Hydrocolloids in Food Processing

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Hydrocolloids in Food Processing

Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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The IFT Press series reflects the mission of the Institute of Food Technologists – to advance the science of food contributing to healthier people everywhere. Developed in partnership with Wiley-Blackwell, IFT Press books serve as leading-edge handbooks for industrial application and reference and as essential texts for academic programs. Crafted through rigorous peer review and meticulous research, IFT Press publications represent the latest, most significant resources available to food

scientists and related agriculture professionals worldwide. Founded in 1939, the Institute of Food Technologists is a nonprofit scientific society with 22,000 individual members working in food science, food technology, and related professions in industry, academia, and government. IFT serves as a conduit for multidisciplinary science thought leadership, championing the use of sound science across the food value chain through knowledge sharing, education, and advocacy.

IFT Book Communications Committee Dennis R. Heldman Joseph H. Hotchkiss Ruth M. Patrick Terri D. Boylston Marianne H. Gillette William C. Haines Mark Barrett Jasmine Kuan Karen Nachay

IFT Press Editorial Advisory Board Malcolm C. Bourne Dietrich Knorr Theodore P. Labuza Thomas J. Montville S. Suzanne Nielsen Martin R. Okos Michael W. Pariza Barbara J. Petersen David S. Reid Sam Saguy Herbert Stone Kenneth R. Swartzel

A John Wiley & Sons, Ltd., Publication

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Editor

Thomas R. Laaman

A John Wiley & Sons, Ltd., Publication

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Edition first published 2011
C 2011 Blackwell Publishing, Ltd. and Institute of Food Technologists Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing program has been merged with Wiley’s global Scientific, Technical, and Medical business to form Wiley-Blackwell. Editorial Office 2121 State Avenue, Ames, Iowa 50014-8300, USA For details of our global editorial offices, for customer services, and for information about how to apply for permission to reuse the copyright material in this book, please see our Website at www.wiley.com/wiley-blackwell. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by Blackwell Publishing, provided that the base fee is paid directly to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923. For those organizations that have been granted a photocopy license by CCC, a separate system of payments has been arranged. The fee code for users of the Transactional Reporting Service is ISBN-13: 978-0-8138-2076-7/2011. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Library of Congress Cataloging-in-Publication Data Hydrocolloids in food processing / edited by Thomas R. Laaman. p. cm. – (IFT Press series) Includes bibliographical references and index. ISBN 978-0-8138-2076-7 (hardback : alk. paper) 1. Hydrocolloids. I. Laaman, Thomas. TP456.H93H93 2010 664–dc22 2010011387 A catalog record for this book is available from the U.S. Library of Congress. Set in 11.5/13.5 Times NR PS by Aptara
R Inc., New Delhi, India Printed in Singapore Disclaimer The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation warranties of fitness for a particular purpose. No warranty may be created or extended by sales or promotional materials. The advice and strategies contained herein may not be suitable for every situation. This work is sold with the understanding that the publisher is not engaged in rendering legal, accounting, or other professional services. If professional assistance is required, the services of a competent professional person should be sought. Neither the publisher nor the author shall be liable for damages arising herefrom. The fact that an organization or Website is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Website may provide or recommendations it may make. Further, readers should be aware that Internet Websites listed in this work may have changed or disappeared between when this work was written and when it is read. 1

2011

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Titles in the IFT Press series r Accelerating New Food Product Design and Development (Jacqueline H. Beckley, Elizabeth J. Topp, M. Michele Foley, J.C. Huang and Witoon Prinyawiwatkul)

r Advances in Dairy Ingredients (Geoffrey W. Smithers and Mary Ann Augustin) r Bioactive Proteins and Peptides as Functional Foods and Nutraceuticals (Yoshinori Mine, Eunice r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r

Li-Chan and Bo Jiang) Biofilms in the Food Environment (Hans P. Blaschek, Hua H. Wang, and Meredith E. Agle) Calorimetry and Food Process Design (G¨on¨ul Kaletunc¸) Food Ingredients for the Global Market (Yao-Wen Huang and Claire L. Kruger) Food Irradiation Research and Technology (Christopher H. Sommers and Xuetong Fan) Foodborne Pathogens in the Food Processing Environment: Sources, Detection and Control (Sadhana Ravishankar, Vijay K. Juneja and Divya Jaroni) High Pressure Processing of Foods (Christopher J. Doona and Florence E. Feeherry) Improving Import Food Safety (Wayne C. Ellefson, Lorna Zach and Darryl Sullivan) Microbial Safety of Fresh Produce: Challenges, Perspectives and Strategies (Xuetong Fan, Brendan A. Niemira, Christopher J. Doona, Florence E. Feeherry and Robert B. Gravani) Microbiology and Technology of Fermented Foods (Robert W. Hutkins) Multiphysics Simulation of Emerging Food Processing Technologies (Kai Knoerzer, Pablo Juliano, Peter Roupas and Cornelis Versteeg) Multivariate and Probabilistic Analyses of Sensory Science Problems (Jean-Franc¸ois Meullenet, Rui Xiong, and Christopher J. Findlay Nanoscience and Nanotechnology in Food Systems (Hongda Chen) Natural Food Flavors and Colorants (Mathew Attokaran) Nondestructive Testing of Food Quality (Joseph Irudayaraj and Christoph Reh) Nondigestible Carbohydrates and Digestive Health (Teresa M. Paeschke and William R. Aimutis) Nonthermal Processing Technologies for Food (Howard Q. Zhang, Gustavo V. Barbosa-C`anovas, V.M. Balasubramaniam, Editors; C. Patrick Dunne, Daniel F. Farkas, James T.C. Yuan, Associate Editors) Nutraceuticals, Glycemic Health and Type 2 Diabetes (Vijai K. Pasupuleti and James W. Anderson) Organic Meat Production and Processing (Steven C. Ricke, Michael G. Johnson and Corliss A. O’Bryan) Packaging for Nonthermal Processing of Food (J. H. Han) Preharvest and Postharvest Food Safety: Contemporary Issues and Future Directions (Ross C. Beier, Suresh D. Pillai, and Timothy D. Phillips, Editors; Richard L. Ziprin, Associate Editor) Processing and Nutrition of Fats and Oils (Ernesto M. Hernandez, and Afaf Kamal-Eldin) Processing Organic Foods for the Global Market (Gwendolyn V. Wyard, Anne Plotto, Jessica Walden and Kathryn Schuett) Regulation of Functional Foods and Nutraceuticals: A Global Perspective (Clare M. Hasler) Resistant Starch: Sources, Applications and Health Benefits (Yong-Cheng Shi and Clodualdo Maningat) Sensory and Consumer Research in Food Product Design and Development (Howard R. Moskowitz, Jacqueline H. Beckley, and Anna V.A. Resurreccion) Sustainability in the Food Industry (Cheryl J. Baldwin) Thermal Processing of Foods: Control and Automation (K. P. Sandeep) Trait-Modified Oils in Foods (Frank T. Orthoefer and Gary R. List) Water Activity in Foods: Fundamentals and Applications (Gustavo V. Barbosa-C`anovas, Anthony J. Fontana Jr., Shelly J. Schmidt, and Theodore P. Labuza) Whey Processing, Functionality and Health Benefits (Charles I. Onwulata and Peter J. Huth)

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Table of Contents

Preface Contributor List

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Chapter 1

Hydrocolloids: Fifteen Practical Tips Thomas R. Laaman

Chapter 2

Hydrocolloids in Salad Dressings Alan H. King

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Chapter 3

Hydrocolloids in Muscle Foods James W. Lamkey

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Chapter 4

Hydrocolloids in Bakery Products William Santa Cruz

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Chapter 5

Hydrocolloids in Bakery Fillings Marceliano B. Nieto and Maureen Akins

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Chapter 6

Hydrocolloids in Frozen Dairy Desserts Philip A. Rakes and Thomas R. Laaman

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Chapter 7

Hydrocolloids in Cultured Dairy Products Joseph Klemaszewski

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Chapter 8

Hydrocolloids in Restructured Foods Ian Challen and Ralph Moorhouse

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Chapter 9

Hydrocolloids in Flavor Stabilization Milda E. Embuscado

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Chapter 10 Hydrocolloid Purchasing I: History and Product Grades Thomas R. Laaman

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Chapter 11 Hydrocolloid Purchasing II: Pricing and Supplier Evaluation Thomas R. Laaman

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Index

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This is a highly practical book written primarily for three groups who make their living in the food industry: product development scientists, quality assurance scientists, and purchasing directors and managers. University professors who want to impart industry-based practical knowledge to their students and food science students, especially those in product development courses can also richly benefit from this work. For students, the chapters of this book can provide valuable insights into the results of decades long practical research in developing food products utilizing hydrocolloids as key components. Although most of the writers of this book have Ph.D. degrees, and nearly all of the rest have M.S. degrees, these writers also have decades of lab, pilot plant, and plant experience in this field. They have combined a thorough scientific education with the practical hands on experience required to master this difficult area of practical hydrocolloid applications. These writers were all chosen because they are the practical masters in hydrocolloid knowledge in their specific food areas. How should this book be read? Carefully, thoughtfully, and repetitively. Practical hydrocolloid applications can be mastered and once mastered, provide one of the most valuable job skills in this business. So many foods depend on thorough mastery of the hydrocolloid component and once that is accomplished, the rest of the food product usually just falls together, literally. Of course there are other specialized knowledge areas that are important to many foods, such as flavor chemistry, but hydrocolloids even impact flavor quite noticeably. In any case, mastery in this field usually requires many reviews of the same information, until it becomes second nature. ix

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Thus, it is recommended that this book be kept in the lab or office, and read over and over again until it becomes thoroughly familiar. Also, regardless of the food area that one is employed in, reading all the chapters in the book will pay good dividends. Each chapter provides valuable insights into various hydrocolloids and these insights extend well beyond the specific food applications being discussed. Also, much of the innovativeness in our food industry results from applying concepts used in one branch of the food industry to another branch of industry. Finally, it is good to become familiar with other branches of the food industry because one may be employed there in the future; few jobs are all that stable in this industry. Some authors of chapters in this book have referenced many other sources, some only a few or none. Why is that? The truth of the matter is much of the key practical knowledge in the hydrocolloid area is proprietary. Those authors who are employed by various hydrocolloid suppliers have the approval of their individual company to publish the material in their chapters that may belong to that company. But even in those cases some or much of the material in their chapters may be knowledge they may have picked up in various research assignments they have had over the course of their careers, in many companies, or as consultants. It would be difficult in most cases to reference manuals published by companies in the hydrocolloid field since the material is so totally hackneyed. Six different companies that sell a certain hydrocolloid have almost the identical information in their brochures and that same material was already found in publications from 30 years ago of companies that no longer exist. In any case, much material in this book is new and has never appeared in print before in any company brochure. There can be several hydrocolloid combinations that will make quality, stable food products. Most of the chapter authors try to provide some of these alternate approaches. In cases where one combination is suggested there may be other combinations that will also work. In those cases gaining expertise in how and why one hydrocolloid combination is particularly effective can stimulate the reader to consider other approaches as well. That is all part of hydrocolloid learning and mastery. I would expect that some of the more creative readers of this book will find new approaches to their specific product development challenges based on the foundations laid in this volume.

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This book is divided into three sections. The first chapter provides important general practical concepts in the use of hydrocolloids that are applicable to many food products. Chapters 2–9 provide food-by-food specific details in the utilization of hydrocolloids in these various categories. In most cases, the chapters explain not only how to successfully use hydrocolloids but most of the keys toward making those food categories themselves. Thus, the chapters are actually practical guides to making specific foods. Chapters 10 and 11 provide a thorough guide to purchasing hydrocolloids, and contain valuable information for purchasing directors, QA scientists, and product development specialists. It is hoped that this book not only helps significantly in practical ways in your current and future jobs, but that you begin to glimpse the love and fascination the complex world of hydrocolloids brings to us who have labored for so long in this viscous realm. Thomas R. Laaman Guaranteed Gums

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Contributor List

Maureen Akins (Chapter 5) TIC Gums Inc. White Marsh, MD, USA Ian Challen (Chapter 8) Hydrocolloid Solutions Houston, TX, USA William Santa Cruz (Chapter 4) Gums Per Tucson, AZ, USA Milda E. Embuscado (Chapter 9) McCormick & Co. Inc. Hunt Valley, MD, USA Alan H. King (Chapter 2) Rutgers, The State University of New Jersey Westfield, NJ, USA Joseph Klemaszewski (Chapter 7) Cargill Inc. Atlanta, GA, USA

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Thomas R. Laaman (Chapters 1, 6, 10, 11) Guaranteed Gums Madbury, NH, USA James W. Lamkey (Chapter 3) Symrise Teterboro, NJ, USA Ralph Moorhouse (Chapter 8) Hydrocolloid Solutions Houston, TX, USA Marceliano B. Nieto (Chapter 5) TIC Gums Inc. Abingdon, MD, USA Philip A. Rakes (Chapter 6) Main Street Ingredients La Crosse, WI, USA

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Chapter 1 Hydrocolloids: Fifteen Practical Tips Thomas R. Laaman

Tip One: Dissolving Hydrocolloids—The Influence of Mesh Size Achieving maximum hydrocolloid functionality in most food products begins with fully dissolving the hydrocolloid. Particle size or mesh size is a fundamental issue influencing solubility. The basic principle is that larger particles, corresponding to a coarser mesh size, such as 40–80 mesh, take longer to dissolve because the water takes longer to penetrate the dry hydrocolloid particle. A finer mesh particle, such as those that pass through 120, 150, or 200 mesh screens, takes less time for water to penetrate and become fully soluble. However, the converse of this situation is that a coarser size particle is less subject to lumping, while a finer mesh particle lumps more easily. Once lumps are formed, achieving full solubility becomes more difficult and also takes much more mixing to do so. There are two ways to overcome the potential for lumping for small particle size hydrocolloids. One is to use high agitation mixing. The other is to preblend the hydrocolloid with another dry ingredient such as sugar. By preblending, the hydrocolloid particles are separated from each other before entering the liquid, thereby minimizing lumping. In summary, if high agitation is used in dispersing the hydrocolloid or if it can be preblended with a dry ingredient then fine mesh grades will allow the most rapid solubility. If mixing is not as vigorous and Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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the hydrocolloid is not preblended then it is safer to use a coarser mesh product to avoid lumping, even though this will require more mixing time to achieve full solubility. Tip Two: Dissolving Hydrocolloids—The Influence of Temperature Some hydrocolloids require heat to dissolve. In these cases, it is important to know exactly how much temperature is required for the exact grade being used. There can be a substantial difference in the required temperature based on other ingredients, especially ions. Thus, it is important to heat the food product to different temperatures and determine the minimum temperature to achieve full functionality, in terms of maximum viscosity, gel strength, or stability of the food product. Temperature should be measured carefully. First, the thermometer or thermal probe being used must be precise and accurate. Mechanical thermometers are especially notorious for requiring frequent calibration to ensure accuracy. Another issue can be that the product mixing is not sufficiently vigorous during heating, allowing pockets of higher or lower temperature. This must be ascertained by moving the thermometer or thermal probe around to different locations in the mix to determine if temperature gradients exist. The minimum temperature achieved in any part of the mix should be the benchmark used to determine if the temperature is adequate. One contrary thought is important to add. Although it is important to achieve full functionality of a hydrocolloid, it is also true that some hydrocolloids can be partially degraded by excessive heat, for example, guar gum. Some other hydrocolloids may be degraded if there is a combination of heat and acid, for example, carrageenan. Therefore, the heating should be adequate to fully dissolve all the hydrocolloids and thus gain full viscosity, but not high enough that the viscosity is decreased due to partial hydrolysis of the hydrocolloid. Tip Three: Dissolving Hydrocolloids—The Influence of Cations Some hydrocolloids are not highly influenced by ions (except at very high ion concentrations), for example, agar, xanthan gum, guar gum, and locust bean gum. Several others are influenced in their solubilization by

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ions. These include sodium alginate, carrageenan, pectin, gellan gum, and sodium carboxymethyl cellulose (CMC). In these cases divalent cations and in some cases monovalent cations can influence the ability of the hydrocolloid to dissolve. Calcium is the major issue for sodium alginate, ␫-carrageenan, lowmethoxy pectin, and gellan gum. Potassium is the major issue for ␬-carrageenan, and sodium chloride can inhibit full viscosity development for CMC for certain grades. Options to circumvent reduced solubility include the following procedures. First, the ions can be added to the food product after the hydrocolloid has been dissolved. Second, for gums such as carrageenan, where the ions are present with the gum powder, solubility can be achieved by heating to a higher temperature. Third, for calcium, sequestrants can be added to bind these ions, at least temporarily, to allow the gum to dissolve. If water used in the processing plants is naturally quite high in calcium, this approach may be necessary if the water is not pretreated to remove these ions. Sequestrants include phosphate compounds such as sodium hexametaphosphate, tetrasodium pyrophosphate, and dipotassium phosphate and also citrates. Fourth, also for calcium, it is possible to add in very low solubility forms, thus largely delaying the calcium going into solution until after the gum has dissolved. Tricalcium phosphate is a very slow-dissolving calcium source, and dicalcium phosphate is also quite slow, the anhydrous form being slower than the dihydrate form.

Tip Four: Gelling Hydrocolloids—The Effect of Temperature Some hydrocolloids gel by simply cooling a hot solution. Agar and gelatin are the prime examples. Others gel after cooling, but also require ions to be present. These include ␬- and ␫-carrageenan, low-methoxy pectin, and gellan gum. High-methoxy pectin gels after cooling in a lowpH or high-sugar environment. Methyl cellulose forms and maintains a gel only while it is being heated. The first significant aspect is to make sure the gum has been given enough heat to fully dissolve, as discussed in Tip two. Whatever amount of gum is left undissolved will not contribute to the final gel properties. Only fully dissolved gum will gel when cooled. The exact gelling

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temperature will vary by the product and grade in a similar fashion as the solubility temperature varies. But this is generally less significant since eventually the product will generally be cooled to at least room temperature and fully gel. The key item to remember when gel formation is occurring during cooling is whether the gel will be broken apart during gel formation or left intact. ␫-Carrageenan has some gel “healing” properties, but most gums will not reform a gel well when the gel is broken up by agitation or motion during gelling. For most products, it is imperative that the gelled product is placed into a quiescent situation when the critical gelling temperature is near to being reached. For products where a disrupted gel is sought, it is still important to make sure that disruption occurs in a way to facilitate the exact product texture desired. This may require some experimentation. There are cases where a semi-gelled structure is sought and in those cases mixing during cooling is often acceptable. One interesting example is the use of ␬-carrageenan to suspend cocoa powder and also provide some mouthfeel in chocolate milk. If there is no mixing during the gel formation stage, the cocoa powder will completely settle out. If the product is mixed during cooling, the ␬-carrageenan will be able to begin to suspend the cocoa as its weak gel begins to form. In this case the disruption of the gel by mixing is not a negative since the texture and stabilizing functionality that is desired is achieved.

Tip Five: Gelling Hydrocolloids—The Influence of Cations Cations are needed for gelation of many hydrocolloids. Those requiring heating and cooling simply need adequate amounts of the appropriate cation to fully gel. Some cations may be present in the hydrocolloid powder, some in the other ingredients used to make the food, and some may be added to ensure that an adequate amount is present. Generally, enough should be added to get maximum gel strength, especially if it is a gelled product. If the gel is too strong then it is more economical to reduce the amount of the hydrocolloid used than to have the hydrocolloid starved for gelling ions. An exception to this principle is when a semi-gelled-type product is sought. This type of product would generally be not seen as a fully gelled product but as something pourable, such as a sauce. However, some

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linkages used in gelling are allowed to occur to take advantage of the thickening and stabilizing properties of the semi-gelled hydrocolloid. In the case of sodium alginate, calcium is needed, but no heat, to form a gel. However, calcium also inhibits solubility, and therefore either the calcium must be added after the alginate has solubilized or the calcium must be bound using a sequesterant to allow the alginate to first dissolve, or the calcium can be added in a low solubility form where it slowly releases, mostly after the alginate is dissolved. Once the alginate is dissolved, the calcium may be added in a quickly available form or a slowly available form. The former includes calcium chloride and calcium acetate. The latter includes tri- and dicalcium phosphates. Intermediate is monocalcium phosphate and calcium lactate. If a quick reaction is desired then the product must already be in some mold (such as onion rings) or there must be no worry about a broken gel (such as imitation fruit pieces). If enough time is needed for the food product to be mixed and pumped then a slow-release calcium is used, such as for fruit fillings.

Tip Six: Hydrocolloid Functionality—Texture Hydrocolloids have an impact, whether desirable or undesirable, on stability, texture, color or appearance, and flavor of the foods in which they are utilized. Hydrocolloids are generally added to a food to have a decisive role in one or both of the first two parameters. The goal should be to have a positive or neutral impact on all four parameters. In terms of the range of texture, hydrocolloids may be used to impart the characteristic texture of the food or be added for stability with the desire to have no noticeable impact on texture. If the goal is to impart a specific texture then this texture should first be defined, and second measured in some way. Now, of course, food comes in a wide range of textures from thin liquids, to thicker but pourable liquids, to solid foods of many different types. Hydrocolloids are often used to make liquids thicker and even to give fairly thin liquids, such as chocolate milk or eggnog, a noticeable mouthfeel. Solid gelled foods are also frequently given their characteristic texture using hydrocolloids. A characteristic texture may be the texture of a good prototype or a competitor’s product that is being matched. The first step is to establish what will be the “gold standard” to be matched. The second step requires

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that by taste testing and/or instrumental testing this gold standard’s texture must be measured in ways that are reproducible. This allows newly developed sample prototypes to be accurately compared to the gold standard. The third step is to figure out what hydrocolloid or blend of gums will allow this texture to be achieved.

Tip Seven: Hydrocolloid Functionality—Stabilization Stabilization, with or without contributing to important textural parameters, is a prime reason why hydrocolloids are used in foods. Stability can often be defined best by a lack of negative effect: the food product does not fall apart. Loss of stability can be seen in a number of common dilemmas. These include separation of the product into phases, including something dropping to the bottom or separating to the top of the food. Separating components can be gaseous (foams), liquid (oil or aqueous layers), or solid (particulates or even a solid lump). Sometimes there is one main source of separation, and other cases involve multiple problems. To best understand stability, it is necessary to fully understand instability. The food scientist will comprehend what makes the product stable by pushing at the edges of stability to see when and how an unstable product could occur. The advantage of this is that if problems should occur in the future in plant production, the scientist will have a list of common unstable prototypes and how these were made using deviations of the hydrocolloid levels. It is always good, for example, when 0.5% of a gum is used in a food to know how the product would look at 0.4%, 0.3%, etc., especially testing to see when the product would not hold together, and how it would separate. It could even be the source of new product ideas. What about a drinkable pudding? Another potential problem with hydrocolloids being used to stabilize foods is overstabilization. This condition is caused by using too high a level of gums in a product, causing it to become too gummy, too firm, or in some other way too strong in texture. There are two approaches that can be taken to gain a more equitable texture while retaining full stability. The first is to lower the gum level or levels until the texture is appropriate and determine if the stability is still adequate. In many cases much of the gum used is not even necessary to achieve stability.

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If this does not work then the use of a new stabilizer system may work to bring about full stability while not causing an overstabilized texture. Too high a gum level can also cause the product to fall apart and separate because some bonds become too strong and therefore disrupt the overall equilibrium of forces holding the product together. A typical example of this concept is an increase of aqueous syneresis, where water is squeezed out of a gelled matrix. Again, when this type of instability is present, it is useful to consider lowering the level of the stabilizer system to determine if improvement is possible while also avoiding introduction of new stability concerns. It can be a balancing act but is often not that difficult once the overall philosophy is adopted that both too little and too much of these powerful hydrocolloids can cause problems in the food, and therefore the optimum middle level should be sought.

Tip Eight: Hydrocolloid Functionality—Color or Appearance Hydrocolloids are most often used to provide intentional effects on texture and stability. But hydrocolloids can have noticeable effects on the color and appearance of foods, either intentionally or nonintentionally. These effects can be perceived as both positive and negative depending on the desired food parameters and which hydrocolloids are utilized. Let us review some major color or appearance effects caused by gums. One major effect is the increase in opacity in foods that can be caused by hydrocolloids. In some cases this is due to insoluble particles found in the gum powder. Microcrystalline cellulose is completely insoluble and has the greatest effect in increasing opacity. If the desired product is a clear beverage, the opacity will be a negative, but in many products opacity is sought, especially if the product is a low-fat version of an established product. Removal of fat can reduce the opacity of foods, for example, in coffee whitener. If the food product is considered of best quality when it is transparent, then transparent versions of several gums are available, including sodium alginate, xanthan gum, and carrageenan. For these gums the insoluble components are removed during processing. If a gum is not fully dissolved then this can be an additional source of insoluble particulates in the food product and therefore achieving full solubility is important from an appearance as well as textural point of view.

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Opacity can also be caused by increased air incorporation, which gums can also contribute to. This can be either desirable or undesirable. If the latter, then the mixing procedure can be altered to minimize air incorporation. Gums can contribute glossiness and sheen to foods, which can be a strong benefit. The natural brightness of the foods can be accentuated this way. This is true of various sauces, fruit fillings and glazes, and many gelled products. Gums can provide an inherently positive benefit, and when compared to alternative texture providers such as modified starches, the contrast in quality can be staggering. The hydrocolloid-stabilized products are often seen to be much more bright, glossy, and full of rich, natural color than pure starch alternatives.

Tip Nine: Hydrocolloid Functionality—Effects on Flavor Flavor effects are somewhat parallel to effects on color and appearance. Most of the time, the gums are added for reasons other than flavor, but flavor can be impacted. In most cases, flavor will be somewhat suppressed by the use of gums. This can be a negative effect when flavors are added or are naturally present in a food. Some of that flavor will be suppressed, requiring the use of additional flavor. It can be a positive effect when flavors are desired to have less impact, such as acid flavor in salad dressings. In this case, flavor suppression is helpful to allow the product to be less harsh. Since a thick product requires something to make it thick, the question is not whether flavor suppression occurs but how much is acceptable and to use appropriate choices among hydrocolloids to achieve the best product. As with color, starch tends to have the most flavor-suppressing effect, and therefore substitution by the much lower levels of gums needed tends to cause a large increase in flavor perception. In many cases this is a big positive effect, but in some cases the starch suppresses undesirable flavors. Also, among hydrocolloids there is a wide range of flavor suppression. These are best explored experimentally since it is not simply a matter of more or less flavor, but flavor nuances as well. Certain components of a flavor profile may be suppressed more or less than other components. A comparison of four or five gums in a food system will quickly indicate the differences in flavor release caused by the various gums.

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Tip Ten: Using Hydrocolloids—Basic Tests Hydrocolloids can be complicated to completely understand and use most effectively. One danger is that one or two gums, the easiest to use, will be used again and again in all applications. Product quality and cost savings may both be sacrificed by this approach. It is prudent to take steps to learn about all the major hydrocolloids, at least those that are used in the specific food where product development efforts are focused. Learning about hydrocolloids can occur on many levels including observing the effects on functional properties and stabilities of foods with various hydrocolloid types and levels. But it is a simple process and well worth the investment of research time to make up pure solutions and/or gels of various hydrocolloids. Simply making up 1% solutions or gels of a number of hydrocolloids in water, or in some cases milk, can be very instructive. Observe the appearance and color of the solutions or gels. Then compare the textures and flavors of the hydrocolloids. Is the texture long or short; that is, is it like jam (long textured) or does the liquid break from itself quickly and cleanly (short)? What kind of mouthfeel does each of the gums provide? Is this the texture desired in the food product itself? It is also interesting to check stability properties such as suspending ability by adding some spices or other particulates and determining the ability of the gums to stabilize emulsions by adding oil and mixing the oil into the aqueous phase to generate an emulsion. A day spent in the laboratory with the above-mentioned assignment would add immensely to the practical understanding of the world of hydrocolloids. It is true that within a food system there are a myriad of sometimes complex interactions. At the root of it all, however, are the hydrocolloids and their immense effect on the water within the food.

Tip Eleven: Using Hydrocolloids—Single Gum versus Multiple Gums Although it may be a challenge to fully understand one hydrocolloid in a food system, it is often desirable to use a combination of gums in a food product. Before discussing how to approach research and

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product development with two or more gums in a food product, let us quickly review some of the primary reasons for using multiple gums in a formulation. Four of the most common reasons are cost, synergy, serendipity, and quality. For cost a common rationale involves using a highly effective gum at a low use level to give some needed stabilization to a food and then adding onto that a less expensive gum to fill out the requirement for viscosity and texture. Several gums are synergistic with other gums, meaning that the net viscosity or gel strength, when the two gums are used together, is greater than would be expected from the additive combinations of each gum. The gums form an interaction that creates a more effective three-dimensional network to structure water. Xanthan gum is synergistic with guar gum and locust bean gum. Konjac is synergistic with carrageenan, xanthan gum, and putatively alginate. These are some of the most common examples. Often synergistic gums are most synergistic at a one-to-one ratio with each other. Serendipity is used to explain that in the real world many prototype formulations are tested with various combinations of gums and one seems to work better than all the others. So this combination is used in the final product. In one case a product development manager tried two complex, but totally disparate, approaches to develop a specialized type of frozen pancake batter and neither was totally acceptable. Finally, he mixed the two different batters together and found that to be a good final product. This blended formulation had 30 different ingredients including several hydrocolloids. It was probably not an optimized formulation, but it worked, and time constraints dictated that the research and development time was ended and this became the final formulation. Quality approaches with multiple gums are generally more sophisticated and are practiced by those who understand the nuances of gums more proficiently. Costs, synergies, desired textures, and stabilities are all considered during product development to come up with what is hoped to approach an ideal formulation. Costs are minimized, synergies are maximized, and stability is very good but not at the expense of desirable texture being sacrificed. A common theme in many of these sophisticated formulations is that a gum, which might be an excellent stabilizer, but not ideal for textural parameters, such as xanthan gum, is kept at a set low level where stability is assured but texture is not compromised.

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To begin to approach this area of research, the following ideas may be helpful. To understand synergies, and indeed any gum combination, make up simple model systems in water to better observe the differences in viscosities, textures, gels, and stabilities. From a cost point of view, get current and accurate pricing of all the major hydrocolloids and make cost in use comparisons. Molecular weight and viscosity are often correlated for a specific hydrocolloid. Very low-viscosity grades may be more expensive to buy due to extra processing costs to degrade the hydrocolloid to a much lower molecular weight. Very high-viscosity grades may be more expensive because only a portion of the raw material used for that gum may yield a very high viscosity and also it is more difficult to gently process it in such a way as to maintain absolute maximum molecular weight. The low- to middle or high-viscosity grades for a specific hydrocolloid are often priced about the same since the raw material costs and processing costs are similar for these grade ranges. The issue is not cost per kilogram however, but cost to make a say 300 cP viscosity solution. Since the middle or high grade requires a lower amount to make a 300 cP solution than the lower viscosity grade, it tends to be more cost-effective to use in the actual food product than the lower viscosity grades. Rather than using pure serendipity to find the best prototype, it is best to use a systematic approach in product development. If it is decided to use two or three gums in a series of prototypes, vary the ratios of the gums in a systematic way to determine the whole panorama of textures and stabilities that are possible. This is better than a typical approach often used where some guess is made of what good use levels may be for the gums in a formulation and then these are tweaked up or down as prototypes are made and found defective in various ways. The quality approach can also be done in a systematic way. For example, the minimum level of a good stabilizing but poor texturizing gum can be ascertained in tests. Once the minimum level needed for stability is determined then that gum is set at that level and the other gums are altered to get the best texture. Of course, for this minimumlevel test to be accurate, the other gums must be present in sufficient quantity to give a texture or viscosity similar to the final desired product. Similarly, the maximum level of a low-cost gum can be determined before textural and other product quality considerations dictate that its level has gone too high.

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Tip Twelve: Using Hydrocolloids—Substitution of Gums for Starch Modified starch is generally of low cost on a cost per kilogram of product basis, but the use levels of starch are much higher than of gums. In addition, starch will generally cause a gummy mouthfeel, be found to be flavor suppressing, and often affect the color or appearance in a negative way. Often it is best to think of starch as a low-cost hydrocolloid, which it is, that can be useful to provide some base viscosity or gel strength but whose use level must not be allowed to go too high to avoid adversely affecting product quality. Fortunately, although gums are more expensive on a per kilogram basis, the cost in use is much more comparable to starch and sometimes lower. This is because gums can often substitute for starch on a onefor-ten weight basis. For example, in the fruit pie filling formulations in Table 1.1, it is seen that the pure starch formulation uses 5–6% starch to provide adequate gel strength and some boil-out stability during baking. But the sodium alginate-containing formulation drops the starch content Table 1.1. Alginate versus starch in pie fillings. Fruit Pie Filling: Starch

Weight (%)

IQF fruit Corn syrup Sucrose Cornstarch Total

65.0 19.0–20.0 10.0 5.0–6.0 100.0

Fruit Pie Filling: Alginate and Starch

Weight (%)

IQF fruit Corn syrup Sucrose Cornstarch Sodium alginate (800 cP) Tetrasodium pyrophosphate Dicalcium phosphate, anhydrous Total

65.0 22.4–22.5 10.0 2.0 0.3–0.4 0.1 0.1 100.0

Source: Guaranteed Gums (2007). IQF, individually quick frozen.

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down to 2% while only using 0.3–0.4% sodium alginate to produce the same gel strength and far superior boil-out protection. Also, the alginate product has much better flavor release (due to its lower use level), is not gummy, is clearer, and has excellent sheen. Briefly, we can therefore summarize the major concepts when substituting gums for starches. First, there is an order of magnitude difference in use level. Second, costs therefore tend to be similar on a use level basis and perhaps somewhat less for the gum. Third, stability is often better for the same texture or gel strength. Fourth, the overall appearance and desirability of the product is often improved due to better texture, less pastiness, combined with greater clarity, sheen, and improved flavor release. This can allow the use of more cost savings by some reduction in added flavors and flavor-providing ingredients.

Tip Thirteen: Using Hydrocolloids—Benchtop Product Development Although benchtop product development is not usually done in the way that is recommended here, this method ensures that the full functionality of hydrocolloids will be understood and appropriated in the food system where the gums are being utilized. The first step is to guarantee the gums can be fully functional by making sure they are fully dissolved and have all the other key conditions such as sufficient heat and/or specific cations for maximum functionality. The goal should be to guarantee the gums are fully functional and not worry about making the food product in the most efficient manner. That will come later. Mixing, heating or cooling, and cations are the three areas that must be focused on. Mixing may require premixing the gum by itself to ensure that the gum is completely dissolved. Also, it may require using much higher shear that is normally used, but be sure not to allow air to be whipped in unless this is desired for the food product being made. In addition, it may be a good idea to allow a much longer mixing time to ensure full dissolution. Care should be taken to evaluate the mix after mixing to see if there are any signs of incomplete solubilization. That is one advantage to predissolving the gum in only water—it is easier to detect any lumping. For heating and cooling, be sure the temperature probe or thermometer is completely accurate. This has often not been the case with

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laboratory instruments that have been in use for a long time and not calibrated recently. Especially this is true for older or cheaper instruments. Next, be certain all the mass of product reaches the desired temperature and if possible goes a little above that temperature or holds for a slightly longer period at the temperature if that can be done without sacrificing product quality. Cations use and control is the final key area to ensure complete gum functionality. The first issue is to control cations that may inhibit full solubility of a gum. It is often a good idea to use distilled water to make sure there is no chance of interfering ions in these idealized first tests. After the gum is fully dissolved, for a number of gums, cations are added to allow full gel strength or viscosity. It is important to be sure these added cations are dissolved enough to be available for the hydrocolloid to utilize. In these preliminary tests, it is a good idea to add more than the theoretically required amount of cation to ensure a sufficient amount. Once this idealized prototype is made where the gum’s functionality is fully maximized, it is necessary to thoroughly evaluate the prototype, especially for textural parameters, both by instrumental methods and by taste testing. If more or less gum is indicated by these testing methods then the next prototypes can be made in the same careful way. Once the prototype is close to what may be required from a textural and stability point of view, the next steps of finding the most efficient formulation and processing procedure can be undertaken. At this point it is useful to consider the plant processing procedures and think about limitations in the plant operations, especially in the area of mixing. Then it is useful to plan a benchtop procedure that will best mimic the plant operations. The good thing is that it is known what the product will look like if the gum is allowed to become fully functional. The rest of the product development is to take the idealized procedure developed to allow maximum gum functionality and gradually adjust it to allow a simpler operation for the plant while maintaining full functionality. This should be done step by step. For example, cations can be reduced to the point where the gum starts to lose some functionality. At this point add back enough ions to allow full functionality. The mixing time and intensity can be reduced, and each time the product made can be compared to the gold standard to determine the minimum mixing time and intensity required.

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Tip Fourteen: Using Hydrocolloids—Scale-Up to Plant Production Scale-up to pilot plant and then to plant production can be tricky for any food product, and where hydrocolloids are used as ingredients, it should be done carefully. There do not have to be any difficulties, but certain precautions are important. It is best to plan and proceed systematically. Among the steps that may be critical involving hydrocolloids include incorporation of the gums, mixing, any ion addition step, heating, cooling, holding, and packaging. The thing to remember is that at the benchtop scale several of these steps are easily controlled and some are hardly even thought about. One benefit of the benchtop is that often everything that is happening is easy to monitor and adjust, but not so in the plant. For example, unwanted air incorporation can be easy to see and adjust on the bench but may not even be observed in the mixing tanks used in the plant. Incorporation of the gum is what first should be considered. When and how to do this is important as well as what should be done before and what should be done after concerning other ingredients. Avoiding lumping by premixing with another dry ingredient or high shear is important. Also, sufficient time must be allowed for the gum to fully dissolve. In some cases the mixing time must be increased in the plant compared to benchtop tests because the mixing may not be as intense or efficient. If sequestrants, such as phosphates, are added to help the gum dissolve, these should be added before the gum or at least with the gum. For the heating and cooling steps, it is important to ensure that the entire mass of product reaches the maximum heating temperature and also the final cooling temperature. The holding and packaging steps are very critical to plan for and monitor during plant production. During benchtop tests, these steps are often done with no delay, but in the plant, emptying out a large mixing tank and packaging the product may take many minutes. If the product begins to gel or set up during or shortly after cooling, or after adding some cations, then it must be ensured that the entire product is packaged before this occurs. Otherwise, the gelling product will be chopped up and may permanently ruin the texture and stability. If the product gels with calcium, such as with sodium alginate, then adding a less soluble calcium salt will allow the extra time needed for

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the product to be fully packed before gelation becomes an issue. If the product gels by cooling, then packaging the product before fully cooled may alleviate premature gelation.

