreign object detection There is a continuing problem in the food industry regarding the detection of lower density items such as plastics or distinguishing between items of similar density, such as glass and nuts, where conventional X-ray systems suffer from the low dielectric contrast between the food product and contaminant. This challenge is being investigated by research groups that are working in the relatively new area of terahertz spectroscopy. Terahertz radiation has the capability of penetrating a wide variety of non-conducting materials. Besides having better dielectric contrast, terahertz is also nonionising but it has lower spatial resolution due to its longer wavelength. Terahertz occupies what has been known as the ‘terahertz gap’, the separation between optics and electronics in the electromagnetic spectrum, between IR and microwave. A successful investigation has been made in distinguishing between nuts and glass in chocolate using Terahertz (Jördens

© Woodhead Publishing Limited, 2011

562

Processed meats

et al., 2006), which would be very difficult, if not impossible, for X-ray-based technologies. For now, terahertz components and systems are slow and expensive; however, progress in this area could lead to the development of even more advanced foreign object detection, including the possibility of detecting low density objects such as plastic in food. Non-destructive testing of different polymeric compounds with Terahertz time-domain spectroscopy is discussed in greater detail by Wietzke et al. (2007). Food freshness Fluorescence, which has been employed to measure contamination in the meat industry, can also be used to measure lipid oxidation, one of the first indicators of food spoilage. However, fast online techniques are not yet available for the industry. Currently available techniques are time–consuming, such as sensory panels and thiobarbituric acid reactive substances (TBARS numbers). Research in the area of fluorescence for detecting lipid oxidation has been successfully achieved using laboratory-based equipment (Wold and Kval, 2000; Veberg et al., 2006; Airado-Rodriguez et al., 2010), but development of low cost techniques is necessary to bring this technique online. Another group has recently investigated using fluorescence (excitation 420 nm) to monitor the ageing process of pork meat by detecting increases in zinc protoporphyrin IX (ZnPP), which proved better than using pH and colour (Schneider et al., 2008). The authors concluded that the next stage of the research would be developing a commercial handheld optical detector, based on these results, for determining freshness.

22.5 Automation and integration of the quality measurements Robotics, initially developed for the automotive industry, is now inherent in the food industry. Advances in robotics, intelligent algorithms and machine vision technology have enabled automations for selecting, sorting, ‘pick and place’ and packaging. The inclusion of robotics in the meat processing industry requires intelligence based on quality measurements made throughout the process. There are several companies working in these areas, with many applications in the meat industry, including Marel Food Sytems, ABB Robotics, Gerhard Schubert GmbH., Sigpack Systems AG, ATTEK Danmark AS, Robot Grader AB and LMI Technologies. Machine vision as mentioned above, plays a large part in the use of robots in the food industry. Predictions made by the Automated Imaging Association (AIA) (2009) state that vision guided robotics will play an increasing role in the food industry. This, however, is limited by the challenges of machine vision; integration, synchronisation and component interoperation. This means that standardisation continues to be a problem even

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

563

though the strengths of machine vision are clear and the cost of components themselves is reducing. This problem is in fact, not solely limited to machine vision-based quality measurements. In fact, all of the quality measurement systems described above face the same problem; generation of data is one thing, utilisation of the data is quite another. It is not sufficient making online measurement of the composition of meat trimmings, for example, if it is not incorporated in to the logistics of the process line; cutting method selection, recipe optimisation, etc. Simplifying this integration and collaboration between suppliers of various technologies, meat processors, research institutes and academia is essential for progress to be made in developing new technologies and to enable incorporation of these new technologies in to existing lines.

22.6 Sources of further information and advice Keeping abreast of new technologies and trends requires getting information from a combination of sources. Of course, it is necessary to monitor developments in academia by subscribing to journals such as Applied Spectroscopy (Society for Applied Spectroscopy), Journal of Meat Science (American Meat Science Association), Measurement Science Technology (Institute of Physics), Journal of Infrared Spectroscopy (IM Publications) and Journal of Food Science (Institute of Food Technologists). However, it can also be very useful to use magazines or web pages to find out the latest news in technology and application developments in the meat industry. Websites for the following are provided in the references: MeatProcess.com, MeatInfo.co.uk, AP-FoodTechnology.com, Food Quality News, American Meat Science Association, Processing Talk, Image and Machine Vision Europe, Machine Vision Online, Vision Systems Design, Spectroscopy News, Spectroscopy NOW. For details on regulations, news, funding, factsheets and events, take advantage of the information available on governmental websites (Food Safety and Inspection Service, Food Standards Agency, Food Safety Authority Ireland).

22.7 References airado-rodriguez d, skarett j, wold j p, ‘Assessment of the quality attributes of cod caviar paste by means of front-face fluorescence spectroscopy’ Agricultural Food Chemistry, 2010, 58(9), 5276–5285 albuquerque m l s, guedes i, alcantara jr p, moreira s g c, ‘Infrared absorption spectra of Buriti (Mauritia flexuosa L.) oil’, Journal of Vibrational Spectroscopy, 2003, 33(1–2), 127–131 álvarez d, castillo m, payne f a, xiong y l, ‘A novel fiber optic sensor to monitor beef meat emulsion stability using visible light scattering’, Meat Science, 2009, 81(3), 456–466

© Woodhead Publishing Limited, 2011

564

Processed meats

american meat science association. Available from: www.meatscience.org [accessed 16 July 2010] ap-foodtechnology.com, decision news media sas. Available from: www. ap-foodtechnology.com [accessed 16 July 2010] automated imaging association (2009), ‘The 2009 Machine Vision Markets Study Machine Vision Markets: 2008 Results and Forecasts to 2013’. Available from: http://www.machinevisiononline.org/market-data.cfm?id=150 [accessed 16 July 2010] barbut s, ‘Use of fiber optic probe to predict meat emulsion breakdown’, Italian Journal of Food Science, 1998, 3, 253–259 barbut s, ‘Advances in determining meat emulsion stability’ in Xiong et al., Editors, Quality Attributes of Muscle Foods, New York, Kluwer Academic/Plenum Publishers, 1999 barbut s, ‘Acceptance of fresh chicken meat presented under three light sources’, Poultry Science, 2001a, 80, 101–104 barbut s, ‘Effect of illumination source on the appearance of fresh meat cuts’, Meat Science, 2001b, 59, 187–191 begley t h, lanza e, norris k h, hruschka w r, ‘Determination of sodium chloride in meat by near-infrared diffuse reflectance spectroscopy’, Journal of Agricultural and Food Chemistry, 1984, 32, 984–987 brienne j p, denoyelle c, baussart h, daudin j d, ‘Assessment of meat fat content using dual energy X-ray absorption’, Meat Science, 2001, 57, 235–244 clydesdale f m, gover r, philipsen d h, fugardi c, ‘The effect of color on thirst quenching, sweetness, acceptability and flavour intensity in fruit flavoured beverages’, Journal of Food Quality, 1992, 15, 19–38 folkestad a, wold j p, rørvik k a, tschudi j, haugholt k h, kolstad k, mørkøre t, ‘Rapid and non-invasive measurements of fat and pigment concentrations in live and slaughtered Atlantic salmon (Salmo salar L.)’, Aquaculture, 2008, 280, 129–135 food quality news, decision news media sas. Available from: www.foodqualitynews.com [accessed 16 July 2010] food safety and inspection service, united states. Available from: www.fsis.usda. gov [accessed 28 July 2009] food safety authority of ireland, ireland. Available from: www.fsai.ie [accessed 16 July 2010] food standards agency, united kingdom. Available from www.food.gov.uk [accessed 16 July 2010] frøystein t, røe m, alvseike o, wahlgren m, granhaug m, ‘Effects of new systems for preslaughter handling and CO2-stunning of pigs on meat quality assessed by the Hennessy grading probe (GP2Q)’, Proceedings of the 49th ICoMST, 2nd. Brazilian Congress of Meat Science and Technology, Campinas, Brazil, August 2003 hansen p w, tholl i, christensen c, jehg h, borg j, nielsen o, østergaard b, nygaard j, andersen o, ‘Batch accuracy of on-line fat determination’, Meat Science, 2003, 64(2), 141–147 herrero a m, ‘Raman spectroscopy a promising technique for quality assessment of meat and fish: a review’, Journal of Food Chemistry, 2008, 15, 1642–1651 honikel k o, ‘The use and control of nitrate and nitrite for the processing of meat products,’ Meat Science, 2008, 78(1–2), 68–76 hunt r w g, Measuring Colour, 2nd edition, Ellis Horwood Limited, 1991 hunterlab associates inc. ‘Evaluation of appearance,’ Applications Note, 2008, 12(6), 1–5 image and machine vision europe, europa science ltd, available from: www. imveurope.com [accessed 16 July 2010]

© Woodhead Publishing Limited, 2011

Online quality assessment of processed meats

565

jördens c, rutz f, koch m, ‘Quality Assurance of Chocolate Products with Terahertz Imaging’, Proc. European Federation for Non-Destructive Testing, 2006, Berlin lin m, cavinato a g, huang y, rasco b a, ‘Predicting sodium chloride content in commercial king (Oncorhynchus tshawytscha) and chum (O. keta) hot smoked salmon fillet portions by short-wavelength near-infrared (SW-NIR) spectroscopy’, Food Research International, 2003, 36, 761–766 machine vision online, automated imaging association (aia). Available from www. machinevisiononline.org [accessed 16 July 2010] meatinfo.co.uk, meat trades journal. Available from www.meatinfo.co.uk [accessed 16 July 2010] meatprocess.com, decision news media sas. Available from: www.meatprocess.com [accessed 16 July 2010] mignani a g, ciaccheri l, cucci c, d’iaz-herrera n, mencaglia a a, ottevaere h, attilio c, ottevaere h, thienpont h, paolesse r, mastroianni m, monti d, gerevini m, buonocore g, del nobile m a, mentana a, grimaldi m f, dall’asta c, faccini a, galaverna g, dossena a, ‘EAT-by-LIGHT: Fiber-Optic and Micro-Optic Devices for Food Quality and Safety Assessment’ Sensors Journal, IEEE, 2008, 8(7), 1342–1354 moller j k s, jakobsen m, weber c j, martinussen t, skibsted l h, bertelsen g, ‘Optimisation of colour stability of cured ham during packaging and retail display by a multifactorial design’, Meat Science, 2003, 63, 169–175 o’farrell m, lewis e, flanagan c, lyons w, jackman n, ‘Using a reflection based optical fibre system and neural networks to evaluate the quality of food in a large-scale industrial oven’, Sensors & Actuators: A. Physical, 2004, 115, 424–433 o’farrell m, sheridan c, lewis e, flanagan c, kerry j f, jackman n, ‘Online optical fibre sensor for detecting premature browning in ground beef using pattern recognition & reflection spectroscopy’, IEEE Sensors, 2007, 7(12), 1685–1692 o’farrell m, wold j p, høy m, tschudi j., schulerud h, ‘On-line fat content classification of inhomogeneous pork trimmings using multispectral near infrared interactance imaging’, Near Infrared Spectroscopy, 2010, 18(2), 135–146 ottestad s, høy m, stevik a, wold j p, ‘Prediction of ice fraction and fat content in superchilled salmon by non-contact interactance near infrared imaging’, Journal of Near Infrared Spectroscopy, 2009, 17(2), 77–87 park b, lawrence k c, windham w r, smith d, ‘Performance of hyperspectral imaging system for poultry surface fecal contaminant detection’, Journal of Food Engineering, 2005, 75(3), 340–348 park b, windham w r, lawrence k c, smith d, ‘Contaminant classification of poultry hyperspectral imagery using a spectral angle mapper algorithm’, Biosystems Engineering, 2007, 96(3), 323–333 processing talk, pro-talk ltd. Available from: www.processingtalk.com [accessed 16 July 2010] qiao j, ngadi m, wang n, gariépy c, prasher s, ‘Pork quality and marbling level assessment using a hyperspectral imaging system’, Journal of Food Engineering, 2007, 83(1), 10–16 schmidt h, sowoidnich k, maiwald m, sump b, kronfeldt h d, ‘Hand-held Raman sensor head for in-situ characterization of meat quality applying a microsystem 671 nm diode laser’, Proceedings of the SPIE, 2009, 7315, 731509–731509–8 schneider j, wulf j, surowsky b, schmidt h, schwägele f, schlüter o, ‘Fluorimetric detection of protoporphyrins as an indicator for quality monitoring of fresh intact pork meat’, Journal of Meat Science, 2008, 80(4), 1320–1325 sebranek j g, bacus j b, ‘Cured meat products without direct addition of nitrate or nitrite: what are the issues?’, Meat Science, 2007, 77(1), 136–147 shevell s k, The Science of Color, 2nd edition, Elsevier Science, 2003

© Woodhead Publishing Limited, 2011

566

Processed meats

spectroscopy news, selectscience 2009. Available from: www.spectroscopynews. net [accessed 16 July 2010] spectroscopy now, john wiley & sons, ltd. Available from: www.spectroscopynow. com [accessed 16 July 2010] stewart j, matthews m, glasco m, ‘Final cook temperature monitoring’, Proceedings of the International Society for Optical Engineering ThermoSense XXVIII Conference. April 17–20 2006, Orlando, FL, 6205 togersen g, isaksson t, nilsen b n, bakker e a, hildrum k i, ‘On-line NIR analysis of fat, water and protein in industrial scale ground meat batches’, Meat Science, 1999, 51(1), 97–102 ukmeat.org, hutchison scientific ltd. Available from: http://www.ukmeat.org/Surfaces.htm [accessed 16 July 2010] veberg a, olsen e, vogt g, mielnik m, nilsen a n, wold j p, ‘Front face fluorescence spectroscopy, a rapid method to detect early lipid oxidation in freeze stored minced turkey meat’, Journal of Food Science, 2006, 71(4), S364–S370 vision systems design, pennwell’s optoelectronics & communications group. Available from: www.vision-systems.com [accessed 16 July 2010] wietzke s, jansen c, rutz f, mittleman d m, koch m, ‘Determination of additive content in polymeric compounds with terahertz time-domain spectroscopy’, Polymer Testing, 2007, 26(5), 614–618 wold j p, kvaal k, ‘Mapping lipid oxidation in chicken meat by multispectral imaging of autofluorescence’, Applied Spectroscopy, 2000, 54(6), 900–909 wood j d, enser m, fisher a v, nute g r, sheard p r, richardson r i, hughes s i, whittington f m, ‘Fat deposition, fatty acid composition and meat quality: a review’, Meat Science, 2007, 78(4), 343–358

© Woodhead Publishing Limited, 2011

23 Impact of refrigeration on processed meat safety and quality S. J. James and C. James, Food Refrigeration & Process Engineering Research Centre (FRPERC), UK

Abstract: This chapter looks at the impact of all of the different operations of the food cold chain on the safety and quality of processed meats. The complete cold chain for processed meats contains a number of temperature reduction processes (i.e. chilling, freezing, crust freezing, tempering), together with other processes where no change in average meat temperature is required (i.e. chilled and frozen storage, transport, retail display and domestic storage). How these operations impact on product quality and safety is discussed in detail, together with how these operations can be optimised to improve quality and safety. Key words: processed meat, cold-chain, chilling, freezing, crust freezing, tempering, chilled storage, frozen storage, transport, retail display, domestic storage.

23.1 Introduction The prime purpose of refrigerating processed meats is to reduce the temperature of the meat to a value below which the rate of bacterial growth is either severely slowed (chilling) or stopped (freezing). The complete cold chain for processed meats contains a number of temperature reduction processes (i.e. chilling, freezing, crust freezing, tempering), together with other processes where no change in average meat temperature is required (i.e. chilled and frozen storage, transport, retail display and domestic storage). It also contains processes such as cooking, thawing and tempering where a controlled temperature rise is planned, and others such as slicing, mincing, packing, etc. that can result in an uncontrolled temperature rise. There are only four basic mechanisms (conduction, radiation, convection and evaporation/condensation) that can be used to change the temperature of meat. Conduction requires a good physical contact between the meat to be cooled and the cooling medium and this is difficult to achieve with

© Woodhead Publishing Limited, 2011

568

Processed meats

irregular meat cuts. Contact chilling and freezing methods are based on heat transfer by contact between products and metal surfaces (which in turn are cooled by either primary or secondary refrigerants). The most common of these are plate systems, employed for blocks of products. Radiation does not require any physical contact but a large temperature difference is required between the surface of the meat being cooled and that of surrounding surfaces to achieve significant heat flow. In the initial stages of the chilling of cooked processed meats radiant heat loss can be substantial if the products are surrounded by cold surfaces. Evaporation from a meat surface reduces yield and is not desirable in most processed meat refrigeration operations. In evaporative (spray) chilling systems for wrapped meat joints, hams, cooked sausages etc. water showers are applied at intervals to the surface of product (Fig. 23.1). The principle of the process is to increase the rate of evaporative heat loss, and in some cases reduce the overall weight loss by replacing the water lost. The intervals are required to allow evaporation, not, as stated in Feiner (2006), because continuous spraying ‘traps the heat in the product’. Vacuum cooling also relies on evaporative heat transfer (Burfoot et al., 1990). There is little published information on the hygienic design of food refrigeration systems. Since the outer surface of a cooked product should be pasteurised at the end of cooking, provided potable water is used during spray cooling there should be no contamination or cross-contamination problems. Cross-contamination has been considered to be one of the major problems with immersion chilling; however, a study by Mead et al. (2000) provides evidence that microbial cross-contamination can also occur during air chilling of poultry, whether or not water sprays are incorporated in the chilling process. Studies have found substantial (>105 cm−2) numbers of bacteria on the evaporator coils in chill rooms in food production factories (Evans et al., 2004). Further investigations carried out in the laboratory

Fig. 23.1 Spray/evaporative cooling of saveloy sausages.

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

569

showed that bacteria would not grow on clean coils under the conditions recorded in industrial plants. Designing coils that were easy to clean and establishing routine cleaning schedules would therefore reduce any contamination risks in food refrigeration systems. Convection is by far the most important heat transfer mechanism employed in processed meat refrigeration systems. In most cases refrigerated air is the transfer medium, as it is economical, hygienic and relatively non-corrosive to equipment. However, in some cases immersion systems can be used. An immersion chiller or freezer is made up of a tank with a cooled liquid that can be any non-toxic salt, sugar or alcohol solution in water and a means of conveying the wrapped meat through the tank. Ice slurries are increasingly being considered as an alternative to conventional immersion liquids. Such binary systems are described in the scientific literature as flow ice, fluid ice, slush ice or liquid ice. Such systems are reported to achieve higher rates of heat transfer than the single state liquids (Maria et al., 2005). Cryogenic chilling, or freezing, is essentially a subset of immersion cooling, in that it uses cryogenic refrigerants, such as liquid nitrogen or solid carbon dioxide, directly. Cooling is brought about by boiling off the refrigerant. As well as using the latent heat absorbed by the boiling liquid, sensible heat is absorbed by the resulting cold gas. Owing to very low operating temperatures and high surface heat transfer coefficients between product and medium, cooling rates of cryogenic systems are often substantially higher than other refrigeration systems. However, surface freezing can be a problem in using cryogens to chill rather than freeze. In an air-based system, the air temperature, air velocity and, to a limited extent, relative humidity are the environmental factors that affect the cooling time of the meat. Cooling rate will also be a function of the thickness and fat cover of the cooked product. Systems range from the most basic in which a fan draws air through a refrigerated coil and blows the cooled air around an insulated room, to purpose-built conveyerised blast freezing tunnels or spirals. Relatively low rates of heat transfer are attained from product surfaces in air systems. The big advantage of air systems is their versatility; especially when there is a requirement to chill or freeze a variety of irregularly shaped products. In a continuous system processed meats are conveyed through a tunnel or refrigerated room, usually by an overhead conveyor or on a belt. This overcomes the problem of uneven air distribution since each item is subjected to the same velocity/time profile. Some processed meats are chilled or frozen on racks of trays (2 m high), pulled or pushed through a tunnel by mechanical means. For larger operations, it is more satisfactory to feed meats on a continuous belt through linear tunnels or spiral coolers. The rate at which heat can be extracted from a food is a function of the surface heat transfer coefficient. The surface heat transfer is a characteristic of the refrigeration system used and how the cooling medium produced,

© Woodhead Publishing Limited, 2011

570

Processed meats

Table 23.1 Typical surface heat transfer coefficients, h, for different refrigeration systems Surface heat transfer coefficient, h (W m−2 K−1)

Refrigeration systems

8–12 16–25 30–40 50–70 100 200 500 400–500 1000–1500

Air, low velocity (0.1 to 0.5 m s−1) Air, medium low velocity (1 to 2 m s−1) Air, medium velocity (3 m s−1) Air, high velocity (6 m s−1) Immersion, no flow Immersion, low flow Immersion, high flow Plate, direct contact Cryogenic, direct immersion

Table 23.2 Lowest operating temperatures of different refrigeration systems Lowest operating temperatures (°C)

Refrigeration systems

−35 to −40

Conventional mechanical refrigeration systems (air, immersion) Solid carbon dioxide Air cycle Liquid nitrogen

−78 −100 −196

interacts with the product being refrigerated. Typical surface heat transfer coefficients for different refrigeration systems are shown in Table 23.1. The lowest operating temperature available is also a characteristic of different refrigeration systems. Air, immersion and plate refrigeration systems typically use conventional mechanical refrigeration cycles to cool the refrigeration, thus unless a cryogen or air cycle is used to cool, these systems are all restricted to similar operating temperatures (Table 23.2). In a chilling system for processed meats the lowest temperature used is often restricted by the requirement to avoid surface freezing. With many processed meats the time required to chill or freeze the product is governed by the rate at which heat is conducted from the centre of the food to the surface rather than the surface heat transfer coefficient.

23.2 Current understanding of the impact of refrigeration on processed meat safety and quality In general, the storage life of chilled processed meats are restricted by the growth of spoilage microorganisms, while the storage life of frozen

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

571

processed meats is principally restricted by rancidity development in fats (lipids). During the retail display of unwrapped processed meats unacceptable surface dehydration changes often occur before spoilage has developed.

23.2.1 Impact of chilling on processed meat safety The main pathogens of particular concern to human health that may be present in processed meats are Campylobacter spp., Clostridium perfringens, Clostridium botulinum, pathogenic serotypes of Escherichia coli, Listeria monocytogenes, Salmonellaenterica serovars, Yersinia enterocolitica and, to a lesser extent, Staphylococcus aureus and Bacillus cereus. Many processed meats are cooked during processing and are considered ‘ready to eat’. The aim of the cooking process in a cook–chill system is to ensure the destruction of vegetative stages of any pathogenic microorganisms present. The minimum recommended cooking temperature requirements will depend on the most thermally resistant pathogen that may present a risk in such products. For some processed meats this is L. monocytogenes or Salmonella Typhimurium, and a minimum temperature of 70 °C for not less than 2 minutes in the centre of the food, or the equivalent is recommended (Gaze et al., 1989). For other products non-proteolytic C. botulinum or C. perfringens are of most concern. These products require a more severe heat treatment of 90 °C for not less than 10 minutes, or the equivalent (European Chilled Food Federation, 1996). There is always the possibility that some microorganisms that produce spores will not be killed by the cooking process. Therefore the temperature of the product should be rapidly reduced between 60 and 7 °C to prevent multiplication. Further reduction to 3 °C is required to reduce the growth of spoilage bacteria. In addition to microbiological factors, rapid reduction in product temperature aids retention of nutrients (UK Department of Health, 1989), which is vital in a system often used for the preparation of meals for old, infirm and young people. EC Regulation 852/2004 (EC, 2004) contains a requirement for the cooling of cooked foodstuffs. Annex II, Chapter IX, 6 states ‘Where foodstuffs are to be held or served at chilled temperatures they are to be cooled as quickly as possible following the heat-processing stage, or final preparation stage if no heat process is applied, to a temperature which does not result in a risk to health’. This is similar to earlier legislation. More specific guidelines were produced for cook–chill products in the UK by the Department of Health (UK, Department of Health, 1989). These Guidelines state that the chilling process should commence as soon as possible after completion of cooking and certainly within 30 minutes of leaving the cooking process (this allows for portioning of meals). Small portions of food (less than 50 mm deep) should be chilled to between 0 and 3 °C within 90 minutes and large portion of food to 10 °C within 2.5 h after removal from the

© Woodhead Publishing Limited, 2011

572

Processed meats

Table 23.3 International chilling time guidelines/recommendations for the cooling of cooked foods Chilling Storage rate temperature (°C/minute) (°C)

Chilling range (°C)

Time (h)

60 to 21 21 to 5 60 to 20 20 to 4 60 to 10

≥2 ≥4 ≥2 ≥4 ≥2

0.33 0.07 0.33 0.07

Denmark

65 to 10

≥3

0.31

<5

France

70 to 10

≥2

0.50

0–3

Germany

≥2 ≥24 ≥2.5 ≥5 ≥24 ≥4

0.54

2

Ireland The Netherlands Sweden

80 to 15 (15 to 2) 70 to 3 60 to 7 7 to 4 80 to 8

0.45 0.18

3

0.30

3

UK

70 to 3

≥1.5

0.74

3

USA

60 to 5

4 to 6

Country Australia Canada Codex Alimentarius

5

Reference de Jong et al. (2004) CFISIG (2004)

4 Codex Alimentarius Commission (1999) Evans et al. (1996) Evans et al. (1996) Evans et al. (1996) FSAI (2004) de Jong et al. (2004) Evans et al. (1996) UK Department of Health (1989) de Jong et al. (2004)

cooking process. Many other countries have similar guidelines or recommendations for the cooling of cooked products (Table 23.3). Although the UK guidelines were produced specifically for cook–chill catering operations, owing to the lack of specific guidelines regarding the cooling of cooked foods for retail, they are widely used in the UK by the producers of chilled ready meals for retail sale. The Meat Products (Hygiene) Regulations (1994) contains special conditions for meat-based prepared meals. It requires that the meat product and the prepared meal shall be refrigerated to an internal temperature of +10 °C or less within a period of not more than 2 hours after the end of cooking. However, it then goes on to state that produce may be exempt from the 2 hour period where a longer period is justified for reasons connected with the production technology employed. The wording is similar in the EC Meat Products Directive.

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

573

In the USA the essential rules of the US Regulations (318.17 9 CFR CH III, 1.1.96 edition) on safe cooling of cooked meats are that: (1) chilling shall begin within 90 minutes after the cooling cycle is completed; (2) all products should be chilled from 48.8 to 12.7 °C in no more than 6 hours; (3) chilling shall continue and the product should not be packed for shipment until it has reached 4.4 °C. These US Federal Regulations have been widely adopted outside areas under the control of the USDA, including European retailers. Gaze et al. (1998) has made further recommendations for uncured and cured (defined as minimum 2.5% salt on water phase and 100 ppm nitrite in-going) meats (Table 23.4). James (1990a) describes in detail the methods available to cool meat joints and other cooked meat products while a review of the use of vacuum cooling in the food industry has been published by McDonald & Sun (2000). Surveys (Cook, 1985; James, 1990b,c; Gaze et al., 1998) have shown that industry uses a variety of methods for cooling whole hams and joints of meat. In these processes the earlier data showed that cooling times were as long as 21 hours, and final temperatures high, 15–20 °C (Cook, 1985; James, 1990b,c). In the later study cooling times were still as long as 16 hours but final temperatures were all below 8 °C (Gaze et al., 1998). The most relevant cooling data for cooling of cooked meat from laboratory investigations are shown in Table 23.4 and a simple process for estimating the immersion cooling time of beef roasts has been produced by Nolan (1986). Generally, the results show that immersion cooling is almost twice as fast as air cooling at the same temperature. Vacuum cooling is an order of magnitude faster than immersion cooling but weight loss is substantially (over twice) higher. Some processed meats are chilled using cryogenic tunnels; however, care must be taken to avoid surface freezing. Imperviously packed products can be chilled by immersion in cooled water or other suitable liquid. With some cooked products such as large hams in moulds and sausages, chlorinated water sprays may be used in the initial stages of cooling. Increasingly products such as pie fillings are pressure-cooked and vacuum cooled. With many products an initial cooling stage using ambient air can often substantially reduce the cooling load in the cooling system. The James and Bailey (1982) study showed that in ham cooling, a 0.75 hour initial cooling period in ambient air reduced the initial load on the refrigeration by a factor of almost 2. If the ham was placed straight into air at −2 °C it released 220 W h in the first hour compared with 118 W h after 0.75 minutes in ambient. In this case a period of ambient cooling would substantially reduce the peak heat load on the refrigeration system. With unwrapped processed meats much of the surface water can be removed during an ambient cooling stage thus reducing ice formation on cooling coils and the need for defrosts during production. Currently ambient cooling is not common practice due to beliefs that the air will spread contamination to the surface of the product and the slower initial cooling rate

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

James & Bailey (1982) Anon (1987)

McDonald & Sun (2000)

Gaze et al. (1998)

Reference

Recommended times Good practice (uncured meat) Maximum (uncured meat) Good practice (cured meat) Maximum (cured meat) 3.75 kg vacuum packed beef roasts 330 × 160 × 130 mm Vacuum Immersion 1 ± 1 °C Air 1 ± 1 °C, 2 ms−1 Air 1 ± 1 °C, 1 ms−1 7 kg hams in metal moulds Air −2 °C, 5 ms−1 0.75 h at 15 °C then −2 °C, 5 ms−1 5 to 5.5 kg (11 to 12 lb) ham logs 400 × 120 × 120 mm in metal moulds 30 m water spray at 18 °C then air 0 °C, 3 ms−1 top rack 30 m water spray at 18 °C then air 0 °C, 3 ms−1 bottom rack

Cooling regime

3.8 4.0 4.0 3.9

0.6 0.4

1.4 4.2 3.5 4.2

6 6 7.5 7.5

2.4 3.0

0.1 1.5 1.2 1.5

1 2.5 1.25 3.25

70 to 50 °C 50 to 12 °C

2.1 2.2

2.6 2.9

0.9 2.8 2.9 4.6

1 1.5 1.25 1.75

12 to 5 °C

6.7 6.5

9.0 9.9

2.4 8.5 7.6 10.3

8 10 10 12.5

70 to 5 °C

Cooling time (hours)

6.0 5.5

7.2 7.9

2.1 6.9 6.1 8.1

70 to 8 °C

Table 23.4 Comparison of recommended good practice and maximum cooling times for uncured and cured cooked meat with measured cooling times from published sources

© Woodhead Publishing Limited, 2011

Burfoot et al. (1990)

Burfoot et al. (1990)

Burfoot et al. (1990)

Burfoot et al. (1990)

Burfoot et al. (1990)

0.94 kg beef slabs, 50 mm thick Air 0 °C, 1.2 ms−1 Water 0 °C Vacuum 2.7 kg rolled beef forequarter, 110 mm diameter Air 0 °C, 1.2 ms−1 Water 0 °C Vacuum 2.7 kg rolled beef silverside, 110 mm diameter Air 0 °C, 1.2 ms−1 Water 0 °C Vacuum 6.4 kg boned out turkey Air 0 °C, 1.2 ms−1 Water 0 °C Vacuum 7.1 kg boned out ham Air 0 °C, 1.2 ms−1 Water 0 °C Vacuum 8.9 4.8 0.5

5.4 4.6 0.2

4.0 2.6 0.6

4.4 3.1 0.3

50 to 10 °C 1.7 1.0 0.6

10.4 5.9 0.5

6.6 5.6 0.3

4.9 3.1 0.7

5.1 3.6 0.4

70 to 10 °C 2.1 1.2 0.6

576

Processed meats

will result in increased bacterial growth. There is no scientific support for either belief. 23.2.2 Impact of chilled storage and display on processed meat safety Even air-dried processed meats that are produced to be relatively ambient stable, such as Parma ham, Black Forest ham, etc., are initially salted under refrigerated conditions, below 5 °C, for a number of weeks, before being dried in air at 12–15 °C for months (Feiner, 2006). Salmonella serovars are considered of greatest risk in spreadable raw fermented sausages (Feiner, 2006), such as Teewurst and Mettwurst. In addition to storage at low temperatures, salt levels around 2.5%, the presence of nitrite, and pH levels below 5.5 will aid the inhibition of salmonella. Cold-tolerant strains of C. botulinum types E and B can present a problem in improperly salted meats, where the water activity may be above 0.95, that are exposed to temperatures above 5 °C (Feiner, 2006). The growth of Salmonella serovars are prevented by temperatures below 7 °C, while L. monocytogenes is capable of multiplication at temperatures as low as 1 °C, unless the pH is below ca 5.0. The safest temperature for storage and display is essentially as low as possible. Thus, in terms of chilled meats that means a temperature as close as possible to the freezing point of the product without the product freezing. The freezing point of most raw meats is around −1.5 °C; owing to the presence of salts and other substances in processed meats their freezing points may be substantially lower than this. The presence of preservatives, such as salts and nitrates, in many cured meats also inhibit many pathogens, as does the low water activity, aw, of dried meat products. Packaging atmospheres are also a great aid in preventing the growth of many aerobic pathogens. 23.2.3 Impact of freezing on processed meat safety Little data exist on the impact of the initial freezing process on the safety of processed meats. However, it is difficult to envisage any sensible freezing process that would result in processed meat being held for substantial periods at temperatures that would support a dangerous growth of pathogens. 23.2.4 Impact of frozen storage and display on processed meat safety Providing the meat product does not rise above −12 °C during frozen storage and display, there are no issues of meat safety with frozen storage and display. 23.2.5 Impact of chilling on processed meat quality The chilling process can have an impact on processed meat quality in terms of appearance and weight loss. With a number of wrapped processed

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

577

meats, it is important to control the cooling of the meat and the casing to prevent the casing wrinkling. Some fibrous casings need to be kept moist during the initial stages of cooling to allow them to contract as the meat shrinks during cooling (Feiner, 2006). Similarly, too rapid cooling of re-formed hams cooked in moulds can lead to problems of integrity as different muscles may shrink at different speeds during cooling and removing such products from their mould before sufficient cooling has been occurred may lead problems on slicing (Feiner, 2006). Using too cold a temperature during chilling has also been cited as causing problems, since surface freezing may damage gel structures in re-formed meat products (Feiner, 2006). The choice of cooking and cooling method used for cooked processed meats, such as hams and cooked meat joints, can have a significant effect on weight losses during production. As well as having an important economic impact, this can affect the quality of meat. A comparison of combined processes is shown in Table 23.5. In these trials, convection cooling always required longer than immersion, and vacuum cooling was always the fastest cooling method. Combining all the treatments the average cooling time for convection, immersion and vacuum cooling were 433, 298 and 50 minutes, respectively. Weight losses after vacuum cooling (average 8.2%) were significantly greater than after convention cooling (2.5%). Overall, weight losses after convection or immersion cooking and cooling were not significantly different when processing any of the beef joints. The pressure/vacuum technique produced significantly greater overall weight losses than ether convection or immersion processing. Average weight losses for all treatments for convection, immersion and pressure/vacuum processing were 31.3, 27.5 and 45.8%, respectively. Although higher throughputs can be achieved using the pressure/vacuum process the high weight losses may be prohibitive for commercial use with thick joints. Increased losses during pressure-cooking are probably due to the high surface temperatures achieved during the process, and evaporative loss during vacuum cooling is an inherent requirement of the process. However, the addition of intermittent water sprays during the process may reduce weight loss. It is possible that a hybrid system, possibly using convection cooking in bags followed by immersion cooling, could optimise yields with large meat joints.

23.2.6 Impact of chilled storage and display on processed meat quality In general, there is little difference in the microbial spoilage of beef, lamb, pork and other meat derived from mammals (Varnam & Sutherland, 1995). The spoilage bacteria of meats stored in air under chill conditions include species of Pseudomonas, Brochothrix and Acinetobacter/Moraxella. Different species become important in the spoilage of vacuum packaged and modified atmosphere packaged meats, with lactic acid bacteria forming the principle spoilage organism.

© Woodhead Publishing Limited, 2011

578

Processed meats

Table 23.5 Processing times and weight losses from meat under different cooking and cooling regimes (all joints cooked from 5 °C to an internal temperature of 75 °C for beef, 80 °C for ham and 85 °C for turkey then cooled to a maximum internal temperature of 10 °C) Processing conditions Cooking

Type of joint*

Time (min.) Beef m. semi. Convection1 Immersion2 Pressure/vacuum3 Beef forequarter Convection Immersion Pressure vacuum Beef silverside Convection Immersion Pressure/vacuum Boneless turkey Convection Immersion Pressure/vacuum Boneless ham Convection Immersion Pressure/vacuum

Wt loss (%)

Cooling Time (min.)

Overall

Wt loss (%)

Time (min.)

Wt loss (%)

120 71 50

26.6 – 32.4

150 100 52

2.7 – 9.5

270 171 102

29.3 32.7 41.8

225 208 110

26.7 – 38.0

390 282 43

2.3 – 7.9

615 489 153

28.9 25.5 45.9

219 227 104

28.4 – 39.2

338 240 61

3.3 – 7.4

557 467 165

31.8 30.0 46.6

360 457 207

32.7 – 37.8

526 411 36

1.8 – 7.8

886 867 243

34.5 25.9 46.7

389 429 203

29.9 – 39.6

761 456 57

2.2 – 8.6

1150 885 260

32.1 23.6 48.2

* Beef joints were obtained from 18 month old Hereford steers. Silverside (mean 2.7 kg) and forequarter joints (mean 2.7 kg) were prepared to produce rolled joints approximately 11 cm in diameter and m. semitendinosus to produce slabs (5 × 9 × 21 cm, 0.94 kg). Boned-out ham (mean 7.2 kg) and turkey (mean 6.4 kg) joints were obtained from a local producer. All the joints were frozen and thawed before cooking. 1 Each joint was cooked in air at 120 °C, 0.5 m s−1 and a 75 °C dew point followed by cooling in air at 0 °C and 1.2 m s−1. 2

3

Each joint was vacuum packed and then heated in agitated water at 95 °C then cooled in water at 0 °C.

Carried out in a vessel operating at 100 kpa (15 psi) followed by vacuum cooling.

Temperature is the principal factor affecting the rate of microbial growth and hence the shelf-life of many chilled processed meats. Basically the lower the temperature the longer the storage life. The influence of temperature on the storage life of vacuum packed sliced cured meat products is shown clearly in Table 23.6. The type of packaging and atmosphere will also have a significant effect on shelf-life. Cured meats, such as ham, bacon, luncheon meat and frankfurters, will have a shelf-life of 12–15 days at 4 °C in standard

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

579

Table 23.6 Storage life for vacuum packed sliced cured meat products (adapted from Bøgh-Sørensen & Olsson, 1990) Storage life (days) Temperature (°C)

12 8 5 2 0 −3

Bologna sausage

Smoked fillet

7 11.5 21.5 33 42 11

– 9 10 11.5 22.5 33

Cooked pork loin 21 33 66 78 141 165

Cooked pork loin – 16.5 31.5 52.5 64 >64

packaging, depending upon the degree of curing, but vacuum-packaging may extend this to up to 5 months at 4 °C. In some meats lipid oxidation will limit shelf-life. Studies by Tanchotikul et al. (1989) have shown that the susceptibility to oxidation in pre-cooked roasts during chilled storage increased as the end-point cooking temperature increased. Addition of 0.25 or 0.5% polyphosphate to restructured, battered and breaded, cooked, beef and pork nugget products protected them from off-flavours and lipid oxidation during chilled storage (Huffman et al., 1987). Similar effects have been shown for onion and garlic juices (Jurdi-Haldeman et al., 1987). The appearance of processed meat at its point of sale is the most important quality attribute governing their purchase. Consumers prefer brightred fresh meats, brown or grey-coloured cooked meats and pink cured meats (Cornforth, 1994). Illumination during display is particularly important with cured meat products. Light catalyses the dissociation of nitric oxide from both raw and cooked cured meat pigment, causing them to brown, particularly in the presence of oxygen (Rankin, 1984). The colour of fresh sausages using paprika oleoresin is also affected by light, oxygen and temperature (Feiner, 2006). Therefore illumination should ideally be kept low for such products and careful rotation of stock is advisable. Air movement and relative humidity have little effect on the display life of a wrapped processed meat products, but the degree of temperature control can be important especially with transparent, controlled atmosphere packs. During any control cycle, the cabinet temperature rises, heat enters the pack, the atmosphere inside the pack warms with consequent reduction in relative humidity and increase in the surface temperature of the product. As the surface temperature rises so does its saturation vapour pressure (a factor controlling evaporation) and more water evaporates into the sealed atmosphere of the pack. If the cabinet temperature stabilised then evaporation would continue until the atmosphere became saturated. However, in practice the cabinet air temperature cycles and as it is reduced the wrapping film is cooled. If it reaches a temperature below the dew point

© Woodhead Publishing Limited, 2011

580

Processed meats

of the atmosphere inside the pack then water vapour will condense on the inner surface of the pack. This film of water can obscure the product and consequently reduce consumer appeal. As the cycling process continues the appearance of the product deteriorates. Surveys (Bøgh-Sørensen, 1980; Malton, 1971) have shown that temperatures of packs from the top of stacks were appreciably higher than those from below due to radiant heat pick up from store and cabinet lighting. It has also been stated that products in transparent film overwrapped packs can achieve temperatures above that of the surrounding refrigerated air due to radiant heat trapped in the package by the ‘greenhouse’ effect. However, specific investigations failed to demonstrate this effect (Gill, 1984). Deterioration in the appearance of unwrapped processed meats is mainly related to the degree of dehydration, which makes the product unattractive to consumers (James & Swain, 1986). The rate of dehydration is a function of the temperature, air velocity and especially the relative humidity of the air passing over the surface of the meat on display. Reducing the relative humidity from 95 to 40% can increase the rate of dehydration by a factor of 18. Changing the type of illumination can also change the rate of dehydration (Evans & Russell, 1994a,b). Changing the lighting combination of 50 W sodium (SON) lights and 100 W halogen lights to the 100 W sons and a colour 83 fluorescent significantly increases the weight loss, equivalent to a 20% reduction in relative humidity.

23.2.7 Impact of freezing on the quality of processed meats There is a belief in the meat industry that freezing can damage the quality of products such as ham, resulting in ‘a dry as well as tasteless product’ (Feiner, 2006); however, there is little scientific evidence to support this view. In fact, most studies have failed to find a difference between the quality of chilled and frozen processed meats, such as ham (Jeremiah, 1982; Cilla et al., 2006) or bacon (Jeremiah, 1982). For example, Cilla et al. (2006) compared the quality of vacuum-packaged boneless dry-cured hams and vacuum-packaged dry-cured ham cuts stored chilled (4 °C; 8 months) or frozen (−18 °C; 24 months). Instrumental colour and texture, physico-chemical and biochemical parameters, sensory profile and consumer acceptability and purchase satisfaction were all measured throughout storage. Freezing appeared to slow the rate of textural changes by a factor of 3 compared with refrigerated storage. The authors concluded that ‘neither of these storage systems caused sufficient modification of ham quality so as to result in lower acceptance by consumers’. However, there can be problems with the freezing of some re-formed processed meats. Not all starches commonly used in these meat products are freeze–thaw stable. In general, most native starches, such as wheat and potato starch, have very poor freeze–thaw stability, while modified starches high in amylopectin have good freeze–thaw stability (Feiner, 2006).

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

581

There is also a general view that fast freezing offers some quality advantage, with ‘quick frozen’ appearing on many meat products with the expectation that consumers will pay more for a ‘quick frozen’ product. However, there is little in the literature to suggest that, in general, the method of freezing, or the rate of freezing, has any substantial influence on the quality characteristics or final eating quality of processed meats.

23.2.8

Impact of frozen storage and display on the quality of processed meats Three factors are commonly believed to have the main influence on the frozen storage life of processed meats: (1) the storage temperature, (2) the degree of fluctuation in the storage temperature, and (3) the type of wrapping/packaging in which the meat is stored. Desiccation from the surface tissues produces a dry, spongy layer that is unattractive and does not recover after thawing. This is commonly called ‘freezer-burn’. It occurs in unwrapped or poorly wrapped meat. The problem is accentuated in areas exposed to low humidity air at high velocities, and by poor temperature control. As well as causing a quality loss there is an economic loss as well, due to weight loss. Figure 23.2 shows clearly the detrimental effect of both air movement and high storage temperatures on weight loss of frozen unwrapped processed meats (Malton & James, 1984). Although weight losses per day in frozen storage are small, since storage times can be long, consequent overall losses can be as high as 10%, from hams for instance (Roussel & Sarrazin, 1970).

°C

°C

°C

10 8.1 % weight loss

8

7.2 6.4

6 4 2

5.2

5.1 4 3.2

2.8

2.8

4.2

2.2

1.8

1.7

3.6

0.8

0 30

80

120

225

340

Days in storage

Fig. 23.2 Weight loss from unwrapped hams in frozen storage.

© Woodhead Publishing Limited, 2011

582

Processed meats

Since most meat is now wrapped and temperature control much improved, this is less of a problem than it once was commercially. However, despite popular belief to the contrary, such packaging does not completely eliminate weight loss. Evaporative losses from polyethylene-wrapped meat frozen at −30 °C are negligible, but losses of up to 0.5% have been recorded at −10 °C. The slower freezing time due to the warmer temperature allows water to migrate from the meat to the inner surface of the polyethylene. Provided problems of freezer burn can be eliminated, the major appearance problem that affects frozen meat arises from oxidation of oxymyoglobin to metmyoglobin. Both temperature and illumination level affect the rate of discoloration during frozen storage, but light is by far the more serious factor. The major problem in retail marketing of frozen meats is their appearance. The freezing process causes changes in the structure and colour of the muscle, and the deterioration in appearance during frozen storage and display ultimately leads to rejection of the product by the consumer. Storage temperature, light intensity on the display area and method of packaging all affect the rate of deterioration. The appearance of fresh processed meats are a primary factor in acceptability at retail level and the same criteria of attractiveness will apply to their frozen equivalents, retailed either frozen or after thawing. The poor colour of the frozen product, and the drip associated with it when it thaws, have in the past both contributed to consumer resistance. The appearance of frozen meat is markedly improved if retail-sized portions are first packed in film to exclude air between the meat surface and the film and then rapidly frozen. With this product, however, the price differential between fresh and frozen would necessarily be small and the consumer would have to be persuaded by the trade that such frozen meat was in no way inferior to fresh.

23.3 Advances in technology and practice to improve processed meat safety and quality Many of the current advances in refrigeration technologies are concerned with improving the quality of frozen products. In general, these technologies are based on the assumption that fast, or rapid, freezing offers some quality advantage over conventional slow freezing, and that the formation and maintenance of small ice crystals are better than large ice crystals. While this may be important with some foods, there is little in the literature to suggest that, in general, the rate of freezing, has any substantial influence on the final eating quality of any processed meats. In fresh unprocessed meat there is some evidence for a relationship between freezing rate and drip production during thawing. Petrovic et al. (1993) stated that the optimal conditions for freezing are those that achieve freezing rates between 2 and 5 cm h−1 to −7 °C. Grujic et al. (1993) suggested

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

583

even tighter limits of 3.33–3.95 cm h−1. These results are scientifically very interesting; however, in industrial practice most meat is frozen in air in the form of large individual pieces or cartons of smaller pieces. Under these conditions, freezing rates of 0.5 cm h−1 would be considered fast. The authors do not know of any reliable data that relate drip loss during thawing with the eating quality of fresh or processed meats. 23.3.1 Superchilling The drive to maximise the storage and display lives of perishable foods has led to increasing interest in holding foods in the region between their freezing point and −12 °C. This is a grey area in terms of much international legislation, since food is not usually considered fully ‘frozen’ until it is below −12 °C and only considered ‘chilled’ above its freezing point. The initial freezing point of fresh lean meat is typically −1.5 °C and in a processed meat with a salt content of 2, 3, 4 and 5% salt it would be −3.2, −4.4, −5.5 and −6.7 °C respectively (James et al., 2005). The terms ‘super-chilled’, ‘deepchilled’, ‘ultra-chilled’ or ‘partially frozen’ are often used for foods held in this temperature region; the Japanese also use the term ‘Hyo-on’. Confusingly some in the food industry also use similar terms for chilled foods that are simply held below 0 °C, or use the terms ‘super-chilling’, ‘deep-chilling’ or ‘hard-chilling’ for the process of using refrigerating temperatures below 0 °C (also commonly referred to as ‘rapid’ or ‘ultra-rapid’ chilling). Where freezing occurs during the process, before equalising at the required storage temperature, terms such as ‘crust-freezing’ and ‘partial-freezing’ may also be used. To yet further confuse matters some foods can be held significantly below their freezing point without freezing (i.e. nucleation of ice crystals), this is usually referred to as ‘sub-cooled’ or ‘super-cooled’. In the context of this section ‘super-chilling’ is a refrigeration process that aims to maximise storage and display lives of perishable foods without resorting to full freezing. Typically it is based on storage at temperatures just below the initial freezing point; low enough to substantially reduce bacterial activity but high enough to avoid levels of ice crystal growth that can cause structural damage. For many processed meats these temperatures are the range −1.5 to −4 °C, at which (depending upon composition) about 30–50% of water in the product is ice (Aune, 2003). Studies on cured and roast pork have reported super-chilling to extend the shelf-life of such products. A storage-life of >56 days has been reported in cured pork loin stored at −3.5 °C (Bøgh-Sørensen & Zeuthen, 1984). Holding roast pork legs at −1.1 °C, has been reported to extend storage-life to up to 35 days (Haugland et al., 2005). 23.3.2 Crust freezing In the traditional production of sliced ham, formed ham logs are cooled over 2 to 7 days in cold rooms to a core temperature of 2 °C (Lammertz &

© Woodhead Publishing Limited, 2011

584

Processed meats

Brixy, 2001). The logs are cut in 1.5 mm thick slices using standard slicers at rates up to 500 slices per minute. New high rate slicers operate at rates up to 1000 slices per minute. To produce high quality slices at this rate the ham logs have to be crust frozen to a temperature of −5 °C at a depth of 7 mm. A number of different cryogenic freezers have been developed to perform the crust freezing process (Lammertz & Brixy, 2001).