Tip Fifteen: Using Hydrocolloids—Plant Troubleshooting This tip deals with the situation where everything has been going well in plant production for quite some time and suddenly a problem or problems appear. What is to be done in these cases? The most important step is to collect all relevant information for both the ingredients used in the problem batch and all the data recorded and information available from each unit processing step. From the processing point of view, it should be determined if any new employees operated any equipment, if processing times and temperatures were altered for that lot, and if any equipment showed any signs of malfunction. Instruments that record temperatures and other parameters should be carefully checked to determine if any anomalies occurred. On the ingredient side, even though texture or stability may be affected, it should not be automatic to assume that the prime textural and stability components, hydrocolloids, are always the culprit. Still, the first step when texture or stability problems occur is to check all the ingredients, including the hydrocolloids, and determine if any of them had a new lot that was first used in the problem production run. If the problem in the plant coincides exactly with a new lot of hydrocolloid being used in that batch, the hydrocolloid should be investigated. The first step is to look at the quality assurance (QA) data for that lot, both that provided by the manufacturer and any that was generated by the customer’s QA department. At the same time when this sheet of data is evaluated, also pull out the data from several of the previous lots for comparison. It is unusual for a manufacturer of gums to ship out a lot that is out of spec. Therefore, it is helpful to determine first of all if anything is atypical about the lot, even if it is still within specifications. For example, one of the oldest and largest alginate manufacturers sent a lot of sodium alginate to their largest customer a few years ago. The sauce being made was too thin even though the viscosity of the alginate was in spec. But someone noted that the moisture content was extremely low, about 6%. The specification specified less than 15% moisture, and most previous lots had 12–15% moisture. It turns out

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that the viscosity of the lot was low, and the production people in the alginate plant decided to overdry the product to squeeze it into the right viscosity. But this caused extreme dusting problems and damaged the hydration ability of the alginate when used in the sauce. The main point is to look for unusual data, even data that look too low, as in this case. Incidentally, one-way specifications should be avoided, as this case typifies. Instead of less than 15% moisture, it is better to specify between 10 and 15% moisture, for example. What if the hydrocolloids were all used in previously acceptable production batches? In that case, look at any other ingredient that may have been from a new lot. Also, check the water source and water purification system for potential problems. It is not uncommon for carbon filtration systems to become overloaded at times in water purification systems, and thus improperly treated water may have been used in the production batch. The water may have then been the source of higher ion contents being added to the mix, which could have inhibited some hydrocolloids from hydrating. Was the clean in place (CIP) system not used correctly allowing some iodine or chlorine to enter the batch? These types of strong oxidizing agents can damage macromolecules in the food system and cause unstable final products. Good troubleshooting will almost always determine where the problem occurred so that the situation can be remedied to avoid future problems.

Reference Guaranteed Gums. 2007. Newsletter, August 2007 Issue, p. 2.

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Chapter 2 Hydrocolloids in Salad Dressings Alan H. King

This chapter covers the various types of salad dressings used in the United States and Canada, including typical ingredients, manufacturing equipment, and how to assemble the different products. The common functions of dressing stabilizers are addressed, along with a discussion of the major stabilizers used, usage levels, and benefits versus liabilities for each stabilizer. Tips are presented on determining the proper hydrocolloid level, how to achieve the desired shelf life, and rheological properties for dressings, as well as some pitfalls to avoid. To begin with, let us consider the various types of salad dressings that are marketed in the United States and Canada. They include spoonable dressings such as mayonnaise and salad dressing, pourable dressings with shelf-stable emulsions and also temporarily stable emulsions or separating dressings, and dry mix dressings for home or restaurant preparation. There are two types of pourable, shelf-stable dressings, “fine” and “coarse” emulsions. Examples of “fine” emulsions are regular French dressing and ranch dressing. Examples of “coarse” emulsions are Catalina French and Golden Italian. Italian dressings are made in four different forms: creamy (a “fine” emulsion), golden (“coarse” emulsion), separating, and dry mix, which may be either of the separating or stable emulsion type. Obviously there is a plethora of dressings available, and to add another order of complexity, all of these dressings are made in low-oil or no-oil forms as well. Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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Real mayonnaise is a standardized product that requires at least 65% oil and does not allow any hydrocolloid stabilizers. (See the following web site: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/ cfcfr/CFRSearch.cfm?fr=169.140.) However, lower oil dressings of this type (i.e., spoonable), including “salad dressing,” will contain hydrocolloid stabilizers and oil levels from 0–55%. The only hydrocolloid allowed in “standardized salad dressing” is starch, and it must have at least 30% oil. (See the following web site: http://www.accessdata. fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=169.150.) French dressing is another standardized product (i.e., pourable dressing) which must contain at least 35% oil and may contain various hydrocolloids. (See the following web site: http://www.accessdata.fda.gov/ scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=169.115.) Of the regular (i.e., full oil) pourable salad dressings, the top 12 most popular flavors are listed below. Top 12 Popular Flavors (Regular Varieties) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Ranch Blue cheese Italian (separating) French Thousand Island Caesar Honey Dijon Poppy seed Balsamic vinaigrette Olive oil vinaigrette Red wine vinaigrette Italian (creamy)

Flavor Trends—Association for Dressings and Sauces, November 2004.

Typical Salad Dressing Ingredients Water, oil, and vinegar are the major ingredients of “regular” salad dressings. Additional important ingredients include salt, spices, hydrocolloid stabilizers, emulsifiers, chelators, flavorings, and colors. The oil component is normally a vegetable oil, such as corn, soy, or canola.

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Vinegars may be of various types like white (essentially acetic acid), wine, cider, etc. Often vinegar used in commercial production will be of 100 grain strength (i.e., 10% acetic acid). Emulsifiers may be “natural” or “chemical.” Examples of “natural” emulsifiers would be lecithin and cholesterol (in egg yolks) and mustard powder (dressing grade). Examples of “chemical” emulsifiers would be polysorbates 60 and 80—usually of hydrophilic/lipophilic balance (HLB) 12 or higher for pourable dressings. Chelators such as ethylenediaminetetraacetic acid (EDTA) are used to extend the oil shelf life by chelating heavy metal ions, which promote oil rancidity.

Typical Equipment for Making Salad Dressings While assembling pourable dressings, one should guard against forming vortices in mixing tanks since they tend to incorporate air, which is anathema to dressings. Air incorporation leads to many negative consequences including emulsion separation, unsightly striations, slack fills, and oil rancidity. A horizontal, variable speed, squirrel cage-type mixer in the bottom of the mixing (premix) tank provides a rolling action with no vortex and little if any air incorporation. Dixie agitated premix tank, 100 gallon, 29 dia × 41 deep w/6 deep cone bottom. 316 SS triple squirrel cage agitation. Another important point is the need for all stainless steel equipment. The use of any brass surfaces that contact the dressing will result in copper ion introduction and very rapid development of oil rancidity. Most stable emulsion, pourable dressings, as well as spoonable dressings, are passed through colloid mills to make the oil droplets as small as possible and thus contribute to increased shelf life, viscosity, and homogeneity. Colloid mills allow for much faster throughput than homogenizers and thereby increase production rate and require much less space than comparable capacity homogenizers.

How to Assemble Dressings Stable, pourable emulsions will be considered first. The “minor” ingredients (i.e., low percentage ingredients such as emulsifiers, spices (except for salt), color, flavors, chelators) should be

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added to the water first. Then any stabilizers (e.g., a 3:1 oil to stabilizer slurry, or dry mixed with 5–10 parts of sugar) should be dispersed and the dispersion should be added to well-agitated water in order to hydrate the stabilizer. Mixing under high shear conditions should be continued (for 3–5 minutes) to hydrate the stabilizers before addition of remaining ingredients. It is very important to completely hydrate the hydrocolloid stabilizers before addition of water competitors like vinegar, salt, sugar, etc. since these competitors may prevent further hydration of incompletely hydrated hydrocolloids! An additional minute or 2 of high shear mixing at this initial stage will accomplish far more than 10–20 minutes of mixing in the presence of competitor ingredients! Add the ingredients that compete for water, such as vinegar, sugars, and salt, once the gum is completely hydrated. The oil is normally added last, under high shear mixing. It should be added slowly at first, then more rapidly as it becomes incorporated into the emulsion (but not so rapidly as to allow “pooling”) to form stable, “fine” emulsions. Note: “coarse” emulsion dressings require relatively low shear mixing under carefully controlled conditions and the absence of o/w emulsifiers. Once the formation of the emulsion in the premix tank is complete, it is normally passed through a colloid mill, with the exception of most low oil/fat-free and “coarse emulsion” products. The last step before packaging would be the addition of any particulates that should not go through the colloid mill (e.g., chunks of blue cheese, bell peppers), mixing just enough to insure uniform dispersion throughout the dressing. Separating dressings—The aqueous phase of separating dressings is assembled similarly to that of stable emulsion dressings, but the oil is held aside and added as the second stage of a two stage filling operation. In other words, the completed aqueous phase is filled into bottles first, followed by the oil phase that is filled on top of the aqueous phase in order to create minimal mixing between the two phases. Spoonable dressings differ from “fine emulsion,” pourable dressings, as in that most of the viscosity comes from starch. A modified starch, designed for salad dressings, should be used. The starch must be cooked (gelatinized) to form a starch paste, which must then be cooled before assembling the rest of the dressing. Any additional hydrocolloids (gums) may be added to the starch slurry before cooking, using typical

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dispersion techniques, or hydrated in a portion of the formula water and added as a solution to the starch paste after cooling. Remaining ingredients are added much the same as for the “fine emulsion,” pourable dressings, with oil again being the last ingredient, followed by milling. Pregelatinized (or instant) starches are also available that do not require cooking and are treated like other cold water soluble hydrocolloids (i.e., require proper dispersion methods to prevent lump formation). Dry mix dressings may be either of the separating type (standard Italian dressing) or stable emulsion type. In either case, the hydrocolloid particle size (mesh size) is very critical and particle size of other dry mix ingredients is also important. A fine mesh hydrocolloid (e.g., 200 mesh) is normally required to achieve rapid hydration of the gum under minimal shear conditions (such as handshaking in a cruette with vinegar and salt present). The mesh size of other ingredients, such as sugar and salt, are important to provide sufficient surface area to act as good dispersants for the hydrocolloid. This becomes especially important with fine mesh gums, because they tend to form lumps much easier than more coarse mesh gums, so efficient dispersion is required.

Typical Functions of Hydrocolloid Dressing Stabilizers Viscosity is one of the major functions of dressing stabilizers, which is related to suspension of particulates, emulsion stability, pourability, etc. Just about all hydrocolloids will provide significant initial viscosity, but long-term stability of viscosity is crucial. Often these dressings must maintain a stable viscosity for up to 1 year, or even longer, after manufacture. This means that only those hydrocolloids which have sufficient acid, and sometimes temperature, stability, can be used when such longterm shelf life is needed. The most acid stable of the gums are xanthan gum (XG), gum tragacanth, propylene glycol alginate (PGA) and microcrystalline cellulose (MCC). Generally speaking, neutral gums like guar and locust bean gum produce good viscosity initially but have relatively poor long-term acid stability. Of course, once viscosity drops due to acid degradation, then the dressing looses its ability to suspend, the emulsion may start to separate, the color can change, etc. The ability of the dressing to cling nicely to salad greens is another important function of the stabilizer. This not only depends on

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viscosity, but more importantly on rheology, or the specific flow properties of the hydrocolloid stabilizer and hence the dressing. If the dressing is Newtonian-like, it will pour nicely (smoothly), but will not cling as well to the greens as a dressing with a more pseudoplastic rheology. The pseudoplastic rheology is characterized by very high viscosity at rest, and much lower viscosity while being subjected to work (shear, like pouring, pumping). Consequently, dressings with pseudoplastic flow properties tend to cling to the salad very well, since the viscosity is very high while sitting on the lettuce. Rheology is also very important during filling operations, and clean cut off during filling (i.e., lack of “tailing”) is extremely important when filling portion packs and to prevent splashing during filling of larger containers. Again, a pseudoplastic rheology is best for these functions. Suspension of particulates and oil droplets is of course very important and related directly to viscosity and rheology. When hydrocolloid stabilizers are degraded, viscosity drops and suspension properties are also degraded. All of the hydrocolloids will suspend particles, but those with pseudoplastic rheology will be considerably more efficient than those with more Newtonian rheology because their effective or apparent viscosity will be much higher at rest than when being mixed, and therefore can be formulated at considerably lower viscosity values (as measured on a Brookfield RVT viscometer at 20 rpm, for example). Prevent/control separation: This function is also directly or indirectly related to viscosity and suspending power, which is related directly to gum concentration. Once the viscosity drops below some critical value, separation of oil and settling of particles will begin to occur. Of course this phenomenon will be exacerbated at elevated temperatures, and storage of emulsions in ovens (100◦ F, for example) is often used as an “accelerated emulsion stability” test. Maintain/impart color: This function relates to loss of viscosity because this can cause emulsions to degrade. The oil droplets then become larger through coalescence, and that usually means colors become darker. For example, a typical creamy French dressing with a light reddish orange color will change to a deeper color, typical of a Catalina-type dressing, due to the change from a fine, creamy emulsion to a coarser one. Limit calories: Since all hydrocolloid stabilizers, except for starch, are nondigestible, they do not contribute any significant calories,

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especially at typical use levels of under 1.0%. Even some starches (resistant starches) are now available which are minimally digestible. Mouthfeel: Each of the hydrocolloid stabilizers contributes different kinds of mouthfeel, and some are actually used for this purpose. For example, MCC is frequently used in low calorie dressings as a fat memetic, and other hydrocolloids are used to modify the mouthfeel characteristics of starch in spoonable dressings.

Major Dressing Stabilizers—Benefits/Liabilities The hydrocolloid stabilizers that we discuss here are XG, PGA, starches, MCC, and guar gum. Although other hydrocolloids may be used occasionally, these are the major players. XG: Few will disagree that XG is the most versatile of the hydrocolloid stabilizers for salad dressing, especially of the pourable variety. This benefit flows from its rheological and stability properties. Rheologically speaking, XG is best described as highly pseudoplastic, which gives it the superior suspension, cling, ease of pumping and mixing, and excellent filling characteristics, as mentioned earlier. In addition to rheology, XG’s stability toward acid, temperature, and enzymes help to explain why it is the favorite stabilizer for pourable salad dressings. One can prepare emulsions that are stable against separation for 3 years with XG. No other dressing stabilizers possess such long-term acid stability. It also tends to maintain a steady viscosity over a wide range of temperatures, unlike most other hydrocolloids that typically thin with increasing temperatures. The amount of XG needed depends on the type of dressing being produced. Regular oil dressings usually require about 0.25%, separating dressings generally require considerably less, and low- or no-oil dressings need around 0.5%. On the negative side, XG can produce dressings with “gloppy” or “chunky” flow characteristics if used at high concentrations (usually >0.5%). This becomes a problem mainly in low calorie dressings, which require considerably higher hydrocolloid levels due to the increased amount of water that must be stabilized. This brings us to the next hydrocolloid. PGA: Before food approval of XG, PGA was the hydrocolloid of choice for pourable salad dressings. It has the advantages of being quite acid stable (6–9 months in dressing environs), possessing secondary

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emulsifying properties, and a smooth, Newtonian-like rheology. Also, PGA is sensitive to high levels of calcium (a potential problem in dressings containing substantial levels of dairy ingredients), and its heat stability is rather poor. At current prices, it is also considerably more expensive than other choices. In today’s marketplace, PGA is used mainly to modify the rheology of XG (to make it more smooth), especially in low- or no-oil dressings, which require high hydrocolloid concentrations. There is a convenient relationship between XG and PGA viscosity/use level. Two parts of low viscosity, dressing grade PGA, are roughly equal in viscosity to one part of XG in salad dressing formulas. Generally speaking, PGAs should not be used in “coarse” type emulsions, due to their emulsifying properties, which favor “fine” emulsion formation. Modified starches are used mainly in spoonable dressings. These starches are modified to have improved acid and shear stability so that they may withstand high acid and shear conditions encountered during processing and storage. Starches have the advantages of giving the typical spoonable texture, not obtainable from other hydrocolloids, being “consumer friendly” (clean label), being permitted in standardized dressings, and possessing low cost per pound. They are usually digestible and used at concentrations approaching 5%, so contribute calories to the formulas. Many of the starches require cooking to gelatinize them before they can be used in the dressing and are susceptible to degradation under high heat and acid conditions. At the highest usage levels, starches can contribute a pasty mouthfeel and tend to mask delicate flavors. A major difference between mayonnaise and spoonable salad dressing is the “heavier” mouthfeel caused by the presence of starch in the salad dressing. MCC is used extensively as a fat mimetic in low- or no-oil dressings. It contributes opacity (very white) to dressings and can produce starchlike consistency or texture if the levels are high enough (>2%) and so, it is useful in spoonable as well as pourable dressings. MCC possesses good stability to acid, salts, and temperature, so it works well together with other hydrocolloids. MCC also acts as a good suspending agent, due to its thixotropic rheology. Although relatively high shear is needed to develop MCC’s full viscosity, this is normally not a problem when using dressing equipment. For coarse emulsion products, MCC could be problematic and its whiteness would likely change the color from the desired hue.

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Guar gum is the lowest cost hydrocolloid (on a usage level basis). It is rarely used alone in dressings, and is sometimes combined with XG as a means of lowering the total hydrocolloid cost. Under certain conditions, guar and XG combinations provide synergistic viscosity increases, but this effect is markedly reduced as the pH decreases below 5 and as the salt concentration increases, because the synergism is due to hydrogen bonding between the 2 gums, and that effect is significantly reduced as hydrogen and other ion concentrations increase. Additionally, guar has poor long-term acid stability. When used in combination with XG, after a few weeks the guar will start being hydrolyzed by the acid. When that occurs, not only is guar viscosity lost, but any viscosity from the synergism between XG and guar will also be lost. This may result in a significant viscosity loss and subsequent emulsion separation. Heat exacerbates degradation and will further reduce dressing shelf life. Therefore, manufacturers should be very cautious about using guar in salad dressings. Typical Dressing Formulae Typical Pourable French Dressing Ingredients Vegetable oil, soybean Water Sugar, granular Vinegar, white, 10% (100 grain) Tomato paste (26% T.S.) Spices, color, flavor, etc. Salt Mustard powder Xanthan gum

Grams (g)

Percent (%)

382.0 308.0 115.0 100.0 60.0 12.5 10.0 10.0 2.5

38.20 30.80 11.50 10.00 6.00 1.25 1.00 1.00 0.25

1000.0

100.00

Preparation 1. Blend all dry ingredients except for XG and salt, and add to wellagitated water. 2. Slurry XG in 3–5 times its weight of oil.

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3. Add oil/gum slurry to #1 aqueous solution, under vigorous agitation, and continue vigorous mixing for 3–5 minutes. 4. Continue mixing and add tomato paste, color (if liquid) and salt. Mix to homogeneity. 5. Add oil slowly, under continued vigorous agitation. 6. Continue mixing and add vinegar. Mix until homogeneous. 7. Pass dressing through a colloid mill set at 0.25 mm (0.01 ). 8. Fill containers. This dressing uses only one stabilizer (XG) and should possess a viscosity of about 3,500 cP (Brookfield LV viscometer, spindle #4, 60 rpm), pH of 3.6, and aqueous phase acidity of 2.26 (as acetic acid). Unless augmented by other preservatives, the aqueous phase of dressings should typically be >2% as acetic acid to inhibit bacterial growth. Typical Spoonable Salad Dressing Ingredients Vegetable oil Water Sugar, granular Vinegar, white, 10% (100 grain) Egg yolks, frozen Modified corn starch Salt Mustard flour Xanthan gum

Grams (g)

Percent (%)

350.00 319.00 120.00 100.00 55.00 35.00 15.00 5.00 1.00

3.5 31.90 12.00 10.00 5.50 3.50 1.50 0.50 0.10

1,000.00

100.00

Preparation (laboratory) 1. Preblend all dry ingredients and add to the water while mixing and heating to 180◦ F (82◦ C) in a double boiler. 2. Cool to room temperature, while stirring in an ice water bath. 3. Transfer to a Hobart-type mixer with a wire whip. 4. Add thawed egg yolks; mix with a wire whip. 5. Add oil slowly, while continuing mixing.

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6. Add vinegar slowly and continue mixing until smooth.  7. Pass through a colloid mill set at 0.01 (0.25 mm). This spoonable dressing’s main stabilizer is starch, but the level of starch is reduced by the addition of 0.1% XG, thereby improving the texture and stability of the dressing.

Typical Italian Dressing (Separating Type) Ingredients Vegetable oil, soybean Cider vinegar, 5% (50 grain) Water Lemon juice, single strength Salt Spices and flavorings to suit Xanthan gum

Grams (g)

Percent (%)

560.0 280.0 90.0 50.0 10.0 9.8 0.2

56.00 28.00 9.00 5.00 1.00 0.98 0.02

1,000.0

100.00

Preparation 1. Dry blend XG with all dry ingredients. 2. Hydrate dry blend in all available water under vigorous agitation for 10 minutes. 3. Add lemon juice and vinegar. 4. Fill aqueous and oil phases in a two-step process by weight or volume. This should produce a dressing with pH of 4, viscosity of 130 cP∗ (after shaking at room temperature), and aqueous phase acidity of 4%, as acetic acid. (∗ Brookfield LVT, spindle #2, 60 rpm). Note: This separating dressing will only hold together for a few minutes at this low concentration of XG. Higher levels of XG may produce dressings that are stable for considerably longer periods of time but may not separate as cleanly as the low concentrations.

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Hydrocolloids in Food Processing Typical Low-Calorie Italian Dressing Ingredients Water Vinegar, white, 10% (100 grain) Salt Spices, flavors, and sweeteners to suit Xanthan gum Propylene glycol alginate Sodium benzoate Potassium sorbate

Grams (g)

Percent (%)

820.30 150.00 10.00 8.20 4.50 3.00 0.50 0.50

82.03 15.00 1.00 0.82 0.45 0.30 0.05 0.05

1,000.00

100.00

Preparation 1. 2. 3. 4. 5. 6.

Thoroughly blend all dry ingredients, except salt. Add dry blend to available water under vigorous agitation. Mix for 5–7 minutes. Add vinegar and mix until homogeneous. Add salt and mix for 1–2 minutes. Bottle.

This formula should produce a dressing with pH 3.3, viscosity of 720 cP∗ (room temperature), and aqueous phase acidity of 1.6%, as acetic acid. (∗ Brookfield LV spindle #3, 60 rpm). Two gums, XG and PGA, are used. In order to achieve sufficient viscosity with only XG, a dressing with objectionably “chunky” rheology would result. PGA produces more Newtonian flow properties than XG and is used to give the added viscosity needed after the maximum XG level (from a rheological aspect—usually 0.5% or less) is used. Since the water phase makes up over 80% of this dressing, additional preservatives (benzoate and sorbate) are used to allow for lower vinegar levels and better flavor.

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Mayonnaise-Type (7% Oil) Spoonable Salad Dressing Ingredients

Grams (g)

Percent (%)

1163.00 300.00 140.00 112.00 108.00 60.00

58.15 15.00 7.00 5.60 5.40 3.00

Modified waxy maize starch (instant)

55.00

2.75

Salt Xanthan gum

34.00 13.00

1.70 0.65

Flavor, spices, color, etc. (to suit) Sodium benzoate Potassium sorbate, powdered

13.00 1.00 1.00

0.65 0.05 0.05

2,000.00

100.00

Water Egg whites, pasteurized Soybean oil Vinegar, distilled, 100 grain Sugar, granular Microcrystalline cellulose

Preparation (Use a 5 quart Hobart-type mixer, equipped with wire whip.) 1. Add emulsifiers and all dry ingredients (except for salt and sugar), to the water. 2. Dry blend hydrocolloids (MCC, starch, and XG) with the sugar. 3. Add hydrocolloid (HC) or sugar dry blend to the water under highspeed agitation and mix for 5 minutes. 4. Add liquid egg whites and mix until uniform (ca. 1 minute). 5. Add chilled oil slowly, and mix for 2 minutes at high speed. 6. Add the salt and continue to mix. 7. Add vinegar and any other liquid flavors or acids, and mix 3 minutes at medium speed. 8. Optional: Pass through colloid mill at 0.06 . Note: In order to achieve a mayonnaise-like flavor, acidity must be kept as low as possible. Therefore, using a considerably lower vinegar concentration than needed for proper preservation requires the use of

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additional preservatives (e.g., sorbate and benzoate). Since the preserving function of vinegar depends on the amount of undisassociated acetic acid present, other acids (citric or mineral acids, for example) may also be added to lower the pH and make the formula vinegar more efficient in its preserving role. MCC is used mainly as a fat mimetic and to provide spoonable texture similar to starch, but without calories. Both XG and MCC allow for the lowest possible starch level, which contributes to better flavor release and a texture more like real mayonnaise than typical spoonable salad dressing.

Determining the type and level of hydrocolloid (HC) needed 1. The particle size (or mesh size) of the HC needed depends on the type of dressing being produced. For dressings produced with high shear mixing equipment, a “regular” particle size (e.g., 80 mesh) is desirable. For dry mix dressings to be used in home settings, “fine” particle (e.g., 200 mesh) sized HCs are needed, since they are hydrated under very low shear, gentle mixing conditions (e.g., hand shaking in a cruette). This also requires careful choice of other dry ingredients to act as dispersing agents for the fine mesh gums which will have greater tendencies to form lumps. Fine mesh sugar may be required for such applications, for example. 2. To determine how much HC is needed for a particular function, prepare two identical dressings, except that one should contain a significantly higher HC concentration than needed and one should have a significantly lower concentration than needed. Mix the two dressings together in different proportions to create a spectrum of different HC concentrations, measure viscosity values and store them in 100 ml graduated cylinders to observe for particulate settling, oil separation, heat stability, etc. 3. To obtain a desired rheology, a similar method may be used, except this time two dressings are prepared with equal viscosity, but stabilized with different gums possessing differing rheological characteristics. Consider the typical French dressing formula above as an example. This formula calls for 0.25% XG. If a smoother flowing dressing is desired, prepare an equal viscosity dressing with PGA at 0.5% instead of XG. Subsequently, the two equal viscosity dressings

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may be mixed together in different proportions to determine which proportion gives the desired rheology for the dressing. This procedure becomes even more useful when dealing with low calorie/no oil dressings which must use high gum levels, due to the expanded aqueous phase. Rheology becomes an even greater factor in such cases.

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Chapter 3 Hydrocolloids in Muscle Foods James W. Lamkey

There are a number of reasons why meat formulas differ over time and across regions. Economic conditions play a major role in the composition of processed meat products. Economically underdeveloped countries make products that are affordable to the majority of the population, replacing meat proteins with less expensive nonmeat ingredients. Raw material availability is also a major reason for adjustments to formulations. Animal fat, for example, is less available in some countries, requiring formulations to make adjustments for the lack of fat. This is also true in some countries where consumers want the taste and texture of traditional products but do not want the fat. Food safety concerns have also caused processors to reformulate products to withstand treatments that promote a safer food product. Postpackaging pasteurization can cause a high level of moisture loss, requiring the addition of an ingredient that aids in the retention of moisture. Organic acid is being used as an added hurdle for food safety. When adding the sodium salts of these acids, sodium levels approach the upper limit of nutritional labels. When the potassium salt is substituted to adjust for this increase in sodium, there may be effects on other ingredients in the formula, requiring a substitution to recover the taste and texture desired. As the industry grows and markets reach beyond domestic borders, formulations will need to meet the requirements of the target regions.

Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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Ingredients added to meat can either enhance meat protein functionality or be a supplement to meat protein functionality. Proteins are the primary component in meat that aid in the retention of moisture. However, in the area of processed meat, the proteins are asked to retain more moisture than normally contained within the protein. The proper use of ingredients, as well as optimal process conditions, will enhance the proteins ability to retain moisture. In many cases, however, this is not enough to meet the desires of the processor. Other ingredients are then added to aid in the retention of the excess moisture, but the selection is based on cost as much as the overall contribution to the end product. In the selection of an ingredient for a particular product, a processor must consider how these ingredients perform in the presence of other ingredients, as there becomes a competition for moisture. When one ingredient has a higher affinity for water, but cannot tightly hold the water during cooking or heating, there can be a noticeable reduction in the cook yield. Optimal use of the ingredients will give the best overall functionality at the best cost. In some cases, when the ingredients are not added properly, there will be a reduction in moisture retention. Ingredients react and perform differently in meat applications. Information in Table 3.1 allows us to differentiate between ingredients on the basis of degree of activity in the food system. Starches and some gums are considered highly active because these ingredients obtain their full functionality during thermal processing. Soy protein isolate, on the other hand, aggregates during the initial stages of processing which is set during thermal process. These matrices assist in the retention of moisture and contribute to texture. Salt and phosphate are the most common ingredients added to meat products, which act on proteins to enhance functionality. Prior to the advent of refrigeration, salt was used at levels that limited the growth of microorganisms and therefore extended the usable life of the product. Most of the proteins responsible for moisture retention are salt soluble. Salt, and specifically chloride ions, adapts the protein for greater moisture retention by masking some of the positive charges on the protein molecule. This in turn gives the protein a stronger negative charge, increasing repulsion within the molecule, opening up the structure for moisture retention. In the case of further processed meat products, salt soluble proteins are extracted and made available for water and protein interactions that enhance texture. Alkaline phosphates, as the name

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Table 3.1. Characterization of biopolymers on the basis of degree of activity. Degree of Activity

Type of Biopolymer

Nature of Activity

Highly active

Starches, gums

Moderately active

SPI, wheat gluten, egg whites

Slightly active

Milk proteins, pregelatinized starches

Inactive

Cellulose (unmodified)

Inactive

Oil/fat

Thermally induced activation, formation of elastic globules No thermally induced activation, strong water binding, and formation of elastic mass upon hydration Moderate water binding, formation of nonelastic mass Water binding but no thermal activation No water binding or thermal activation

SPI, soy protein isolate. Adaptation from Lee 2002.

implies, increase the pH of the environment which in turn enhances the protein’s ability to hold water. In the presence of phosphates, actomyosin is dissociated into the primary components of actin and myosin through the action of pyrophosphate. In fact, salt and phosphates work synergistically to improve the moisture binding and texture enhancing characteristics of meat proteins through this action because myosin is higher in water binding capacity than is actomyosin and salt helps to extract the protein to further improve functionality. Although meat proteins are very functional, there are times when meat products can benefit from the addition of other ingredients. These additional ingredients do not enhance protein functionality but work with the proteins to help retain moisture and modify texture. Starch is the most widely used carbohydrate in the meat industry on a global basis. Both cost and functionality are primary reasons for its wide use. In the United States, starches are limited to 3.5% on the basis of their weight and can be used in combination with other hydrocolloids as long as the combined total does not exceed 3.5%. In some regions,

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such as Latin America, Asia, and Eastern Europe, it is not uncommon to see formulations with 5% or more starch. The type of starch used in meat products is primarily dependant on what is available in the region. Starches are obtained from a variety of sources with a wide variety of functionalities. Corn, potato, wheat, tapioca, and rice starch are the most common. The primary functionality of starch is to bind water, provide various degrees of freeze/thaw stability, and contribute to texture. Starch’s functionality is derived from its ability to swell and take on water, like many other hydrocolloids. The swelling of the starch occurs during the heating stage making it a highly active biopolymer. One of the differentiating features of starches is the amounts and ratios of amylose and amylopectin. Starches with high amounts of amylopectin, such as waxy maize, will not gel or synerese after gelatinization. High amylose starches will form very stiff gels. The modification of starches is done to enhance or quell inherent properties. In some cases it is modified to control texture, viscosity, heat tolerance, or freeze/thaw stability. Most of these modifications are based on performance in a water system without proteins. In meat applications, there are indications that starches do not become fully soluble under typical processing conditions and therefore the modification is not fully manifested in a meat application. Starches have been found to be synergistic with other hydrocolloids, one of which is carrageenan. Carrageenan is a hydrocolloid obtained from various species of red seaweed and can help processed meat products retain moisture. Carrageenan is available in many forms; however, the primary characteristics of which a processor should be aware of are type, composition, and concentration. There are three primary types of carrageenan: kappa, iota, and lambda. Very strong and brittle gels characterize ␬-carrageenans. Iota, on the other hand, is less strong and more elastic. ␭-carrageenans do not gel and are used primarily for suspension of particulates in sauces and dressings. Kappa and iota are the carrageenans showing the most benefit in meat applications, as water managers and texture modifiers. Lambda, like most cold soluble hydrocolloids, cannot manage the water in which they are soluble, and therefore shows little benefit in processed meat products. The composition of a carrageenan used in meat processing can widely vary. Of the components most often seen in a blend, the most common

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are carrageenan, potassium chloride (KCl), sodium chloride, sugars, and various other hydrocolloids to include like locust bean, guar, and xanthan. Some of these ingredients show an advantage, or synergy, when included in water gels, but may not show the same benefit in meat applications. The presence of ions and the insulating effect of the proteins subdue any synergies that may be possible. KCl is the most common ingredient in carrageenan as potassium is required for gelling of ␬-carrageenans. KCl is also used for the precipitation of carrageenan in gel press applications. Therefore, KCl is commonly a component of the carrageenan molecule and is necessary for proper functioning. Regulations specify that the ash content of carrageenan cannot exceed 35%. If KCl is the only added component in the blend, levels resulting in ash contents above regulatory limits require the labeling of KCl. In some cases, however, carrageenan is blended with additional KCl for improving water gel firmness. Up to 20% of the carrageenan weight can be added to KCl for water gel strength improvement. Adding KCl at concentrations above 20% of carrageenan reduces gel strength due to a dilution effect. An increase in gel strength with added potassium, however, is only seen in water gel applications and not necessarily in meat firmness. In fact the addition of KCl may interfere with the function of carrageenan. In the presence of potassium the temperature at which carrageenan becomes soluble increases, which in turn restricts the swelling of carrageenan and reduces its ability to manage water. This, in turn leads to loss of weight in the processed meat during cooking, referred to as cookout. Please see Table 3.2. Discussions about carrageenan always include gelling characteristics due to their ability to differentiate between carrageenan types. For the most part, gelling characteristics are very important, especially from a quality assurance standpoint. However, comparison between carrageenans should stop short of discussing gel strength as an indicator of functionality in meat applications. In a study designed to investigate the gelling mechanism of a simulated protein solution similar to the aqueous environment of turkey breasts, Bater et al. (1992) found that ␬-carrageenan swelling was initiated at higher temperatures as the salt level increased. The authors found that at 0% salt, ␬-carrageenan began swelling at 28◦ C while at 4.4% salt, swelling didn’t begin until 67◦ C. Proteins began gelling at 52◦ C. Bater et al. (1992) concluded that an increase in salt concentration could cause an increase in swelling temperature and a decrease in ␬-carrageenan in meat products. At that

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Table 3.2. Addition of potassium chloride and effect on carrageenan functionality (Lamkey 2006). Added KCl Treatment (% of F.P.)∗ Cookout (%) Comments 1

0.00

0.2

2 3

0.16 0.32

0.7 2.3

4

0.64

8.5

5

1.28

11.6

6

2.55

10.6

∗

Excellent protein adhesion to cooking film Acceptable. Minimal protein adhesion Unacceptable. Gelled cookout on meat surface Unacceptable. Excessive soft gel cooked out Cookout was watery. Carrageenan did not swell Same as treatment#5

Finished product weight

point in time, the authors believed that carrageenan functionality in meat requires that the carrageenan go into solution. Prahbu and Sebranek (1997) found that carrageenan particles were dispersed throughout the product without evidence of gel formation. The authors’ hypothesis was that protein gels before carrageenan becomes fully soluble and therefore gets trapped within the protein gel structure. Prahbu and Sebranek (1997) also observed that starch and carrageenan were found in localized regions separated from each other. From these data it is highly unlikely that the synergism known to exist in water gels is manifested within the meat product. Carrageenan improves water retention, consistency, sliceability, and texture of poultry products with high levels of added brine (Trudso 1985). In regions of the world where 10 and 15% starch is added to economical hams, carrageenan is added at quantities of 0.5–0.8% to improve syneresis control and sliceability. On a global basis, cured hams are commonly formulated with carrageenan. Mills (1995) showed that 1.5% in a 38% added ingredient (AI) cured pork ham exhibited the highest cook yield for cook-in-bag products. The closest ingredient to carrageenan for this characteristic was sodium caseinate, which had a cook yield of 8% below that of carrageenan. The U.S. Department of Agriculture (USDA) does allow up to 1.5% carrageenan in cured pork products but it should be noted that this level of use is often too much for that level of AIs.

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Figure 3.1. (a) Micrograph of carrageenan in cooked meat; (b) fully hydrated carrageenan in water.

The functionality of carrageenan comes from its ability to swell and absorb water (Figure 3.1). During the heating stage, carrageenans swell and absorb the water entrapping it through the heating and storage phase. This allows for an increase in cook yield and a reduction in purge (syneresis). Poor quality raw materials will have a detrimental effect on product quality. One of the more common conditions processors face is pale, soft, and exudative (PSE) raw material. This condition is most commonly found in pork and turkey. As the name implies, the characteristics of PSE raw materials include a pale appearance, soft texture, and loss of moisture. A rapid pH decline at high temperatures during harvest is considered the primary cause of this due to a reduction in functionality of the proteins. In an effort to find an ingredient that will reverse this challenge, Motzer et al. (1998) looked at starch, ␬-carrageenan, and isolated soy protein in the manufacture of hams with increasing levels of PSE. Results indicated that k-carrageenan gave the highest chill yield when used in a 100% PSE product. Use level of carrageenan will vary depending on quality of carrageenan, level of standardization, and extension level of product being made. For all carrageenans, the characteristic being measured will increase for each unit increase in carrageenan to an optimum use level. Beyond that optimum level, adding more carrageenan does not give

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Cook yield (%)

96 94 92 90 88 86 84

0

0.2 0.4 Carrageenan concetration

0.6

Figure 3.2. Cook yield as affected by carrageenan concentration.

better results. That optimum level is unique for most processors, dependent on the product, raw materials, and processing condition. However, everything being equal, a rule of thumb for optimum carrageenan usage for cook yield, 0.1% carrageenan should be added for each 10% added brine (Lamkey 2006). Firmness requirements and purge control may need higher levels. The data in Figure 3.2 below depicts cook yield versus carrageenan concentration for turkey breast products that have been extended 50%. Optimum use for this application appears to be in the area of 0.5%. Although an interaction between milk proteins and carrageenan can be demonstrated, there is more of a symbiotic relationship with meat proteins. Meat proteins surround the carrageenan particle and act as an elastic netting to aid in the retention of water. In the event that the elastic netting is compromised, such as low quality raw materials or PSE, the retention of moisture will be reduced. Carrageenan does improve sliceabilty of meat products, especially for products destined for high-speed slicers. Firmness, however, is based more on the level of water added to the meat product. Figure 3.3 indicates the effect of added moisture on the firmness of turkey products. As the level of moisture increases, the firmness of the product decreases. With the addition of carrageenan, a trend exists where the carrageenan shows a different result at moisture to protein (M:P) ratios below 5.5 compared to those above 5.5. Figure 3.4 shows the effect on yield of using carrageenan versus a control without carrageenan. Figure 3.5

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Compression hardness

10000 9000 8000 7000 6000 5000 4000 3000 2000

4.00

4.50

5.00 5.50 6.00 Moisture to protein ratio Control

0.2

0.4

6.50

0.6

Figure 3.3. Hardness as affected by moisture protein ratio at four carrageenan concentrations.

shows the beneficial effect of carrageenan on water holding capacity in a warming tray over an extended period. Konjac Konjac is a hydrocolloid that is extracted from a tuber from the Asia Pacific region. The unique characteristic that sets konjac apart from other hydrocolloids is its ability to form heat stable gels. Konjac is able to achieve this characteristic through deacetylation, which is initiated 110.00 105.00

Yields (%)

100.00 95.00 90.00 85.00 80.00 75.00 70.00 Control

Carrageenan Treatments

Figure 3.4. Process yields as affected by carrageenan.

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Control vs. carrageenan

% Expressible moisuture

70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00

0

0.5

1 Warming Tray (Hrs) control

1.5

2

C

Figure 3.5. Moisture retention as affected by carrageenan.

by creating an environment that has a high pH. The higher the pH, the faster the reaction takes place. Unfortunately, in meat processing, proteins will be less functional at this pH and therefore the reaction must take place outside the system, creating an additional step. Synergies There are notable synergies between many hydrocolloids. Most notably, konjac/carrageenan, konjac/starch, carrageenan/starch, and konjac/ xanthan are a few of the synergies known. Synergism is defined as a measurable characteristic that shows a greater function in the presence of two or more ingredients that cannot be explained by a simple additive effect. For synergism to take an effect, the hydrocolloids have to be soluble and in intimate contact. In meat applications, heat soluble hydrocolloids show evidence of not being completely in solution. In addition, the protein matrix surrounding the hydrocolloid limits its movement and interaction with other ingredients in the product. Synergism among hydrocolloids is easily demonstrated in water gel systems, but may not manifest themselves in a meat application. Turkey Breast In the United States, turkey breast is the most common application for carrageenan. Products made with turkey breast can be whole muscle

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Table 3.3. Typical formulations for turkey breast.

Ingredients Water (<5◦ C) Salt (NaCl) Sodium tripolyphosphate Dextrose ␬-type carrageenan (Amount in finished product)

20% Brine Addition

35% Brine Injection

50% Brine Injection

80.5% 9.0% 3.0%

87.0% 5.8% 1.9%

89.2% 4.5% 1.5%

6.0% 1.5% (0.25%)

3.8% 1.5% (0.4%)

3.0% 1.8% (0.6%)

or ground and formed. The most common mistake made by turkey processors is using too much carrageenan for the application. This not only increases costs but can also result in detrimental effects referred to as “stretch marks” or “tiger striping.” This is a condition where the gel is visible between the muscle fibers. Please see Table 3.3 for recommended formulations for turkey breast.

Ham On a global basis, carrageenan is most often used in ham applications, although poultry applications are on the rise. In the United States, binders are approved for use in any cured pork product that is labeled as “Natural Juices”, “Water Added”, and “X% AIs.” It is common among cured pork processors as it is with turkey processors to use too much carrageenan. This gives a glassy appearance and promotes the appearance of “stretch marks” or “tiger stripes.” It becomes more difficult with ham processors as more fibrous muscle tends to increase the appearance of carrageenan between the fibers. Please see Table 3.4 for recommended ham formulations.

Roast Beef Using carrageenan in beef, and particularly roast beef, is a relatively new application that is less frequently seen in the U.S. market due to regulatory requirements. If used as an ingredient in roast beef, or any

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80% Pump

Ingredients

% in Brine

% in Brine

Water Salt Dextrose ␬-type carrageenan (Amount in finished product) Sodium tripolyphosphate Cure salt Sodium erythorbate

86.02 6.35 4.19 1.40 (0.55%)

89.14 4.58 3.03 1.62 (0.80%)

1.27 0.63 0.14

1.01 0.51 0.11

product with a standard of identity, a declaration on the name panel is required. Using carrageenan in roast beef applications has proven useful. The data suggest that a slight increase in cook yield can be obtained with the addition of carrageenan. In more firm muscles, however, cook yields are not higher. Carrageenan can increase the retention of moisture during extended heating times or when the product is held at high temperatures for long periods of time, such as in foodservice applications. Seafood The most common use for carrageenan is in imitation seafood products such as crab leg and shrimp analogues. These products use surimi as the raw material. Surimi is the name given to purified protein obtained from fish, specifically pollack, although other types of fish are used as well. Carrageenan is added to surimi applications to improve firmness, elasticity, and reduce costs. ␬-carrageenans are preferred when firm textures are desired. ␫-carrageenans give more elastic textures. In a study by Llanto et al. (1989), penetration and compression forces were highest with ␫-carrageenan, followed by lambda and lowest with kappa. Syneresis after three freeze/thaw cycles was least with ␫-carrageenan. ␫-carrageenan appears to be a viable carrageenan for surimi and surimi-based analogs when elasticity and freeze/thaw stability are top priority.

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There is some indication that konjac/carrageenan blends are useful also for surimi applications. Konjac does give the analog a more elastic texture while ␬-carrageenan adds to the firmness. The combination gives a texture that is firm but elastic.

Alginate Increasing the value of lesser-utilized muscles of the food animal has been the target of many published reports. These muscles are underutilized due to low palatability, usually originating from the hind leg or shoulder area. Removing the connective tissue, tenderizing, and formulating to a more desired product instinctively suggests that the product is improved. However, to get to this point usually requires comminution of the muscle and then reforming to a shape that is easily recognized and handled. Early reports on restructuring meat products promote the use of salt and/or phosphate to aid in the extraction of proteins. One of the downsides to the use of this process is that the product must be frozen in the raw state in order to retain the integrity of the muscle. During cooking, the extracted proteins act as glue and bind the pieces of meat together. Sodium alginate was investigated to determine its acceptability for binding pieces of meat during the raw state. This process had the advantage of not needing the inclusion of salt or phosphate for protein extraction. The gel formed by this process is all that was needed to hold the pieces of meat together. Alginate is an extract from brown seaweed and has the unique characteristic of forming a gel in the presence of a divalent cation. The cation most often used for this process is calcium. Borium, for example, will give a stronger gel but due to its toxicity, it is not used for food applications. There are a large number of publications describing the gelling mechanism for alginate. The basic premise is that there are G-blocks and Mblocks that comprise the backbone of the alginate molecule. G-blocks are responsible for the gelling of alginates while M-blocks are responsible for viscosity. Within the G-block structure, there are binding sites for calcium which when activated cause a gel to form. As calcium concentration increases, there is an increase in the strength of the alginate gel until

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all sites are loaded. Formulators need to recognize that increases in calcium level can also result in an increase is syneresis or purge. The process was patented by researchers at Colorado State University. The process uses sodium alginate, calcium carbonate, and gluconodelta-lactone (GDL). Sodium alginate will be hydrated by the moisture in the meat. The solubility of calcium carbonate is increased in an acidic environment. Therefore, GDL decreases pH and solubilizes calcium carbonate making the calcium available for gelling the alginate. Once the gel has set, the product is sliced into steaks or chops. Since the calcium alginate gel is heat stable, the product will not fall apart during cooking. Although alginate is an ingredient easily added to a meat system, being a batch-type process reduces the acceptance among larger processors. The timing of gel formation during this process is the most critical when adapting the process to current systems. There are three ways in which the gelling process can be controlled. Hydration of the alginate gel, solubility of the calcium source, and the concentration and type of a sequestrant, such as phosphate, are the three most common methods to control gelling strength and timing. Alginate is a cold soluble hydrocolloid. As indicated earlier, adding alginate directly to the meat source will allow the alginate to hydrate. However, to decrease the amount of time required to hydrate the alginate, blend the alginate with water prior to adding in the protein source. One of the more common methods by which gel set time can be manipulated is by selecting the calcium source on the basis of solubility. Calcium carbonate is the least soluble calcium source but can be increased with a decrease in pH. Calcium sulfate or calcium lactate has medium solubility. Calcium chloride is the most soluble of the available calcium sources and will create the fastest alginate gel formation.

References Bater B., Descamps O., and Maurer A.J. 1992. Kappa-carrageenan effects on the gelation properties of simulated oven-roasted turkey breast juice. J Food Sci, 57:845–847, 868. Lamkey J.W. 2006. Unpublished Data. Lee C.M. 2002. Role of hydrodynamically active biopolymeric ingredients in texture modification and physical stabilization of gel-based composite foods. J Food Sci, 67:902–908.

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Llanto M.G., Bullens C.W., and Modliszewski J.J. 1989. In: Effects of Carrageenan on Gelling Potential of Surimi Prepared from Atlantic Pollack. Paper presented at the Seafood Biotechnology Workshop, St. Johns: Newfoundland, Canada. Mills E.W. 1995. Nonmeat binders for use in cook-in-bag and smoked ham. J Muscle Foods, 6:23–35. Motzer E.A., Carpenter J.A., Reynolds A.E., and Lyon C.E. 1998. Quality of restructured hams manufactured with PSE pork as affected by water binders. J Food Sci, 63:1007–1011. Prahbu G.A. and Sebranek J.G. 1997. Quality characteristics of ham formulated with modified corn starch and kappa-carrageenan. J Food Sci, 62:198–202. Trudso J.E. 1985. Increasing yields with carrageenan. Meat Proc, 24:37–39.

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Chapter 4 Hydrocolloids in Bakery Products William Santa Cruz

More and more so the beneficial properties of hydrocolloids, which are commonly referred to as gums, are being realized to the benefit of processed foods. The thickening, suspending, gelling, and emulsifying properties enhance, stabilize, and maintain the integrity of almost all processed food products. Or, stated in another way, gums are in, will be in, or should be in almost all processed foods. And although gum use is not limited to the processed food industry (more and more gums are finding their way into the kitchens of restaurants, as well as into the kitchens of a number of average American homes.), within this industry gums are looked upon to address such issues as shelf-life extension, fat replacement, oil migration reduction, reductions of costly ingredient consumption, freeze-thaw stability, extruded product integrity, as well as enabling for calorie-reduced dietary products without sacrificing the full-bodied texture and mouthfeel. Additionally, by providing body as well as moisture control, gums can enable consumption reductions of trans-fatty acids (hydrogenated and partially hydrogenated oils). And while gums continue to find application within almost all processed foods within the food industry, the focus of this chapter is the applications of gums within a few baked and related products. All gums present their own unique attributes or properties. When gums are used in combinations (blends), the results are at least complimentary, but more commonly demonstrate synergism—the Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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demonstrated results are usually superior to those anticipated when taking into account the gums’ respective characteristics. And at times the results produced by gum blends are uniquely different from those of the individual gums, as is the case of the gelling action that occurs by combining xanthan gum with locust bean gum. It is this enhancement of properties, and/or the development of new properties, that in many cases provide the argument for a blended stabilizer in place of a straight gum. Basically, the idea of custom blending allows for the enhanced targeting toward specific properties, or outcomes. And although the costs of blends tend to be a bit higher than those of straight gums, the increase in cost may be slightly offset by the fact that blends tend to achieve a desired outcome at a lower usage level. Therefore, in a nutshell, (1) blends tend to achieve desired results at lower usage levels; and (2) tailored blends tend to provide for a more precise outcome. For example, xanthan gum is probably the most widely used gum today. With its versatility (second possibly only to that of konjac gum), xanthan gum’s popularity is readily understood. Simply stated, xanthan gum is an excellent product, but is xanthan gum the product of choice for every application? Or, stated in another way, is it reasonable to expect that any one-gum product will be the gum of choice for every application? In reality, the product’s desired outcome should dictate the gum(s) of choice. Therefore, within the scope of gums in baked products, of the many fine gums available today, for our purposes the gums that are presented throughout the chapter—either as a stand-alone or in blends—are: CMC gum (sodium carboxymethylcellulose)—An excellent stand-alone thickening agent, demonstrates the highest clarity of the gums, in general, with a thickening ability that classifies as a pseudogel. The only drawback associated with CMC gum is that it is considered to be a modified gum, as opposed to being an all-natural product. Fenugreek gum—A quick hydrating thickening agent (also well-suited for sport drink applications) possessing emulsifying properties like gum tragacanth. Guar gum—A relatively quick hydrating thickening agent, available in low, medium, and high viscosity-producing versions with very competitive pricing. Konjac gum—One of the most versatile of the hydrocolloids, is a thickening agent (probably the highest viscosity-producing gum), a gelling agent with the ability to produce thermal reversible as well as

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nonthermal reversible gels, and is a pseudoemulsifier as well as a filming agent. Xanthan gum—An excellent thickening agent and pseudoemulsifier with stability within a wide range of pH environments, and is produced in such quantities internationally as to make it a readily accessible product. Its only possible drawback, because xanthan gum is the product of a fermentation process, is that not all consumers are able to recognize it as an all-natural product. It is important to note that while the same gum combinations will be presented for the following different applications, the gum ratios within the blends typically will vary. It is important not only to have the appropriate overall gum level within a formulation, but in the case of blends to have the appropriate ratio within the blend.

Gums in Bread With the following “basic bread formulation,” the gums presented are those that historically have demonstrated well within bread products. In the photo below, clockwise from top left are breads containing: control (no gum), a konjac gum/fenugreek gum∗ blend, a CMC gum/fenugreek gum∗ blend, and xanthan gum∗ (straight). Under identical baking conditions, the breads containing the gums retained a slightly higher postbaked weight percentage—92.4, 92.3, and 91.8%, respectively, versus the control at 90.9%. Regarding the physical dimensions of the finished products, although the differences were minimal, the texture and mouthfeel demonstrated by the konjac gum/fenugreek gum∗ blend seemed superior with a moist, somewhat chewy mouthfeel, followed by that of the CMC gum/fenugreek gum∗ blend, which was moist but not as chewy, followed by the xanthan gum∗ (straight), which was moist but even less chewy. Upon thawing following a 3-week freeze period, the bread containing the konjac gum/fenugreek gum∗ blend continued to demonstrate a superior moist mouthfeel, with minimal rupturing occurring along the crust-edges during slicing; similar rupturing along the crust-edges occurred during slicing with the other two gum-containing breads, but slightly diminished mouth feels were demonstrated respectively with the CMC gum/fenugreek gum∗ containing bread, followed similarly by the bread containing xanthan gum∗ (straight). The control (no gum) bread, upon thawing following the 3-week freeze

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period, tore readily throughout during slicing and demonstrated a dryer mouthfeel.

Basic Bread Formulation Flour, all-purpose Water Oil, canola Sugar, granulated Salt Yeast, active dry Yeast, active dry Baking powder Gum∗

% by Weight 58.01 36.36 1.66 1.55 1.01 0.77 0.31 0.17 0.16 100%

∗

Gums that demonstrated well with this formulation at the 0.16% overall usage level were blends of konjac gum/fenugreek gum with a 48:52 ratio, CMC/fenugreek gum with a 36:64 ratio and straight xanthan gum.

Preparation 1. Thoroughly mix flour, salt, yeast (0.31%), baking powder, and gum. 2. Dissolve the sugar into the water, heat to 140◦ F, then mix in the remaining yeast (0.77%) and allow mixture to rest for 5 minutes. 3. Gradually, blend in the wet mix into the dry mix and process until a rough ball forms.

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4. With minimal agitation, coat oil onto the dough ball. 5. Allow dough to rest for 5 minutes, place into a covered container and refrigerate until dough doubles in size (minimum 2 hours—up to 24 hours.) 6. Preheat to 400◦ F. 7. Punch dough down, shape, and heat for 30–35 minutes, until interior heats to 190◦ F. Gums in Cake Within the “basic cake formulation” that follows, gums that tend to perform favorably within cakes are konjac gum/fenugreek gum∗ blends, CMC gum/guar gum∗ blends, and xanthan gum∗ (straight). When compared with the control (no gum), which retained 91.0% of its original weight, the above listed gums respectively retained 91.4, 91.4, and 91.3%. The texture and mouthfeel of the gum-containing cakes were: for that of the konjac gum/fenugreek gum∗ blend, smooth, moist, and fluffy; for that of the CMC gum/guar gum∗ blend, smooth but slightly dry; and for that of the xanthan gum∗ (straight), moist but with a dense, or thick, mouthfeel. Following a 3-week freeze period, all 3 of the gum-containing cakes demonstrated similarly superior textures and mouthfeels but the control (no gum) cake tended to demonstrate a dry mouthfeel and a crumbly texture. Pictured below is a slice of the bread containing the konjac gum/fenugreek gum∗ blend.

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Basic White Cake Formulation Cake flour Sugar, Baker’s Milk, 2% Egg, whole Butter, unsalted Baking powder Vanilla Salt Gum∗

% by Weight 30.62 22.45 17.21 16.06 11.43 1.02 0.71 0.35 0.15 100

∗ Gums that demonstrated well with this formulation at the 0.15% overall usage level were blends of konjac gum/fenugreek gum with a 30:70 ratio, CMC/guar gum with a 30:70 ratio, and straight guar gum.

Preparation Preheat oven to 350◦ F. Dry blend flour, sugar, baking powder, salt, and gum. Incorporate softened butter into dry blend. Lightly combine egg, milk, and vanilla into a wet mix. Combine the wet mix into the dry mix and agitate (low speed) for 30 seconds. 6. Pour batter into lightly greased cake pans and bake for 25–35 minutes until the center of the cake heats to 221◦ F. 1. 2. 3. 4. 5.

Gums in Flour Tortillas As with foods in general, the characteristics regarding the quality of tortillas are directly related to the ingredients used. Common tortilla formulations include lard, shortening, or vegetable oil. Their purposes, in addition to imparting a full-bodied texture, mouthfeel, and flexibility, are to reduce the process of drying out. Regarding products for retail, moisture loss greatly impacts a product’s shelf life. Therefore, the primary role for gums to play within tortilla applications would be moisture control. Regarding typical tortilla formulations, some gums that typically provide positive moisture control are blends of CMC gum/fenugreek

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gum∗ , konjac gum/fenugreek gum∗ blends, and straight konjac gum∗ . After incorporating (individually) each of these three gums into the following basic tortilla formulation, all three gums provided excellent short-term results, as expected. As with the control tortilla, the three gum containing versions demonstrated a smooth, full-bodied mouthfeel and excellent flexibility. The difference became readily apparent as time elapsed. The rolled tortilla pictured below contains straight konjac gum. The tortilla was photographed upon thawing following a 2-week freeze period. While the other gum-containing tortillas fractured along the fold at this point (as did the control), the konjac gum-containing tortilla maintained its structural integrity with only slight indications of potential ruptures—a whitened discoloration—visible near the topleft edge as well as near the top-center. Although the overall splotchy coloration would seem to indicate moisture migration, the tortilla was able to maintain the fold unruptured.

Basic Tortilla Formulation Flour, all-purpose Water Oil (canola) Baking powder Salt Gum∗ ∗

% by Weight 55.99 29.36 13.69 0.43 0.40 0.13 100

Gums that demonstrated well with this formulation at the 0.13% overall usage level were a blend of CMC gum/fenugreek gum∗ blend with a 36:64 ratio, a konjac gum/fenugreek gum∗ blend with a 48:52 ratio, and straight konjac gum∗ .

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Preparation 1. Dry-blend together the flour, baking powder, salt, and gum. 2. Mix in the oil in thoroughly with the dry blend mixture. 3. Heat water to 140◦ F, and then slowly incorporate the water into the oil and dry-blend mixture until the dough forms into a soft elastic ball. 4. Knead until smooth. 5. Divide dough into separate 90-gram balls. 6. Cover and allow dough to rest for 15 minutes. 7. Preheat griddle to medium heat (250–275◦ F). 8. Roll dough balls out to 8–9 inch diameter tortillas. 9. Place lace tortilla on the heated griddle for approximately 30 seconds/side.

Gums in Reduced Oil Flour Tortillas With low calorie, oil-reduced tortilla formulations, in addition with moisture control/shelf-life concerns, gums will also greatly impact the texture and mouthfeel of the product. As in the case of the abovementioned formulation, a reduction of the oil percentage—from 13.69 to roughly 3%—would necessitate an increase in the gum levels into the 0.5–1.0% range. Additionally, within such an oil-reduced formulation, you would also expect adjustments regarding blend ratios. For example, with a konjac gum/fenugreek gum blend, you might expect to install a higher konjac gum percentage. Also, guar gum and xanthan gum, either as stand alone or in blends, would be solid contenders for consideration.

Gums in Egg Pasta Although egg pasta is traditionally made with durum semolina, for our purposes we have utilized all-purpose flour. Due to the minimal moisture availability within the following formulation, the gums—konjac gum (straight), konjac gum/fenugreek gum (blend), and fenugreek gum/guar gum (blend)—are utilized at the 1% level of the overall formula weight. Considering konjac gum’s super high viscosity potential, combined with

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a decent hydration rate, konjac gum would be a natural within pasta applications. Regarding the formulation’s low moisture level combined with the high percentage of egg (protein, emulsifier), the rapid hydration characteristic of fenugreek gum should prove effective in this as well as similar formulations. And guar gum—with a relatively high viscosity potential, a decent hydration rate and at very competitive pricing—is always a wise choice. The gum-containing products demonstrated smoother textures versus the nongum-containing control immediately upon being cooked. After freezing for 2 weeks, thawing, and recooking the differences between the gum and nongum products was more pronounced. In the photo below, top-to-bottom, are the control (no gum), followed by the pastas (a fettuccine and a spaghetti) that contain the konjac gum, the konjac gum/fenugreek gum blend, and the fenugreek gum/guar gum blend. At this point, the control tore easily. The konjac gum pasta demonstrated elasticity with a silky smooth texture, a similar texture but less elasticity was demonstrated by the konjac gum/fenugreek gum containing pasta. The fenugreek gum/guar gum blend presented a full-bodied but densefeeling texture. Also effective pasta stabilizing gums are the carrageenan (kappa and iota) and konjac gum/carrageenan gum blends, as well as konjac gum/xanthan gum blends.

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Basic Egg Pasta Formulation Flour, durum semolina Egg, whole Gum∗ Oil, olive Salt

% by Weight 70.01 28.04 1.00 0.69 0.26 100

∗

Gums that demonstrated well with this formulation at the 1.00% overall usage level were blends of konjac gum/fenugreek gum at a 50:50 ratio, fenugreek gum/guar gum at a 50:50 ratio, and straight konjac gum.

Preparation 1. Dry blend the flour, salt, and gum. 2. Thoroughly mix in the egg with the dry blend. 3. Thoroughly mix in the oil into the dough and knead until the dough attains a smooth and silky texture. 4. Place in covered container and refrigerate for 1 hour. 5. Roll out the dough and shape with a pasta machine. 6. Bring a sufficient container of water to a boil. 7. Cook the pasta in the boiling water for 1–2 minutes, until the pasta floats to the surface of the boiling water.

Gums in Pancakes The following straight gums were tested within the “basic pancake formulation” below: CMC gum (medium viscosity), fenugreek gum, konjac gum, and xanthan gum. Due to the relatively quick hydrating action of the gums, the milk was incorporated in with the other ingredients once the griddle was at the appropriate cooking temperature. To reduce the gluten action and to control gum hydration, minimum agitation was applied while incorporating in the milk. Even so, the CMC gum, fenugreek gum, and konjac gum containing batters thickened quickly

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during agitation. The xanthan gum containing ingredients demonstrated a uniform, smooth transition into a batter. Also, the xanthan gum containing batter maintained a more uniform shape and consistency on the griddle while cooking into thick, fluffy pancakes. The pancakes of the other batters tended to be lumpier, less fluffy, and less uniform in shape. The CMC gum-containing batter produced pancakes close in quality to that of the xanthan gum-containing batter, which demonstrated an appearance reminiscent of grocery store purchased frozen waffles. Upon thawing and reheating following a 2-week freeze period, the xanthan gum-containing pancake maintained a higher degree of firmness and fluffiness during slicing, as well as in mouthfeel. Again, the CMC gum-containing pancake was firm but not as fluffy, followed by the fenugreek gum-containing pancake. The nongum containing control was somewhat fragile to the touch and demonstrated a dry mouthfeel. Pictured below are, first, the pancake with xanthan gum, and second, the control.

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Basic Pancake Formulation Milk, 2% Flour, all-purpose Egg, whole Oil, canola Sugar, granulated Baking powder Salt Gum∗ ∗

% by Weight 47.97 28.43 11.44 6.61 3.09 1.62 0.69 0.15 100

Gums that demonstrated well with this formulation at the 0.15% overall usage level were straight gum products (no blends) of: CMC gum (medium viscosity), fenugreek gum, konjac gum, and xanthan gum.

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Preparation Preheat griddle to 350◦ F. Dry-blend the flour, sugar, baking powder, salt, and gum. Mix oil into dry blend. Mix egg into oil/dry blend mixture. Whisk milk into mixture until large there are no large lumps. Lightly oil griddle. Ladle 3 ounces (90 grams) of batter onto the griddle and heat for 45–60 seconds, until bubbles set on the pancake edges. 8. Flip and heat second side for 30–40 seconds.

1. 2. 3. 4. 5. 6. 7.

Gums in Fried Cornbread Muffins The following fried cornbread muffin formulation involves a baking stage, followed by a frying stage. With this approach, gums would be looked upon to minimize moisture loss during the baking stage and to minimize the oil absorption during the frying stage. Blends that typically demonstrate well within both applications are a xanthan gum/guar gum blend and a konjac gum/fenugreek gum blend. With this formulation, the muffins were baked with a starting batter weight of 65 grams. The postbaked weights were 87.07% in the nongum control, 87.81% with the xanthan gum/guar gum blend, and 88.12% with the konjac gum/fenugreek gum blend. Upon being fried, the average amount of oil absorption was 12.22% for the nongum control muffin, 9.06% with the xanthan gum/guar gum blend, and 9.97% with the konjac gum/fenugreek gum blend. Therefore, while the xanthan gum/guar gum blend retained a slightly lower overall weight after baking at 87.81% compared with the konjac gum/fenugreek gum blend at 88.12%, the former absorbed a lower percentage weight of oil than did the latter—9.06% versus 9.97%. Ideally, after frying, a browned crust measuring close to 1/16 in thickness would encase the muffin and internally, the oil should not penetrate much more than 1/4 . Pictured below, following a 2-week freeze period, the control sits at the top, the xanthan gum/guar gumcontaining muffin sits to the bottom left, with the konjac gum/fenugreek gum containing muffin on the bottom right.

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1/16 fried shell cornbread muffins

Basic Fried Cornbread Formulation Flour, all-purpose Cornmeal (white or yellow) Milk, 2% Oil (canola) Egg, whole Sugar, granulated Baking powder Salt Gum∗ Baking Powder

% by Weight 30.01 22.45 20.25 9.77 9.44 5.86 1.20 0.55 0.25 0.22 100

Oil cooking spray (optional). ∗ Gums that demonstrated well with this formulation at the 0.25% overall usage level were the 2 following blends: guar gum/xanthan gum at a 50:50 ratio and konjac gum/fenugreek gum at a 30:70 ratio.

Preparation 1. 2. 3. 4. 5. 6.

Preheat oven to 400◦ F. Mix the dry ingredients thoroughly. Thoroughly mix the oil into the mix of dry ingredients. Thoroughly mix in the eggs. Thoroughly mix in the milk. (Avoid over mixing) Cooking spray lightly the muffin sheet (optional).

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Measure out 65 g of the prepared mix into the muffin sheet cups. Bake for 15 minutes. Allow to cool for 30 minutes. Preheat frying oil to 265◦ F. Fry for 15 seconds.

Optional Nonbaked Fried Cornbread With straight fried cornbread, the same formulation and gum blends were used as with the baked/fried cornbread muffin—the guar gum/xanthan gum blend and the konjac gum/fenugreek gum blend. Again, a 1/16 fried crust should encase the cornbread after frying. With this formulation, the results were too close to call. After frying, the guar gum/xanthan gum containing cornbread averaged a loss of slightly less than 1/2 g in weight, from 65 g to just above 64.5 g; the konjac gum/fenugreek gum containing cornbread averaged a before and after frying weight of approximately 65 g. Other than the crust, no internal oil-absorption zone was evident with either. Do these results indicate that the guar gum/xanthan gum containing cornbread lost a little more in moisture weight than oil absorbed, while the konjac gum/fenugreek gum containing cornbread gained as much in oil as was lost in moisture? Pictured below is konjac gum/fenugreek gum containing cornbread following a 2-week freeze period, whereby the cornbreads with both gums maintained a sturdy body and a chewy mouthfeel upon open-air thawing and microwave heating. 1/16 fried shell cornbread muffins

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Preparation Upon completing steps 1–5 of the basic fried cornbread formulation (above): 6. Preheat frying oil to 265◦ F 7. Roll 65 g of dough into a ball, then into 5 bread sticks. 8. Fry for 2 minutes. ∗

Gums that demonstrated well with this formulation at the 0.25% overall usage level were the following 2 blends: guar gum/xanthan gum at a 50:50 ratio and konjac gum/fenugreek gum with a 30:70 ratio.

Gums in Pizza Dough Unlike most bread, pizza dough is exposed to a baking process whereby a sauce is placed atop the dough and undergoes heating while the dough is baked. Although a certain amount of moisture will be absorbed from the sauce into the bread, gums within the dough will reduce the amount of moisture that will absorb past the surface area of the bread, lessening the sogginess of the bread, over time. Gums that demonstrate well within this application are the typical thickening agents xanthan gum, guar gum, CMC, and konjac gum. Additionally, xanthan gum/guar gum blends and xanthan gum/guar gum/alginate gum blends have proven to be effective stabilizers for this application, especially within grocery store purchased frozen pizza products. Within this application, the action of the gums will be to minimize the effects of moisture migration during the thawing and subsequent heating stage. Gums at the 0.10–0.15% levels demonstrate well within this application. Gum within the tomato-based sauce will further prevent moisture migration into the bread.

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Chapter 5 Hydrocolloids in Bakery Fillings Marceliano B. Nieto and Maureen Akins

Introduction Bakery fillings include a wide variety of formulations that are as diverse as the bakery products they accompany. Fillings can either be fruit-based, cream-based, fat-based (such as shortening), or egg-based. Formulations can vary in the levels of acidity (pH), water activity (aw ), and amount of solids they contain. Processing techniques may also vary widely in this category of foods. These basic categories of fillings may need to be emulsified, aerated, retorted, or simply thickened until the desired mouthfeel characteristics are achieved. Fillings can be either processed without heat or cooked prior to use in the pastry. The extent by which each filling is processed, and in turn stabilized, is strictly determined by the needs of the formulator preparing the fillings. Production can occur in a kitchen-type setting, without the need for sophisticated equipment, or in case of commercial operations, prepared with more extensive continuous flow machinery. A continuous process can include a cook tank, high shear mixer, pumping system, filler, and other value-added devices that can aerate, inject, or spread the filling onto the pastry. There is an ever-increasing segment of the industry that is dedicated solely to producing and supplying fillings in bulk packages to food companies, bakeries, and restaurants, or in cans for retail distribution and home use. Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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Shelf-life requirements for bakery fillings extend across all areas of storage. Fillings may be frozen, refrigerated, or canned to increase shelf stability. Alternately, some fillings are created with short-term use in mind. Many shelf-stable filled pastries and snack bars are individually wrapped for distribution without refrigeration, and baked pies are either distributed without refrigeration in grocery stores, or frozen, thawed and rebaked by the consumer. Canned fruit fillings are sold in retail distribution for home use, or packaged in larger containers for institutional use. Still there are many home bakers who choose to prepare the fillings from scratch so that they can serve the pie fresh from the oven. Each of these scenarios creates unique challenges and increases the complexity when stabilizing bakery fillings. Specifically, controlling viscosity, aw , and pH become critical points in providing effective stabilization. One thing is for sure, the use of a stabilizer, in the form of flour, starch, and gums (or some combination), will provide consistency, machinability, stability, and acceptable quality attributes for whatever type of filling you are trying to create. After considering ingredient, processing, and storage variables, the best stabilizing system for each group of products can be determined. A cookie or snack bar filling requires a firm consistency to resist melting and maintain shape, and must also have low aw to provide protection from microbial growth. Aerated cr`eme fillings require foam stability and structure to reduce shrinkage and collapse while in the pastry. Doughnut fillings (normally injected after the doughnut is fried) are usually kept for a very limited period of time. The appropriate consistency is necessary but the filling does not need to be excessively process tolerant or shelf stable. Like doughnuts, fruit pie fillings that are made and used fresh only require minimal thickening ability, but the same pie fillings that are baked, frozen, thawed, and rebaked require a much more substantial stabilizer capable of withstanding substantial processing and storage requirements. Also, it is important to remember that stabilizers should not mask or diminish the quality of the original ingredients, they are only meant to enhance the finished product. Proper balance of ingredients is necessary for the development of functionally sound bakery filling formulations. Several critical factors need to be identified before the best stabilizer system can be selected for your product. Conditions in the formulation such as pH, available

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water, and competing ingredients, such as sugar, affect hydrocolloid selection. Processing conditions relating to the amount of shear available, how much heat will be applied, whether or not the product will be frozen, or if the intended shelf life is short or extended will need to be addressed. Consumer end-use will also play a role in ingredient selection. Knowing these details will help to prevent lumping, incomplete activation, or loss in effectiveness of your hydrocolloid over time. Once all parameters have been identified, it is essential to select the appropriate hydrocolloid for each characteristic you desire. Thickening agents such as gums and starches require proper selection on the basis of their viscosity, gelling properties, rheology, stability, and cost. Purposeful use of gums can make formulation of fillings a successful endeavor.

Filling Types Fruit Fillings Apple and cherry are among the favorite fruits for use in freshly made pies sold in bakery sections of grocery stores; however, almost any fruit, such as peaches, apricots, blueberries, or strawberries, can be used effectively in pie fillings. In addition to flavor, processors have at their disposal several categories from which to select the best type of fruit for their type of filling. Fruit is available in fresh, dried, canned, frozen, or individually quick frozen (IQF) forms. Fully prepared fillings are also a convenient option available to the baking industry. Dehydrated or dried fruits allow processors to maintain stocks for a greater length of time, while still providing unique flavor profiles to a formulation. Canned products allow for extended shelf stability of the finished product due, in part, to the heat treatment afforded by the fruit during processing. IQF-processed fruit provides a product that most closely approaches fresh; the freezing process takes place relatively quickly, minimizing fruit tissue damage by ice crystals. Frozen versions may come packaged as 100% fruit or as a sugar-added type, such as a 5 + 1 form (5 parts fruit and 1 part sugar) or 4 + 1. The added sugar helps prevent ice-crystal formation, decreasing damage to the fruit’s structure.

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Once the fruit source has been determined, it is combined with sugar (sucrose, glucose, high fructose corn syrup (HFCS), or corn syrups), stabilizer, and an acidulant to complete a basic fruit filling. Higher sugar levels reduce the amount of time required for the solids in the finished filling to reach equilibrium. The addition of sugar affects the specific gravity of the fruit pieces, which aids in dispersion by preventing floating or sinking. Additionally, sugar can help protect fruit texture by depressing the freezing point during a freezing cycle. Freezing point depression reduces ice-crystal formation and prevents the fruit structure from being damaged by ice-crystal growth. As a minor ingredient but major player, stabilizers will provide thickening, suspension, mouthfeel, heat stability, freeze/thaw stability, and maintain moisture in the fillings. Proper stabilization can improve texture and even provide cost savings when used correctly. Lastly, and importantly, an adjustment in pH of the filling through the use of an acidulant will protect against microbial growth. Depending on the processing of the filling, the choice of stabilizer will vary. When a fruit filling is canned, the stabilizer needs to thicken during the precooking step to suspend the fruit pieces before the cans are filled. This will prevent any inconsistencies from can to can due to settling. In addition, the stabilizer must be acid and heat stable due to the conditions of the formula and the high temperatures reached during retort processing. Additionally, rheological and textural attributes of the suitable gum and/or starch system must match the desired mouthfeel of the finished product. It doesn’t matter how stable a system is if the end consumer doesn’t like it. A fruit filling, by convention, needs to be thick, semiclear, or translucent and have a short texture. Viscosities of canned fruit filling, as shown in Table 5.1, can range from 7,500 cP to over 57,000 cP, indicating that varying levels of stabilization and thickening are needed. From a processing point of view, lower viscosity fillings are more prone to boil out and may also result in excessive moisture movement to the crust portion of the product. The pH of the filling can be below 3.0 and above 4.0 as shown in Table 5.1. When a filling is made by dry blending IQF fruits and stabilizer mix (containing sugar and acidulant), the stabilizing approach will be slightly different since the stabilizer is not predissolved in the water phase as in the case of a canned fruit filling. Water from the fruit needs to leach out and dissolve the stabilizer completely during the baking and cooling step. It is also very important that the sugar-stabilizer mix is

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Table 5.1. Processing and quality attributes of commercial bakery fillings.