23.3.3 Tempering Tempering operations are used to produce the optimum texture in a chilled product so that it is suitable for mechanical processing. Crust-freezing is often used for the same purpose, but is essentially a less controlled process where only the surface is frozen. In tempering, product is semi-frozen so that it is stiff enough to be sliced, cubed, etc. without deformation. Reducing deformation during cutting improves the yield, by enabling faster cutting, and reducing the number of misshapen slices. However, the process must be carefully controlled. The optimum tempering temperature is a function of the meat and the slicer. Obtaining the correct temperature throughout the meat joint is crucial for a high yield of undamaged slices for products such as bacon (James & Bailey, 1987). High-speed photography has been used to clearly demonstrate the effect of incorrect slicing temperature. If too much of the water in the meat is frozen, the subsequent sliced, diced or chopped meat is likely to show a large increase in the amount of drip released. Also when the temperature is too low the hard meat may shatter and blade wear is excessive. When the temperature is too high the soft meat will deform and may stick to the blade and the fat may be torn away from the lean. A number of problems are inherent in a single-stage tempering operation. Equalisation times are long: after 18 hours there can still be a 3 °C differential across the backs. The most obvious drawback of single-stage tempering is that to obtain the same throughput systems have to be far larger, probably by at least 3-fold. It is also more difficult to obtain even air distribution and good temperature control in a large room. This problem is exacerbated in that the single-stage system has to fulfil conflicting roles. To remove heat from the bacon a reasonable air/product temperature difference and air movement are required. In contrast, towards the end of the process when all the required heat has been extracted, a very small temperature differential and minimum air movement are desirable to attain an even temperature and a reduced rate of weight loss. In a two-stage tempering process, an initial blast freezing operation is followed by a separate period of temperature equalisation. Using a twostage system for six hours resulted in differentials of less than 1 °C. It is critical that the desired amount of heat is extracted in the initial blast freezing operation.

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

585

23.3.4 High pressure freezing High pressure freezing and in particular ‘pressure shift’ freezing is attracting considerable scientific interest (LeBail et al., 2002). The meat is cooled under high pressure to sub-zero temperatures but does not undergo a phase change and freeze until the pressure is released. Rapid nucleation results resulting in small even ice crystals. However, studies on pork and beef (Fernández-Martín et al., 2000) have failed to show any real commercial quality advantage.

23.3.5 Magnetic resonance freezing A Japanese patented system called CAS (Cells Alive System) freezing, which involves magnetism and modulated waves of cold air, has been marketed by ABI (Japan) for enhanced freezing and frozen storage of foods (Dodd, 2004; Anon, 2006). There is currently very little independent data on this system, beyond claims from the companies marketing the system. The CAS technology claims to ‘retain the texture and flavour of food’ (Dodd, 2004; Anon, 2006) by enhancing supercooling of the product, achieved by subjecting the target product with a low intensity magnetic field, prior to freezing (essentially the same aim as pressure-shift freezing). Supercooling allows the entire body of the product to be uniformly cooled below the freezing point without freezing occurring. Then, when the magnetics are turned off, the product freezes quickly and uniformly, ‘suppressing the migration of fats and oils, and the formation of ice crystals’ (Anon, 2006). It is also reported that ‘pulsating air minimizes the formation of ice clustering’, the food is also pulsed ‘with an oscillating magnetic field during storage’ which is reported to reduce bacteria numbers and allow ‘the products to be kept for two to three years, or even longer’ (Dodd, 2004).

23.4 Future trends As with the rest of the food industry, processed meat producers are under increasing pressure to reduce their unit production costs while maintaining, if not improving, the safety and quality of the products they produce. Optimising the refrigeration of processed meats can increase throughput, maximise yield and reduce energy consumption. Extracting heat from cooked meat tends to be a slow process and chilling/freezing is often the longest process in a production process. Heat flow from the centre of the product is governed by the thermal conductivity of the processed meat and its thickness. In many cases the composition and thickness of the meat is fixed and cannot be easily changed. However, the rate of heat extraction from the surface is a function of the refrigeration system used.

© Woodhead Publishing Limited, 2011

586

Processed meats

The use of impingement technology to increase the surface heat transfer in chilling and freezing systems has received attention (Everington, 2001; Newman, 2001; Sundsten et al., 2001) and commercial systems are now available. Impingement is the process of directing a jet or jets of fluid at a solid surface to effect a change. The very high velocity (20–30 m s−1) impingement gas jets ‘break up’ the static surface boundary layer of gas that surrounds a meat product. The resulting medium around the product is more turbulent and the heat exchange through this zone becomes much more effective. Impingement freezing/chilling is best suited for products with high surface area to weight ratios, e.g. hamburger patties or products with one small dimension. Testing has shown that products with a thickness less than 20 mm freeze most effectively in an impingement heat transfer environment. When freezing products thicker than 20 mm, the benefits of impingement freezing can still be achieved; however, the surface heat transfer coefficients later in the freezing process should be reduced to balance the overall process efficiency. The process is also very attractive for products that require very rapid surface freezing and chilling. When cooked meat is removed from the cooker the rate of evaporative weight loss from the hot wet surface is very high. Rapid surface cooling as achieved in impingement will significantly reduce the rate of loss. The increasing use of spray/evaporative cooling will also substantially improve the yield and is likely to be increasingly used as a front end add on to conventional chillers. To reduce energy consumption used in refrigeration and the total meat processing operation a number of simple technologies are expected to be widely adopted. Since products exit cookers with temperatures approaching 100 °C or higher the use of ambient air at 20 °C produces initial cooling rates that are not substantially slower than using refrigerated air. Where space is available the use of ambient coolers will substantially reduce the load on refrigeration system and consequently the cost of operation. Currently one-third of the heat load in a blast chiller or freezer comes from the fans used to circulate the air over the meat being cooled. At the initial stages of cooling high air velocities are critical to rapidly reduce the surface temperature of the food. However, once the surface temperature is within a few degrees of the ambient they are not required. Intelligent control systems that substantially reduce the energy consumption of fans using information on product temperature are likely to be increasingly introduced. Finally in a cooked meat operation energy is used to raise the temperature of the product during cooking. Then a following cooling operation uses energy to reduce the temperature of the meat back to close to its initial temperature. Air cycle refrigeration has the potential to use a single plant to provide both the cooking and cooling requirements in a very efficient manner. Such a system is currently under development (Evans et al., 2007).

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

587

23.5 References anon (1987), ‘Rapid cooling of ham,’ Chemical Engineering Group Report No. 2. Institute of Food Research – Bristol Laboratory, Langford. anon (2006), ‘Cold treatments,’ Meat Industry Services, Food Science Australia. aune e j (2003), ‘Superchilling of foodstuff, a review’, 21st International Congress of Refrigeration, IIR/IIF, Washington, US. ICR0127. bøgh-sørensen l (1980), ‘Product temperature in chilled cabinets’ Proceedings of the 26th European Meeting of Meat Research Workers, Colorado (USA). Paper no. 22. bøgh-sørensen l and olsson p (1990), ‘The chill chain’, In Chilled Foods: The state of the art, Ed. Gormley, T. R. Elsevier Applied Science, London, Chapter 12, 245–267. bøgh-sørensen l and zeuthen p (1984), ‘The validity of the TTT-concept on the shelf lives of chilled, cured meat products’, Proceedings of the European Meeting of Meat Research Workers, 30, Section 5:5, 223–224. burfoot d, self k p, wilkins t j and james s j (1990), ‘Effect of cooking and cooling method on the processing times, mass losses and bacterial condition of large meat joints’, International Journal of Food Science & Technology, 25, 657–667. cfisig (2004), Food Retail and Food Services Code. Canadian Food Inspection System Implementation Group. cilla i, martinez l, beltrán ja and rocalés p (2006), ‘Effect of low-temperature preservation on the quality of vacuum-packaged dry-cured ham: Refrigerated boneless ham and frozen ham cuts’. Meat Science, 73(1), 12–21. codex alimentarius commission (1999), Code of Hygienic Practice for Refrigerated Packaged Foods with Extended Shelf Life, CAC/RCP 46-(1999). Food and Agriculture Organization of the United Nations. cook o d (1985), ‘A cooling rate survey comparing rapid chill refrigeration and walk-in refrigeration in chilling cooked foods’. Dairy and Food Sanitation, 5, 204–208. cornforth d (1994), ‘Colour-its basis and importance’. In Quality Attributes and Their Measurement in Meat, Poultry and Fish Products (Eds. A. M. Pearson and T. R. Dutson). Advances in Meat Research Series, Volume 9, Blackie Academic & Professional, UK. Chapter 2, 34–78. de jong a e i, rombouts f m and beumer r r (2004), ‘Effect of cooling on Clostridium perfringens in pea soup’. Journal of Food Protection, 67(2), 352–356. dodd j (2004), ‘Out of the ice age: technology to freeze by’. Japan Inc. Communications. http://findarticles.com/p/articles/mi_m0NTN/is_57/ai_n6118032 (accessed 17 December 2008). ec (2004), Regulation (EC) No 852/2004 of the European Parliament and of the Council of 29 April 2004 on the hygiene of foodstuffs. european chilled food federation (1996), ‘Guidelines for good hygienic practice in the manufacture of chilled foods’. evans j a and russell s l (1994a), ‘The influence of surface conditions on weight loss from delicatessen products’, FRPERC – Internal report, August 1994. evans j a and russell s l (1994b), ‘The influence of surface conditions on weight loss from delicatessen products’, FRPERC – Internal report, November 1994. evans j, russell s and james, s. (1996), ‘Chilling of recipe dish meals to meet cook– chill guidelines’. International Journal of Refrigeration, 19(2), 79–86. evans j a, russell s, james c and corry j e l (2004) ‘Microbial contamination of food refrigeration equipment’. Journal of Food Engineering, 62, 225–232. evans j a, gigiel a j, foster a m and brown t (2007), ‘Air cycle combined heating and cooling’. The 22nd International Institute of Refrigeration International Congress of Refrigeration. August 21–26, Beijing, China.

© Woodhead Publishing Limited, 2011

588

Processed meats

everington d w (2001), ‘Development of equipment for rapid freezing’. In Rapid Cooling of food, Meeting of IIR Commission C2, Bristol (UK), Section 2, 173–180. feiner g (2006), Meat Products Handbook. Woodhead Publishing, Cambridge. fernández-martín f, otero l, solas m t and sanz p d (2000), ‘Protein denaturation and structural damage during high-pressure-shift freezing of porcine and bovine muscle’, Journal of Food Science, 65(6), 1002–1008. fsai (2004), Guidance note no. 15: ‘Cook-chill systems in the food service sector’. Food Safety Authority of Ireland, Dublin, Ireland. gaze j e, brown g d, gaskell d e and banks j g (1989), ‘Heat resistance of Listeria monocytogenes in homogenates of chicken, beef steak and carrot’. Food Microbiology, 6, 251–259. gaze j e, shaw r and archer j (1998), ‘Identification and prevention of hazards associated with slow cooling of hams and other large cooked meats and meat products’. CCFRA Review No. 8, Project No. 16286. gill c o (1984), ‘The greenhouse effect’. Food April, 47, 49, 51. grujic r, petrovic l, pikula b and amidzic l (1993), ‘Definition of the optimal freezing rate – 1’. Meat Science, 33(3), 301–318. haugland a, aune e j and hemmingsen a k t (2005), ‘Superchilling – innovative processing of fresh food’. EuroFreeze 2005: Individual Quick Freezing of Foods, Proceedings of EU Workshop (Project QLK1-CT-2002-30544), 13–15 January 2005, Sofia, Bulgaria, 1–8. huffman d l, ande c f, cordray j c, stanley m h and egbert w r (1987), ‘Influence of polyphosphate on storage stability of restructured beef and pork nuggets’. Journal of Food Science, 52(2), 275–278. james s j (1990a), ‘Cooling systems for ready meals and cooked products’. In Process Engineering in the Food Industry: 2 Convenience Foods and Quality Assurance. Ed. R.W. Field and J.A. Howell. Elsevier Science Publishers, London 88–97. james s j (1990b), ‘Cooling of cooked products’. Proceedings of International Institute of Refrigeration Commissions B2, C2, D1, D2/3, Dresden, Germany Paper 30. james s j (1990c), ‘The cooling of cooked meat products’. Proceedings of the Institute of Mechanical Engineering Conference on Future Meat Manufacturing Processes, London. james s j and bailey c (1982), ‘The measurement of product load during cooling, freezing and thawing of meat and meat products’. Proceedings Institute of Refrigeration, 77, 44–51. james s j and bailey c (1987), ‘Bacon tempering for high speed slicing’. XVIIth International Congress Refrigeration, Vienna, C2-1. james s j and swain m v l (1986), ‘Retail display conditions for unwrapped chilled foods’, The Proceedings of the Institute of Refrigeration, 83, Session 1986– 87, 3.1 james c, lejay i, tortosa n, aizpurna x and james s j (2005), ‘The effect of salt concentration on the freezing point of meat simulants’. International Journal of Refrigeration, 28, 933–939. jeremiah l e (1982), ‘The effects of frozen storage and thawing on the retail acceptability of ham steaks and bacon slices’. Journal of Food Quality, 5(1), 43–58. jurdi-haldeman d, macneil j h and yared d m (1987), ‘Antioxidant activity of onion and garlic juices in stored cooked ground lamb’. Journal of Food Protection, 50, 411–413, 417. lammertz m and brixy n (2001), ‘Continuous process and production improvements by application of refrigeration with cryogenic gases’. Rapid Cooling of Food, Meeting of IIR Commission C2, Bristol (UK) Paris: International Institute of Refrigeration, 119–126.

© Woodhead Publishing Limited, 2011

Impact of refrigeration on processed meat safety and quality

589

lebail a, chevaliera d, mussaa d m and ghoul m (2002), ‘High pressure freezing and thawing of foods: a review’. International Journal of Refrigeration, 25(5), 504–513. malton r (1971), ‘Some factors affecting temperature of packaged overwrapped trays of meat in retailers’ display cabinets’. Proceedings of the 17th Meeting European Meat Research Workers, 486. malton r and james s j (1984), ‘Using refrigeration to reduce weight loss from meat’, Proceedings Symposium. Profitability of Food Processing – 1984 Onwards – The Chemical Engineers Contribution, Pub. Institute of Chemical Engineering, 207–217. maria g t, abril j and casp a (2005), ‘Surface heat transfer coefficients for refrigeration and freezing of foods immersed in an ice slurry’, International Journal of Refrigeration, 28, 1040–1047. mead g c, allen v m, burton c h and corry jel (2000), ‘Microbial cross-contamination during air chilling of poultry’. British Poultry Science, 41, 158–162. mcdonald k and sun d (2000), ‘Vacuum cooling technology for the food processing industry: a review’. Journal of Food Engineering, 45, 55–65. newman m (2001), ‘Cryogenic impingement freezing utilizing atomized liquid nitrogen for the rapid freezing of food products’. In Rapid Cooling of Food, Meeting of IIR Commission C2, Bristol, UK. nolan e j (1986), ‘Chilling time estimates for cooked roast beef when using a liquid coolant’. Fleischwirtschaft, 66(11), 1625–1626. petrovic l, grujic r and petrovic m (1993), ‘Definition of the optimal freezing rate2.’ Meat Science, 33, 319–331. rankin m d (1984), Notes on Meat Products. Leatherhead Food R. A., Leatherhead, Surrey, UK. roussel l and sarrazin p l (1970), ‘Weight losses in unwrapped hams after freezing and storage’. Weight Losses in Foodstuffs, Meeting of IIR Commissions II, IV, V & VII, Leningrad (USSR). Annexe 1970-3 Bulletin IIR, 209–214. sundsten s, andersson a and tornberg e (2001), ‘The effect of the freezing rate on the quality of hamburgers’. Proceedings of the International Institute of Refrigeration Rapid Cooling – Above and below zero, Bristol, UK. tanchotikul u, godber j s, arganosa g a, mcmillin k w and shao k p (1989), ‘Oxidative stability and textural quality of restructured beef roasts as affected by end-point cooking temperature, storage and the incorporation of surimi’. Journal of Food Science, 54(2), 280–283 uk department of health (1989), ‘Chilled and frozen. Guidelines on Cook–Chill and Cook–Freeze Catering Systems’. varnam a h and sutherland j p (1995), Meat and Meat Products, Chapman & Hall, London.

© Woodhead Publishing Limited, 2011

24 Recent advances in the application of high pressure technology to processed meat products Y. Ikeuchi, Kyushu University, Japan

Abstract: There is a growing interest in consuming processed meat products that are healthy and safe. High pressure technology is expected to serve as an alternative to conventional technologies or to generate a synergetic effect to produce new meat products, because pressurization at low or moderate temperatures affects microorganism activity in meat products, while making fewer changes to the sensory quality, thereby increasing the shelf-life. In addition, products may acquire new sensory attributes that can be appreciated by consumers. Recent information on and future trends in high pressure technology for the meat industry are reviewed. Key words: high hydrostatic pressure, pascalization, meat processing, meat products, meat quality, meat gelling, microbial inactivation.

24.1 Introduction In recent years, the application of high hydrostatic pressure (HHP) to food processing, which is an innovative alternative to thermal-treatment or chemical preservatives, has attracted worldwide attention because apparatus for HHP treatment has become commercially available (Engineered Pressure Systems, Inc., Haverhill, Mass.; Stansted Fluid Power, Essex, UK; NC Hyperbaric, Burgos, Spain; Ishikawajima-Harima Heavy Industry Co. Ltd, Japan). Meanwhile, efforts are also being made to demonstrate the potential benefits of high pressure technology for the preservation and modification of foods including meat and meat products (Torres and Velazquez, 2005). In Japan, the Japanese Society of High Pressure Science for Food was established in 1986 to promote a wider use of high pressure (Hayashi, 1992). Since then, many papers regarding high pressure processed

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

591

foods have been published, and the studies culminated in the release of the world’s first high pressure processed food called ‘high pressure jam’, to the food markets in 1992 (Meidiya Food Company, Japan). HHP used for food processing has the advantage of affecting only noncovalent bonds of macromolecules in food constituents. This means that while heat causes nutritional loss (such as of vitamins), the production of unpleasant smell and abnormal materials, HHP generally keeps natural taste, flavor and nutrients of foods. High pressure can, however, influence most biochemical reactions including enzymatic reactions and may change the food morphology (Pandrangi and Balasubramaniam, 2005). Thus, pressure effects on the structure, texture, flavor and color of foods may be profitable. From the food industry perspective, high pressure is beneficial as an energy-saving technique because it is not necessary to use further energy to hold the pressure once the desired pressure is reached. Moreover, when high pressure is applied to foods, its effect is instant, uniform and independent of their size and shape. High pressure in combination with other physical methods can induce new biological and biochemical effects. For example, high pressure treatment of rice enhances the amount of gamma-aminobutyric acid (GABA), which is known to lower blood pressure. This phenomenon is called high pressure-induced transformation (Hi-Pit), which will contribute to various food industries such as the medical health, brewing and fermented food industries (Sasagawa et al., 2006). In Japan, this has been applied to develop high pressure processed foods termed ‘Pascal foods’ advertised as ‘Tastier’, ‘Safer’ and ‘Healthy’. In this way, high pressure technology has the potential to produce novel foods that contain nutritional and functional ingredients, which meet the growing need of health-conscious customers. Meanwhile, high pressure technology is currently being used in processing cooked meat products. In Spain, high pressure treatment is being used to extend the shelf-life of ham products that are normally heated and wrapped and to prevent the secondary contamination of raw hams (Grèbol, 2002). MacFarlane (1973, 1985), one of the most highly regarded researchers in high pressure technology for meat and meat processing, reported the improvement in pressurized meat tenderness and muscle gel in the 1970s. After this pioneering research, the effects of pressure on meat and meat products were investigated extensively by many meat researchers (Cheftel and Culioli, 1997; Hugas et al., 2002; Suzuki et al., 2006). The major applications of high pressure technology for meat processing had been well documented by Cheftel and Culioli (1997). In their review, general principles underlying the effects of HHP on foods, particularly meats, were also described. In this chapter, the author introduces recent data concerning the specific effects of high pressure on mostly meat products. The present situation and future view of high pressure technology for meat industry are also described.

© Woodhead Publishing Limited, 2011

592

Processed meats

24.2 Effect of high pressure on the quality of meat and meat products The quality attributes of processed meat products are greatly dependent on various aspects of meat materials. Thus, the effects of high pressure treatment on water-holding capacity (WHC), color, lipid oxidation and flavor in raw meat or meat products are briefly outlined below.

24.2.1 WHC WHC is defined as the ability of meat to retain its water when external force such as heating, pressing or grinding are applied. Much of the water in meat exists in myofibrils by capillary action, and about 5% of water binds to the hydrophilic groups of amino acids in muscle proteins. Thawing and heating cause the decrease of WHC accompanied by some increase in the exudative meat juice (meat pigments, amino acids, nucleotides, etc.) into the meat surface (drip loss) and the deterioration of meat quality such as texture, flavor or appearance. When pork meat is subjected to high pressure of 100 MPa, the drip loss increases because the myofibrils shorten. An increase in pressure from 200 to 300 MPa reduces the drip loss, thereby contributing to an increase in free water content in meat (Okamoto and Suzuki, 2002). This may be because the space that is able to maintain water increases via the partial destruction of structure of myofibrils, probably because of depolymerization of actin filaments. The application of high pressure to meat also leads to release of divalent cations that bind to myofibrillar proteins due to the electrostatic effect, preventing the formation of salt bridges among myofibrils. As a result, increased moisture retention in meat is achieved by muscle fiber expansion (swelling) caused by enhanced electrostatic repulsions. The drip loss increased again with a further rise in pressure to 400 MPa, indicating the severe denaturation of myofibrillar proteins.

24.2.2 Meat color Meat color is mainly determined by the amount and types of myoglobin and the scattering properties of meat (MacDougall, 1983). Denaturation of myoglobin caused by high pressure treatment is not observed below 235 MPa at 20 °C, while at 10 °C it is not observed until 500 MPa (Zipp and Kauzmann, 1973; Defaye et al., 1995). Recently, structural changes of myoglobin in meat induced by high pressure have been studied in detail by using spectroscopic analytical methods such as resonance Raman spectroscopy (Wackerbarth et al., 2009). Information regarding the pressure stability of myoglobin in meat has been provided by some research groups (Carlez et al., 1995; Cheah and Ledward, 1997a; Jung, 2003). In minced beef packaged under vacuum or

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

593

oxygen, relatively low pressure such as 100–200 MPa causes slight meat brightness (from intense red to light red), whereas further high pressure results in significant change in meat color to pale pink at 300 MPa and to white and gray at 400 MPa (pascalized meat color), which is similar to cooked meat color (Carlez et al., 1995). High pressure treatment reduces the extractability of myoglobin in meat. Moreover, an increase in meat metmyoglobin is associated with a decrease in oxymyoglobin. The color stability is improved when beef muscle 2 days post-slaughter is stored at 4 °C after being pressurized at about 100 MPa (i.e. the redness in appearance lasts for a while.), indicating that high pressure retards the formation of metmyoglobin (Cheah and Ledward, 1997a). However, high pressure may have no effect on the color of meats stored for more than one week. This is probably due to inactivation of enzymes that are involved in reducing metmyoglobin during storage. Meat discoloration caused by high pressure treatment above 300 MPa could be explained by the following: (1) libration of the heme portion from the pigment associated with the pressure-induced denaturation of the globin protein and (2) conversion of reduced myoglobin into oxidized myoglobin. In the latter case, removal of oxygen by vacuum packaging, addition of antioxidants or the formation of nitosylmyoglobin by addition of nitrite prior to pressurization is helpful to prevent the pigment from oxidation (Carlez et al., 1995; Goutefongea et al., 1995). The whitening of the meat by pressure is fairly suppressed by vacuum-sealing with deoxidizer or addition of nitrite. In practice, the dark reddish color of raw ham (nitrosomyoglobin) or a bright pink color of cooked ham (nitrosomyochromogen) is resistant to pressure and does not change easily. High pressure treatment induces the reduction of pH in meat, so that it will promote the partial denaturation of globin and dissociation heme of the pigment, and in addition oxidation of the heme. Furthermore, high pressure treatment has a great effect on activities of metmyoglobin-reducing enzymes and myoglobin-oxidizing enzymes, and also accelerates the oxidation of heme caused by the oxidized lipids. Therefore, how the color in the fresh meat pressurized changes will be unpredictable, but the pressure effect in the color of the processed meats will be not significant.

24.2.3 Lipid oxidation Lipid oxidation is mainly responsible for deterioration of the stored meat and meat products especially rich in unsaturated fatty acids. Rising levels of the oxidized materials not only impair the meat flavor or lead to loss of nutrition value, but also are major contributors to cancer or heart disease. Cheah and Leward (1995, 1996, 1997b) studied the effect of high pressure on lipid oxidation in pork meat in detail. The isolated lipids of pork were not affected by high pressure, but the rate of oxidation was accelerated when the pressure treatment above 300 MPa at room temperature was

© Woodhead Publishing Limited, 2011

594

Processed meats

applied to the muscle tissue. High pressure treatment does not affect the auto-oxidation of lipids isolated from pork meat or fishes (Ohshima et al., 1993), but stimulates fatty acid oxidation in meat and fish muscles (Wada, 1992). Thiobarbituric acid (TBA) value, which is the level of oxidation, of beef remains unchanged up to 200 MPa, but increases sharply at above 300 MPa. Packaging in nitrogen prevented lipid oxidation of the pressurized minced meat, but during subsequent storage both pressurized samples in air and nitrogen were oxidized more rapidly than untreated ones (Cheah and Ledward, 1996). The reason why pressure could enhance lipid oxidation is not precisely known, but one possible explanation is that the denatured ferric form of myoglobin, which occurs by pressurization, plays a role in the catalysis of the lipid oxidative reaction. Metal chellators such as citrate and ethylenediaminetetraacetic acid are very effective inhibitors of pressureinduced lipid oxidation in pork. Metal ions may play an important role in the acceleration of lipid oxidation, since other antioxidants such as rosemary extract (Beltran et al., 2004) and butylhydroxyanisol (BHA) (Cheah and Ledward, 1997b) are less effective. This idea was not confirmed by Orlien et al. (2000), who rather emphasized that it could be linked to membrane damage. However, when the meat is pressurized under oxygen-free conditions, the oxidation of lipids is minimal. The effect of high pressure on the stability of lipids depends on meat ingredients, water activity, temperature (raising the temperature on pressurizing accelerates the oxidative reaction), and storage condition except for oxygen. High pressure treatment at 20–40 °C causes decreases in oxidative stability of a range of muscle foods, including beef, pork, and chicken; beef is less stable than pork and chicken is the most stable (Ma et al., 2007). In meat, the oxidation of lipids induced by pressure is said to start under the condition of 300 MPa at 20–25 °C. McArdle et al. (2010) assessed the combined effects of HPP and temperature on meat quality attributes in bovine m. pectoralis profundus, with particular focus on lipid oxidation and fatty acid profile. Although an increase in thiobarbituric acid reactive substance (TBARS) values was observed at the higher pressure levels (300, 400 MPa) and HPP at 40 °C showed higher saturated (SFA) and polyunsaturated (PUFA) and lower monounsaturated (MONO) acids compared to HPP at 20 °C, high pressure had no effect on polyunsaturated/saturated fatty acid (PUFA/SFA) or omega 6/omega 3 (n6/ n3) ratios. From these results, they concluded that high pressure at low (200 MPa) or moderate temperatures (20 °C) improves the microbiological quality of the meat with minimal effects on meat quality. However, it may be possible to inhibit the pressure-induced oxidation of lipids in meat and meat products by use of antioxidants or anoxic or carbon dioxide packages. After all, pressure-induced lipid oxidation in meat products cannot be prevented unless suitable packaging or antioxidants are used. Dry-cured meat products are well-known for their unique sensory characteristics. The flavor characteristics of dry sausages result from

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

595

a combination of spices, meat endogenous enzyme activities, microbial activities, autoxidation processes and the interaction among odorous compounds. Serra et al. (2007) demonstrated that high pressure treatment (400 and 600 MPa) slightly reduced antioxidant enzyme activity in dry cured hams. Fuentes et al. (2010) reported that the oxidation of Iberian dry cured ham lipids and proteins was enhanced by HHP treatment (600 MPa for 6 min) and pre-slicing dry-cured ham results in a more susceptible product to oxidative reactions during pressurization and subsequent refrigerated storage (at 4 °C for one month). Rubio et al. (2007) reported that HHP treatment (500 MPa, 5 min, storage at 6 °C for up to 210 days) had no noticeable effect on the lipid oxidation of vacuum-packed ‘salchichón’, drycured sausages in Spain, even though this product is rich in monounsaturated and polyunsaturated fatty acids, suggesting that it improves the food safety of salchichón with no detrimental effects on organoleptic properties. It is generally believed that the addition of antioxidants could enhance the quality of meat and meat products, stabilizing free radicals and delaying the reaction of lipid oxidation. Thus, Tume et al. (2010) hypothesized that elevating the concentration of alpha-tocopherol in beef muscle tissue by dietary means would increase lipid stability following high-pressure processing, but the obtained result was against their hypothesis.

24.2.4 Flavor The compounds responsible for taste and ‘meaty’ flavor (i.e. a reducing sugar, amino acids, peptides and inosinic acid (IMP)) increase with extended periods of conditioning. Proteolysis, and lipolysis, as well as lipid oxidation, Maillard reactions and Strecker degradations, play a role in the development of flavor of meat products, especially during the ripening period. Thus, it is important to study the effect of HHP treatment on the flavor development in meat products. Application of high pressure at 100–300 MPa to beef meat promotes an increase in the free amino acid content during storage at low temperature (Ohmori et al., 1991; Suzuki et al., 1994). This suggests that proteases released from the lysosome by pressurization hydrolyze muscle proteins to low molecular weight compounds such as amino acids and peptides during aging (Ohmori et al., 1992; Homma et al., 1994; Jung et al., 2000; Buckow et al., 2010). Suzuki et al. (1994) reported that the content of IMP, one of the flavorrelated components in meat, in the extracts from the pressurized muscles immediately after pressurization was apparently higher than that from untreated muscle, indicating that high pressure treatment has no adverse effect on the accumulation of ‘umami’ taste. Rapid reduction in ATP with a concomitant increase in IMP was observed when pork muscle immediately after slaughter was subjected to high pressure from 20 to 200 MPa for 10 min (Mouri et al., 1996; Mori et al., 2007a). Probably, high pressure

© Woodhead Publishing Limited, 2011

596

Processed meats

treatment first induces activation of myofibrillar ATPase and subsequently induces an increase in the production of IMP through nucleotide catalytic enzymes. IMP is produced by a series of actions of nucleotide catabolic enzymes including myokinase, AMP deaminase and 5′-nucleotidase. Naturally the capacity for producing IMP in meat is dependent on the pressurestability of these enzymes. The results of Mori et al. (2007b) demonstrated that AMP deaminase in extract from the pressurized muscle still retained high enzymatic activity at 300 MPa, but the activities of IMP-NT and AMP-NT extracted from the pressurized muscles decreased remarkably between 250 and 450 MPa. Myokinase was pressure-resistant up to 450 MPa. Therefore, pressure ranges from 100 to 200 MPa, which are usually applied for tenderizing meat, slightly impair the conversion of ATP to AMP followed by deamination to produce IMP in meat. Reports related to the effect of HHP treatment on the flavor of drycured ham include the recent papers of Campus et al. (2008) and RivasCanedo et al. (2009). Campus et al. (2008) reported that pressure treatment after the ripening of dry cured loin caused a reduction of several flavor compounds, particularly those derived from Maillard reactions and produced a reduction in the activity of aminopeptidases and dipeptidylpeptidases. In contrast, according to Rivas-Canedo et al. (2009), the application of high pressure to sliced Serrano ham, to increase product shelf-life, did not markedly modify its volatile fraction except that only a few compounds decreased with treatment.

24.3

Pressure-processed meat products

24.3.1 Pressure-induced gelation of muscle proteins Generally, high temperature leads to the irreversible denaturation of proteins because of covalent bond breaking and/or aggregation of unfolded ones. In contrast, pressure-induced denaturation is often reversible from 100 to 400 MPa. Even though covalent bonds in protein molecules are not destroyed by pressure, pressures above 200 MPa, in some cases, cause: (1) the dissociation of oligomeric protein structures into their subunits, (2) partial unfolding and denaturation of monomeric structure, (3) protein aggregation due to intertwining between the unfolded proteins, and (4) protein gelation is pressure and protein concentration are high (Chapleau et al., 2002). Gel formation, which is one of the most important functional properties of food, is attributed to new protein–protein interactions among denatured proteins due to heat treatment. Meat products such as sausage and ham and surimi products are produced by taking advantage of this property. Heatinduced gelation of the salt-soluble myofibrillar proteins, mainly myosin and actin, leads to the formation of a three-dimensional network that exhibits viscoelastic properties and high WHC (Asghar et al., 1985). Myosin is

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

597

essential for this gelation, but actin is also important as a cofactor reinforcing this gel structure of myosin (Yasui et al., 1980). Pressure, of course, denatures the muscle proteins, especially myosin, actin and actomyosin, depending on the extent of applied pressure, pH, salt concentration and so on (Ikkai and Ooi, 1966, 1969; O’Shea et al., 1976; Chapleau et al., 2004). Therefore, it can be utilized for developing new meat products that are unique in texture. Many studies have expected an improvement in functional properties of muscle proteins such as gelling property by application of high pressure (Carballo et al., 2001; Fernández-Martín et al., 2002; Jiménez-Colmenero, 2002). Suzuki and Macfarlane (1984) first reported that pressurization of myosin in 0.1–0.4 M NaCl solution (pH 6.0) at 150 MPa for 10 min prior to heating increased the heat-induced gel strength. Myosin is in the monomeric state in a high ionic strength solution, but exists as filaments at low ionic strength. Yamamoto et al. (1990) examined the effect of high pressure treatment on myosin at low salt concentration (0.1 M KCl, pH 6.0) and found that myosin filaments formed gels at 210 MPa and a protein concentration of above 3 mg/ml, but no pressureinduced gelation was observed at 140 MPa. The microstructure of the pressure-induced myosin gel consisted of a fine network similar to that of heat-induced myosin filament gel at low ionic strength. F-actin undergoes irreversible denaturation in the absence of ATP at a pressure of above 150 MPa, whereas ATP shows a significant protective effect against pressure-induced denaturation of actin (Ikkai and Ooi, 1966; Ikeuchi et al., 2002). In actomyosin, a gel to sol transition is prompted as a result of pressure treatment (Ikkai and Ooi, 1969). Suzuki (1991) showed that pork actomyosin pressurized at 200–400 MPa had higher work done values (breaking energy) than unpressurized actomyosin. Excellent heat-induced gels of actomyosin at low and high salt concentrations were produced by pressure at 150 MPa and pH 6.0 (Ikeuchi et al., 1992a). Ikeuchi et al. (1992b) examined the mechanism of heat-induced gelation of pressurized rabbit actomyosin and concluded that pressure effects on the heat-induced gelation of actomyosin were attributable to the pressure-induced denaturation of actin in actomyosin, the increased SH content and surface hydrophobicity (Chapleau et al., 2002). Gelation of pressurized muscle proteins (e.g. actomyosin) opens up the possibility of developing new meat products. For example it will be possible to reduce preservatives such as salt and nitrite, phosphate or fat in processed meat products after pressure treatment without compromising the safety and overall quality.

24.3.2

Development of pressure-processed meat products as a healthy food Consumers demand high quality meat products that are safe, healthy and natural products without additives such as preservatives, polyphosphates or

© Woodhead Publishing Limited, 2011

598

Processed meats

nitrite (Ruusunen and Puolanne, 2005; Desmond, 2006). To meet individual needs, it is necessary to use ever-more innovative technical means in the meat industry. High pressure technology enabled us to try to develop such consumer acceptable new meat products. Sodium chloride in meat products is an essential ingredient providing a number of different functionalities. Salt plays important roles in meat products: (1) to prevent the spoilage of processed meat products, (2) to give meat products their characteristic flavor and (3) to give proper water–fat retention and acceptable textural properties of meat gels. In role 3, salt influences the solubility of the myofibrillar proteins, which contributes to the stabilization of meat emulsion, thereby forming an elastic gel matrix in meat products (Desmond, 2006). This effect is dependent on the level of salt directly. Therefore, reduced salt use can be detrimental to the formation of heatinduced gelation of meat batters. Nitrite is widely used in the processed meat industry because it is an excellent preservative agent inhibiting the growth of Clostridium botulinum, contributes to the development of flavor in cured meat products, is responsible for the formation of characteristic pink/red color in cured and smoked products, retards development of rancidity, off-odours and offflavors during storage, inhibits development of warmed-over flavor, and preserves flavors of spices, etc. Regardless of the manufacturing benefits, a reduction in the use of nitrites is essential to diminish the risk of the formation of nitrosamines that are known carcinogenic substances. However, the consumer wants even greater reductions in or even elimination of the use of nitrate than the currently approved levels in meat products. The beneficial effects of phosphates in meat processing are also well known. In general, phosphates enhance the solubility of myofibrillar proteins through actomyosin dissociation and depolymerization of thick and thin filaments by increasing pH and ionic strength in meat, resulting in improvement of WHC and cooking yield. Thus, the gel characteristics cannot usually be improved when phosphates are not used. Meat products such as emulsified or coarsely ground sausages may contain up to 25–35% fat. High fat meat products should be avoided by those who are prone to cardiovascular diseases and/or who are overweight. However, reduction of fat in meat emulsions and meat products also alters the texture, binding properties and taste (Cavestany et al., 1994). To limit these drawbacks, the effect of high pressure on the properties of meat products produced by the addition of a variety of salt, fat, nitrite and so on has been examined. When the salted meat homogenates were pressurized at 25–250 MPa at 0 °C, the solubility of muscle proteins and WHC was elevated. This effect, due to pressurization, was dependent on pH, but the WHC did not increase below pH 5.3 (Macfarlane, 1973). In general, divalent cations (e.g. Mg2+, Ca2+) reduce the WHC of meat, because they weaken the electrostatic repulsions of negative charges in myofibrils, resulting in less water being immobilized in the myofibril lattices. The lack

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

599

of space for water molecules with myofibrillar proteins is known as a steric effect on water binding. The application of high pressure to meat leads to the release of divalent cations that bind to myofibrillar proteins due to the electrostatic effect, preventing the formation of salt bridges among myofibrils. As a result, increased moisture retention in meat is achieved by muscle fiber expansion (swelling) caused by enhanced electrostatic repulsions. Addition of salt to meat homogenate promotes the dissociation of divalent cations from myofibrils, contributing to further increase in WHC. However, when meat homogenates were cooked after pressurization, the binding ability among the meat particles was reinforced, leading to strong gel formation (Macfarlane et al., 1984). At this time, cooking loss increased a little at low salt concentration of 0.05%, but decreased at 1.3%. The binding ability and cooking loss strongly depended on pressure intensity and pressure time, but the binding ability of meat homogenates pressurized at 150 MPa increased regardless of salt concentrations (0, 0.5, 1.0 and 3.0%). It was assumed that the dissociation of myosin filament, depolymerization of actin or unfolding of muscle proteins by pressure treatment involved in the improvement of the binding ability. These results suggested that high pressure treatment allowed the functionality of muscle proteins to maintain or enhance even if additive amount of salt reduced in meat processing. The most basic sausage consists of meat, both beef and pork, cut into pieces, mixed with water, fat, seasonings and other ingredients including nitrite and polyphosphates prior to being stuffed into a casing, and then cooked during processing. Mandava et al. (1994) investigated the physicochemical and sensory characteristics of pressure-processed meat products made from meat emulsion containing comminuted pork meat (50–60%), fat (0–25%), water, salt (1.5–1.8%) and polyphosphates (0.05–0.3%). After vacuum-packing, the meat batters were treated with high pressure of 50–380 MPa at 10 °C for 5 min, followed by a smoke-cooked process. As a result, they succeed in producing frankfurter-type sausage with reduced fat, low salt and low polyphosphate that had less cooking loss and a certain degree of elasticity. Crehan et al. (2000) reported that the salt level can be reduced to 1.5% without any noticeable change in cook loss, and emulsion stability of the frankfurters could be improved with salt reduction, independent of the applied pressure level. No significant effects of HP treatment on the internal color and the overall flavor of the frankfurters were noticed. Sikes et al. (2009) demonstrated that salt level in meat batters could be further reduced to 1% using HPP (200 MPa, for 2 min at 10 °C), of which the product had similar, if not better, texture and cooked yield compared with the untreated HPP samples with normal (2%) salt equivalents. O’Flynn et al. (2000), Crehan et al. (2000) and Troy et al. (2001) also examined the application of HPP on the raw meat material used in the manufacture of low salt, low fat and low phosphate beefburgers, frankfurts and breakfast sausages without losing their original qualities and safety. Typical commercial beefburgers contain 23–25% fat, which is considered to

© Woodhead Publishing Limited, 2011

600

Processed meats

be too high by health-conscious consumers. However, the reduction of fat content in meat products would downgrade assessment of their organoleptic and textural properties. Then, they also examined an effect of the functional ingredient such as tapiocaline to compensate for the fat reduction. According to their report, overall texture scores were significantly higher for HPP sausages, although the evaluation of juiciness was low, possibly due to a lower level of fat. A reduction in use of salt possibly promotes microbial contamination during storage. However, HPP at 600 MPa could lower the microbial count of breakfast sausages. They emphasized that the HPP would produce the acceptable meat products although some modifications, further improvements of texture, juiciness or flavor, might be needed. In contrast, Jiménez-Colmenero et al. (1997) reported that pressure treatment prior to heating does not favor gelling ability because it causes a decrease in emulsion stability, possibly as a consequence of pressure-induced protein denaturation. The author’s group represents a completely different strategy to make a favorable manufacturing sausage at low salt and low fat without phosphates (Zhu et al., in preparation). Raw meat materials used for processing are converted to have suitable properties for producing a novel meat product mentioned above at the thawing stage by high pressure treatment. High pressure will reduce costs for thawing meat material because it is able to thaw the frozen meat in almost no time in the pressure vessel. The principle of this method is briefly as follows: frozen meat material is first pressurized at 150 MPa for 10 min, in which actin in the myofibrils is depolymerized, followed by denaturation. Simultaneously myosin filaments are easy to dissociate from myofibrils but still exist in their native form. Thus myosin molecules become more abundant in meat after pressure, forming a fine filamentous-type gel under conventional heat pasteurization at low salt (1%) even without polyphosphates (Hermansson et al., 1986; Yamamoto et al., 1990; Ikeuchi et al., 1992a,b). In general, polyphosphates improve cooking yield and WHC of meat product, but they are not required to make a filamentous-type meat product during the pressure thawing process because the dissociation of myosin from myofibril by them is no longer necessary. Digestion test in rats and sensory panel test of the manufactured sausages were performed to explore the acceptability in the marketplace. The results showed that pressure-processed sausage was not difficult to digest. Also, panelists estimated that meat product with low salt and low fat without polyphosphate was inferior to those made from untreated meat material. Panelists reported that texture of the HP-treated product was ‘too soft’. This is presumably the reason that they were not familiar with such a novel texture. Recently, Trespalacios and Pla (2007a) suggested that microbial transglutaminase (TGase), which has been used to improve the functional properties of meat gels by catalyzing formation of glutamyl–lysine bonds in myosin–myosin or myosin–actin, may help counteract effects of softening

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

601

of low fat protein gels obtained by pressure rather than heat treatment. Then, use of TGase to create structure or non-meat ingredients such as egg and milk proteins may be able to compensate for the decrease in firmness of the pressure-processed meat gels (Trespalacios and Pla, 2007a,b; Fulladosa et al., 2009).

24.3.3 Pressure-processed cooked ham Pressure-processed sliced cooked ham was introduced on the market in Spain in 1999 (Grèbol, 2002). Sliced cooked ham vacuum-packed with microfilm following conventional cooking was pressurized at 400 MPa for 10 min in a 320 liter industrial unit made by ACB Inc. HHP caused a significant reduction in the population, activity and growth capacity of microorganisms that would produce unpleasant flavor in the cooked ham. The products also had superior organoleptic qualities, which would be accepted by consumers, and a long shelf-life. In 2007, Itoham Foods Inc., Japan, started selling a special ham called ‘healthy ham without nitrite’ as a ‘Pascal food’. It was pressurized after vacuum-packaging at 600 MPa for 4 min at 10 °C (http://www.itoham.co.jp/english/index.html). According to the data released from the company, the pressurized ham did not increase in common bacteria number during 50-day storage at 10 °C, suggesting that pressure treatment is useful for quality extension and longer shelf-life while reducing dependence on preservatives. Sensory assessment by consumers was also within the allowable range regardless of nitrite-free ham. Bertram et al. (2006) pursued the possibility of replacing tumbling (intermittent vacuum tumbling for 6 h) with low pressure treatment (7 MPa for 4 s) in the production of a low salt cured ham.

24.3.4 Pressure-processed fermented sausage Fermented sausages are traditional products made by a traditional preservation technology of fermentation that provides relatively stable meat products with a unique and much appreciated flavor. HHP has been recommended to produce low-risk and high-quality fermented sausages (Garriga et al., 2005; Marcos et al., 2007) and shorten the drying period that is the limiting step of the manufacturing process in terms of time (Arnau et al., 2007). Haga and Ueshima (1997) applied high pressure to process fermented meat products. Cured pork meats were fermented with lactic acid bacteria at 5 °C for 4 weeks, and pressurized at 300 MPa for 15 min after 2 weeks’ fermentation. As a result, the growth of harmful Bacillus species was inhibited and flavor did not deteriorate in the products although the number of lactic acid bacteria decreased with increasing the pressure intensity. Interestingly, high pressure and pH reduction by addition of lactic acid bacteria caused changes in the ultrastructure of the fermented sausages, resulting in an excellent texture.

© Woodhead Publishing Limited, 2011

602

Processed meats

Garriga’s group in Spain evaluated the impact of the HHP under a variety of conditions such as the addition of bacteriocins or the addition of a starter culture on the microbial, chemical, physical and sensory properties of traditional Spanish low acid fermented sausages during ripening, and concluded that: (1) the use of high pressure treatment can be recommended as a final step in the manufacturing of low-acid fermented sausages with appropriate starter cultures, (2) the application of a HHP treatment alone or in combination with enterocins is necessary to decrease the levels of Salmonella and Listeria monocytogenes to obtain safe low acid fermented sausages and (3) the addition of starter culture and high pressure processing after ripening improved the microbial quality of low acid fermented sausages (Garriga et al., 2005; Marcos et al., 2007; Jofre et al., 2009a). Ananou et al. (2010) similarly reported AS-48 can be applied alone to control L. monocytogenes and combined with HHP treatment to control Salmonella in fuets, low acid fermented sausages.

24.3.5 Pressure-processed raw ham-like meat product Nose et al. (1992) developed a raw ham-like pork meat product using high pressure. Slices of cured pork meat were pressurized at 250 MPa for 3 hours at 20 °C following packing in plastic pouches under vacuum and smoking at 65 °C for 90 min in a smokehouse. During storage at 4 °C, no microbial growth and no changes in color, pH, water activity and moisture content were observed. The sensory assessment indicated that a pressure-processed new product like a raw ham, which did not sacrifice shelf-life or food safety, was acceptable to consumers. This pressure processing of pork ham had the advantages of shortening curing process in addition to the reduction in microbial level and extending the refrigeration life as pointed out by Arnau et al. (2007). Unfortunately, the National Authorities of Japan required further reliable and traceable safety on the grounds that it still did not meet the standards set by Japan’s Food Sanitation Law although there are no specific regulations in the EU, the US or Australia.

24.3.6

Development of pressured pre-cooked (partially prepared or oven ready) meat products Consumers want natural, ready-to-eat meat products that have fresh, justprepared characteristics without preservatives, but meat processors cannot sacrifice product shelf-life or food safety. High pressure technology will help make new types of pre-cooked meat products or pressure processed readyto-eat meat products (Hugas et al., 2002). Although the manufacture of this type of meat product increases the risk of microbial contamination, mainly during slicing and packaging, high pressure treatment at 600 MPa at 20–30 °C for 3–10 min reduced L. monocytogenes or Escherichia coli O157, inoculated the meat products and extended the refrigerated shelf-life of meat products

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

603

(Hayman et al., 2004; Gill and Ramaswamy, 2008). Of course, HPP treated meats retained their original sensory qualities such as texture, color and nutritional content throughout their shelf-life. In Japan, Matsutake et al. (1994) made a new type trial meat product and appeared on the test market. Raw meat is cut into a certain size and thick pieces are tumble-marinated in a vacuum-packed plastic bag and then pressurized. The obtained product showed new texture, improved sensory, longer shelf-life (sterilization effect) and good digestibility in a precooked state. Regrettably, it still remains unsuccessful in the market due to its high manufacturing cost. The use of packing materials which fully withstand high pressure should be taken into consideration for HPP processing packaged foods such as ready-to-eat meat products. Also, it is necessary to prevent the odor of packing material from being absorbed into the meats during pressurizing (Rivas-Canedo et al., 2009). The head space in the product should also be reduced to as little as possible when it is sealed: since high pressure accelerates the oxidation of lipid in the product, it is of importance to reduce the residual oxygen.

24.3.7 Development of meat products for dysphagia diet Nowadays, an increasing number of senior citizens have difficulty chewing and swallowing in addition to a general decline in physical performance. High pressure technology has been used in Japan to produce soft, smooth, highly nutritional meat products for patients suffering from dysphagia (Yoshioka et al., 2006). Pork meats blended with 50–100% of water, 1.0% NaCl and 0.05% rosemary extract were pressurized at 400 MPa for 20 min at 10 °C and then heated by a water oven until the central part of the samples reached 80 °C (pressure-heated gels). The obtained gels, which corresponded to the filamentous gel formed at low salt, were evaluated as preferable to heated ones in terms of luster, elasticity, fineness and ease of swallowing. Pressure-heated gels could therefore be utilized for dysphagia diets.