Pastry

Moisture (%)

Water Activity (aw ) pH

A. Canned Pie Fillings Cherry pie 75 filling Apple pie filling 70.3

0.937

3.38

0.926

3.53

Peach pie filling

73.4

0.933

3.23

Strawberry pie filling Blueberry pie filling Lemon pie filling

75.8

0.936

3.34

73.3

0.925

2.98

62.3

0.932

3.61

No sugar cherry pie filling Cherry pie filling Apple pie filling

88.2

0.931

3.42

70.6

0.941

3.22

70.1

0.932

3.09

74.1

0.934

3.03

74.5

0.966

5.66

23.2

0.854

5.77

B. Ready to Eat Snack Cakes Cr`eme rolls 10.5 0.722

4.34

Blueberry pie filling Pumpkin pie mix Poppy seed pie filling

Reduced fat oatmeal pies Oatmeal pies Cr`eme filling Chocolate squares

13.3

0.688

6.05

12.2 22.4 16.4

0.688 0.785 0.755

6.16 4.81 4.34

Gums Modified food starch Modified food starch Modified food starch Modified food starch Modified food starch Agar Locust bean gum Modified food starch Modified food starch Modified food starch Modified food starch Modified food starch Modified food starch Modified food starch Modified food starch Carrageenan Cellulose gum Modified food starch

Viscosity (cP) Brix 24,100

28.0

7,440

26.4

17,400

25.0

32,500

24.6

38,900

30.4

81,400

37.3

14,400

13.5

23,800

31.3

57,400

30.2

26,600

28.0

32,000

25.1

—

—

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Table 5.1. Processing and quality attributes of commercial bakery fillings. (continued)

Pastry

Moisture (%)

Water Activity (aw ) pH

Chocolate squares Marshmallow Swiss rolls

13.8

0.718

4.02

15.6 16.1

0.717 0.733

6.20 5.25

Jelly filling

29.8

0.824

3.72

C. Ready to Eat Pies Apple pie 45.8

0.869

4.73

Lemon pie

31.5

0.777

3.30

Chocolate pie

17.4

0.768

5.25

Apple pie Coconut cr`eme pie Cherry pie

67.5 45.0

0.934 0.922

4.26 6.03

55.3

0.931

3.63

Apple pie

63.0

0.927

4.72

Lemon pie

53.3

0.932

3.49

Vanilla pudding pie Apple pie

52.2

0.925

6.02

30.7

0.809

3.87

Peach pie

52.3

0.910

3.84

Gums Modified food starch Gelatin Modified food starch Pectin Xanthan gum Pectin sodium alginate Agar Locust bean gum Sodium alginate Locust bean gum Arabic Cellulose gum Gellan gum Cellulose gum Gellan gum Cellulose gum Gellan gum Cellulose gum Gellan gum Cellulose gum Gellan gum Agar Locust bean gum Cellulose gum

Viscosity (cP) Brix

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Table 5.1. Processing and quality attributes of commercial bakery fillings. (continued)

Pastry

Moisture (%)

Water Activity (aw ) pH

Cherry pie

19.3

0.797

3.61

D. Frozen Pies and Desserts Eclairs 55.7 0.924 Cr`eme puffs 52.0 0.930

6.73 6.78

Key lime pie

28.8

0.890

4.43

Pecan pie

18.3

0.843

5.70

Apple pie

65.0

0.933

3.35

Blueberry pie

69.0

0.945

3.53

Peach cobbler

54.7

0.936

3.53

Apple dumplings Cheese cake

62.5

0.934

3.07

55.4

0.930

4.90

Cherry pie

69.5

0.937

3.23

E. Cookie Fillings Shortbread 19.3 cookies

0.682

3.63

Gums Gellan gum Agar Locust bean gum Carrageenan Cellulose gum Carrageenan Carbohydrate gum Xanthan gum Guar gum Modified food starch Modified food starch Modified food starch Modified food starch Modified food starch Carob bean gum Guar gum Carrageenan Xanthan gum Cellulose gum Modified food starch Cellulose gel Cellulose gum Propylene glycol alginate

Viscosity (cP) Brix

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Table 5.1. Processing and quality attributes of commercial bakery fillings. (continued)

Pastry Fudge mint cr`eme Shortening type filling Cr`eme filling Yogurt breakfast bars Strawberry cookie filling Fruit breakfast bars

Toaster pastries

Moisture (%)

Water Activity (aw ) pH

0.758

0.68

5.36

1.83

0.696

5.87

1.74 20.3

0.452 0.639

2.99 4.42

23.9

0.673

3.88

19.7

0.645

5.06

17.0

0.649

3.32

Gums

Viscosity (cP) Brix

Modified food starch Modified food starch Xanthan gum Cellulose gum Cellulose gel Carrageenan Guar Pectin Sodium alginate Modified cellulose Xanthan gum Cellulose gum Gelatin

uniformly blended with the fruit to prevent localized “goo” or hardened sugar-stabilizer regions in the finished pie. This is a common problem seen with fruit pies prepared in this manner. The sugar-stabilizer mixture should partially melt and stick to the thawing fruit for even coverage. Sugar–starch stabilizer systems are problems especially at high starch levels in the systems. The stabilizer stays dry and dusty during the first 30 minutes of thawing causing the stabilizer to stratify. In this situation, using a sugar-gum system will allow the water condensation around the fruit during thawing to partially melt the sugar-gum system and make the stabilizer stick more uniformly to the fruit. Additionally, the use of a hygroscopic gum such as polydextrose, in addition to gum thickeners, is an option for the processors to increase melting and adhesion of the system to the fruit.

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Fruit Filling Formulation Ingredient HFCS IQF fruit Sugar Water Modified food starch Pectin/guar combination Xanthan gum Sodium benzoate Citric acid Flavor/color

% 34.3 22.0 20.0 20.0 2.0 1.5 0.1 0.1 q.s. q.s.

q.s., quantity sufficient.

Preparation 1. Dry blend all powders exception citric acid. 2. Add this dry blend to water while mixing. Add HFCS. 3. Heat syrup mixture to boiling. Continue mixing until reaching 65–70◦ Brix. 4. Add IQF fruit and mix until uniformly dispersed. 5. Remove from heat and pack.

Pumpkin Pie Fillings The tradition of serving pumpkin pie during the Thanksgiving and Christmas holidays merits this filling to be discussed in a heading of its own. The huge demand for pumpkin pie during this time of the year has prompted manufacturers to develop stabilizer mixes and fail-proof recipes for making commercial pumpkin pies that are delicious and as appetizing as home made pies. Where traditionally it has been made with pumpkin puree, eggs, cream or milk, sugar, and spices (consisting of cinnamon, ginger, allspice, and cloves), commercial recipes now include stabilizers to ensure the same quality of pies even after being subjected to processing and storage abuse scenarios.

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As also dictated by demand, there are commercially available canned pumpkin purees for retail and institutional sale. These purees are standardized to a certain solid content and thickness to give the end user a consistent ingredient for the pie, thus eliminating quality variation from season to season or from farm to farm. In order to ensure the proper amount of thickening and water-binding capacity, the best solution is to use a combination of starch and gum. Gums can be used to augment the water binding that is lost during canning of the pumpkin puree. Pumpkin pie can be stabilized with locust bean gum (LBG), carrageenan, konjac, xanthan gum, and modified food starch. Some initial viscosity provided by the konjac and xanthan is required to prevent splattering or spillage during machine filling into crust. A nice short texture is developed by the starch, the LBG provides additional thickening during baking to prevent boil out, and the carrageenan, konjac, and xanthan portions will help to maintain moisture distribution during the cooking process and prevent any unsightly cracks from forming on the surface. This is accomplished by the formation of a gel network. The combination of these ingredients will provide a nice finished appearance and will also allow this product to be frozen for future use. This stabilized pie will be able to withstand freeze/thaw cycles in addition to a reheating step by the end consumer. Custard Filling Originally created in ancient times as a filler and binder for savory dishes, custards have evolved into the delightfully rich dessert that we are now accustomed to. Generally comprised of eggs and cream, this dish is heated until the desired smooth consistency is achieved. Careful attention must be paid to ensure that the eggs do not curdle during this heating phase. Traditional European formulations were adapted in the early nineteenth century by Americans to form the now commonly used pudding formulations. French custard filling is an emulsified, nonacidified milk and creambased system that is traditionally stabilized with starch and egg. Starch acts as a thickener and the egg provides emulsification and additional set to the custard. Formulation adjustments are not necessary unless costreduction measures and extended shelf life by freezing are required, or an instant version is desired. Gums can be used at low concentrations to achieve the same thickening as the starch or the same gelling and

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emulsifying effect as the egg. Carrageenan is a very suitable gum to replace or augment egg reduction in this product while LBG, xanthan, and konjac could also be used to give a firmer set to the finished filling. In instant recipes, the appropriate gum, therefore, is one that is coldwater soluble and would provide gelling without heat activation. A cold gelling carrageenan or an alginate system would be suitable in this case.

Custard Filling Formulation Ingredients Whole milk Sucrose Whole eggs Modified starch Skim milk powder Carrageenan Sodium benzoate Salt Vanilla flavor

% 75.9 12.0 7.0 2.6 1.5 0.8 0.10 0.06 0.04

Preparation 1. Dry blend sugar, starch, skim milk powder, carrageenan, sodium benzoate, and salt. 2. Add dry blend while mixing milk. Mix until uniformly dispersed. 3. Add whole eggs and vanilla. Mix until incorporated. 4. Heat mix to 185◦ F for 1 minute. Fill into containers and cool to 40◦ F.

Lemon Custard Filling Lemon custard filling is quite different from the French custard. It is acidified with lemon juice and it does not normally contain milk. It does contain a substantial amount of egg yolk, which keeps these two products in the same general category. Lemon custard can be adapted for hot or cold process using the same systems as indicated above. Note

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that an alginate system may provide more stability in the lower pH environment of this product. Key Lime Pie Filling Typically a summertime treat, key lime pie can be prepared using either a hot or cold process. Since key lime pie is served cold, crusts tend to get soggy, which mandate these pies to be consumed fresh or stored frozen. Stabilizing key lime filling also poses several challenges to formulators. Key lime is very acidic with a pH as low as 2.8. This alone limits the type of gum stabilizer that can be used. Xanthan, the most stable of all gums over a wide pH range, is a good candidate for this type of environment. Pectin and ␭-carrageenan are additional pH tolerant gum options. Water of hydration is limited in this type of system since there is usually no added water in the formulation. The source of water is mainly key limejuice and free water from condensed milk. If cold processed, the stabilizer needs to hydrate during the preparation time for the pie. Since stabilizer hydration must occur at a low pH in this situation, an extended hydration period should be allotted to allow for complete activation. Most gums require 2 hours to completely dissolve in water but only about 5 minutes for 90% of its viscosity to develop. If heat processing is chosen, hydration time can be reduced and graininess caused by undissolved gum particulates would be eliminated. Nut Pie Fillings Syrup pies generally serve as the basis for the most commonly produced nut-based pie fillings. Pecans, walnuts, and almonds are commonly used as the main flavoring agents in this filling category. Nut pie fillings are low water, high solids, and nonacidified systems made traditionally with sugar or corn syrup, egg yolk, cream, butter, nuts, and stabilizer, traditionally starch. High amounts of butterfat used in these formulations can necessitate the need to use an emulsifying gum, such as propylene glycol alginate (PGA), to prevent separation of oil during baking. Thickening agents such as guar, LBG, and konjac can provide a cleaner flavor release when trying to reduce high starch levels. Bakery Cr`eme and Donut Fillings Bakery cr`emes have been used for many years to fill virtually any type of pastry or cake such as oatmeal cream cookies, cream puffs, cream

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pies, e´ clairs, and cream buns, to name a few. Traditional homemade bakery cream is prepared with milk, flour, eggs, and sugar, and requires careful attention to prevent emulsion separation during cooking. In order to convert this formulation to a commercially viable product, it is necessary to ensure that emulsion stability is achieved. Stabilization can be approached by both physical and chemical means. True emulsifiers such as gum arabic and PGA can be used in conjunction with thickening agents, which will physically limit movement of the oil phase. This two-phased approach will ensure a consistently stable product over time. Additionally, commercially available bakery emulsions offer an excellent alternative to traditionally incorporated flavors. These products, available in a very broad range of flavors, are able to provide excellent flavor characteristics to base formulations that will remain stable during heating and freeze/thaw cycling. Ingredient suppliers now offer professional bakers and food manufacturers simplified, ready-to-use formulations that contain all necessary ingredients for instant dispersion into water or milk. Such formulations often include special types of hydrocolloids, such as alginates, carrageenans, and/or xanthan, which allow the production of high-quality instant bakery cream fillings. Cr`eme Filling Formulation Ingredients Vegetable shortening Corn syrup solids Confectioners sugar (10×) Water Sweet whey Guar PGA

% 31.0 25.0 20.0 20.0 2.50 1.35 0.15

Preparation 1. Combine gum and water using kitchen aid-type mixer. 2. Blend all other dry ingredients together.

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3. Add dry blended ingredients to gum solution and mix for 5 minutes. 4. Add shortening and mix for an additional 15 minutes on high speed. 5. Aerate if needed using an Oakes machine to the desired specific gravity. Toaster Pastry and Snack Bar Fillings Toaster pastry fillings are commonly high solid-fruit fillings such as jam, preserves, or fruit butter. Solids content could be as high as 83% as shown in Table 5.1, quite acidic with pH of 3.3, with a low aw of ∼0.65. This reduced aw value is necessary to ensure minimal water movement to the traditionally dry outside pastry crust. In order to achieve this value, fillings must be comprised of a significant amount of sugar or high fructose corn syrups to depress the aw . In addition, humectants such as glycerin or sugar alcohols can be used. The use of sugar or corn syrups also allows for increased meltability of the filling or heat thinning for increased machinability and ease of deposition into the pastry. An excellent gum choice for this application is pectin due to its stability at low pH, functionality at high solids contents, and ability to provide a set after baking. The use of locust bean or guar gum in conjunction with a modified food starch can also be utilized to control bake stability of the filling and prevent boil out. As shown in the fruit-based filling recipe below, water is limited to that available from the juice and corn syrups. Order of incorporation becomes critical in ensuring that all stabilizing aids are being effectively activated. Incomplete activation can cause limited bake stability and recrystallization of sugars during extended storage. Make sure the stabilizer is afforded proper time with the water source before other competing ingredients are added. Snack and breakfast bar fillings are mainly fruit-based but may also contain yogurt-type fillings. As shown in Table 5.1, these are high solids fillings similar to toaster pastry fillings ranging from 76 to 80% solids, low aw [0.64–0.67], and acidic with pH of 3.8–5.0. The pastry portion of these types of bars is often soft and chewy and, hence, provides greater flexibility for filling selection. A moister filling will provide a completely different textural option for consumers. The function of gums in this application is for water binding, gelation, and bake stability. Many other gums are also suitable for this type of application like pectin, guar, xanthan, cellulose gum, carrageenan, sodium alginate, and cellulose gel.

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Pastry Filling Formulation Ingredients Corn Syrup (82 Brix) HFCS (75 Brix) Apple powder Glycerin Apricot powder Strawberry fruit juice Pectin/guar blend Modified food starch Citric acid Malic acid Food, Drug, and Cosmetic Red Color # 40 (12% sol) Strawberry flavor

% 47.46 30.62 9.99 3.85 2.68 2.46 0.7–1.2 1.10 0.20 0.20 0.14 0.10

Preparation 1. Warm corn syrup and glycerin. Add to mixer. 2. Add Pectin/guar blend, starch, color, apricot powder, citric and malic acids. Mix for 5 minutes. 3. Add concentrated fruit juice, fruit flavor, and apple powder. Mix for 5 minutes. 4. Add 50% of the HFCS. Mix for 2 minutes. 5. Add remainder of HFCS. Mix for 3 minutes. 6. Pour filling into pastry while hot.

Factors Affecting Filling Stabilization Water Activity One of man’s earliest discoveries for preserving food must have been the fact that fresh foods become less perishable when water content is reduced. However, the importance of controlling moisture content to preserve food wasn’t given scientific basis until the early twentieth century. Although water was known to be the most important factor in determining spoilage of a food, it was inadequately understood as

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to why some food products showed different stability and spoilage patterns at the same water content. This and comparable phenomena in food deterioration had been poorly explained until the realization that actual water content was not the culprit, but that the nature or state of the constituent water determined eventual spoilage. Chemical, physical, and biological properties, and hence the quality and stability of food products, are related directly to the equilibrium relative humidity or the aw of the system. Water activity is an indirect measure of the available water for growth of microorganisms. At aw of 0.85 or lower, bacteria are unable to grow. However, aw alone does not completely prevent yeast and molds from potentially spoiling the filling if stored without refrigeration. The combination of low pH, reduced aw , and heat, however, will provide enough protection against microbial spoilage. Stability of baked goods is not normally compromised with the use of filling even with aw of higher than 0.85 when processed accordingly. Concerns arise when using high aw fillings with respect to moisture migration from the filling into the pastry or crust. Water activity of the pastry or piecrust is normally lower than the filling, thus creating a gradient between the two layers. Moisture migration will always occur from an area of high aw to low aw which, in this case, will be from the filling to the crust. Softening or sogginess will occur over time. This is commonly seen in turnovers, strudels, and croissants due to the high moisture content of the fillings used. While the use of gums manages water by binding, immobilizing, or gelling, gums are large molecules that are not effective in depressing aw of fillings. This immobilization and gelling of water will delay or slow down moisture migration, but will not prevent the sogginess of crust from occurring, and given time, aw equilibrium is reached between the two layers. Therefore, high aw fillings will need ingredients that will depress aw , such as increased sugar concentrations, humectants, or high levels of fat in case of nonacidified fillings such as butter cream and marshmallow-type fillings. pH The use of acid to lower pH of foods had been tried in many food systems to give the finished product additional security against microbial spoilage while enhancing the natural flavor of the product. Most fruits

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have natural acids present that lower the pH of the filling. Combined with heating or cooking, a pH below 4.6 is sufficient to preserve the finished pies or pastries until they are consumed. Variability of acid levels in fruits make it necessary to standardize acid content to ensure proper pH of the product. Citric acid is commonly used, however, other acids such as malic, fumaric, and tartaric can be added to boost the natural acidity of the fruit used in the filling. In cases where fruit fillings are overly tart or too sour, buffers such as sodium citrate can be used to reduce the overall effect on the palate. Cream fillings, on the other hand, are nonacidified or low acid with pH ranging from 5.4 to 6.8 as shown in Table 5.1. Basic cream fillings are made with milk components and tend to maintain a near neutral pH status. In this case, heat treatment becomes a critical processing step in maintaining filling stability. Water and Solids Content When gum is used in bakery fillings, it is very important for the processors to know how much water is present in the recipe since this dictates the usage level of the gums. Gums are hydrocolloids; in other words, they require water to be functional. It is always best to use gum in bakery fillings where they can fully hydrate or where full activation is possible. This means that the usage level for the gum should be based on the total water in the recipe, estimated from the water added plus the water content of ingredients like fruit, syrups, milk, egg, cream, and others. Water content (% moisture) of bakery fillings varies widely in commercially available products, from 1 to 88% as shown in Table 5.1. As expected, fruit pie fillings are on the high end with water content of 70–88% while shortening-based fillings tend to the lower side. Interestingly, frozen pie fillings range from 63 to 70% water. This decrease in moisture content in frozen products could be an effort to reduce any defects caused by excessive ice-crystal formation during freeze/thaw cycling. Fillings that are high in water content, like pumpkin, apple, and cherry pie fillings, can provide an ideal environment for water migration from the filling to the crust or pastry resulting in a soggy pastry. Additionally, fluid migration of fruit filling is possible during heating due to the decreased viscosity state of the filling.

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Processors must know the target viscosity of the pie or pastry fillings during pumping, filling, and baking to ensure a continuous flow of the product through the system and adequate suspension of particulates, and prevent boil out during the critical heating phase of the process. Processing Conditions Processing conditions for the preparation of bakery fillings play a role in the selection of suitable stabilizing systems. For example, if a filling will be pumped through a filler, there is a required viscosity to prevent splattering during machine filling into the crust and maximum viscosity for proper pumping. In this instance, fruit fillings must remain fluid enough to be pumped but still be able to build additional viscosity during the baking step to prevent boil out. These fillings, therefore, require a specially designed stabilizer system that will impart filling viscosity and additional thickening during the cooking step. Such a system could be a blend of ingredients to include starch, LBG, tara, konjac, and guar. LBG and tara gum are partially cold-water soluble and thicken fully during the heating step. Konjac and guar are both cold-water soluble and can be used in combination with either LBG or tara gum to provide additional cold viscosity for the suspension of the fruits. Another approach could be to use methylcellulose in fillings with pH greater than 3.5 in combination with other gums to provide thickening during the baking step. Starch, both cook up and instant, is traditionally used in bakery fillings. Acid degradation is common when using native starches, hence, acid and heat resistant starches are best used in place of native starches. Available shear In order to successfully incorporate gums into a system, it is necessary to either provide a method for dispersing gums or provide adequate shear. Bakery filling recipes such as fruit pies and turnover fillings generally contain a portion of dry ingredients, such as sugar, that can be used as dispersing agents for the gum. Formulations containing glycerin or a liquid oil source can also be used to disperse gums into a water system. In instances where dry ingredients are not present and no other dispersing aid is available, the use of high shear becomes a necessity for hydrating gums. All cold-water soluble gums and even those that are partially cold-water soluble will lump and form fish eyes

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when added without a dispersing aid directly to water under insufficient mixing. Utilizing a high-speed mixer with an attached propeller blade will create a vortex, which will maximize gum hydration and minimize the chances of lumping. Heat treatment The requirements for the thickener vary depending on whether heat treatments are part of the process. Gelling gums such as agar, pectin, and carrageenan require heat to activate, hence, these gums cannot be used in cold-set fillings. Traditional agar requires boiling to dissolve, while pectin and carrageenan require at least 180◦ F to activate. All gelling gums thin out drastically when heated, hence, they should be used in conjunction with other thickeners to prevent boil out. When fillings thin out, in addition to the molecules moving more easily, they heat faster and can reach boiling temperatures during baking and cause boil out. Sodium alginate is a heat stable gel, and methylcellulose gels when heated. Both provide excellent boil out protection. LBG and tara gum are partially soluble in cold water, tara gum more so than LBG. These gums require 180◦ F for full hydration. The additional thickening during the baking or heating step gives these gums an advantage in preventing boil out. Xanthan gum, which is cold-water soluble, is very unique in the sense that it maintains a relatively stable viscosity from 40 to 212◦ F. Guar gum, konjac, and starches also play a vital role in providing bake stability. Storage Time/Conditions Many bakery fillings are meant to be shelf stable, hence, certain conditions need to be met. Common hurdles to ensure microbial stability of fillings are aw , pH, and temperature. An aw of <0.85 combined with heating is normally sufficient to keep the finished product microbiologically stable until it is consumed. The combination of pH <4.6 and temperature also provides microbial stability to bakery fillings during its market shelf life, and in many instances the combination of these 3 hurdles comes into play in the preservation of the finished products. Conditions to be met for a product to be shelf stable are pH below 4.6 and aw of 0.85 or less combined with pasteurization or some form of heat processing. Most fillings would meet the cooking criteria because of the baking step. The pH requirement, however, is only met by the acidified fillings with fruit.

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Gums Used in Bakery Fillings The structural, textural, and shelf-life properties of bakery fillings are key quality attributes heavily impacted by the ingredients they contain that in turn dictate the stabilization that is required. In addition, the variability by which a filling is prepared, used, cooked, and stored results in the use of different gum systems to stabilize it. The diversity of hydrocolloids begins in nature and ends in the lab and, as expected, the possibilities for stabilization have become quite diverse as well. In many instances, the simplicity of the gum label, whether it is all-natural, genetically modified organism (GMO)-free, or organic, dictates the type of stabilizer to be used in bakery fillings. In other scenarios, the use of a combination of gums to take advantage of their synergy and reduce cost of the stabilizer is more important. The result is a gamut of stabilizers that encompass a broad range of hydrocolloid thickeners and gelling agents used in combination with starches whose textures, sensory characteristics, and compatibilities have been studied and optimized. Gums do not form true solutions in water but colloidal suspensions. Their unique interaction with water gives them the more technical name, hydrocolloid. They are long-chain polymers of high molecular weight that could be linear, linear substituted, or branched. Their solubility in either cold or hot water depends largely on their chemical structure and the presence or absence of electrical charge on the molecule. Gums dissolve in water forming hydrogen bonds. However, thickening or gelling results from intermolecular hydrogen bonding between hydrated gum molecules forming an ordered matrix or micelle that traps and immobilizes water. Depending on the extent of the intermolecular association, the water is either thickened as measured by a parameter called viscosity or completely converted into a gel that resists flow and behaves more like a solid. Therefore, gums are used in bakery for viscosity control; some are used mainly for gelling and a few possess a true emulsifying property and find usefulness in emulsified systems such as cr`eme fillings. Locust Bean Gum [E410; CAS#9000–40-2; 21CFR184.1343; FEMA#2648] LBG or carob bean gum is one of the seed gums used in foods and it is derived from the endosperm of carob seeds of the tree Ceratonia siliqua. Chemically, it is a nonionic polysaccharide that consists of a linear polymer of mannose linked by ␤-(1→4) glycosidic bonds

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with galactose substitution at C-6 position of the mannose occurring at the regularly substituted region at every 4 mannose units. There are regions in the molecule that is more substituted and regions where galactose substitution happens every 10–11 mannose units (Welinga, 2000). Galactose content of LBG is reported by Welinga (2000) to be between 17 and 26%. The linear mannose chain is quite similar to cellulose, hence, without the galactose substitution, this gum will be insoluble in water. The lower galactose substitution for LBG compared to other galactomannans is the reason why it is only partially cold-water soluble. Heating to 180◦ F will fully activate LBG; however, when its solution is frozen, LBG reverses to being partially insoluble. Therefore, LBG will lose some functionality in frozen bakery fillings. The benefit of using LBG as thickener and stabilizer for fillings is the fact that it provides additional thickening during the baking step and this will help prevent boil out. Fully hydrated LBG has a viscosity of 2,500–3,300 cP at 1% concentration in water and like all other gums, its viscosity increases exponentially with concentration. By itself, texture of LBG in water is quite short, resembling to some extent the texture of starches that is desirable for pie filling. In pop tart filling, it can be used in combination with pectin to provide hot viscosity and prevent boil out. Locust bean exhibits a strong synergy with xanthan gum. Not just that the gum forms a gel when used alone but together their water binding property is dramatically improved. A 60/40–50/50 blend LBG/xanthan yields the most synergistic ratio (Sworn, 2000b). At concentration up to 0.4% of the total gum blend, its heated solution shows a very pseudoplastic gel-like behavior; between 0.4 and 1.0% it is a soft gel with increasing firmness and at 1% or higher, it forms an elastic gel that is not prone to syneresis. It is also synergistic with ␬-carrageenan. It increases the gel strength of ␬-carrageenan, the optimum ratio being around 20/80 LBG to carrageenan. LBG makes the carrageenan gel more elastic and this is shown by the shift in the fracture point of the gel during compression testing. The same type of synergy is exhibited by LBG and agar. The synergy also gives stability to the carrageenan gel that allows the use of carrageenan in fruit fillings with pH between 3.0 and 5.0. Guar Gum [E412, CAS#9000–30-0; 21CFR184.1339; FEMA#2537] Guar gum is a ground endosperm of the guar seed of the leguminous shrub Cyamopsis tetragonoloba. Guar gum is a galactomannan similar

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to LBG consisting of a linear mannose chain linked by ß-(1→4) glycosidic bonds and with galactose substitution at C-6 position of every 2 mannose units. Guar gum is made up of nonionic polymers consisting of molecules longer than found in LBG and made up of about 10,000 residues. Higher galactose substitution (Petkowicz et al., 1998) increases the solubility of this galactomannan compared to LBG and makes guar cold-water soluble. The galactose residues prevent strong chain interactions or intermolecular hydrogen bonding during drying of the powder. The usefulness and popularity of guar gum as a multipurpose thickener is attributed to its cost. The standard grade of guar gum has a viscosity of ∼4,500 cP at 1% in water and combined with its lower cost, it is by far the most economical thickener a formulator could use for stabilizing foods. It hydrates fairly rapidly in cold water to give a more viscous but less pseudoplastic solutions compared to xanthan. It has the same type of texture as the heated LBG solution that is quite short and hence, guar gum could be used to replace the lower costing starch to some extent as a viscosifier in bakery fillings. Because of its solubility in cold water, guar gum shows better stability to freeze-thaw cycles than LBG and, hence, it is more functional in bakery filled products that are frozen. It means that on thawing, guar gum regains its water binding property whereas LBG would only partially hydrate. The rule of thumb is that gums that are cold-water soluble are also freeze-thaw stable. A minor drawback in using guar gum in foods is its strong beany smell and taste that could be a problem in cold applications. Cooking removes the beany note and it is not really an issue when using gums in products that are cooked. However some bland tasting and smelling guars with high viscosity have been developed that could be used in cold-processed products. Other grades of guar that are commercially produced include partially hydrolyzed and lower viscosity grades and those that are chemically derivatized such as the hydroxyproyl guar and the cationic guar grade. Pectin [E440; CAS#7664–38-2; 21CFR184–69-5] Pectin is produced from citrus peel from the extraction of lime, lemon, and orange juices, or from apple pomace, the dried residue from the extraction of apple juice. Pectin is a heteropolysaccharide in its native

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state, but the extraction with hot mineral acid removes most of the branched or hairy region containing neutral sugars such as rhamnose, galactose, arabinose, and others, leaving mainly the more stable galacturonate block that makes up the smooth region. The majority of the structure of pectin molecule, therefore, consists of homopolymeric chain of ␣-(1→4)-D-galacturonic acid that is either free or partially esterified with a methoxy group (P´erez et al., 2000, 2003). By definition for use in food and pharmaceuticals, pectin contains at least 65% galacturonic acid. By convention, if the degree of esterification (DE) is greater than 50%, the pectin is a high methoxy (HM) grade or high ester and if less than 50%, it is called low methoxy (LM) pectin or low ester. Depending on how the extraction process is controlled and how much de-esterification happens, pectin can have DE as high as 77% and as low as 20%. Low ester pectin with amidation is also produced commercially. Pectin is used mainly in bakery fillings for its gelling property and this is influenced by its DE. HM pectin that has a DE greater than 69% is a rapid set pectin, whereas a pectin with DE of 60–61% is a slow set pectin. This means that when conditions for gelling are met, the rapid set will gel at a higher temperature and depending on the cooling rate it will set the product faster. In other words, gelation is both time and temperature dependent. Conversely, the slow set pectin will set at a lower temperature and slower giving more time for the processor to apply the filling before the product sets. May (2000) reported that HM rapid set pectin sets at temperature as high as ∼85◦ C at pH of 3.0 or at ∼70◦ C at pH 3.2, while the HM slow set sets at ∼58◦ C at pH 2.8 and at ∼50◦ C at pH 3.0. A special grade of HM pectin with DE between 50 and 60% is also commercially produced. It is called “extra slow set.” Gelation of HM pectins requires a pH below 3.5 with optimum around 3.0–3.2, sugar solids of 60–65% and heating to fully hydrate and activate the pectin molecule. The acidity of the fruit used in the filling may or may not be enough to achieve this pH. In case an adjustment is required, citric acid and other acidulant could be used. The pH adjustment is necessary to protonate the free carboxyl group of the unesterified galacturonic acid units and reduce the negative charge on the pectin molecule and the electrostatic repulsion. The combination of high sugar concentration, low water, and the protonation or neutralization of the negative charge on galacturonic acid causes the pectin molecules to associate with each other through intermolecular hydrogen bonding

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resulting into a gel formation. However, premature gelling could take place especially with rapid set pectin that could pose pumping and application problem and this happens more so if the pH is lower than 3.0 and the sugar concentration is higher than 65%. When making high Brix or high sugar jelly with sugar greater than 70%, a buffered slow set pectin should be used instead. Gels using HM pectin are thermoirreversible or in other words, when broken, they cannot be remelted to reform the gel structure. Gelation with conventional LM pectins requires the use of a calcium source, sugar solids ranging from 20–55%, and pH of 3.0–5.0. Low methoxyl-pectins (<40% esterified) gel by calcium dication bridging between adjacent twofold helical chains forming so-called ‘egg-box’ junction zone structures so long as a minimum of 14–20 galacturonic acid residues can cooperate (Ralet et al., 2001). Gel strength increases with increasing Ca2+ concentration but reduces with temperature and acidity increase or lowering of pH below 3.0 (Lootens et al., 2003). Gelation with amidated LM pectin, on the other hand, only requires a calcium source and pH adjustment to gel and it works even in sugarfree formulations without sugar solids and in high Brix jelly recipes containing as high as 80% sugar. Gels produced using LM pectin are thermoreversible, meaning that they can be remelted and the gels reform on cooling, hence, making it functional in ready-to-use fruit filling for use in toaster pastry and snack bar filling that allows the filling to be remelted for ease of application and set afterward. Alginates Sodium alginate [E401; CAS#9005–38-3; 21CFR184.1724; FEMA 2015] Alginate is extracted from brown seaweeds of the family Phaeophyceae. Commercial sources are several Laminaria species, Macroscystis pyrifera, Ascophyllum nodosum, Eclonia sp., Lessonia nigrescens, Durvillae antarctica, and Sargassum spp. (Draget, 2000). It is present in the seaweed as a salt of sodium, calcium, magnesium, strontium, and barium in a gelled form; hence, the first step in the extraction is an acid treatment to convert the alginate into alginic acid, then followed by alkali [Na2 CO3 or NaOH] treatment to produce the water soluble sodium alginate. The sodium alginate is recovered by direct precipitation with alcohol or calcium chloride, and then dried.

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Alginates are linear unbranched polymers containing ß-(1→4)linked D-mannuronic acid (M) and ␣-(1→4)-linked L-guluronic acid (G) residues, and are, therefore, highly anionic. Alginates are not random copolymers but, according to the algae source, they consist of blocks of similar and strictly alternating residues (i.e., MMMMMM, GGGGGG, and GMGMGMGM), each of which has different conformational preferences and behavior [Source: http://www.lsbu.ac.uk/water/hyalg.html]. As examples, the M/G ratio of alginate from Macrocystis pyrifera is about 1.6/1 whereas that from Laminaria hyperborea is about 0.45/1. Alginates may be prepared with a wide range of average molecular weights (50–100,000 residues) to suit the application. Commercial grades that are high in guluronic acids are usually labeled HG. Gelation of alginate with calcium or a bivalent ion is instantaneous, an amazing property that is used in show-and-tell demonstrations on alginate. The G-block responds to calcium cross-linking faster because of its egg box conformation replacing the water molecule that is bound to the carboxylate. Ca2+ ions can replace this hydrogen bonding, zipping the guluronate chains, but not mannuronate, and forming a more rigid gel with good heat stability (Donati et al., 2005). Under similar conditions, polymannuronic acid blocks take up a less-gelling ribbon conformation, where carboxylate groups on sequential residues may bind calcium intra- or intermolecularly forming weaker but more elastic gels. Where gelation is the required functionality in an application, a high guluronic alginate is used whereas a high mannuronic alginate is used where thickening more than the gelling is the desired attribute. Different viscosity grades of either high G or high M alginates are commercially produced and some alginate grades incorporate a sequestering agent to reduce calcium sensitivity. In bakery fillings, the proper choice of alginate can reduce or prevent syneresis in baking jellies with acceptable textural attributes. Also advantageous is their stability at high baking temperatures (Dorner and Tessmer, 1953). Sour cherry pie fillings are stabilized with alginates (Strachan et al., 1960). Improved clarity in canned and frozen peach and cherry pie fillings can be achieved by combining alginate with a modified waxy maize starch (Kunz and Robinson, 1962). Alginates also offer freeze-thaw stability to pie fillings, the high mannuronic alginates providing better protection. When using alginate in acidic fillings, pH

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should be carefully controlled because sodium alginates precipitate at pH ≤3.5 rendering them nonfunctional. Propylene glycol alginate [E405; CAS#9005–38-3; 21CFR172.858; FEMA#2941] Sodium alginates have poor acid stability and are highly calcium sensitive, which is a drawback in many applications because of processing and timing issues with premature gelation. These limitations are removed via chemical modification of the alginate into PGA. In fact, this chemical modification gives entirely new properties to the native gum. PGA is chemically derived by treatment of the alginate with propylene oxide. This treatment introduces as a propylene glycol ester groups bonded to the carboxyl group of the guluronic and mannuronic units. The conversion of alginate or alginic acid to PGA reduces the charge on the molecule to a minimum and changes the behavior of the polymer in many ways compared to standard alginate. Esterified alginate is less calcium-sensitive, thickens to some extent in the presence of calcium ions but does not gel, tolerates low pH such as those of fruit fillings, and the esterification gives PGA superior emulsifying and foaming properties that expand the use of alginate in salad dressings, sauces, and marinades, foam stabilization in beer and whipped toppings and various icings. PGA also works well with starch to give smooth creamy texture to various bakery cream fillings. Cellulose Derivatives Cellulose is the most abundant natural resource on earth that is directly consumed as human and animal food. It is the insoluble material found in all fruits and vegetables that makes up the insoluble dietary fiber in our daily diet. Leaves, trunks, and bark of plants contain cellulose as a structural component and it is also the chemical make up of cotton that is used as clothing material. No wonder that powdered food-grade cellulose is now being commercially produced from nontraditional sources such as pine tree and cotton linters as a direct food additive or as a base material for a number of highly functional water-soluble derivatives with predesigned and wide-ranging properties dependent on groups involved and the degree of derivatization. Derivatizing cellulose interferes with extensive intermolecular hydrogen bonding and orderly crystal-formation of the native cellulose

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by introducing various functional groups into the free hydroxyl groups of the glucose units. A methyl ether, a carboxymethyl and other substitutions have yielded gums that are either nonionic or anionic possessing unique functional properties such as thermal gelation and superior clarity. Two of these derivatives are discussed in detail, namely, methylcellulose and carboxymethylcellulose (CMC). In addition, microcrystalline cellulose, a physically modified and functionally improved cellulose that forms a gel suspension under high shear, is included in this section. Methylcellulose [E461, CAS#99638–59-2; 21 CFR§182.1480;] Methylcellulose is a chemically derived cellulose with a methyl substitution of 1.6–1.9 at C-2, C-3 or C-6 positions of the glucose units. Although nonionic, the addition of the methyl ether group to the cellulose backbone gives this gum a unique property such as cold water solubility and thermal gelation or gelling with heat. Methylcellulose gels between 48 and 64◦ C depending on the grade. This means that it will hydrate and form a thick solution in water at room temperature and upon heating, or during the baking step as in the case of bakery filling, it will gel or thicken the product depending on usage level. Upon cooling it loses the gel structure to become fully dissolved again. At concentration of 2% in water and higher, methylcellulose solutions will gel into a solid mass and will maintain this gel structure as the product temperature increases. This gelling forces the heat transfer from convection to conduction that subsequently limits the movement of the product and prevents boiling out of the filling during baking. Methylcellulose is stable over the pH range of 3–11 (Murray, 2000) and will work in a variety of fillings listed in Table 5.1. At least 2 viscosity grades are commercially sold, a low-viscosity methylcellulose with a 4% viscosity of 380–570 cP and the highviscosity grade with a 2% viscosity of 3,800–5,700 cP. In bakery fillings, the high-viscosity grade could be used at 0.5–0.8%. Methylcellulose is best used by dispersing it in warm water at >140◦ F and adding it to the cold batch to dissolve. Alternatively, it can be dry-blended with the dry ingredient such as sugar, hydrated in cold water until fully dissolved, filled, and baked. It cannot be heated prior to or during pumping of the filling because its viscosity can drastically increase or become too thick to pump and could cause clogging of the line. The thermal gel structure also reduces moisture loss during heating. Yet, since the thermal gel

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structure goes away as the product cools, the finished products get the desirable attribute rather than the gelled matrix.

Carboxymethylcellulose or cellulose gum [E466; CAS#:9004–32-4; 21CFR 182.1745] CMC is a cellulose derivative that is mainly used in a variety of food applications for its viscosity or water binding property and clarity in solution. There are several grades of CMC that are sold on the basis of viscosity ranging from ∼50 cP at 2% concentration in water to 13,000 cP at 1%. For most applications, the use of the high-viscosity grade is chosen for economic reason because the price of CMCs is dictated more by ease of processing rather than the viscosity each grade provides. However, in other applications, the rheology of the CMC and the absence of graininess in solution due to unsubstituted and insoluble regions in the molecule are sufficient reasons to use the lower viscosity grades, which are less prone to this problem. The CMC structure is based on ␤-(1→4)-D-glucopyranose polymer of cellulose with carboxymethyl substitution at C-2, C-3, or C-6 position of each glucose unit. CMC is anionic because of the terminal carboxylate that is commercially produced in form of a sodium salt, which ionizes to COO− when CMC is dissolved in water. The degree of substitution (DS) could vary from lot to lot of CMC but it is generally in the range 0.6–0.95 per monomer unit. The higher the DS, the more soluble and stable the CMC is; however, the uniformity of the substitution also influences solubility of the CMC and further the rheology and absence of graininess of CMC solutions. At acidic pH of 3.0 or lower, CMC becomes insoluble and loses water binding, hence, it cannot be used in key lime pie filling and some fruit pie fillings that are normally close to pH 3.0 or lower. CMCs are smaller molecules than the parent cellulose and the different CMC grades also vary in degree of polymerization (DP) and molecular weight. Smaller molecules (or low DP) produce lower viscosity and the large molecules (high DP) produce higher viscosity due to a tighter matrix formed from intermolecular association when longer CMC chains are involved. In 4 + 1 fruit preparations that are used in jams or pie fillings, a high viscosity CMC is used in combination with a modified starch to provide thickening and suspension. CMC is also used in aerated cr`eme

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fillings to improve foaming and whipping property of the mix and also in nonaerated cr`eme fillings for viscosity control. Microcrystalline cellulose [E460(i); CAS#99331–82-5 Microcrystalline cellulose (MCC) is produced using cellulose powder as base that is subjected to acid hydrolysis to reduce the molecular length of the wood pulp from 1,000 to 1,500 DP to 200–300 DP (Iijima and Takeo, 2000). MCC, like unprocessed cellulose, is a linear polymer composed of glucose linked by ␤-1,4 glycosidic bonds. MCC has a shorter chain length than the unprocessed form. The glucose and cellooligosaccharides that also form during acid hydrolysis are removed by washing. The refined MCC wet cake, which contains only the pure crystalline region of the natural cellulose, is mixed with water, neutralized, and dried to produce powder-type MCC grades. This grade is insoluble and harder to swell with shear because the microfibrils reform to a great extent from intermolecular hydrogen bonding between cellulose polymers during drying. Colloidal grades are also produced by coprocessing the wet cake with another hydrocolloid, such as CMC, to coat the crystalline cellulose and to minimize reaggregation of the fibrils during subsequent drying. Hence, this grade can be dispersed uniformly when mixed in water with adequate shear, a property that is used by formulators to mimic mouthfeel of fat in fat-free and reduced-fat products. The usefulness of colloidal MCC in bakery fillings is attributed to its thixotropic behavior. Because it thins out, as its solution is mixed, it can be used in high water fillings such as fruit pie and donut fillings where it will be thin during mixing and pumping and then thickens once the shear is removed. In addition, it also adds microscopic particulates in the product that will deter flow of the filling once inside the donut, or during baking as in the case of fruit pie that will help reduce boil out. Konjac gum [E425; CAS# 37220–17-0] Konjac gum is a hyrdocolloid derived from the root of the plant Amorphophallus spp. It is synonymous to konjac mannan and konjac glucomannan. Konjac formulated foods are traditional Chinese foods with a history spanning over 2,000 years and are a popular health food in the Asian markets. Konjac is a heteropolysaccharide that consists of glucose and mannose in the ratio of 5:8 (Shimahara, 1975b) and joined by ␤-D-1,4

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glycosidic bonds. It is slightly branched (every 50–60 sugar units) via a C-3 bond on hexoses of the main polymer chain (Shimahara, 1975a; Kato, 1973), and it contains approximately 1 acetyl group per 19 sugar residues (Maekaji, 1974) making it slightly anionic. The molecular weight of konjac depends to a certain degree on the species or even the variety of amorphophallus it is derived from and also on the method of extraction. Sugiyama (1972) found values of 0.67–1.9 million Da (weight average MW) depending on the amorphophallus variety. Konjac solution gels if heated after alkali addition, and this gelling is as a result of the hydrolysis of the acetyl groups, where the OH-groups are no longer hindered by the acetyl groups to form intermolecular hydrogen bonding, as explained by Maekaji (1978). A further interesting characteristic of konjac gum lies in its synergy with other hydrocolloids. Takigami (2000) reported synergy between konjac mannan–xanthan forming an elastic gel, and a significant increase in gel strength with konjac mannan–carrageenan and konjac mannan–agar. Furthermore, the uniqueness of konjac mannan is that it produces a viscosity as high as 30,000 cP at 1%, the highest viscosity ever reported for any gum. Konjac gum solutions are also pH-stable and heat-stable; and unlike xanthan gum, konjac has a smooth texture and flow. Konjac alone or in combination with tara and guar gum provides a high intensity thickener that could replace starch in fruit filling that is acid, heat, and freeze-thaw stable. Xanthan gum [E415; CAS#11138–66-2; 21CFR172.695] Xanthan gum is a polysaccharide that is produced by a bacterium Xanthomonas campestris during a fermentation process involving a carbohydrate substrate and other growth-supporting nutrients. This gum is actually an excretion to protect the bacterial cells when pH of the fermentation medium becomes too low and unfavorable for growth. It is likely that xanthan gum possesses superior stability over the other gums because of this protection function. It is stable over a wide range of pH from 1 to 13, is very resistant to enzyme hydrolysis, is tolerant to high salt, high sugar, and high alcohol systems, and is stable at boiling temperatures, and tolerates retort processing better than many other gums. Xanthan gum is an anionic polymer with a molecular structure elucidated by Jansson et al. (1975) and Melton et al. (1976) to be

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consisting of a linear glucose chain linked by ␤-(1→4) glycosidic bond with a trisaccharide substitution occurring at every 2 glucose units. The trisaccharide is composed of an inner mannose that is linked to glucose by ␤-(3→1) glycosidic bond and partially acetylated at C-6 position, a glucuronic acid, and a terminal mannose that is partially pyruvated at C-6 position. The repeating unit of xanthan, therefore, is a pentamer. Each molecule consists of about 7,000 pentamers. Xanthan gum is soluble in cold water and like most powders that thicken cold, it forms lumps if mixed in water with insufficient agitation. It forms viscous solutions with water; and at 1% concentration, its solution gives a viscosity between 1,200 cP and 1,600 cP. Xanthan solution is highly pseudoplastic, shows a more drastic decrease in viscosity with shear rate, and can have a soft gel-like consistency depending on concentration and shear applied. Although xanthan is thinner at ≥1% concentrations, at lower concentrations such as 0.1–0.5% it has a relatively higher viscosity than the thicker gums such as guar or CMC. The superior suspending property of xanthan gum is attributed to its weak-gel, shear-thinning properties. It hydrates rapidly in cold water even in the presence of high sugar, salt, or alcohol. The consistent water holding ability may be used for the control of syneresis and to retard ice recrystallization in freeze-thaw situations. Xanthan gum shows superior freeze-thaw stability (Giannouli and Morris, 2003). Being relatively unaffected by ionic strength, pH (1–13), shear, or temperature, it may be used in products such as key lime fillings for viscosity control or in aerated cr`eme filling for foam stabilization. Xanthan is not used in fruit fillings because of its gel-like texture; but in combination with starch and another gum such as konjac, an acid stable, heat stable, and freeze-thaw stable filling can be produced. Xanthan gum is capable of synergistic interactions with galactomannans such as guar, tara, and LBGs and with another glucomannan such as konjac gum. With guar, a boost in water binding and viscosity is achieved at all ratios, the optimum being at 75:25–80:20 guar to xanthan. With LBG optimal synergy being obtained at 50:50 ratio (Goycoolea et al., 2001), the blend producing an elastic gel is thermoreversible and is not prone to syneresis. Tara gum provides synergy with xanthan in between that provided by guar and LBG. An extreme synergy between xanthan and konjac mannan takes place at optimal ratio of 80:20 konjac to xanthan with a viscosity buildup as high as 161,000

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cP at 1% total gum (Takigami, 2000), allowing very low usage for this gum combination in many food applications including bakery fillings. Carrageenan [E407; CAS# 9000–07-1; 21CFR 172.620; FEMA #2596] Carrageenan is a collective term for polysaccharides extracted from certain species of red seaweeds in the family Rhodophycae. Commercial sources are Eucheuma spinosum, Eucheuma cottonii, Gigartina spp. and Chondrus crispus. There are four types of carrageenan extracts in terms of chemical makeup and structure such as kappa I, kappa II, iota, and lambda types. Different seaweeds produce different carrageenans with one type being predominant in any species of seaweed. Purer ␬- and ␫-carrageenans can be produced following potassium chloride precipitation where kappa and iota fractions are made insoluble while the lambda is removed in the soluble phase. Physical separation of different species of seaweed or picking of seaweed contaminants are also good ways to obtain high quality fractions. Carrageenans are made up of alternating ␤-galactose and ␣-3,6anhydro-D-galactose dimer linked by ␤-[1→4] and ␣-[1→3] glycosidic bonds that are sulfated either at C-2, C-3, or C-6 of the galactose or C-2 of the anhydrogalactose unit. Carrageenans are linear polymers of about 25,000 galactose derivatives with regular but imprecise structures, dependent on the sources and extraction conditions (Falshaw et al., 2001). The difference between the 4 types of carrageenan is in the degree of sulfation, kappa I being the least sulfated with 25% ester sulfate content and the lambda having the most with 35%, giving the carrageenans varying degrees of negative charges and solubility in water. Lambda carrageenan is completely cold-water soluble, while ␫- and ␬-carrageenans are only partially cold-water soluble and require heating to 180◦ F for full activation. Instant bakery filling creams require gum to be cold-water soluble. In this application, the ␭-carrageenan is the best type to use. In this application, carrageenan provides creamy texture and mouthfeel, excellent flavor release, and glossy appearance to the cream and improves freeze-thaw stability. In pumpkin pie filling, a ␬- or ␫-carrageenan is more suitable to use in conjunction with the starch to give the filling a set and a short texture. An LBG could be used in conjunction with the carrageenan to give the desired synergistic effect. The use of a gelling carrageenan

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in this application produces tender pie slices which retain their shape, gives glossy surface appearance, prevents surface cracking and skin formation, and controls syneresis.

Agar [E406; CAS#64–19-7; 21CFR 182.101; FEMA# 2006] Agar is extracted from the same family of red seaweeds (Rhodophycae) as the carrageenans. The major commercial sources are Gelidium sp. and Gracilaria sp. Agar consists of a mixture of a gelling fraction called agarose and a nongelling fraction called agaropectin that is slightly branched and sulfated. In the manufacture of commercial food grade agar, most of the agaropectin is removed during the freezing and thawing process giving the resulting agar a higher gel strength. Typical gel strength for a Gelidium agar is ∼720 g/cm2 at 1% gum in water while Gracilaria agar has a slightly higher gel strength at ∼850 g/cm2 . Agarose is a linear polymer, with a molecular weight of about 120,000 Da and with similar structure as the carrageenan except for presence of 3,6-anhydro-L-galactose rather than 3,6-anhydro-D-galactose units and the lack of sulfate groups. The applications for agar are based on its gelling power and its better stability at low pH and high temperature compared to other gelling systems. Gelation is a result of the formation of a network of agarose containing double helices. These double helices are stabilized by the presence of water molecules bound inside the double helical cavity (Labropoulos et al., 2002). Exterior hydroxyl groups allow aggregation or intermolecular hydrogen bonding of up to 10,000 of these helices on cooling of the agar solution to form suprafibers or gel. The only drawback with agar use is its cost. Agar is a high-cost ingredient and, because of this, its usefulness in foods has diminished. Applications where agar has survived replacement are in fruit slices where the combination of pH and heat treatment would normally break down all other gelling agents, and in gelatin replacement in vegan marshmallow or marshmallow fluff that is used as bakery filling. Traditional agar is insoluble in cold water and requires boiling to dissolve. The nonionic nature of agar induces intermolecular aggregation during drying of the agar powder, similar to the formation of cellulose microfibrils; and energy in the form of heat is required to free up the individual polymer chain and redissolve the agar molecules. Freezing reverses agar to its cold-water insoluble state. Therefore, agar

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lacks freeze-thaw stability and is not suitable in applications where the product is frozen prior to use or prior to consumption. Gellan gum [E418] Gellan gum is a bacterial exopolysaccharide like xanthan that is produced from aerobic fermentation of a carbohydrate substrate by a bacterium called Sphyngomonas elodea, previously called Pseudomonas elodea. It is a linear, anionic polymer of about 50,000 residues consisting of a tetrasaccharide repeating unit linked →4)L-rhamnopyranosyl-(␣-1→3)-D-glucopyranosyl-(␤-1→4)-D-glucuronopyranosyl-(␤-1→4)-D-glucopyranosyl-(␤-1→ with a substitution on the glucose unit following the rhamnose of L-glyceryl at C-2 and acetyl at C-6 (Chandrasekaran and Radha, 1995). Gellan gum may or may not be de-esterified by alkali treatment to produce the low acyl and high acyl grades. The functionality of gellan gum depends on the degree of acylation. High acyl gellan forms soft, very elastic, transparent, and flexible gels, while low acyl gellan forms hard, nonelastic brittle gels that are on either extreme of textural spectrum (Sworn, 2000a), the high acyl gellan being more flexible than the xanthan-LBG gel and being firmer and more brittle than the agar gel. Both grades produce thermoreversible gels. Gellan like carrageenan swells and thickens as the water is heating but loses this viscosity as the gum fully dissolves. Sworn (2000a) summarizes the other differences between low acyl and high acyl gellans such as: (1) full hydration of low acyl gellan takes place at 80–95◦ C for low acyl gellan; and 70◦ C or higher is sufficient for high acyl gellan; (2) low acyl gellan sets at 10–60◦ C depending on concentration and presence of ions, while high acyl gellan sets at 70–80◦ C, both grades showing no hysteresis; (3) gelling is improved with addition of acids and mono- and divalent ions with low acyl gellan, whereas the high acyl gellan is not affected by these ions; (4) sugar reduces firmness and modifies texture of low acyl gellan gels, but increases gel strength of high acyl gellan gels. Low acyl gellan is used more in jelly and fruit preparations because it produces a softer gel that is easier to spread. Low acyl gellan may be used in bakery or confectioners jelly with short, clean bite and flavor. In fruit preparations, low acyl gellan can also be used although usage would depend on the fruit and its ion content. Ca++ , Mg++ , Na+ , and K+ ions are all present in fruits at varying concentrations; hence, a

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fruit preparation optimized for one fruit will often need modification for another fruit using gellan gum. A fruit filling made with low acyl gellan gum combined with starch produced a glossy appearance, good flavor release, excellent stability at pH 3.4, and total soluble solids of 56% (Sworn, 2000a). Problems with Bakery Fillings Cracking Cracking is a problem often encountered in pumpkin pie where the inherent starch in the pumpkin and the added egg are the main binders. The problem is not fully understood. Since it happens only with unstabilized recipes, one theory is that the starch or the egg is not providing enough moisture barrier and the pie filling dries up to a great extent during the baking step. The result is a drier pie; and since starch has a weaker micelle structure than gum, it is not able to hold the solids together; and, therefore, the filling cracks. There are appreciable amounts of insoluble solids in the pumpkin puree that need to be bound together by the stabilizer. The addition of gums such as LBG and carrageenan could improve moisture retention of the pie filling and provides binding and structure to the product. As shown in Figure 5.1 the effect of the gum is dramatic in fixing this problem. The mechanism of how LBG and carrageenan work could be twofold. LBG thickens during baking, slows down heat transfer, binds water, and reduces evaporation loss. The carrageenan is also activated by heat but water binding happens when the product starts to cool forming a soft gel matrix that helps bind

Figure 5.1.

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the product. Other gums such as tara gum and methylcellulose could work the same way as LBG and the alginate as carrageenan to prevent cracking. However, too much water binding can also lead to cracking by forming a surface film that causes pressure to build within the pie resulting to an eruption and cracked surface. Boil Out Fruit fillings that have not been thickened sufficiently, either through a lack of thickeners used or improper cooking of the filling, will be thin and will tend to run and boil over during baking. That boil out not only spoils the appearance of the pies but it also makes the crust soggy from the juices. There are many reasons that have been postulated as to why a bakery filling would boil over, such as: 1. Baking temperature is too low or too high. Oven temperatures for baking pies are much higher than the boiling point of water. If length of baking is timed so that the filling does not reach boiling temperature, boil out will be eliminated. However, the end point of baking is usually based on the doneness of the crust, hence, there is much variability in the baking time and temperature used by bakers and processors. If baking temperature is too low, it will take too long for the crust to bake to the proper color relative to heating rate of the filling, hence, there is a greater chance that the filling will reach boiling temperature and spill. The pie filling should not start boiling before the top crust has developed the desired color and the pies can be removed from the oven. If the temperature too high, especially without a thickener, the filling could also reach boiling temperature and boil over. 2. Sugar content in the pie filling is too low. The amount of sugar in the filling affects its boiling point. A fruit pie filling with a low sugar content will boil faster than a filling with a high sugar content. 3. Absence of stabilizer. The only other reason why a bakery filling boils out is that it is not thick enough. Convection mode of heat transfer is more efficient than conduction; i.e., heat transfer is faster when filling is thinner and can reach boiling temperature and boil over. Filling ingredients, such as sugar, corn syrup, or oil/shortening, all thin out dramatically when heated. Thickening the filling with gums will slow down heat transfer.

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The choice of gum depends on how much initial thickening is required to hold the filling in place when the product is cold, and how much thickening is needed to prevent boil out when the product is hot. In addition to sugar or corn syrup used, the type of fruit used in the filling, the inherent pectin content of the fruit, and the acidity of the fruit determine how much thickening is needed. Because of their natural pectin content, apples will likely not run during baking without an additional gum thickener. Augmenting this thickening with gum such as more pectin, LBG, guar, konjac, and methyl cellulose is recommended. Peaches are juicier than most fruits used in fillings; hence, they would require more stabilizer. Cherries, especially the sour pitted variety used for pie filling, are more acidic and require a more sugar to sweeten the filling and would require a more acid tolerant thickener such as konjac and xanthan.

Shrinkage Turnovers often create a gap between the baked crust and the filling. Sometimes fruit pies also show a gap between the upper crust and the filling layer. In the case of turnovers, either the pastry dough expands too much or the filling shrinks, or both. In the case of fruit pies, shrinkage of the filling is the likely culprit. Shrinkage is a result of the filling drying too much. The fix could be as simple as preheating the oven so that the crust browns faster and the pie is baked quicker thereby minimizing moisture loss. The other solution is to use a stabilizer such as LBG, methylcellulose, or a cookup starch that would thicken the filling during baking, bind water, and reduce moisture loss. In conjunction, insoluble solids such as cellulose powder, fruit fiber, or even MCC could be used for bulk. Shrinkage of aerated cr`eme fillings is a problem that is due to partial collapse of the air structure and a costly one for bakers. More air retained by the filling means savings for the manufacturer because usage of aerated creams is based on volume more than weight. Cr`eme filling shrinks on standing and continues to shrink while in the pastry; hence, the pastry is overfilled initially to counter this defect. The use of foaming stabilizer such as PGA and hydroxypropyl cellulose promotes aeration and stabilization of the air structure. Either gum could be used at 0.15–0.20% in the cream recipe.

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Emulsion Separation Bakery fillings containing appreciable levels of fat such as custard and Bavarian cream are often reformulated to reduce cost. Egg provides emulsification from the yolk lecithin and also water binding from the albumen; however, reducing the egg or removing it require additional thickener and emulsifier. The use of a gum such as carrageenan and sodium alginate combined with emulsifier such as with mono- and diglycerides could stabilize this system. A gum emulsifier such as PGA could also provide the thickening and, hence, could be used to achieve both functions. Freeze-Thaw Stability Not many ingredients will survive the freezing process without losing all or some of their functionality. When water in the product freezes, the solutes such as sugar get concentrated, protein components denature, and starch components retrograde. The result is a destabilized system where the sugar is no longer uniformly distributed throughout the product, the protein losing water binding and emulsifying property, and starch reverting to insoluble state. Without stabilizer, the thawed product could be watery and have lost integrity and structure, or it could have fat that totally separated. Traditional starches normally retrograde when frozen. Gums, however, are mostly freeze-thaw stable and are more functional in frozen fillings, and so are some grades of modified food starch. Cold-water soluble gums such as guar, konjac gum, xanthan, CMC, methyl cellulose, and alginates could be used in frozen fillings and filled pies to impart freeze-thaw stability and water binding on thawing and/or rebaking of the product. Sogginess of the Pastry Sogginess of the crust is the most annoying problem with baked pies, turnovers, and strudels when they sit a day or longer after baking. These products are best consumed fresh from the oven; because with time, the crust will get soggy and unappetizing. The crust will always be drier and lower in aw than the fruit filling, and there is really no solution to

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this problem but to delay the moisture migration so that the pastry stays fresh longer. The following recommendations are given as options: 1. Moisture proof the bottom of the crust before chilling and filling. Brush melted butter on the bottom of the crust and refrigerate for about 15 minutes so it sets before depositing the filling. 2. Stabilize the filling to immobilize water when filling is cold and when cooked. Again, LBG, methyl cellulose, tara gum, and cook-up starches will provide thickening during baking; and gelling agents such as pectin, gellan, agar, and alginates can provide a set to the filling that could slow down moisture migration in a two-phase food such as pies and turnovers.

Research Need Bakery fillings are generally high calorie foods with high glycemic index because of their high sugar and starch levels, although a few types such as the cr`eme fillings are calorie-dense due to high fat content. Formulating a new breed of low glycemic foods and foods high in insoluble and soluble dietary fibers is a research thrust that should extend to the bakery fillings. Unlike the Atkins diet, the new recipes will replace traditional carbohydrates such as sugars, starches, and dextrins with other carbohydrates that are not digested and metabolized by humans, such as gum polysaccharides. Several hydrocolloids can replace sugar and dextrins; these include gum arabic, inulin, resistant maltodextrins, and polydextrose. All these gums have very low viscosities and can dissolve in water at high concentrations [50–80% w/w] like sugar, dextrose, and corn syrup. Unlike traditional carbohydrates, these ingredients are not digested in the stomach and are passed on to the large intestine acting as prebiotic for the gut flora. They are not metabolized into glucose and are not absorbed in to the body and, therefore, and have very low to zero glycemic indices. The starch, on the other hand, can be replaced with gum combinations that closely mimic its texture. The resulting formulations, therefore, are very low in sugar and starch with reduced caloric value, high in soluble fiber that could reduce blood cholesterol and have low glycemic index, which are good for diabetics and for obesity control.

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References Chandrasekaran R. and Radha A. 1995. Molecular architectures and functional properties of gellan gum and related polysaccharides. Trends Food Sci, 6:143–148. Donati I., Holtan S., Mørch Y.A., Borgogna M., Dentini M., and Skj˚ak-Bræk. 2005. New hypothesis on the role of alternating sequences in calcium-alginate gels. Biomacromolecules, 6:1031–1040. Dorner H. and Tessmer E. 1953. Thickening agents. Brot Gebaeck, 7:163. Draget K.I. 2000. Alginates. In: Handbook of Hydrocolloids, Phillips G.O. and Williams P.A., editors. CRC Press/Woodhead Publishing: Boca Raton FL & Cambridge, UK, pp. 379–393. Falshaw R., Bixler H.J., and Johndro K. 2001. Structure and performance of commercial kappa-2 carrageenan extracts I. Structure analysis. Food Hydrocolloids, 15:441–452. Giannouli P. and Morris E.R. 2003. Cryogelation of xanthan. Food Hydrocolloids, 17:495–501. Goycoolea F.M., Milas M., and Rinaudo M. 2001. Associative phenomena in galactomannan-deacetylated xanthan systems. Int J Biol Macromol, 29:181–192. Iijima H. and Takeo K. 2000. Microcrystalline cellulose: an overview. In: Handbook of Hydrocolloids, Phillips G.O. and Williams P.A., editors. CRC Press/Woodhead Publishing: Boca Raton, FL & Cambridge, UK, pp. 331–346. Jansson P.E., Keene L., and Lindberg B. 1975. Structure of the exocellular polysaccharide from Xanthomonas campestris. Carbohydr Res, 45:275–282. Kato K. and Matsuda K. 1973. Isolation of oligosaccharides corresponding to the branching-point of konjac mannan. Agric Biol Chem, 37(9):2045–2051. Kato K., Watanabe T., and Matsuda K. 1969. Studies of the chemical structure of konjac mannan: I. Isolation and characterization of oligosaccharides from the partial hydrolyzate of the mannan. Agr Biol Chem, 33(10):1446–1453. Kato K., Watanabe T., and Matsuda K. 1970. Studies of the chemical structure of konjac mannan: II. Isolation and characterization of oligosaccharides from the enzymatic hydrolyzate of the mannan. Agr Biol Chem, 34(4):532–539. Kunz C.E. and Robinson W.B. 1962. Hydrophilic colloids in fruit pie fillings. Food Technol, 16(7):100–102. Labropoulos K.C., Niesz D.E., Danforth S.C., and Kevrekidis P.G. 2002. Dynamic rheology of agar gels: theory and experiment. Part I. Development of a rheological model. Carbohydr Polym, 50:393–406. Lootens D., Capel F., Durand D., Nicolai T., Boulenguer P., and Langendorff V. 2003. Influence of pH, Ca concentration, temperature and amidation on the gelation of low methoxyl pectin. Food Hydrocolloids, 17:237–244. Maekaji K. 1974. The mechanism of gelation of konjac mannan. Agric Biol Chem, 38(2):315–321. Maekaji K. 1978. Nippon Nogeikagakukaishi, 52(251):485, 513. Melton L.D., Mindt L., Rees D.A., and Sanderson G.R. 1976. Covalent structure of the polysaccharide from Xanthomonas campestris: Evidence from partial hydrolysis studies. Carbohydr Res, 46:245–257.

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Murray J.C.F. 2000. Cellulosics. In: Handbook of Hydrocolloids, Phillips G.O. and Williams P.A., editors. CRC Press/Woodhead Publishing: Boca Raton, FL & Cambridge, UK, pp. 219–229. P´erez S., Mazeau K. and Herv´e du Penhoat C. 2000. The three-dimensional structures of the pectic polysaccharides. Plant Physiol Biochem, 38:37–55. P´erez S., Rodr´ıguez-Carvajal M.A., and Doco T. 2003. A complex plant cell wall polysaccharide: rhamnogalacturonan II. A structure in quest of a function. Biochimie, 85:109–121. Petkowicz C.L.O., Reicher F., and Mazeau K. 1998. Conformational analysis of galactomannans: From oligomeric segments to polymeric chains. Carbohydr Polym, 37:25–39. Ralet M.C., Dronnet V., Buchholt H.C., and Thibault J.F. 2001. Enzymatically and chemically de-esterified lime pectins: characterisation, polyelectrolyte behaviour and calcium binding properties. Carbohydr Res, 336:117–125. Shimahara H., Suzuki H., Sugiyama N., and Nishizawa K. 1975a. Isolation and characterization of oligosaccharides from an enzymic hydrolysate of konjac glucomannan. Agric Biol Chem, 39(2):293–299. Shimahara H., Suzuki H., Sugiyama N., and Nishizawa K. 1975b. Partial purification of ß-mannanases from the konjac tubers and their substrate specificity in relation to the structure of konjac glucomannan. Agric Biol Chem, 39(2):301–312. Strachan C.C., Moyls A.W., and Atkinson F.E. 1960. Commercial canning of fruit pie fillings. Can Dept Agric Publ, 1062. Sugiyama N., Shimahara H., Andoh T., Takemoto M., and Kamata T. 1972. Molecular weights of konjac mannans of various sources. Agric Biol Chem, 36(8):1381–1387. Sworn G. 2000a. Gellan gums. In: Handbook of Hydrocolloids, Phillips G.O. and Williams P.A., editors. CRC Press/Woodhead Publishing: Boca Raton, FL & Cambridge, UK, pp. 117–135. Sworn G. 2000b. Xanthan gum. In: Handbook of Hydrocolloids, Phillips G.O. and Williams P.A., editors. CRC Press/Woodhead Publishing: Boca Raton, FL & Cambridge, UK, pp. 103–116. Takigami S. 2000. Konjac mannan. In: Handbook of Hydrocolloids, Phillips G.O. and Williams P.A., editors. CRC Press/Woodhead Publishing: Boca Raton, FL & Cambridge, UK, pp. 413–424. Welinga W.C. 2000. Galactomannans. In: Handbook of Hydrocolloids, Phillips G.O. and Williams P.A., editors. CRC Press/Woodhead Publishing: Boca Raton, FL & Cambridge, UK, pp. 137–154.

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Chapter 6 Hydrocolloids in Frozen Dairy Desserts Philip A. Rakes and Thomas R. Laaman

Frozen dessert manufacturers in their wisdom, nearly universally employ hydrocolloids as key ingredients to make ice creams and other frozen desserts. This chapter explains why and how these key ingredients are utilized in this highly complex food system. In order to adequately explain the utilization of hydrocolloids, a complete in-depth discussion of frozen dessert ingredients, formulation, and processing is presented. In this way, the reader will feel confident to fully approach the making of ice cream and its many modern variations and related products. Before undertaking the breadth of this assignment, let us turn our attention briefly to the role of hydrocolloids in frozen desserts. Firstly, hydrocolloids are generally called stabilizers in the frozen dessert industry and are usually sold in blends with emulsifiers. This class of ingredients, stabilizers/emulsifiers, used in most frozen dessert formulations in usually relatively small amounts (i.e., <1%) has important functions to serve, disproportionate to their use level. The bifurcated name indicates the duality of their functions, yet they are often combined together for economic, technical, and practical reasons discussed later in this chapter. Whether combined or not, their functionalities must be balanced against each other and against of other ingredients (i.e., proteins, fats, unbound minerals, lower molecular weight

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carbohydrates). The entire process for making frozen desserts can typically be summarized as making a water suspension of solutes or an oil in water emulsion that sometimes has a third phase of air added prior to or during freezing of the whole formulation. Inappropriate choices in this part of the ingredient declaration can cause product handling problems (i.e., mix separation, mix gelation, etc.) and finished product defects (i.e., poor and/or inconsistent overrun incorporation, wet/sloppy nonextrudable product, iciness, shrinkage, etc.). Any frozen dessert formula has varying degrees of solutes (i.e., sugars, water, amino acids, salts, etc.) and suspended colloids and fats that are in multiple physical states (i.e., liquid, crystalline, glass) at any one point in time. It is the relative ratios of these physical states and the transitions (e.g., aging/fat crystallization, melting, freezing) between them, which often determine the performance of a frozen dessert formulation in a given set of processing and storage/distribution conditions. Stabilizer and emulsifier ingredients often serve to modulate these transitions in beneficial ways. The stabilizer portion is primarily responsible for limiting the mobility of the water in a formulation. Pound for pound the hydrocolloids/ gums that usually comprise this portion bind or limit the mobility of the water the most when compared with the other ingredients. Limiting the mobility of unfrozen water in frozen desserts is important and often critical to the acceptable shelf life of hardpack frozen products. There is almost always some unfrozen water (i.e., 5–20%) in a frozen dessert formulation regardless of whether the hardpack products are stored at temperatures below −20◦ F or not. This water, which is in the glass state and not in the crystalline state, represents a potential threat to the shelf life (i.e., iciness from larger ice crystals, sandiness from larger lactose crystals, etc.) of hardpack frozen desserts, when they undergo temperature fluctuations during storage and distribution. Each degree increase in temperature during storage and distribution induces a roughly proportional amount of melting in the product, which upon refreezing tends to produce larger and larger ice crystals. This increase occurs because the refreezing usually occurs at a much slower rate than the initial process freezing (i.e., many minutes or hours vs. seconds). It has been postulated (Schenz 1994) that hydrocolloids “stabilize” ice crystal size primarily by increasing the viscosity of the rubbery water phase that occurs with increasing volume during heat shock events;

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which in turn inhibits the diffusional mobility of “free water” (i.e., noncrystalline and nonglassy) and its solutes above the glass transition temperature. The desired limitations on water mobility ostensibly manifest themselves by increasing the viscosity of the mix and its stability against phase separations. Additionally, the limitations on water mobility show themselves in the finished frozen product by enhancing the body and texture, retarding the ice crystal growth, improving the meltdown performance, and tangentially helping support the incorporation of air into the mix with the emulsifying ingredients present in the formula. There are some hydrocolloids that are used for their ability to interact with proteins to form gels or thick suspensions, or to inhibit serum separation (i.e., carrageenan). Others like guar gum, locust bean gum, xanthan gum, tara gum, cellulose gum, microcrystalline cellulose, etc. are used to control water mobility and provide certain finished product body characteristics (i.e., guar can be used to provide chewiness). Gelatin gives different characteristics and in some formulations may assist with air incorporation. Algin-based stabilizers provide yet another different body characteristic. All hydrocolloids in a combined stabilizer system must be balanced out at an acceptable total use level in a frozen dessert formulation to prevent mix gelation and separation due to interactions with each other (i.e., xanthan with locust bean gum, carrageenan with locust bean gum, etc.) and other formula constituents (i.e., algin with free calcium sources). The emulsifier portion primarily is responsible for interacting with the lipid portion of a frozen dessert formulation. The benefits of the emulsifier largely arise from the fact that it partially changes place with the proteins at the fat/water interface during refrigerated aging of the mix in dairy based formulations (Goff 2005). Nondairy formulations may work in a similar manner but this assumption has not been confirmed widely in the publicly disclosed technical literature. This partial interchange makes the fat somewhat easier to partially agglomerate during the freezing and whipping processes, which in turn makes for easier air incorporation and better air retention or lack of shrinkage in finished hardpack products and a stiffer and dryer body upon extrusion from the barrel freezer. Also, the appropriate use of emulsifiers improves the smoothness of texture and meltdown performance of finished hardpack products. The stability or resistance to phase separation

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of the frozen dessert mix prior to freezing can also be enhanced by the use of emulsifiers. Recent research (Hopkinson 2006) has indicated that the hydrophilic part of an emulsifier can have a potentially significant effect on the size of ice crystals formed in a frozen dessert if properly selected for type and use level. This is a subject area under some debate and still under study in the academic community (Hartel 2006). Table 6.1 contains a list of typical ingredients that can be used for stabilization and emulsification of frozen desserts together with a range of use levels for each ingredient. Within these ranges, the product developer will choose the specific use level based on the other ingredients in the formulation, the complexity of the processing and the freezing that the formulation will be subjected to, and the final storage stability requirements. These variables will be discussed at greater lengths below, and specific stabilizer levels will be suggested for various formulation types. The following are representative relative levels of each hydrocolloid and emulsifier in various categories of stabilizer blends. A very popular type of frozen dessert stabilizer is known as galactomannan-based, because the two main ingredients in terms of total amounts, guar gum and locust bean gum, are both carbohydrate polymers composed of galactose and mannose. A galactomannan-based stabilizer/emulsifier system may have a stabilizer blend composition like the following: guar gum (30–50%), locust bean gum (10–30%), carrageenan (3–10%), mono- and diglycerides (10–57%), while a cellulose-based stabilizer/emulsifier system may have a composition like the following: microcrystalline cellulose (45–65%), cellulose gum (5–15%), guar gum (3–5%), mono- and diglycerides (15–47%) used at twice the total use level for the system as that for the galactomannan-based product. In some cases, a stabilizer system may contain a sizable amount of both guar gum and cellulosics such as the following: microcrystalline cellulose (20–30%), cellulose gum (5%), guar gum (15–25%), carrageenan (1–10%), and mono- and diglycerides (30–40%). Other examples of stabilizer/emulsifier breakdowns are also mentioned briefly in the context of specific formulations in Tables 6.2–6.7 later in the chapter. Irrespective of the specific stabilizer/emulsifier ingredients chosen, they must also be compatible with other protein, fat, and carbohydrate ingredients in the formulation in terms of suspension stability (i.e., separation/sedimentation issues) and mix viscosity (i.e., gelation issues) for a given set of processing conditions. Additionally, selection and use

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Table 6.1. Typical use levels for selected hydrocolloids and emulsifiers.

Name

Source

Use Level Range (%)

Guar gum Locust bean gum Carrageenan Xanthan gum Algins Cellulose gum Cellulose gel Gelatin Pectin Mono- and diglycerides Lactic acid esters of monoand diglycerides Citric acid esters of monoand diglycerides Acetylated monoglycerides Diacetyl tartaric acid esters of monoglycerides Succinic acid esters of monoglycerides Sodium stearoyl lactylate Calcium stearoyl lactylate Polysorbate 60 Polysorbate 65 Polysorbate 80 Propylene glycol esters of monoglycerides Polyglycerol esters of monoglycerides Glycerol monostearate Propylene glycol monostearate Soy lecithin Egg lecithin

Plant Plant Seaweed Microbial Kelp Plant or microbial Plant or microbial Animal Plant Vegetable oil Vegetable oil, lactic acid

0.03–0.60 0.03–0.60 0.01–0.10 0.02–0.80 0.10–1.00 0.05–0.50 0.10–1.00 0.10–1.00 0.05–1.00 0.05–0.50 0.05–0.50

Vegetable oil, citric acid

0.05–0.50

Vegetable oil, acetic acid Vegetable oil, tartaric acid, acetic acid Vegetable oil, succinic acid

0.05–0.50 0.05–0.50

Synthetic Synthetic Synthetic Synthetic Synthetic Vegetable oil, propylene glycol Vegetable oil, glycerin

0.05–0.50 0.05–0.50 0.01–0.10 0.01–0.10 0.01–0.10 0.01–1.00

Synthetic Synthetic

0.01–1.00 0.01–1.00

Plant Animal

0.10–1.00 0.10–1.00

0.05–0.50

0.01–1.00

level of emulsifiers (e.g., Polysorbate 80) and some gums (e.g., gum acacia) can have significant effects on the ability of a frozen dessert mix to incorporate air (i.e., maximum overrun level) and hold it in sufficient quantities for a sufficient period of time (i.e., resistance to shrinkage). Overuse of emulsifiers can have consequences (i.e., too much Poly

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80 [0.06% or higher] gives a bitter flavor and buttering off defect) as well. These individual ingredients can be purchased and sourced by the finished frozen dessert manufacturer; or they can be purchased and sourced as combined stabilizer/emulsifier systems, as is often the case for many ice cream factories. The former option gives the manufacturer maximum control and flexibility but incurs maximum complexity and responsibility for the quality control and quality assurance functions of the manufacturer. The components of the combined stabilizer/emulsifier systems are sometimes subject to price and supply fluctuations that can be challenging to manage, especially for finished frozen food manufacturers who purchase them in relatively small (i.e., less than truckload, less than pallet) quantities. Also, there can be quality variations that accompany these spikes in supply that require experience and a significant amount of raw material testing (i.e., viscosity, hydration times, solubility levels, residual enzyme activities, etc.) and blending to manage one’s way through a crisis. In general, multicomponent systems that are balanced and standardized around relatively specific applications (i.e., hardpack frozen desserts, soft serve, milkshakes, etc.) tend to fair better in the long run with respect to stability of price and supply, since limitations with any one ingredient are likely to be diluted and extended by the other ingredients. As well, the ingredient system supplier can focus a lot of time and energy on resolving problems with these low inclusion level ingredients while the finished food manufacturer often has other competing priorities (i.e., major ingredients at high inclusion levels and finished product delivery issues, etc.) to dominate his time and energy. This chapter is meant as a practical and elementary guide to formulation and stabilization of frozen desserts. For purposes of discussion in this text, we refer to any product conforming to the standard of identity described in 21 CFR 135 as “ice cream” or as appropriate other names (i.e., sherbet, water ice, etc.) for use in the United States. Any product outside these specific standards will be referred to as a “frozen dessert” with any appropriate modifiers (i.e., nondairy, soy, rice, etc.). There are other standards of identity for products called ice cream in other countries (e.g., Canada); and indeed in some states and provinces this should be given proper attention, as dictated by the distribution of the product. One can obtain these documents by searching the appropriate government websites.