24.4 Microbial control in meat and meat products using high pressure Food preservation using high pressure is attractive to the food industry as it offers numerous opportunities for developing new food products with extended shelf-life and minimal changes in consumer appeal (FonbergBroczek et al., 2005). High pressure appears to inactivate food spoilage microbes such as yeast, bacteria and mold by denaturing the proteins in the microbe’s cell membrane, and enzymes related to metabolism or replication/transcription of DNA. This denaturation, if not repairable by the cell, prevents it from transferring water, ions and nutrients across its membranes,

© Woodhead Publishing Limited, 2011

604

Processed meats

and as a result the cell dies. The application of high pressure to the processing and preservation of foods has been under intensive investigation since early 1980s (Yuste et al., 2001; Mor-Mur and Yuste, 2005). Of course, conditions of high pressure for food sterilization such as the pressure level, the process of temperature and time and pH depend on the type of micro organisms, the various ingredients and the dispersion medium in foods. In the meat industry, high pressure is also an attractive method that can be used to sterilize without affecting the character and features of meat and meat products (Shigehisa et al., 1991; Cheftel, 1995; Garriga et al., 2004; Tassou et al., 2007; Aymerich et al., 2008; Jofre et al., 2009b). In general, Gram-negative bacteria are more susceptible to inactivation by high pressures than Gram-positive bacteria (Cheftel, 1995; Cheftel and Culioli, 1997). Also, pressure resistance is different among strains even in the same bacterial species. Listeria monocytogenes, which is Gram-positive, facultatively anaerobic and an ubiquitous foodborne pathogen that causes listeriosis, shows high pressure resistance even at 400–500 MPa, while Staphylococcus aureus, a Gram-positive bacterium, is one of the more resistant species of bacteria (above 700 MPa). The spore-forming bacteria (e.g. Clostridium botulinum) have very high pressure resistance, requiring pressures as high as 1000 MPa, which is well over the pressure produced by commercially highest hydrostatic pressure equipment, to kill them. However, the combination of high pressure at near 600 MPa and temperature at near 100 °C makes it possible to shortly inactivate them. This means that attempts to sterilize meat products by high pressure treatment fail. It may be better to add additives such as nitrite or possibly bacteriosins produced from lactic acid bacteria to inhibit the germination of spores. Akhtar et al. (2009) suggested a novel strategy for the inactivation of Clostridium perfringens (an anaerobic endospore-forming Gram-positive bacteria) spores in meat products by pressure-assisted thermal processing (e.g. 586 MPa at 73 °C for 10 min). The short time-pulse pressurization, the combination of heat and a series of pulsed pressure treatments and addition of chemical reagents are said to be more effective for inactivating the spores than long-term pressurization at certain pressure intensity in fruit juices (Vurma et al., 2006; Donsì et al., 2007). However, these methods remain untested in meat and meat products. The Gram-negative bacteria (e.g. E. coli O157:H7, Campylobacter jejuni) in growth phase are weak against pressure and in addition, they are likely to be more liable under the condition of low pH (Solomon and Hoover, 2004; Gill and Ramaswamy, 2008; Black et al., 2010). The weakness of high pressure sterilization is that it is not as effective as heat at killing food spoilage microbes. In addition, injured microbes may repair themselves under high nutrition condition, just like meat, during storage after pressurization, and then they may start growing again (Koseki et al., 2007). Also, as pressure possibly interferes with the effect of heat sterilization in case of certain bacteria, serious attention to condition setting is required when pressure

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

605

and temperature are used concurrently. Pressure resistance of bacteria becomes higher in foods containing proteins, fat and sugar and in foods of lower water activity than in aqueous solution (Hayman et al., 2008). Much research on the pressure resistance of bacteria present naturally or inoculated artificially to raw meat and meat products has found that pressure in the range of 400–500 MPa was required to destroy common bacteria. For example, when vacuum-packed frankfurt sausages were inoculated with L. monocytogenes followed by pressurization at 300, 500 and 700 MPa for 0–9 min at 20 °C, the high pressure processing reduced the microbial load by approximately 1, 3 l and 5 log cycles, respectively. Also, when the pressure was applied consciously for 9 min, decline of the bacteria to 5 log was observed even below 500 MPa. At 25 °C an inactivation ratio of 5 log cycles was achieved for treatment of 8 min at 300 MPa, 1.8 min at 700 MPa (Lucore et al., 2000). The application of HHP may inactivate lactic acid bacterial growth, extending the product shelf-life and preserving natural taste, color and texture. Slongo et al. (2009) studied the influence of pressure level and holding time on lactic acid bacterial growth in vacuumpackaged sliced ham and demonstrated that shelf-life of ham treated at 400 MPa for 15 min was extended from 19 (untreated samples) to 85 days. Combined high pressure–moderate temperature processing is beneficial for raising the efficiency of sterilization (Pandrangi and Balasubramaniam, 2005), but it is not applicable to raw meat because natural, unprotected meat pigment in the meat changes to a grey-brown color. However, according to recent reports of Forde et al. (2009) and Cruz-Romero et al. (2010), a combination of high pressure and mild heat is likely to increase shelf-life and improve overall acceptability of vacuum-packed pork meat and chicken meal during chilled storage. Under low water activity, HPP is thought to be less effective in inactivation of vegetative microbial cells (Pandrangi and Balasubramaniam, 2005). While it is necessary to drop the pH in foods below 4.5 to be certain of inhibiting the germination of spores such as Clostridium botulinum, Bacillus spores and other spore-forming bacteria, in raw meat such a condition is undesirable because an extreme pH decline causes the deterioration of the meat quality. Meanwhile, parasites, insects and insect eggs in raw meats can be inactivated or killed with relative ease at pressures in the range of near 200 MPa (Ohnishi et al., 1994). Recent reseach has introduced the use of bacteriocin to enhance the effectiveness of pressure sterilization (Chung et al., 2005; Jofré et al., 2007; Marcos et al., 2008a, b). As mentioned above, high pressure processing can eliminate manufacturing contamination by Salmonella, L. monocytogenes and other food borne pathogens in finished, packaged products without extremely adverse effects on color, flavor, texture and moisture. Therefore, pressure-assisted pasteurization and sterilization (at high temperature) are potentially useful applications, but extensive additional research on the inactivation of bacterial spores is still required.

© Woodhead Publishing Limited, 2011

606

Processed meats

24.5 New applications of high pressure technology in the meat industry 24.5.1 High pressure freezing and thawing Under HHP conditions, water behavior is unlike that under atmospheric pressure. For example, water freezes at 0 °C under atmospheric pressure, but decreases as pressure increases. In particular, water exists in the liquid state down to about −22°C at pressure up to 210 MPa. This property allows rapid freezing and thawing of foods through pressure applications. Principles and potential applications on pressure-assisted freezing and thawing have been well reviewed by several researchers (Cheftel et al., 2000, 2002; LeBail et al., 2002; Otero and Sanz, 2003). Rapid freezing by using a high pressure technology produces small ice crystals in food materials including raw meat, preventing their cellular damage (Fuchigami et al., 1997; Martino et al., 1998). Martino et al. (1998) compared the size and location of ice crystals in large meat pieces (Longissimus dorsi pork muscle) as a result of high pressure-assisted freezing with those obtained by air-blast and liquid N2 and reported that high pressureassisted frozen samples, both at the surface and at the central zones, showed similar, small-sized ice crystals. Frozen meats are conventionally thawed by various methods such as room air, water stream, heat, microwave and so on. The best method must be selected to adjust for the quality of frozen meat. Pressurization from 100 to 200 MPa allows rapid thawing of a part of the ice in frozen meat, leading to the reduction in running cost and improvement of the meat quality without damaging drip loss, color, organoleptic property and so on (Zhao et al., 1998; Massaux et al., 1999a,b; Okamoto and Suzuki, 2001, 2002). Furthermore, pressure-assisted thawing is expected to prevent the microbial growth in meat and convert the meat quality to a desirable form for a novel meat processing (see Section 24.3.2; Ikeuchi et al., 1992a,b). 24.5.2 Improvement of natural casing Natural sausage casings, used because of their crunchy texture, are composed chiefly of collagen fibers. However, low cost natural casings for mass production are of poor quality, particularly in terms of their strength and elasticity (Sakata, 2010). Nishiumi et al. (2009) attempted to soften the natural casing by high pressure treatment on the basis that it could dissociate collagen fibers or fibrils into fibrils in collage fiber networks (Ichinoseki et al., 2006) and found that high pressure weakened the collagen fibers in a different manner with organic acid treatment.

24.6

Future trends in high pressure processing

The disadvantage to the application of high pressure processing to meat is that it needs a great deal of initial investment compared with conventional

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

Cooked sliced ham, pork meat products and Parma ham Poultry ready-to-eat products Chicken fajita, chipotle chicken and chipotle beef dinners; smoothies Spicy sliced precooked chicken and beef for fajitas

USA (2001) USA (2001)

Thick sliced ham, chicken and turkey products. Cooked and Serrano ham, chorizo

Parma ham (Prosciutto), salami, mortadela

Gross slices of ham, turkey and chicken

Spain (2002)

Italy (2003)

Spain (2003)

USA (2002)

Delicatessen Cooked sliced ham and Tapas (pork and poultry cuts)

Spain (1998)

Product

Country (year)

600 MPa

500 MPa 4 to 10 min at 8 °C 600 MPa 10 min at 7 °C

400 MPa 10 min at 8°C

Process

Samples of HPP products in the market

Table 24.1

Vacuumpacked

Vacuumpacked Darfresh

Vacuumpacked

Darfresh Vacuumpacked and gas-packed Vacuumpacked Gas-packed plastic pouches

Packing

8 weeks

2 months or cooked products

21 days

2 months

Shelf-life

Sanitization without colour and taste modifications. Listeria destruction. The fajitas kit is made of high pressure processed meat but also high pressure processed onions, peppers and guacamole. Sanitization without colour and taste modifications. Listeria destruction. Increase of shelf-life and additives reduction. Sanitization without colour and taste modifications. Listeria destruction. Increase of shelf-life. Products for USA and Japan exports. Meat taste, fewer additives.

Sanitization without colour and taste modifications. Listeria destruction. Sanitization without colour and taste modifications. Listeria destruction.

Sanitization without colour and taste modifications.

Achievements of high pressure and comments

Campofrio, Spain

Vismara – Grupo Ferrarini, Italia

Campofrio, Spain

Fresherized Foods Avomex, USA

Hormel, USA

Espuña, Spain

Meat-packing company

© Woodhead Publishing Limited, 2011 600 MPa 5 min

Chicken fillet

HPP natural sausage

HPP poultry strips

USA

USA

Vacuumpacked

Vacuumpacked

Packing

>30 days

4 weeks

Shelf-life

Source: Modified from N.C. Hyperbaric SA, http://www.nchyperbaric.com/index.htm.

USA

USA

Ready-to-eat complete meals: meat carbs and vegetable RTE Natural Oven Roasted Chicken: Whole birds, breasts, drumsticks, thighs HPP ham, turkey, chicken

Cooked ham

600 MPa 5 min at 5 °C 600 MPa 2 min at 5 °C 600 MPa

250 MPa 3 h at 20 °C

Process

Cooked pork meat products nitrites-free: ham, sausages and bacon Smoked German ham: whole, sliced and diced products

Canada

Spain (2006) Spain

Germany (2005)

Japan (2005)

Raw ham-like pork ham

Product

Country (year)

Japan (2004)

Continued

Table 24.1

No preservatives.

Natural, minimally processed, no artificial ingredients.

Supper healthy ham with omega 3 free fatty acids and no added salt. High pressure processing marinated meat. Avoid discoloration. Pathogen control. Increase of shelf-life.

Sanitization. Listeria destruction. Products for USA export.

Shortening aging period and tenderization, microbial control, improved WHC and shelf-life. Acquisition of a permit for the sale of the products in 2004, but test market only. Sanitization. Increase of shelf-life (sold over the Internet).

Achievements of high pressure and comments

Oscar Mayer, USA Kayem Foods, USA Perdue Farms, USA

Campofrio, Spain Campofrio, Spain Maple leaf, Canada Tyson, USA

Abraham, Germany

Itoham, Japan

Fujichiku, Japan

Meat-packing company

Recent advances in the application of high pressure technology

609

thermal processing. Also, technical and economic difficulties with the commercial design and operation of equipment at the necessary pressures of between 100 and 1000 MPa remain. In particular, the introduction of the large-size, high pressure equipment, which is required to satisfy consumer demand for products with acceptable safety, leads to higher expenditure. When the purchase price of the equipment is high, meat processors usually pass the cost on to consumers. However, if the shelf-life of meat products can be extended by high pressure processing, the initial high investment on purchasing the equipment may not be an issue. Low cost machines that generate the pressure from 200 to 300 MPa are available for improving meat quality such as tenderness or the texture of meat products, while high cost machines equipped with heating device that generate above 600 MPa may be required for bacterial spore inactivation in meat products. Consumers currently show considerable concern regarding healthy foods, especially in demanding meat products with less salt, nitrite and polyphosphates. We need to consider how to balance consumer demand and the potential hazard of decline in food safety due to microbial contamination, but high pressure technology could make it possible to produce the meat products that contain less food additives. As mentioned above, if we are able to overcome contradictory propositions of high initial investment cost (commercial-scale high pressure machines) and benefits specific to high pressure processing, new pressure-processed meat products that meet the consumer demands of minimally processed food will be found in the market. Some meat-processing companies have been taking this challenge, as shown in Table 24.1. Consumers are ready to pay extra for new high pressue processing meat products if they have higher quality. It is essential that the quality and safety of the new product are assessed prior to launch on the market.

24.7 References akhtar s, paredes-sabja d, torres j a and sarker m r (2009), ‘Strategy to inactivate spores in meat products’, Food Microbiol, 26, 272–277. ananou s, garriga m, jofré a, aymerich t, galvez a, maqueda m, martinez-bueno m and valdivia e (2010), ‘Combined effect of enterocin AS-48 and high hydrostatic pressure to control food-borne pathogens inoculated in low acid fermented sausages’, Meat Sci, 84, 594–600. arnau j, serra x, comaposada j, gou p and garriga m (2007), ‘Technologies to shorten the drying period of dry-cured meat products’, Meat Sci, 77, 81–89. asghar a, samejima k and yasui t (1985), ‘Functionality of muscle proteins in gelation mechanisms of structured meat products’, CRC Crit Rev Food Sci Nutr, 22, 27–106. aymerich t, picouet p a and monfort j m (2008), ‘Decontamination technologies for meat products’, Meat Sci, 78, 114–129. beltran e, pla r, yuste j and mor-mur m (2004), ‘Use of antioxidants to minimize rancidity in pressurized and cooked chicken slurries’, Meat Sci, 66, 719–725.

© Woodhead Publishing Limited, 2011

610

Processed meats

bertram h c, wu z, straadt i k, aagaard m and aaslyng m d (2006), ‘Effects of pressurization on structure, water distribution and sensory attributes of cured ham: can pressurization reduce the crucial sodium content?’, J Agric Food Chem, 54, 9912–9917. black e p, hirneisen k a, hoover d g and kniel k e (2010), ‘Fate of Escherichia coli O157:H7 in ground beef following high-pressure processing and freezing’, J Appl Microbiol, 108, 1352–1360. buckow r, truong b q and versteeg c (2010), ‘Bovine cathepsin D activity under high pressure’, Food Chem, 120, 474–481. campus m, flores m, martinez a and toldrá f (2008), ‘Effect of high pressure treatment on colour, microbial and chemical characteristics of dry cured loin’, Meat Sci, 80, 1174–1181. carballo j, cofrades s, fernandez-martin f and jiménez-colmenero f (2001), ‘Pressure-assisted gelation of chemically modified poultry meat batters’, Food Chem, 75, 203–209. carlez a, veciana-nogues t and cheftel j c (1995), ‘Changes in color and myoglobin of minced beef meat due to high-pressure processing’, LWT-Food Sci Technol, 28, 528–538. cavestany m, colmenero f j, solas m t and carballo j (1994), ‘Incorporation of sardine surimi in bologna sausage containing different fat levels’, Meat Sci, 38, 27–37. chapleau n, delépine s and lamballerie-anton m (2002), ‘Effect of pressure treatment on hydrophobicity and SH groups interactions of myofibrillar proteins’, Trends High Press Biosci Biotechnol, 19, 55–62. chapleau n, mangavel c, compoint j p and lamballerie-anton m d (2004), ‘Effect of high-pressure processing on myofibrillar protein structure’, J Sci Food Agr, 84, 66–74. cheah p b and ledward d a (1995), ‘High-pressure effects on lipid oxidation’, J Am Oil Chem Soc, 72, 1059–1063. cheah p b and ledward d a (1996), ‘High pressure effects on lipid oxidation in minced pork’, Meat Sci, 43, 123–134. cheah p b and ledward d a (1997a), ‘Inhibition of metmyoglobin formation in fresh beef by pressure treatment’, Meat Sci, 45, 411–418. cheah p b and ledward d a (1997b), ‘Catalytic mechanism of lipid oxidation following high pressure treatment in pork fat and meat’, J Food Sci, 62, 1135–1139. cheftel j c (1995), ‘Review: high-pressure, microbial inactivation and food preservation’, Food Sci Technol Int, 1, 75–90. cheftel j c and culioli j (1997), ‘Effects of high pressure on meat: a review’, Meat Sci, 46, 211–236. cheftel j c, levy j and dumay e (2000), ‘Pressure-assisted freezing and thawing: principles and potential applications’, Food Rev Int, 16, 453–483. cheftel j c, thiebaud m and dumay e (2002), ‘Pressure-assisted freezing and thawing of foods: a review of recent studies’, High Pressure Res, 22, 601–611. chung y k, vurma m, turek e j, chism g w and yousef a e (2005), ‘Inactivation of barotolerant Listeria monocytogenes in sausage by combination of high-pressure processing and food-grade additives’, J Food Protect, 68, 744–750. crehan c m, troy d j and buckley d j (2000), ‘Effects of salt level and high hydrostatic pressure processing on frankfurters formulated with 1.5% and 2.5% salt’, Meat Sci, 55, 123–130. cruz-romero m, erdílal r, mullen a m and kerry j p (2010), ‘Effects of a combination of high-pressure and mild heat treatment on the microbiological and physicochemical quality of a convenience chicken meal during chilled storage’, 1st International Congress on Food Technology, November 3–6 2010. Antalya, Turkey.

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

611

defaye a b, ledward d a, macdougall d b and tester r f (1995), ‘Renaturation of metmyoglobin subjected to high isostatic pressure’, Food Chem, 52, 19–22. desmond e (2006), ‘Reducing salt: a challenge for the meat industry’, Meat Sci, 74, 188–196. donsì g, ferrari g and maresca p (2007), ‘Pulsed high pressure treatment for the inactivation of Saccharomyces cerevisiae: the effect of process parameters’, J Food Eng, 78, 984–990. fernández-martín f, cofrades s, carballo j and jiménez-colmenero f (2002), ‘Salt and phosphate effects on the gelling process of pressure/heat treated pork batters’, Meat Sci, 61, 15–23. fonberg-broczek m, windyga b, szczawin´ski j, szczawin´ska m, pietrzak d and prestamo g (2005), ‘High pressure processing for food safety’, Acta Biochim Pol, 52, 721–724. forde e e, cruz-romero m, mullen a m and kerry j p (2009), ‘Effects of a combination of high-pressure and mild heat treatment on the microbiological and physicochemical quality of pork meat during chilled storage’, Proceedings of the 39th Annual Research Conference Food, Nutrition & Consumer Sciences, University College Cork, Cork, 3S eptember, p. 68. fuchigami m, miyazaki k, kato n and teramoto t (1997), ‘Histological changes in high-pressure-frozen carrots’, J Food Sci, 62, 809–812. fuentes v, ventanas j, morcuende d, estevez m and ventanas s (2010), ‘Lipid and protein oxidation and sensory properties of vacuum-packaged dry-cured ham subjected to high hydrostatic pressure’, Meat Sci, 85, 506–514. fulladosa e, serra x, gou p and arnau j (2009), ‘Effects of potassium lactate and high pressure on transglutaminase restructured dry-cured hams with reduced salt content’, Meat Sci, 82, 213–218. garriga m, grèbol n, aymerich m t, monfort j m and hugas m (2004), ‘Microbial inactivation after high-pressure processing at 600 MPa in commercial meat products over its shelf life’, Innov Food Sci Emerg Technol, 5, 451–457. garriga m, marcos b, martin b, veciana-nogués m t, bover-cid s, hugas m and aymerich t (2005), ‘Starter cultures and high-pressure processing to improve the hygiene and safety of slightly fermented sausages’, J Food Protect, 68, 2341–2348. gill a o and ramaswamy h s (2008), ‘Application of high pressure processing to kill Escherichia coli O157 in ready-to-eat meats’, J Food Protect, 71, 2182–2189. goutefongea r, rampon v, nicolas n and dumont j p (1995), ‘Meat color changes under high pressure treatment’. In American meat science association. Proceedings of the 41st Annual International Congress of Meat Science and Technology, pp. 384. grèbol n (2002), ‘Commercial use of high hydrostatic pressure in sliced cooked ham in Spain’, in Hayashi R, Trends in High Pressure Bioscience and Biotechnology. Progress in Biotechnology, vol. 19, Amsterdam, Elsevier Science, pp. 385–388. haga s and ueshima r (1997), ‘Physical properties and ultrastructures of uncooked fermented meat products with high pressure treatment’, in Suzuki A and Hayashi R, High Pressure Bioscience and Technology, Kyoto, San-Ei Publishing Co., pp. 155 (in Japanese). hayashi r (1992), ‘Utilization of pressure in addition to temperature in food science and technology’, in Balny C, Hayashi R, Heremans K and Masson P, High Pressure and Biotechnology, Paris, Colloque INSERM/John Libbey Eurotec Ltd, vol. 224, pp. 185–193. hayman m m, baxter i, o’riordan p j and stewart c m (2004), ‘Effects of highpressure processing on the safety, quality and shelf life of ready-to-eat meats’, J Food Prot, 67, 1709–1718.

© Woodhead Publishing Limited, 2011

612

Processed meats

hayman m m, kouassi g k, anantheswaran r c, floros j d and knabel s j (2008), ‘Effect of water activity on inactivation of Listeria monocytogenes and lactate dehydrogenase during high pressure processing’, Int J Food Microbiol, 124, 21–26. hermansson a-m, harbitz o and langton m (1986), ‘Formation of two types of gels from bovine myosin’, J Sci Food Agr, 37, 69–84. homma n, ikeuchi y and suzuki a (1994), ‘Effects of high-pressure treatment on the proteolytic-enzymes in meat’, Meat Sci, 38, 219–228. hugas m, garriga m and monfort j m (2002), ‘New mild technologies in meat processing: high pressure as a model technology’, Meat Sci, 62, 359–371. ichinoseki s, nishiumi t and suzuki a (2006), ‘Tenderizing effect of high hydrostatic pressure bovine intramuscular connective tissue’, J Food Sci, 71, E276–E281. ikeuchi y, tanji h, kim k and suzuki a (1992a), ‘Dynamic rheological measurements on heat-induced pressurized actomyosin gels’, J Agr Food Chem, 40, 1751–1755. ikeuchi y, tanji h, kim k and suzuki a (1992b), ‘Mechanism of heat-induced gelation of pressurized actomyosin: pressure-induced changes in actin and myosin in actomyosin’, J Agr Food Chem, 40, 1756–1761. ikeuchi y, suzuki a, oota t, hagiwara k, tatsumi r, ito t and balny c (2002), ‘Fluorescence study of the high pressure-induced denaturation of skeletal muscle actin’, Eur J Biochem, 269, 364–371. ikkai t and ooi t (1966), ‘The effects of pressure on F-G transformation of actin’, Biochemistry, 5, 1551–1560. ikkai t and ooi t (1969), ‘The effects of pressure on actomyosin systems’, Biochemistry, 8, 2615–2622. jiménez-colmenero f (2002), ‘Muscle protein gelation by combined use of high pressure/temperature’, Trends Food Sci Tech, 13, 22–30. jiménez-colmenero f, carballo j, fernandez p, barreto g and solas m t (1997), ‘High-pressure-induced changes in the characteristics of low-fat and high-fat sausages’, J Sci Food Agr, 75, 61–66. jofre a, garriga m and aymerich t (2007), ‘Inhibition of Listeria monocytogenes in cooked ham through active packaging with natural antimicrobials and high-pressure processing’, J Food Protect, 70, 2498–2502. jofre a, aymerich t and garriga m (2009a), ‘Improvement of the food safety of low acid fermented sausages by enterocins A and B and high pressure’, Food Control, 20, 179–184. jofre a, aymerich t, grèbol n and garriga m (2009b), ‘Efficiency of high hydrostatic pressure at 600 MPa against food-borne microorganisms by challenge tests on convenience meat products’, LWT – Food Sci Technol, 42, 924–928. jung s, ghoul m and de lamballerie-anton m (2000), ‘Changes in lysosomal enzyme activities and shear values of high pressure treated meat during ageing’, Meat Sci, 56, 239–246. jung s, ghoul m and de lamballerie-anton m (2003), ‘Influence of high pressure on the color and microbial quality of beef meat’, Lebensm-Wiss Technol, 36, 625–631. koseki s, mizuno y and yamamoto k (2007), ‘Predictive modelling of the recovery of Listeria monocytogenes on sliced cooked ham after high pressure processing’, Int J Food Microbiol, 119, 300–307. lebail a, chevalier d, mussa d m and ghoul m (2002), ‘High pressure freezing and thawing of foods: a review’, Int J Refrig, 25, 504–513. lucore l a, shellhammer t h and yousef a e (2000), ‘Inactivation of Listeria monocytogenes Scott A on artificially contaminated frankfurters by high-pressure processing’, J Food Protect, 63, 662–664. ma h j, ledward d a, zamri a i, frazier r a and zhou g h (2007), ‘Effects of high pressure/thermal treatment on lipid oxidation in beef and chicken muscle’, Food Chem, 104, 1575–1579.

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

613

macdougall d r (1983), ‘Instrumental assessment of the appearance of foods’, in Williams A A and Atkin R K, Sensory Quality in Foods and Beverage: Its definition, measurement and control, Chichester, Ellis Horwood, pp. 121–129. macfarlane j j (1973), ‘Pre-rigor pressurization of muscle – effects on pH, shear value and taste panel assessment’, J Food Sci, 38, 294–298. macfarlane j j (1985), ‘High pressure technology and meat quality’, in Lawrie R, Developments in Meat Science, London, Elsevier Applied Science, pp. 155–184. macfarlane j j, mckenzie i j, turner r h and jones p n (1984), ‘Binding of comminuted meat – effect of high-pressure’, Meat Sci, 10, 307–320. mandava r, fernandez i and juillerat m (1994), ‘Effect of high hydrostatic pressure on sausage batters’, in TNO Nutrition and Food Research Institute, Proceedings 40th International Congress of Meat Science and Technology, S-VB 11. marcos b, aymerich t, guardia m d and garriga m (2007), ‘Assessment of high hydrostatic pressure and starter culture on the quality properties of low-acid fermented sausages’, Meat Sci, 76, 46–53. marcos b, jofre a, aymerich t, monfort j m and garriga m (2008a), ‘Combined effect of natural antimicrobials and high pressure processing to prevent Listeria monocytogenes growth after a cold chain break during storage of cooked ham’, Food Control, 19, 76–81. marcos b, aymerich t, monfort j m and garriga m (2008b), ‘High-pressure processing and antimicrobial biodegradable packaging to control Listeria monocytogenes during storage of cooked ham’, Food Microbiol, 25, 177–182. martino m n, otero l, sanz p d and zaritzky n e (1998), ‘Size and location of ice crystals in pork frozen by high-pressure-assisted freezing as compared to classical methods’, Meat Sci, 50, 303–313. massaux c, bera f, steyer b, cindic m and deroanne c (1999a), ‘High hydrostatic pressure effects on freezing and thawing of pork meat: quality preservation, processing times and high pressure treatment advantages’, in Ludwig H, Advances in Pressure Bioscience and Biotechnology, Heidelberg, Springer, pp. 485–488. massaux c, bera f, steyer b, cindic m and deroanne c (1999b), ‘High hydrostatic pressure effects on freezing and thawing of pork meat’, in Ludwig H, Advances in Pressure Bioscience and Biotechnology, Heidelberg, Springer, pp. 497–500. matsutake h, yamasaki t, haraguchi m and hatano k (1994), ‘Development of meat processed goods in the society for technical research of high pressure foods in Nagasaki’, in Kunugi S, Shimada S, Suzuki A and Hayashi R, High Pressure Bioscience, Kyoto, San-Ei Publishing Co., p. 280 (in Japanese). mcardle r, marcos b, kerry j p, mullen a (2010), ‘Monitoring the effects of high pressure processing and temperature on selected beef quality attributes’, Meat Sci, 86, 629–634. mor-mur m and yuste j (2005), ‘Microbiological aspects of high pressure processing’, in Sun D W, Emerging Technologies for Food Processing, London, Elsevier Academic Press, pp. 47–65. mori s, yokoyama a, iguchi r, yamamoto s, suzuki a, mizunoya w, tatsumi r, yoshioka k and ikeuchi y (2007a), ‘Effect of high pressure treatment on cytoplasmic 5′-nucleotidase from rabbit skeletal muscle’, J Food Biochem, 31, 314–327. mori s, uchida a, yamamoto s, sultana a, tatsumi r, mizunoya w, suzuki a and ikeuchi y (2007b), ‘Effect of high pressure on the accumulation of IMP and on the stability of AMP deaminase in rabbit skeletal muscle’, J Food Biochem, 31, 328–342. mouri s, yamashita h, hiraoka y, kan t and kurono m (1996), ‘Studies on the improvement in quality of fish and meat by high pressure treatment’, Bulletin of the Industrial Research Center of Ehime Prefecture, 34, 51–54 (in Japanese). nishiumi t, takaya y, nojiri t, ichinoseki s, suzuki a, yoon h and sakata r (2009), ‘Tenderizing mechanism of natural sausage casing using high hydrostatic pressure

© Woodhead Publishing Limited, 2011

614

Processed meats

in comparison to that by organic acid treatment’, Rev High Press Sci Technol, 19, 29P113. nose m, yamagishi s and hattori m (1992), ‘Development of a processing system of meat and meat-products by introducing high-pressure treatment’, in Balny C, Hayashi R, Heremans K and Masson P, High Pressure and Biotechnology, Paris, Colloque INSERM/John Libbey Eurotec Ltd, vol. 224, 321–323. o’flynn c, crehan c m, troy d j and buckley d j (2000), ‘The influence of high hydrostatic pressure on the functional properties of reduced-phosphate breakfast sausages’, Irish Journal of Agriculture and Food Research, 39, 138. ohmori t, shigehisa t, taji s and hayashi r (1991), ‘Effect of high-pressure on the protease activities in meat’, Agr Biol Chem, 55, 357–361. ohmori t, shigehisa t, taji s and hayashi r (1992), ‘Biochemical effects of high hydrostatic-pressure on the lysosome and proteases involved in it’, Biosci Biotech Biochem, 56, 1285–1288. ohnishi y, ono t and shigehisa t (1994), ‘Histochemical and morphological studies on Trichinella spiralis larvae treated with high hydrostatic-pressure’, Int J Parasitol, 24, 425–427. ohshima t, ushio h and koizumi c (1993), ‘High-pressure processing of fish and fish products’, Trends Food Sci Technol, 4, 370–375. okamoto a and suzuki a (2001), ‘Effects of high hydrostatic pressure-thawing on pork meat’, J Jpn Soc Food Sci, 48, 891–898. okamoto a and suzuki a (2002), ‘Effects of high hydrostatic-thawing on pork meat’, in Hayashi R, Trends in High Pressure Bioscience and Technology, Progress in Biotechnology, vol. 19, Amsterdam, Elsevier Science, pp. 571–576. orlien v, hansen e and skibsted l h (2000), ‘Lipid oxidation in high-pressure processed chicken breast muscle during chill storage: critical working pressure in relation to oxidation mechanism’, Eur Food Res Technol, 211, 99–104. o’shea j m, horgan d j and macfarlane j j (1976), ‘Some effects of pressure treatment on actomyosin systems’, Aust J Biol Sci, 29, 197–207. otero l and sanz p d (2003), ‘Modelling heat transfer in high pressure food processing: a review’, Innov Food Sci Emerg Technol, 4, 121–134. pandrangi s and balasubramaniam v m (2005), ‘High-pressure processing of salads and ready meals’, in Sun D W, Emerging Technologies for Food Processing, London, Elsevier Academic Press, pp. 33–45. rivas-canedo a, fernandez-garcia e and nunez m (2009), ‘Volatile compounds in dry-cured serrano ham subjected to high pressure processing. Effect of the packaging material’, Meat Sci, 82, 162–169. rubio b, martínez b, garcía-cachán m d, rovira j and jaime i (2007), ‘The effects of high pressure treatment and of storage periods on the quality of vacuum-packed “salchichón” made of raw material enriched in monounsaturated and polyunsaturated fatty acids’, Innov Food Sci Emerg Technol, 8, 180–187. ruusunen m and puolanne e (2005), ‘Reducing sodium intake from meat products’, Meat Sci, 70, 531–541. sakata r (2010), ‘Prospects for new technology of meat processing in Japan’, Meat Sci, 86, 243–248. sasagawa a, naiki y, nagashima s, yamakura m, yamazaki a and yamada a (2006), ‘Process for producing brown rice with increased accumulation of GABA using high-pressure treatment and properties of GABA-increased brown rice (in Jpanaese with English abstract)’, J Appl Glycosci, 53, 27–33. serra x, sarraga c, grèbol n, guardia m d, guerrero l, gou p, masoliver p, gassiot m, monfort j m and arnau j (2007), ‘High pressure applied to frozen ham at different process stages. 1. Effect on the final physicochemical parameters and on the antioxidant and proteolytic enzyme activities of dry-cured ham’, Meat Sci, 75, 12–20.

© Woodhead Publishing Limited, 2011

Recent advances in the application of high pressure technology

615

shigehisa t, ohmori t, saito a, taji s and hayashi r (1991), ‘Effects of high hydrostatic-pressure on characteristics of pork slurries and inactivation of microorganisms associated with meat and meat-products’, Int J Food Microbiol, 12, 207–216. sikes a l, tobin a b and tume r k (2009), ‘Use of high pressure to reduce cook loss and improve texture of low-salt beef sausage batters’, Innov Food Sci Emerg Technol, 10, 405–412. slongo a p, rosenthal a, quaresma camargo l m, deliza r, mathias s p and falcão de aragão g m (2009), ‘Modeling the growth of lactic acid bacteria in sliced ham processed by high hydrostatic pressure’, LWT – Food Sci Technol, 42, 303–306. solomon e b and hoover d g (2004), ‘Inactivation of Campylobacter jejuni by high hydrostatic pressure’, Lett Appl Microbiol, 38, 505–509. suzuki a, homma n, fukuda a, hirao k, uryu t and ikeuchi y (1994), ‘Effects of high-pressure treatment on the flavor-related components in meat’, Meat Sci, 37, 369–379. suzuki a, kim k, tanji h, nishiumi t and ikeuchi y (2006), ‘Application of high hydrostatic pressure to meat and meat processing’ in Nollet L M L and Toldrá F, Advanced Technologies for Meat Processing, Florida, CRC Press, pp. 193–217. suzuki t (1991), ‘Effect of pressure treatment on the muscle structure and heatinduced gelation of myofibril proteins’, in Hayashi R, High Pressure Science for Food, Kyoto, San-Ei Publishing Co, pp. 273–284 (in Japanese). suzuki t and macfarlane j j (1984), ‘Modification of the heat-setting characteristics of myosin by pressure treatment’, Meat Sci, 11, 263–274. tassou c c, galiatsatou p, samaras f j and mallidis c g (2007), ‘Inactivation kinetics of a piezotolerant Staphylococcus aureus isolated from high-pressure-treated sliced ham by high pressure in buffer and in a ham model system: evaluation in selective and non-selective medium’, Innov Food Sci Emerg Technol, 8, 478–484. torres j a and velazquez g (2005), ‘Commercial opportunities and research challenges in the high pressure processing of foods’, J Food Eng, 67, 95–112. trespalacios p and pla r (2007a), ‘Simultaneous application of transglutaminase and high pressure to improve functional properties of chicken meat gels’, Food Chem, 100, 264–272. trespalacios p and pla r (2007b), ‘Synergistic action of transglutaminase and high pressure on chicken meat and egg gels in absence of phosphates’, Food Chem, 104, 1718–1727. troy d j, crehan c, mullen a-m and desmond e (2001), High Pressure Technology in the Manufacture of Minimally-processed Meat Products, Dublin, Teagasc, Ireland (public domain document produced for the Irish food industry). tume r k, sikes a l and smith s b (2010), ‘Enriching M. sternomandibularis with alpha-tocopherol by dietary means does not protect against the lipid oxidation caused by high-pressure processing’, Meat Sci, 84, 66–70. vurma m, chung y k, shellhammer t h, turek e j and yousef a e (2006), ‘Use of phenolic compounds for sensitizing Listeria monocytogenes to high-pressure processing’, Int J Food Microbiol, 106, 263–269. wackerbarth h, kuhlmann u, tintchev f, heinz v and hildebrandt p (2009), ‘Structural changes of myoglobin in pressure-treated pork meat probed by resonance Raman spectroscopy’, Food Chem, 115, 1194–1198. wada s (1992), ‘Quality and lipid change of sardine meat by high-pressure treatment’, in Balny C, Hayashi R, Heremans K and Masson P, High Pressure and Biotechnology, Paris, Colloque INSERM/John Libbey Eurotec Ltd, vol. 224, pp. 253–258. yamamoto k, miura t and yasui t (1990), ‘Gelation of myosin filament under high hydrostatic pressure’, Food Structure, 9, 269–277.

© Woodhead Publishing Limited, 2011

616

Processed meats

yasui t, ishioroshi m and samejima k (1980), ‘Heat-induced gelation of myosin in the presence of actin’, J Food Biochem, 4, 61–78. yoshioka k, fukuchi n, tokifuji a, chisaka h and hachisuka k (2006), ‘The availability of high pressurized pork meat soft gel products for dysphagic diet’, Dysphagia, 21(4), 326 (Abstract). yuste j, capellas m, pla r, fung d y c and mor-mur m (2001), ‘High pressure processing for food safety and preservation: a review’, J Rapid Meth Aut Mic, 9, 1–10. zhao y, flores r a and olson d g (1998), ‘High hydrostatic pressure effects on rapid thawing of frozen beef’, J Food Sci, 63, 272–275. zipp a and kauzmann w (1973), ‘Pressure denaturation of metmyoglobin’, Biochemistry, 12, 4217–4228.

© Woodhead Publishing Limited, 2011

25 Effects of novel thermal processing technologies on the sensory quality of meat and meat products J. F. Kerry, Echo Ovens Ltd, Ireland

Abstract: The chapter discusses the general issues and challenges related to the cooking of meat products. An overview is given of the specific commercial thermal processing techniques currently employed for the preparation of readyto-eat (RTE) meat products. A general overview of the safety and organoleptic issues is finally presented as related to thermal processing of meats. Key words: thermal processing technologies, meat cooking, gelation, pasteurisation, safety.

25.1 Introduction The cooking of meat, as with dehydration, smoking, pickling, fermentation and salting, has long been recognised as a traditional form of food preparation and preservation. Thermal interventions during meat preparation were most likely adopted by our ancestors as a crude culinary technique for the enhancement of general meat palatability and flavour. Regardless, the process was clearly engaged and perfected long before any clear understanding of the underlying scientific (i.e. chemistry or safety) implications were elucidated. To illustrate this point of the ‘culinary art’ preceding the actual, ‘science’ let us consider food canning. In the late 1700s, industrialisation, together with a requirement by Napoleon’s armies for less dependence on local provisions, incentivised Nicholas Appert to realise the first generation of canning systems (employing glass containers). An Englishman, Peter Durand, improved this initial process and developed a method of sealing foods into unbreakable tin containers, later perfected by Bryan Dorkin and John Hall who established the first commercial canning factory in England in 1813. However, it was only later in 1864 that Louis Pasteur’s

© Woodhead Publishing Limited, 2011

618

Processed meats

groundbreaking scientific results and hypothesis on pasteurisation were finally accepted by the French Academy of Sciences. Furthermore, it was approximately 130 years after the first canning system was developed that the scientific calculations and product heat penetration curves (i.e. initial microbial contamination level calculations) required to determine minimum time–temperature combinations to achieve sterility in canning operations were finally reported. It is interesting to note that the fundamental principles of canning have not changed dramatically since Nicholas Appert and Peter Durand first developed and streamlined the process only the degree of automation and process control (Simpson et al., 2007). Cooking, regardless of methodology, generally requires a suitable thermal source with selected products being heated as a function of time in a suitable cooking medium (i.e. oil, moisture, air and/or combinations thereof). Moreover, cooking techniques may also vary based upon the meat species and cut, how this meat is pre-treated/seasoned, the mode and duration of heat application, as well as the degree of caramelisation/browning required. Effective pasteurisation/sterilisation while maintaining product wholesomeness are key quality cues and in culinary terms the following general categories of cooking may be described: • Steaming, simmering, poaching and cooking en papillote are referred to as moist-heat cooking (employing water or steam) and provide a fresh, aromatic, light, delicate taste, unique texture and colour to meats. Steaming is now considered a healthy, low fat option that amplifies the natural meat flavour of products. Poaching can be achieved in a small amount of liquid shallow poach or in a larger volume deep poach. In shallow poaching, the cook liquid/meat juices post cooking may be reduced and converted into a sauce complement. In a deep poach, the liquid (court bouillon) used is highly flavoured and typically not consumed; but rather acts as a processing aid, infusing a select balance of flavours into the finished product. En papillote cooking is a blend of shallow poaching and steaming. The product (usually fish) is cooked in a disposable package, such as a parchment envelope. A small amount of liquid is added to the package; then the product is seasoned, sealed in the package, cooked at a constant temperature, and served in the package. This technique is also employed in ‘sous vide’ cooking which is best described as a combination of vacuum packaging and controlled low temperature cooking. • Braising and stewing utilise varying levels of moist heat (i.e. stewing requires additional liquid unlike braising, etc.). Additional cooking times are usually employed to deliver acceptable meat tenderness where tougher cuts are used. The first step in a braised or stewed dish is to sear/ seal the meat with a small amount of fat in a heavy, shallow pan in order to generate a complex rich flavour and a deep colour (caramelisation). This next step is to cook this meat in a closed vessel, where the gentle

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

619

simmering creates steam and a consistent temperature for controlled, slow cooking. If a lighter colour is desired, sweating the mirepoix (mixture of onion, carrot and celery) by cooking it in a small amount of fat over low heat will add flavour without colour development. By comparison, deeply caramelising the mirepoix adds flavour, colour and aroma to the final dish. • Grilling, broiling and roasting techniques utilise a radient or dry heat source with fat being employed to add flavour or simply complement the cooking process (i.e. basting), rather than act as a cooking medium per se. Grilling is now being adopted by consumers as a ‘healthy’ low fat cooking option which allows excess fat to cook out of the product during heating. The rapid cooking technique is usually reserved for tender/ select meat cuts owing to the intensity of heat applied. Final cooked meats possess a caramelised exterior and moist interior with a savoury flavour profile. The process can also impart a smoky or charcoal endnote (i.e. flame grill), depending on the heating medium/fuel employed. Grilling can also physically mark the meat surface thus enhancing its visual appearance. • Sautéing, stir-frying, searing, pan-frying and deep-frying techniques utilise dry heat in combination with varying levels of fat and require a relatively short period of time. They provide a crispy exterior, a moist texture and savoury notes to final meats. Sautéing and stir-frying both employ a small amount of oil or fat in combination with a high heat for a short time. However, sautéing differs from stir-frying in that all the ingredients in the pan are cooked at once versus serially in a small pool of oil in the case of stir frying. Sautéing differs from searing in that searing effectively seals the surface of a larger piece of meat without fully cooking them through. Pan-frying and deep-frying are typically used in conjunction with coated or breaded products and provide multiple layers of textures and flavours. In deep-frying, products are completely immersed in oil or fat and cooked evenly on all surfaces. Pan-frying refers to meat cuts or large pieces that are cooked in oil that reaches only halfway up the side of the product which is flipped to cook both sides evenly. Sautéing differs from pan frying where sautéing refers to meat pieces or thinly sliced meats that are rapidly browned and cooked through on a high heat pan with a small volume of oil. A sauté pan must be large enough to hold all of the food in one layer, so that steam can escape – which keeps the ingredients from stewing, and promotes the development of ‘fond’ (a French culinary term to describe stock containing deglazed meat protein/ particulates). Once the meat protein is browned, the pan is deglazed with stock or water, removing all the ‘suc’ from the bottom of the pan). Most sauté pans are designed with heavy wide flat bases and shallow sides to maximise heat conduction. These pans provide optimal surface area contact with the low sides allowing for rapid evaporation and escape of steam during product heating.

© Woodhead Publishing Limited, 2011

620

Processed meats

• Retorting may be defined as an extension of moist heat cooking which is completed at pressures higher than atmospheric. Pressurised cooking reduces the boiling point of water which in turn is manifest as elevated cooking temperatures and reduced cooking times (Wang, 2006). This chapter will focus primarily on pasteurisation-type cooking systems employing atmospheric pressures. As cooking imparts unique flavours, colours and textures to meat it is critical for food product developers to understand these basic culinary techniques to successfully duplicate a chef’s signature dish on a commercial basis. The term culinology (as credited to Winston Riley, former president and a founder of the Research Chefs Association, RCA), is a term to describe and formalise the fusion of two disciplines namely, culinary art and food technology and has gained an increasing credence within the food industry in recent years (Brannan and Osborne 2004; Bissett et al., 2010). While a number of these cooking techniques as described may be considered impractical to replicate on a commercial scale, nevertheless a fundamental understanding of the ultimate organoleptic targets is required. Thus, sympathy for culinary – cooking – techniques can be successfully translated into novel processes and recipes (inclusive of novel adjuncts to deliver unique textures, colours and flavour profiles) to achieve this goal of signature dish replication on a commercial scale. Recent developments in processed meat manufacturing and in particular industrial-scale technologies for the effective delivery of ready-to-eat (RTE) cook – chill meat products with enhanced quality and safety have largely been driven by consumer demands for consistent premium quality convenience cuisines delivered ‘right first time’ at a competitive price. Advances in food technology/thermal processes to fill these basic consumer needs and wants have enabled companies to deliver traditional cooked meat products on a commercial scale, as well as invent new forms of RTE meat products and ingredients. Moreover, technical advances in RTE processing systems have also made it possible to ultimately store/display products on the shelf longer, ship them further from source, cook them faster, while maintaining/ enhancing their safety and wholesomeness (i.e. flavour, texture, colour, aroma and nutritional status, etc.).

25.2 Meat quality Effective monitoring of raw meat quality in terms of its intrinsic factors (e.g. animal – breed, sex, age – meat protein, water content, fat and connective tissue levels/type, salt soluble protein functionality, muscle fibre type, pH history, pale soft exudative/dry dark firm meat (PSE/DFD) considerations) and extrinsic factors (e.g. raw meat storage regimes/temperatures, hygiene/ microbial status, added ingredients, marinating/pH adjustments, mechanical

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

621

manipulation including particle size reduction, injection, massaging, forming, coating, slicing) as well as their interactive effects, are prerequisites to ultimate cooked meat quality. Although it may be difficult for meat processors to effectively monitor all of these factors, especially in the absence of vertically integrated operations, nevertheless their effective control can significantly influence ultimate cooked meat quality and consistency. It is possible to formulate recipes and employ added ingredients and/or physical treatments to compensate for poor quality meat; however, these interventions can never substitute for good quality fresh raw materials. Restructured or reformed meat products can vary greatly in their composition and mode of preparation. However, they may be broadly defined as those products which involve the assembly of individual meat pieces into a cohesive mass, which aims to simulate or retain some of the desirable properties of meat from high quality whole muscle cuts. The term ‘binding’ has been generally used to refer to the cohesion of water, fat and meat (Morrissey et al., 1987; Smith, 1991), with these functional properties being dependent, to a greater or lesser degree, on the formation of a heat-setting protein gel matrix during cooking (Zeigler and Foegeding, 1990; Xiong and Blanchard, 1994). Thus, adhesion of meat pieces is essential if the final product is to retain its structural integrity during subsequent handling and slicing post cooking (Schmidt and Trout, 1984; Asghar et al., 1985; Jolley and Sheard, 1990). The effects of salt, phosphate, cooking temperature and protein concentration have been determined on the ability of crude myosin to bind meat pieces (Xiong and Brekke, 1999; Smith and Acton, 2001). Salt and phosphate increases the ability of myosin to bind meat pieces by solubilising the salt soluble myofibrillar protein (MacFarlane et al., 1977; Brashear et al., 2002; Alvarado and Mckee, 2007). This allows for the molecular interactions necessary to produce a three-dimensional network of protein fibres to occur, resulting in myosin gels with greater strength and increased water-holding capacity. Several studies have reported that myosin forms an irreversible gel due to changes in its quaternary structure, which is heat initiated. The cohesive substance binding these muscle pieces together may be derived from non-meat additives, meat emulsions, or extraction of myofibrillar proteins (or meat exudate) solubilised from the chunks or pieces themselves (Schmidt and Trout, 1984; Pearson and Gillett, 1996; Kerry et al., 1999a) as illustrated in Fig. 25.1. The interest in restructuring and reforming techniques has contributed to numerous reviews on the subject (Pearson and Tauber, 1984; Jolley and Purslow, 1988). Manufacturing techniques employed during the production of the majority of these reformed/comminuted products are largely empirical with process development and product formulation based traditionally upon trial and error methodology rather than sound scientific principles. Thus, ultimate product quality has been largely governed by a complex series of interactions between individual unit operations and raw materials used (Jolley and Sheard, 1990).

© Woodhead Publishing Limited, 2011

622

Processed meats Polysaccharide Connective tissue

Striated muscle

Protein    Salt

+   O H H  +  R 

Film  Lipid 

s 

s  O  +  H  + H  R 

Encapsulated fat droplet

Hydrated protein

Water molecules

Fig. 25.1 Illustration of the principal components of a typical meat batter or exudates and functional properties of salt soluble proteins, namely water, fat and protein binding.