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It is important from the outset of any product development effort to establish where the aforementioned standards apply, so that one can begin the process of defining the ingredient-use limitations. Subsequently, the product developer needs to arrive at the precise final product presentation format (i.e., soft serve vs. hardpack, bulk dipped vs. consumer package, portion controlled novelty vs. home consumer dipped package). Having arrived at these conclusions, the product developer will have the ability to begin to understand the mix production, freezing, packaging, and distribution conditions that must intersect acceptably with the organoleptic targets set by Marketing. Formula Descriptors Before the product developer begins choosing specific ingredients to insert into a formulation, it is often useful to review the major relevant characterizing formula variables and their definitions. The use of formula descriptors expands upon a standard recipe (i.e., list of ingredients with amounts used) for a product to give it broader definition and meaning, which permits subsequent comparison with other recipes for similar products and even different frozen dessert products. Accurate characterization of a recipe into a general formula with descriptors or macroscopic characterizing variables also allows the possibility of formulating essentially the same or similar frozen dessert products from different ingredient sources. The formula descriptors can include basic compositional variables like fat, protein, minerals/ ash, and carbohydrates and/or generic indexes like milk solids, whey solids, and soy solids as well as physical parameters like freezing point. Subsequently the ingredients chosen and their impact on these variables must be identified and quantified. This process can be accomplished with pen, paper, and calculator or with several different computer spreadsheet programs on the market (i.e., Owl Software, Genesis R&D, etc.). Some of the mostly used macroscopic formula characterizing variables for ice cream and frozen desserts can be summarized and defined as follows: Fat%—Sum of all fat/lipid percentages contained in the formula ingredients; often useful to know if the fat is emulsified or free.

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MSNF or NMS%—(Milk solids not fat) or (nonfat milk solids) is the sum of all milk-derived solids percentages minus any fat%. Often necessary and useful to know is the protein, ash, and lactose ratios of these solids as well as the form of the proteins (i.e., casein vs. whey ratios, heat denaturation level, pH level, fractionation levels, hydrolysis levels, microparticulation levels, ionic environment). Nonfat milk solids that come directly from milk without any significant alteration (other than heat of pasteurization) or fractionation are sometimes referred to as natural serum solids. Whey solids%—The sum of all milk-derived solids percentages deriving from cheese whey or microfiltration whey. It is important for standard of identity ice cream compliance determination (i.e., 25% or less of MSNF). In the past, these solids were sometimes referred to as lactalbumin or serum solids. These do not include whey protein present in nonfat milk solids. Total whey protein and casein protein can be useful to monitor for formulation purposes as well. Milk solids%—The sum of all milk-derived solids percentages, this is important for standard of identity ice cream compliance determination (i.e., minimum 20% milk solids for full-fat ice cream). The lactose% derived from these milk solids can be important to monitor for formulation efficacy purposes (i.e., avoidance of sandiness). Natural serum solids%—The sum of all milk-derived solids percentages minus the percentage of fat and the percentage of any whey solids. The casein to whey protein ratio is usually 80:20. See above comments on MSNF%. (DeYoung 1989). Total solids%—The sum of all ingredient solids percentages in a formulation. This is relevant and useful for standards of identity compliance issues and other formulation balancing concerns. Freezing point—The temperature at which a given mix composition begins to form ice crystals upon cooling. Freezing point depression is the difference in temperature between 0◦ C (32◦ F) and the point at which the mix begins to freeze (i.e., form detectable ice crystals). This value is dependent upon the level of dissolved solids and their various molecular weights. This sort of data can be measured for an ingredient with a cryoscope and is sometimes given out by the supplier. Data is also available in the technical literature (Smith and Bradley 1983; Baer and Baldwin 1984). Sucrose equivalence—This is a numerical index of the relative amount of freezing point depression given by an ingredient in comparison

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to sucrose. Calculated as the ratio of the sucrose molecular weight over the molecular weight of the ingredient in question, it is multiplied by the percentage of the ingredient to arrive at its relative contribution to the total freezing point depression of the mix formulation. It is often used with the said values of the other ingredients to calculate a total overall estimated freezing point for a given mix composition. It is important to realize that the sucrose equivalence (i.e., freezing point depression index) for some ingredients can change due to heat treatment (decrease due to polymerization, e.g., whey protein or increase due to degradation, e.g., sugar inversion), enzyme hydrolysis (e.g., lactose hydrolysis and different dextrose equivalent maltodextrins and syrups), and pH changes (e.g., sodium release from sodium citrate and calcium release from micellar casein). Therefore it is important to consider the mix environment (i.e., pH, total solids or in aqueous phase concentration, temperature and actual molecular weights of the ingredients) when assigning sucrose equivalence values to different ingredients for freezing point depression calculations. These differences can be important, if not critical, in determining the freezing performance of a particular product formulation. Suppliers of sugars, polyols, bulk sweetening syrups, corn syrups, soluble fibers, hydrolyzed proteins, etc. will sometimes supply this information about their ingredients or will give out the molecular weight information necessary for the calculation of an estimated sucrose equivalence value. Free fat%—This is a wet lab technique involving solvent extraction for determining the amount of fat that is de-emulsified during the freezing and whipping processes that take place during production. It can serve as a rough numerical index of the performance of a particular freezing process or for particular freezing equipment or for a particular mix within a given, well-defined, and consistent freezing process (assuming a given set of equipment). %Destabilization—This is a technique that has gained some favor over the free-fat method. It is a spectroscopic method for measuring the amount of fat destabilization that occurs in an ice cream mix (Marschall et al. 2003). It relies upon measuring a difference in absorbance of diluted and centrifuged frozen dessert mixes (unfrozen mix and melted frozen dessert). Aggregated fat globules absorb light differently than smaller, more dispersed fat globules; and hence a

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difference can be measured that relates to the processing of the mix. Experience has shown that in some cases the destabilization level for a mix going into an ice cream sandwich could be three times the level of another ice cream mix going into pints (Marschall and Arbuckle 1996). Solid fat index—Ratio of crystalline fat to noncrystalline fat in an ingredient or a mix formulation. It is a useful index that can relate to relative hardness of a frozen dessert in a defined temperature range. It can also, in some formulations, have effects on the mix aging time, its final viscosity, and its ability to build stable air cells during the freezing/whipping process. Relative sweetness—A numerical index of a sensory comparison of sweet taste sensation against a solution of sucrose. Sucrose is arbitrarily assigned a score of 100. Solutions of ingredients are made up and tested against sucrose solution controls and assigned a score afterward. Overrun%—This is a numerical index of the amount of air that is whipped into a product’s mix. It is calculated with the following equation: Overrun % = (100) ×

[weight of mix for fixed volume]–[weight of finished product for fixed volume] [weight of finished product for fixed volume]

an alternative formula would be: Overrrun % = (100) [volume of frozen dessert]–[volume of frozen dessert mix] × [volume of frozen dessert mix] This characteristic can also be monitored by measuring the bulk density of the finished product. There are calibrated cups for this purpose as well that are often used by soft serve ice cream retailers. Soy solids not fat%—(SySNF) can be used to describe anything from defatted soy flour solids to defatted soy protein isolate solids including defatted soymilk solids, defatted soy protein concentrate solids, and defatted soy fiber solids. The number assigned to a particular formula would be the sum of all these defatted soy solids percentages from all the ingredients in a formula, be it nondairy or mixed.

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Total soy solids%—(TSyS) can be used to quantify all the soy-sourced solids in a formula or in other words SySNF plus any soybean oil that comes with the solids sources or is added additionally to the formula. This number along with SySNF could be useful for any future standards concerning soy frozen desserts. For formulation purposes, it will also be important to monitor the soy protein level, especially versus other protein sources. Issues of fiber, sugars, and other carbohydrates (i.e., raffinose and stachyose) can be monitored to some degree by virtue of the testing required for NLEA panel compliance. Mix viscosity (centipoise [cP])—This is a rheological term that is a measure of the resistance to flow or more generically the thickness of a frozen dessert mix prior to freezing. It has significant implications for mix processing system choices, including pasteurization and mix handling just prior to entry into the freezing process. It sometimes, but not always, bears some correlation with mix stability issues (i.e., tendency toward separation with storage time) and finished product texture. Compositional testing of the ingredients is necessary to assemble the finished product formula with the targeted labeling (i.e., ingredient declaration, NLEA nutritional panel). This information, in the hands of a knowledgeable product developer, will also help to guide the formulation toward the performance variables required for the finished product.

Formula Development Other nondairy sources of protein, fat, and carbohydrates can use similar indices for compliance issues or for formulation monitoring purposes. Many of these same variables can be used to help characterize entire formulations with respect to sweetness and freezing performance variables. These macroscopic characterizations can be useful in the beginning stages of product development for comparison to other proposed formulas and existing formulas with known performance histories and organoleptic characteristics. Such comparisons can be useful when the developer is trying to narrow down the number of formula variable

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combinations to be physically tested in the plant or pilot plant. These comparisons can also be useful in deciding on a mix-making process and a freezing process in the beginning stages of product development. An example of a useful comparison would be where someone is trying to take a soft serve frozen dessert formulation and put it into a hardpack format and hoping to get the same texture. Consideration of the sucrose equivalence data would show that to be a difficult task that would require significant changes in formulation if not in the freezing process as well. The ratio of the frozen to unfrozen water in a frozen dessert under a given set of freezing, storage, and serving conditions can be critical to achieving the proper level of stiffness for packaging, meltdown resistance, and textural qualities, as would be expected. However, this ratio under a given set of serving conditions can also affect the relative perception of coldness/warmness in the product and possibly can have some impact on flavor release. So, a good soft serve formula might take on a colder and icier perception when consumed as a hardpack product since there is more ice to be melted (assuming lower solids and more ice formed in the hardening process) in the mouth upon consumption (assuming the sucrose equivalence is lower); and if the solids are lower and the overrun is higher, the body and texture may be perceived as weak. Other performance variables in the finished product (i.e., stiffness, elasticity, scoopability, etc.) can be measured by the product developer as needed by using sensory panels and/or instrumentation (i.e., Instron, Advanced MicroSystems TA—XT, etc.). Shelf-life issues can also be monitored via heat shock testing with monitoring by the product developer and/or a sensory panel for shrinkage, iciness defect, sandy/grainy defect, loss of flavor, and loss of color. Ultimately, some combination of this finished product testing is required to know if the product developer has hit their assigned target.

Formula Examples Tables 6.2–6.7 that follow show a sampling of frozen dessert formulas with different stabilizers at different use levels. The tables show how the formulas are balanced with respect to macroscopic composition and performance variables. This task of balancing ingredients can be accomplished with pencil/paper and calculator or via computer

30.411 5.167 48.872 15.0 0.30 0.25 100.00

Cream NFDM Skim milk Sucrose MD Stabilizer Total

11.86 0.052 0.088 0.00 0.30 0.00 12.30

TF 13.533 4.971 4.496 14.985 0.30 0.232 38.52

TS 1.673 4.919 4.408 0.00 0.00 0.00 11.00

MSNF 1.673 4.919 4.408 0.00 0.00 0.00 11.00

NSS 0.00 0.00 0.000 0.00 0.00 0.00 0.00

WS 13.533 4.971 4.496 0.00 0.00 0.00 23.00

MS 11.860 0.052 0.088 0.00 0.00 0.00 12.00

MF

0.585 1.809 1.667 0.002 0.00 0.002 4.06

Prot

0.118 0.373 0.379 14.985 0.00 0.00 15.86

RS

0.867 2.682 2.370 14.985 0.00 0.00 20.90

SE

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TF, total fat; TS, total solids; MSNF, milk solids not fat (or NMS); NSS, natural serum solids; WS, whey solids; MS, total milk solids; MF, milk fat; Prot, protein; RS, relative sweetness; SE, sucrose equivalence; NFDM, nonfat dry milk; MD, mono- and diglycerides.

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Ingredient

Table 6.2. Twelve percent–fat ice cream with sodium alginate stabilizer.

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122 25.269 5.181 51.860 12.012 5.128 0.30 0.25 100.00

Cream NFDM Skim milk Sucrose Corn syrup MD Stabilizer Total

9.855 0.052 0.093 0.00 0.00 0.30 0.00 10.30

TF 11.245 4.984 4.771 12.00 5.000 0.30 0.241 38.54

TS 1.390 4.932 4.678 0.000 0.00 0.000 0.00 11.00

MSNF 1.390 4.932 4.678 0.00 0.00 0.00 0.00 11.00

NSS 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

WS 11.245 4.984 4.771 0.00 0.00 0.000 0.00 21.00

MS 9.855 0.052 0.093 0.00 0.00 0.000 0.00 10.00

MF 0.486 1.813 1.768 0.001 0.002 0.00 0.00 4.07

Prot

0.098 0.374 0.402 12.00 2.256 0.00 0.00 15.13

RS

0.72 2.689 2.515 12.00 3.625 0.00 0.00 21.55

SE

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TF, total fat; TS, total solids; MSNF, milk solids not fat (or NMS); NSS, natural serum solids; WS, whey solids; MS, total milk solids; MF, milk fat; Prot, protein; RS, relative sweetness; SE, sucrose equivalence; NFDM, nonfat dry milk; MD, mono- and diglycerides; MCC/CMC, microcrystalline cellulose, cellulose gum. Note: Stabilizer = microcrystalline cellulose (65–75%), cellulose gum (20–30%), carrageenan (5–20%).

%

Ingredient

Table 6.3. Ten percent–fat ice cream with MCC/CMC stabilizer with carrageenan.

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1.82 0.091 0.012 0.042 0.0 0.0 0.045 0.123 0.0 2.13

TF 2.049 10.351 1.154 1.158 11.489 4.48 2.300 0.318 0.0 33.30

TS 0.229 10.26 1.142 1.122 0.00 0.0 2.255 0.0 0.0 15.01

MSNF 0.229 10.26 1.142 0.0 0.00 0.0 2.255 0.00 0.0 13.85

NSS 0.00 0.00 0.0 1.158 0.00 0.0 0.00 0.00 0.0 1.16

WS 2.049 10.351 1.154 1.158 0.00 0.0 2.300 0.00 0.0 17.01

MS 1.82 0.091 0.012 0.042 0.00 0.0 0.045 0.00 0.0 2.01

MF 0.089 3.831 0.42 0.408 0.001 0.002 0.853 0.009 0.0 5.61

Prot

0.019 0.9 0.087 0.089 11.489 2.016 0.194 0.00 0.0 14.79

RS

0.121 5.638 0.623 0.601 11.489 3.248 1.213 0.00 0.0 22.93

SE

11:3

TF, total fat; TS, total solids; MSNF, milk solids not fat (or NMS); NSS, natural serum solids; WS, whey solids; MS, total milk solids; MF, milk fat; Prot, protein; RS, relative sweetness; SE, sucrose equivalence; NFDM, nonfat dry milk. Note: Stabilizer/emulsifier = mono- and diglycerides (20–40%), guar gum/xanthan gum/carrageenan (60–80%).

4.55 30.88 1.2 1.2 11.5 5.6 25.0 0.34 19.73 100.00

%

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Cream Condensed skim NFDM Whey protein concentrate Sucrose Corn syrup Cultured skim milk Stabilizer/Emulsifier Water Total

Ingredient

Table 6.4. Two percent–fat soft serve frozen yogurt (Galactomannan stabilizer with emulsifier).

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124 13.297 3.694 50.702 9.838 2.00 3.50 2.00 0.606 0.25 9.10 0.013 5.00 100.00

% 5.319 0.123 0.00 0.098 0.06 0.00 0.00 0.00 0.09 0.009 0.00 0.00 5.70

TF 5.989 0.444 0.00 9.464 1.92 3.493 1.98 0.604 0.234 8.554 0.013 4.905 37.60

TS 0.67 0.320 0.00 9.366 1.86 0.00 0.00 0.00 0.00 0.00 0.00 0.00 12.22

MSNF 0.67 0.320 0.00 9.366 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 10.3

NSS 0.00 0.00 0.00 0.00 1.92 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.92

WS 5.989 0.444 0.00 9.464 1.92 0.00 0.00 0.00 0.00 0.00 0.00 0.00 17.82

MS 5.319 0.123 0.00 0.098 0.06 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.60

MF 0.26 0.122 0.00 3.443 0.66 0.000 0.00 0.000 0.006 0.009 0.00 0.00 4.50

Prot

0.057 0.028 0.00 0.710 0.308 3.150 0.99 0.485 0.000 1.911 7.762 0.00 15.40

RS

0.353 0.172 0.00 5.106 1.296 3.465 3.76 2.242 0.00 3.094 0.011 2.500 22.00

SE

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TF, total fat; TS, total solids; MSNF, milk solids not fat (or NMS); NSS, natural serum solids; WS, whey solids; MS, total milk solids; MF, milk fat; Prot, protein; RS, relative sweetness; SE, sucrose equivalence; NFDM, nonfat dry milk; WPC HL, whey protein concentrate with partially hydrolyzed lactose. Note: Stabilizer/Emulsifier = mono- and diglycerides (20–60%), locust bean gum/guar gum/carrageenan (40–80%).

Cream Milk Water NFDM WPC HL Maltitol Sorbitol Glycerin Stabilizer/Emulsifier Maltodextrin 18 DE Sucralose Polydextrose Total

Ingredient

Table 6.5. 5.71%-fat, no-sugar-added light ice cream (Galactomannan stabilizer with emulsifier).

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11.932 0.00 0.056 0.00 0.00 0.00 0.19 0.072 0.00 0.00 0.00 12.25

TF 13.435 0.00 5.343 2.910 3.992 2.847 1.900 0.187 1.900 0.019 5.467 38.00

TS 1.503 0.00 5.287 0.00 0.00 0.00 1.710 0.00 0.00 0.00 0.00 8.50

MSNF 0.793 0.00 2.832 0.288 0.00 0.008 0.120 0.00 0.10 0.00 0.451 4.62

NC 0.00 0.00 0.00 0.00 0.00 0.00 1.90 0.000 0.00 0.00 0.00 1.90

WS 13.435 0.00 5.343 0.00 0.00 0.00 1.90 0.00 0.00 0.00 0.00 20.68

MS 0.00 0.00 0.00 0.00 3.992 2.839 0.00 0.00 0.00 0.00 0.00 6.83

SA 0.582 0.00 1.944 0.003 0.00 0.00 1.540 0.005 0.00 0.00 0.00 4.07

Prot

0.127 0.00 0.401 0.467 3.60 1.995 0.014 0.00 0.00 11.396 0.00 18.00

RS

0.793 0.00 2.882 0.300 3.96 7.98 0.12 0.00 0.38 0.016 2.786 19.22

SE

11:3

TF, total fat; TS, total solids; MSNF, milk solids not fat (or NMS); NC, “net carbs” = total carbohydrates—dietary fiber—sugar alcohol; WS, whey solids; MS, total milk solids; MF, milk fat; PROT, protein; RS, relative sweetness; SE, sucrose equivalence; NFDM, nonfat dry milk; SA, sugar alcohols; WPC, whey protein concentrate. Note: Stabilizer/Emulsifier = mono- and diglycerides (30–60%), locust bean gum/xanthan gum/guar gum/carrageenan (40–70%).

29.831 44.974 5.554 3.00 4.00 2.85 2.00 0.20 2.00 0.019 5.573 100.00

%

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Cream Water NFDM Inulin Maltitol Erythritol WPC Stabilizer/Emulsifier Resistant Maltodextrin Sucralose Polydextrose Total

Ingredient

Table 6.6. 12.25%-fat, low-net-carb ice cream (Galactomannan stabilizer with emulsifier).

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Table 6.7. No lactose soy frozen desserts.

Ingredients Water Safflower oil Tapioca syrup solids Granulated sucrose Corn syrup 36 DE Stabilizer/emulsifier Soy flour—defatted Soymilk powder Soy protein concentrate/ isolate Total

Soy Flour Version

Soymilk Version

Soy Protein Concentrate/ Isolate Version

61.1035 8.0000 3.3160 13.0000 9.0000 1.0005 4.5800

60.4785 8.0000 3.3160 13.0000 9.0000 1.0005

62.6835 8.0000 3.3160 13.0000 9.0000 1.0005

5.2050 3.0000 100

100

100

spreadsheets (i.e., Microsoft Excel, Techwizard, etc.). Other texts referenced in this chapter (i.e., Arbuckle, Marshall and Goff, UW—Madison Ice Cream Short Course Manual and Penn State’s Ice Cream Short Course Manual, etc.) discuss this subject in considerable detail. The charts used here display ingredients and their addition levels on the left and show the variables of interest on the top line. The central body of the chart details the proportional contribution of each ingredient to each variable of interest. The bottom line accumulates the formula totals for each variable of interest. As one can see the charts can be manipulated to balance and account for a number of different formula variables depending on the product developer’s specific needs (i.e., standard formulas vs. no sugar added or low carb). The variables that need most attention during formulation may vary somewhat depending on the marketing and processing requirements (i.e., lactose-free, fat-free, transfat, fiber claims, protein claims, etc.). Indeed, some product developers use the charts to detail an entire NLEA panel’s worth of information. The chart information mentioned here can also be manipulated (in this case with computer spreadsheets) to generate other performance charts and graphs that can be useful for making formula choices. In this case, we have an example of how one might use this kind of information

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when selecting formulas for a lactose-free, soy-based frozen dessert (Rakes 2005). Note that for soy-based frozen desserts, the level of stabilizer/ emulsifier used would generally be higher since some of the natural stabilizing and emulsifying of milk proteins would be absent. Also, carrageenan has a very strong and specific interaction with milk casein that causes a very large synergistic increase in viscosity for the mix. When carrageenan is used in a soy protein-based system this specific interaction is not present. There may be may be some general ionic interaction between the soy protein and carrageenan but this would result in a much lower synergistic effect than with casein.

Processing Once a frozen dessert is formulated with stabilization referenced and suitably adjusted to all its ingredients and marketing targets (i.e., nutritional, labeling, flavor, cost, processing details, etc.), it is the time to consider how the mix will be processed (i.e., pasteurization, homogenization, and aging), frozen (including the addition of flavors and inclusions), and distributed (including storage). The process begins with raw mix preparation and the dispersion and hydration of ingredients required to accomplish it. Proper dispersion and hydration of the powdered/solid ingredients into the liquid ingredients is required for optimal performance of a formula. This is especially true for the stabilizer and emulsifier ingredients, which are only present in relatively small amounts (<0.5% in most cases). In other words, by way of example, 0.20% of unhydrated (i.e., lumped) stabilizer is likely to have more of a deleterious effect on the finished product than the same amount of unhydrated corn syrup solids or nonfat dry milk. A technical service person at a hydrocolloid company was once quoted as saying that 70% of their applications requiring field support involved improper or poor dispersion and hydration of their hydrocolloids (Hartnek 1988). Homogeneous liquid frozen dessert mixes, without fisheyes or lumps, containing no excessive foam, enable trouble-free processing throughout the plant and provide maximum benefits of the utilized stabilizers and emulsifiers and other solid ingredients for an acceptable and consistent quality final product. At a minimum, one must achieve a raw

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mix that is an evenly distributed suspension (both fat and water soluble solids) with very few (if any) visible lumps (i.e., sometimes referred to as fisheyes), with as little foam as possible being generated. This is the only way to ensure a sufficiently homogeneous mixture going to the pasteurizer and homogenizer. There are a few minor exceptions to the no lump rule for raw frozen dessert mixes that a processor should be aware of. They involve the use of stabilizer/emulsifier combinations with higher melting fats and emulsifiers (i.e., >100◦ F) and sometimes noncold soluble hydrocolloids (i.e., locust bean gum, carrageenan, etc.). The cold soluble gums are usually present in such small amounts that their presence as lumps can be very difficult to detect with the naked eye. As long as there are some cold hydrating ingredients in the formula that produce some visible increase in mix viscosity, the unhydrated and small gum particles should be suspendable in the mix and should remain dispersed if there is a reasonable level of agitation in the raw mix tank and balance tank for high temperature short time (HTST) systems. Some raw mixes will have white, tapioca-like particles floating around in them. These particles are unmelted fat and/or emulsifier and are to be expected if the composition of the mix and emulsifier are known ahead of time. As long as their level does not exceed 1%, they should not be a problem (i.e., remain suspended and dispersed) for normally and sufficiently agitated processing tanks and balance tanks for HTST systems. Batch pasteurization tanks and systems usually have less reason for concern about these products since the heating takes place in the same tank as final mix incorporation steps do. This statement of course assumes that the powders are incorporated into the liquids with sufficient shear to avoid lumping. This subject is discussed further on the following pages. Lower fat and nonfat mixes can pose a challenge with respect to foam generation. Often times they require some preheating of the raw mix accompanied by some quiescent hydration time in the raw mix tank prior to pasteurization in order to allow the foam to rise to the top of the tank and dissipate. If some defoaming is not undertaken, the mix will run very unevenly through the pasteurizer causing large fluctuations in pressure and temperature, and hence slowing down the process and creating inconsistencies and possible defects in the finished product. Batch pasteurizers usually have less difficulty with these mixes since the heating takes place in the same tank as some of the ingredient

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incorporation usually does; hence heating of the mix under slow agitation to defoam the mix is usually facile. Lumps or fisheyes are incompletely hydrated bodies of powder (i.e., slimy, sticky exterior with a dry interior) that have been stifled in the process of complete dispersion, hence full hydration of all the ingredients is no longer possible or practical without extreme shear being applied to the mix. These lumps make the ingredients unavailable for use in the formula and hence in effect start to undesirably change their effective concentrations in the finished product. It has been stated by some hydrocolloid manufacturers (Clark 1990), as a general rule of thumb, that effective commercial hydration of gums requires at least 90% of complete hydration. Avoidance of these lumps requires attention to the details of how the powders are mixed with the liquids (i.e., equipment and handling concerns) and how initial dispersion may be aided by having the powders combined (i.e., more hygroscopic ingredients dry mixed with larger amounts of less hygroscopic ingredients and/or coated with fats or emulsifiers) prior to liquid incorporation. Depending on the specific ingredients and the particular mixing equipment/process involved, sometimes the order of addition of the dry ingredients and liquids can make a difference in the characteristics of a raw mix and hence possibly the final product. As a general rule of thumb, the typical sequence of dry ingredient incorporation (Darcy 1999) into water, milk, skim milk, soymilk, or condensed milk (or usually combinations of these for frozen dessert mixes) is as follows: 1. Dry dairy/soy/rice, etc. products (nonfat dry milk, whey protein concentrate, soy protein concentrate, rice protein concentrate, egg yolk solids, sweet whey, buttermilk, etc.) go in first. Since they generally create more foam or incorporate air into the mix, these ingredients need to be mixed in the batch tank as long as practical to allow the excess air to escape from the top of the mix before the introduction of stabilizers and emulsifiers. 2. Dry sweeteners (sugar, corn syrup solids, rice syrup solids, tapioca and potato maltodextrins, etc.) should be added second. 3. Other dry ingredients like cocoa, polydextrose, inulin, sorbitol, maltitol, erythritol and other polyols should be added in next. 4. Lastly the stabilizer/emulsifier should be added with sugar or some other less hygroscopic powder being used as a dry blend dispersant. Sometimes the stabilizer/emulsifier will be coated or encapsulated

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with a fat and/or emulsifier or other substance that aids in the initial liquid dispersion steps. The coated/encapsulated products often work better in processing systems with less than optimal mixing equipment. There are individual exceptions to the above-mentioned regime that will occasionally need to be made depending on the plant, the equipment used and the peculiarities of the mix formulation in question. In some cases preheating of the liquids is advisable to minimize foam and speed up the hydration of marginally cold soluble ingredients like some maltodextrins and corn syrup solids. The trick is not to preheat too high for too long to avoid unnecessary protein denaturation and fat oxidation or various types of flavor deterioration. What follows is an idealized example (Tresser 1989) for a total raw mix preparation method for a typical HTST pasteurization system: 1. Fill the raw mix tank up to one-third full or to at least cover the agitator with liquid ingredients such as milk, soymilk, rice milk, liquid sugar, water, etc. 2. Start and continue high-speed agitation of the raw mix tank in the steps outlined below. (Note: Two-speed agitators are preferred for raw mix batch tanks. High speed is for blending; low speed is for when supplying the HTST. Also, the raw mix batch tanks should ideally be equipped with a baffle set perpendicular to the flow of the mix in order to create enough turbulence to prevent stratification of fat and less than completely hydrated materials and to help in the removal of air/foam [Darcy 1999]). 3. Pump stabilizer slurry (see attached examples) immediately from the blender (i.e., powder incorporation equipment) to the raw mix tank. Addition of the stabilizer/emulsifier preblend to the raw mix at this point provides sufficient time for the stabilizer to completely disperse and partially hydrate. 4. Partially fill the blender with liquid sugar, milk, soymilk, rice milk, batching water, other syrups, or suitable combinations of liquids to generate the necessary minimum mixing volume. 5. Start agitating the blender or other powder incorporation equipment at high speed. 6. Add powdered ingredients per the previously mentioned guidelines for order of addition of dry ingredients. Minimize blending

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times to reduce air incorporation. Experience shows that 2–3 minutes of blending time is sufficient to properly disperse these ingredients when the powder incorporation equipment design is optimized. 7. Pump solids preblend(s) into the raw mix tank. Repeat steps 4–7 until all the solids are incorporated. If salt is used in the formula it should usually be added last just before the addition of the major fat sources. 8. Pump cream, AMF, butter oil, vegetable oils, etc. and/or other significant fat sources into the raw mix tank as the last ingredient addition to the mix. 9. Following the addition of fat sources, agitate the raw mix tank at low speed and pump the mix out for pasteurization as soon as possible. Additionally, what follows is a series of scenarios for preparing stabilizer slurries (per the above procedure) with different types of normally encountered equipment in the frozen dessert industry (Tresser 1989). Dispersion of the Stabilizer without Dispersing/Hydrating Equipment When no dispersing/hydrating equipment is available, a stabilizer dry blend can be introduced directly into the raw mix tank. Dry blending the stabilizer with granulated sugar or nonfat dry milk or soymilk powder or whey powder, etc. in a 1:3 ratio (one part stabilizer to three parts sugar) will result in improved dispersibility of the stabilizer into the liquid raw mix. Care should be taken that the stabilizer dry blend is homogeneously mixed prior to incorporation into the liquid mix. A homogeneous dry blend is one which has a uniform color when poured from the mixing container. 1. The raw mix tank should be filled with liquid ingredients high enough that the agitator is well covered. 2. Start the agitator. High shear agitation is essential for dispersion of solids into a liquid mix. 3. Sprinkle the stabilizer dry blend slowly into the liquid mix. 4. Mix for at least 10–15 minutes to properly disperse the stabilizer.

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Dispersion of the Stabilizer Using a Dispersion Funnel A dispersion funnel can serve a low-cost alternative to a liquifier/blender or a Tri-Blender. If the dispersion funnel is used and cared for properly, it eliminates lumping of stabilizers when these are added into the raw mix tank, even when the raw mix tank does not have the proper high shear mixing equipment. 1. 2. 3. 4. 5.

Connect the funnel to the water supply line. Use cold water only. Start the flow of water through the funnel. Fill the raw mix tank with liquid so that the agitator is well covered. Start the agitator. Fill the hopper of the dispersion funnel with stabilizer.

Important: The water flow through the funnel must be started before the stabilizer is added to the hopper of the specialized dispersion funnel and must be kept up until all of the stabilizer is dispensed from the hopper. Sufficient water flow is required to generate a suction effect on the powdered stabilizer as well as to generate sufficient turbulence in the pipe leading to the raw mix tank. (Note: This device is a specialized version [i.e., specialized pipe connection and housing] of a simpler device often referred to as a powder horn, which is just a cone-shaped funnel connected perpendicularly to a pipe with relatively little suction or turbulence being generated.) Dispersion of the Stabilizer Using a Tri-Blender Stabilizer and other powdered ingredients of a frozen dessert formula can be very efficiently dispersed with a Tri-Blender if air incorporation is avoided. 1. Connect the Tri-Blender to the raw mix tank. 2. Close the butterfly valve at the bottom of the hopper. 3. Fill the hopper with granulated sugar, nonfat dry milk, soymilk powder, whey powder, etc. 4. Add stabilizer onto the contents of the hopper. Premixing of the contents of the hopper prior to introduction of these ingredients into the liquid mix can be helpful. 5. Start the Tri-Blender.

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133

Start the supply pump. Open the butterfly valve. Dispense the contents of the hopper into the liquid mix. Close the butterfly valve. Recirculate for 3–5 minutes. Stop the Tri-Blender. Stop the supply pump. Disconnect from the raw mix tank and clean the Tri-Blender.

Care has to be taken that the hopper is always containing at least a little powder at the bottom while operating. This prevents incorporation of air into the liquid mix. Closing the butterfly valve immediately after dispensing the contents of the hopper and during recirculation serves the same purpose. Dispersion of the Stabilizer in a Liquifier/Blender This is one of the more popular and preferred means for making stabilizer slurry. When properly used, this equipment tends to give the most trouble-free and consistent stabilizer slurries. Liquid sugar, warm batching water, milk, rice milk, and soymilk can be used as dispersing liquids in this type of equipment. One general rule of thumb is to keep the fat level of the dispersing medium (especially in dairy frozen desserts) below 10% when possible. Since this type of equipment is sometimes jacket heated, it’s also important to keep the temporal concentrations of protein in the dispersing medium below the gelation point as much as is practical (e.g., soy protein in the presence of high calcium levels). 1. Fill the blender with the liquid dispersing medium of choice to approximately half to two-thirds full. 2. Start agitating at high speed until a vortex is formed. 3. Add the stabilizer by sprinkling it slowly into the blender at the edge of the liquid vortex for maximum speed of dispersion. Add slowly enough to avoid the formation of powder lumps on the top of the dispersing liquid. 4. Continue blending for no longer than 30–40 seconds to avoid excessive air incorporation or until there are no visible powder lumps in the slurry. Depending on the viscosity of the slurry liquid and

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hydration characteristics (i.e., particle size, relative hygroscopicity, etc.) of the hydrocolloids used, somewhat longer blending times of a minute or so may be needed on occasion. 5. Stop the blender. 6. Pump the stabilizer slurry into the raw mix tank immediately. Note: If milk, soymilk, rice milk, water, or fat-containing fluids are used as dispersing agents in the liquifier/blender, the dry blending of the stabilizer with granular sugar, nonfat dry milk or soymilk solids, etc. at a ratio of one part stabilizer to three parts or more of the other powders can be helpful to avoid lumping of the stabilizer when rapid addition of the powders to the liquids is required by production considerations. Care should be taken to ensure that the dry blend of stabilizer and other powders is uniformly mixed to take full advantage of the dispersant effect of the other powders. Further, there are some simple checks one can make for evaluating the efficacy of the mix-making procedures. They are as follows. Checklist for Dispersion and Hydration of Stabilizers in Frozen Dessert Mixes 1. Slurry in the liquifier/blender—Following the dispersion of the stabilizer, especially when liquid sugar is used as the dispersing agent, the slurry can be checked by extracting a small amount from the blender for observation. This slurry should only contain a small number of air bubbles and be somewhat opaque if not almost transparent. 2. Mix in the raw mix tank—The empty tank should be checked for residual stabilizer particles and excessive foam after the mix is pumped out. Few, if any, small stabilizer particles should appear if the blender and the agitator in the raw mix tank have been working effectively. Foam residues in the bottom of the tank should be minimal also. 3. Mix in the HTST balance tank—A small sample of the cold raw mix from the HTST balance tank should be placed in a petri dish. Only a very few air bubbles should be apparent in this mix. When contents of the petri dish are allowed to dry, tiny specks of stabilizer are normally visible. Larger stabilizer agglomerates (i.e., visible lumps) should not be present.