Comminuted meat products including frankfurters, bologna and meat loaves may be described as multi-phase systems consisting of solubilised muscle proteins, muscle fibres, fat cells, fat droplets, water, salt and other ingredients (Gordon and Barbut, 1990). Two theories have been proposed to explain fat stabilisation within these meat batters. The emulsification theory, attributes fat stabilisation to the formation of an interfacial protein film around the individual fat globules. The physical entrapment theory, however, proposes that fat particles in meat batters are physically entrapped within a highly viscous protein solution prior to heating and then stabilised within a gel protein matrix after thermal processing. The relative contribution of each effect towards meat batter stabilisation depends upon environmental conditions, the physical state and properties of the lean phases, processing conditions and the characteristics of the product being manufactured. In addition, it is generally recognised that the formation of a protein gel matrix by myofibrillar proteins during thermal processing is largely responsible for the water entrapment within these products (Lee et al., 1981; Gordon and Barbut, 1992). Addition of alternative ingredients such as non-meat proteins and polysaccharides may similarly enhance cook yields, texture and water-holding capacity of meat products (Offer and Knight, 1988; Ledward, 1994), as well as meat bind (Kerry et al., 1999b). However, recent EU legislation amendments regarding food labelling requirements for allergens (European

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

623

Union, 2003) have resulted in a demand for prepared meat products possessing clean ingredient listings (i.e. free from cow’s milk, fruits, legumes – especially peanuts and soybeans, eggs, crustaceans, tree nuts, fish, vegetables, celery – and other foods of the Umbelliferae family, wheat and other cereals). This labelling amendment has generated a significant challenge for meat processors to source and replace a wide range of functional non-meat proteins (i.e. soya, wheat and dairy proteins), as well as chemically modified starches with ‘natural’ functional allergen-free alternatives which afford a clean listing in final RTE meats. Similarly, the demand for salt (i.e. sodium, phosphate and nitrite) reductions in processed meat products has challenged processors to revise/optimise existing product recipes. Changes in the meat protein : water ratio, as well as fat and carbohydrate levels added to meat systems, will clearly influence cooked meat quality, texture and colour development. Thus, the influence of recipe reformulation in tandem with cooking protocols should be carefully considered based on potential changes in the physicochemical interactions and behaviour of these alternative ingredients within meat products during thermal processing.

25.3 Thermal processing 25.3.1 Fundamentals of cooking Regardless of product type and formulation, the effects of thermal processing on meat are manifest as follows: • Physical alteration of meat texture through the solubilisation of collagen proteins to gelatine. Aggressive (high temperature – short time) cooking of meat cuts derived from older animals and/or containing elevated levels of connective tissue can lead to decreased meat palatability (shrinkage) in the absence of suitable physical manipulation (mincing, chopping, needle/blade tenderisation, enzymatic interventions and/or combinations thereof). • Physical alteration of meat product shape and homogeneity through the gelation of salt soluble meat proteins in prepared meats allowing for the effective binding of meat pieces water and fat. • Generation of unique cooked meat flavours and appearance (i.e. browning, bar marking/grilling, searing, frying and curing applications). • Enhanced shelf-life stability through the deactivation of meat enzymes and other reactive substances. • Shelf-life extension and enhanced safety in cooked meats through controlled cooking regimes (i.e. pasteurisation-sterilisation as a time– temperature function). Reduction of initial bacterial loads and a similar decrease in water activity (Aw) especially on external cooked meat surfaces, retards potential product spoilage. Ultimate shelf-life and product safety are influenced by handling and storage methods employed preand post-cooking.

© Woodhead Publishing Limited, 2011

624

Processed meats

25.3.2 Thermodynamics During conventional cooking one is usually attempting to bring the food or meat product and heating source into thermal equilibrium. When we discuss temperature of food, we are referring to a measure of how hot the product is relative to the boiling (100 °C) and freezing (0 °C) points of water (at atmospheric pressure). Heat transfer mechanisms employed within cooking systems for the production of pasteurised or sterilised foods, although complex, are generally defined in terms of conduction (heat transfer in a solid phase), convection (heat transfer in a liquid phase) and radiation (heat transfer via electromagnetic waves). Thermal processing of meat can be essentially classified as either wet (i.e. oil, water immersion, steaming) or dry (i.e. hot air or infrared flash roasting) cooking. Regardless of mode, traditional convection/conduction heat transfer during cooking relates to the temperature difference between the food surface and its surrounding environment and the thermal conductivity of these surroundings. The efficiency of heat transfer and control is a fundamental criterion in conventional oven design (Chang et al., 1998; Diéguez et al., 2010). The ability to integrate such model predictions into the automation function tools of commercial steam ovens (i.e. product-driven pasteurisation programming) to accurately compute cooking protocols is a practical example of using such systems (Bottani and Volpi, 2009). Numerous studies have been conducted on the cooking and roasting of meats. However, it is impossible to accurately predict the precise effects of individual cooking conditions, and/or raw meat composition on final cooked product organoleptic, nutritional and microbiological properties. During meat grilling and roasting, heat transfer is rapid and physical stresses due to protein denaturation/contraction can further impact considerably on ultimate mass transfer predictions (Nicolaï et al., 2001; Cheng and Sun, 2008). Thus, the challenge is to precisely describe the different boundary conditions especially product evaporation, and water migration within the meat (Huang and Mittal, 1995). For example, recorded meat surface, ‘skin’ temperatures of thermally processed products can exceed 160 °C while core temperatures can be as low as 50 °C. Similarly, mass transfer calculations should be factored for the three phases: solid, liquid and vapour as well as a calculation of the swelling/contraction effect on the product (Fowler and Bejan, 1991). The application of excessive intense dry heat onto the surfaces of large, raw whole muscles can lead to a very aggressive searing/sealing of the meats surface (or case hardening), manifest as extended cooking times, reduced yields and palatability. In certain instances this type of sealing can be desirable dependent upon the meat product and degree of searing. Cooking dwell times for low temperature (below 0 °C) comminuted/restructured products are similarly extended due to the state of the water phase and the additional energy required to bring meat products through latent and uneven cooking if the temperature variation is large. Aggressive heating of such tempered restructured and formed meat products (below 0 °C) can result in ‘thermal

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

625

shock’ manifest as physical deformation or shattering of products (especially comminuted/restructured meats) during the cooking process.

25.3.3 Predictive modelling Owing to the complexity of oven systems, where heat distribution and flow patterns are dependent upon such a large number of thermodynamic variables, simulation-based design affords process/equipment designers the possibility to carefully refine optimal combinations of food and process parameters (i.e. heating sources, circulation system design, etc.) for specific meat applications in an efficient manner while reducing some of the potential time and expense experienced in prototype building (Norton and Sun, 2006). Practical use of simulation-based design techniques can drastically reduce the number of experiments necessary to predict the location of product and process cold spots (or thermal centres) in tandem with the shortest residence times spent within the heating system/holding zone. Thus time–temperature history at these locations can be employed to theoretically generate effective pasteurisation/sterilisation protocols (Cox and Fryer, 2002; Heldman and Newsome, 2003). Radiation heating profiles, being more complex than those generated from conventional conduction/ convection heating techniques, require more elaborate model designs. Regardless, 3D computer models have been successfully employed in electromagnetic heating studies and potential heat transfer patterns calculated for a number of foods. These studies have provided a comprehensive insight into radiation heating processes by revealing interior power absorption effects which are difficult to elucidate with experimentation data alone (Dibben, 2000; Zhang and Datta, 2000). Time–temperature history at the coldest point determines the microbiological safety which is generally predictable for pure solid or liquid foods (Van Loey et al., 1995; Sastry and Cornelius, 2002). For example, the cold spot in a conduction-heated (solid) food is usually defined as the geometric centre (Lee et al., 2007). Once temperature is determined at the coldest point (as a function of time) accumulated lethality can be calculated (Saltiel and Datta, 1998; Datta et al., 2005; Gaze, 2005). Listeria monocytogenes is regarded as the most heat resistant, non spore forming foodborne pathogen. Based on this fact, it is inferred that other non-spore forming vegetative pathogens such as Salmonella serova’s, Staphylococcus aureus, Yersinia enterocolitica, Vibrio parahaemolyticus and Escherichia coli O157 : H7 that may be present in products should also be destroyed by a 6-D heat process (Murphy et al., 1999; FSAI, 2006). The Stumbo equation may be employed to calculate a 6-D reduction in L. monocytogenes (Stumbo, 1973): F = Dr log10 n

25.1

Where F = required process lethality; Dr = D-value at the reference temperature and n = required decimal reduction.

© Woodhead Publishing Limited, 2011

626

Processed meats

In order to achieve a 6-D reduction of L. monocytogenes numbers a reference time and temperature combination of 70 °C for 2 min, with a z-value of 7.5 celsius degrees (C°) is recommended (FSAI, 2006). Equivalent time – temperature combinations to this reference temperature (Equation 25.1) can then be determined using the lethal rates equation (Equation 25.2): L = 10T−Tx/Z

25.2

where: L = lethal rate, T = target temperature (°C), Tx = reference temperature (°C) and z = z-value (C°). Recommended time–temperature combinations (employing Equation 25.2) are outlined in Table 25.1. It is important to note that final core temperature – dwell time/holding regimes may be influenced by the product type, cooking systems and precision of instrumentation (temperature detection) systems employed. The test uncertainty ratio (or deviation about the mean) must therefore be duly considered on a product by product basis (Hendrickx et al., 1995; Heldman and Newsome, 2003; FSAI, 2006). Further controls may be necessary where risk assessment indicates that the growth and toxin production of Clostridium botulinum or other sporeforming bacteria is a particular risk (Betts, 1996). Intrinsic controlling factors which prevent the outgrowth of spores and toxin production by non-proteolytic strains of Cl. botulinum include: • A pH of less than 4.5 throughout the food. • Addition of preservatives such nitrites and/or nitrates or NaCL salts (NaCL levels of 3.5% aqueous) throughout the food.

Table 25.1 Example of equivalent time–temperature combinations to achieve a 6-D reduction in L. monocytogenesa Temperature (°C)

Time

64 65 66 67 68 69

12 min 37 s 9 min 17 s 6 min 50 s 5 min 3 min 42 s 2 min 43 s

Temperature (°C) 70b 71 72 73 74 75

Time 2 min 1 min 28 s 1 min 5 s 48 s 35 s 26 sc

Assuming a linear z-value = 7.5 C° with a reference temperature of 70 °C. The interaction between foods intrinsic and extrinsic properties may alter these equivalent lethal rates and as such values must only be used as an indication of the lethal effect of the heat process on L. monocytogenes. b Recommended by the FSAI as the reference temperature and time required for a 6-D reduction in numbers of L. monocytogenes. c With such short times above the reference temperature of 70 °C, it is assumed that when 75 °C is reached, the equivalent process to 70 °C for 2 minutes has been achieved. Source: FSAI (2006). a

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

627

• Water activity (Aw) of 0.97 or less throughout the food. • Any combination of heat processing and preservative factors, shown to prevent or eliminate outgrowth and toxin production by Cl. botulinum. Non-proteolytic Cl. botulinum Type B is regarded as the most heat-resistant form of non-proteolytic Cl. botulinum. Therefore, all non-spore-forming vegetative pathogens including L. monocytogenes that may be potentially present in the food should also be eliminated or reduced to safe levels by this 6–D heating process. A reference time and temperature combination of 90 °C for 10 min, with a z-value of 10C° has been suggested to achieve a 6–D reduction in numbers of psychrotrophic (non-proteolytic) Cl. botulinum Type B (i.e. sterilisation effect). Equivalent time and temperature combinations (using Equation 25.2) are presented in Table 25.2 as an example of the necessary process to achieve a 6-D reduction in numbers of psychrotrophic Cl. botulinum Type B in foods (Betts, 1996; FSAI, 2006). Identification of a product’s coldest point during radiative heating is less straightforward and can shift during the heating process, depending on a number of food and oven factors (Fleischman, 1996; Zhang et al., 2001). It is very difficult to precisely compare the effectiveness of microwave heating to conventional heating based on the literature because of the different techniques employed or the lack of detail in the methods or materials used, especially in relation to temperature monitoring (Heddleson and Doores, 1994). A recurring conclusion in the literature is that non-uniform heating by microwaves may lead to survival of foodborne pathogens. For example, studies have demonstrated that the measured internal temperature of poultry test products did not accurately reflect the lower levels of inactivation of surface-inoculated Salmonella due to lower temperatures realised at the product surface (Schnepf and Barbeau, 1989).

Table 25.2 Example of equivalent time–temperature combinations to achieve a 6-D reduction in psychrotrophic Cl. botulinum type ba Temperature (°C) 80 82 84 86 88 90

Time (min) 100 63 40 25 16 10

Temperature (°C) 92 94 96 98 99 100

Time (min) 6.3 4.0 2.5 1.6 1.3 1.0

Assuming a linear z-value = 10 C° with a reference temperature of 90 °C. The interaction between foods intrinsic and extrinsic properties may alter these equivalent lethal rates and as such, values must only be used as an indication of the lethal effect of the heat process on psychrotrophic Cl. botulinum Type B. Source: FSAI (2006).

a

© Woodhead Publishing Limited, 2011

628

Processed meats

Regardless, the scope of any predictive model on food safety is to effectively assess theoretically generated outcomes against (or in tandem with) applied laboratory studies and more importantly their validation against pilot-scale cooked meat data. The latter commercial validation technique is usually achieved via the inoculation of meats with selected bacterial strains; however, this is clearly a food safety processing challenge and such controlled trials are difficult to complete on a pilot scale owing to potential crosscontamination risks as well as adequate access to ‘available’ processing time. Preservation techniques currently act in one of three ways: (1) preventing pathogen access to foods, (2) inactivating them should they gain access or (3) preventing or slowing their growth should the previous two methods fail (Gould, 2000). While the ‘safe harbour’ guidelines (i.e. specified time– temperature combinations) for pasteurisation of RTE meats remain in place, US regulatory changes are shifting the onus on processors to ensure, through scientific rationale, that a new or modified RTE thermal process meets lethality performance standards. US Regulations state that any new process for RTE, whole-muscle products must achieve 6.5 log10 or 7.0 log10 reduction in Salmonella for whole-muscle beef or poultry, respectively (USDA-FSIS, 1999). Processors are no longer being held to specific endpoint temperatures when developing novel processes or niche cooked products rather, they, ‘must validate new or altered process schedules by scientifically supportable means’ (USDA-FSIS, 2002). Nevertheless, requirements for traditional cooked meats (and in particular imported cooked products) are well documented (USDA-FSIS, 2006). Moreover, any food product that is commercially sterilised within the United States requires that the sterilisation process be filed with the Food and Drug Administration (FDA). A process filing is a document which describes details of the sterilisation process (such as mathematical models, experimental data, microbiological verification data, etc) which shows that the processor fully understands the sterilisation process and is completely aware of the worst case scenario (Larkin and Spinak, 1996). The challenge arises that while product and process parameters are known to affect thermal resistance of bacteria, information reported is largely generated from laboratory studies that encompass a limited range of conditions and scenarios (Orta-Ramirez et al., 2005). Nevertheless, kinetics-based models to determine lethal death times for pathogenic bacteria and microbiologically safe processes have the potential to provide food processors with a greater understanding in pasteurisation and sterilisation requirements (Marcotte et al., 2008).

25.4 Thermal processing methods Industrial-scale food processing apparatus for the effective thermal treatment (pasteurisation or sterilisation) of meat and other food products may be classified as follows:

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

629

• conduction-based systems • heated belt–direct contact cooking systems • convection-based systems • free air convection • forced air convection • impingement • water immersion systems • ‘sous vide’ cooking • oil frying • radiation-based systems • infrared • microwave • radio frequency • ohmic heating • hybrid systems.

25.4.1 Conduction-based systems Heated belt-direct contact cooking systems This form of heating takes place when two bodies are in direct physical contact with one another, for example, the cooking of a meat patty on a hot plate. As the plate is set at a higher temperature than the product, the motion of the molecules in the hotter body will vibrate the molecules at the point of contact with the cooler body, resulting in a temperature rise. The amount of heat transferred through conduction is dependent upon the temperature differential between the bodies, meat product composition, thickness of the product, the surface contact area (product geometry), degree of doneness, as well as the duration of the heat transfer (Wichchukit et al., 2001; Zorrilla et al., 2003). Units (SI) for conductivity are the watt per square metre (W/m2), watt (W) and kilowatt (kW). Good conductors of heat are typically dense substances as they have molecules packed close together which allows the molecular agitation process to permeate the substance easily. Thus, metals are good conductors of heat, inversely gaseous substance, having low densities or widely spaced molecules are poor conductors (or insulators). The measure of the ability of a substance to insulate is its thermal resistance, commonly referred to as the R-value (RSI in metric). Industrial direct contact continuous cooking systems employ either bottom or bottom/top heated belt configurations. Belts are usually 600– 1000 mm wide, thin and non-stick in design, employing TeflonTM impregnated on a fibre glass or similar weave which allows for efficient heat transfer (from the heat source) while the non-stick properties of the TeflonTM prevents raw meat products adhering to the heated belt. The TeflonTM conveyor type belts are designed to travel under tension over the bottom (or top) heated bed (i.e. heated plate or bed). Belt tracking is an important

© Woodhead Publishing Limited, 2011

630

Processed meats

design consideration with a wide range of tracking options available. Poor tracking leads to potential belt damage, resulting in more frequent belt replacements. An adjustable upper heated belt assembly is an optional design to provide dual (top and bottom) contact heating. The upper belt is usually adjustable in order to match product profiles/heights and optimise belt surface contact. Bottom-heated contact belt cooking systems are also available with additional steam sparging systems to improve heat transfer and cooking performance. Contact units are supplied as either compact conveyor units or as larger enclosed installations (especially where sparge steam is used). These enclosed units employ forced convection heating and air recycling systems to increase heat transfers and energy efficiencies. Contact cooking units are more effective for small uniform component meat products (i.e. beef patties, bacon, chicken portions) where heat can be transferred quickly and efficiently and surface contact is optimal. The systems are less effective on larger non-uniform geometry products. Contact belts are usually of light construction (to optimise heat transfer) and can damage easily, compromising belt longevity. Similarly, the cooking of high fat content products (i.e. bacon) can significantly reduce belt quality due to the corrosive nature of the hot fat in combination with salts.

25.4.2 Convection-based systems Free air convection Convection involves the movement of a heated fluid (i.e. gas or liquid) from the primary heating source (heating elements, heat exchange coils, etc.) to the food. Convection maintains a higher temperature at the food surface via effective recirculation of the surrounding fluid environment towards the foods while simultaneously transporting cooler fluid away (i.e. recirculation). Thus, effective cooking of the food is achieved as the fast moving molecules of the energised convection medium collide with the slower/ static molecules in the (lower temperature) food (Singh et al., 1984; Obuz et al., 2002). The higher the heat capacity and heat conductivity, the higher the heat flux and faster the cooking rate. Metric units (SI) of measure for convective heat transfer rates are the watt (W) and kilowatt (kW). Convection is dependent upon the thermal properties of the fluid as well as surface conditions at the body and other factors that affect the ability of the fluid to flow. With a low conductivity fluid such as air, a rough surface can trap or impede air flow, reducing conductive heat transfer and consequently can impact upon convective currents and ultimate product cooking (Ghisalberti and Kondjoyan, 1999). Thus oven circulation patterns and heat transfer systems must be carefully devised (Murphy et al., 2001). Two types of convection, Free (or natural) and forced air systems, are available. Traditional bake/stove ovens were designed as inert heating boxes employing indirect solid fuel as a heating source. These free convection units were later fitted with electrical elements or gas burners as alternative

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

631

energy sources. Natural convection ovens employ fluid (usually air and product moisture released during cooking) heated through direct contact (conduction) with the heated walls of the oven. As this fluid heats, it expands, becomes less dense and consequently rises (excitation of fluid molecules). This initiates a random fluid motion process in which the current of heated air circulates past the colder static meat products, heating their outer surfaces. The colder air is randomly re-energised by the oven’s heated walls and the heat transfer process continues until the meat product is cooked (or thermal equilibrium is achieved between the heating source and the meat product, etc.). Forced air convection Forced air convection ovens subsequently evolved (Fig. 25.2), removing the randomness of air distribution/circulation of traditional systems. As the term suggests, air velocity is controlled within these ovens using circulation fans, or alternative circulation systems which can significantly impact on ultimate mass heat transfer rates within final products (Skjöldebrand, 1980; Holtz and Skjöldebrand, 1986). Forced convection systems have now become the design of choice in most industrial-scale convection ovens. Optimisation of these systems has focused primarily on fluid flow (circulation) around food products and optimisation of heat transfer within the fluid stream. Dynamic fan configurations (using centrifugal, forward curve, paddle fan options, etc.), heat exchange systems (e.g. thermal oil, natural or propane gas-fired burners – direct fire/indirect fire systems – or electric coil types) have similarly been developed for these systems (Navaneethakrishnan et al., 2010). Although direct gas fire systems are more energy efficient their principal disadvantages include potential gas emissions (NOx and CO) in the working environment (in the absence of adequate ventilation) which are dependent on the oven/burner configuration, as well as potential surface colour defects (pinking) in final meat products due to reactions with nitric oxide/combustion gas residues (Cornforth et al., 1998). Chemical impurities (e.g. boiler salts, water impurities) within steam lines can similarly lead to potential colour defects on exposed flesh during steam heating. Other factors associated with pinking have been related to the presence of the different meat pigment classes, such as undenatured myoglobin and oxymyoglobin, reduced ferrohaemochromes, nitrosyl haemochromes, carbon monoxide haemochromes, and cytochrome c. The formation and chemical reactivity of these pigments are directly related to the in situ conditions that are represented by pH, redox potential, degree of denaturation and presence of reacting ligands (Holownia et al., 2003). Commercial forced air convection ovens are usually fitted with steamgenerating systems (direct steam injection, or indirect water atomisation onto heating coils, etc.) and/or wood smoking generators (liquid (atomisation), friction or wood chip options) as standard. The configuration of fans

© Woodhead Publishing Limited, 2011

632

Processed meats

12 

               11  10   9

8 7 6 5 4 3 2 1

Fig. 25.2 Image of static roll on, roll off oven system with microprocessor controls. 1. Access via stainless steel double doors with appropriate high temperature gasket seals. Doors usually fitted on high and low care sections of the oven to allow for efficient (and safe) conveyance of cooked products post heating into high care. 2. Ovens are usually designed as strong structural stainless steel frameworks with appropriate lifting points. Thermal processing apparatus within the EU are typically sold with CE mark/certification and compliant with machinery Directives (European Union, 1989, 2006), as well as adhering to general food hygiene requirements. 3. Air circulation control via baffles/dampers ensures optimal air distribution throughout the oven chamber. Air vents usually designed to align with individual trolley tiers thus ensuring optimal air circulation over food products. 4. Oven walls are usually made of stainless steel, double walled (or skinned) construct, employing inner insulated panels to optimise heating efficiencies and oven safety. 5. Air probes (wet and dry temperature probes) are fitted as standard to determine real time chamber air temperature and humidity. Alternatively, humidity sensors may also be fitted as alternative direct detection system in tandem with air temperature probes. Additional temperature probes are also installed to detect product core temperatures. Thus cooking regimes for individual meat products may be pre-programmed as a function of time or against ultimate product core temperatures.

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

633

Fig. 25.2 Continued 6. Oven control panels usually contain automation systems to monitor: temperature controllers (PID control of combustion systems), air temperature (wet and dry) probes to monitor/control environmental conditions, controllers/inverters for fan speed adjustment, damper adjustment systems, as well as steam/moisture delivery controllers. All functions are generally controlled via a basic microprocessor or programmable logic controller (PLC) system. These automation systems may be supplied as either: manual, semi automatic or ‘recipe-driven’ options. Control panels may also operate integrated oven smoke generating units and/or refrigeration systems. 7. Integrated cleaning in place (CIP) systems usually fitted as standard with adequate drainage points fitted within the oven floor space. 8. Heating/combustion systems are usually roof mounted. Combustion systems are normally indirect, utilising natural gas, liquid propane gas (LPG), electric coils, thermal oil as fuel sources. 9. Air circulation/distribution control dampers may also be employed in conjunction with ducting systems in order to further manipulate air circulation within the oven chamber. Additional vents may also be fitted to draw fresh air into the oven cell where drying/fermentation processes are considered. 10. Humidity control (generation) is usually achieved via sparge steam or hot water injection directly into the oven-heated airstream. 11. Air circulation (radial) fans employed to generate even air distribution and temperature uniformity. 12. Independent interlocked exhaust fan systems fitted to the combustion systems to safely vent combustion gases to atmosphere.

and heating sources within these ovens in combination with air diversion techniques (i.e. side wall baffles, tubes, oscillatory circulation fans (in larger ovens), as well as rotating trolleys to improve air circulation). In some instances, air circulation can be controlled and optimised through the use of automated dampers (Fig. 25.3).

Fig. 25.3 Example of typical airflows within a static (box) oven system employing damper systems to effectively direct and optimise air circulation within the main cooking chamber.

© Woodhead Publishing Limited, 2011

634

Processed meats

Forced convection oven systems are usually designed as batch (roll on/ off trolley systems) with meat products pasteurised in batch or batchcontinuous formats, or as continuous rail type systems. It is quite difficult to achieve optimal heat distribution within these systems because of their configuration and the fact that air speeds are significantly reduced as air is passed through/across the trolley tiers. This reduces heat transfer efficiencies and the quality of roasting/baking operations. However, forced convection systems are quite effective in the cooking of larger geometry products where steam cooking is employed. As a general rule, product geometry (>150 mm in height) and/or weights greater than 1.5 kg (i.e. large beef roasts, whole hams, etc.) are more suitable for batch cooking processes based on the cooking dwell times required for successful pasteurisation of such products. In typical batch ovens, temperature probes are physically inserted into food products at the defined cold spot (or thermal centre). The largest product – where geometries are non-uniform – is usually probed and placed in the ovens thermal centre (e.g. centre rack/tray of the central trolley etc). Oven heating profiles are usually supplied through manufacturers or generated from oven temperature mapping programmes incorporated as part of an overall HACCP (hazard analysis of critical control points) programme (European Union, 2004). Product pasteurisation is usually achieved as a function of either set time or target core temperature which is pre-programmed on the oven’s controller/microprocessor. When the product has achieved target core temperature/time, the oven sounds an alarm or cycles down automatically. Cooked product is cooled within the oven chamber (using water shower or refrigerated air options) and/or transferred to a blast chilling room. It is important to note that pasteurisation encompasses both heating and cooling regimes (as a function of time × temperature for each hurdle) and this is fundamental to any cooking application. Rapid chilling in tandem with an efficient heating protocol ensures an optimal bactericidal (pasteurisation) effect by increasing the combined effectiveness of the hurdles. Impingement cooking The scale and speed of product preparation in modern food processing have generated an increased demand for continuous rapid processing of foods in applications such as thawing, roasting, baking (as well as cooling/freezing). Perhaps one of the most exciting developments in recent years is that of the continuous air impingement oven, generally defined as an advanced convection system whereby jets of heated or chilled fluid are addressed at high velocities (approx 10 to 50 m/s) onto the surfaces of a food or meat product. The use of high air speeds effectively removes the product boundary layer resulting in increased rates of heat transfer (Ovadia and Walker, 1998) as outlined in Fig. 25.4. The meat industry has successfully employed impingement as an advanced thermal processing system with the ability to reduce cooking

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

635

Plenum tube configuration

Upper plenum box

Columinated high velocity air stream

Upper tubes

Boundary layer Product

Product

Product

Lower tubes

Conveyor belt

Lower plenum box

Fig. 25.4 Detail of top and bottom impingement jet tube array illustrating collimated air movement over the product.

Fig. 25.5 Layout of a typical ECHO continuous impingement pasteurisation (heating and cooling) line

times within food products. One of the first impingement ovens introduced for use in RTE meat applications was that of the ECHO impingement oven system. As impingement technology is quite versatile, it can be adopted for a wide range of processes such as tempering, steaming, baking, drying, and chilling (Fig. 25.5).

© Woodhead Publishing Limited, 2011

636

Processed meats

In some instances, faster heating operations improve the overall quality, yield and wholesomeness of food products through enhanced moisture retention (Wahlby et al., 2000). One key benefit of impingement cooking is that of its ability to efficiently and uniformly roast/brown meats and other foods which is difficult to successfully achieve in the majority of cooking systems (i.e. non-load-related cooking). The complex mechanisms of nonenzymatic browning and the Maillard reaction are achieved via interactions between amino acids, peptide and/or protein with sugars and/or ascorbic acid and initiated in the presence of elevated surface temperatures (Leedl and Schleichere, 1990). The Maillard reaction can be increased through the addition of a reducing sugar (glucose, fructose, lactose, etc.), increasing the meat pH, or increasing the temperature. Even small increases in pH, greatly increases the Maillard reaction rate and results in sweeter, nuttier and more roasted-meat-like aromas (Meynier and Mottram, 1995). Addition of glucose (e.g. corn syrup) at a low level has been shown to increase the Maillard reaction and improve the flavour profile (Meinert et al., 2009). The Maillard reaction occurs noticeably around 130 °C (265 °F); however, it only produces a boiled/poached versus roasted aroma at this temperature. Effective browning and roast flavour development are achieved at temperatures around 150 °C (300 °F) with the addition of glucose (Skog, 1993). Although higher temperatures significantly increase the rate of the Maillard reaction, prolonged heating at over 175 °C (350 °F) can significantly increase the probability for the development of mutagens and toxic compounds. Principal components within the impingement system include the plenum (air box), its ventilation configuration/exhaust mechanisms, as well as the heating system employed (direct or indirect heating systems). The majority of industrial cooking systems employ impinging jets where a jet of liquid or gas generated from a nozzle is directed onto a desired surface (as opposed to free jets that do not have a target surface per se). Impingement jets are further classified as either confined or unconfined with actual airflows determined based on Reynolds number where values less than 3000 equate to a laminar flow and greater than 3000 a turbulent flow. Air exit from a slot or tube is categorised as the potential core region, developing flow region, and enveloped flow region. The potential core region is the part of the flow where there is no vorticity in the jet. Vorticity is introduced within the flow because of the free shear between the impinging jet and the stagnant air. As a result, the jet tends to become turbulent, and the potential core is eroded. The turbulence level increases along the length if the flow and the peak turbulence shift towards the jet centreline. The rate of energy dissipation and the length of the potential core are largely dependent upon the shape of the nozzle, exit velocity of impinging fluid, length of nozzle and sharpness at nozzle exit (Polat, 1993; Sarkar et al., 2004). Adjustment of the plenum height (and tube distance from the product surface) clearly impacts on impingement efficiency.

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

637

During impingement, air is usually drawn through the circulation system (fans), suitably heated as it is forced into the upper (tube–plate) or upper and lower (tube–tube) plenum chambers, channelled via a series of slots, diffuser trays (with or without nozzles or jets) onto the food surface, with exhaust air quickly evacuated away from the product and recycled. Various slot shapes and impingement nozzle (i.e. ‘short’, orifice type, or ‘long’, finger type) arrays (i.e. uniform or staggered tube patterns), employed in various cooking systems clearly impact on air velocity/balance and must be calculated during the design stages to ensure optimal heat transfer as a function of cooking dwell time (Angioletti et al., 2003). Circulation fan design in relation to plenum box volume and geometry must also be calculated and sized to ensure uniform air velocities across the product bed and efficient recovery of exhaust air. Travelling belt widths of up to 2.5 m wide are feasible; however widths ranging from 600 to 1000 mm are more common within the meat industry (Fig. 25.6). Similarly, accurate plenum height adjustment ensures optimal heat transfer via removal of the products ‘boundary layer’.

Fig. 25.6 An ECHO impingement oven installation.

© Woodhead Publishing Limited, 2011

638

Processed meats

While the use of impingement as a cooking technique has gained popularity within the meat industry there is a poor understanding of the inherent transport phenomena associated with such systems. This includes measurement and prediction of heat and mass-transfer rates for multiple impingement jets, the interaction of the jet flow patterns with the product (depending on its geometry and surface roughness), the effect of non-uniform heating or cooling of the product due to spatial variation of heat transfer coefficients, and developing optimal parameters for equipment design (Nitin and Karwe, 2004; Cronin et al., 2008). Therefore, impingement cooking protocols must be carefully considered for individual meat applications due to its aggressive nature. Ratios of active (impingement) : passive (relaxation/non impingement) heating steps and related dwell times must be calculated during the oven design stage as these ratios can vary dependent upon the meat: type/application, composition and geometry. Absence of suitable tempering and equilibration steps pre and post-impingement will also have a potential negative effect on product heat transfer rates (i.e. case hardening), meat quality (i.e. thermal shock, product deformation) and reduced cooking yields (due to extended cooking times). Water immersion systems Water immersion has been employed as an effective energy efficient cooking process within the meat industry for a considerable period of time. These systems are usually batch continuous operations; however, a number of novel continuous basket or thermal screw units have been developed in recent years for the cooking of smaller component products. Cooking in water is quite an efficient heat mass transfer process where browning and roasting of final meats is not required. The system is particularly suitable to pasteurisation of large geometry products (hams, meat logs, etc.) with products usually being cooked in suitable water-impermeable packaging. Cheng et al. (2005) compared ham cooking in water immersion (at 82 °C) versus air cooking (at 82 and 120 °C) and demonstrated that water cooking in low medium temperatures could achieve higher cooking efficiencies (i.e. product yields) and compatible nutritional and textural results compared with controls. Moreover, shelf-life studies showed that microbial loads after 21 days were lower than control values. One key commercial consideration in immersion cooking is that of water quality during the process. As moderate heating temperatures are employed (usually 75–85 °C), potential microbial and cross-contamination issues cannot be ignored. This is particularly true in the event of damaged packaging (i.e. leakers). In an attempt to address this issue, commercial systems are fitted with suitable water purification systems including clarification and solids/fines removal, UV treatments, ozone sparging. In addition, water heating systems may be utilised to reduce potential microbial contamination of water and increase heat transfer efficiencies. Pasteurisation is

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

639

achieved using in-line plate heat exchangers, steam injection – regeneration systems and/or heat circulation units. Tank design usually encompasses, water circulation/flow characteristics, jacketing or lagging walls, drainage and cleaning issues as well as product loading/distribution. Cooking in batch processes is usually achieved through a gradual heating profile (similar to delta cooking). Continuous cooking systems may also employ counter-flow heating where products exiting the system are addressed with the hottest (in-feed) process water. ‘Sous vide’ cooking The French term sous vide is translated as ‘under vacuum’ and as the term suggests is a cooking technique where meat products are heated under vacuum within sealed plastic pouches at low temperatures for long dwell times. Processing meat products at low (<100 °C) temperatures and subsequent rapid chilling and storage under refrigerated conditions (0–3 °C) is considered to offer enhanced product quality and extended shelf-life (Church and Parsons, 1993; Armstrong and McIlveen, 2000). This cooking technique is reported to improve meat flavour where the use of vacuum packaging reduces the development of potential oxidative off-flavours. As the cooking temperatures are low compared with traditional cooking regimes, enhanced meat tenderness and juiciness scores have similarly been reported in final cooked products (Ghazala and Trenholm, 1998). The principal processing concerns related to sous vide cooking relate to food safety considerations and effective pasteurisation of end products due to the low temperatures employed (Sheard and Rodger, 1995; Armstrong and McIlveen, 2000). For example: • Sous vide foods usually lack added chemical preservatives which normally arrest biological activity in processed foods. • Gentle heat treatment only kills vegetative forms of pathogens where the core temperature reaches 60 °C (140 °F). It is impossible to monitor core temperature without an invasive probe. Portion control and packaging regimes must be rigorously monitored to remove leakers. • While reduced oxygen packaging extends product shelf-life by retarding aerobic microorganisms it can, however, facilitate the outgrowth of anaerobic pathogens such as Cl. botulinum, Clostridium perfringens and Bacillus cereus, and facultative anaerobes such as L. monocytogenes. • Sufficient cooling must be rigorously applied to prevent bacterial reproduction at all stages of preparation, storage and regeneration. Thus, foods must be of the highest quality and handled within strictly maintained temperature ranges according to HACCP and food safety procedures (Rasco, 1997). Frying The high heat conductivity and capacity achieved in frying applications makes oil a superior heat transfer medium for very high temperature

© Woodhead Publishing Limited, 2011

640

Processed meats

cooking to air or water. Usually frying temperatures are recorded above the boiling point of water, with foods being cooked in the temperature range of 165–185 °C while dwell times are usually quite short (i.e. from 30 s up to 5 min) and determined based on product size and type (Gunstone, 2004; Armando et al., 2009). The majority of industrial frying systems are continuous in design where food product is conveyed through a reservoir of heated oil via a twin (top and bottom) belt configuration. Oil is heated indirectly via coils or jacket systems (employing electric, gas or thermal oil as energy sources) in tandem with oil recirculation (pumping) systems to ensure optimal heat transfer. Similarly, oil filtration systems are fitted to remove food particles or soil from the heating fluid. Frying units are usually enclosed units fitted with adequate exhaust extractors to effectively handle the emissions – smoke – generated from heated oils. These units are usually fitted with fire suppression systems due to the elevated temperatures and potential conditions for auto-combustion of frying oils at elevated temperatures. During frying the surface heat migrates towards the product interior by conduction under unsteady state conditions with resulting heat transfer rates dependent upon the thermal properties of the food including: thermal diffusivity, specific heat and product density (Singh, 1995; Vijayan and Singh, 1997). The elevated frying temperatures cause a rapid food product surface dehydration leading to the development of the unique crispy texture (or crust) associate with such products (Rao and Delaney, 1995; Farkas et al., 1996). Product dehydration in tandem with oil absorption/adsorption defines the principal mass transfer mechanisms recorded during frying (Thanatuksorn et al., 2010). This rapid dehydration of the exterior surface of the food causes an outward migration of water from its interior. Evaporation and water migration from the foods surface cools the surrounding oil at the product/oil interface and prevents excessive dehydration and surface burning (Blumenthal, 1991; Sosa-Morales, et al., 2006). Textural changes (i.e. crust formation and crispiness) together with fat absorption/adsorption result in the unique ‘fried flavour’ development and surface colours identified as key organoleptic attributes desired by consumers (Saguy and Dana, 2003). Numerous starches have been assessed in batter formulation with different starch types having an effect on product quality (Altunakar et al., 2004). The use of these unique coating and breading systems have the ability to enhance product appearance and reduce the excessive dewatering and crust formation evident in uncoated, cooked meat surfaces. In RTE meats, products can be either pre-cooked (95 °C, 99% RH) prior to coating or fried after coating (180 °C, 5% RH). These cooking protocols are dependent upon the meat product type (i.e. geometry and weight), as well as processing equipment and line configurations employed. Batters are usually defined as liquid mixtures made from water, flour, starch and seasoning, and can be categorised into two types: adhesion (or interface) batters or tempura (or puff) batters (Mallikarjunan, 2004). Breading

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

641

is usually defined as anhydrous crumb derived from cereal flour or a product thereof and applied on a previously battered coated food to form a crust with a particulate texture (Maskat and Kerr; 2002; Fiszman, 2009). Coating quality and composition are critical criterion in batter formulation and the ability of the batter to adhere to the meat product must be considered carefully. Coating application is usually controlled as a function of batter temperature and viscosity in tandem with line speeds. Numerous approaches to oil reduction and absorption in fried products have been assessed, focusing upon cooking technologies (time/temperature regimes), ingredients selected (chemical compounds), as well as pre-treatment (pre-drying, osmotic pre-treatment and blanching) employed (Blumenthal, 1991; Saguy and Dana, 2003). Unfortunately the precise mechanism for oil pick-up in fried products is difficult to elucidate owing to the complexity of the process (Bouchon et al., 2003). Dana and Saguy (2006) further described oil uptake of fried products through three possible mechanisms, namely: water replacement, cooling-phase effect and surface-active agents. Thus, depending upon the particular study, product oil adsorption/absorption can occur during the cooking process (especially in the case of extended frying dwell times), or post-frying where processing oil is absorbed into the coating as the product cools (i.e. cooking phase effect). Product and processing protocols will clearly impact upon the importance of each effect and will vary from application to application (Kassama and Ngadi, 2004, Thanatuksorn et al., 2010). The elimination of the pre-frying step after batter addition is of significant commercial interest to processors due to its problematic nature (oil contamination issues, reduced oil quality etc.), as well as the desire to potentially reduce oil pick-up levels in final products (Salvador et al., 2005). Recent developments in batter formulations have focused on the use of hydrocolloids (long chain polymers), especially cellulose derivatives, as well as dairy proteins as potential lipid blockers, which can form a barrier to fat absorption during frying (Albert and Mittal, 2002). Moreover, application of modified pre-dust and/or batter/breading formulations containing cellulose-based ingredients in tandem with hot water cooking (80 °C) as a prefrying step have similarly been developed. These low fat, water-set, coated products are being ultimately cooked using conventional or microwavetype oven systems rather than traditional frying techniques (Fiszman, 2009). It is important to note that the use of starch (polysaccharide)-based batter and breading applications in combination with very high (frying) temperatures can lead to potential acrylamide formation in fried products, a known carcinogen and is an issue that has received much interest in recent years (Zyzak et al., 2003; Granda and Moreira, 2005). The quality of frying oil has an intimate contribution to the quality of fried food. Repeated use of oil at elevated temperatures in the presence of meat protein, moisture and air can lead to thermal degradation of the oil. This includes oil hydrolysis, oxidation and polymerisation (Mellema, 2003;

© Woodhead Publishing Limited, 2011

642

Processed meats

Dana and Saguy, 2006). Selection of suitable frying oil must be completed based on the process of interest, specific application, storage and shelf-life of the finished product as well as the acceptable production costs (Podmore, 2002). Nutritional considerations dictate that a good quality frying oil should possess low levels of free fatty acids (FFA), saturated and trans unsaturated acids and high levels of cis monounsaturated acids. Unsaturated fats are more likely to undergo oxidative degradation. Therefore, despite the nutritional value of essential polyunsaturated fatty acids, frying oils should be low in polyunsaturation to provide higher oxidative stability (Innawong et al., 2004). Vegetable oils of choice for frying include soybean, cottonseed, corn, peanut, palm, olive, canola, safflower and sunflower oil. Olive oil, canola oil and peanut oil are the most widely used oils with high level of unsaturation. Canola oil and sunflower oil are usually partly hydrogenated to impart a higher chemical stability during frying. Palm oil is also suitable for frying due to the high level of natural antioxidants in its composition (Moreira et al., 1999).

25.4.3 Radiation-based systems Microwaves and radio waves belong to the volumetric heating technologies. They are termed volumetric because the heat is first generated inside the meat. In radiative heating, processed meat composition (e.g. levels of water, salts, fats, proteins) will influence absorbance across the radiation spectrum and cooking characteristics (Wang et al., 2003a). Thus, radiation heat transfer/absorbance is not concerned with radiation energy levels per se, but rather the nature/composition of the meat and the nature of the radiation (wavelengths employed, etc.). Infrared cooking Infrared (IR) radiation (employing wavelengths of 0.78 to 1000 µm), similar to microwave, radio frequency (RF), and induction heating, transfers thermal energy in the form of electromagnetic (EM) waves which encompasses that portion of the EM spectrum bordering on visible light and microwaves (Fig. 25.7). Certain characteristics of IR heating such as efficiency, wavelength and reflectivity set it apart from and make it more effective for certain foods than for others. In the case of meat applications this has been realised as continuous dry heat systems for flash roasting/browning of meat surfaces. It has also been reported that the presence of fat has no effect in mid-IR radiation and, in the case of far IR radiation, a number of mechanisms reduced the cooking time more than with mid-IR radiation cooking (Dagerskog and Österstro, 1979; Sheridan and Shilton, 2002). IR heating has also recently gained in popularity because of its higher thermal efficiency and fast heating rate/response times in comparison with

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies Wavelength

1 nm 10 100 X-rays

643

1 µm 10 100 1 mm 1 cm10 1 m 10 100

UV rays Visible rays Infrared rays Microwave Radio wave Microwave Television Radio oven

UV HH FF

Wavelength

3 µm

Near infrared rays 0.78 µm

FA MM

2.5 µm

Far infrared rays

Wavelength used in industrial fields

30 µm

1 mm

Fig. 25.7 Outline of general frequency bands and wavelengths employed for infrared applications.

conventional heating techniques. IR has been applied to various thermal processing operations within the food industry including dehydration, frying and pasteurisation (Sakai and Hanzawa, 1994; Datta and Ni, 2002). In meat applications, IR heating is attractive primarily for its surface heating applications (Shilton et al., 2002; Krishnamurthy et al., 2008). Commercial IR heating units are usually designed as tunnel systems employing a continuous belt mechanism with cooking dwell times based on belt speeds. Element banks are usually fixed at a set height within the unit. However, as heating is usually top heating only due to the construction of the IR cells, uniform browning of products can only be achieved by flipping or turning products during conveyance through the IR system proper. Conveyance speed and heating levels (i.e. use of multiple independent element banks) are usually the principal modes of process control and adjustment. One minor drawback with IR-based systems relates to their effective cleaning and maintenance. Heating banks are composed of individual electrical element cells housed within a ceramic or similar insulating-type block. Heating elements may be difficult to access (depending upon oven design), as well being quite fragile and can damage easily during cleaning. Microwave and RF Microwave and RF heating encompasses all systems that employ EM waves of certain frequencies to generate heat in a food material (Fig. 25.7). Foods are non-ideal capacitors which are able to store and dissipate electrical energy from EM fields (Mudgett, 1994). Dielectric heat is generated by direct interaction between EM waves and foods as opposed to slow heat

© Woodhead Publishing Limited, 2011

644

Processed meats

conduction as in conventional heating (Ryynanen, 1995; IFT, 2000). Owing to congested bands of microwave and RF already being used for communication purposes, only a limited number of bands are allocated (e.g. in the USA by the Federal Communications Commission, FCC) for industrial, scientific and medical (ISM) applications. Typically, commercial microwave food processing within the USA employs frequencies of 2450 and 915 MHz (i.e. 2450 MHz frequency being used in domestic ovens). It is worthwhile to note that frequencies of 433.92, 896 and 2375 MHz are also available for use outside the USA. RF heating refers to heating the dielectric materials with EM energy between 1 to 300 MHz (Orfeuil, 1987; Tang et al., 2002). Other frequencies are also allocated for ISM use in various countries. For example, 42, 49, 56, 84 and 168 MHz are permitted in the UK, and 433.92 MHz is allocated in Austria, the Netherlands, Portugal, Germany and Switzerland (Metaxas and Meredith, 1993) as outlined in Table 25.3. Cooking with microwave and RF involves two main mechanisms, namely dielectric and ionic heating. Water in the food is often the primary component responsible for dielectric heating. Because of their dipolar nature, water molecules try to follow the electric field associated with EM radiation as it oscillates at the very high frequencies. Such oscillations of the water molecules produce heat (friction). The second major mechanism of heating with microwaves and RF is through the oscillatory migration of ions in the food that generates heat under the influence of the oscillating electric field (Meda et al., 2005). Inside the microwave oven, when incident and reflected microwaves interact, standing wave patterns are formed. These patterns have maximum and minimum values at certain distances from the reflecting surface. The incident and reflected waves are always in continuous motion (Lorenson, 1990). Inside a microwave oven, possibilities are high for multiple reflections and hence there are a number of standing wave patterns, leading to non-uniformity in energy distribution. Effective application of RF energy to foods is significantly influenced by applicator selection or electrode design. Traditionally, heating has been accomplished by creating a uniform electric field between two parallel

Table 25.3 Frequencies assigned by the FCC for industrial, scientific and medical use Frequency Radio Microwaves

13.56 MHz ± 6.68 kHz 27.12 MHz ± 160.00 kHz 40.68 MHz ± 20.00 kHz 915 MHz ± 13 MHz 2450 MHz ± 50 MHz 5800 MHz ± 75 MHz 24125 MHz ± 125 MHz

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

645

plates. This approach is capable of heating thicker materials uniformly because a high voltage gradient can be established within the material. However, the technique does not perform as well on thin products. To establish a high voltage gradient within a thin product the plates must be set quite close together, which can cause a potential arcing between the plates. The stray field electrode design was subsequently developed for thin materials creating an electric field between alternating parallel rods. This system provides a higher voltage gradient in the products, leading to accelerated heating. A variation on this electrode design is that of the staggered stray field design which provides more uniform heating in thicker products. As a general rule, materials less than 0.6 cm thick utilise the stray field design; with products of 0.6–1.3 cm employing the staggered stray field design. Products >1.3 cm in thickness use the parallel plate configuration. Regardless of electrode design/configuration, food products are usually transported via conveyor through the system. Bands for RF heating are limited to 13.56, 27.12 and 40.68 MHz (Table 25.3). The wavelength at these designated frequencies ranges from 22 to 360 times as long as that of the two commonly used microwave frequencies (915 and 2450 MHz). This allows RF energy to penetrate dielectric materials more deeply than microwave energy (Wang et al., 2003a,b). The deeper depths of RF energy penetration through foods and the simple uniform field patterns, as opposed to the complex non-uniform standing wave patterns observed in microwave ovens, make RF heating more suitable for processing larger product geometries (Wang et al., 2003a,b). Product composition largely determines the success of RF heating. The key measure of a material’s thermal properties is the loss factor. This property determines how well a material absorbs RF energy. Materials with a high loss factor absorb energy rapidly (and consequently heat quickly). Conversely, materials with a low loss factor absorb energy more slowly. In general, polymers tend to possess low loss factors requiring longer heating times. Water by contrast has a high loss factor and as a result RF provides many opportunities in food cooking. Dielectric properties are dependent upon food composition with moisture and salt being the two primary determinants of interest (Mudgett 1994; Datta et al., 1994). Thus, temperature rise within the food is also influenced by product dwell time within the field, homogeneity of the food, convective heat transfer at the surface, and the extent of evaporation of water inside the food and at its surface. RF is perhaps best defined as an emerging technology for thermal processing of meats as no commercial applications have been cited that employ these frequencies in pasteurisation or sterilisation operations (Laycock et al., 2003; Luechapattanaporn et al., 2004). Nevertheless, these frequencies have been utilised in baking and other novel drying processes (Kasevich, 1998; Wig et al., 1999; Datta and Davidson, 2000). Microwave heating in contrast has emerged as a novel cooking process within both domestic and industrial environments. The application of

© Woodhead Publishing Limited, 2011

646

Processed meats

microwave energy to heat foods was patented in 1945 by Percy Spencer of Raytheon Corporation as an offshoot of radar technology developed during World War II (Buffler, 1993). The first RadarangeTM became available for foodservice use in 1947 and commercially ovens were subsequently introduced in 1955. It is reported that approximately 93% of US households currently own a microwave oven, primarily for use in reheating previously cooked, chilled or frozen foods (Fusaro, 1994). The energy source in microwave systems is that of the magnetron or generator which produces microwaves through the interaction of strong electric and magnetic fields. The magnetron is a vacuum tube that uses a magnetic field to affect the flow of electrons from the cathode to the anode. When power is supplied, an electron-emitting material at the cathode becomes excited and emits electrons into the vacuum space between the cathode and anode. The anode is composed of resonant cavities that act as oscillators and generates electric fields. Microwave energy from the magnetron flows down the waveguide, a hollow metallic tube, into the oven. As the waves enter the cavity, they are dispersed by a mode stirrer, causing multiple reflections of the energy to minimise ‘hot spots’ and ‘cold spots’ in the oven cavity (Knutson et al., 1987). One of the advantages of microwave heating is that cooking dwell times are short which helps retain the organoleptic qualities and that is the basis for preferring microwave processing to conventional thermal processing systems. In calculating the process time, the dwell times in microwave heating cannot be given nearly as much importance as in conventional heating. Moreover in conventional heating, maximum temperature is limited by the heating medium temperature. Since microwave absorption continuously generates heat, product temperatures continue to rise during the microwave heating process. To maintain heating temperature profiles within reasonable limits, microwaves need to be turned on and off (cycled) once the target temperature has been achieved. Based on the method of heating the issue of localised heating and identification of the cold spot becomes a significant challenge (Goksoy et al., 1999; Vadivambal and Jayas, 2010). Use of conventional metal sheathed temperature probes is not feasible in microwave systems. However, with the advent of fluorescent fibre optic or fluoroptic thermometry, food temperatures can be successfully measured during heating and satisfactory temperature profiles can be characterised (Berek and Wickersheim, 1988). Temperature profiles of foods generated during microwave heating using such systems are dependent upon the number of probes used and their positioning within meat products. Although these probes provide detailed information only on discrete points within samples, they can provide invaluable information regarding temperature equilibration within samples as a function of time and energy application. Product composition, in particular moisture and salt levels, play a much greater role on microwave processing than in conventional cooking due to their influence on product dielectric properties. High salt and moisture

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

647

contents increase the efficiency of microwave absorption, thereby decreasing the depth of penetration. Thus, interior locations are generally heated to a lesser degree in foods with high salt or moisture contents resulting in reduced microbial destruction. Product composition can also lead to changes in the thermal properties such as specific heat, density and thermal conductivity thereby altering the magnitude and uniformity of the temperature rise. For example, the temperature of a low specific heat oil increases at a much faster rate than that of water when compared at the same level of absorbed power. The different components of mixed food products, such as multicompartment frozen dinners, will heat differently (Ryynanen and Ohlsson, 1996; Zhang and Datta, 2000). Packaging materials are also a critical process factor in such applications. In contrast to commercial canning, where metal containers offer minimal thermal resistance and are not a critical process factor, metallic components present in a package, such as aluminium foil and susceptors, can dramatically influence the heating rates of the packaged food. Many techniques have been employed to improve the uniformity of heating. These include rotating and oscillating packaged meats, as well as employing a suitable external absorbing medium (such as hot water) around meat products (Lau et al., 1998) to reduce evaporative losses and promotion of thermal equilibration following heating (Fakhouri and Ramaswamy 1993). Microwave oven chamber design can significantly affect the magnitude and/or spatial variation of the power absorption within the meat or food product (Fig. 25.8). The presence or absence of devices added to improve temperature distribution and the orientation/position of foods inside the oven similarly have a significant influence on the magnitude and uniformity of power absorption (Wig et al., 1999). Extraction fan

Magnetron Absorbing load Chokes Mode stirrers

Continuous conveyor

Product

Fig. 25.8 Outline of typical (batch) continuous microwave system.

© Woodhead Publishing Limited, 2011

648

Processed meats

Table 25.4 Food Package Process Equipment

Critical process factors in microwave heating Shape, size, composition (moisture, salt, and so on), multiple components (as in a frozen dinner), liquid against solid Presence of metallic elements such as aluminium foil, susceptor Power level, cycling, presence of hot water or air around the food, equilibration time Dimensions, shape and other electromagnetic characteristics of the oven, frequency, agitation of the food, presence of mode stirrers and turntables

Other factors related to the equipment are the temperature of the medium surrounding the product and the level of food surface evaporation (especially significant for unpackaged food), both affecting food surface temperature. Power level and cycling of the microwave input are identified as critical process factors. Power output generated by the magnetron also changes as the magnetron heats up over time. Thus, a specific ‘wait time’ may be necessary before the power output becomes stable in the microwave system. Owing to differences in penetrating ability, the frequency of the microwaves can dramatically affect the heating rates and their spatial distribution. In a simplified view, a lower frequency of 915 MHz has a higher depth of penetration than 2450 MHz (as employed in domestic microwave appliances). At this lower frequency, uniformity of heating can improve with reduced edge heating (Lau et al., 1998). Equilibration of the product following heating can help to level the temperature distribution and improve uniformity (Fakhouri and Ramaswamy, 1993). A summary of the various product, package, process and equipment factors discussed above is provided in Table 25.4. Because of the number of critical factors implicated, none of them alone can be treated as a critical process factor by itself, unless all others are held constant. Future possibilities to improve the uniformity of heating include variable frequency microwave processing and phase control microwave processing. Although these two techniques have been employed in several non-food applications, they are yet to be applied to food in any significant way. Combinations of microwave and conventional heating in many different configurations have also been used to improve heating uniformity. The critical process factor in combination heating or any other novel processes remains the temperature of the food at the cold point, primarily due to the complexity of the energy absorption and heat transfer processes. Ohmic heating Ohmic heating (also referred to as Joule heating) is defined as a process wherein (primarily alternating) electric currents are passed through foods or other materials with the primary purpose of heating them. Heating occurs in the form of internal energy generation within the material. This is distinguished from other electrical heating methods either by the

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

649

presence of electrodes contacting the food (as opposed to microwave and inductive heating, where electrodes are absent), frequency (unrestricted, except for the specially assigned RF or microwave frequency range) and waveform (also unrestricted, although typically sinusoidal). Ohmic heating may be used to heat food internally by passing an electric current through it, thereby reducing potential thermal abuse of treated product unlike conventional heating, where slow heat penetration occurs (Sastry and Li, 1996; Sarang et al., 2008). Ohmic heating is an internal energy generation process and technically there is no upper temperature limit for the process on this basis. However, where production bottlenecks occur it is also feasible for boiling to occur within the system even with a high degree of pressurisation (Fryer et al., 1993). Equipment designs that are commercially available include electrodes that are located at various positions along the length of the product flow path (in-line field), or alternatively located perpendicular to the flow (cross-field) which impacts on general operation of the system. In the in-line field design, the device generally operates at high voltage and relatively low current. Products are heated as it flows through the heating field, so its electrical conductivity changes over the length (i.e. dwell time). Since the total voltage drop in the heater must equal the applied voltage, the material at the upstream end experiences high field strengths and downstream locations experience lower field strengths. In the cross-field design, the field strength is constant throughout the system. Thus, ohmic heating has potential for continuous sterilisation of low acid food containing particulates (Palaniappan and Sastry, 2002). As the process is fundamentally thermal-based, minimal temperature at the coldest point(s) and product dwell time within the active field are the principle critical process factors in realising effective sterilisation. Successful thermal treatment of solid-liquid mixtures is based upon satisfactory location of the cold spots within the product stream (Sastry and Palaniappan, 1992; Sastry and Li, 1996). General electrical properties of meat have been investigated (Sarang et al., 2008; Saif et al., 2004). Other studies have reported conductivities of different pork cuts (at 20 °C) and observed that lean is highly conductive compared with fat. The heating rate has also been shown to be directly proportional to the electrical conductivity and the square of the electric field strength (Sastry and Palaniappan, 1992; Shirsat et al., 2004). Bozkurt and Icier (2010) in a recent study employed different voltage gradients (20, 30 and 40 V/cm) to minced beef–fat blends (e.g. added fat levels of 2%, 9% and 15%). Factors affecting electrical conductivity were reported as temperature and mince composition. Although the effect of initial fat content on electrical conductivity was statistically significant, voltage gradient did not affect the electrical conductivity changes during cooking. Electrical conductivity of the samples increased with increasing temperature up to the critical initial cooking temperature (60–70 °C) depending on the fat level, and then decreased due to structural changes and the increase in the bound water during cooking.

© Woodhead Publishing Limited, 2011

650

Processed meats

A critical factor in the development of ohmic heating systems for cooking meats is likely to be that of fat content (or the presence of similar adjuncts that negatively impact on heat transfer). If fat globules are present within a highly electrical conductive region where currents can bypass the globule, it may heat slower than its surroundings due to its lack of electrical conductivity (Bozkurt and Icier, 2010). Under such conditions, any pathogens potentially present within the fat phase may receive less treatment than the rest of the product. Heating of the fat phase may then depend upon the rate at which energy is transferred from the surrounding media. Thus, a high heat transfer coefficient may not necessarily relate to the worst case, since fluid motion tends to moderate heating in such situations. If a fat-rich (low conductivity) phase is aligned to significantly intercept the current, it is possible for such a zone to heat faster than the surrounding fluid. In any event, care must be taken in establishing the process.

25.4.4 Hybrid/novel cooking systems Traditionally, the meat processing industry has been reluctant to make expensive investments in novel technologies that have not been proven as thoroughly reliable in large-scale or long-term use and as a result it requires considerable effort and cost to deliver novel cooking systems to market. This is clearly understandable based on the capital expenditures involved in the installation of large-scale industrial cooking systems (capable of cooking up to approximately 8000 kg/h), as well as the food safety (product validation) considerations and related processing reliability issues that must be clearly reconciled in advance of any novel cooking system being deemed commercially acceptable and fit for purpose. Moreover, the importance of pasteurisation and sterilisation requirements in RTE products and the emergence of multi-drug-resistant bacterial strains have all contributed to increases in cooking (core) temperatures in tandem with effective rapid chilling techniques to optimise the process. Accurate oven processing controls (recipedriven programming, user-friendly human machine interface (HMI) systems, etc.) and validation tools (temperature data-loggers) are prerequisites for controlled consistent cooking. Novel line controls and optimal heating regimes translate into line efficiencies (increased throughputs, cooking flexibility, energy recovery as well as integrated CIP systems, etc.). Meat products are considered more difficult to heat efficiently since they usually cannot be effectively pumped or stirred. The challenge in cooking meats using traditional systems is that they either cause over-cooking of food surfaces or require long cooking times as the heating needs to extend through the entire meat mass (Wappling-Raaholt et al., 2002). The use of pre-steaming systems (i.e. spiral or serpentine-type steam cooking systems) in tandem with an impingement cooking (roasting) unit is one practical approach towards generating high throughput lines with optimal yields (>5000 kg/h) and consistent core temperatures. Cooking in saturated steam

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

651

is desirable as product yields and heat transfer rates are optimal. The key to efficient roasting of meat products is to ensure that product dwell times in a high temperature (dry) heat are minimised. Clearly the advantage of employing traditional convection-based cooking methodologies is that validation of pasteurisation effects is more straightforward. An additional consideration in the development of hybrid cooking systems is that of footprint which should be small. Alternative attempts in line optimisation and reduction of cooking dwell times have been achieved where volumetric (electromagnetic) heating (e.g. IR, RF, microwave or ohmic heating) systems are employed as either preheating or post-heating process in combination with traditional continuous convection heating systems (Krishnamurthy et al., 2008). The main advantages of continuous hybrid systems lie in the fact that they can potentially accelerate cooking processes and significantly increase line throughput efficiencies (i.e. increased productivity and reduced energy consumption). Improving heat transfer rates within meat products further impact on water migration, as well as product shrinkage and is manifest as improved organoleptic acceptability and textural scores for ultimate cooked products. One of the main challenges in continuous cooking systems is that of product temperature validation. While this has been effectively addressed in static oven systems where product is heat treated in batch format, the challenges surrounding continuous lines and potential under-cook scenarios cannot be underestimated. Based on these challenges, Echo Ovens Ltd, recently developed and launched an automated ‘smart’ temperature and colour monitoring system for use on continuous cooking lines that can autoaccept or reject meat products (based on pre-set temperature and colour specifications) after cooking. This apparatus is a significant development in continuous cooking systems introducing on-line product (pasteurisation) validation. Moreover, the real time monitoring achieved by this system (ECHO CT-100) means that it can be interfaced into the existing ECHO impingement oven automation systems in order to develop efficient feedback loop controls and effective auto-adjustment of cooking protocols. Thus parameters (plenum heights, heating temperatures, steam levels, fan and belt speeds, etc.) which can impact on product heating regimes can be independently and automatically adjusted based on programme logic and ultimate cooked meat data generated. This is an exciting development in continuous thermal processing operations and illustrates the technological advances in commercial cooking systems that are now possible due to novel automation and machine vision technologies.

25.5 Consumer preference The shift in consumer preferences for convenience has been largely driven through a change in working patterns and lifestyle choices which places a

© Woodhead Publishing Limited, 2011

652

Processed meats

significant pressure on meal planning and a significant reduction in time spent in the kitchen. In the last decade meal preparation times have been reduced from 60 min to <30 min. Despite the proliferation of cooking shows, cooking magazines, cooking classes and cookbooks, less and less actual cooking is taking place in American homes (Beck, 2007). This trend has been reported in many developed countries where there is a shift towards RTE-type meats and fast convenient food options. Moreover, a number of recent consumer studies have indicated a significant shift in consumer eating patterns and an increase in dining out and consumption of mass catering generated foods. The US beef industry launched an advertising campaign in the late 1990s with the tagline ‘Beef, it’s what’s for dinner’. This campaign aimed to inform consumers and beef industry channels about the new trend – beef dishes that are fully cooked and ready to microwave and serve in 10 min, including pot roasts, meat loaf and beef ribs (Resurreccion, 2003). Understanding the quality attributes that are important to consumers is the key to designing RTE products to meet consumers’ needs and desires. As there is no such thing as an ‘average’ consumer, with average products being usually perceived to be mediocre by all, this emphasises the importance of being able to describe the sensory characteristics of a product category. Understanding these differences and generating a suitable language and organoleptic mapping system is the first step to elucidating what drives consumer preference and response (Findlay, 2004). The end-point (core) temperatures for meats manifest as degrees of doneness are defined as 65 °C (medium rare), 70 °C (medium) and 75 °C (medium well) (AMSA, 1995). Effective cooking of bone in product requires that products are cooked to core temperatures of >85 °C (in order to effectively set the bone marrow and blood fractions). Development of surface colour and roasting requires direct exposure of meats to dry heat, this is particularly important in the case of skin on meat products (poultry and pork, etc.). Clearly the toughness of the meat cut and levels of connective tissue will further dictate the mode and degree of heating possible. For example, Neely et al. (1999) showed that customer satisfaction with top round steak was dependent upon how it is cooked, with higher ratings been given to steaks cooked to ‘medium rare’ or less, or to ‘very well’ degrees of doneness (i.e. stir-frying, braising, and simmering and stewing were preferred at lower degrees of doneness) as well as individual consumer preference. While beef chuck roasts contribute up to 26% of the carcass, which is the largest percentage of any beef primal, its palatability issues due to the number of muscles and their fibre orientation make it a challenge to cook. Adhikari et al. (2004) showed that grilling, under medium rare conditions, was most suitable for the chuck muscles because it yielded more juiciness and roasted flavour than any other cooking method/temperature combination.

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

653

Flavour development in meats, although complex, is based on the cooking techniques and temperatures employed, type of meat/meat cut, seasonings utilised and cooking dwell times. Studies on beef bouillon (beef extract) have shown that the macromolecular materials obtained from heated soluble collagen and tropomyosin fractions can enhance meaty flavour of broths, and suggested that collagen and tropomyosin were precursors of the macromolecular meaty flavour enhancer (Kuroda and Harada, 2004). Flavour development in such broths is significantly influenced by processing temperatures employed (Cambero et al., 1992) which can similarly alter other meat proteins present including myosin (Tajima et al., 2001). Interestingly, the complexity of flavour development within meat stocks (i.e. chicken bouillon versus bonito stock from Katsuwonus pelamis) is also dependent upon consumers’ perception of flavour and regional acceptability for such flavours (Kohno et al., 2005). Flavour development within cooked meats has been associated with the term umami (based on the Japanese word for ‘delicious’). Umami is the taste of meat and in particular the savoury taste of monosodium glutamate (MSG), together with its synergistic enhancer inosine monophosphate (IMP). Umami is based on binding of MSG and IMP to the Tas1R1 and Tas1R3 heterodimer, a molecule that shares the Tas1R3 subunit with the sweet taste receptor (Li et al., 2002; Nelson et al., 2002). The complexity of RTE meat-based products from formulation, preparation and thermal processing through to marketing and ultimate consumer preference-selection are influenced by a multiple of consumer quality cues including: product visual appearance and packaging, value for money, convenience (i.e. nominal preparation times), as well as wholesomeness, quality, safety and consistency. It is this latter quality cue of consistency that is most important in order for processors to achieve repeat sales over time. In terms of thermal processes, inconsistent cooking profiles will result in uneven browning, textural defects, misshapen cooked products, pasteurisation validation issues as well as possible issues with flavour profiles.

25.6 Future trends The general observation that current microbial inactivation models fail to account for all of the factors relevant to commercial thermal processes is certainly of no comfort to an industry that is increasingly being compelled to verify and prove that cooking systems are meeting lethality performance standards. Thus, there is a significant need for user-friendly, publicly available, validated models (and interactive databases for the input of raw temperature data) that would allow a processor to enter specific product conditions (geometry, weight, composition, initial temperature, etc.) and process parameters (cooking equipment specifications/type, cooking temperatures, time, air velocity, humidity, etc.), for each stage of a multi-stage

© Woodhead Publishing Limited, 2011

654

Processed meats

process and generate a prediction of product temperature profiles and rates of pathogen inactivation. Such a functional tool could ultimately be employed in the design and control of multi-stage processes (hurdle management) to ensure that the lethality performance standards are met in RTE meats while simultaneously optimising cooking yield and product quality. While predictive models are under development for certain specific processes, such as contact frying (Zorrilla et al., 2003; Erdogdu and Dejmek, 2010) and convection cooking (Murphy et al., 1999), there is significant work required for the generation of continuous-flow operations for use in typical process plants. Moreover, the ability to generate accurate profiles for individual oven systems would require the endorsement of manufacturers and suppliers. While the challenges of developing such models are great, the rewards are clearly evident especially with the advent of food globalisation, and growing awareness of food security issues (i.e. harmonisation of pasteurisation and sterilisation requirements and guidelines between importing–exporting territories). Commercial cooking systems can create complex conditions around the product, with varying profiles for temperature, humidity, airflows and wavelengths, which will all impact on ultimate models for various heating systems. Scale-up of laboratory-based inactivation data to commercial-scale processes, without evidence that the data account for all of the relevant process parameters is clearly a dangerous assumption. In the meantime, processors should be cautious in applying simple D and z-values to integrated time– temperature histories from process data. Minimally, they should be aware of the medium and heating conditions used to generate the inactivation parameters, and adequately factor for any process variations versus model data (i.e. product composition and effectiveness of individual heating and cooling steps). While under-cooking in food manufacturing facilities is not currently causing widespread food safety problems per se, continued development of processes and new products with extended shelf-life in tandem with ongoing regulatory changes and the emergence of resistant pathogenic strains of bacteria, all necessitate a proactive approach in ensuring efficient evaluation of thermal process lethality in RTE products. Systems such as the ECHO CT-100 on line temperature and colour monitoring unit, for example, illustrate how automation and microprocessor developments and capabilities can allow for the emergence of ‘smart’ automatic cooking systems (employing feedback loop controls, etc.). Similarly, advances in radiation-based thermal processing systems including improvements in frequency generators/power sources and fibre optic (temperature) detection systems will clearly allow such heating technologies to evolve and expand their current range of applications (e.g. tempering/defrosting and pre-heating operations) to encompass more complex cooking operations. Such novel systems will lead to further improvements in cooking throughputs while minimising overall line footprint requirements. The recent emergence of hybrid microwave/impingement oven

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

655

systems that can significantly reduce cooking dwell times are a further signal of how commercial RTE cooking lines will develop into the future. Naturally, the challenges in maintaining product wholesomeness (i.e. flavour, colour and texture) in such novel cooking systems compared with traditional ovens will remain a significant challenge. In summary, while the fundamentals of thermal processing and the physicochemical properties of meat products will remain constant, the ability to enhance the scientific and process engineering aspects of oven design and ultimate performance will lead to more efficient ovens and safer RTE products going forward.

25.7 Sources of further information and advice • Campden BRI. Campden BRI is the UK’s largest independent membership-based organisation carrying out research and development for the food and drinks industry worldwide. It is committed to providing industry with the research, technical and advisory services needed to ensure product safety and quality, process efficiency and product and process innovation. Address: Campden BRI, Station Rd., Chipping Campden, GL55 6LD, UK Website: http://www.campden.co.uk E-mail: [email protected] Phone: +44(0)1386 842000 Fax: +44(0)1386 842100 • Chilled Food Association (CFA). CFA was formed in 1989 to establish, continuously improve and promote best hygienic practice standards in the production of retailed chilled prepared food. CFA represents many of the leading names in UK chilled prepared food production, supplying the retail trade. Address: PO Box 6434, Kettering NN15 5XT, UK. Website: http://www.chilledfood.org E-mail: [email protected] Phone: +44 (0)1536 514365 • Directorate General for Health and Consumers (DG SANCO). Over the years the European Union has established EU laws on the safety of food and other products, on consumers’ rights and on the protection of people’s health. The Directorate General for Health and Consumers has the task of keeping these laws up to date. It is national, regional or even local governments in EU countries that actually apply the EU’s health and consumer protection laws. It is their job to make sure traders, manufacturers and food producers in their country observe the rules. Nonetheless, part of our job is to check that this is really happening and that the rules are being applied properly in all EU countries. Address: European Commission Health & Consumers DirectorateGeneral. B-1049, Brussels, Belgium Website: http://ec.europa.eu/dgs/health_consumer/index_en.htm

© Woodhead Publishing Limited, 2011

656

Processed meats

• Echo Ovens Ltd. Supplier of continuous impingement heating and cooling technologies and related ancillary equipment for the value added meat processing industry. Address: Unit 4 Limerick Food Centre, Raheen Business Park, Raheen, Limerick, Ireland Website: http://www.echovens.ie E-mail: [email protected] Phone: +353-61-302022 Fax: +353-61-307169 • European Hygienic Engineering & Design Group (EHEDG). The principal goal of EHEDG is the promotion of safe food by improving hygienic engineering and design in all aspects of food manufacture. The EHEDG is essentially a consortium of equipment manufacturers, food industries, research institutes as well as public health authorities and was founded in 1989 with the aim to promote hygiene during the processing and packing of food products. EHEDG actively supports European legislation, which requires that handling, preparation processing and packaging of food is done hygienically using hygienic machinery and in hygienic premises (EC Directive 2006/42/EC for Machinery, EN 1672-2 and EN ISO 14159 Hygiene requirement). Address: EHEDG Secretariat, c/o VDMA Food Processing and Packaging Machinery Association, Lyoner Straße 18, D-60528 Frankfurt/Main, Germany Website: http://www.ehedg.org E-mail: [email protected] Phone: +49 69 66 03-12 17 Fax: +49 69 66 03-22 17 • Food Safety Authority of Ireland (FSAI). The principal function of the Food Safety Authority of Ireland (FSAI) is to take all reasonable steps to ensure that food produced, distributed or marketed in the state meets the highest standards of food safety and hygiene reasonably available. The FSAI aims to ensure that food complies with legal requirements, or where appropriate with recognised codes of good practice. Address: Abbey Court, Lower Abbey Street, Dublin 1, Ireland. Website: http://www.fsai.ie/home.html E-mail: [email protected] Phone: +353 1 817 1300 Fax: +353 1 817 1301 • Spirax-Sarco UK Ltd. Spirax-Sarco is a commercial supplier of steam valves and related steam services/equipment. Address: Charlton House, Cheltenham, GL53 8ER, UK Website: http://www.spiraxsarco.com E-mail: [email protected] Phone: +44 (0)1242 521361 Fax: +44 (0)1242 573342 • USDA Food Safety and Inspection Service (FSIS). FSIS is the public health agency in the US Department of Agriculture responsible for ensuring that the nation’s commercial supply of meat, poultry and egg products is safe, wholesome, correctly labelled and correctly packaged. Address: Food Safety and Inspection Service US Department of Agriculture 1400 Independence Ave., S.W. Washington, DC 20250-3700, USA Website: http://www.fsis.usda.gov/

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

657

25.8 References adhikari, k., keene, m.p., heymann, h. and lorenzen, c.l. (2004). Optimizing beef chuck flavor and texture through cookery methods Journal of Food Science, 69(4): SNQ174–SNQ180. albert, s. and mittal, g.s. (2002). Comparative evaluation of edible coatings to reduce fat uptake in a deep-fried cereal product Food Research International, 35: 445–458. altunakar, b., sahin, s. and sumnu, g. (2004). Functionality of batters containing different starch types for deep-fat frying of chicken nuggets European Food Research and Technology, 218(4): 318–322. alvarado, c. and mckee, s. (2007). Marination to improve functional properties and safety of poultry meat Journal of Applied Poultry Research, 16: 113–120. amsa (1995). Research guidelines for cookery, sensory evaluation and instrumental tenderness measurements of fresh meat. Chicago, IL: American Meat Science Association National Live Stock and Meat Board, 1–47. angioletti, m., di tommaso, r.m., nino, e. and ruocco, g. (2003). Simultaneous visualization of flow field and evaluation of local heat transfer by transitional impinging jets. International Journal of Heat and Mass Transfer, 46: 1703–1713. armando, a., vélez, c. rada-mendoza, m., villamiel, m. and villada, h.s. (2009). Heat transfer coefficient during deep-fat frying Food Control, 20(4): 321–325. armstrong, g.a. and mcilveen, h. (2000). Effects of prolonged storage on the sensory quality and consumer acceptance of sous vide meat-based recipe dishes Food Quality and Preference, 11: 377–385. asghar, a., samejima, k., yasui, t. and henrickson, r.l. (1985). Functionality of muscle proteins in gelation mechanisms of structured meat products Critical Reviews in Food Science and Nutrition, 22(1): 27–106. beck, m.e. (2007). Dinner preparation in the modern United States British Food Journal, 109(7): 531–547. berek, h.e. and wickersheim, k.a. (1988). Measuring temperatures in microwavable packages Journal of Packaging Technology, 2: 164–168. betts, g.d. (1996). Code of practice for the manufacture of vacuum and modified atmosphere packaged chilled foods with particular regard to the risks of botulism. CCFRA Guideline No. 11. Campden and Chorleywood Food Research Association, Chipping Campden, UK. bissett, r.l., cheng, m.s.h. and brannan, r.g. (2010). A quantitative assessment of the Research Chefs Association core competencies for the practicing culinologist Journal of Food Science Education, 9(1): 11–18. blumenthal, m.m. (1991). A new look at the chemistry and physics of deep-fat frying Food Technology, 45(2): 68–94. bottani, e. and volpi, a. (2009). An analytical model for cooking automation in industrial steam ovens Journal of Food Engineering, 90(2): 153–160. bouchon, p., aguilera, j.m. and pyle, d.l. (2003). Structure oil–absorption relationships Journal of Food Science, 68: 2711–2716. bozkurt, h. and icier, f. (2010). Electrical conductivity changes of minced beef–fat blends during ohmic cooking Journal of Food Engineering, 96(1): 86–92. brannan, r.g. and osborne, b. (2004). Culinology and the future of the meat industry Proceedings of the 57th American Meat Science Association Reciprocal Meat Conference, Lexington, Kentucky, 91–92. brashear, g., brewer, m.s., meisinger, d. and mckeith, f.k. (2002). Raw material pH, pump level and pump composition on quality characteristics of pork Journal of Muscle Foods, 13(3): 189–204. buffler, c.r. (1993). Microwave Cooking and Processing, Van Nostrand Reinhold, New York.

© Woodhead Publishing Limited, 2011

658

Processed meats

cambero, m.i. seusst, i. and honikel, k.o. (1992). Flavor compounds of beef broth as affected by cooking temperature Journal of Food Science, 57(6): 1285–1290. chang, h.c. carpenter, j.a. and toledo, r.t. (1998). Modelling heat transfer during oven roasting of unstuffed turkeys Journal of Food Science 63(2): 257–261. cheng, q., and sun, d-w. (2008). Factors affecting the water holding capacity of red meat products: a review of recent research advances Critical Reviews in Food Science and Nutrition, 48(2): 137–159. cheng, q., sun, d.w. and scannell, a.g.m. (2005). Feasibility of water cooking for pork ham processing as compared with traditional dry and wet air cooking methods Journal of Food Engineering, 67(4): 427–433. church, i.j. and parsons, a.l. (1993). Review: sous vide cook–chill technology International Journal of Food Science and Technology, 28(6): 563–574. cornforth, d.p., rabovitser, j.k., ahuja, s., wagner, j.c., hanson, r., cummings, b. and chudnovsky, y. (1998). Carbon monoxide, nitric oxide, and nitrogen dioxide levels in gas ovens related to surface pinking of cooked beef and turkey Journal of Agriculture and Food Chemistry, 46: 255–261. cox, p.w. and fryer, p.j. (2002). Heat transfer to foods: modelling and validation Journal of Thermal Science, 11(4): 320–330. cronin, k., caro-corrales, j., tobin, j. and kerry, j.f. (2008). Impingement cooking of meat products: effect of variability on final temperature Food Science and Technology International, 14: 241–250. dagerskog, m. and österstro, m.l. (1979). Infra-red radiation for food processing I. A study of the fundamental properties of infra-red radiation. Lebensmittel-Wissenshaft und-Technologie, 12(4):237–242. dana, d. and saguy, s.i. (2006). Review: Mechanism of oil uptake during deep-fat frying and the surfactant effect-theory and myth Advances in Colloid and Interface Science, 130(2): 267–272. datta, a.k. and davidson, p.m. (2000). Microwave and radio frequency processing Journal of Food Safety 65: 32–41. datta, a.k. and ni, h. (2002). Infrared and hot-air-assisted microwave heating of foods for control of surface moisture Journal of Food Engineering, 51(4): 355–364. datta, a.k., sun, e. and solis, a. (1994). Food dielectric property data and its composition-based prediction. In: Engineering Properties of Food, Ed. Rao, M.A. and Rizvi, S.S.H., Marcel Dekker. New York, pp. 457–494. datta, a.k., geedipalli, s.s.r. and almeida, m.f. (2005). Microwave combination heating Food Technology, 59(1): 36–40. dibben, d. (2000). Electromagnetics: fundamental aspects and numerical modeling. In: Handbook of Microwave Technology for Food, Ed. Datta, A.K. and Anatheswaran, R.C., Marcel Dekker, New York. diéguez, p.m., beriain, m.j., insausti, k. and arrizubieta, m.j. (2010). Thermal analysis of meat emulsion cooking process by computer simulation and experimental measurement International Journal of Food Engineering, 6(1): Article 8. erdogdu, f. and dejmek, p. (2010). Determination of heat transfer coefficient during high pressure frying of potatoes Journal of Food Engineering, 96(4): 528–532. european union (1989). Directive 89/392/EEC of the 14-06-89 on the approximation of the laws of the Member States relating to machinery Official Journal of the European Union, L183, 29.6, 9. european union (2003). Directive 2003/89/EC Indication of the ingredients present in foodstuffs Official Journal of the European Union, L308/15–18. european union (2004). Corrigendum to Regulation (EC) No 854/2004 of the European Parliament and of the Council of 29 April 2004 laying down specific rules for the organisation of official controls on products of animal origin intended for human consumption Official Journal of the European Union, L226, 83, 25/06/2004.

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

659

european union (2006). Directive 2006/42/EC of the 17–05-06 on machinery, and amending Directive 95/16/EC (recast) Official Journal of the European Union, L157/24–L157/86. fakhouri, m.o. and ramaswamy, h.s. (1993). Temperature uniformity of microwave heated foods as influenced by product type and composition. Food Research International, 26: 89–95. farkas, b.e., singh, r.p. and rumsey, t.r. (1996). Modeling heat and mass transfer in immersion frying. II, Model solution and verification Journal of Food Engineering, 29(2): 227–248. findlay, c. (2004). Perceptual mapping and opportunity identification Proceedings of the 57th American Meat Science Association Reciprocal Meat Conference, Lexington, Kentucky, USA, pp. 109–113. fiszman, s.m. (2009). Coating ingredients In: Ingredients in Meat Products: Properties, Functionality and Applications, Ed. Tarté, R., Springer Science & Business Media LLC, New York, pp. 253–290. fleischman, g.j. (1996). Predicting temperature range in food slabs undergoing long term low power microwave heating Journal of Food Engineering, 27(4): 337– 351. fowler, a.j. and bejan, a. (1991). The effect of shrinkage on the cooking of meat International Journal of Heat and Fluid Flow, 12(4): 375–383. fryer, p.j., dealwis, a.a.p., koury, e., stapley, a.g.f. and zhang, l. (1993). Ohmic processing of solid-liquid mixtures: heat generation and convection effects Journal of Food Engineering, 18: 101–125. fsai (2006). Guidance Note Number 20: Industrial Processing of Heat-Chill Foods. Food Safety Authority of Ireland, Dublin, pp. 1–53. fusaro, d. (1994). Catching the next microwave Prepared Foods, 163: 33–35. gaze, j. (2005). Microbiological aspects of thermally processed foods Journal of Applied Microbiology, 98: 1381–1386. ghazala, s. and trenholm, r. (1998). Concepts in sous vide and cook–chill products. In: Sous vide and Cook–Chill Processing for the Food Industry, Ed. Ghazala, S., Aspen Publishers: Gaithersburg, MD, pp. 295–309. ghisalberti, l. and kondjoyan, a. (1999). Convective heat transfer coefficients between air flow and a short cylinder–Effect of air velocity and turbulence. Effect of body shape, dimensions and position in the flow Journal of Food Engineering, 42: 33–44. goksoy, e.o., james, c. and james, s.j. (1999). Non-uniformity of surface temperatures after microwave heating of poultry meat Journal of Microwave Power and Electromagnetic Energy, 34(3): 149–160. gordon, a. and barbut, s. (1990). The role of the interfacial protein film in meat batter stabilisation Food Structure, 9: 77–90. gordon, a. and barbut, s. (1992). Effect of chloride salts on protein extraction and interfacial protein film formation in meat batters Journal of the Science of Food and Agriculture, 58: 227–238. gould, g.w. (2000). Strategies for food preservation. In: The Microbiological Safety and Quality of Food, Vol. I., Ed. Lund, B.M., Baird-Parker, T.C. and Gould, G.W., Aspen Publishers Inc., Gaithersburg, MD, pp. 19–35. granda, c. and moreira, r.g. (2005). Kinetics of acrylamide formation during traditional and vacuum frying of potato chips Journal of Food Process Engineering, 28: 478–493. gunstone, f.d. (2004). The Chemistry of Oils and Fats: Sources, Composition, Properties and Uses, Blackwell Publishing Ltd, Oxford, UK, pp. 238–256. heddleson, r.a. and doores, s. (1994). Factors affecting microwave heating of foods and microwave induced destruction of foodborne pathogens – a review Journal of Food Protection, 57(11): 1025–1037.

© Woodhead Publishing Limited, 2011

660

Processed meats

heldman, d.r. and newsome, r.l. (2003). Kinetic models for microbial survival during processing Food Technology, 57(8): 40–46, 100. hendrickx, m., maesmans, g., de cordt, s., noronha, j., van loey, a. and tobback, p. (1995). Evaluation of the integrated time temperature effect in thermal processing of foods CRC Critical Reviews in Food Science and Nutrition, 35: 231–269. holownia, k., chinnan, m.s. and reynolds, a.e. (2003). Pink color defect in poultry white meat as affected by endogenous conditions Journal of Food Science, 68(3): 742–747. holtz, e. and skjöldebrand, c. (1986). Simulation of the temperature of a meat loaf during the cooking process Journal of Food Engineering, 5: 109–121. huang, e. and mittal, g.s. (1995). Meatball cooking–modeling and simulation Journal of Food Engineering, 24: 87–100. innawong, b., mallikarjunan, p. and marcy, j.e. (2004). The determination of frying oil quality using a chemosensory system Lebensm. Wiss. u. Technol. 37: 35–41. ift (2000). Kinetics of microbial inactivation for alternative food processing technologies. Report of the Institute of Food Technologists for the Food and Drug Administration of the U.S. Department of Health and Human Services Institute of Food Technologists, pp. 283–286. jolley, p.d. and purslow, p.p. (1988) Reformed meat products: fundamental concepts and new developments. In: Food Structure: Its Creation and Evaluation, Ed. Mitchell, J.R. and Blanshard, J.M.V., Butterworths, Surrey, pp. 231–264. jolley, p.d. and sheard, p. (1990). Restructured and reformed meat products: a review of the literature. Report for Meat and Livestock Commission, Milton Keynes, UK, pp. 1–89. kassama, l.s. and ngadi, m.o. (2004). Pore development in chicken meat during deep-fat frying Lebensmittel-Wissenshaft und-Technologie, 37: 841–847. kasevich, r.s. (1998). Understand the potential of radiofrequency energy Chemical Engineering Progress, 94(1): 75–81. kerry, j.f., stack, f. and buckley, d.j. (1999a). The rheological properties of exudates from cured porcine muscle: effects of added non-meat proteins Journal of Science Food and Agriculture, 79(10): 101–106. kerry, j.f., morrissey, p.a. and buckley, d.j. (1999b). The rheological properties of exudates from cured porcine muscle: effects of added polysaccharides and whey protein/polysaccharide blends Journal of the Science of Food and Agriculture, 79(10): 1260–1266. knutson, k.m., marth, e.h., wagner, m.k. (1987). Microwave heating of food Lebensmittel-Wissenshaft und-Technologie, 20: 101–110. kohno, k., hayakawa, f., xichang, w., shunsheng, c., yokoyama, m., kasai, m., takeutchi, f. and hatae, k. (2005). Comparative study on flavor preference between Japanese and Chinese for dried bonito stock and chicken bouillon Journal of Food Science, 70(3): S193–S198. krishnamurthy, k., khurana, h.k. jun, s., irudayaraj, j. and demirci, a. (2008). Infrared heating in food processing: an overview Comprehensive Reviews in Food Science and Food Safety, 7: 2–13. kuroda, m. and harada, t. (2004). Fractionation and characterization of the macromolecular meaty flavour enhancer from beef meat extract Journal of Food Science, 69(7): C542–C548. larkin, j.w. and spinak, s.h. (1996). Safety considerations of ohmically heated, aseptically processed, multiphase low-acid food products Food Technology, 50(5): 242–245. lau, m.h., tang, j., taub, i.a., yang, t.c.s., edwards, c.g. and younce, f.l. (1998). Microwave heating uniformity of food during 915 MHz microwave sterilization process. Proceedings of the 33rd Microwave Power Symposium, pp. 78–81.

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

661

laycock, l., piysana, p. and mittal, g.s., (2003). Radio-frequency cooking of ground, comminuted and muscle meat products Meat Science, 65: 959–965. ledward, d.a. (1994). Protein–polysaccharide interactions In: Protein Functionality in Food Systems, Hettierachchy, N.S. and Ziegler, G.R., Mercel Dekker Inc., New York. pp. 225–259. lee, c.m., carroll, r.j. and abdollahi, a. (1981). A microscopical study of the structure of meat emulsions and its relationship to thermal stability Journal of Food Science, 46: 1789–1804. lee, s.h., datta, a.k. and rao, m.a. (2007). How does cooking time scale with size? A numerical modeling approach Journal of Food Science, 72(1): E001–10. leedl, f. and schleichere, e. (1990). New aspects of the maillard reaction in foods and in the human body Angewandte Chemie International Edition, 29: 565–708. li, x., staszewski, l., xu, h., durick, k., zoller, m. and adler, e. (2002). Human receptors for sweet and umami taste Proceedings of the National Academy of Science USA, 99: 4692–4696. lorenson, c. (1990). The why’s and how’s of mathematical modeling for microwave heating Microwave World, 11(1): 14–23. luechapattanaporn, k., wang, y., wang, j., al-holy, m., kang, d.h., tang, j. and hallberg, l.m. (2004). Microbial safety in radio-frequency processing of packaged foods Journal of Food Science, 69(7): 201–206. macfarlane, j.j., schmidt, g.r. and turner, r.h. (1977). Binding of meat pieces: a comparison of myosin, actomyosin and sarcoplasmic proteins as binding agents Journal of Food Science, 42: 1603–1605. mallikarjunan, p. (2004). Understanding and measuring consumer perception of crispness. In: Texture in Food, Ed. Kilcast, D., Woodhead, Cambridge, UK., pp. 82–103. marcotte, m., chen, c.r., grabowski, s., ramaswamy, h.s. and piette, j.p.g. (2008). Modelling of cooking-cooling processes for meat and poultry products International Journal of Food Science and Technology, 43(4): 673–684. maskat, m.y. and kerr, w.l. (2002). Coating characteristics of fried chicken breasts prepared with different particle size of breading Journal of Food Processing and Preservation, 26: 27–38. meda, v., orsat, v. and raghavan, g.s.v. (2005). Microwave heating and the dielectric properties of foods. In: Microwave Processing of Food, Ed. Schubert, H. and Regier, M., Woodhead Publishing Ltd, Cambridge, UK, pp. 61–75. meinert, l., schäfer, a., bjergegaard, c., aaslyng, m.d. and bredie, w.l.p. (2009). Comparison of glucose, glucose 6-phosphate, ribose, and mannose as flavour precursors in pork; the effect of monosaccharide addition on flavour generation Meat Science, 81: 419–425. mellema, m. (2003). Mechanism and reduction of fat uptake in deep-fat fried foods Trends in Food Science and Technology, 14(9): 364–373. metaxas, a.c. and meredith, r.j. (1993). Industrial Microwave Heating. Peter Peregrinus Ltd, London, UK. meynier, a. and mottram, d.s. (1995). The effect of pH on the formation of volatile compounds in meat related model systems Food Chemistry, 52: 361–366. moreira, r.g., castell-perez, e. and barrufet, m.a. (1999). Deep Fat Frying: Fundamentals and Applications. Aspen Publishers, Inc., Gaithensburg, MD, pp. 179–202. morrissey, p.a., mulvihill, d.m. and o’neill, e.a. (1987). Functional properties of muscle proteins. In: Developments in Food Proteins, Ed. Hudson, B.J.F., Elsevier Applied Science London, UK, pp. 195–256. mudgett, r.e. (1994). Electrical properties of foods. In: Engineering Properties of Foods, Ed Rao, M.A. and Rizvi, S.S.H., Marcel Dekker Inc., New York, pp. 389–455.

© Woodhead Publishing Limited, 2011

662

Processed meats

murphy, r.y., marks, b.p., johnson, e.r. and johnson, m.g. (1999). Inactivation of Salmonella and Listeria in ground chicken breast meat during thermal processing Journal of Food Protection, 62: 980–985. murphy, r.y., johnson, e.r., duncan, l.k., clausen, e.c., davis, m.d. and march, j.a. (2001). Heat transfer properties, moisture loss, product yield, and soluble proteins in chicken breast patties during air convection cooking Poultry Science, 80(4): 508–514. navaneethakrishnan, p., srinivasan, p.s.s. and dhandapani, s. (2010). Numerical and experimental investigation of temperature distribution inside a heating oven Journal of Food Processing and Preservation, 34(2): 275–288. neely, t.r., lorenzen, c.l., miller, r.k., tatum, j.d., wise, j.w., taylor, j.f., buyck, m.j., reagan, j.o. and savell, j.w. (1999). Beef customer satisfaction: cooking method and degree of doneness effects on the top round steak Journal of Animal Science, 77: 653–660. nelson, g., chandrashekar, j., hoon, m.a., feng, l., zhao, g., ryba, n.j. and zuker, c.s. (2002). An amino-acid taste receptor Nature, 416: 199–202. nicolaï, b.m., verboven, p. and scheerlinck, n. (2001). Modelling and simulation of thermal processes. In: Thermal Technologies in Food Processing, Ed. Richardson, P., Woodhead Publishing Ltd, Cambridge, UK, pp. 91–112. nitin, n. and karwe, m. (2004). Numerical simulation and experimental investigation of conjugate heat transfer between a turbulent hot air jet impinging on a cookieshaped object Journal of Food Science, 69(2): E59–E65. norton, t. and sun, d-w. (2006). Computational fluid dynamics (CFD) – an effective and efficient design and analysis tool for the food industry: a review Trends in Food Science and Technology, 17(11): 600–620. obuz, e., powell, t.h. and dikeman, m.e. (2002). Simulation of cooking cylindrical beef roasts Lebensmittel-Wissenshaft und-Technologie, 35: 637– 644. offer, g. and knight, p. (1988). The structural basis of water-holding in meat. In: Developments in Meat Science, Vol. 4, Ed. Lawrie, R.A., Elsevier Applied Science, New York, pp. 89–190. orfeuil, m. (1987). Electric Process Heating. Battelle Press, Columbus, OH, pp. 539–575. orta-ramirez, a.m., bradley, p., warsow, c.r., booren, a.m. and ryser, e.t. (2005). Enhanced thermal resistance of Salmonella in whole muscle compared to ground beef Journal of Food Science, 70(7): 359–362. ovadia, d.z. and walker, c.e. (1998). Impingement in food processing Food Technology, 52(4): 46–50. palaniappan, s. and sastry, s.k. (2002). Ohmic heating. In: Control of Foodborne Microorganisms, Ed. Juneja, V.K. and Sofos, J.N., Marcel Dekker Inc., New York, pp. 451–460. pearson, a.m. and gillett, t.a. (1996). Sectioned and formed products. In Processed Meats 3rd Edition, Ed. Pearson, A.M. and Gillett, T.A., Chapman and Hall, New York, pp. 144–179. pearson, a.m. and tauber, f.w. (1984) Processed Meats, 2nd Edition, Ed. Pearson, A.M. and Tauber, F.W., AVI Publishing Co. Westport, CT. podmore, j. (2002). Culinary fats: solid and liquid frying oils and speciality oils. In: Fats in Food Technology, Ed. Rajah, K.K., Sheffield Academic Press, Sheffield, UK, pp. 332–359. polat, s. (1993). Heat and mass transfer in impingement drying Drying Technology, 11(6): 1147–1176. rasco, b.a. (1997). Product liability and HACCP Food Quality, 10: 16–18. rao, v.n.m. and delaney, a.m. (1995). An engineering perspective on deep fat frying of breaded chicken pieces Food Technology, 49(1): 138–141.

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

663

resurreccion, a.v.a. (2003). Sensory aspects of consumer choices for meat and meat products Meat Science, 66: 11–20. ryynanen, s. (1995). The electromagnetic properties of food materials: a review of the basic principle Journal of Food Engineering, 26: 409–429. ryynanen, s. and ohlsson, t. (1996). Microwave heating uniformity of ready meals as affected by placement, composition, and geometry Journal of Food Science, 61: 620–624. saguy, i.s. and dana, d. (2003). Integrated approach to deep fat frying: engineering, nutrition, health and consumer aspects Journal of Food Engineering, 56(2–3): 143–152. saif, s.m.h., lan, y., wang, s. and garcia, s. (2004). Electrical resistivity of goat meat International Journal of Food Properties, 7(3): 463–471. sakai, n. and hanzawa, t. (1994). Applications and advances in far-infrared heating in Japan Trends Food Science Technology, 5: 357–362. saltiel, c. and datta, a.k. (1998). Heat and mass transfer in microwave processing Advances in Heat Transfer, 33: 1–94. salvador, a., sanz, t. and fiszman, s.m. (2005). Effect of the addition of different ingredients on the characteristics of a batter coating for fried seafood prepared without a pre-frying step Food Hydrocolloids, 19: 703–708. sarang, s., sastry, s.k. and knipe, l. (2008). Electrical conductivity of fruits and meats during ohmic heating Journal of Food Engineering, 87(3): 351– 356. sarkar, a., nitin, n., karwe, m.v. and singh, r.p. (2004). Fluid flow and heat transfer in air jet impingement in food processing Journal of Food Science, 69(4): CRH113–CHR122. sastry, s.k. and cornelius, b.d. (2002). Aseptic Processing of Foods Containing Solid Particulates, John Wiley and Sons, Inc., New York. sastry, s.k. and li, q. (1996). Modelling the ohmic heating of foods Food Technology, 50(5): 246–248. sastry, s.k. and palaniappan, s. (1992). Mathematical modelling and experimental studies on ohmic heating of liquid–particle mixtures in a static heater Journal of Food Process Engineering, 15: 241–261. schmidt, g.r. and trout, g.r. (1984). The chemistry of meat binding In: Recent Advances in the Chemistry of Meat, Vol. 12, Ed. Bailey, A.J., The Royal Society of Chemistry, London, pp. 231–245. schnepf, m. and barbeau, w.e. (1989). Survival of Salmonella typhimurium in roasting chickens cooked in a microwave, convention microwave and conventional electric oven Journal of Food Safety, 9: 245–252. sheard, m.a. and rodger, c. (1995). Optimum heat treatments for ‘sous vide’ cook– chill products Food Control, 6: 53–56. sheridan, p.s. and shilton, n.c. (2002). Determination of the thermal diffusivity of ground beef patties under infrared radiation oven-shelf cooking Journal of Food Engineering, 52(1): 39–45. shilton, n., mallikarjunan, p. and sheridan, p. (2002). Modeling of heat transfer and evaporative losses during the cooking of beef patties using far-infrared radiation Journal of Food Engineering, 55: 217–222. shirsat, n., lyng, j.g., brunton, n.p. and mckenna, b. (2004). Ohmic processing: electrical conductivities of pork cuts Meat Science, 67: 507–514. simpson, r., teixeira, a. and almonacid, s. (2007). Advances with intelligent on-line retort control and automation in thermal processing of canned foods Food Control, 18: 821–833. singh, n., akins, r.g. and erickson, l.e. (1984). Modelling heat and mass transfer during the oven roasting of meat Journal of Food Process Engineering, 7: 205–220.