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4. Mix following the HTST heat treatment—The pasteurized mix should show a small number of air bubbles, if any. No stabilizer or solids particles should be detectable when the mix is observed in a petri dish. If the mix viscosity seems to be excessive, one should first check for air incorporation problems by allowing a sample of the mix to set in a graduated cylinder for 30 minutes to 1 hour in a quiescent state to allow the foam to rise to the top. Mild microwave heating of the mix to 90–100◦ F can hasten this process somewhat. Also mild centrifugation (i.e., <200 RPM for <5 minutes) of a mix sample can show evidence of foam. The methods of pasteurization and homogenization of the mix are also relevant considerations when choosing some bulk ingredients and stabilizers for frozen dessert formulations. Frozen dessert mix pasteurization is normally conducted in one of three ways: batch, HTST, and UHT (ultra high temperature). Batch pasteurization is usually conducted in a jacketed and steam sealed tank with agitation. It usually involves heating the mix formulation in a tank under agitation to a temperature of at least 155◦ F (or preferably higher) for 30 minutes. Specific times and temperatures may vary with the type of product and the preference of local regulatory authorities. Batch pasteurization is usually followed by direct pumping to a homogenizer, sometimes preceded by partial cooling. Following homogenization, the mix is usually cooled in a heat exchanger to a temperature of 40◦ F or lower, prior to entering the refrigerated aging tanks. Well-executed batch pasteurization has the advantage of being able to handle many different types of heat activated/hydrated/melted ingredients (i.e., locust bean gum, carrageenan, many starches, high melt fats, etc.) with relative ease compared to continuous methods. Batch pasteurization also has a tendency to impart cooked flavors to varying degrees depending on the ingredients used. Sometimes, the cooked flavors are desired but, in some cases, they are not. The main limitation to batch pasteurization is the cap it tends to put on overall plant productivity per unit of time versus most continuous methods (Marschall and Arbuckle 1996). The energy efficiency of this process is also less than optimal in many cases. There are a few manufacturers that have undertaken the task of constructing so-called semi-continuous batch pasteurization systems with

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multiple tanks and recirculating pumps with additional heat exchangers that help with the productivity issue as well as the consistency of heat treatment. They tend to be expensive from a capital equipment cost viewpoint. HTST pasteurization is usually conducted in a continuous flow heat exchanger system with pumps, homogenizers, and defined hold tubes, all connected in line. The mix usually comes relatively cold (<70◦ F) from the raw mix tank into a balance tank prior to entering the first heat exchanger (tubular or plate style). The mix is then heated to 120–165◦ F for raw side homogenization, sometimes by thermal regeneration with the already pasteurized product. The preheated mix is continuously fed to the homogenizer where either single or double stage homogenization takes place. Subsequently, the homogenized mix is fed to a second heat exchanger(s) to heat the mix up to 180◦ F (varies with product and local regulatory authority) before going into a hold tube for 16 seconds or longer (varies with the product and local regulatory authority). The pasteurized mix is then cooled through a series of heat exchangers (sometimes involving thermal regeneration with the cold incoming raw mix) to 40◦ F or colder prior to entering an aging tank for refrigerated storage. There are some HTST systems that rearrange this flow pattern to use the homogenizer on the pasteurized mix side of the process. In other words, the homogenizer would be located just before or just after the hold tube, and it would be handling the mix at 180◦ F or higher in many cases before sending the mix onward for cooling. The prime advantages for HTST systems versus batch pasteurization are the gains in plant productivity, increases in energy efficiency, and reduction in cooked flavors (if desired). The one disadvantage can be some difficulty in dealing with heat-activated ingredients on the raw side of the processing system. Variations on the HTST flow scheme mentioned above are sometimes undertaken by some manufacturers to alleviate problems with heat activated ingredients on the raw side (i.e., preheating in the raw mix tank). Extensions in the hold tube to 1–3 minutes are not unheard of for getting back the cooked flavor that some customers desire. Partial shelf-life extension has been accomplished with HTST processed frozen dessert mixes, primarily for soft serve application, by injecting carbon dioxide into the mix during the filling and packaging operations (Praxair 1997). Also, some soft serve mix manufacturers preserve their mixes by hard freezing them in their containers (i.e., no whipping or overrun inclusion) just after pasteurization

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and cooling. The frozen container is then shipped to the customer and thawed out for use in a refrigerator on an as needed basis. UHT pasteurization is used on frozen dessert mixes in selected circumstances where extra shelf life is needed, but hard freezing the container is not feasible from a cost standpoint, product quality standpoint, or transportation standpoint (i.e., export markets, special institutional markets, large soft serve mix manufacturers, etc.). It is almost always conducted in a continuous fashion (i.e., retort/batch heating of frozen dessert mixes is relatively rare) similar to HTST operations with homogenizer placement in the flow scheme being a possible variable. Because of the higher temperatures involved, the equipment and types of heat exchange may vary somewhat from typical HTST systems (Bylund 1995). The higher temperatures are often attained by using direct steam contact with the product in preference to indirect heat transfer through stainless steel (i.e., plate and/or tubular heat exchangers) because of the markedly shorter come-up times and fewer problems with heat exchanger fouling/burn on. As well, the shorter come-up times involved with direct steam injection or infusion generally result in better product flavor and functionality, although these outcomes can vary greatly with the formulation. The energy efficiency of the process can vary significantly with the particular system (i.e., indirect heat transfer gives greater thermal regeneration while direct steam contact systems lose some of their thermal regeneration potential in the vacuum chamber used to flash cool the product below the boiling point). When coupled with suitable packaging equipment (i.e., aseptic or ESL [extended shelf life]) UHT continuous systems can be very productive. The capital costs for UHT systems tend to be significantly higher than for HTST systems. Other pasteurization technologies are in development at this time but they do not yet have approval for use on frozen dessert mixes in the United States. They involve microwave energy, ultra high pressure, and electrovoltaic pulsing. Homogenization of the frozen dessert mixes is an important step that takes place in the midst of the pasteurization process. The purpose of the process is to reduce the size of fat globules in the raw mix to make it easier to form a stable emulsion (usually oil in water type) out of the mix prior to freezing. The process also reduces the size of other partially hydrated solids in the mix and thus gives it more uniformity.

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It is important to modulate the process where practical to produce a finished frozen dessert mix that is only just stable enough (i.e., no fat or serum separation) for the intended shelf life (i.e., 72 hours for most hardpack applications, 2 weeks to many months for various soft serve applications) yet still be susceptible to the partial agglomeration of fat that usually occurs during the freezing process to make stable air cells (Goff 2005). Nonfat frozen dessert formulas (i.e., fat-free ice cream, sorbets, water ices, etc.) tend to be exempted from the necessity of this process. As to the business of deciding what pressure(s) at which to homogenize the mix, whether to use multiple stages (usually only two unless product recycle is involved), and the valve design to use, there are many references on this topic (i.e., Food Engineering, Kessler, Ice Cream, Goff et al. and many others). In most cases, the mix in the United States will be subjected to 2-stage homogenization with the first stage pressure ranging from 1,000 to 3,000 PSI in most cases and the second stage pressure hovering around the 100 to 500 PSI range in most cases. Higher pressures (i.e., 5,000 PSI or higher) are possible but not often used for most frozen desserts in the United States. Regarding the temperature of mix homogenization, it can be said that the product developer is often locked into a preexisting regime for upper limit pressures and the temperatures by the design of a specific continuous processing system. In general, the temperature of mix homogenization is higher than the melting point of any and all fats present in the formulation (i.e., usually 120◦ F or higher) to maximize emulsion formation and prevent channel clogging. Homogenization temperature is lower than the boiling point for the mix to prevent pump cavitation (i.e.,195◦ F or lower usually). More specific recommendations on homogenization temperatures and sometimes pressures may evolve depending on the ingredients (i.e., some starches and cellulose fibers) that are put into a frozen dessert formulation. Once the pasteurized and homogenized frozen dessert mix is made, the refrigerated storage or aging before the freezing process needs to be taken into consideration. In general, the frozen dessert industry likes to say 4–6 hours minimum with overnight (i.e., 12 hours) being the best. Commercial realities of production economics do not always permit adherence to these numbers. The actual optimums and minimums depend on the temperature of the refrigerated mix and the ingredients in the formulation. The

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hydrations of stabilizers and proteins tended to be the rate-limiting factor in the past. Now it is more often the crystallization of fat that tends to be the rate-limiting factor for the aging process. In general, the more saturated the fat and the lower the mix temperature, the faster the crystallization of the fat in the mix will go (Croft and Hammond 1994). The particular selection of emulsifiers for some formulas can also have an effect on the optimal aging time and temperature. Empirical testing of each formula in its specific production conditions is usually required to identify a particular set of optimum aging conditions. The purpose of aging is not only to complete the hydration and crystallization of appropriate ingredients but also to potentiate the mix toward easy and stable aeration during the freezing process. There is one exception to the normal aging process that is relatively new on the soft serve side of the frozen dessert business. Some frozen dessert mixes now are available in a dry mix reconstituted format, wherein the solids are delivered powdered and premeasured for simple incorporation into water in a bucket, pitcher, or blender. Sometimes the reconstituted frozen dessert mix is allowed to chill in a refrigerator for a few hours before freezing, and in other cases it is not (i.e., reconstituted in cold water or put into the soft serve freezer at room temperature). In either case, there is little time for much fat crystallization to take place and only a minimal amount of time for the rest of the ingredients to hydrate. The advantages of this type of process are cheaper storage costs, smaller inventories, longer mix shelf life, and easier right-sizing of mix availability to demand. Proper ingredient sourcing and selection is critical for the success of such a product. It is also vitally important to ensure the proper sanitation level of the equipment, ingredients, and water or other liquid used to hydrate the powdered ingredients since no liquid pasteurization is involved. Once the frozen dessert mix is pasteurized, homogenized, and aged or otherwise hydrated (i.e., dry mix reconstitution) it is time for the freezing process to commence. Mix is usually frozen in one of the following ways: 1. 2. 3. 4. 5.

Batch freezing (soft serve and hardpack) Conventional continuous Low draw, modified continuous Extruded novelty Quiescently frozen novelty

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6. Mousse process (i.e., refrigerated whip with in-container hard freezing) 7. Cryogenic freezing (i.e., liquid nitrogen or carbon dioxide) All of these freezing methods can be used to make high quality frozen desserts.

References Baer R.J. and Baldwin K.A. 1984. Freezing points of bulking agents used in manufacture of low-calorie frozen desserts. J Dairy Sci, 67:2860–2862. Bylund G. 1995. Dairy Processing Handbook. Tetra Pak Processing Systems AB: Vernon Hills, Illinois, p. 78. Clark R.C. 1990. Personal Memorandum. Croft S. and Hammond P. 1994. Food Systems Ice Cream Evaluation Manual Version 8. NZDRI: Hamilton, New Zealand, p. 17. Darcy A. 1999. Personal Memorandum. DeYoung R. 1989. Personal Memorandum. Goff D. 2005. Homogenization of Ice Cream Mix: Should I Go High or Low? IDFA Ice Cream Technology Conference, March 2–4, Scottsdale, Arizona. Hartel R.W. 2006. Personal Memorandum. Hartnek H. 1988. Personal Memorandum. Hopkinson J. 2006. Ingredient Technology to Control Heat Shock. IDFA Ice Cream Technology Conference, March 1–3, St. Petersburg, Florida. Marschall R.T. and Arbuckle W.S. 1996. Ice Cream, 5th ed. Chapman and Hill: New York, p. 37–38. Marschall R.T., Goff H.D., and Hartel R.W. 2003. Ice Cream, 6th edn. Springer: New York, p. 180. Praxair Company 1997. Carbon Dioxide: Adding Shelf Life to Ice Cream. Announcement, May 7, 1997. Rakes P. 2005. Formulating Low/No Lactose Frozen Desserts, Prepared Foods. R&D Conference—Dairy/Novelty Session, September 19–20, Oak Brook, Illinois. Schenz T.W. 1994. Glass transitions and product stability—An overview. Food Hydrocolloids, 9:307–315. Smith K.E. and Bradley R.L. 1983. Effects on freezing point of carbohydrates commonly used in frozen desserts. J Dairy Sci, 66:2464–2467. Tresser L. 1989. Personal Memorandum.

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Chapter 7 Hydrocolloids in Cultured Dairy Products Joseph Klemaszewski

Cultured dairy products include a wide range of product textures and flavors within the category and even sometimes across geographical regions for the same product. Reasons for this range from availability of milk supply, species from which milk is obtained, shipping considerations, traditions, processing constraints, regulations, and taste preferences. This chapter illustrates some examples of stabilization of cultured dairy products primarily in the North American market. The cultured dairy products categories covered are cheese, buttermilk, sour cream, and yogurt. Stabilization of cultured dairy products involves the interaction of ingredients including water, lipid, protein, sugars, cultures, and hydrocolloids. The contributions of nonhydrocolloid ingredients, especially cultures, cannot be overlooked when formulating or troubleshooting. Lactic acid bacteria produce acids, enzymes, and polysaccharides, which can positively or negatively affect texture and flavor. Additionally, the conditions under which the cultures ferment result in different growth rates and by-products. These components have been the subjects of many studies and are beyond the scope of this chapter. Texture in cheese products covers the spectrum for soft fresh cheeses like brie, queso blanco, and spreadable cream cheese to hard grating cheeses like Parmesan and Romano. In the United States, hydrocolloids are not allowed in most standardized cheeses with exceptions like Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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cottage cheese, cream cheese, pasteurized process cheese spread, and cold pack cheese food. Another notable exception is nutritionally modified cheeses which allow for the addition of other ingredients if there is a benefit when replacing a macronutrient. An example of this is lowfat mozzarella where fat is replaced by water alone, resulting in a soft cheese that cannot be shredded. Nontraditional ingredients, like hydrocolloids, can be used to bind the water and give a texture closer to the full fat target. Yogurt Yogurt consumption has increased dramatically in the United States in the last 30 years. The changes in the flavor and texture of the yogurts in North America have also changed considerably over this period. Traditional yogurt is made by a cup set process and does not contain added sweeteners or texturants. Most of the yogurts sold in the United States today are sweeter with a smooth texture closer to pudding. Products in Western Europe and some Canadian products are closer to the traditional yogurts. Standards of identity in some countries, such as France, do not allow for the inclusion of stabilizers in the yogurt white mass. Stabilizers are allowed in yogurt marketed in the United States, per 21 CFR 131.200, when used in accordance with good manufacturing practices. There are no federal standards for yogurt in Canada; however provinces may have limitations on stabilizing ingredients. Fruit preparations may also contain sweeteners and stabilizing ingredients, and these may be subject to other regulations. The pH, total solids, processing conditions, and regulations for the fruit are very different from the white mass, thus the stabilization requirements as well as the regulations for fruit preparations differ. While most yogurts contain fruit or bulky flavor ingredients, they are not typically processed in a dairy plant and are not covered in detail in this chapter. Strawberries are the most popular bulky flavor added to yogurt in North America. Diced or sliced strawberries are typically processed with sweeteners, flavors, stabilizers, and optional colors. The resulting fruit preparation is added to white mass at levels ranging from 10 to 20%. Some nonfruit flavorings, such as vanilla, are also incorporated as a “vanilla fruit prep” to provide a product with a texture similar to fruit-flavored yogurts. Equipment for mixing and packaging stirred

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yogurts can be set to add the same level of bulky flavor ingredients and facilitate easier transitions to packaging other yogurt flavors. All yogurt manufacturing begins with milk pasteurization. Higher temperatures and longer hold times are used for yogurt production than most other cultured dairy products. Continuous processing can have hold times of 1–10 minutes at 185–200◦ F. Vat pasteurization at 160◦ F for 30 minutes is not uncommon, and the come-up time and cool-down time for the vats results in significant denaturation of the whey proteins. The denatured protein results in a firmer yogurt texture and shorter incubation times. Spoonable yogurt is made by either a cup set process or a vat set process. Cup set yogurts are made by adding inoculated white mass, which has not undergone significant fermentation. Fruit may be present in the bottom of the cup at the time of filling for a fruit on the bottom yogurt. The yogurt cups are then incubated until the desired pH is reached. Yogurt cups are then placed in a cooler. Because cup set yogurts do not see significant shear until the time of consumption, coagulated proteins and culture-produced polysaccharides contribute significantly to the texture. These contributions can be altered by changes in the incubation temperature, protein content of the white mass, casein to whey protein ratio, total solids of the yogurt, culture strain selection, and stabilizing ingredients used. Vat set yogurts, also called stirred, are made by culturing white mass to a target pH, then cooling and stirring the yogurt. The yogurt is then pumped out of the vat, and fruits are mixed with the yogurt prior to filling the cup. In addition to the factors mentioned with cup set yogurt, the amount of shear in this process has a significant impact on the finished yogurt texture. The viscosifying contributions from the fruit preparation are also more significant in a vat set yogurt as the fruit and sweetening matrix are dispersed throughout the yogurt. In both cup set and vat set yogurt, changes to the flavor and texture occur as culture growth continues at a slow pace. The majority of yogurts manufactured in the United States is Swissstyle, or stirred, stabilized with modified food starch, typically from waxy maize, and gelatin. Starch is commonly used at 2–3% in vat set yogurt and at a lower level in cup set yogurts. Yogurt manufacturers that want to make claims about natural, organic, Kosher, Halal, or vegan may use alternate stabilizers if any are added. Natural yogurts can be stabilized with modified starches from corn, tapioca, potato,

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and/or rice. These are used in the white mass in combination with hydrocolloids. Commonly used hydrocolloids are pectin and locust bean gum. Low methoxyl pectins are used because of their ability to form a gel at lower solids levels compared with high methoxyl pectins. Gelling properties of low methoxyl pectins can be enhanced by amidation. Pectin from apple and citrus are used in yogurts and the botanical source also provides differentiation to a lesser extent than amidation and degree of esterification. Pectin on a yogurt label can also be from the fruit preparation, which may be a high or low methoxyl. Carrageenan is used in a small number of yogurts. Because of its milk protein reactivity, the level of carrageenan used is usually less than 0.1%. Extracts with higher levels of ␬-carrageenan, high levels of milk protein in the white mass, and more severe heat treatments contribute to milk protein reactivity. Yogurts made with too much carrageenan have a curdy texture. Carrageenan is also used in some fruit preparations, more so in Europe than in North America. Because starch is widely used in North American yogurts and other cultured dairy products, attention must be given to the starch source, chemistry, and processing. Most of the starch used in yogurt is crosslinked and substituted cook-up cornstarch from waxy maize hybrids. Waxy cornstarch consists of branched amylopectin with less than 1% linear amylose. Amylose forms a firm brittle gel, which can expel water as the starch undergoes retrogradation during storage. Steric hindrance of the amylopectin branches prevents retrogradation and gel formation. Thus yogurt made with waxy cornstarch has less syneresis and a less brittle structure. Starch from dent (also called common) corn contains 25–30% amylose, with the remainder being amylopectin. Modified starch from common corn is rarely used in some yogurts, and in some instances can be combined with waxy cornstarch. High amylose starches contain 50% or more amylose and require heating above 212◦ F to swell and provide optimal functionality. High amylose starch is not used in cultured dairy processing, as the gelatinization temperature cannot be reached using equipment common to most cultured dairy plants. Tapioca starch contains 15–20% amylose and imparts a creamier texture to yogurt with less flavor masking than cornstarch. However, tapioca starches are usually more expensive than cornstarches, so their use in yogurt is limited more by economics than functionality. Unmodified starches are limited in their ability to withstand shear, temperature abuse, acid, and freeze-thaw conditions. Pasteurization and

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homogenization are sources of shear common in dairy manufacture. Lactic acid bacteria lower the pH of yogurts to 4.0 or less throughout the shelf life. The changes in starch, along with changes in protein interactions, are common factors in loss of viscosity and lack of smoothness in yogurt as the product reaches the end of its shelf life. Freeze-thaw stability is a consideration for tube yogurts that are marketed as an alternative to frozen novelties. The two types of starch modifications used in cultured dairy products are cross-linking and substitution. These modifications can be used on starch regardless of botanical source and are described in 21 CFR 172.892. Substitution increases starch water holding capacity and peak viscosity, provides freeze-thaw stability, reduces syneresis, gel formation, and retrogradation, and decreases gelatinization temperature. Cross-linking improves heat stability, acid stability, shear tolerance, and gelatinization temperature, but decreases peak viscosity. Starches with higher levels of substitution are easier to cook out with a HTST pasteurization process and give yogurts better stability. High levels of cross-linking provide more stability to homogenization, but sacrifice viscosity. A starch with a lower level of cross-linking that can survive the yogurt making process intact can be used to achieve the same finished product viscosity as a starch with a higher level of crosslinking. Alternatively, a higher amount of starch with a low level of cross-linking must be used to achieve the target viscosity if the starch is broken down by processing. Figure 7.1 shows the effects of cross-linking and processing conditions on finished yogurt viscosity. The low shear condition represents a process with a low or no homogenization such as nonfat yogurt. An example of a very high shear condition is homogenization following vat pasteurization. Under low shear conditions, a starch with a low level of cross-linking provides the highest viscosity. If this starch is processed under more rigorous conditions, the starch granules are destroyed resulting in a much lower viscosity. Increasing the level of cross-linking results in more intact starch granules after processing, as cross-linking limits the amount of swell in a granule. Any amount of cross-linking exceeding the amount needed for the severity of the process prevents cost optimization. Dairies that utilize the same starch for unhomogenized nonfat yogurt and homogenized lowfat yogurt are reducing the number of items inventoried at the expense of formula optimization. Process optimization to lower the amount of shear in order to decrease

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Apparent viscosity (cP @ 50 1/s)

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Low shear High shear

Low XL

Med XL

High XL

V. High XL

Level of cross-linking (XL)

Figure 7.1. Effects of shear and starch cross-linking level on yogurt white mass viscosity.

the amount of cross-linking and stabilizer level has potential economic and flavor benefits. The ability of a starch to withstand the rigors of processing is also dependent on the formulation, pasteurization time and temperature, thermal history before homogenization, substitution level, substitution chemicals, cross-linking agent, botanical source of starch, and shear from processing before and after culturing. Microscopic evaluation of iodine-stained yogurt is used to determine the degree of cook and overprocessing of starch. Figure 7.2 shows examples of properly cooked and overprocessed waxy maize starches. Evaluation in yogurt white mass is easiest prior to culturing and must be done prior to the addition of fruit preparations that contain starch. After milk proteins, cultures, and starch, gelatin is the most widely used thickening agent in spoonable yogurts. Gelatin’s properties include thermo reversible gelling, elasticity, sheen, ease of processing, clean flavor release, and melting point near 95◦ F. Common commercial sources of gelatin are beef hides and bones, pork skins, and fish skin. Because of its animal source, concerns about gelatin have been raised by various groups for suitability in vegetarian diets, Kosher and Halal certification, and infectious agents like hoof-and-mouth disease (9 CFR 94.18c) or

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Figure 7.2. Micrographs of modified waxy corn starch obtained at two stages of cooking. Starch on the left is properly good and gives maximum viscosity. The sample on the right is overcooked and has lower viscosity. (Microscopy courtesy of A. Peck—Cargill, Inc.)

bovine spongiform encephalopathy (USDA 1997). Replacing gelatin has been the target of food ingredient suppliers in a broad range of food applications including yogurt. The wide use of gelatin in yogurt today demonstrates the unique benefits from this ingredient. Textural improvements in yogurt can be obtained with shear after culturing, and the gelling properties of gelatin are well-suited for this process. Postculture shear is needed to incorporate fruit, and higher levels of shear produce a smoother textured yogurt with more sheen. Since gelatin requires some time and low temperatures to set, yogurts can be cooled for short periods of time prior to filling, without complete loss in gel structure from gelatin. By contrast, starch will lose significant viscosity when sheared. Another benefit of gelatin is lower back pressure during processing than other hydrocolloids. Gelatin is available in a range of gel strengths, as measured by bloom, from 50 to 300. Use level depends on processing, bloom strength, and desired viscosity and can range from 0.3 to 1%. Excessive levels of gelatin result in a brittle gel and a lack of smoothness. In addition to being consumed for calcium and protein, yogurts are consumed for the digestive benefits. The marketing of yogurts with

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probiotic cultures and digestive benefits has been underway for some time in Europe and Asia. As this market develops in North America, companies are also increasingly marketing yogurts with dietary fibers. Most hydrocolloids are a source of dietary fiber but do not contribute significant amounts to the diet because of their low use level. In order to qualify as a good source of fiber, a product must provide 2.5 grams of fiber per serving. In 6 ounces of yogurt, this equates to a use level of 1.5–2% depending on the level of fiber in the ingredient. This yogurt would be too thick to process and package if a hydrocolloid like guar gum was used. Inulin or chicory fiber has been used in yogurt for several years by a few companies in the United States. Inulin recently obtained approval for use in yogurt in Canada as a source of fiber that can be claimed in product labeling. Several types of inulin are commercially available with varying chain lengths. Longer chain lengths impart less sweetness and provide some creaminess and viscosity. Inulin is added to yogurt primarily for its health benefits including increased calcium absorption and digestive health. Insoluble fibers are not usually added to yogurt white mass as they impart chalkiness. In the course of yogurt manufacture, there will be times when the product does not meet specifications, and troubleshooting always begins with identifying process deviations. Some common causes of textural defects are improper incubation temperature, wrong break at pH, omission of ingredients or errors in weighing, and contaminants. Enzymes and growth inhibiting contaminants, such as phage, may not be harmful from a food safety standpoint but can ruin a day’s production from an economic standpoint. Amylase can be present in a number of ingredients including fruits and berries, and the effects of this enzyme on starch may not be observed until the yogurt has entered distribution. Special consideration needs to be given to unintended ingredients as new flavors are developed with nontraditional fruits. The popularity of yogurt has led to an increase in the number of products introduced with yogurt and new yogurt products. These include nutritionally modified yogurts (light, low carb, no sugar added), dessert yogurts, aerated yogurts, yogurt dips, drinkable yogurts, and yogurts for children and toddlers. Many of these products vary in sweetness or fat content, and may require stabilizer adjustments to account for the change in solids or desired texture. Whipped yogurts require higher levels of stabilizers plus a surfactant such as lactic acid esters of monoand diglycerides to help incorporate air.

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Another style of yogurt in the North American market is Greek style or strained yogurt. These yogurts are high in fat and total solids and the traditional manufacturing process includes a whey separation step. This process resembles cheese production more than yogurt and stabilizers are not typically used unless a flavored product like tzatziki sauce is made from the yogurt. Yogurt and dips with a texture similar to the strained product can be made with traditional yogurt manufacturing equipment by altering the stabilizer and processing.

Drinkable Yogurt and Smoothies Yogurt sales in the United States have increased annually for 20 years and now represent over half the volume of cultured products as reported by IDFA (Rutherford 2006). In recent years the growth rate of drinkable yogurts and smoothies has outpaced spoonable yogurt, albeit from a smaller base, with sales doubling in the years from 2002 to 2005. Marketers have blurred the differences between drinkable yogurts, yogurt smoothies, and smoothies. No standard of identity exists for smoothies and some are based on soy or dairy proteins and may not be fermented. Since there is no requirement for the amount of yogurt in a smoothie, there is a wide variation from products that meet the standard of identity for yogurt to products made with less than 2% yogurt. Consumers and manufacturers can also be confused about the yogurt content in a drinkable yogurt based on the standard of identity for yogurt (21 CFR 131.200). This standard calls for a minimum of 8.25% milk solids nonfat before the addition of bulky flavor ingredients, but no limit is specified on how much flavoring ingredients can be added. By specifying minimums of milk solids and milkfat after bulky flavor addition, ice cream standards of identity (21 CFR 135.110) limit the amount of bulky flavors to 20%. Therefore a manufacture adding 50% juice to a yogurt base might consider labeling the product as drinkable yogurt. The application and wording of this regulation is unclear. Drinkable yogurts also have a wide range of viscosities, flavors, and sweetness. Some consumers are looking for a low-viscosity beverage while others are looking for something more substantial as a significant component of a meal. In both of these cases, as well as smoothies made with soy or dairy proteins, the two requirements of hydrocolloids are the same—prevent proteins from precipitating and impart the desired

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viscosity. Protein stabilization is dependent on heating profile, protein source (casein to whey ratio, soy), protein content, total solids, and viscosity. It is easier to keep protein from precipitating, or fat from creaming, by raising viscosity. This relationship is well understood and described by Stoke’s law v p = 2r 2 g(ρ p − ρ f )/9µ where vp is the particle velocity, r is the radius of the particle, g is the gravitation acceleration, ρp is the density of the particle, ρf is the density of the continuous phase, and µ is the viscosity of the continuous phase. Particle suspension can be enhanced by decreasing the particle radius, altering the density of either the continuous or discontinuous phase, and increasing the viscosity. In drinkable yogurt, the particle size can be controlled by limiting protein denaturation and aggregation by reducing the time and temperature of pasteurization. Low-viscosity drinkable yogurts can be made by pasteurizing at 180◦ F for 30 seconds. The primary method of controlling protein aggregation in acid yogurts and smoothies is the combination of high methoxyl (HM) pectin, shear, and pH. Below their isoelectric point of 4.6, milk proteins have a net positive charge which increases as the pH is decreased. HM pectin has an isoelectric pH of ∼3.6 and a net negative charge above this pH. Optimal protein stabilization is obtained by culturing milk, adding pectin, and homogenizing. Pectin can be added with a flavored juice slurry, which includes pectin, juice, sweeteners, other stabilizers, and flavors that were pasteurized separately from the dairy base. Protein stability is highest from pH 3.8 to 4.1 and is imparted by the electrostatic interaction of the protein and pectin combined with steric hindrance. In order to limit acidic flavor notes manufacturer’s balance stability from lower pH with better flavor at pH’s closer to 4.6. Most drinkable yogurts are made at pH 4.1–4.4. Homogenization is not practical postpasteurization in many plants so the shear is applied by other means such as back pressure valves. Air should not be incorporated as this can lead to separation. Protein aggregate size is also dependent on the protein content and the amount of sugar. Sugar has a protective effect on proteins during heating and fewer problems with aggregation are observed in formulas with higher amounts of added sugars and lower total protein. Formulas with higher sugar content also have less water that needs to be stabilized.

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A problem related to protein aggregation is clear liquid separation. This is common in unstabilized, unsweetened yogurt formulas as the protein aggregates and displaces water. Separation is often seen in yogurt that is not properly stabilized and processed. This serum separation is harmless, but a consumer often thinks that separated product is spoiled. In order to minimize the economic impact, stabilizers are added to control syneresis. Gelatin is effective at preventing separation in drinkable yogurts and buttermilks. Stability against separation in the white mass is also enhanced by the use of an exopolysaccharide producing culture. The ingredients for stabilizing protein also provide viscosity. Additional viscosity can be added by using any hydrocolloid that will withstand the processing and pH of the drinkable yogurt. Modified food starch, locust bean gum, cellulose gum, carrageenan, and guar gum are commonly used. The parameters used for starch selection in drinkable yogurts are similar to spoonable yogurts as both undergo pasteurization and homogenization. Natural and organic drinkable yogurts are made with HM pectin in combination with galactomannans (guar gum and locust bean gum), and/or native starch. Higher levels of native starch are needed compared to modified starch as the native starch is broken down more easily by heat, shear, and acidity than a cross-linked starch. Ingredient statements of drinkable yogurts and spoonable yogurts are similar especially in cases where modified starch and gelatin are used in the white mass. Pectin can be used in combination with modified food starch in fruit preparations for spoonable yogurts and in the white mass for drinkable yogurts. Table 7.1 shows formula and processing differences for drinkable and spoonable yogurts. Culture strain selection may or may not be the same for both types of yogurt. Smoothie formulation and processing varies widely, especially in food service operations. Many of these smoothies are made on site after the customer orders and may include fruit, ice, soft serve frozen dessert, a smoothie base, flavoring syrups, protein powders, vitamin and mineral premixes, etc. Some of these components may include hydrocolloids for viscosity or stability of one of the components such as the soft serve mix. Stabilization of proteins is not a concern since the product shelf life is less than 1 hour for a product sold for immediate consumption. Retail products with a longer shelf life require more stabilization, which can range from systems similar to those used in drinkable yogurt to a thickened juice base if the product does not contain any protein.

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Table 7.1. Formulation and processing parameters for drinkable and spoonable lowfat yogurts.

White mass MSNF Milkfat Sweetener Modified starch Gelatin Pectin

Pasteurization Homogenization Bulky flavor

Postculture shear

Spoonable Yogurt

Drinkable Yogurt

8.25% minimum 1% 5–10% 1–3% 0.3–0.5% <0.5% LM pectin in white mass HM or LM in fruit prep 180–200◦ F for 3–10 minutes Varies with fat content 0 psi in nonfat to 2000 psi 5–15% high viscosity stabilized fruit preparation Pumping with moderate shear

8.25% minimum 1% 5–10% 0–1% <0.3%, if used 0.4–0.75% HM pectin, added to juice base 180–190◦ F for less than 1 minute Varies with fat content 0 psi in nonfat to 2000 psi 10–30% low viscosity juice with pectin added for protein stability High shear, homogenization optimal

Cultured Buttermilk Cultured buttermilk is made from the culturing of fresh milk and can have a fat content from 0 to 3.5%. The liquid by-product from the churning of cream to make butter is also called buttermilk. This ingredient can be dried and the powder is used as an alternative to nonfat milk solids in bakery applications and ice cream and is sometimes referred to as sweet cream buttermilk. This product could be cultured, but this in not currently practiced on a commercial scale. Cultured buttermilk is also used in baking to provide flavor, acidity, and textural enhancement. It is also consumed as a beverage with the largest market in the southeastern United States. In the remainder of this section, buttermilk is used interchangeably for cultured buttermilk. Buttermilk is listed under the standard of identity for cultured milk, 21CFR 131.112, and stabilizers are optional ingredients. “Buttermilk for baking” is defined in the United States milk classification pricing by its starch content, which must be in excess of 2% of the total solids in

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Table 7.2. Example formulas of cultured lowfat buttermilk and cultured buttermilk.

Milkfat Milksolids nonfat Starch Galactomannans Carrageenan Emulsifiers Sodium citrate Sodium chloride

Cultured Lowfat Buttermilk (%)

Cultured Buttermilk (%)

1.0 8.5 0–0.4 0–0.15 0–0.05 0–0.2 0.15 0.2

3.4 8.5 0–0.3 0–0.1 0–0.05 0–0.2 0.15 0.2

the product. Formulas for 1% fat buttermilk and whole milk buttermilk are shown in Table 7.2. If the starch content in a formula is greater than 0.2%, the formula could also be used to make buttermilk for baking. Traditional buttermilk was made from whole milk with the addition of salt and sodium citrate. The milk was vat pasteurized, cooled, inoculated, and fermented. After the target pH was reached, the coagulum was broken by mixing and the product pumped with shear and packaged. In some of these products, stabilization was not needed because of the combination of creaminess from the fat and viscosity from protein denaturation and polysaccharide producing cultures. While some plants still employ vats pasteurization today, most utilize HTST processing and produce nonfat and lowfat cultured buttermilk in addition to the full fat product. Stabilizers enable the processor to make a product with the same viscosity using a continuous lower heat process and can enhance the creaminess of reduced fat and nonfat buttermilk. Since its primary use is as a beverage, the viscosity of buttermilk is low. Shear is employed after processing to reduce the viscosity of the buttermilk. Air must not be incorporated at this step or separation can occur. This step also smooths the product to remove lumps. If a stabilizer is used, the application rate is typically 0.5% or less. Commonly used ingredients are modified food starch, locust bean gum, gelatin, and a milk reactive carrageenan. Emulsifiers are utilized by some manufacturers. Unmodified starches from corn and/or tapioca are used in products marketed with a cleaner label. Related cultured milk products,

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such as sweet acidophilus milk and kefir, are made in a manner similar to cultured buttermilk but utilize specific cultures.

Sour Cream Sour cream and cultured buttermilk are both fermented with similar lactic cultures and fermentation conditions. The obvious differences are in the fat content and the finished product viscosity. Other differences are the lower moisture content and higher stabilizer content in sour cream. Standards of identity for sour cream in the United States can be found in 21 CFR 131.160; the Canadian sour cream regulations are under B.08.077 of the food and drug regulations. The minimum required milkfat content for sour cream is 18% in the United States and 14% in Canada. Canadian regulations limit starch to 1%, gelatin and hydrocolloids to 0.5% total, mono- and diglycerides to 0.3%, and disodium phosphate to 0.05%. The standard of identity for sour cream in the United States has no specific limits on stabilizing ingredients other than good manufacturing practices. Both countries allow the use of specific proteolytic enzymes that also contribute to a firmer product. Cultured dairy products traditionally did not use stabilizing ingredients, but most products today contain stabilizers. This is due to the economic benefits of using stabilizers, the need to meet customer demand for thicker products, and the need for stability in longer shelf-life products. Thicker products are preferred for their creaminess and ability to retain viscosity when mixed into dips or cooking applications in home use and food service operations. Sour cream production begins with standardization of milk and cream, addition of stabilizer followed by pasteurization, homogenization, inoculation, incubation, and packaging. Like yogurt, sour cream can be made by vat set or cup set procedures. Pasteurization times and temperatures are similar to those for yogurt where it is desirable to denature whey proteins. Homogenization pressures vary amongst processors, and can be the highest pressures used among cultured dairy products. The emulsion surface area is coated with protein and the interaction of the interfacial proteins with other components in the sour cream give the product a thicker texture. United States standards of identity allow the addition of sodium caseinate, a milk protein with improved surfactant properties.

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Hydrocolloids function in sour cream by binding water, interacting with dairy proteins, or a combination of these. Modified food starch, gelatin, locust bean gum, guar gum, and carrageenan are commonly used stabilizing ingredients. Gelatin and the combination of locust bean gum and carrageenan are gelling agents often used in sour cream. Other gelling agents like pectin are allowed, but not typically used. Modified starches from dent corn have some set characteristics, and these can make up a portion of the stabilization system. Modified waxy cornstarch is also used in sour creams to bind water and build viscosity. Starch usage rates in sour cream are similar to spoonable yogurts, 1–3%, making starch a major contributor to sour cream rheology. Carrageenan with high milk protein reactivity builds body in sour cream at low use levels. Too much of this type of carrageenan will result in a curdy sour cream. Higher pasteurization temperatures and longer hold times increase interactions between carrageenan and milk protein. Other ingredients that affect the reactivity of milk protein are protein level, whey to casein ratio, coagulating enzymes, and mineral content. Shear after culturing results in thicker, smoother sour creams, contrary to yogurts which become thinner and smoother. The viscosity of sour cream can be increased by more than 30% compared to product made with lower shear. Shear devices used include pumps, screens, bell flow valves, and back pressure valves. The energy added at this step increases the emulsion surface area and alters ingredients interactions and structures. Within limits, these changes can have a greater effect on sour cream texture than factors causing lower viscosity, such as the shear breakdown of starch or culture produced polysaccharides. Cup set sour cream cannot be sheared in the same manner as vat set sour cream. The texture of cup set sour cream can be enhanced by the use of polysaccharide producing cultures. A number of reduced fat sour creams are marketed in North America. Fat contents range from 9% in light sour cream for the U.S. market to 5% in Canada, and nonfat in both countries. Flavor and texture in the lowfat products deviate further from the full fat standard as fat content is decreased. Lower fat sour creams have less interfacial surface area and more water to bind. Higher levels of stabilizers are used to the bind water, increase viscosity, and enhance creaminess. Fat replacement remains an area for companies to innovate and for dairies to differentiate their products over their competitors. These challenges are especially

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Table 7.3. Example formulas for nonfat, light, and regular sour cream.