© Woodhead Publishing Limited, 2011

664

Processed meats

singh, r.p. (1995). Heat and mass transfer in foods during deep fat frying Journal of Food Technology, 49(1): 134–137. skjöldebrand, c. (1980). Convection oven frying: heat and mass transfer between air and product Journal of Food Science, 45(5): 1354–1358. skog, k. (1993). Cooking procedures and food mutagens: a literature review Food and Chemical Toxicology, 31(9): 655–675. smith, d.m. (1991). Factors influencing heat-induced gelation of muscle proteins. In: Interactions of Food Proteins, Ed. Parris, N. and Barford, R., American Chemical Society, Washington, DC, pp. 243–256. smith, d.p. and acton, j.c. (2001). Marination, cooking, and curing of poultry products. In: Poultry Meat Science, Ed. Sams, A.R., CRC Press, Boca Raton, FL, pp. 257–280. sosa-morales, m.e., orzuna-espíritu, r. and vélez-ruiz, j.f. (2006). Mass, thermal and quality aspects of deep-fat frying of pork meat Journal of Food Engineering, 77(3): 731–738. stumbo, c.r. (1973). Thermobacteriology in Food Processing, 2nd Edition, Academic Press, New York. tajima, m., ito, t., arakawa, n. and parrish jr., f.c. (2001). Heat-induced changes of myosin and sarcoplasmic proteins in beef during simmering Journal of Food Science, 66(2): 233–237. tang, j., feng, h. and lau, m. (2002). Microwave heating in food processing. In: Advances in Bioprocessing Engineering, Ed. Yang, X.H. and Tang, J., World Scientific, NJ, pp. 1–44. thanatuksorn, p., kajiwaraa, k. and suzukib, t. (2010). Characteristics and oil absorption in deep-fat fried batter prepared from ball-milled wheat flour Journal of the Science of Food and Agriculture, 90(1): 13–20. usda-fsis (1999). Performance standards for production of certain meat and poultry products. 9 CFR Parts 301, 317, 318, 320, and 381. US Dept. of Agriculture/ Food Safety Inspection Service Washington, DC. Federal Register, 64(3): 732–749. usda-fsis (2002). Microbial Sampling Of Ready-To-Eat (RTE) Products for the FSIS Verification Testing Program. Directive 10240.3 US Dept. of Agriculture/ Food Safety Inspection Service Washington, DC. usda-fsis (2006). Chapter I Title 9 Animals and Animal Products Code of Federal Regulations from the U.S. Government Printing Office via GPO Access Washington, DC, 9cfr94.4 US Dept. of Agriculture/Food Safety Inspection Service, pp. 494–498. vadivambal, r. and jayas, d.s. (2010). Non-uniform temperature distribution during microwave heating of food materials – a review Food Bioprocess Technology 3: 161–171. van loey, s., ludikhuyze, l., hendrickx, m., de cordt, s. and tobback, p. (1995). Theoretical consideration on the influence of the z-value of a single component time/temperature integrator on thermal process impact evaluation Journal of Food Protection, 58(1): 39–48. vijayan, j. and singh, r.p. (1997). Heat transfer during immersion frying of frozen foods Journal of Food Engineering, 34(3): 293–314. wang, y., wig, t.d., tang, j. and hallberg, l.m. (2003a). Dielectric properties of foods relevant to RF and microwave pasteurization and sterilization Journal of Food Engineering, 57: 257–268. wang, y., wig, t.d., tang, j. and hallberg, l.m. (2003b). Sterilization of foodstuffs using radio frequency heating Journal of Food Science, 68(2): 539–544. wang, z.j. (2006). Thermal processing of canned foods. In Thermal Food Processing: New Technologies and Quality Issues, Ed. Sun, D.W., CRC Taylor and Francis Group, Boca Raton, FL, pp. 335–362.

© Woodhead Publishing Limited, 2011

Effects of novel thermal processing technologies

665

wahlby, u., skjoldebrand, c. and junker, e. (2000). Impact of impingement on cooking time and food quality Journal of Food Engineering, 43(3) 179–187. wappling-raaholt, b., scheerlinck, n., galt, s., banga, j.r., alonso, a., balsa-canto, e., van impe, t., ohlsson, j. and nicolai, b.m. (2002). A combined electromagnetic and heat transfer model for heating of foods in microwave combination ovens Journal of Microwave Power and Electromagnetic Energy, 37(2): 97–111. wichchukit, s., zorrilla, s.e. and singh, r.p. (2001). Contact heat transfer coefficient during double-sided cooking of hamburger patties Journal of Food Processing and Preservation, 25(3): 207–221. wig, t., tang, j., younce, f., hallberg, l., dunne, c.p. and koral, t. (1999). Radio frequency sterilization of military group rations. AIChE Annual Meeting. xiong, y.l. and blanchard, s.p. (1994). Myofibrillar protein gelation: viscoelastic changes related to heating procedures Journal of Food Science, 59(4): 734–738. xiong, y.l. and brekke, p.b. (1999). Functionality of proteins in meat products. In Proceedings of the 52nd American Meat Science Association Reciprocal Meat Conference, Kansas City, MO, pp. 66–71. zeigler, g.r. and foegeding, a.e. (1990). Gelation of proteins CRC Advances in Food Nutrition and Research, 34: 204–298. zhang, h. and datta, a.k. (2000). Electromagnetics of microwave heating: magnitude and uniformity of energy absorption in an oven. In: Handbook of Microwave Technology for Food Applications, Ed. Datta, A.K. and Anatheswaran, R.C., Marcel Dekker, Inc., New York. zhang, h., datta, a.k., taub, i. and doona, c. (2001). Experimental and numerical investigation of microwave sterilization of solid foods AIChE Journal, 47(9): 1957–1968. zorrilla, s.e., banga, j.r. and singh, r.p. (2003). Dynamic optimization of doublesided cooking of meat patties Journal of Food Engineering, 58(2): 173–182. zyzak, d.v., sanders, r.a., stojanovic, m., tallmadge, d.h., eberhart, b.l., ewald, d.k., gruber, d.c., morsch, t.r., strothers, m.a., rizzi, g.p. and villagran, m.d. (2003). Acrylamide formation mechanism in heated foods Journal of Agriculture and Food Chemistry, 51(16): 4782–4787.

© Woodhead Publishing Limited, 2011

26 Packaging of cooked meats and musclebased, convenience-style processed foods M. C. Cruz-Romero and J. P. Kerry, University College Cork, Ireland

Abstract: The application of packaging systems and materials to food products is constantly evolving. Greater demands for food products, such as processed meats, possessing higher quality, greater safety and convenience continue to grow. Consequently, the packaging and processed meat industries have evolved, and continue to do so. In order to address these demands, this chapter summarises the different packaging systems and materials used to protect meat product quality and safety, while increasing the shelf-life of muscle-based cooked meats and muscle-based, convenience-style food products. Key words: cooked meat packaging, convenience-style meat products, shelf-life of cooked meats, packaging systems and materials used on cooked meat products, smart packaging.

26.1 Introduction Meat and meat products are nutritionally rich, providing a wide range of nutrients, such as proteins, fats, minerals and vitamins and constitute an important part of the European diet (Cosgrove et al., 2005). Meat has long been considered a highly desirable and nutritious food, and has become a mass consumer product throughout the world with the highest consumption rates being recorded in industrialised Western countries. Meat is a very versatile culinary product and has become a vital element of both cuisine and culture. The world production of meat in 2007 was 285.7 million tonnes (FAO, 2009) and is projected to rise by 2.1% annually to 2017 (Trostle, 2008). Total meat consumption in the EU-27 is projected to increase from 84.5 kg/head in 2006 to around 87.2 kg/head by 2014 (European Commission Directorate-General for Agriculture and Rural Development, 2009). The food and drink industry is the largest manufacturing sector in the EU. In 2008 it accounted for 12.5% of total turnover, 11% of total value-added,

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

667

and 13.5% of total employment in manufacturing. Four manufacturing industries dominate the sector: meat products accounts for 21%, dairy products for 14%, beverages for 15%, and ‘various food products’ including bakery, chocolate, confectionery products, pasta, and baby food for 26% of total turnover (CIAA, 2010). The total Western European fresh and processed meat market was worth €265.0 billion in 2008, of which the processed meat market was worth €117.3 billion or 10.6% of the overall food and drink market of €1111 billion. This market is projected to grow at an average annual rate of 0.90% during the period 2008–2011, compared with only 0.51% for the total food and drink market (FFT, 2009). Consumer preferences with respect to food are constantly changing. The most obvious trend in recent years has been the increasing demand for high quality food; with a higher degree of convenience being associated with it. Natural taste and freshness are highly appreciated, especially in cooked meat products, to increase their readiness for consumption (Rombouts et al., 2003). In certain markets, such as the UK (the largest processed food market in Europe), convenience foods such as cooked or ready-to-cook products are increasingly common. With an increase in snacking behaviour, products that are ready-to-eat are becoming ever more popular (Magdelaine et al., 2008). In the opinion of most consumers, the cooking of meat produces a product with favourable texture and taste. From a food safety perspective, the cooking of meat is necessary to eliminate any associated foodborne pathogens (King and White, 2006). Although spoilage of cooked meat products is usually microbial in origin, chemical factors may also be important. Rancidity (oxidation of fat) will develop in cooked meat products stored for prolonged periods in the presence of oxygen. One of the main priorities in any meat processing plant is to obtain the longest shelf-life for all manufactured products. The longer the shelf-life, the more time the manufacturer has to distribute, the retailer to display and the customer to store prior to consuming the products (Belcher, 2006). Consequently, good processing and packaging procedures are essential to achieving longer shelf-life. However, correct storage conditions are also essential if the potential benefits of proper processing and packaging are to be obtained. Appropriate packaging can confer a number of benefits to cooked meat products, among others; shelf-life extension, delay of microbial spoilage, maintenance of desirable colour and minimisation of water loss. The shelf-life extension of cooked meat products through packaging makes it possible for a broader geographical distribution of the packaged product. Other benefits include; greater convenience of handling, improved presentation for retailers, and the provision of a surface on which attractive and informative graphics can be printed. Realisation of these benefits is dependent on the appropriate selection of packaging materials and systems (Belcher, 2006).

© Woodhead Publishing Limited, 2011

668

Processed meats

Effective packaging of cooked food products can be seen to be just one factor, however important, out of several which, when combined, will determine the quality, safety and reliability of the cooked meat products. Packaging must protect the product physically, and it must present both the product and any information which the manufacturer wishes to, or must, convey to the purchaser and in a pleasing manner. Additionally, it should achieve these objectives with maximum reliability and minimum cost. Selection of the correct packaging material requires detailed technical knowledge. Some of the important aspects include: compatibility with existing packaging equipment, flexibility, strength, permeability of the packaging material to water vapour, oxygen and carbon dioxide, resistance to UV light, barrier properties against water, grease, oil and solvents, sealing strength, resistance to puncturing, printing characteristics, clarity and cost. In addition, any changes in the packaging material induced by processing and storage procedures, for example cooking followed by freezing, must be considered. A potential consumer decision to buy cooked meat products is influenced mainly by the appearance of the product and for meat, whether fresh or processed, this means colour (Troy and Kerry, 2010). In many ways the colour of cooked meat products is just as delicate and as sensitive to detrimental changes as that of fresh meat. Effective packaging has a substantial role to play in preserving meat colour in packaged cook meat products. Maintaining good colour in cured meat products is a very different problem from that of fresh meats (Mullan and McDowell, 2003). Good fresh meat colour requires an adequate supplementation of oxygen, while maintenance of a good cured meat colour requires the critical absence of oxygen. Packaging technologies have adapted over the years to address people’s changing lifestyles. Demands on the type of packaging (material, style, etc.) will vary according to the characteristics of the cooked meat product being packaged within it; how it is produced and distributed; where, how and to whom it is sold; how it is used, etc. Food products generally require a standard of packaging which is superior to that of most other products in order to support and comply with their main requirements, i.e. proven efficacy, safety, uniformity, reproducibility, integrity, purity with limited impurities and a good shelf-life stability profile. Time-pressed consumers, smaller households, consumer obsession with health and wellness and food safety concerns are encouraging new product formats and packaging styles for cooked meat products. It has been reported that the US demand for meat, poultry and seafood packaging is projected to exceed $9.2 billion in 2013 (Freedonia, 2009). Gains will, in part, be attributable to increased meat, poultry and seafood production, with changes in packaging practices also driving packaging opportunities. For example, processors are expanding their offerings of meat and poultry items in smaller, more convenient sizes as well as increasing the variety of items that are further processed. Such goods, which tend to use more packaging relative to their volume when compared with larger

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

669

unprocessed cuts, will continue to experience strong demand, resulting from growth in the number of smaller households and consumer demand for more convenient foods designed to simplify food preparation (Freedonia, 2009). This chapter will summarise the different packaging systems used to protect meat product quality and safety, while increasing the shelf-life of muscle-based cooked meats and muscle-based, convenience-style food products.

26.2 Cooked meat products Cooked meat products are seasoned, fully cooked and often in convenience-style and ready-to-eat formats and include sauce or gravy, so that they can be identified as a dinner entrée. The cooking procedure used is important, not just because of food safety, but also because the process chosen results in the removal of a large amount of water from the meat following protein aggregation, thereby affecting yield as well as numerous sensory and quality attributes. Even though these products are ready-to-eat, consumers prefer to eat them hot. Therefore, they are intended to be heated before consumption, but do not require another full cooking step. This saves the consumer time on preparing and cooking such a product from scratch, thereby offering great, on-the-go and proportioned value to the consumer with a quality and consistency to equal expectation. For example, a pot roast would have to be seasoned and cooked for several hours, whereas a precooked pot roast is already prepared and requires rapid but gentle heating. The packaging used for such a product must preserve the quality of the cooked meat product and must function to facilitate fast and uniform heating of the meat product. Adequate cooking of meat is necessary to inactivate microbial pathogens. This is particularly important for ground meat products and some meat product varieties where pathogens can be present internally (King and White, 2006). Today meat and meat products available in the marketplace are no longer limited to traditional product forms and numerous and novel forms of processed meats are widely available, particularly those in the form of muscle-based, convenience-style food products. Many of these products are cooked and ready to consume, or heated if required. Despite the great variety of cooked meat products, such products can be divided into seven basic groups which separate along the lines of individual product characteristics and by general processing procedures required to produce them (Table 26.1; Xiong and Mikel, 2001).

26.2.1 Effects of cooking meat and meat products Pearson and Gillett (1996) outlined the effects that cooking produces in meat and meat products, as follows:

© Woodhead Publishing Limited, 2011

670

Processed meats

Table 26.1 Cooked meat products by variety (adapted from Xiong and Mikel, 2001) Cooked meats

Processing/characteristic

Canned meats

Retort to sterilise; fully cooked; cured or non-cured Cooked, dual cooking: microwaveable or oven Low water activity, cured; refrigeration not required Cured with nitrite/nitrate, salt and adjuncts by injection or dry rub Prepared meals, breaded products, marinated products, precooked, frozen or refrigerated

Frozen meats Dry-preserved meats Cured meats Dinner meats

Sausages Luncheon meats

Non-cured, cured or fermented Deli meats; lunchables, fully cooked and ready to consume; restructured meats

Examples of cooked meat products Ham, pork luncheon meat, corned beef, beef stew Breaded boneless pork cutlet, meat loaf, steaks, deli pouch Beef jerky Hams, bacon; most deli meats Steak with vegetables, battered and/or breaded chicken, barbecue smoked pork; seasoned pork roast, beef pot roasts Breakfast sausage, frankfurters, salami, pepperoni, sliced ham, bologna and salami

• denaturation and coagulation of meat proteins, thereby altering their solubility and affecting changes in colour; • improvement in meat palatability by intensifying flavour and altering texture; • destruction of considerable numbers of microorganisms, consequently improving the shelf-life stability of meat products; • inactivation of indigenous proteolytic enzymes, thereby preventing offflavour development; • decreasing the water content of the previously raw meat, especially on the surface, thereby lowering water activity, improving peelability (for example, in frankfurters) and extending shelf-life; and • stabilisation of cured meat colour. The appearance of cooked meat can be influenced by pH, meat source, packaging condition, freezing history, fat content, added ingredients, and applied preservation treatments such as irradiation or high pressure. These factors change the ratio of different forms of myoglobin; the main pigments responsible for the ultimate colour of meat (King and White, 2006). 26.2.2 Types of deterioration on cooked meat products There are two modes of food deterioration; packaging-dependent deterioration and product-dependent deterioration (Lee et al., 2008).

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

671

Packaging-dependent deterioration refers to food deterioration that is driven by environmental factors that can be controlled through the correct choice and application of packaging materials and packaging systems. Such environmental factors consist of oxygen, moisture, microbes and UV light, from which the food may be protected by using packaging as a barrier to separate the product from these external environmental factors. The use of packaging technologies such as modified atmosphere packaging (MAP) and active packaging, may also improve the internal environment of the packaged, cooked, muscle-based food product as a means of providing greater shelf-life extension. Product-dependent deterioration is that driven by the intrinsic stability of the cooked food product itself and which has no dependency upon environmental factors or packaging application. Intrinsic stability of the cooked food product is dictated by the formulation used in the preparation of the cooked muscle-based food products and the processing conditions employed in their manufacture (Lee et al., 2008). During storage, the main factors of deterioration leading to unacceptable food quality or safety issues of cooked, muscle-based food products are physical, chemical and microbiological, such as discoloration, oxidative rancidity, increase in the numbers of spoilage microorganisms or the presence of food pathogens (Robertson, 2009; Lee et al., 2008). The processing and handling treatments received by the cooked meat product before, during and after packaging, will ultimately determine the shelf-life of the cooked food product. The most important processing aspects, in terms of later applying effective packaging materials and technologies, are as follows: • Heat processing: The main objectives of heat processing are to cook the product and to render it safe for human consumption by eliminating pathogenic organisms likely to be present in the uncooked meat product. Cooked products should be heated, at least sufficiently to achieve pasteurisation conditions, to an internal temperature (72 °C for 15 s or 63 °C for 30 min) (Shapton and Shapton, 1993). If the cooking process is adequate, the viable numbers of bacteria present at the end of the cooking process will be very low. This is a major step towards effective packaging because no amount of subsequent care in the selection and use of packaging materials or in chilled storage will eliminate the risk of food poisoning or poor shelf-life performance introduced by inadequate thermal processing. • Cooling: After thoroughly cooking the food product it is important to cool the cooked product as quickly as possible, especially in the temperature range of 54 to 4.4 °C in order to prevent spore germination. It is also important to ensure that no risk of cross-contamination exists for the cooked product during the cooling process. For example, contamination of certain cooked meat products during the cooling process could be prevented by ensuring that the membrane or casings used around the

© Woodhead Publishing Limited, 2011

672

Processed meats

products during the cooking process remained intact until the cooling process was completed. Another example is to avoid moving retorted meat products from the retort, particularly those in rigid metal cans, until they have been cooled in situ. Traditionally, cans at the end of a retorting process would have to be cooled by removing them from the retort and dropping them into a water cooling tank. This process caused dents and distortions in cans which could signal loss of containment. In modern retorts, this has been overcome by fitting water cooling systems internally within the retorts. • Handling: Products which are to be repacked after cooling will be subjected to manual handling at that stage. All equipment must be thoroughly cleaned and sanitised before use. At this stage it is very important that contamination of any kind should be minimised and this can be achieved for example by using peeling machines, collecting tubes and ensuring that work tables and personnel equipment exists and is maintained under thoroughly hygienic conditions. • Packaging: As previously described the important aspects to be considered for the selection of the appropriate packaging materials include barrier and mechanical properties, clarity of the packaging, printing characteristics and cost.

26.3 Definition of packaging and its functions The fundamental aspects of all packaging materials is that in an economical manner, they must contain, protect, preserve, inform (throughout the entire distribution process from point of manufacture to points of consumer usage) and provide convenience (at many different levels) while acknowledging the constraints placed upon their usage from both legal and environmental perspectives. As these fundamental principles apply to all forms of packaging materials and systems, it follows that irrespective of the specific level at which the packaging is industrially applied (primary – sales packaging; secondary – collation and handling packaging; or tertiary – transport packaging), all must conform to these same principles (CruzRomero and Kerry, 2008). Packaging materials used for packaging cooked food products must conform to the fundamental principles outlined above and satisfy all that is required of the product from both technical (containment, protection and preservation (Fig. 26.1)) and sales (cost, convenience, sales information, labelling information, legal requirements, environmental requirements) perspectives. 26.3.1 Driving forces for packaging consumption There are powerful trends and drivers in the packaging sector leading to an increase in packaging consumption and equally powerful forces

© Woodhead Publishing Limited, 2011

Packaging of cooked meats Environment

Packaging system

673

Cooked muscle-based food product

Oxygen

O2 permeation

Oxidation, colour changes,

Carbon dioxide

CO2 permeation

Carbon dioxide loss, microbial growth

Nitrogen

N2 permeation

Nitrogen loss, packaging collapse

Water vapour

Water vapour permeation

Dehydration, texture changes

Water vapour

Water vapour permeation

Texture change, water activity change, microbial growth

Aroma permeation

Aroma and/or flavour change

Aroma Light

Light transmission Migration of packaging constituents

Colour, flavour, nutrient degradation Changes in the organoleptic quality of the product, toxicity

Fig. 26.1 Interactions of packaging with the cooked food products and the environment (adapted from Linssen and Roozen, 1994).

demanding a reduction in packaging use (Miller, 2005). The tension created between these opposing forces is driving the manufacturing industries down new and uncharted routes of development. Miller (2005) has outlined the driving forces for greater and lesser packaging consumption and these have been updated here. Driving forces for greater packaging consumption • Ageing population and smaller households. • Greater wealth, more impulse consumption and an increasing demand for convenience among consumers. • Growing requirements for brand enhancement/differentiation in an increasingly competitive market. • The trend towards ‘on-the-go’ lifestyles among increasingly time-poor consumers. • The move towards smaller pack sizes as the incidence of families eating together at the dinner table become less common. • Longer and more complex supply chains. • Rising health awareness among consumers.

© Woodhead Publishing Limited, 2011

674 • • • •

Processed meats

Desire for fewer preservatives and more ‘natural’ food. Increasing consumer demands for greater food safety. Improvements in packaging functionality. E-commerce.

Driving forces for less packaging consumption • Packaging material and distribution costs. • Increasing awareness of environmental issues, and the adoption of new regulatory requirements on packaging recycling. • Public pressure to reduce packaging volumes. • Climate change combat and carbon footprint. • Push towards ‘sustainable’ packaging. • Technical developments that reduce packaging volume for fitness for use. 26.3.2 Packaging requirements for muscle-based cooked food products The packaging requirements for muscle-based cooked food products are complex. Unlike inert packaged commodities, muscle-based cooked food products often constitute dynamic systems with limited shelf-life and specific packaging requirements. Packaging systems should not only ensure that the cooked product is microbiologically safe, make it easy to handle and convey pack information to the consumer, but also retain the desired sensory characteristics of the food. Such retention of sensory characteristics requires the package to act as a barrier to moisture, aroma or light, depending on the sensitivity of the particular cooked food product and the prevailing environment (Stöllman et al., 2000). Application of materials for packaging of cooked food products is challenging, since the demands made upon the packaging materials by the cooked food are often complex owing to specific requirements in terms of oxygen and water vapour permeability, mechanical properties, and safety issues. Packaging materials for cooked meat products must meet the food packaging requirements applied to conventional packaging materials. Therefore, packaging material used to pack cooked meat products must remain unchanged and function safely and effectively until meeting their ultimate disposal (Haugaard and Mortensen, 2003). The requirements for packaging materials used for cooked food products relate to mechanical and barrier properties (oxygen, carbon dioxide, water, light, aroma), safety aspects (migration), resistance properties (temperature and chemical resistance), production and forming requirements (welding, moulding, etc.), convenience, optical properties (transparency and opacity) and marketing requirements (communication, marking and printing properties). Therefore, the packaging technologies used by the cooked meat industry fundamentally provide product protection, convenience and safety, while

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

675

also addressing consumer expectation for quality and product freshness through the delivery of cooked meat product quality, colour, flavour and texture. Packaging is also a critical component of value-added cooked meat products offered for export and domestic markets. Identifying the unique requirements for packaging systems in different countries can increase export market opportunities for value-added cooked meat products.

26.4 Influence of key trends on consumer behaviour As previously highlighted, consumers demand high quality, natural, nutritious, visually acceptable and convenient cooked meat products, possessing all of the expected natural flavours and sensory attributes, while possessing an appropriate shelf-life (Aymerich et al., 2008). As consumers increasingly demand food that is healthy, convenient and preparation-friendly, the selection of appropriate packaging materials to ensure that the food’s nutritional value and shelf-life are maintained will become more complex (Verghese, 2008). Key trends are exerting powerful influences on consumer behaviour across the food industry, social classes and age groups. These trend cycles are emerging more rapidly as a result of economic volatility, technological progress in the food industry and a growing willingness to accept new product ideas (Rexam, 2009). Changing consumer lifestyles are driving the market for ready-meals in Europe and the USA. Changes in demographics and public health concerns make consumers focus on health and wellness. Rising health concerns mean that consumers are more aware of the influence of their diet on their health and consequently, changes in eating habits are altering accordingly. The need for convenience also continues to pervade all aspects of people’s lives. In a world where consumers are working longer hours, spending more time commuting; time is becoming an increasingly precious commodity. Consequently, consumers are in search of more efficient and effective products that help to free up and maximise their increasingly limited leisure time (Rexam, 2009). Consumers are highly influenced by the convenience attributes of cooked food products, whether it is simplicity or multiplicity of use, ease of storage, portability or even features that help to save time when making purchasing decisions, such as colour coding which can range from helping to segregate products based on identity through to being used to aid in the reading and interpretation of product information (such as, for example, the traffic light system used for product labelling). Another trend, especially noticeable in Western Europe and the USA, is in the reduction in sales of food and beverages in restaurants and bars. People spend more time at home with friends and family and less time socialising outside the home. Attempting to take advantage of this trend, meat processing companies are manufacturing cooked food products that replicate the restaurant experience at home, thereby, creating opportunities

© Woodhead Publishing Limited, 2011

676

Processed meats

for innovative packaging solutions to be employed in such kinds of cooked meat products. For example, in response to demand and growth of the ‘Heat n’ Serve’ convenience food category, the Kepak group (Ireland), in conjunction with UCC, developed the ‘global cuisine range’ (Fig. 26.2) consisting of precooked meat joints (beef, pork, chicken and turkey) combined with natural gravy and vacuum skin packaged in pre-formed trays. Cryovac Darfresh® vacuum skin packaging technology enables products to be cooked, shipped, stored, displayed, sold, re-heated by the consumer in the microwave in approximately 7 minutes and served all in the same package. These products have a shelf-life of up to 21 days when stored at refrigeration temperature (<4 °C) From a manufacturing perspective, vacuum skin packaging results in fewer processing steps and eliminates secondary product handling. Products can be re-heated by the consumer in a microwave without the requirement of punctured ventilation holes in the package before microwave heating. During product heating, the vacuum skin film forms a bubble,

Fig. 26.2

Global cuisine ‘Heat n’ Serve’ range (Kepak group, Ireland).

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

677

trapping moisture and flavour, subsequently self-vents and relaxes over the product. The ‘stay cool’ side handles reduce the risk of burns as the tray is removed from the microwave and eliminates handling messy hot pouches associated with current ‘Heat n’ Serve’ microwaveable meals. The package contains an easy-open feature which enables consumers to peel away the cover film and serve the heated meal (O’Grady and Kerry, 2008). With less time to prepare meals, eating on the go, the number of persons per household declining and an ageing population, our modern Western lifestyle is becoming more hectic and is placing new and challenging demands upon the food which is packaged and purchased (Verghese, 2008).

26.5 Consumer trends in food packaging Changing demographics and lifestyles impact on the type of cooked meat products demanded by consumers. While it is agreed that there is a growing older consumer market, it needs to be acknowledged that this consumer population is more technically aware and is more willing to pay for lifestyle and convenience factors, particularly those associated with the consumption of packaged cooked meat products (Butler, 2004). Therefore, the meat industry needs to respond to these changes and opportunities. Social trends also influence the choice of packaging materials used for cooked meat products. The average size of households is reducing, and daily routines have changed. Families tend to eat together less often, and with increasingly complex lifestyles, people are often obliged to eat at times convenient only to themselves. Parents who work full time cannot easily prepare a traditional family dinner and therefore, these developments have increased the demand for ‘convenience foods’, often pre-cooked and in single-portion or two-person servings. The provision of consumer convenience through packaging is an everincreasing trend, particularly for convenience-style, muscle-based, readymeals. Cooked meat producers are using packaging to respond to consumer demands for packages that are portable, resealable, ovenable, microwaveable, easy to open, self-venting, easy to grip, provide performance signals, provide contact points which prevent users getting burned following heating, etc. A market research has shown that consumers will pay more for packaging that provides desired convenience attributes (Doyle, 2008). For example, the introduction of zippered closures on flexible packages over the past 20 years has created an obvious convenience with respect to opening and resealing products so that now it is almost impossible to find consumerfriendly packages without this feature. Another example of packaging providing convenience is where it is used to portion control food products. Increasing concerns about obesity across Western Europe and the USA means that smaller sizes or portions of cooked meat food products are being viewed as correctly sized.

© Woodhead Publishing Limited, 2011

678

Processed meats

26.5.1 Product convenience A variety of designs have been incorporated into food packages in an effort to increase convenience. These designs include innovation in opening the packages, dispensing the product, resealing the package and the ultimate preparation of the product before consumption (Butler, 2008; Yam, 2009). Winder (2006) reported that the use of packaging by the consumer goes through seven stages; initial opening, use, closure, re-opening, re-use, reclosure and disposal. While one might accept all of these stages as given and perfectly straightforward, one could be forgiven for failing to see the hazards associated with a number of these stage actions. Initial opening of food products accounts for 28% of the reported accidents involving food and drink packaging. It has been reported that an estimated 67,000 people in the UK alone visit hospital casuality departments every year due to an accident involving food and drink packaging (DTI, 1997). However, it is thought that only 35% of such accidents are reported to hospitals, thereby suggesting that the real figure is more likely to be around 200,000 cases per year. At particular risk are the elderly and people suffering from visual impairment or arthritis (Winder, 2006). A survey conducted by Yours magazine of 2000 people over the age of 50 found that 91% of respondents had to ask for help in opening a package while 71% of respondents had injured themselves trying to open packaging (McConnell, 2004). Therefore, the ‘openability’ of packaging is a huge problem for older people and those with disabilities. Consequently, there is a requirement for the meat industry to address such issues and provide ‘elderly or infirm convenience’ when developing convenience-style, muscle-based, ready-meal products, not just from a public good perspective, but also from demographic and marketing perspectives. Going forward, the focus for packaging will need to be on better design (size, shape, design, etc.) and the optimum use of materials to produce easy to open packages which are consistent with the opening strength capabilities of an ageing population (Butler, 2004, 2009). Convenience in cooked meat products is one of the major benefits provided by packaging, and innovative solutions can provide major points of difference from one product to another (Emblem, 2000). Convenience features abound in modern food packaging. Social, economic and demographic influences on consumption patterns, new products to match changing lifestyles and new material technologies continuously affect the type and the amount of packaging needed (EUROPEN, 2009). Most importantly for today’s busy consumers, ease of opening and, if relevant and safe, reclosing are essential considerations (Butler, 2009). If the contents of the pack cannot be accessed and removed by the consumer without causing frustration, then the likely outcome will be that at the next time of purchase, a silent protest will register with the purchase of a competitor’s product. However, if attempts to open the pack result in damage or harm to the consumer, then the protest may not be so silent and may result in a very costly and image-damaging lawsuit against the brand owner.

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

679

The challenges of packaging for the cooked meat industry are to provide a meat product in a wide range of sizes and portions to suit the needs of different lifestyles and preferences and to provide clear, reliable information to consumers and other stakeholders who will encounter this product.

26.6 Choosing packaging materials for cooked meat products Food packaging is an integral part of food processing and a vital link between the processor and the eventual consumer for the safe delivery of the product through the various stages of processing, storage, transport, distribution and marketing. Packaging is the means by which manufacturers tell their customers about the product. Even if supplementary information is available at the point of sale, once the product is purchased, packaging is usually the only way the customer becomes informed of important product information, such as ingredient and compositional details, nutritional details, storage and usage instructions. Additionally, in the competitive market of food retailing, the product that fails to draw the shopper’s attention will remain on the shelf. Successful companies recognise the importance of using packaging to sell their products by means of distinctive features such as colour, shape, size and graphics in order to attract the purchaser. The choice of packaging materials and a system used for a specific product depends on a variety of factors, such as the nature of the food material and associated preservation requirements and on understanding how the package and the food behave, both during and following the manufacturing process (Tung et al., 2001). Ideally, a food package would consist of materials that are inexpensive, maintain the quality and safety of the food over time, are attractive, convenient and easy to use, while conveying all of the desired information required and being derived from renewable resources, thereby reducing the carbon footprint of such materials. Today’s food packages rarely, if ever, meet all of these ideal requirements. Creating a food package is as much art as science, trying to achieve the best overall result without falling below acceptable standards in any single category. Ultimately, the consumer plays a significant role in package design. Consumer desires drive product sales, and the package is a significant sales tool. The primary objective of packaging any food product is to contain and preserve that product from biotic (biological) or abiotic (non-biological) factors (Robertson, 2009). The selection of the packaging material for usage must be considered carefully so as control different physicochemical attributes, such as nature of pigments, sensory attributes and safety attributes, such as the presence and type of microorganisms present. The purpose is to delay or prevent the main deteriorative changes from occurring in products and consequently, present the products to the consumers in the most attractive form possible. However, in order that this be done, it is essential

© Woodhead Publishing Limited, 2011

680

Processed meats

that the initial quality of the meat is extremely high, because packaging can only maintain the existing quality of the cooked meat product or delay the onset of spoilage by controlling the factors that contribute to the spoilage. The product, therefore, is only protected for a limited period and as determined by the packaging system used. Thus, meat and meat products need a specialised package profile that is dependent upon the type of processing procedures used and the conditions that these products will encounter during storage and distribution. The key to successful packaging of cooked meat products is to select the package material and design that best satisfy competing needs with regard to product characteristics, marketing considerations (including distribution needs and consumer needs), environmental and waste management issues, and cost (Kirwan and Strawbridge, 2003). Balancing so many factors is difficult and also requires product-specific analysis. Factors to be considered when choosing a packaging system for cooked meat products include the properties of the packaging material, physical form and physicochemical characteristics of the cooked food products intended for packaging, possible cooked meat product/package interactions, the intended market for the product, and the desired product shelf-life. Other factors to take into consideration include: environmental conditions during storage and distribution, product end use, eventual package disposal, and costs related to the package throughout the production and distribution process (Marsh and Bugusu, 2007). Packaging for cooked meat products must perform well in all three dimensions of sustainability, i.e. people (social), profit (economy) and planet (environment). A good package should be cost-efficient and provide value to generate revenue, it should have a good user interface (handleability, information, etc.) and should use fewer resources, both raw materials and energy, should be recoverable and prevent its contents from becoming spoiled (WPO, 2008). The shelf-life of a cooked meat product is defined as the length of time that a cooked product in a container will remain in an acceptable condition for its use or application, under specific conditions of storage (Marsh, 2009). Product quality and shelf-life of cooked meat products are influenced by the product’s physical, chemical and biological characteristics, the processing conditions used, packaging characteristics chosen and their effectiveness on application; and the environment to which the cooked product is exposed to during distribution and storage (Brown and Williams, 2003). Since there are a number of variables that can affect the overall quality of a cooked product over time, the product/package/environment should be viewed as a dynamic system that is continually changing, from the time the product is packaged until the time the product is consumed. Packaged products are subjected to a number of environmental influences, including: moisture, oxygen, UV light, dust, and temperature. Biological elements include microorganisms, rodents and insects (Yam, 2009). In

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

681

addition, dropping products, incorrect storage and mishandling during distribution, as well as human tampering and other misuse, result in the physical damage to products (Robertson, 2009) amounting to many billions of dollars annually. While the package serves as a barrier between the product and the environment to which the product/package system is exposed, the degree of protection varies. This variation is particularly important in connection with the transport of gases, vapours, water vapour or other low molecular weight compounds between the external environment and the internal package environment, which is controlled by the packaging material.

26.7 Packaging materials and forms used on cooked meats and muscle-based, convenience-style food products Packaging formats for cooked meat food products vary significantly and are linked with the method of production, storage and consumer preference (Tucker, 2006). The types and forms of materials that have been traditionally used for packaging cooked meat products, include fibre-based materials (paper, paperboard), glass, metals and plastics.

26.7.1 Fibre-based materials The use of fibre-based packaging materials such as paper and paperboard is widespread throughout the food industry and the application of such materials to processed meat products and muscle-based, convenience-style ready-meals is no exception. While fibre-based packaging materials are rarely used for such products on technical grounds (poor containment properties based on strength limitations and permeability to gases and water vapour), they are, however, utilised for their sales functions (excellent printing capabilities to supply all forms of information required on commercial packs). Therefore, the use of such materials for processed meat products and muscle-based, convenience-style ready meals is as a component in laminate constructions for retorting, as cartons for sauces, stews or soups or as paperboard boxes or bag-in-box formats for use in freezers with breaded/battered products, burgers, patties or as labels or sleeves used for application with metal- or plastic-tray products such as ready-meals. While paper and paperboard are not noted for their technical strengths, they can be improved in this regard through the application of coatings, varnishes, lacquers and so on, or through the use of calendaring processes (using rollers to apply pressures and/or heat to mechanically improve the technical functions of the paper products in question). Consequently, fibrebased packaging materials such as parchment paper, waxed-paper, greaseproof paper and glassine paper. can be used because of their enhanced gas barrier properties, and are found today in retail outlets for holding

© Woodhead Publishing Limited, 2011

682

Processed meats

processed meat products, like sliced ham, salami, pastrami, corned-beef, chorizo and sausages, and also as meat product separators to prevent products like patties or burgers from sticking together when held or stored in stack formation. However, it must be stated that while such packaging materials are more functional than standard paper and paperboard forms and utilised commercially, they compare poorly in comparison to plasticbased packaging in terms of product preservation and shelf-life. 26.7.2 Glass Glass has several advantages for food-packaging applications: it is impermeable to gases and vapours, so it maintains product freshness for a long period of time without impairing taste or flavour (Marsh & Bugusu, 2007). The ability of glass to withstand high processing temperatures makes glass useful for hot-filling applications and for use with heat sterilized food products. The transparency of glass allows consumers to see the product and the overall appearance of products contained in glass (usually jars) is superior to that contained in almost all other packaging forms, thereby adding value and quality to products. Glass containers, used for the limited range of cooked meat products available in supermarkets today (usually meat pieces in various sauce compositions), are typically manufactured from clear or flint glass that provides an absolute barrier to gases, water vapour and aromas, but does not protect products which have sensitivities to UV light. The major disadvantages of glass are its weight, fragility and noise levels (especially when empty and moving on conveyor lines prior to filling) compared with other packaging materials. 26.7.3 Plastics Of all of the materials used for the packaging of processed meats or musclebased, convenience-style, ready-meals, plastic-based formats are the most popular. In general terms, the world’s annual consumption of plastic materials has increased from around 1.5 million tonnes to a near current level of 245 million tonnes in approximately 50 years. The total production of plastics in Europe was about 60 million tonnes in 2008, representing 25% of the total worldwide production of 245 million tonnes and at similar levels to that of North America, at 23%. Of the 60 million tonnes produced in Europe, 22.8 million tonnes (38%) were used for manufacturing packaging materials (APME, 2009). An analysis of plastic consumption on a per capita basis (1980–2010) showed that this has now grown from about 40 kg in 1980 to approximately 100 kg per year in North America and Western Europe, with the potential to further increase to 145 kg per capita by 2015 (APME, 2009). Unlike glass, metals and ceramics, plastics packaging materials are relatively permeable to small molecules such as gases (i.e., carbon dioxide, oxygen, nitrogen or other gases), water vapour, organic vapours and liquids.

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

683

In terms of their barrier properties, plastics packaging materials provide a broad range of mass transfer characteristics, ranging from excellent to low barrier values. The specific barrier requirements of the package system will be dependent upon the product’s characteristics and the intended end-use application. Multiple types of plastics are being used as materials in the packaging of processed meats or muscle-based, convenience-style, ready-meals, including the polyolefins (polyethylene (PE) and polypropylene (PP)), polyester (PE), polyvinyl chloride (PVC), polyvinylidene chloride (PVdC), polystyrene (PS), polyamide (PA) and ethylene vinyl alcohol (EVOH). A brief description of the positive attributes of each of these plastic materials is provided below. PE PE is a long chain, partially crystallisable polymer produced by polymerisation of ethylene gas monomers. It is tasteless, non-toxic, lighter than water, and somewhat whitish in appearance. The film obtained is translucent, impermeable to water and water vapour, chemically resistant and possesses a low temperature durability. Depending on density, PE is classified as low, medium and high density polyethylene (LDPE, MDPE and HDPE, respectively) with the lower density forms possessing the important characteristic of providing heat seals at relatively low heating temperatures for a host of packaging materials. PP PP is a very versatile plastic. The high melting point of PP makes it suitable for applications where thermal resistance is required. PP is chemically inert and resistant to most commonly found organic and inorganic chemicals. It has good water, oil and fat resistance properties. It can produce an effective heat seal within a narrow temperature range and is an excellent medium on which to print. It is a difficult material to tear initially, but once torn, can propagate the tear easily. PP films can be metallised and then heat-seal coated to produce a film with a high barrier to gas and water vapour. PP films coextruded with PS, EVOH and PE are used to form retortable pouches. Ionomers Ionomers are used as the food contact and heat-sealing layer in laminated packaging materials. Ionomers have a wide heating-sealing range and possess the unique ability to heat seal effectively over grease, water or particulate matter, possesses good grease-resistance and adheres well to most other packaging materials, including aluminium foil. PVC PVC is difficult to process by heat, since it begins to break down at about 80 °C; however, it is ideal for stretch-and-shrink retail packages. It also has

© Woodhead Publishing Limited, 2011

684

Processed meats

tremendous clinging potential and is used, but more often in the past, as in-store packaging for stretch-wrapped beef steaks, deli-style meats and sliced cured meat products. PVdC PVdC is used as one of the layers in multilayer-pouches, bags and thermoformed packages and it acts as a barrier to oxygen and water vapour. PVdC can be heat-sealed; can be printed upon and has a high temperature resistance, thereby making it a suitable plastic for use in cooking or retorting. It is used to package processed meat products, such as frankfurters, luncheon meats, hams and for a host of modified atmosphere packaging (MAP) applications. EVOH EVOH is an excellent barrier to oil, grease, organic solvents and oxygen. It is moisture-sensitive, therefore its oxygen permeability will fluctuate with humidity if not properly protected within the packaging material structure. EVOH is often placed (laminated) between layers of PP, PE and/or polyethylene terephthalate (PET) to avoid contact with liquid or moisture, thereby improving moisture-resistance. PS PS is a clear (high transparency usually), hard, brittle and low strength material used for the manufacture of disposable containers and for some packaging films. PS is easily processed via foaming to produce a rigid lightweight material (expanded polystyrene (EPS)) to form trays which have good impact protection and thermal insulation properties. Both the clear and the foamed thermoformed trays used for both fresh and processed meat applications have high oxygen permeabilities and low water and water vapour permeabilities. The brittleness of PS can be overcome by blending with styrene butadiene copolymer (SBC) and elastomeric polymer. The blend known as high-impact polystyrene (HIPS) has good tensile strength and stiffness. Styrene is one of the few materials with the thermal meltstrength that is necessary to form trays. Pas or nylons The different types of PA plastics are characterised by a number which correlates to the number of carbon atoms in the originating monomer. Nylon 6 and related polymer nylon 6.6 have meat packaging applications. They have mechanical and thermal properties similar to that of PET and therefore, are used in similar applications. Biaxially oriented PA (BOPA) film possesses a high heat resistance and has excellent resistance to stresscracking and puncture. It has good clarity, provides a good flavour and odour barrier, is resistant to oil and fat and has good printing properties. PA is frequently found coated with either PVdC or coated, laminated or

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

685

co-extruded with PE to improve heat sealing capability and moisture impermeability. Because of its strength, toughness and durability under conditions of high heat and physical pressure, PA film is often used as the external layer in retortable packaging, e.g. PA/aluminium foil/PP. PA is also used in cook-in-the-pack applications, sometimes in combination with PP or an ionomer. Polyesters The most common polyester used in packaged cooked meat products is PET. PET has excellent strength, clarity and printing properties, and also possesses a very low permeability to oxygen and a fair to low permeability to moisture. Therefore, it is ideal for use in vacuum packs, thermal pouches and cook-in-container applications for meat and muscle-based products. Polyesters have much higher heat resistances than many other plastics and, when oriented, have very high mechanical strengths. PET typically melts at 260 °C; and is ideal for high-temperature applications, such as retorting, boil-in-the-bag and for cooking or reheating in microwave or conventional radiant heat ovens, thereby inheriting the term ‘dual-ovenable’ plastic. PET can be laminated to PE or PVdC to provide good sealing properties. Polycarbonates (PC) PC are stiff, transparent, heat-resistant, very tough, hard and durable plastics. Despite their relatively high cost, they have been used for ovenable trays for frozen foods and in plates for oven-heated dinners.

26.7.4 Metal Metal containers offer an excellent alternative to glass containers based on their ability to deliver similar hermetic qualities and are used for packaging a significant number of shelf-stable cooked food products. Because of their structural integrity, metal containers have been used for quite a long time by the food industry for retorted food products which are typically processed using high temperatures and pressures; the processing regime being chosen on the basis of the time required to sterilise the most remote food component present in the packaging container using temperature and pressure in order to render the product free from the viable presence of Clostridium botulinum. Once the retorting process is completed and all cans are cooled, the meat products held within the packaging must still be contained and therefore, must still possess a hermetic seal, thereby preventing oxygen from entering the pack. This containment must remain in place, from the time that the product leaves the cannery, right up to the time before the consumer opens the pack. Metals cans moving along the distribution line must be economically designed to lower their negative carbon footprint and consequently, should be as light weight as possible, yet strong enough to resist impact, shock and vibrational stresses, be inert (non-reactive with

© Woodhead Publishing Limited, 2011

686

Processed meats

food components over a long period of time, from months to years) and designed to address issues such as consumer convenience (easy-open ring pulls, facilitating easier recycling, etc.). Metal containers used in retorting are generally three-piece and twopiece cans which are relatively heavy and bulky and container manufacture is complex (welding and double seaming, punching and drawing processes, etc.). Most cans used for packaging cooked meat products are made of thin sheets of low-carbon, tin-plated steel in order to prevent rusting. As retorted meat products contained within metal cans can be chemically aggressive, contact between the food product and the inner surface of the can could potentially cause product deterioration, package deterioration or the deterioration of both components. Consequently, high temperature resistant, inert, organic coatings can be applied to the inner surface of the cans to prevent these forms of chemical deterioration from occurring. For example, enamel, consisting of sulphur-resistant resins, is applied to the inner tin surface of steel cans to prevent corrosion of the metal through interaction with sulphur compounds produced by meat during processing. While steel cans have served as the traditional packaging backbone for commercial retorting for more than one hundred years, in the numerous forms that the sanitary can has taken, newer retorting applications have investigated the use of rigid aluminium cans (through the use of lower retorting temperatures and pressures upon chemically modifying the muscle-based product in question) or through the use of retortable laminated pouches (with one laminating layer consisting of aluminium sheeting). The lighter weights associated with these packaging materials and the increased processing times and reduced energy costs associated with their usage make these packaging materials true competitors to the traditional steel metal can. Further detail will be provided on retortable pouches later in this chapter. Additionally, aluminium, used in the form of shallow-drawn crinklewalled trays, or deep-drawn straight or rigid-edged trays, are commonly used today for muscle-based food dishes ranging from TV dinners, convenience-foods and ready-meals to oven roasts (meat portions with sauces and gravies added along with applied condiments). The trays will be found lidded with anything from waxed or laminated paperboard (mechanically held in place by the aluminium container) to plastic-based or plastic and foil-based laminates.

26.8 Developments and recent advances in the use of packaging materials for cooked meats and musclebased, convenience-style food products 26.8.1 Over-wrapping or stretch-wrapping Short-term storage of cooked meat products can be achieved by overwrapping the product with polyethylene. Some other films such as PVC or

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

687

PVdC provide tight-fitting over-wraps due to the clinging properties associated with these materials. Aluminium foil/paper laminates can protect cured meats against UV light. Another type of package called the chub pack is used for some ground processed meat-styled products. Chub packs are tubes stuffed with soft products which are twist tied or clipped at each end using metal fasteners or clips. The packaging film used for chub packs is generally polyethylene or polypropylene. 26.8.2 Vacuum packaging Vacuum packaging is the simplest means of modifying the internal gaseous atmosphere in the pack. Vacuum packaging involves manually or automatically placing a cooked meat or a convenience-style ready meal product inside a plastic film package, from which air is evacuated completely before sealing, either by physical or mechanical means. Since the internal pressure of the pack is close to 0 mbar, the packaging film collapses around the product. Food products with a delicate structure or texture are not suitable for vacuum-packaging applications. The packaging material used for vacuum packaging must possess high gas and moisture barrier properties and must be capable of heat sealing perfectly to deliver adequate containment (Robertson, 2006). The packaging material should also have good mechanical strength. Cooked meat products such as ham (Fig. 26.3) and other large irregular cuts of cooked meats are typically vacuum packaged in heat-shrinkable films such as ethyl vinyl acetate (EVA)/PVdC/EVA or nylon/EVOH/ ionomer coextruded materials or nylon-or-PET based film with a heatsealable layer (ionomer or EVA) (Dawson, 2001). Frankfurters are

Fig. 26.3 Baked Irish ham (Brady family Ltd, Ireland) vacuum packed in heatshrinkable film.

© Woodhead Publishing Limited, 2011

688

Processed meats

generally sold in twin web vacuum packages in which the base tray is an in-line thermoformed nylon/PVdC web and the closure is heat-sealed polyester (PET)/PVdC flexible material. Sliced luncheon meats and similar products are packed in thermoformed unplasticised PVC or polyacrylonitrile trays, heat seal closed with PET/PVdC (Brody, 2000). For long-term storage (shelf-life of approximately 5 months at 4 °C) of packaged cooked meat and muscle-based, convenience-style food products, the following laminates are used in conjunction with vacuum packaging: cellophane/PVdC/LDPE, polyester/PVdC/LDPE, PA/PVdC/LDPE, metallised PA/EVA, EVA/PVdC/EVA, PA/LDPE/ionomer, PVC/PVdC/LDPE (ICPE, 2005). Sous vide processing consists of the preparation of top-quality raw ingredients, precooking (if necessary), vacuum-packaging in heat-stable gas impermeable pouches or trays, sealing and cooking (pasteurisation) at a particular temperature for a certain period of time (by hot air, steam or water at 70–100 °C). After heating, the meat product is cooled to 4 °C within two to three hours of pasteurisation and stored, distributed and retailed under chill conditions (i.e. at >0 °C) and reheated before consumption (Carlin, 2000; Peck and Stringer, 2005; Cobos and Diaz, 2007). Sous-vide processing produces a food product with enhanced flavour, colour, texture and nutrient retention than conventionally cooked foods (Greed, 1998). Shelf-lives are very variable and range from 1 week to 3 months, depending on the food being processed, the particular process adopted and regulations governing product manufacture (Carlin, 2000). The application of sous-vide technology to muscle foods have some advantages, including cooking of foods in their own juices, sealing in volatile food flavours and aroma compounds in the package, minimal losses of moisture and nutrients, extended shelf-life, reduction and or prevention of off-flavors from oxidation through removal of O2 and this effect is reinforced by the use of high gas barrier packaging materials which act as a barrier to O2, no contamination of food after packaging and inhibition of the growth of spoilage aerobic microorganisms (Dawson, 2001). The optimal taste and/or texture of cooked red meat, poultry and fish are obtained when heated at relatively low temperatures (50–75 °C) for as long as several hours (Carlin, 2000). Concerns associated with sous vide processing involve the microbiological safety of muscle-based food products (Rodgers, 2004; Peck and Stringer, 2005). The relatively mild heat treatment associated with sous vide processing might permit the survival of heat-resistant and psychrotolerant, obligate and facultative anaerobes due to the low oxygen tension produced in these foods (Cobos and Diaz, 2007). Because spores may survive these low heat processes, storage at low temperature (below 4 °C) or for a restricted time at a higher temperature (e.g. up to two weeks at 10 °C) is essential to prevent the growth of psychrotrophic bacteria, especially Clostridium botulinum (Brown, 2000).

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

689

Sous vide products are formulated with few or no preservatives, are minimally heat processed and thus are not shelf-stable: the vacuum packaging inhibits the aerobic spoilage microorganisms; thus it reduces the population of microbial competitors but it is an ideal environment for the growth of some pathogens such as psychrotrophic and spore-forming organisms, including C. botulinum, that may have survived the mild heat treatment and may exhibit health risk to the consumer when improper storage or heating methods are applied (Hyytia-Trees et al., 2000). In low acid muscle-based food products, spores of C. botulinum can germinate, grow and produce toxin (Jay, 2000; Thippareddi and Sanchez, 2006). Consequently, the manipulation of pH in muscle-based ready-meals, often facilitated by the presence of sauces, can exert more safety control around such products. However, a survey of commercially available sous vide ready-meal food products concluded that the health risk associated with these products is quite low as long as very low storage temperatures are maintained (Nissen et al., 2002).

26.8.3 MAP Consumers are constantly looking for more convenience, additive-free foods, higher quality, innovative packaging concepts, more choice and better value. This consumer demand has led to the growth of MAP as a technology to improve product image, reduce wastage and extend the shelf-life quality of a wide range of processed products containing meat (Hanby and Potter, 2009). Pre-packed products offer today’s busy consumers a considerable saving in terms of time and money (Sivertsvik et al., 2002). Among the modern methods in food preservation, MAP is a consumer- and producerfriendly application. The advantages of MAP technology for both consumer and processor have facilitated its development and application. What makes MAP important is the potential to meet the consumer demands for safety, flavour, quality and convenience. Maintaining the appearance of the cooked meat that is acceptable to the consumer is critical. Current packaging systems such as MAP aim to prolong the shelf-life of the processed meat product, both by enhancing product colour and/or appearance and reducing microbial spoilage during storage (Spencer, 2005). The presence of oxygen in cooked food products is considered undesirable since it is involved in deteriorative biochemical reactions and the growth of aerobic microorganisms (Spencer, 2005). Most chilled pre-cooked food products are packaged in combinations of N2 and CO2 with little or no O2 in the package. Such atmospheres confer several benefits, including reduction of oxidative rancidity, inhibition of growth of aerobic spoilage microorganisms, suppression of mould growth by CO2, reduction in moisture loss through the packaging film, and reduced oxidative breakdown of flavour and aroma volatiles (Zagory, 1997). The synergetic effect of the appropriate gas mixture and refrigeration can double or triple the shelf-life

© Woodhead Publishing Limited, 2011

690

Processed meats

of cooked food products without compromising their organoleptic quality (Catalá and Gavara, 2000). The combination of gases used for application depends on many factors, such as the type of product being packed, packaging materials used, storage temperature, fat and moisture content, bacterial population, colour requirements (red meat), etc. The packaging system selected must have sufficient headspace to provide enough gas to interact with the entire product. The headspace must contain a reservoir of CO2 to compensate for the gas absorbed by the product and for that lost across the packaging material (Parry, 1993). The longer the required shelf-life, the larger the headspace should be. The gas mixtures recommended for typical cooked meat products are listed in Table 26.2. CO2 is highly soluble in water and fat, and the solubility increases greatly with decreasing temperature (Sivertsvik et al., 2002). The effectiveness of the gas is always conditioned by the storage temperature, resulting in increased inhibition of bacterial growth, as the temperature is decreased (Gill and Tan, 1980; Molin, 2000). The absorption of CO2 is highly dependent on the moisture and fat content of the product. The effect of CO2 on bacterial growth is complex and four antimicrobial mechanisms associated with CO2 have been identified (Parking and Brown, 1982; Daniels et al., 1985; Dixon and Kell, 1989; Farber, 1991): • alteration of cell membrane function, including effects on nutrient uptake and absorption; • direct inhibition of enzymes or decreases in the rate of enzyme reactions; • penetration of bacterial membranes, leading to intracellular pH changes; • direct changes in the physico-chemical properties of proteins. Obviously, a combination of all of these activities accounts for the overall bacteriostatic and fungistatic effects observed. In short, a certain amount of CO2 must dissolve into the product to inhibit bacterial growth (Gill and Penney, 1988). MAP requires an appropriate container designed or selected to compliment the characteristics of the food or operate effectively with the distribution and storage conditions applied to the product in question. Depending on the container manufacturer and the automatic dispensing equipment used for the product these can be classified as (Catalá and Gavara, 2000): • vertical packaging machinery for three- or four-seal pouches; • horizontal packaging machinery for wrapping or preformed trays in pouches (flow-pack); • horizontal tray thermoforming machinery with thermoformed rigid lids or flexible film seals. The packages for these products are generally high-barrier plastic laminations, either bags or lidding material sealed onto rigid trays. Most packaging

© Woodhead Publishing Limited, 2011

© Woodhead Publishing Limited, 2011

N2 (%)

70

70

70

70

30

30

30

30

Cooked, cured and processed meat products

Cooked, cured and processed fish and seafood products

Cooked, cured and processed poultry and game bird products Convenience food products

Retail

CO2 (%)

Product category

50

70

70

50

CO2 (%)

50

30

30

50

N2 (%)

Bulk

Recommended gas mix

Bacons, beef burgers, black pudding, charcuterie, chopped pork and ham, cooked sausages, corned beef, frankfurters, luncheon meats, meat jerky, meat slices, ox tongue, pastrami, pâtés, pepperoni, potted meats, rillettes, roast meats, salami, smoked reindeer, smoked venison, terines, wurst sausages Bloaters, Bombay duck, buckling, cod’s roe, cold smoked fish, fish galantine, fish rilletes, fish terrines, hot somoked fish, kippers, potted fish and shellfish, salted cod, salted anchovies, salted caviar, salted fish roes, salted jellyfish, seafood pâtés, smoked haddock, smoked halibut, smoked mackerel, smoked salmon, smoked trout, taramasalata Capon galantine, chicken ballotine, chicken roll, cured game birds, cured poultry, duck ballotine, duck pâté, duck galantine, smoked chicken, smoked duck, smoked poussin, smoked turkey, turkey bacon, turkey ballotine, turkey galantine, turkey roll Battered: fish, seafood, meats and poultry Bouchée/breaded: fish, seafood, meats and poultry Burritos, enchiladas, falafels, filled crêpes, pancakes and rolls, kebabs, omelettes, pasties, pizzas, pasta and pies containing meat, poultry, fish and seafood, quiche, roule au fromage, sandwiches, satays, sausage rolls, soufflés, spring rolls, stuffed pita bread, tacos, tostadas, vol-au-vents.

Cooked, cured and processed food items Bulk

Bag-in-box, master pack

Bag-in-box, master pack

Bag-in-box, master pack Bag-in-box, master pack

Retail

Tray sealed and thermoformed packages, flow packages Tray sealed and thermoformed packages, flow packages

Tray sealed and thermoformed packages, flow packages Tray sealed and thermoformed packages, flow packages

Typical types of packaging

Table 26.2 Typical gas mixtures used in MAP of some cooked, cured and processed meat products (adapted from Pbi-Dansensor, 2010)

692

Processed meats

is performed on thermoform/fill/seal machines using PVC/PVdC/LPDE or PET/PVdC/LPDE for the lidding material (Zagory, 1997). Two common tray packages used for cooked meat products are (Dawson and Stephens, 2004): (1) a non-barrier expanded polystyrene (EPS) tray, overwrapped with a barrier film and (2) an expanded polystyrene tray with a built-in barrier and barrier lidding seal to the tray. The package layer structure is: • Tray: HIPS (PS)/PS foam/HIPS/adhesive/barrier film/sealer. • Barrier film: 50.8–76.2 μm thick LLDPE/adhesive/PVdC coated nylon/ heat-seal coating. • Lidding: PVdC coated PET/LLDPE/63.5 μm thick EVA. The barrier materials used are either PVdC or EVOH. Nylon is used in packages of hot wings and roasted chicken lines because of its gas barrier properties, toughness, heat-resistance and forming properties. PET is used for printability, clarity and relatively low cost compared with nylon. LLDPE adds bulk, toughness and is low in cost, while EVA provides a heat sealing layer and seal strength on cooling (Dawson and Stephens, 2004). The use of MAP with cooked meat products has grown considerably in the last decade (Hanby and Potter, 2009). New developments include the use of argon instead of nitrogen for some applications, as it is suspected of having beneficial effects in reducing the spoilage of cooked meat products. Other changes have included the use of MAP in new applications, or expansion into new products in existing areas; for example ready-meals and a wide range of cooked meat products. MAP offers a wide range of new possibilities for producers, distributors and consumers of sliced cooked meat products. The beneficial effects that MAP has over vacuum packaging are in terms of extended shelf-life, improved colour stability, improved product appearance and easy separation of slices (Fig. 26.4) (Mullan and McDowell, 2003).

26.8.4 Boil and steam cooking packaging Many food products are cooked in the casings in which they are to be sold. Some of these casings are impermeable to water vapour, e.g. chubs and luncheon loaves. Others, such as cellulose casings and some laminated casings and bags, are discarded after cooking and cooling processes are completed, and the product is repacked in the material in which it will be sold. Plastic can-like containers (e.g. D-shaped containers) made of nylon, surlyn and other ethylene vinyl acetate copolymers are used for producing ‘cook-in’ hams that receive pasteurisation treatments. These products must be labelled ‘Perishable – keep under refrigeration’ (Xiong and Mikel, 2001). CFS ‘Cook-in ham’ 3-DEX® bags with meat adhesion offers a new packaging solution for the production of cooked ham where strong meat adhesion is required. The 3-DEX® was developed for a cooking temperature up

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

693

Fig. 26.4 Examples of processed meat products packaged under modified atmosphere packaging (protective atmosphere) (Denny, Kerry Foods; SuperValu, Musgrave Group, Ireland and Marks & Spencer plc, UK).

to 75 °C and five to eight hours cooking time in a mould or without a mould, closeable with clipping or sealing and perfect uniform shrink. The CFS 3-DEX is a multilayer, coextruded high performance 59 μm thickness bag, with optimised resistance against thermal stress during ‘cook-in’ applications. The barrier used is EVOH and typical applications are for pizza ham

© Woodhead Publishing Limited, 2011

694

Processed meats

and processed ham. These bags enable products to be cooked, stored, transported and sold ‘all-in-one’ package. 26.8.5 Retort sterilised packaging One of the major advantages of retorting ready-meal packages is that both food and package are thermally processed together, which allows the filled packages to be commercially sterile. As reported previously, the traditional retorted package is the metal can processed in a steam atmosphere, although glass jars, pouches and flexible plastic or aluminium trays can now be thermally treated in steam or hot water (Tucker, 2006). These containers require an air overpressure to counteract the natural expansion of the gases present in the headspace and those released from the food as it rises in temperature. However, there are even packaging exceptions to this. The use of plasticbased or laminated packaging materials can be modified to include a pressure-sensitive valve system. Typically, once food products are thermally processed or retorted, internal pack pressure builds and to avoid packs bursting, air overpressure is applied within the retort. However, in food packs containing pressure-sensitive valves, once internal pack pressure mounts to unacceptable levels, the one way valve system open to allow the release of gases or steam until the pressure is relieved, upon which the valve closes again. Innovation in the canning industry has been shaped by the changing demands of consumers for products that they consume regularly. Increasingly convenient packaging methods and rising recycling rates have created new challenges for the canning industry. The ever-growing presence of retort pouches on supermarket shelves indicates the growing popularity of this packaging format with consumers. A retort pouch is a special package in which the perishable food items are preserved by physical and/or chemical means. It is a flexible laminate, which can withstand thermal processing (Potter, 2008), and combines the advantages of packaging formats such as the metal can and boil-in-bag. Ready-to-use retort pouches are flexible packages made from multilayer plastic films, both with or without aluminium foil as one of the layers. Unlike the more typical flexible packages commonly encountered, they are made of heat-resistant plastics, thus making them suitable for processing in the retort at a temperature of around 121 °C. These retort pouches possess toughness and puncture resistance not normally required by other flexible packaging. Such materials can also withstand the rigours of handling and distribution. The material is heat-sealable and must possess excellent gas barrier properties. Retortable pouches have many advantages over canned or frozen packed food products for the food processor, distributor, retailer and consumer alike and these advantages are outlined in Table 26.3. The retort pouch is a plastic-based laminate structure that can be thermally processed like a metal can or glass, making it a shelf-stable food

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

695

Table 26.3 Advantages of retort pouches over cans or jars (adapted from Al-Baali and Farid, 2006) Advantages

Benefits

Reduced cooking times or reduced sterilisation times which is due to the material gauges used in pouches and its larger surface area per unit volume No sharp edges and lack of fragility

Improved sensory properties, improved nutrition, faster processing times, reduced energy costs

Pouches, empty and full, are lighter and take up less storage space than cans or jars Environmentally friendly

A pouched product is commercially sterile, can be eaten directly from a pouch or served on dishes Capability of serving single portions, easy preparation and opening Larger packaging facing printing area, rotogravure printing Complete product evacuation Conforms to all Food and Drug Administration (FDA) guidelines

Eliminate injuries (eliminates danger from can lid or broken glass) Reduction on the distribution costs, increased utilisation of storage space. Empty pouches occupy 85% less storage space than cans. Pouches require less energy to manufacture, process, transport and store than cans or jars, thereby minimising carbon footprint Shelf-stable at room temperature. Pouched food can be eaten cold or if heated it can be heated quickly Added convenience for single households, less food waste, elderly- and infirm-friendly, easy opening with reclosability Improved shelf and consumer appeal and better graphic capabilities Improved yields, products require less brine Readiness for market development

product. The materials employed in the manufacture of retort pouches used for muscle-based cooked food products must possess or provide the following essential attributes economically (Potter, 2008): • superior barrier quality to gas, water and light (for long-term storage of muscle food products); • ability to form and hold an adequate pack seal (to deliver containment); • toughness and puncture resistance (for physical protection during processing and distribution); • flexibility and capability of being processed (to withstand thermal processing (usually 115–121 °C), chilling, handling, retail demands, consumer demands); • inertness, so as not to impart any taint or odour to the contents;

© Woodhead Publishing Limited, 2011

696

Processed meats

• ability to meet the requirements of local and international food contact and other regulatory standards. The typical retort pouch consists of a 12 μm PET film laminated to 9 or 18 μm in-gauge aluminium foil, which is in turn laminated to a 76 μm PP film (Downing, 1996). Each of these components plays an important role in the finished flexible pouch. Externally, PET provides high temperature resistance, toughness, strength and printability. The aluminium layer provides barrier properties to light and gas required and acts to conduct and distribute heat quickly throughout the pack and to all of its components. On the inside of the pack, PP film is in direct contact with the food product and provides an exceptionally strong heat seal that can withstand all of the pressure and temperature demands of retorting, flexibility, strength and inertness on the packaged cooked meat product in contact (Downing, 1996), contributing to a product shelf-life at least equal to that of retorted cans. Filling pouches is a critical stage in the pouch processing operation. As for cans, overfilling pouches should be avoided because it not only increases the potential for contamination of the sealing area, thereby causing seal failure, but could also lead to the under-processing of the cooked food product because of the greater product volume which would cause an increase in the overall thickness of the pouch. A three-ply laminate consisting of PET/Al foil/PP (as described above) is commonly used for the packaging of ready-to-eat retort packaged food. Meat or muscle-based products packed in such laminates would be expected to possess a shelf-life of greater than one year. The other packaging materials generally used in retort pouch manufacture, includes nylon, silica-coated nylon, EVOH and PVdC (Kirwan and Strawbridge, 2003). These materials have high moisture barrier properties and are used successfully for packaging of ready-to-eat high moisture meat-based food products. The use of both preformed pouches and pouches formed on-line using form–fill–seal machines are employed (Downing, 1996; Kirwan and Strawbridge, 2003). Preformed pouches are flat or gusseted stand-up design. The typical construction of these pouches are: • flat configuration: 12 μm PET/12 μm Al foil/75 μm PP • stand up configuration: 12 μm PET/9 μm Al foil/15 μm OPA/60 μm PP The retort pouch is a space-saving package by merit of its design. It is a good substitute for tinplate cans as it eliminates the need for the addition of brine in the food. The use of retortable pouches can reduce energy consumption by about 60% during processing (Robertson, 2006). Furthermore, as the product. requires less heating to sterilise its contents, the nutritional quality and the sensory profiles for such products is higher (Krochta, 2007). The market for retort pouches is certainly one that will continue to experience growth over the next few years, as the retort pouch gains

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

697

acceptability as being equal to, or even superior to, glass or metal containers (Potter, 2008; Lagaron et al., 2008). 26.8.6 Smart packaging Innovations in the food packaging industry have created a range of new terms associated with the role of packaging in the improvement of safety, shelf-life and convenience of the packed food product (Singh and Heldman, 2009). Kerry and Butler (2008) stated that while there is no official definition of smart packaging, most would agree that it is packaging that goes beyond the use of simple packaging materials combined with traditional features such as alphanumerics, graphics and simple bar codes and can apply to primary, secondary and tertiary packaging. In the literature, this new type of packaging has been classified in many ways, such as; active, intelligent, smart, diagnostic, functional and enhanced are all terms that have been used. Kerry and Butler (2008) defined smart packaging as that which encompasses aspects of packaging design and the incorporation of mechanical, chemical, electrical and electronic forces, or combination of these, within the pack and includes packaging that is active in some way with or without communication to the users and it also includes the most common form of electronic smart packaging, radio frequency identification (RFID) enabled packaging. In the near future, the majority of consumers will be technology literate and more demanding, expecting information on packaging regarding food safety, nutrition, allergenicity, health claims, organics, genetic modification, sustainability, novel food processing, pesticide residues, additive and the ethics of food production (Butler, 2004). Consumers want packaging that saves time, is easier to open or use, and helps reduce stress in an already busy life (Butler, 2009). In order to meet this demand and future expectations, the supply of packaged cooked meat products to the consumer will be explicitly traceable through the agri-food chain, from the raw materials used through to the finished product. Traceability will be the new mantra of legislation. Central to this data driven, product-tracking network will be the development of new materials and manufacturing processes for smart packaging labels and tags using RFID – the electronic bar code. In response smart packaging is evolving in two broad fronts (Butler, 2004): • A track and trace tagged form of packaging in which smartness is conferred on the package by an electronic RFID tag or label. The major beneficiary is the supply chain, including the brand owner. • A more effectively designed and enhanced functional form of packaging in which smartness is an inherent characteristic of the package through the use of smart materials/systems or devices. The major beneficiary is the consumer and this type will be discussed in more detail in the following section.

© Woodhead Publishing Limited, 2011

698

Processed meats

The global market for active, controlled and intelligent packaging for food and beverages was worth an estimated $16.9 billion by the end of 2008. It is anticipated to reach $23.6 billion by 2013, at a compound annual growth rate (CAGR) of 6.9% (BCC Research, 2008). A wide range of smart packaging technologies have already been developed and available commercially, some of which operate successfully in packaged cooked meat and muscle-based products (Table 26.4). Smart oven is a new cooking innovation; the advanced technology of this oven combines the optimum mix of fan oven cooking with microwaves to deliver delicious food in record time. Ideal for roasting, reheating and defrosting meals for one or two, the smart oven (e.g. Samsung BCE1197) can tackle just about any type of cooking. Another advanced feature of the smart oven is the built in scanner, the smart bar code (Fig. 26.5) is used to

Table 26.4 Selected examples of smart packaging technologies (commercially available) used in processed meat products Smart packaging technology

Benefits for processed meat and muscle-based food products

Oxygen scavenger Antioxidant release Carbon dioxide emitters Antimicrobial release/coating Drip/moisture control pads Flavour/aroma emmiters Odour scavenging Time–temperature indicators

Delay oxidation of cooked meat products Inhibit or delay lipid oxidation in dried or high fat content cooked meat products Delay microbial growth and increase shelf-life of cooked meat products Inhibit microbial spoilage of cooked meat products

Freshness indicators Pathogen indicators Leak indicators Oxygen indicators Tampering indicators Product authenticity indicators

Reduce accumulation of moisture and condensation in processed meat products Enhance organoleptic properties of a wide range of cooked meat products Mask off-odours and taints in cooked meat products Provides visual evidence of the temperature history on a wide range of cooked meat products and indicates end of shelf-life Indicate the presence of chemicals associated with spoilage in cooked meat products Warn consumers of the presence of specific microbial pathogens, such as Salmonella and Listeria on cooked meat products Warn of sealing failures or physical damage to packaged cooked meat products (e.g. MAP products) Warn processors of the presence of oxygen in vacuum packaged or MAP packaged meat products Warn consumers that the pack may have been tampered or opened before purchase Distinguish genuine high value products from counterfeit items

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

699

Fig. 26.5 Ready meal packaging (Marks and Spencer plc) containing a SmartCode for use with a smart oven.

swipe over the scanner of the smart oven. Once scanned, the smart oven reads bar code information from packaged meals, adjusting cooking time and temperatures accordingingly.

26.8.7 Packaging with enclosed free-oxygen scavenging agent Cooked meat products or cook–chill convenience-style, muscle-based foods are oxygen-sensitive chemical entities and for this reason, these products are usually stored under some form of vacuum or in MAP using a gas mixture of 60–80% N2 : 20–40% CO2 (Mullan and McDowell, 2003; Hogan and Kerry, 2008). These products provide an excellent substrate for microbial growth, allowing contaminant bacteria to proliferate rapidly while conditions, particularly temperature and the gaseous environment, remain favourable. Such microbial growth will eventually cause spoilage and can also pose a health hazard (Nychas and Eleftherios, 2000). Vacuum packaging and MAP techniques do not always facilitate complete removal of oxygen (Vermeiren et al., 2003). Oxygen that permeates through the packaging film or is trapped within the meat or between meat slices cannot be removed by these techniques. Therefore, by absorbing the residual oxygen using oxygen scavengers in cooked meat products that are vacuum or MAP packed, negative quality changes can be minimised (Hogan and Kerry, 2008). Oxygen scavengers are the most commercially important sub-category of active packaging for food products and the most well known takes the form of small sachets containing various iron-based powders containing an assortment of catalysts. These chemical systems often react with water supplied by the food to produce a reactive hydrated metallic reducing agent that scavenges oxygen within the food package and irreversibly converts it to a stable oxide. The iron powder is separated from the food by keeping it in a small, highly oxygen permeable sachet that is labelled ‘Do not eat’ and includes a diagram illustrating this warning (Day, 2008). Non-metallic oxygen scavengers have also been developed to alleviate the potential for

© Woodhead Publishing Limited, 2011

700

Processed meats

metallic taints being imparted to food products. Non-metallic scavengers include those that use organic reducing agents such as ascorbic acid, ascorbate salts or catechol. They also include enzymatic oxygen scavenger systems using either glucose oxidase or ethanol oxidase, which could be incorporated into sachets, adhesive labels or into packaging film surfaces, card and closure liner (Day, 2003; Suppakul et al., 2003). Ageless® (Mitsubishi Gas Chemical Co., Japan) is the most common oxygen scavenging system based on iron oxidation. These scavengers are designed to reduce oxygen levels to less than 0.1%. Other examples of oxygen absorbing sachets include ATCO® (used commercially as oxygen scavengers in pre-packed, cooked and cooked sliced meat products; Emco Packaging Systems, UK); Standa Industrie (France), FreshPax®, FreshMax® and FreshcardTM (Multisorb Technologies, Inc., USA) and Oxysorb (Pillsbury Co., USA). Cryovac® 0S2000TM polymer-based oxygen scavenging film has been developed by Cryovac Div., Sealed Air Corporation, USA. This UV lightactivated oxygen scavenging film, composed of an oxygen scavenger layer extruded into a multilayer film, can reduce headspace oxygen levels from 1% to ppm levels in 4–10 days and is comparable in effectiveness with oxygen scavenging sachets. The OS2000TM oxygen scavenging films have applications in a variety of food products including dried or smoked meat products and processed meats (Hogan and Kerry, 2008). The main advantage of using such oxygen scavengers is that they are capable of reducing oxygen levels to less than 0.01% which is much lower that the typical 0.3–3.0% residual oxygen levels achievable by MAP. Oxygen scavengers can be used alone or in combination with MAP (Day, 2003), but commercially in the cooked meat industry, it is more common to remove most of oxygen content using MAP technology and then use the oxygen scavenger to eliminate the residual oxygen present in the packaged cooked meat product. For example, Multisorb Technologies provides to the cooked meat industry a wide range of oxygen scavengers: FreshPax® (a sachet containing an oxygen scavenger blend), FreshMax® a patch or self-adhesive oxygen scavenger blend. FreshCardTM a backer card with an oxygen scavenger blend incorporated into the structure. These oxygen scavenger packets, composed of food-grade materials, removes oxygen from a package and protects packaged foods from spoilage, rancidity and mould growth while retaining colour, nutrients, texture and flavour of the cooked meat product thereby increasing the shelf-life. FreshPax® comes in a grease-proof breathable film, and is formulated differently depending on the food product and how the food is stored. FreshCard™ uses a Solid Lay-Down© process that gives the cards an extremely flat profile and prevents the active material from spilling out even if the card is cut accidentally. In addition, both sides of the FreshCard™ are available in up to four colours to act as an added marketing tool within the package and can be used to give nutritional, or recipe

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

701

information. The packets can be dispensed from Multisorb’s Active-Pak Automation equipment which features a packet spool supply system offering automated nitrogen purge with nitrogen supply and oxygen level monitoring/alarm.

26.9 Future trends Packaging is an integral part of the processing and preservation of cooked muscle-based food products, minimising spoilage of this kind of product, maintaining the initial quality and increasing the shelf-life of these products. Cooked meat product processors are continually looking for new ways to produce and maintain enhanced flavour and nutritional characteristics. Much of this can be achieved using packaging technology. The recent innovations in packaging technologies for cooked meat products have resulted in improvements in safety, convenience, shelf-life and overall quality of the packaged cooked meat products. Future developments will provide more sophisticated packaging to extend shelf-life and maintain the quality attributes of the cooked meat product. Developments in the food packaging industry will be consumer driven mostly linked to convenience, safety and quality of the contents. Incorporating these into packaged foods will be challenging. Active packaging will continue to increase its market share in the cooked meat industry, as it can deliver cost-effective spoilage and safety control for minimal environmental impact.

26.10 References al-baali, a.g. and farid, m. 2006. Sterilisation of Food in Retort Pouches. New York: Springer Science + Business Media, LLC. apme (association of plastics manufacturers europe) 2009. The compelling facts about plastics 2009 – An analysis of European plastics production, demand and recovery for 2008. Brussels: Plastics Europe. aymerich, t., picouet, p.a. and monfort, j.m. 2008. Decontamination technologies for food products. Meat Science 78: 114–129. bcc research 2008. Active, controlled and intelligent packaging for foods and beverages. Report code: F0D038B. Available from: http://www.bccresearch.com/report/ FOD038B.html [accessed July 30, 2010]. belcher, j.n. 2006. Industrial packaging developments for the global meat market. Meat Science 74: 143–148. brody, a.l. 2000. Packaging of foods. In: R.K. Robinson, C.A. Batt and P.D. Patel (Eds.), Encyclopedia of Food Microbiology (pp. 1611–1623). London: Academic Press. brown, h. and williams, j. 2003. Packaged food product quality and shelf life. In: R. Coles, D. McDowell and M.J. Kirwan (Eds.), Food Packaging Technology (pp. 65–94). Oxford: Blackwell Publishing Ltd. brown, m.h. 2000. Processed meat products. In: B.M. Lund, T.C. Baird-Parker and G.W. Gould (Eds.), The Microbiological Safety and Quality of Food. Vol. 1 (pp. 389–419). Gaithersburg, MD: Aspen Publishers, Inc.

© Woodhead Publishing Limited, 2011

702

Processed meats

butler, p. 2004. Packaging gets smarter. Product and Image Security and Data Authentication November/December: 28–29. butler, p. 2008. Consumer benefits and convenience aspects of smart packaging. In: J. Kerry and P. Butler (Eds.), Smart Packaging Technologies for Fast Moving Consumer Goods (pp. 233–245). Chichester: John Wiley & Sons, Ltd. butler, p. 2009. Smart packaging. In: K.L. Yam (Ed.), The Wiley Encyclopedia of Packaging Technology, 3rd Ed. (pp. 1124–1134). Hoboken, NJ: John Wiley & Sons, Inc. carlin, f. 2000. Microbiology of sous-vide products. In: R.K. Robinson, C.A. Batt and P.D. Patel (Eds.), Encyclopedia of Food Microbiology (pp. 1338–1344). London: Academic Press. catalá, r. and gavara, r. 2000. Plastic materials for modified atmosphere packaging. In: J.E. Lozano, C. Añon, E. Parada-Arias and G.V. Barbosa-Canovas (Eds.), Trends in Food Engineering (pp. 311–325). Lancaster, PA: Technomic Publishing Co., Inc. ciaa 2010. Data and Trends of the European Food and Drink Industry 2009. (Confederation of the Food and Drink Industries in the EU.) cobos, a. and diaz, o. 2007. Sous-vide cooking of traditional meat products: effect on the microbiology of dry-cured pork foreleg. In: A. Mendez-Villas (Ed.), Communicating Current Research and Educational Topics and Trends in Applied Microbiology, Vol. 1 (pp. 511–517). Spain: Formatex. cosgrove, m., flynn, a. and kiely, m. 2005. Consumption of red meat, white meat and processed meat in Irish adults in relation to dietary quality. British Journal of Nutrition 93: 933–942. cruz-romero, m. and kerry, j.p. 2008. Crop-based biodegradable packaging and its environmental implications. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 3:1–25. daniels, j.a., krishnamurthi, r. and rizvi, s.s.h. 1985. A review of effects of carbonic dioxide on microbial growth and food quality. Journal of Food Protection 48, 532–537. dawson, p.l. 2001. Packaging. In: A.R. Sams (Ed.), Poultry Meat Processing (pp. 73–95). Boca Raton, FL: CRC Press. dawson, p.l. and stephens, c. 2004. Poultry packaging. In: G.C. Mead (Ed.), Poultry Meat Processing and Quality (pp. 135–163). Cambridge: Woodhead Publishing Limited. day, b.p.f. 2003. Active packaging. In: R. Coles, D. McDowell and M.J. Kirwan (Eds.), Food Packaging Technology (pp. 282–302). Oxford: Blackwell Publishing Ltd. day, b.p.f. 2008. Active packaging of food. In: J. Kerry and P. Butler (Eds.), Smart Packaging Technologies for Fast Moving Consumer Goods (pp. 233–245). Chichester: John Wiley & Sons, Ltd. dixon, n.m. and kell, d.b. 1989. The inhibition by CO2 of the growth and metabolism of microorganisms. Journal of Applied Bacteriology 67, 109–136. downing, d.l. 1996. A Complete Course in Canning and Related Processes, Vol. II, 13th Ed. Cambridge: Woodhead Publishing Ltd. doyle, m. 2008. What packaging will consumers pay more for? Food and Beverage Packaging–Market Insights for Packaging Solutions. August 1. dti 1997. Consumer Safety Research: Domestic Accidents Related to Packaging, Vol. I. London: Department of Trade and Industry. emblem, a. 2000. Predicting packaging characteristics to improve shelf-life. In: D. Kilcast and P. Subramaniam (Eds.), The Stability and Shelf-life of Food (pp. 145–170). Cambridge: Woodhead Publishing Ltd. european commission directorate-general for agriculture and rural development. 2009. Prospects for agricultural markets and income in the European Union 2008–2015. europen 2009. Public report of the European Shopping Baskets first data collection on: Packaging trends for fast moving consumer goods in selected European

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

703

countries. European Organisation for Packaging and the Environment aisbl & STFI-Packforsk AB. Available from: www.europen.be/download_protected_file. php?file=179. [accessed May 15, 2010]. fao 2009. The State of Food and Agriculture. Rome, Italy: Food and Agriculture Organization. farber, j.m. 1991. Microbiological aspects of modified atmosphere packaging – a review. Journal of Food Protection 54, 58–70. fft 2009. Overview of the processed meat market in Europe. Geneva Switzerland: Food for Thought. Available at http://www.prlog.org/10357883-overview-of-theprocessed-meat-market-in-europe.html. [accessed August 12, 2010]. freedonia 2009. Report Summary: US Meat, poultry and seafood packaging market. Available from http://www.reportlinker.com/p0128714/US-Meat-PoultrySeafood-Packaging-Market.html. [accessed September 15, 2010]. gill, c.o. and penney, n. 1988. The effect of the initial gas volume to meat weight ratio on the storage life of chilled beef packaged under carbon dioxide. Meat Science 22, 53–63. gill, c.o. and tan, k.h. 1980. Effect of carbon dioxide on growth of meat spoilage bacteria. Applied and Environmental Microbiology 39, 317–319. greed, p.g. 1998. Sensory and nutritional aspects of sous vide processed foods. In: S. Ghazala (Ed.), Sous Vide and Cook–Chill Processing for the Food Industry (pp. 57–88). Gaithersburg, MD: Aspen Publishers, Inc. hanby, e. and potter, l. 2009. Modified atmosphere packaging market Europe. In: K.L. Yam (Ed.), The Wiley Encyclopedia of Packaging Technology 3rd Ed. (pp. 794–797). Hoboken, NJ: John Wiley & Sons, Inc. haugaard, v.k. and mortensen, g. 2003. Biobased food packaging. In: B. Mattsson and U. Sonesson (Eds.), Environmentally-friendly Food Processing (pp. 180–204). Cambridge: Woodhead Publishing Ltd. hogan, s.a. and kerry, j.p. 2008. Smart packaging of meat and poultry products. In: J. Kerry and P. Butler (Eds.), Smart Packaging Technologies for Fast Moving Consumer Goods (pp. 233–245). Chichester: John Wiley & Sons, Ltd. hyytia-trees, e., skytta, e., mokkila, m., kinnunen, a., lindstrom, m., lahteenmaki, l., ahvenainen, r. and korkeala, h. 2000. Safety evaluation of sous vide-processed products with respect to nonproteolytic Clostridium botulinum by use of challenge studies and predictive microbiological models. Applied and Environmental Microbiology 66: 223–229. icpe (Indian Centre for Plastics in the Environment) 2005. Packaging of meat and poultry products. Available from: www.icpeenvis.nic.in/icpefoodnpackaging/ pdfs/19_meat.pdf [accessed June 29, 2010]. jay, j.m. 2000. Modern food microbiology, 6th Ed. Gaithersburg, MD: Aspen Publishers Inc. kerry, j. and butler, p. 2008. Preface. In: J. Kerry and P. Butler (Eds.), Smart Packaging Technologies for Fast Moving Consumer Goods (pp. xv–xvi). Chichester: John Wiley & Sons, Ltd. king, n.j. and white, r. 2006. Does it look cooked? A review of factors that influence cooked meat colour. Journal of Food Science 71: R31–R40. kirwan, m.j. and strawbridge, j.w. 2003. Plastics in food packaging. In: R. Coles, D. McDowell and M.J. Kirwan (Eds.), Food Packaging Technology (pp. 174–240). Oxford: Blackwell Publishing Ltd. krochta, j.m. 2007. Food packaging. In: D.R. Heldman and D.B. Lund (Eds.), Handbook of Food Engineering 2nd Ed. (pp. 847–927). Boca Raton, FL: Taylor and Francis Group, LLC. lagaron, j.m., ocio, m.j. and fernandez, a. 2008. Improving the performance of retortable plastics. In: P. Richardson (Ed.), In-pack Processed Foods – Improving Quality (pp. 33–54). Cambridge: Woodhead Publishing Ltd.

© Woodhead Publishing Limited, 2011

704

Processed meats

lee, d.s., yam, k.l. and piergiovanni, l. 2009. Food Packaging Science and Technology. Boca Raton, FL: CRC Press. linssen, j.p.h. and roozen, j.p. 1994. Food flavour and packaging interactions. In: M. Mathlouthi (Ed.), Food Packaging and Preservation (pp. 48–61). New York: Blackie Academic and Profesional. magdelaine, p., spiess, m.p. and valceschini, e. 2008. Poultry meat consumption trends in Europe. World’s Poultry Science Journal 64: 53–63. marsh, k.s. 2009. Shelf-life. In: K.L. Yam (Ed.), The Wiley Encyclopedia of Packaging Technology, 3rd Ed. (pp. 1100–1107). Hoboken, NJ: John Wiley & Sons, Inc. marsh, k. and bugusu, b. 2007. Food packaging and its environmental impact. Food Technology 61(4): 46–50. mcconnell, v. 2004. Pack it in! Just say no to impossible packaging. Yours Magazine 30 January–27 February: 16–18. miller, r. 2005. The landscape for biopolymers in packaging. York: National NonFood Crops Centre (NNFCC). molin, g. 2000. Modified atmospheres. In: B.M. Lund, T.C. Baird-Parker and G.W. Gould (Eds.), The Microbiological Safety and Quality of Food, Vol. 1 (pp. 214– 234). Gaithersburg, MD: Aspen Publishers, Inc. mullan, m. and mcdowell, d. 2003. Modified atmosphere packaging. In: R. Coles, D. McDowell and M.J. Kirwan (Eds.), Food Packaging Technology (pp. 303–339). Oxford: Blackwell Publishing Ltd. nissen, h., rosnes, j.t., brendehaug, j. and kleiberg, g.h. 2002. Safety evaluation of sous vide-processed ready meals. Letters in Applied Microbiology 35: 433–438. nychas, g-j.e. and eleftherios, h. 2000. Spoilage of meat. In: R.K. Robinson, C.A. Batt and P.D. Patel (Eds.), Encyclopedia of Food Microbiology (pp. 1253–1260). London: Academic Press. o’grady, m.n. and kerry, j.p. 2008. Smart packaging and their application in conventional meat packaging systems. In F. Toldrá (Ed.), Meat Biotechnology (pp. 425– 451). New York: Springer Science + Business Media, LLC. parking, k.l. and brown, w.d. 1982. Preservation of seafood with modified atmospheres. In: R.E. Martin, G.J. Flick, C.E. Hebard and D.R. Ward (Eds.), Chemistry and Biochemistry of Marine Food Products (pp. 453–465). Westport, CT: AVI Publishing. parry, r.t. 1993. Introduction. In: R.T. Parry (Ed.), Principles and Applications of Modified Atmosphere Packaging of Food. Glasgow: Blackie Academic & Profesional. pbi-dansensor. 2010. A guide to MAP gas mixtures. Available from: www.pbi-dansensor.com [accessed July 1, 2010]. pearson, a.m. and guillet, t.a. 1996. Processed Meats, 3rd Ed. New York: Chapman & Hall. peck, m.w. and stringer, s.c. 2005. The safety of pasteurised in-pack chilled meat products with respect to the foodborne botulism hazard. Meat Science 70: 461–475. potter, l. 2008. Retortable pouches. In: P. Richardson (Ed.), In-pack Processed Foods–Improving Quality (pp. 17–32). Cambridge: Woodhead Publishing Ltd. rexam 2009. Annual Report 2009. Available from: www.rexam.com/ar09 [accessed June, 2010]. robertson, g.l. 2006. Food Packaging – Principles and Practice, 2nd Ed. Boca Raton, FL: CRC Press. robertson, g.l. 2009. Packaging of food. In: K.L. Yam (Ed.), The Wiley Encyclopedia of Packaging Technology, 3rd Ed. (pp. 891–898). Hoboken, NJ: John Wiley & Sons, Inc. rodgers, s. 2004. Novel approaches in controlling safety of cook–chill meals. Trends in Food Science and Technology 15: 366–372.

© Woodhead Publishing Limited, 2011

Packaging of cooked meats

705

rombouts, f.m., notermans, s.h.w. and abee, t. 2003. Food preservatives – future prospects. In: N.J. Russell and G.W. Gould (Eds.), Food Preservatives (pp. 348– 370). New York: Kluwer Academic/Plenum Publishers. shapton, d.a. and shapton, n.f. 1993. Safe Processing of Foods. Oxford: Butterworth-Heinemann Ltd. singh, r.p. and heldman, d.r. 2009. Introduction to Food Engineering, 4th Ed. London: Academic Press. sivertsvik, m., rosnes, t. and bergslien, h. 2002. Modified atmosphere packaging. In: T. Ohlson and N. Bengtsson (Eds.), Minimal Processing Technologies in the Food Industry (pp. 61–86). Cambridge, UK: Woodhead Publishing Ltd. spencer, k.c. 2005. Modified atmosphere packaging of ready-to-eat foods. In: J.H. Han (Ed.), Innovations in Food Packaging (pp. 185–203). Oxford: Elsevier Academic Press. stöllman, u., johansson, f. and leufvén, a. 2000. Packaging and food quality. In: C.M.D. Man and A.A. Jones (Eds.), Shelf-life Evaluation of Foods (pp. 42–56). Gaithersburg, MD: Aspen Publishers Inc. suppakul, p., miltz, j., sonneveld, k. and bigger, s.w. 2003. Active packaging with emphasis on antimicrobial packaging and its implications. Journal of Food Science 68: 408–420. thippareddi, h. and sanchez, m. 2006. Thermal processing of meat products. In: D-W. Sun (Ed.), Thermal Food Processing: New Technologies and Quality Issues (pp. 155–196). Boca Raton, FL: CRC Press. trostle, r. 2008. Global agricultural supply and demand: factors contributing to the recent increase in food commodity prices. WRS-0801 Economic Research Service/ USDA. Available from: http://www.ers.usda.gov/Publications/WRS0801/ WRS0801.pdf [accessed August 15, 2010]. troy, d.j. and kerry, j.p. 2010. Consumer perception and the role of science in the meat industry. Meat Science 86: 214–226. tucker, g. 2006. Thermal processing of ready meals. In: D-W. Sun (Ed.), Thermal Food Processing: New Technologies and Quality Issues (pp. 363–385). Boca Raton, FL: CRC Press. tung, m.a. britt, i.j. and yada, s. 2001. Packaging considerations. In: N.A.M. Eskin and D.S. Robinson (Eds.), Food Shelf-life Stability: Chemical, Biochemical and Microbiological Changes (pp. 129–145). Boca Raton, FL: CRC Press LLC. verghese, k. 2008. Environmental assessment of food packaging and advance methods for choosing the correct materials. In: E. Chiellini (Ed.), Environmentally Compatible Food Packaging (pp. 182–210). Cambridge: Woodhead Publishing Ltd. vermeiren, l., heirlings, l., devlieghere, f. and debevere, j. 2003. Oxygen, ethylene and other scavengers. In: R. Ahvenainen (Ed.), Novel Food Packaging Techniques (pp. 22–49). Cambridge: Woodhead Publishing Ltd. winder, b. 2006. The design of packaging closures. In: N. Theobald and B. Winder (Eds.), Packaging Closures and Sealing Systems (pp. 36–67). Oxford: Blackwell Publishing Ltd. wpo 2008. Position paper – Market trends and developments. World Packaging Organisation. xiong, y.l. and mikel, w.b. 2001. Meat and meat products. In: Y.H. Hui, W-K. Nip, R.W. Rogers and O.A. Young (Eds), Meat Science and Applications (pp. 351–369). New York: Marcel Dekker, Inc. yam, k.l. 2009. Packaging functions and environments. In: K.L. Yam (Ed.), The Wiley Encyclopedia of Packaging Technology, 3rd Ed. (pp. 869–871). Hoboken, NJ: John Wiley & Sons, Inc. zagory, d. 1997. Modified atmosphere packaging. In: A.L. Brody and K.S. Marsh (Eds.), The Wiley Encyclopedia of Packaging Technology, 2nd Ed. (pp. 650–656). New York: John Wiley & Sons, Inc.

© Woodhead Publishing Limited, 2011

Index

ABSO2RB, 469 accessibility, 32 acrylamide, 366 Activa, 272, 273, 277, 282, 283, 285, 288, 455, 461, 462 active packaging, 443 actomyosin, 597 AD–080CL camera, 557–8 additives, 147–8 adhesion batters, 640 aerobic packaging, 122 Ageless, 700 Agreement on Application of Sanitary and Phytosanitary Measures, 55–6 Agreement on Technical Barriers to Trade, 55–6 air cycle refrigeration, 586 albumin, 219 Alcalase, 229, 230 alginate, 257, 277–9 alginate (E401), 61 allergen labelling, 144–5 allicin, 311 American Association of Analytical Communities (AOAC), 92 American Dietetic Association, 36–7 American Meat Industry (AMI), 80 American Meat Science Association (AMSA), 158 angiotensin converting enzyme (ACE), 230 antibody agglutination test, 84 antimicrobials, 388 antioxidants, 122 APIS Spektron Meat Optimiser, 548 aqueous model systems, 117 aqueous wood smoke see liquid smoke

aroma appeal, 467–9 Association Français de Normalisation (AFNOR), 92 ATCO, 700 atomisation, 533–6 calibration of deluxe panel, 536 maintenance of units, 536–8 cleaning the atomisation nozzle, 537 cleaning the POWRSMOKER, 537–8 vaporous cloud produced by atomisation nozzle, 536 bacteriocins, 302, 304–10 enterocins and meat manufacturing, 306–8 nisin, 304–5 novel bacteriocins and innovative alterations in meat processing, 308–10 other bacteriocins and their use in meat processing, 306 Bacteriological Analytical Manual (BAM), 77 Bactoferm Rubis, 467 batter, 640 BAX Screening System, 78, 92 BCM0 listeria monocytogenes plating medium, 78 Beef Steak & Pepper and Homestyle Beef, 452 benzpyrene fraction, 482 beta glucan, 255–6 Better Training for Safer Food, 66 biaxially oriented polyamide (BOPA), 684 Bifidobacterium, 404 bind coefficients, 197 bind indices, 197

© Woodhead Publishing Limited, 2011

Index bind values, 197 binders, 432–4 binding, 621 bioactive ingredients, 229–32 biogenic amines (BAs), 483–8 characterisation, 483, 485 precursors and amines and polyamines, 485 determination, 487–8 occurrence in meat and meat products, 488, 489–90 content, 489–90 technological effects on content, 487 toxicological considerations, 485–7 Bioquell, 115 Black Angus Ranch Roast Beef, 452 blended meat products scientific modelling, 185–215 advanced application issues, 212–14 least-cost formulation model, 190–6 linear science-based models for meat products properties, 196–207 solving the least-cost formulation – science-based formulation problem, 208–12 blood applications, 223–32 techno-functional ingredients, 223 bioactive ingredients, 229–32 blood-derived peptides antimicrobial potential, 231–2 bioactive peptides source and other healthy components, 229–31 by-products as ingredients in processed meats, 218–33 characterisation, recovery and processing, 218–23 driving forces for blood utilisation, 218–19 physical and chemical properties and its fractions, 219–20 processing to prevent microbial spoilage, 222–3 recovery from slaughterhouses, 220–1 future trends, 232–3 plasma and its derivatives, 226–9 plasma protein fractions, 227–9 RBC and its derivatives, 223–6 globin, 224–5 globin hydrolysates, 225 Hb as natural red colourant, 225–6 blood plasma, 219 blood protein, 253 boil cooking packaging, 692–4 bovine plasma, 230 bovine spongiform encephalopathy (BSE), 280

707

braising, 618–19 breading, 640–1 brine injection, 543 brines, 423, 427 broiling, 619 buffered peptone water, 91 Butcher & Cook, 452 CAF see computer-assisted formulation calcium carbonate, 278, 279 Campylobacter jejuni, 604 canola oil, 351, 354 carbohydrates, 253–9 animal origin, 258–9 chitosan, 258–9 plant origin, 253–8 alginate, 257 beta glucan, 255–6 carrageenan, 254–5 cellulose, 254 galactomannan, 256–7 konjac glucomannan, 256 pectin, 257–8 starch, 253–4 carnosine, 42 carrageenan (E407), 61 carrageenan gum, 254–5, 350, 356 caseinates, 251–2 Cells Alive System (CAS) freezing, 585 cellulose, 254, 530 Centre for Disease Control and Prevention, 65 Charsol, 531 Cheddar cheese, 303 chemical binding, 271 Chiba Flour Mills, 272, 284 chilling impact on processed meat quality, 576–7 impact on processed meat safety, 571–6 chitosan, 258–9 CHROMagar0, 78 chub pack, 687 claims rules, 137–46 allergen labelling, 144–5 common ingredients in meat products, 145 beef and veal labelling, 140–2 maximum fat and connective tissue contents, 141 compulsory labelling indications, 145 food labelling directive, 138–9 hygiene labelling, 146 lot marking, 139 meat products origin marking, 139–40 nutrition and health claims, 143–4 nutrition labelling, 142 protected food names, 145–6

© Woodhead Publishing Limited, 2011

708

Index

ClassicRoast, 468 CLITRAVI, 142 Clostridium botulinum, 604 Clostridium perfringens, 604 Codex Alimentarius, 56, 73, 151–2 influence, 152 cold-set binders, 276–85 advantages, 290–1 alginate system as a cold-set meat binder, 277–9 beef roll using ground meat and alginate binding system, 277 binder comparisons, 288–9 cooked restructured beef steakettes effect of binder and size reduction method, 287 effect of size reduction method and size of machine opening, 288 fibrin/thrombin system as a cold-set meat binder, 280–2 fibrimex binding based on the blood clotting cascade, 280 ingredients in conventionally restructured meat products, 274–5 phosphates, 275 salt, 274–5 seasonings and flavourings, 275 meat source, 272–4 fresh vs frozen vs pre-rigor meat, 273–4 muscle selection, 272–3 particle size reduction, 285–8 protein compounds as cold-set meat binders, 284–5 restructured meat products quality control, 291–5 appearance, 292 flavour, 293–4 texture, 292–3 restructuring advantages, 289–90 traditional restructured meat products, 274–6 mechanical action, 275–6 transglutaminase enzymes as cold-set meat binders, 282–4 use in meat systems, 270–95 specialty restructured meat product, 271 Colloidal Liquid Clearing Concentrate, 315 colorectal cancer, 68–9 ColourTrend, 553 Commission Directive 88/388/EC, 482 Commission Directive 2001/101/EC, 58–9 Commission Directive 2005/10/EC, 481 Commission Recommendation 2005/108/EC, 481 Commission Regulation 1881/2006/EC, 481 Commission Regulation 2065/2003/EC, 482 Commission Regulation No. 1825/20001, 59

computer-assisted formulation, 186–7 conduction, 567–8, 624 conduction-based systems, 629–30 ConSense approach, 167–71, 173 overall dynamics of strategy, 171 preference mapping, 170 stages of development, 168 consumer demands determinates of consumer demand, 5–16 Bangladesh and Hongkong income elasticity, 11, 12 beef exports from US, 8 Canadian beef exports, 15 consumer incomes, 9–12 demand changes, 8 lamb exports from US, 9 meat consumption in China and Ireland, 10 meat demand quantity changes, 6 population changes, 13–14 population dynamics of France and Canada, 14 pork exports from US, 9 price and quantity demand, 5–12 price elasticity demand, 7 substitutes price and complements, 13 supply determinates, 14–15 taste and preferences, 12–13 total food expenditures, 7 meat consumption patterns, 16–26 America, 16–19 Asia, 23–5 Australia and New Zealand, 25–6 Europe, 19–23 general rules, 25–6 and regional preferences for meat, 3–29 effect of choice, 5 effect of taste, 4–5 future trends, 26–9 consumer-led processed meat products sensory science use, 156–77 case studies, 173–5 future trends, 166–71 sensory-based methodologies and approaches, 162–6 sensory-based quality control past and present status, 157–62 successful consumer processed meat products, 172–3 consumer trends, 34–7 convenience, 34–5 type and timing combinations, 35 processed meat products, 30–49 wellness, 35–7 contaminants, 148–51 herbicide, 148–51

© Woodhead Publishing Limited, 2011

Index pesticide, 148–51 processed meat products, 478–500 biogenic amines, 483–8 heterocyclic amines, 495–9 N-nitroso amines, 488–94 polycyclic aromatic hydrocarbons, 478–83 veterinary residues, 148–51 contamination listeriosis, salmonellosis and verocytotoxigenic E. coli in processed meats, 72–93 Escherichia coli, 78–85 Listeria monocytogenes, 73–8 Salmonella, 85–92 convection, 569, 624 convection-based systems, 630–42 forced air convection, 631–4 airflows within a static oven system employing damper systems, 633 static roll on, roll off oven system with microprocessor controls, 632–3 free air convection, 630–1 frying, 639–42 impingement cooking, 634–8 ECHO impingement oven installation, 637 impingement jet tube array showing collimated air movement, 635 typical ECHO continuous impingement pasteurisation line, 635 sous vide cooking, 639 water immersion systems, 638–9 convenience, 451, 469–70 convenience foods, 34–5 convenience meat products aesthetics-related quality problems in whole-tissue products, 455–7 cured colour fading, 458–9 exudates in pre-packaged pre-sliced meats, 459–60 iridescence, 459 iridescence in sliced beef pastarma, 460 pink defect in cooked meats, 458 improving quality, 450–72 convenience, 469–70 examples, 453, 454 flavour and aroma appeal, 467–9 future trends, 470–2 oral appeal, 466–7 visual appeal, 463–6 whole-tissue meats, 451–3 quality issues, 453–5, 458–63 flavour and odour-related, 461–2 loss of convenience, 462–3 texture/tenderness-related, 460–1

709

convenience-style meat products, 666–701 convenience whole-tissue meats, 451–3 cooked ham, 601 cooked meat packaging, 666–701 Council Directive 77/99/EC, 220 Council Directive 94/65/EC, 59 Council Directive 77/99/EEC, 59 credence qualities, 31 crust freezing, 583–4 cryogenic chilling, 569 Cryovac Darfresh, 470, 676 Cryovac 0S2000, 700 CSIRO Total Wellbeing Diet, 36 CuliDish, 470 culinology, 620 curdlan, 260 cured colour, 458–9 cured meat products improving sensory quality, 508–19 basis for colour and texture development, 515–16 biochemical basis of flavour development, 509–15 processing factors affecting sensory quality, 516–17 trends to accelerate the processes and/ or improve the sensory quality, 517–19 Dawn Meats, 452 deep-chilled, 583 deep-frying, 619 Deli Roast Beef, 452 deoxyhaemoglobin, 219 descriptive analysis, 164–5 Destron PG-100, 554 developed nations, 26 developing nations, 26 3-DEX, 692–3 diagnosticity, 32 direct addition, 543 Directive 1990/496, 142 Directive 2000/13, 138, 147 Directive 2003/89, 144 Directive 2008/5, 145 Directive 95/2/EC, 151 Directive 98/6/EC, 138–9 Directive 98/72/EC, 248 Directive 2000/13/EC, 64 Directive 2000/101/EC, 141 Directive 2005/10/EC, 481 Directive 2006/52/EC, 151 Directive 88/388/EEC, 482 Directive 89/396/EEC, 139 Directive 95/2/EU, 245, 248, 254, 260 double packaging, 122–3

© Woodhead Publishing Limited, 2011

710

Index

drenching, 538–43 advantages over atomisation, 538 factors that affect the success, 541 smoke acidity determination, 542 smokehouse schedule development, 542 dry-cured ham, 510–11 processing, 338–9 trends to accelerate process and improve sensory quality, 517–19 water activity in external muscle, 511 water activity levels on muscle cathepsins and calpain, 512 dry-fermented sausages proteolysis, 511–13 trends to accelerate process and improve sensory quality, 519 dry marinades, 435–6 dual energy X-ray systems, 549 DuPont lateral flow system, 78 e-beam irradiation, 112–13 Eagle Bulk 370 X-ray, 560 EAGLE FA 720, 549 EC 1003/2005 Regulation, 87 EC 2160/2003 Regulation, 87 EC Meat Products Directive, 572 EC Regulation 852/2004, 571 ECHO CT-100, 651, 654 elastomeric polymer, 684 electronic nose (E-nose), 161–2 emerging markets, 45–7 categories of newly launched products with meat ingredients, 48 growth in processed meat sales, 47 ongoing consumer trends, 34–7 convenience, 34–5 wellness, 35–7 positioning strategies, 37–45 ethical buying types, 38 ethical positioning, 37–9 ethically positioned meat products, 40 food and beverages containing meat ingredients, 41 functional meat products, 39–42 meal solutions, 43–5 reduced-fat and reduced-salt products, 42–3 processed meat products, 30–49 consumer judgement on meat quality, 31–3 emulsification theory, 622 en papilotte cooking, 618 endoproteases, 512 Engel’s Law, 45 ENIAC computer, 188 EnterNet, 65, 81 enterocins, 306–8

enzyme modified potato starch, 359 Escherichia coli, 78–85 contamination routes and control regulations, 79–81 detection methods, 84–5 VTEC incidence in processed meats, 81–4 E. coli O157:H7 outbreaks, 83 VTEC serotypes, 79 Escherichia coli O157:H7, 604 essential oils, 301, 310, 385–6 oregano, 311–13 thyme, 311 ethical consumption, 37–8 ethical positioning, 37–9 buying, consumer behaviour and consequences for food industry, 38 samples of products, 40 ethylene vinyl alcohol (EVOH), 684 EU Regulation 1924/2006, 57 European Centre for Disease Prevention and Control, 73 European Commission’s Food and Veterinary Office, 57 European Economic Area (EEA), 57 European Food Law Association, 151 European Food Safety Authority (EFSA), 61, 62–3, 301, 304 European Parliament and Council Regulations 1760/2000, 59 European Union general food law regulation, 136–7 consumers interest protection, 136–7 quality schemes, 137 responsibilities, 136 traceability, 136 processed meat labels regulation, 134–54 Codex Alimentarius, 151–2 food information provision to consumers, 152–3 food law regulation, 136–7 information sources and advice, 153–4 labelling and claim rules, 137–46 other measures, 147–51 evaporation, 568 expanded polystyrene (EPS), 684 experience qualities, 31 fat, 598 fat hardness, 354 Fat-O-Meat’er, 554 fat reduction alternative fat-replacing ingredients, 355–65 fat, starch, and egg white levels on hardness on bologna sausage, 362 processed meat products, 346–66 consequences, 349–50

© Woodhead Publishing Limited, 2011

Index future trends, 365–6 importance, 346–7 role of fat, 347–9 technological methods, 350–1 saturated fat replacement, 351–5 fat and fluid losses from meat batters, 352 fat replacement, 355–65 FCP see free choice profiling fermented meat products improving sensory quality, 508–19 biochemical basis of flavour development, 509–15 fermented sausage, 601–2 Fibrimex, 272, 277, 280, 287, 288, 461, 462 fibrinogen, 220 flash profiling, 164, 166 Flash stick, 561 Flavorlean, 468 flavour, 595–6 flavour appeal, 467–9 flavour development, 653 flavourings, 275, 434–5 Flir ThermaCAM, 559 fond, 619 food additives, 147–8 functional classes, 149–50 Food and Agricultural Organisation (FAO), 151 food business operator, 63, 173 food code see Codex Alimentarius food grade sanitisers, 315 food information provision, 152–3 further delay, 153 nutrition labelling, 153 origin labelling, 153 food irradiation processed meat products, 109–123 approval in the US, 111 future trends, 123 irradiation effects on meat quality, 114–21 pathogen control, 111–14 quality changes prevention, 121–3 food labelling directive, 138–9 food packaging, 44–5 processed meat products and smart packaging, 46 food safety, 558–62 advances in foreign object detection, 561–2 fluorescence, 561 food freshness, 562 future trends, 561–2 HACCP plan for sausage making, 560 IR imaging, 558–60

711

natural and novel antimicrobials in processed meat products, 299–320 advantages and new perspective for application, 316–20 combined effect with other barriers, 313–15 food grade sanitisers, 315 range for food application, 301–13 objective, 113 online techniques, 558–61 processed meats, globalisation and challenges, 54–70 nutrition, 68–9 temperature calculated with Mikron 7302, 559 trade liberalisation, 55–68 European import rules, 56–7 logistics and transport, 62–3 microbial load as quality cues, 63–4 processed meat labelling and traceability, 57–62 procurement policies, 66–8 surveillance systems, 64–6 X-rays, 560–1 Food Safety Authority of Ireland, 73, 373 Food Standard Agency, 140, 142, 247 food technologies, 44 FoodNet, 73 Foodproof salmonella, 92 foods for specified health use (FOSHU), 316, 411 FoodScan, 548 forced air convection, 631–4 airflows within a static oven system employing damper systems, 633 static roll on, roll off oven system with microprocessor controls, 632–3 FORTRAN, 188 FOSHU see foods for specified health use free air convection, 630–1 free choice profiling, 165 freezer-burn, 581 freezing, 569 impact on processed meat quality, 580–1 impact on processed meat safety, 576 FreshCard, 700 FreshMax, 700 FreshPax, 700 frying, 639–42 FSA see Food Standard Agency FSA method, 142 functional foods, 373 functional meat products, 39–40 health and wellness-positioned foods and beverages containing meat ingredients, 41 functional starter cultures (FSC), 318

© Woodhead Publishing Limited, 2011

712

Index

galactomannan, 256–7 gamma-ray irradiation, 112–13 garlic, 310–11 gas chromatography mass spectrometry (GC/MS), 161 gelatin, 252–3 gellan gum, 259–60 General Agreement on Tariffs and Trade, 55 General Standard for the Labelling of Prepackaged Foods, 152 generally recognised as safe, 252, 300 genetically modified (GM) ingredients, 148 genetically modified organisms, 61, 319 geometric centre, 625 global cuisine range, 676 globulins, 219–20 glucono-delta lactone (GDL), 278 glycolysis, 513–14 GMO see genetically modified organisms grilling, 619 guided microwave spectroscopy (GMS), 549 gums, 355–6 haemoglobin, 219 hazard analysis and critical control points, 63, 253, 558 health claims, 143–4 health positioning, 42–3 Health Protection Agency, 65 Health Protection Surveillance Centre, 73 ‘Heat n’ Serve,’ 470, 676, 677 heated belt-direct contact cooking systems, 629–30 hemicellulose, 530 Hennessy grading probe, 554 herbs, 385 heterocyclic amines (HAs), 495–9 analysis, 497, 499 characterisation, 495, 496 names and abbreviations, 496 formation and elimination, 497, 498 findings in meat products, 498 imidazoquinoline, imidazoquinoxaline and imidazopyridine formation, 495, 496–7 pyridoindole and pyridoimidazole compound formation, 497 high density lipoprotein (HDL), 351 high hydrostatic pressure (HHP), 222, 314, 590–1 high-impact polystyrene (HIPS), 684 high pressure freezing, 585 high pressure-induced transformation (Hi-Pit), 591 high pressure jam, 591 high pressure processing, 44, 443

high pressure technology advances in application to processed meat products, 590–609 effect on meat and meat products quality, 592–6 flavour, 595–6 lipid oxidation, 593–5 meat colour, 592–3 WHC, 592 future trends, 606, 609 HHP products in the market, 607–8 microbial control in meat and meat products, 603–5 new applications in meat industry, 606 high pressure freezing and thawing, 606 natural casing improvement, 606 pressure-processed meat products, 596–603 cooked ham, 601 development of products as healthy food, 597–601 fermented sausage, 601–2 meat products for dysphagia diet, 603 pressure-induced gelation of muscle proteins, 596–7 pressure pre-cooked meat products, 602–3 raw ham-like meat product, 602 home meal replacements (HMR), 43 hydrocolloids application, 249–62 carbohydrates of animal origin, 258–9 chitosan, 258–9 carbohydrates of plant origin, 253–8 alginate, 257 beta glucan, 255–6 carrageenan, 254–5 cellulose, 254 galactomannan, 256–7 konjac glucomannan, 256 pectin, 257–8 starch, 253–4 enzymes, 260–1 transglutaminase, 260–1 future trends, 262–4 hydrocolloids application in processed meats, 263 meat matrix, 245–6 typical meat emulsion, 246 microbial hydrocolloids, 259–61 curdlan, 260 gellan gum, 259–60 xanthan, 259 miscellaneous ingredients, 261–2 maltodextrin, 262 sugars, 261–2 origin of different types used in food industry, 244

© Woodhead Publishing Limited, 2011

Index proteins of animal origin, 251–3 blood protein, 253 caseinates, 251–2 gelatin, 252–3 whey protein, 251 proteins of plant origin, 250–1 soy protein, 250 wheat gluten, 250–1 utilisation in processed meat systems, 243–64 challenges faced by the meat industry today, 247–8 regulation and scrutiny concerning usage in processed meats, 248–9 hydroxyl radicals, 116 hygiene labelling, 146 ‘Hyo-on,’ 583 HySpex, 557 IBM, 188 iLabel verification system, 556 immersion, 436–7 impingement cooking, 634–8 ECHO impingement oven installation, 637 impingement jet tube array showing collimated air movement, 635 typical ECHO continuous impingement pasteurisation line, 635 impingement jets, 636 impingement technology, 586 ImSpector, 557 InAlyzer system, 549 infeasible, 210 infective dose, 74, 86 information services (IS), 213 infrared cooking, 642–3 general frequency bands and wavelengths, 643 injection processing, 437 internal addition brine injection, 543 direct addition, 543 International Office of Epizootics, 56 ionomers, 683 IRB 340 FlexPickers, 556 iridescence, 459, 460 irradiation effects, 114–21 meat quality, 114–21 volatile compounds and odor characteristics, 118 Ishida IX–GA–2475 X-ray machine, 560 ISO (1992), 165 ISO (1994), 165 IVC-3D smart camera, 556 JECFA see Joint FAO/WHO Expert Committee on Food Additives

713

Joint FAO/WHO Expert Committee on Food Additives, 248 Joule heating see ohmic heating Karoolamb shanks, 452 KCl see potassium chloride KELCOGEL, 260 KELCOGEL F, 260 KELCOGEL LT, 260 KELCOGEL LT100, 260 Kelpac, 277 Keltrol F xanthan gums, 259 Kerry Ingredients, 468 konjac flour, 357 konjac glucomannan, 256 Kung-wan, 353, 357 L. monocytogenes, 111–12 L-glutamate, 4–5 LAB see lactic acid bacteria L*a*b* colour space, 553 lactic acid bacteria, 222, 299, 302–3 Lactobacillus, 404 Lactobacillus gasseri, 407 Lactobacillus rhamnosus strain GG, 405, 407 Lactococcus lactis DPC4268, 303 lactose broth, 91 Lappin-Clark procedure, 531 LCF see least cost formulation least cost formulation, 168–9, 186–96 advanced application issues, 212–14 cost, 213–14 inventories, 213 multicomponent formulation, 213 multiproduct formulation, 213 reverse-engineering formulae using LCF and SBF, 214 central assumptions, 190–2 conservation, 191 continuity, 192 linearity, 191–2 history in meat industry, 187–90 model, 190–6 availabilities, 195–6 prices, 195 product formula input–output model, 193–5 other process effects, 194–5 shrink loss or gain, 193–4 Least Cost Formulations, Ltd., 199 Least Cost Formulator, 199, 205 LightCycler foodproof E.coli 0157:H7 detection kit, 85 LightCycler foodproof Listeria genus detection kit, 78 lignin, 530

© Woodhead Publishing Limited, 2011

714

Index

linear science-based models crude chemistry (proximate analysis), 199, 200–1 list of sample set of materials, 200–1 functional attributes, 202, 205, 206–7 lists estimated functional attributes for sample materials, 206–7 meat products properties, 196–207 compositional groupings (logical relationships), 199 flavour attributes, 205 mixture models, 197–9 physical attributes, 205 nutritional content, 202, 203–4 sample materials, 203–4 lipid oxidation, 378–81, 461–2, 593–5 lipolysis, 513, 514 major steps and oxidations to flavour compounds, 514 liquid smoke, 527, 529 critical components of condensate, 530–1 acids, 530 aromatic hydrocarbons, 531 carbonyls, 531 phenolics, 530–1 liquid smoke flavours, 482 Lister test, 78 Listeria monocytogenes, 73–8, 604 contamination routes and control regulations, 75 detection methods, 77–8 incidence, processed meats, 76–7 outbreak due to RTE foods, 77 incubation period, 74 Listeria VIA, 78 lithium-chloride-phenylethanol-moxalactam agar, 77 loop-mediated amplification (LAMP), 85 LuraLean, 466 MacConkey agar, 84–5 magnetic resonance freezing, 585 Maillard reaction, 636 maltodextrin, 262, 357–8 Marel Food Systems INS 2000 Vision Slicer, 555 marinate, 423 marinating absorption and retention, 427–9 phenomenon during marinating and cooking, 429 established effects, 438–41 flavour enhancement, 438–9 meat colour, 440–1 processing yields, 440 tenderness, 439–40

functional ingredients, 429–35 binders, 432–4 effect of marinating time and marinade pH, 433 organic acids, 431–2 phosphates, 430–1 salt, 430 spices and flavourings, 434–5 water, 431 methods of marinade delivery, 435–8 dry marinades, 435–6 immersion processing, 436–7 injection processing, 437 paste marinades, 436 tumbling and massaging, 437–8 nutritional content enhancement of processed meat products, 421–43 commercially available Indian and Chinese marinades and sauces, 422 future research, 442–3 overview and terminology, 423–7 recently published journal articles, 424–6 sensory evaluation, 441–2 correlation loadings plot, 442 masking agents, 340 massaging, 437–8 materials requirements planning (MRP), 213 maximum residue limits (MRLs), 151 McLean Delux, 350 meal solutions, 43–5 meat consumer demands and regional preferences, 3–29 choice effect, meat consumption, 5 consumer determinants, 5–16 future trends, meat consumption, 26–9 meat consumption patterns and economic data, 16–26 taste effect, meat consumption, 4–5 meat colour, 440–1, 592–3 meat composition and attributes, 547–52 meat consumption, 16–26 Americas, 16–19 consumption and selected demographic data for Brazil, 18 consumption and selected demographic data for Canada, 17 consumption and selected demographic data for Mexico, 18 consumption and selected demographic data for the United States, 17 Asia, 23–5 consumption and selected demographic data for China, 23 consumption and selected demographic data for Japan, 24

© Woodhead Publishing Limited, 2011

Index consumption and selected demographic data for South Korea, 24 Australia and New Zealand, 25–6 consumption and selected demographic data for Australia, 25 consumption and selected demographic data for New Zealand, 26 choice effect, 5 Europe, 19–23 consumption and selected demographic data for France, 20 consumption and selected demographic data for Germany, 21 consumption and selected demographic data for Ireland, 21 consumption and selected demographic data for Russia, 22 consumption and selected demographic data for Spain, 22 consumption and selected demographic data for United Kingdom, 20 future trends, 26–9 world meat consumption, 27 general rules for all countries, 25–6 patterns and economic data, 16–26 taste effect, 4–5 Meat Descriptive Attribute Method, 157 meat fermentation probiotics, 405–8 meat industry, 37–45 challenges, 247–8 positioning strategies, 37–45 ethical buying types, 38 ethical positioning, 37–9 ethically positioned meat products, 40 food and beverages containing meat ingredients, 41 functional meat products, 39–42 meal solutions, 43–5 reduced-fat and reduced-salt products, 42–3 meat labelling regulation for processed meat in the European Union, 134–154 Codex Alimentarius, 151–2 food information provision to consumers, 152–3 food law regulation, 136–7 information source and advice, 153–4 labelling and claim rules, 137–46 other measures, 147–51 meat products probiotics and prebiotics, 403–13 concept of probiotics, prebiotics and synbiotics, 411 future trends, 411–13

715

meat protein-derived prebiotic peptides, 409–10 prebiotics, 408–9 prebiotics and meat products, 410–11 probiotics, 404–5 probiotics and meat fermentation, 405–8 Meat Products (Hygiene) Regulations (1994), 572 meat quality, 31–3 irradiation effects, 114–21 quality changes prevention, 121–3 meat systems cold-set binders, 270–95 advantages, 290–1 binder comparisons, 288–9 cold-set binders, 276–85 meat source, 272–4 particle size reduction, 285–8 restructured meat products quality control, 291–5 restructuring advantages, 289–90 traditional restructured meat products, 274–6 Med-Vet-Net, 65 Meypro-Guar, 257 Meyprodor, 257 Meyprodyn, 257 MeyproFleur, 257 Meyprotin, 257 microbial load, 63–4 microbial safety nutraceuticals, 384–90 combination strategies, 388–90 microorganism-derived antimicrobials, 388 plant origin, 385–7 microbial spoilage, 222–3 microwave, 643–8 continuous microwave system outline, 647 critical process factors in microwave heating, 648 frequencies assigned by FCC for industrial, scientific and medical use, 644 Mikron 7302 microbolometer camera, 559 Minolta CR-210 colorimeter, 553 Mintel GNPD database, 39, 43, 45 Miscellaneous Additives Directive (MAD), 248 mixture models, 197–9 MM710 Backscatter Sensor, 548 modified atmosphere packaging, 443, 689–92, 693 gas mixtures used in MAP, 691 processed meat products packaged under MAP, 693 modified Gibbs procedure, 531

© Woodhead Publishing Limited, 2011

716

Index

moist-heat cooking, 618 monosodium glutamate (MSG), 4–5 monounsaturated fatty acids (MUFA), 351 MOX agar, 77 Multi-locus Variable number of tandem repeat Analysis (MLVA), 65 multivariate data analysis, 169 MVA see multivariate data analysis myosin, 276, 596–7 N-nitroso amines (NAs), 488–94 analysis, 493–4 formation, 491 inhibition, 491–3 occurrence, 494 content in meat products, 494 physical and chemical properties, 488, 490–1 NaCl see sodium chloride nanotechnology, 443 natural antimicrobials advantages and new perspective for application, 316–20 bacteria used as commercial starter cultures, 317 starter cultures/additives, 318 bacteriocins for food preservation, 304–10 enterocins and meat manufacturing, 306–8 nisin, 304–5 novel bacteriocins and innovative alterations in meat processing, 308–10 other bacteriocins and their use in meat processing, 306 combined effect with other barriers, 313–15 food grade sanitisers, 315 plants extracts for achieving shelf-life stability in meat products, 310–13 natural plant extracts in different foods, 311 oregano essential oil, 311–13 processed meat products, 299–320 range for food application, 301–13 probiotics for food preservation, 302–4 Natural Choice Roast Beef, 452 natural smoke condensates, 528 neutral lipids, 347–8 new product development (NDP), 172 NFE-S, 468 nisin, 304–5, 388 nitrate, 69 nitrite, 598 non-governmental organisations (NGOs), 151 non-meat protein (NMP), 223

Notifiable Diseases Surveillance System (NDSS), 82 Novel Food and Novel Food Ingredients Regulations (258/97/EC), 392 novel foods, 392–3 nuclear magnetic resonance (NMR) spectroscopy, 547 nutraceuticals, 372–4 future trends, 392–3 novel food legislation, 392–3 microbial safety, 384–90 combination strategies, 388–90 microorganism-derived antimicrobials, 388 plant origin, 385–7 processed meats, 374–7 achieving healthier meat and meat products, 376–7 bioactive nutraceutical components, 375 implications of meat for human health, 375–6 product quality, 377–84 lipid oxidation, 378–81 product colour, 382–3 product texture, 381–2 recent published articles on published meat products, 379–80 volatile composition, 383–4 use and effects on processed meat products, 372–93 acceptability, 390–2 global functional food market commodity market share, 374 nutrition claims, 143 nutrition labelling, 153 nutritional content, 202, 203–4 enhancement in processed meat products, 421–43 absorption and retention in a marinating system, 427–9 background and terminology associated with marinating, 423–7 commercially available Indian and Chinese marinades and sauces, 422 established effects of marinating, 438–41 functional ingredients of marinating, 429–35 future research in marinating technology, 442–3 methods of marinade delivery, 435–8 sensory evaluation, 441–2 sample materials, 203–4 nylon 6, 684 nylon 6.6, 684 oat bran, 361–2 oat fibre, 361–2

© Woodhead Publishing Limited, 2011

Index OEO see oregano essential oil off-flavour, 116 off-odour, 116–17, 119, 121 ohmic heating, 648–50 Olestra, 347 online quality assessment, 546–63 automation and integration of quality measurements, 562–3 food safety, 558–62 advances in foreign object detection, 561–2 fluorescence, 561 food freshness, 562 HACCP plan for sausage making, 560 IR imaging, 558–60 temperature calculated with Mikron 7302, 559 X-rays, 560–1 meat composition and attributes, 547–52 functional foods, 551– 2 microwaves, 549 NIR fat maps for inhomogeneous trimmings, 550 NIR spectroscopy, 547–8 online interaction, 550–1 room temperature absorption spectra, 551 X-rays, 548–9 visual inspection of products, 552–8 correct insertion of Hennessy Grading Probe, 554 machine vision, 555–6 multispectral and hyperspectral imaging, 556–8 VIS spectroscopy, 553–5 Optical fibre probes, 555 oral appeal, 466–7 oregano, 312 oregano essential oil, 311–13 organic acids, 431–2 Origanum vulgare see oregano over-wrapping, 686–7 Oxford agar, 77 oxidation, 514–15 oxidation-reduction potential (ORP), 120 oxygen scavengers, 699 Oxysorb, 700 OzFoodNet, 73 packaging, 463 packaging-dependent deterioration, 671 packaging systems consumer trends in food packaging, 677–9 product convenience, 678–9 cooked meat and muscle-based, convenience-style processed foods, 666–701

717

choosing packaging materials for cooked meat products, 679–81 future trends, 701 cooked meat products, 669–72 effects of cooking meat and meat products, 669–70 types of deterioration, 670–2 cooked meat products by variety, 670 definition of packaging and its functions, 672–5 driving forces for packaging consumption, 672–4 interactions of packaging with the cooked food products and environment, 673 packaging requirements for musclebased cooked food products, 674–5 developments and recent advances, 686–701 advantages of retort pouches over cans or jars, 695 baked Irish ham vacuum packed in heat-shrinkable film, 687 boil and steam cooking packaging, 692–4 gas mixtures used in MAP, 691 modified atmosphere packaging, 689–92, 693 over-wrapping or stretch-wrapping, 686–7 packaging with enclosed free-oxygen scavenging agent, 699–701 processed meat products packaged under MAP, 693 ready meal packaging containing a SmartCode, 699 retort sterilised packaging, 694–7 selected examples of smart packaging technologies, 698 smart packaging, 697–9 vacuum packaging, 687–9 influence of key trends on consumer behaviour, 675–7 global cuisine ‘Heat n’ Serve’ range, 676 packaging materials and forms used, 681–6 fibre-based materials, 681–2 glass, 682 metal, 685–6 plastics, 682–5 PALCAM agar, 77 palm oil, 353 pan-frying, 619 partial-freezing, 583 partially frozen, 583 particle size reduction, 285–8 Pascal foods, 591

© Woodhead Publishing Limited, 2011

718

Index

paste marinades, 436 pasteurisation, 634, 638–9 pathogen control, 111–14 D-values of foodborne pathogens, 113 meat products shelf-lives after irradiation, 112 survival and growth of L. monocytogenes on irradiated vacuum-package food, 115 Pavitinand, 257 Pearl Meat Binders, 272, 277 Pearl Meat F, 284, 285 Pearl Meat MX-30, 284, 285 pectin, 257–8 pH, 516 phosphates, 275, 430–1, 598 phospholipids, 347–8 physical entrapment theory, 622 pink defect, 458 plasma, 219 and its derivatives, 226–9 plasma protein fractions, 227–9 poaching, 618 polyamide, 684–5 polycarbonates, 685 polycyclic aromatic hydrocarbons, 478–83 analysis, 482 behaviour in organisms, 480–1 characterisation, 479–80 legislative aspects and international normalisation in smoked meat, 481–2 occurrence, 482–3, 484 benzo(a)pyrene content in smoked, barbecued and grilled meat products, 484 principles of smoking, 479 Polydextrose, 347 polyethylene, 683 polyethylene terephthalate, 685 polyphosphates, 430, 600 polypropylene, 683 polystyrene, 684 polyunsaturated fatty acids, 351 polyvinyl chloride, 683–4 polyvinylidene chloride, 684 potassium benzoate, 114 potassium caseinates, 251–2 potassium chloride, 340 potassium lactate, 114 potentiometric titration, 530 poultry meat marketing standards, 147 POWRSMOKER, 536 cleaning procedure, 537–8 troubleshooting guide, 539–40 Prairie Grove, 452 prebiotics, 408–9 and probiotics in meat products, 403–13

concept of probiotics, prebiotics and synbiotics, 411 future trends, 411–13 meat products, 410–11 meat protein-derived prebiotic peptides, 409–10 representative ingredients, 408–9 pressure pre-cooked meat products, 602–3 pressure shift freezing, 585 principal component analysis (PCA), 165 Pro-tect, 561 Probelia, 78 probiotics, 302–4, 404–5 meat fermentation, 405–8 fermented meat spread product, 406 prebiotics in meat products, 403–13 commercially available probiotic bacterial strains and their products, 405 concept of probiotics, prebiotics and synbiotics, 411 dairy products utilizing Lactobacillus rhamnosus GG strain, 406 future trends, 411–13 meat fermentation, 405–8 process filing, 628 processed meat advances in high pressure technology application, 590–609 effect on meat and meat products quality, 592–6 future trends, 606–9 microbial control in meat and products, 603–5 new applications in meat industry, 605 pressure-processed meat products, 596–603 blood by-products as ingredients, 218–33 applications, 223–32 blood characterisation, recovery and processing, 218–23 future trends, 232–3 cooked meats and muscle-based, convenience-style processed foods packaging, 666–701 choosing packaging materials for cooked meat products, 679–81 consumer trends in food packaging, 677–9 cooked meat products, 669–72 definition of packaging and its functions, 672–5 developments and recent advances, 686–701 future trends, 701 influence of key trends on consumer behaviour, 675–7

© Woodhead Publishing Limited, 2011

Index packaging materials and forms used, 681–6 globalisation and challenges of food safety, 54–70 nutrition, 68–9 trade liberalisation, 55–68 heat and processing generated contaminants, 478–500 biogenic amines, 483–8 heterocyclic amines, 495–9 N-nitroso amines, 488–94 polycyclic aromatic hydrocarbons, 478–83 hydrocolloids utilisation, 243–64 application, 249–62 challenges faced by the meat industry today, 247–8 future trends, 262–4 meat matrix, 245–6 regulation and scrutiny concerning usage in processed meats, 248–9 impact of refrigeration on safety and quality, 567–86 advances in technology and practice, 582–5 current understanding, 570–82 future trends, 585–6 listeriosis, salmonellosis and verocytotoxigenic E. coli contamination, 72–93 Escherichia coli, 78–85 Listeria monocytogenes, 73–8 Salmonella, 85–92 novel and natural antimicrobials for safety and shelf-life stability, 299–320 advantages and new perspective for application, 316–20 combined effect with other barriers, 313–15 food grade sanitisers, 315 range for food application, 301–13 nutraceutical effects on product quality, safety and acceptability, 372–93 acceptability, 390–2 functional food market, 374 future trends, 392–3 microbial safety, 384–90 processed meats, 374–7 product quality, 377–84 online quality assessment, 546–63 automation and integration of quality measurements, 562–3 food safety, 558–62 meat composition and attributes, 547–52 visual inspection of products, 552–8 reducing salt, 331–40

719

influences of salt on processed meats, 332–5 processed meats development with low salt content, 335–40 regulation of labels in the European Union, 134–154 Codex Alimentarius, 151–2 food information provision to consumers, 152–3 food law regulation, 136–7 information source and advice, 153–4 labelling and claim rules, 137–46 other measures, 147–51 thermal processing technologies on sensory quality, 617–55 consumer preference, 651–3 future trends, 653–5 meat quality, 620–3 thermal processing, 623–8 thermal processing methods, 628–51 see also consumer-led processed meat products processed meat products consumer trends and emerging markets, 30–49 chicken-based tapas in high pressure technology, 32 consumer judgement on meat quality, 31–3 consumer trends, 34–7 emerging markets, 45–7 future trends, 47–9 information sources and advice, 49 positioning strategies, meat industry, 37–45 processed meat sales, 47 products with meat ingredients, 48 irradiation usage, 109–123 future trends, 123 irradiation effects on meat quality, 114–21 pathogen control, 111–14 quality changes prevention, 121–3 marinating and enhancement of nutritional content, 421–43 absorption and retention in a marinating system, 427–9 background and terminology associated with marinating, 423–7 commercially available Indian and Chinese marinades and sauces, 422 established effects of marinating, 438–41 functional ingredients of marinating, 429–35 future research in marinating technology, 442–3

© Woodhead Publishing Limited, 2011

720

Index

methods of marinade delivery, 435–8 sensory evaluation, 441–2 reducing fats, 346–66 alternative fat-replacing ingredients, 355–65 consequences, 349–50 future trends, 365–6 importance, 346–7 role of fat, 347–9 saturated fat replacement, 351–5 technological methods, 350–1 sensory science in product development, 156–77 future trends, 166–71 methodologies and approaches, 162–6 status of sensory-based quality control, 157–62 product-dependent deterioration, 671 product development capacity, 169 product quality, 377–84 Proliant Inc., 468 Prosciutto Toscano PDO, 43 Protected Denomination of Origin (PDO), 43 Protected Designation of Origin (PDO), 145 protected food names, 145–6 Protected Geographical Indication (PGI), 145 protein solubility, 334–5 proteins, 250–1, 251–3 animal origin, 251–3 blood protein, 253 caseinates, 251–2 gelatin, 252–3 whey protein, 251 plant origin, 250–1 soy protein, 250 wheat gluten, 250–1 proteolysis, 510–13 dry-cured ham, 510–11 water activity in external muscle, 511 water activity levels on muscle cathepsins and calpain, 512 dry-fermented sausages, 511–13 major steps, 510 Pseudomonas, 222 pulse electric field, 44, 314 pulsed field gel electrophoresis (PFGE), 65 PulseNet, 65 pyridoimidazole, 497 pyridoindole, 497 QMonitor, 550, 558 Qualified Presumption of Safety (QPS), 301 quality control restructured meat products, 291–5 appearance, 292

flavour, 293–4 texture, 292–3 quality cues, 31 quality improvement restructured and convenience meat products, 450–72 future trends, 470–2 product quality improvement, 463–70 quality issues, 453–63 whole tissue and convenience meat products, 451–3 quantitative descriptive analysis (QDA) methods, 164 quantitative ingredient declaration (QUID), 138 quantum satis principle, 254 Quick Dry Slice, 319 R-value, 629 Radarange, 646 radiation, 568, 624 radiation-based systems, 642–50 infrared cooking, 642–3 general frequency bands and wavelengths, 643 microwave and RF, 643–8 continuous microwave system outline, 647 critical process factors in microwave heating, 648 frequencies assigned by FCC for industrial, scientific and medical use, 644 ohmic heating, 648–50 radio frequency identification (RFID), 45, 62 radio frequency identification (RFID) enabled packaging, 697 radio frequency (RF), 643–8 Raman spectroscopy, 552 Rapid Alert System for Feed and Food, 57 rapid chilling, 583 Rapid’L.mono agar, 78 RASFF see Rapid Alert System for Feed and Food raw ham-like meat product, 602 ready-to-eat (RTE), 111 recommended daily allowance (RDA), 57 red blood cells (RBC), 219 and its derivatives, 223–6 globin, 224–5 globin hydrolysates, 225 Hb as natural red colourant, 225–6 Red Green Blue colour spaces, 553 refrigeration advances in technology and practice, 582–5

© Woodhead Publishing Limited, 2011

Index crust freezing, 583–4 high pressure freezing, 585 magnetic resonance freezing, 585 superchilling, 583 tempering, 584 impact on processed meat quality, 576–82 chilled storage and display, 577–80 chilling, 576–7 freezing, 580–1 frozen storage and display, 581–2 processing times and weight losses from meat, 578 storage life for vacuum packed sliced cured meat products, 579 weight loss from unwrapped hams in frozen storage, 581 impact on processed meat safety, 571–6 chilled storage and display, 576 chilling, 571–6 cooling regimes and cooling time for uncured and cured cooked meat, 574–5 freezing, 576 international chilling time guidelines/ recommendations for cooling of cooked foods, 572 impact on processed meat safety and quality, 567–86 current understanding, 570–82 future trends, 585–6 lowest operating temperatures, 570 spray/evaporative cooling of saveloy sausages, 568 surface heat transfer coefficients, 570 regional preferences and consumer demands, meat, 3–29 choice effect, meat consumption, 5 consumer determinants, 5–16 future trends, meat consumption, 26–9 meat consumption patterns and economic data, 16–26 taste effect, meat consumption, 4–5 Regulation 178/2002, 136, 152 Regulation 315/93, 148 Regulation 509/2006, 145 Regulation 510/2006, 145 Regulation 700/2007, 141 Regulation 834/2007, 145 Regulation 853/2004, 146 Regulation 1760/2000, 140 Regulation 1829/2003, 148 Regulation 1830/2003, 148 Regulation 1881/2006, 151 Regulation 2008/543, 147 Regulation 2008/1333, 147–8, 151 Regulation (EC) No. 178/2002, 65 Regulation (EC) No. 852/2004, 64

721

Regulation (EC) No. 1332/2008, 61 Regulation (EC) No. 1774/2002, 220 Regulation (EC) No. 1925/2006, 57 Regulation (EC) No. 2073/2005, 63 restructured meat, 271 product quality control, 291–5 products quality control appearance, 292 flavour, 293–4 texture, 292–3 restructured meat products aesthetics-related quality problems, 455–7 wrong fibre alignment during restructuring, 457 improving quality, 450–72 convenience, 469–70 examples, 453 flavour and aroma appeal, 467–9 future trends, 470–2 improving oral appeal, 466–7 visual appeal, 463–6 whole-tissue meats, 451 quality issues, 453–7, 460–3 aesthetics-related quality problems, 455–7 flavour and odour-related, 461–2 loss of convenience, 462–3 National Meats NZ Limited Quality Assurance Product Specifications for cooked restructured boneless lamb roll, 456 texture/tenderness-related, 460–1 restructured whole-tissue meat, 451 restructuring, 451 retort sterilised packaging, 694–7 advantages of retort pouches over cans or jars, 695 retorting, 620 Roasted Beef Flavorin, 468 Roastin, 468 roasting, 619 robotics, 562–3 Robust Elite, 468 rub see dry marinades Ruggedized Advance Pathogen Identification Device (RAPID), 78, 85 Salmonella, 85–92 antibiotic resistant, 90–1 contamination routes and control regulations, 86–7 detection methods, 91–2 incidence, processed meats, 87–90 outbreaks due to beef products, 89 outbreaks due to pork products, 88

© Woodhead Publishing Limited, 2011

722

Index

Salmonella Typhimurium phage type DT104, 90–1 salt, 274–5, 430 development of processed meats with low salt content, 335–40 sodium reduction in food products, 336–7 use of masking agents, 340 influences on processed meats, 332–5 microbial stability, 332–3 protein solubility and texture, 334–5 water-holding capacity, 333–4 reduction in processed meat products, 331–40 salt replacers effect, 339–40 aroma volatile compounds perception, 339–40 muscle enzyme activity, 339 salt replacers, 339–40 saturated fat, 351–5 sautéing, 619 savoriness see umami SBF see science-based formulation science-based formulation, 186–90 history in meat industry, 187–90 reverse-engineering formulae using LCF and SBF, 214 Scientific Committee on Veterinary Measures relating to Public Health (SCVMPH), 80 scientific modelling advanced application issues, 212–14 cost of least-cost formulation, 213–14 inventories, 213 multicomponent formulation, 213 multiproduct formulation, 213 reverse-engineering formulae using LCF and SBF, 214 blended meat products, 185–215 requirement-oriented formulation, 185–6 least-cost formulation model, 186–96 availabilities, 195–6 central assumptions, 190–2 history in meat industry, 187–90 prices, 195 product formula input–output model, 193–5 linear science-based models for meat products properties, 196–207 compositional groupings (logical relationships), 199 crude chemistry (proximate analysis), 199, 200–1 flavour attributes, 205 functional attributes, 202, 205, 206–7 mixture models, 197–9

nutritional content, 202, 203–4 physical attributes, 205 PWBFRANK product formulation material usage report, 211 product formulation requirements specification and report, 209 sample nutritional label report, 212 solving the LCF-SBF problem, 208–12 problem build, 208–10 problem solution, 210 problem un-build, 210, 211–12 sensitivity analysis, 210, 212 searing, 619 seasonings, 275 seaweeds, 382 Secretariat of the International Plant Protection Convention (IPPC), 56 sensory evaluation, 441–2 sensory profiling methods, 157 sensory quality acceleration of processes and improvement in cured meat products, 517–19 accelerated processing of cured and fermented meat products, 518 dry-cured ham, 517–19 dry-fermented sausages, 519 biochemical basis of flavour development, 509–15 glycolysis in fermented meat, 513–14 lipolysis, 513, 514 oxidation, 514–15 proteolysis, 510–13 improvement in cured and fermented meat products, 508–19 basis for colour and texture development, 515–16 processing factors affecting sensory quality, 516–17 trends to accelerate the processes and/ or improve the sensory quality, 517–19 sensory quality system (SQS), 167 sensory science case studies, 173–5 ConSense strategy overall dynamics, 171 preference mapping, 170 stages of development, 168 consumer-led processed meat products development, 156–77 sensory profiling methods, 176 successful consumer processed meat products, 172–3 future trends: holistic implementation, 166–71

© Woodhead Publishing Limited, 2011

Index sensory-based methodologies and approaches descriptive analysis, 164–5 flash profiling, 166 QC methodologies, 162–4 scoring sheets, 163 sensory-based quality control past and present status, 157–62 history, 157–8 sensory analysis, consumer and processed meats, 158–9 sensory-instrumental methods, 161–2 sensory QC programmes, 160–1 successful consumer processed meat products development, 172–3 shelf-life stability natural and novel antimicrobials in processed meat products, 299–320 advantages and new perspective for application, 316–20 combined effect with other barriers, 313–15 food grade sanitisers, 315 range for food application, 301–13 Shiga toxin enzyme immunoassay (StxEIA), 85 Shiga-toxin producing E. coli (STEC), 78–9 shrink loss, 193 simmering, 618 Simple Steps, 470 smart oven, 698 smart packaging, 697–9 ready meal packaging containing a SmartCode, 699 selected examples of smart packaging technologies, 698 SmartCode, 698, 699 smoked meat products assorted processed meat products using natural liquid smoke condensates, 528 future trends, 544–5 liquid smoke condensates application to muscle-based food products, 533–44 atomisation, 533–6 calibration of deluxe panel, 536 drenching, 538–43 internal addition, 543 liquid smoke shower produced from a drench pan, 541 maintenance of atomisation units, 536–8 smoked nets, 544 spraying systems, 544 vaporous cloud produced by atomisation nozzle, 536 natural smoke condensates vs traditional smoking technologies, 528–33

723

critical smoke components of liquid smoke condensate, 530–1 liquid smoke condensate production, 531–3 natural liquid smoke condensate manufacturing process, 532 process of smoking muscle food products, 527 sensory and nutritional quality improvement, 527–45 smoked nets, 544 smoking, 479 soaking see immersion sodium caseinate, 251 sodium chloride, 331, 598 sodium diacetate, 114 sodium tripolyphosphates, 430 Solid Lay-Down process, 700 sous vide cooking, 639 sous vide processing, 688–9 soy protein, 250, 381–2, 433 Spectrum methods, 164 spice extracts, 434–5 spice rub see dry marinades spices, 385, 387, 434–5 spraying systems, 544 SPS Agreement see Agreement on Application of Sanitary and Phytosanitary Measures Staphylococcus aureus, 604 Star-San, 315 starch, 253–4, 357–8 steam cooking packaging, 692–4 steaming, 618 stewing, 618–19 still marinating see immersion stir-frying, 619 stretch-wrapping, 686–7 Stubbs and More calculation, 142 Stumbo equation, 625 styrene butadiene copolymer (SBC), 684 sub-cooled, 583 sugars, 261–2 super-chilled, 583 super-cooled, 583 superchilling, 583 surveillance systems, 64–6 incidence and origin of rapid alert, 67 Swiss Association for Nutrition, 34 synbiotics, 411 TaqMan, 78, 92 TBT Agreement see Agreement on Technical Barriers to Trade techno-functional ingredients, 223 tempering, 584 tempura batters, 640

© Woodhead Publishing Limited, 2011

724

Index

tenderness, 439–40 terahertz gap, 561 terahertz radiation, 561–2 TGase see transglutaminase thermal processing technologies effects on sensory quality of meat and meat products, 617–55 consumer preference, 651–3 future trends, 653–5 equivalent time–temperature combinations to achieve 6-D reduction L. monocytogenes, 626 psychrotrophic Cl. botulinum type b, 627 meat quality, 620–3 meat batter or exudates principal components and functional properties of salt soluble proteins, 622 methods, 628–51 conduction-based systems, 629–30 convection-based systems, 630–42 hybrid/novel cooking systems, 650–1 radiation-based systems, 642–50 thermal processing, 623–8 fundamentals of cooking, 623 predictive modelling, 625–8 thermodynamics, 624–5 thermal resistance, 629 thermal shock, 624–5 ThermoSecure, 556 thiobarbituric acid, 594 traceability, 61–2 trade liberalisation, 55–68 European import rules, 56–7 logistics and transport, 62–3 microbial load as quality cues, 63–4 processed meat labelling and traceability, 57–62 beef labelling, 59, 60 Commission Directive 2001/101/EC, 58–9 Council Directive 94/65/EC, 59 Council Directive 2000/13/EC, 58 draft regulation, consumers information (COM (2008) 40), 59–61 restructured labelling, meat products, 61 traceability – EC regulation 178/2002, 61–2 procurement policies, 66–8 surveillance systems, 64–6 incidence and origin of rapid alert, 67 Traditional Specialities Guaranteed (TSG), 145

transglutaminase, 260–1, 282–4, 600 chemical structure, 261 tumbling, 437–8 Tyson’s Fully Cooked Heat ‘N Eat Dinner Meats, 452 ultra-chilled, 583 umami, 4–5, 653 UNIVAC computer, 188 Univac Corporation, 188 vacuum packaging, 122, 687–9 baked Irish ham vacuum packed in heatshrinkable film, 687 vegetarian diet, 36–7 VerifEYE Solo, 561 verocytotoxigenic E. coli (VTEC), 78–85 Veterinary Laboratories Agency, 65 Vidas, 78 VIS spectroscopy, 553–5 visual appeal, 463–6 visual inspection, 552–8 correct insertion of Hennessy Grading Probe, 554 machine vision, 555–6 multispectral and hyperspectral imaging, 556–8 VIT-listeria, 78 Vitamin E, 122 warmed over flavour, 160, 276, 438, 461–2 WarnexTM Real-Time PCR Rapid Pathogen Detection System, 85 water, 431 water activity, 333 water holding capacity, 120, 190, 205, 259, 333–4, 427, 547, 592 water immersion systems, 638–9 wellness, 35–7 wheat gluten, 250–1 whey protein, 251 Wise Food Processing, 315 Wix-Fresh, 468 WOF see warmed over flavour Wolfking Continuous Fat Analyser, 548 wood smoke, 527 Working Group on Diet and Cancer of the Committee on Medical Aspects of Food and Nutrition Policy, 68–9 World Health Organisation, 42, 151, 301 consensus conference, 68–9 World Trade Organisation, 55 xanthan, 259 XYZ tristimulus colour spaces, 553

© Woodhead Publishing Limited, 2011