Milkfat Milksolids nonfat Starch Galactomannans Carrageenan Emulsifiers Gelatin Sodium phosphates Sodium citrate

Nonfat Sour Cream (%)

Light Sour Cream (%)

Sour Cream (%)

<1 10–12 2–4 0.1–0.4 0–0.1 0.1–0.3 0.2–0.4 0–0.2 0.1

9 9–11 0–3 0–0.4 0–0.05 0–0.2 0–0.3 0–0.2 0.1

18 8–10 0–2 0–0.4 0–0.05 0–0.2 0–0.3 0–0.2 0.1

evident in nonfat sour creams whose rheology is often similar to nonfat plain yogurt. Sour cream formulas with varying fat levels are shown in Table 7.3. Sour cream products can be made by the direct addition of acid rather than the action of lactic acid bacteria. Stabilizing ingredients allowed in direct set sour creams made in the United States are the same per 21 CFR 131.162. Direct set products made without stabilizer have lower viscosity and flavor than a cultured product with the same composition. To compensate for these differences, flavors, such as starter distillate or diacetyl, are added and higher levels of stabilizer are used to increase viscosity. Advantages for direct set processing are continuous manufacturing, less equipment usage, no culturing time (typically 12–16 hours), not subject to bacteriophage, no variation due to culture strain growth rates, and fewer changes during shelf life. Cottage Cheese Cottage cheese is a soft, unripened cheese consisting of curds and a liquid dressing. The typical milkfat levels are 4%, 2%, and nonfat. All varieties of cottage cheese begin with curds made by the acidification of skim milk via the action of lactic acid bacteria or direct acidification. The curds are cut, cooked, drained, and then dressed unless a dry curd cottage cheese is being produced. Cottage cheese is sold as large curd or

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small curd. Curd manufacture is a delicate process requiring consistent practices to minimize yield loss. Factors affecting the curd yield are incoming milk quality, pasteurization time and temperature, pH at curd cut, curd size, acid addition, cooking conditions, and use of coagulant. The standard of identity for dry curd cottage cheese in the United States is found in 21 CFR 133.129. Stabilizers are not allowed under this standard, but most cottage cheese is dressed. Dressed cottage cheese is defined under 21 CFR 133.128, which allows for the inclusion of safe and suitable ingredients such as stabilizers. Canadian regulations allow up to 0.5% stabilizer in cottage cheese (B.08.51); stabilizing, gelling, emulsifying, and thickening agents are allowed in creamed cottage cheese (B.08.52) with no level specified. Dressing is formulated, pasteurized, and homogenized separately from the curd. Stabilizers and emulsifiers are added to the dressing with other ingredients including salt and cream. Fat and salt levels of the finished cottage cheese are determined by the dressing composition. Cottage cheese contains 40–60% curd; and if a finished fat content of 4% is desired, the fat content of the dressing should be approximately 8%. If the salt content of a finished cottage cheese is 1%, the salt content in the dressing should be about 2%. The high salt content of the salt in the dressing is a factor in determining which stabilizers are used. Because of its high salt tolerance compared to other food hydrocolloids, xanthan gum is commonly used in cottage cheese dressing in combination with locust bean gum and/or guar gum. This is to take advantage of the synergies between xanthan gum and galactomannans. Some dressings utilize carrageenan, and extracts with higher salt tolerance are chosen. Starches, pectin, and gelatin are not typically used in cottage cheese. Emulsifiers are traditionally added to cottage cheese dressing and help to minimize air entrapment during processing. Lower fat dressing formulas are similar to the full fat versions with added levels of stabilizers. Stabilizer levels in 4% fat cottage cheese (8% fat in dressing) are less than 0.5%. The higher hydrocolloid level in nonfat dressings can be troublesome during processing with high viscosity increasing the likelihood of equipment downtime. Other ingredients added to dressing are nonfat milk and whey solids. Some dressing formulations include cultured nonfat milk or acid whey to impart distinctive flavor notes. Cottage cheese dressing formulas for 4% fat and nonfat cottage cheese are shown in Table 7.4.

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Table 7.4. Example formulas for cottage cheese dressing of nonfat and 4% fat cottage cheese.

Milkfat Milksolids nonfat Xanthan gum Galactomannans Carrageenan Emulsifiers Sodium chloride

Nonfat Cottage Cheese (%)

4% Fat Cottage Cheese (%)

<1 12–15 0.05–0.2 0.2–0.4 0–0.05 0.1–0.2 2

8–10 8–10 0.05–0.2 0.2–0.3 0–0.05 0.1–0.3 2

Cream Cheese and Neufchatel Cheese Cream cheese and Neufchatel cheese are also soft unripened cheeses. Records on Neufchatel cheese date back to the eleventh century in France when it was prepared in a variety of shapes. Traditionally the cheese had a soft crumbly rind and a creamy interior. Cream cheese was invented in 1872 in Chester, NY, as a creamier and richer cheese than others on the market (http://www.kraft.com/archives/ brands/brands cream.html). The standard of identity for these cheeses are similar, and some reduced fat cream cheese is marketed as Neufchatel cheese as it meets the Neufchatel standard. Cream cheese regulations in the United States (21 CFR 133.133) specify a minimum fat content of 33%, maximum moisture of 55%, and no more than 0.5% stabilizer. Canadian cream cheese standards (B.08.037) have a minimum fat content of 26%, maximum 60% moisture, and no more than 0.5% of specific hydrocolloids. Neufchatel cheese in Canada (B.08.033) allows no stabilizers, a minimum of 20% milkfat, and no more than 60% moisture. U.S. Neufchatel standards (21 CFR 133.162) specify 20–33% milkfat, a maximum moisture content of 65%, and no more than 0.5% stabilizing ingredients. Given the long history of these cheeses, both the production methods and ingredients have changed. Modern production methods incorporate continuous pasteurization, homogenization, mechanical separators, and stabilizers, including xanthan gum that was first allowed in foods less than 40 years ago. The most commonly used stabilizers in cream cheese

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today are locust bean gum, xanthan gum, and guar gum. Locust bean gum and xanthan are the most effective combination. Higher levels of guar gum are used when locust bean gum availability decreases or price increases, as both are synergistic with xanthan gum. Tara gum is another galactomannan that is sometimes used in cream cheese. Limits on the number of dark specks are included in specifications for locust bean gum in cream cheese to prevent a visual defect in the finished product. Neufchatel cheeses made in the United States also have locust bean gum, xanthan, and guar gum. This is especially true if the Neufchatel is marketed as a reduced fat version of a cream cheese. One of the complaints about butter and cream cheese is their lack of spreadability at refrigerated temperatures. Whipped cream cheese has been marketed since the 1950s, but this solution was not ideal. In the early 1980s a soft cream cheese that may employ the use of different processing parameters was introduced on the market (Davis 1986). Cream cheese with softer texture can also be produced by direct acidification methods. Directly acidified products do not require a whey drainage step and can be formulated and processed to give a soft or a firm texture. In order for these products to be called cream cheese, they must meet the compositional standards established by the government. All of the examples discussed above are produced utilizing guar gum, locust bean gum, and xanthan gum as the nondairy stabilizing ingredients. Formulations for cheese products are not included as processing steps such as separation and whey drainage effects when stabilizing ingredients can be added and at what level.

Nonstandardized Soft Unripened Cheeses There are a number of soft cheeses produced in North America that do not have a standard of identity. Ricotta and Hispanic style cheeses like queso blanco and panella are the most widely sold. Ricotta cheese is made with varying levels of fat and casein to whey protein ratios. Ricotta made with lower fat and higher amounts of whey protein has a softer texture that can be improved by the addition of hydrocolloids. Carrageenan, locust bean gum, guar gum, and xanthan gum are commonly used in ricotta. Heat stability is important to cheeses used in cooking, as is the case for ricotta (pasta fillings) and Hispanic style cheeses.

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In cases where these cheeses are not designed to melt, modified food starches can be used in combination with hydrocolloids.

Process Cheeses Products Process cheese and its related products are characterized by standards of identity and their similar processing. These cheeses are not cultured, but represent one of the largest outlets for cultured natural cheese products. Cheeses vary in their ability to melt as can be observed by preparing a pizza with a mild Cheddar cheese. Historically the melting properties of cheese were improved by adding wine to cheese to make fondues. It was learned that emulsifying salts present in wine combined with heat and agitation were responsible for this and the process cheese industry grew from this discovery. Standards of identity for process cheese products specify the minimum cheese content, minimum milkfat, maximum moisture, and allowed ingredients. Although the standard of identity for pasteurized process cheese in the United States does not have a specific minimum cheese content (21 CFR 133.169), it allows very few additional ingredients, so the effective minimum cheese content is approximately 80%. This standard does not allow for the addition of any hydrocolloids. Process cheese standards vary by country and within the past decade regulations in some countries were revised to allow the use of hydrocolloids. Carrageenan use has increased dramatically in these products, as European processors are able to maintain cheese firmness and melt at a lower cost. Pasteurized process cheese food (21 CFR 133.173) has a minimum cheese content of 51% and allows more dairy-based ingredients than are in pasteurized process cheese, but still excludes the use of hydrocolloids. Several years ago a process cheese food that contained added calcium and milk protein concentrate was on the market. The company producing this cheese changed the name of the food to a “pasteurized process cheese product.” Other companies have adopted this nonstandardized name, and today hydrocolloids are found in individually wrapped slices. As was evidenced in European process cheese, carrageenan is also effective in this application due to its milk protein reactivity and gelling properties. Modified food starch is used in some pasteurized process cheese product, and its usage should increase if

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pricing of dairy powders like whey remains significantly more expensive than starchy alternatives. Pasteurized process cheese spread (21 CFR 133.179) contains a minimum of 51% cheese and moisture content between 44 and 60%. This standard allows for the addition of up to 0.8% of a range of hydrocolloids including guar gum, carrageenan, and gelatin. Hydrocolloids help tie up the added water and control the viscosity in cheese spreads, and carrageenan is the most commonly used. Cold pack cheese food (21 CFR 133.124) is another spreadable cheese product that allows up to 0.3% of guar gum and/or xanthan gum. These gums are selected for their cold solubility as this cheese is made without heating. Cheese sauces encompass a variety of products made with cheese for which there is no standard of identity. Since there is no minimum cheese requirement, there are many products made with less than 15% cheese. The high moisture content in cheese sauces cannot be stabilized by cheese protein alone, as there is not adequate protein in most sauces to achieve the desired viscosity. This is accomplished with a variety of hydrocolloids with modified food starch being the most widely used. Cheese sauces are shipped and stored at ambient conditions and can have a shelf life up to 1 year. Products used in food service are subject to reheating and held in warmers for several hours. Nacho cheese sauces are dispensed, and xanthan gum is well-suited for this application because of its stability under harsh conditions combined with shear thinning during pumping and cling on the chips as measured by yield stress. Formulas for various process cheese products are shown in Table 7.5.

Other Cheeses Varieties There are numerous varieties of cheeses produced globally; and tastes, textures, and regulations vary by country and type. In the United States there are over 50 standards of identity for cheese varieties. In the United States the largest selling cheese types are mozzarella and Cheddar. According to the USDA production data (USDA 2007), these two cheese types each represented one-third of the total U.S. cheese production, exclusive of cottage cheese. Food manufactures are large users of these cheeses, as mozzarella is used in pizzas and Cheddar is used in process cheese products and cheese powders. Regulations in the United States

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Table 7.5. Example formulas of pasteurized process cheese spread, cold pack cheese food, and nacho cheese sauce.

Cheese Added milkfat Vegetable lipids NFDM/whey Galactomannans Carrageenan Xanthan gum Gelatin Modified starch Emulsifying salts Sodium chloride Flavor ingredients

Process Spread (%)

Cold Pack Cheese Food (%)

Nacho Cheese Sauce (%)

>51 5–10 Not used 2–4 0–0.4 0–0.1 0–0.3 0–0.4 Not used 2–3 0.5–1.5 0.5–2

>51 8–12 Not used 15–20 0–0.3 (guar) Not used 0–0.3 Not used Not used Not used 0.5–1.5 0.5–2

10–20 0 10–20 4–10 0–0.5 0–0.1 0–0.2 0–0.3 3–5 1–4 0.5–2.0 0.5–2

NFDM, nonfat dry milk.

and Canada do not allow the use of hydrocolloids in most standard of identity cheeses. An exception is the use of cellulose, microcrystralline cellulose, and starch as anticaking agents in grated or shredded cheeses. Hydrocolloids are also used in reduced fat cheeses in the United States. Cheese manufactures have sought to improve the nutritional properties of cheese as they have a high percentage of calories from fat and saturated fats. Some success has been achieved in cheeses with 25–40% less fat without the use of nontraditional cheese ingredients. These cheeses have higher protein, moisture, and typically utilize adjunct cultures. Drake et al. (1996) evaluated commercial fat mimetics in Cheddar cheeses with a 60% reduction in fat. One of the fat mimetics tested was microcrystalline cellulose. In this study, all of the reduced fat cheeses were inferior to a full fat control in both flavor and texture with firmness and rubberiness both being higher in the lowfat cheeses. Lowfat cheese made with microcrystalline cellulose had a higher moisture content and yield than the lowfat control. This resulted in a cheese that was less rubbery than the lowfat control indicating a potential role for hydrocolloids in both yield enhancement and textural improvement. Additional research in this area is needed to improve the texture and flavor of lowfat cheeses with higher levels of fat removed.

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In addition to the variety of natural cheese types, there are cheese alternatives that utilize nondairy ingredients. These are called imitation cheese, analogue cheese, substitute cheese, or are marketed under a fanciful name. Some of these have their own requirements such as substitute mozzarella which has vegetable fat substituted for milk fat but must meet other nutritional requirements. Most do not fall under regulations and their ingredients are determined by their desired functionality, texture, and flavor. Alternatives for mozzarella cheese are considered the most challenging because they require good firmness for shredding, need to melt on pizza, and provide characteristic stretch. Since the milkfat has been replaced with vegetable lipids, the highest cost contributors to these products are milk proteins. Traditionally rennet casein has been used at levels up to 22% protein in the finished cheese. Numerous formulas and procedures have been evaluated globally to reduce the protein level with starch and carrageenan being the stabilizing ingredients most often used. Carpenter et al. (1998) describe imitation cheeses with less than 2% protein that contain 3–10% modified starch and 1–5% of a mixture of xanthan gum and locust bean gum. This level and combination of hydrocolloids forms a gel which, according to one of the patent examples, melts on heating. Agar is known for its thermoreversible gelling and is a component in low protein cheese analogs disclosed by Jacobson and Schallow (2005). Carrageenan, microcrystalline cellulose, and pectin are also present in the example formulation of this patent. The use of hydrocolloids in natural and analog cheeses is dependent on the processing and desired attributes. Individually wrapped cheese slices are cooled quickly and segregated from other slices with a plastic film. This film also provides support to the cooling cheese. Cheese slices made on a chill roll are also cooled quickly, but need more strength to withstand the cutting and handling of a slice-on-slice operation. Separation from other cheeses is a customer consideration in these products as well as in shredded cheeses. Shredded cheese should not clump at or during shredding or storage. Some cheeses are formulated to melt at higher temperatures or not to melt at all if individual cheese piece identity is desired in a cheese sauce. Hydrocolloids can be used to raise the viscosity of a cheese mixture or, in the case of hydroxypropylmethylcellulose, to gel during heating and thin after cooling. A food scientist with sufficient knowledge of hydrocolloid rheology and their interactions with other ingredients can utilize the unique benefits of

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these ingredients to formulate cheese products with the desired texture under a variety of conditions.

References Carpenter R.N., Finnie K.J., and Olsen R.L. 1998. Imitation cheese composition and products containing starch. US patent #5,807,601. Davis L.L. 1986. Soft cream cheese product. US patent #4,597,971. Drake M.A., Boylston T.D., and Swanson B.G. 1996. Fat mimetics in low-fat Cheddar cheese. J Food Sci, 61:1267. Jacobson M.R. and Schallow S.M. 2005. Imitation cheese compositions for use in the manufacture of cheese loaves, slices and the like, and method of producing such compositions. US patent #6,905,721. Rutherford J. 2006. Cultured Dairy Products: Where we are . . . where we are going. Presented at IDFA cultured product conference, May 23–24, Minneapolis, Minnesota. USDA 1997. Guidance for industry: The sourcing and processing of gelatin to reduce the potential risk posed by bovine spongiform encephalopathy (BSE) in FDAregulated products for human use. http://www.fda.gov/RegulatoryInformation/ Guidances/ucm125182.htm. USDA 2007. Dairy Products 2006 Summary, National Agricultural Statistics Service. Washington, DC.

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Chapter 8 Hydrocolloids in Restructured Foods Ian Challen and Ralph Moorhouse

Introduction Restructured foods are a key facet of the food industry involving a complex “assembly” of raw material and ingredients and a number of texturing and structuring processes. It should be emphasized that restructured foods differ from structured foods (e.g., ice creams, sauces, bakery products) in that a key ingredient is a natural raw material (e.g., fruit) that is reformulated and the end product may then be further processed. That said, many of the techniques and ingredients used in structured and restructured foods are common. Simply put, the goal with restructured foods is to take a natural ingredient (e.g., fruits, vegetables, fish or meat) apart, then reassemble it to give it improved and consistent properties while maintaining its appearance, texture, and flavor. Of course, nothing is as simple as it sounds, and the purpose of this chapter is to review the advantages of restructured foods (e.g., enhanced properties, efficient utilization of raw materials), discuss the criteria for raw material selection, discuss the stabilizers used, and how these stabilizers are best utilized for given applications. Finally, the cost–benefit aspect will be discussed.

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Ancient History Perhaps the earliest form of restructured food is a material known as “sahardi” (probably named after the Sahara desert) or “fruit roll” as it is known in the United States. This dehydrated foodstuff is believed to have originated in the deserts of North Africa many centuries ago. Indigenous ripe fruit such as apricots were beaten to a pulp with a stone on a flat rock, spread out into a thin sheet, and allowed to dry in the sun. Once dry, the film would be rolled up and taken by the camel driver on his journey. It is possible that the natural pectin in the fruit coupled with the high sugar concentration caused by the evaporation process helped to hold the product together—rather like a modern day jam. Since the product was acidic and dry, it would have a low water activity (aw ) and moisture content and had, therefore, a long shelf life. Both alginates and low methoxyl pectins react with calcium ions to form gels. However, since the vast majority of restructured food work has been done with alginates, they have become the gelling agents of choice for these applications. In this chapter, it is only possible to give a brief overview or snapshot of parts of this fascinating but relatively underexploited technology. As we progress, you will begin to understand the enthusiasm that we have for the subject and realize that, with a little innovation and creativity, much more can be accomplished to the great benefit of the consumer. Definitions For the purpose of this discussion, the following definitions will be used: 1. Structured food: A structured food has no key ingredients that identify the product. For example, ice cream is made with a large variety of ingredients none of which alone describes or identifies the product. Often the product does not have a defined shape—it takes the shape of the container in which it is deposited. Similarly salad dressing has no shape per se—it has a texture but not a shape. However, the material must comply with existing legislation and any Standard of Identity regarding additives.

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2. Restructured food: In contrast, a restructured food will contain a natural raw material as one of its key ingredients. Often, the named raw material will appear as part of the product name or descriptor, for example, Onion Rings contain real onions. A restructured food is held together with a gelling system so that it can stand up under its own weight. It does not need to be in a container for structural reasons but may be in one for other purposes (packaging, marketing, preservation, transport, etc.). Finally, a restructured food may be designed for further processing, for example, pasteurization—a procedure that the natural product might not be able to withstand. One example of this is a piece of peach. Such a piece would be reduced to mush or pulp by a traditional pasteurization treatment, while a piece of peach that has been restructured can be made not only to withstand such a process but to benefit from it. A restructured foodstuff must also comply with existing legislation and any Standard of Identity regarding additives. Some examples of the differences between structured and restructured foods are shown in Table 8.1. With products like ice cream, sauces, and dressings, there are no key criteria that the product must comply with apart from any existing legislation and/or Standard of Identity. In contrast, a restructured food product must contain a named ingredient as one of the key criteria. Thus, a restructured fruit product referred to as “peach” on its label must contain some peach in it, and a restructured vegetable referred to “tomato” must contain some tomato Table 8.1. Examples of structured and restructured foods. Key Criteria

Compliance

Structured food Ice cream Sauces

None None

Must comply with legislation and/or Standard of Identity

Restructured food Fruit Vegetables

E.g., peach E.g., tomato

Must comply with additive legislation: 21 CFR 184.1724 E.401

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in it. Such products must also comply with any relevant legislation including any additive legislation pertaining to it—the CFR number in the United States and an E. number in various countries in Europe. Sodium alginate, the gelling agent of choice for restructuring purposes, is included in a list of stabilizers that are generally recognized as safe (GRAS) under 21 CFR 184.1724 in the United States and as E.401 within the European Community. The act of restructuring is not merely an end in itself. It can be used to good effect to provide control of the shape, size, and weight of the final product—an invaluable asset for portion control. In addition, the calorific content of each portion can be carefully controlled and, therefore, guaranteed. This is especially valuable for restructured materials such as meat products and for those designed for use in a strict calorie diet. The taste of the finished product can also be controlled so that all portions derived from the same batch of starting material are exactly the same. Similarly, the final texture can be controlled and delivered each time. Essentially, the act of restructuring enables us to take a food raw material and make it do something beyond that which it does normally or naturally. In essence, restructuring confers additional and/or different properties to the product. The act of restructuring permits certain features to be designed and built into a product to enhance various natural characteristics—characteristics that the original raw material did not possess. These new features then enable the restructured product to be used in applications where they are not traditionally used because they would be deficient in some aspect. Other design features could include making the product stable to a heat treatment needed for preservation to give it a certain shelf life—a feature that the original raw material might not have. Examples of this are fruit pies that retain their texture during baking, dehydrated fruit pieces used in fruit soups and cakes, fruit pieces in sauce that retain their structural integrity, canned pet food, etc. Restructured products can also be designed to withstand different storage regimes. Thus, restructured pimiento strip used to stuff olives can be in-can pasteurized in an acid/calcium medium and still retain the required textural properties. Fruit pieces for inclusion in ice cream

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or breakfast bars also fall into this category as do materials that are designed for individual quick frozen (IQF) treatment (e.g., fish). Products can also be designed to be dehydrated and subsequently rehydrated under specified conditions. For example, restructured meat and vegetable pieces can be made wet, dehydrated under given conditions to give the required shelf life, and then rehydrated in hot or boiling water when required. Frequently the rehydration medium is antagonistic to the rehydration process because it is either acidic or contains a lot of ions (usually in the form of salt or monosodium glutamate (MSG). For example, restructuring permits one to produce a food item to be used in circumstances where it is either not traditionally used or where it would not function optimally. A typical example of this is a filling for fruit pies. Unless the fruit preparation is properly formulated, the fruit leaks out of the pie during the baking process making it sticky, unappetizing, and unacceptable. The fruit looses its normal texture, becoming softer or mushy during cooking. Using a restructured fruit and modified filling matrix can improve the baked fruit texture, eliminating boil out and improving the fruit texture and flavor. The fruit itself looses less volume during baking; consequently, the pie has a better overall quality and, frequently, a longer shelf life. Another example of this approach is fruit pieces for inclusion into ice cream. Such pieces containing a higher than normal level of sugar can be designed and restructured so that they can be eaten at typical ice cream–eating temperature. Thus there is no danger of breaking one’s teeth on hard fruit particles when the ice cream is eaten. Such pieces can also be colored and flavored for optimal organoleptic properties. A spin-off of this idea is to make a structured fruit coat to surround popsicles or other stick products with small fruit like berries that are stuck on the outside of these products with ice. Perhaps one could design a popsicle that had both soft fruit pieces inside and berrylike spheres on the outside! Similarly, high solids fruit pieces can be made for inclusion into snack, breakfast, and granola-type bars. Such pieces may contain real fruit, fruit pulp or puree, fruit concentrate with added fibers for improved texture, or just fruit flavor and a suitable color—provided, of course, that these materials conform to the label declaration and the permitted additives list.

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Basically, the restructuring process is made up of three parts: 1. A given raw material is disassembled and cut into smaller pieces of similar size. This may be done by cutting it into pieces—such as for meat, by comminuting it into a puree or pulp, or by mincing it. In each case, the size of the disassembled pieces will have a direct influence on some aspect of the final product. Restructured pureed fruit will generate a totally different texture than comminuted, minced, or chopped meat. Similarly, each of the different processes used to disassemble meat will result in restructured products having very different textural and organoleptic properties. 2. The disassembled material is reassembled by intimately mixing it with sodium alginate or a solution of sodium alginate. It is essential that the alginate is hydrated to obtain maximum binding from the gel to be formed. 3. The mixture is then subjected to a treatment with a calcium salt. The formulation is designed so that the calcium in the salt is released in a controlled way and reacts with the alginate to form a calcium alginate gel. It is this gel that holds the new material together. The reaction between the alginate and the calcium ions occurs at ambient temperature and pressure. Choice of Gelling Agent Over the past 40–50 years, many hydrocolloids and hydrocolloid combinations have been evaluated as the gelling agents or structure-formers for restructured products. Eventually, sodium alginate and low methoxyl pectin became the favorites with alginate finally taking the leading role. This was because the chemistry of alginate gelation is relatively simple and well-understood and a large variety of alginates (differentiated by chemical structure, rheology, mesh size, etc.) was readily available to suit different needs and applications. The rate of the gelling reaction can be controlled in various ways so that products can be mixed and deposited before the onset of gelation, thereby allowing the alginate gel to set in shear-free conditions—a necessity if a coherent gel is to be formed. In addition, since alginate gels can be made over the pH range from 3.8 to >7, they encompass the pH range of many typical food product pHs.

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Alginates: Source, Chemistry, and Properties Alginates and alginic acid are polysaccharides (or polyuronides), which form the major structural carbohydrate in brown seaweeds (the Phaeophyceae). It is believed that alginates provide rigidity and flexibility to the seaweed plant, so that it can withstand the constant movement of the sea, but also provide an ion-exchange mechanism, which allows the seaweed to extract essential nutrients from seawater. Alginates, therefore, exist as a mixed salt in the parent seaweed. Once extracted and converted to a specific salt form, alginates are supplied as dry powders. Monovalent salts, such as sodium, potassium, and ammonium alginate, hydrate in water to produce viscous solutions. Most divalent metal alginate salts like calcium alginate are insoluble. However, magnesium alginate is anomalous in that, being the salt of a divalent metal, it is soluble in water; and, like the monovalent salt varieties, it produces viscous aqueous solutions. Each of these seaweed species produces its own characteristic type of alginate, according to the molecular structure, on the basis of the ratio of mannuronic (M) and guluronic (G) acid and the way these acids are arranged in the molecule. Typical structures for M, G, and alternating sequences are shown in Figure 8.1. COOH

COOH O

O OH HO

O COOH OH HO

O

O

COOH O OH HO

O

OH HO

O COOH OH HO

O COOH OH HO

COOH O O

O

OH HO

O COOH OH HO

COOH O O

O

COOH O O

OH HO

O

OH HO

O COOH OH HO

O COOH OH HO

Figure 8.1. Structure of alginate segments containing alginic acid.

O Poly M

O Poly G

O M-G-M-G

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The different species of brown seaweeds are harvested from the shores of many countries around the world including the British Isles, Ireland, Iceland, California, Chile, the Republic of South Africa, Namibia, Tasmania, China, and Japan. Alginic acid is composed of long, unbranched chains of two uronic acids: ␤-D-mannuronic and ␣-L-guluronic acid. These two monomers are very similar in molecular structure, with only the orientation of the carboxylic acid group on C5 differentiating them. The uronic acids are joined by 1:4 glycosidic linkages. The proportion and arrangement of the two monomers within the molecule is not fixed. It varies according to the weed species, the part of the plant, and the phase of the growing season when the weed was harvested. The ratio of the uronic acids and their arrangement within the polymer chain has an impact on the functional properties of the alginate. Table 8.2 gives the M and G contents and the M/G ratios for some of the typical weed species that are processed by various suppliers. It is therefore possible to create a spectrum of alginate properties and functionalities on the basis of the molecular structure of the polymer by blending alginates from different weeds together. The manufacturing process is controlled to produce an alginate of the required degree of polymerization (DP) and therefore of viscosity. Typically, the high G alginates are use to make strong, brittle gels while the high M-types produce gels that are more flexible and elastic. Many suppliers blend both alginate-types to produce a range of M/G ratio products for a variety of applications and to standardize the material. Table 8.2. M/G contents and ratios for alginates from different brown seaweed species. % Uronic Acid Seaweed Species

M

G

M/G Ratio

Ascophyllum nodosum Ecklonia cava Macrocystis pyrifera Laminaria digitata Laminaria hyperborea (stipes)

65 62 61 59 31

35 38 39 41 69

1.85:1 1.63:1 1.56:1 1.45:1 0.45:1

M, mannuronic acid; G, guluronic acid.

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Table 8.3. Degree of polymerization (DP) and its effect on alginate solution viscosity. Viscosity at 20◦ C (mPa.second) Alginate Type

DP

0.5%

1.0%

2.0%

Low viscosity Medium viscosity High viscosity

80 400 680

2 10 35

4 65 350

10 600 6,000

Sodium alginate is available commercially in the viscosity range 4–550 mPa.second for a 1% solution and a particle size from 63 (fine mesh) microns to 550 (coarse mesh) microns. Thus, a wide range of particle size, viscosity, and gel strength is available. Under identical conditions, the viscosity of an alginate solution is proportional to its molecular weight. As the DP increases, so does the solution viscosity. Similarly, as the solution concentration increases, the measured viscosity increases. These effects are shown in Table 8.3. A low molecular weight alginate with a DP of about 80 will produce solutions where a doubling of the alginate concentration generates a doubling of the viscosity. A medium viscosity alginate with a DP of about 400 will produce a solution with about 5 times the viscosity of the low viscosity alginate at the 0.5% level. However, this increases to 12 times at a 1% concentration and 60 times at the 2% level. A highviscosity alginate with a DP of about 680 will produce a solution with about 17 times the viscosity of the low viscosity alginate at the 0.5% level and this increases to some 600 times at the 2% level. The effect of concentration on viscosity for three typical alginates is shown in Figure 8.2. The viscosity increases rapidly with small increases in hydrocolloid concentrations. The graph shows that a typical medium viscosity alginate will show a 10-fold increase in viscosity if the concentration is doubled. The viscosity/concentration curves are not straight lines because, as the alginate concentration increases, there is more competition for the available water. In common with most other food hydrocolloids, sodium alginate solutions exhibit shear thinning or pseudoplasticity. That is, they have a lower viscosity at higher shear rates. In solution, the alginate molecule is long, thin and rigid. When the solution is at rest, the alginate molecules

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4

Viscosity (mPa.s)

High viscosity

10

3

Medium viscosity

10

2

Low viscosity 10

1

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

% Solution (as-is basis)

Figure 8.2. Alginate concentration/viscosity curves.

will interfere with each other forming loose entanglements. When shear is applied to the solution, the molecules are orientated in the direction of the shearing force. The association between the molecules is greatly reduced and there are no longer any entanglements. The result is an immediate lowering of the viscosity. When the shear is removed, the molecules entangle again resulting in recovery of the original viscosity. Low molecular weight alginates and alginates used at low concentrations show Newtonian-flow characteristics at low shear rates. As the D of P and the concentration increase, the solution becomes more pseudoplastic at all shear rates. These effects are shown in Figure 8.3.

Viscosity (mPa.s)

10 5 10 4 10 3

2.5%

1.50%

10 2 0.50%

10 1 10 0 10 0

10 1

10 2

10 3

Shear rate (per second)

Figure 8.3. Alginate solution shear rate/viscosity curves.

10 4

10 5

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Alginate Gelation The interaction between a solution of sodium alginate and free calcium ions to form a calcium alginate gel is extremely fast. It occurs in less than a second. The issue is, therefore, to be able to control the rate at which the reaction takes place so that the gel (prepared under controlled conditions), has the desired characteristics. Success lies in the choice of the alginate type and the control of the gelation reaction. In most cases, these choices can be defined by the requirements of the end product. Figure 8.4 is a pictorial representation of the “egg box model” for alginate gelation as described by Rees (1987). The hydrated alginate chains are free to move about in the solution. As calcium ions are gradually introduced into the system, they cause the alginate chains to start to align with each other. The calcium ions bind adjacent chains. As more calcium is added, the chains become progressively more bound in a three-dimensional network. In fact, it is rather like zipping up a zipper—once the zipper (the calcium ions) is in place, the additional calcium “zips” up chains together. The four major components in an alginate gelling system are: sodium alginate, a calcium salt, a calcium sequestrant, and sometimes an acid. Each of these components are considered in turn to see how they are used to help to produce a gel under ideal conditions.

+ Sodium alginate

Calcium alginate gel

Figure 8.4. Egg box model for alginate gelation.

Calcium ions

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Calcium Salts The choice of the correct calcium salt is important to the success of the system. Essentially, three types of calcium salt are used: r Those that are totally soluble in water at neutral pH, such as the

calcium chlorides.

r Those that are sparingly or partially soluble in water at neutral pH,

for example, calcium sulphate dihydrate.

r Those that are insoluble in water at neutral pH but are fully dissociated

under acid conditions, such as anhydrous dicalcium phosphate (DCP). The choice of the most appropriate calcium salt will depend upon:

r The situation in which it is being used r The percentage of calcium in the salt r Current legislation

Table 8.4 shows the percentages of available calcium from a variety of calcium salts at different pHs. A very soluble calcium salt, such as calcium chloride, is always fully ionized in solution. This means that all of the calcium in the salt is readily available to react with the alginate. The use of these very soluble salts is usually reserved for making alginate gels that are set by diffusion where little or no control on the rate of the gelling reaction is required. In contrast, calcium sulphate is a sparingly soluble calcium salt. It has very low solubility in water at neutral pH—typically approximately 0.2 g/100 mL at 20◦ C and an even lower solubility at high temperatures. However, it is totally soluble at acid pH. With salts of low solubility at a given pH, one should recall the concept of solubility product. More salt cannot dissolve until the concentration of one of the ions in the system has been reduced. In the case of calcium sulphate, the calcium ions react with the alginate; and thus more calcium sulphate can dissolve to maintain the solubility product. So the use of a sparingly soluble salt can be used to control the rate of the gelling reaction. Insoluble calcium salts are insoluble at one pH but totally soluble at another. A calcium salt such as anhydrous DCP is insoluble in neutral pH water at 20◦ C. Thus it can be dispersed and suspended in an alginate

219.08 448.39 308.30 172.17 570.51 172.09 136.14

CaCl2 ·6H2O Ca(C6 H11 07 )2 ·2H2 O Ca(C3 H5 03 )2 ·5H2 O CaSO4 ·2H2 O Ca3 (C6 H5 O7 )2 ·4H2 O CaHPO4 ·2H2 O CaHPO4 ·0H2 O

Molecular Weight

0

0.29 0.085 0.02

279 3.3 3.1

Solubility g/100 mL

1

90 30 60

100 100 100

pH 6

90

100 80 100

100 100 100

pH 4

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Totally soluble calcium salts Calcium chloride hexahydrate Calcium D-gluconate Calcium lactate Sparingly Soluble Calcium Salts Calcium sulphate dihydrate Calcium citrate Dicalcium phosphate dihydrate Insoluble calcium salt Dicalcium phosphate anhydrous

Formula

% Available Ca++

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Calcium Salts

Table 8.4. Calcium salts.

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solution at neutral pH without fear of the calcium being released and causing gelation. The addition of acid to the suspension reduces the pH, the salt ionizes and the free calcium becomes available to react with the alginate to form a gel. Again, this property of solubility caused by a change in pH is used to control the rate of the gelling reaction. Calcium Sequestrants Calcium sequestrants are used in alginate systems for two purposes: r To remove excess calcium from hard water to enable the alginate to

hydrate

r To complete with the alginate for the free calcium—thereby providing

another method of controlling the rate of the gelling reaction The activity of sequestrants is similar in some respects to some of the calcium salts in that they are also pH-dependent. Table 8.5 shows the number of parts of different sequestrants used to sequester one part of calcium. Sequestrants have optimum pH ranges for binding of calcium ions. After a sequestrant has bound (sequestered) calcium at a given pH value, if the pH is subsequently adjusted to a value where binding does not occur, or occurs less efficiently, formerly bound calcium ions will be released. Tetrasodium pyrophosphate (TSPP), for example, binds calcium well at pH 7 and higher, but does not bind well below a pH of 7. Therefore, if a neutral system containing calcium is treated with TSPP, calcium Table 8.5. Sequestrants. pH Sequestrant

Formula

Molecular Weight

Sodium hexametaphosphate (sodium polymetaphosphate, Graham’s salt, “Calgon”) Tetrasodium pyrophosphate (“Tetron”) Disodium phosphate (DSP) Trisodium citrate

(NaPO3 )n

(102.04)n

Na4 P2 O7 Na2 HPO4 C6 H5 Na3 O7

4.0

6.0

5

7

265.94

10

20

141.98 258.07

130 20

180 40

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will be bound (sequestered). If the pH is lowered below 7, subsequent to calcium being bound, calcium ions will be released back into the system and will be available for reaction with other ingredients, such as alginates. Sodium hexametaphosphate does not seem to function as a “reversible sequestrant.” Evidently it is effective at binding calcium over a wide pH range, including very low values. Sodium citrate has been found to work very well as a “reversible sequestrant,” starting to release calcium somewhere around pH 5. TSPP and trisodium phosphate may also be used for systems closer to neutrality, since they start to release calcium below pH 7. Algin gels of various types may be produced via this system, depending on conditions and the kind of acid used to adjust final pH. From Table 8.5 one can see that the different sequestrants have dif
R ferent sequestering abilities. Sodium polymetaphosphate (Calgon ) is the most effective sequestrant and is almost equally effective at pH 4.0 and 6.0. TSPP is twice as effective as a calcium sequestrant at pH 6.0 than at 4.0. Disodium phosphate is a useful sequestrant but is not as effective
R as either Calgon or TSPP. Again, it is more effective at pH 6.0 than at 4.0. Lastly, trisodium citrate is more effective at high pH than at low pH. It will also act as a buffer in the system. From these data it is possible to choose the most appropriate sequestrant and to calculate the amount of that sequestrant needed. Acids The last of the major components is sometimes an acid. In acid (low pH) systems, the choice of the type of acid can affect the rate of the reaction as well as have an impact on the acidity, pH, gel strength, and flavor of the finished product. Different acidulants possess different properties, which can be used to good effect by the product developer. Data regarding three food grade acids is shown in Table 8.6. For example, citric acid can be made up as a 50% solution having a pH of 2.4, a very acidic taste; and, in an alginate gelling system, it will tend to produce gels of slightly reduced gel strength.

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Table 8.6. Acids.

Acid Citric Glucono-deltalactone Adipic

% Solution at 20◦ C

pH 0.5%

Flavor

Effect on Gel Strength

50 50

2.4 3.5–2.9

Sharp Sweet

Slightly lower Slightly higher

1.5

3.0

Slightly mineral

Slightly lower

Glucono-delta-lactone (GDL) can also be made up as a 50% solution. It is totally soluble but the rate of hydrolysis is temperature dependent. Thus, the rate of hydrolysis (i.e., decrease in pH) can be used as a control mechanism of the gelation reaction by controlling the temperature of the system. GDL is a good acidulant, has a sweetish taste, and gives gels with high-gel strengths. A slowly dissolving acid such as adipic acid is another useful acidulant. The rate at which it dissolves can be used to control the rate of the gelling reaction. It gives a solution with a slightly mineral taste and produces gels of slightly lower gel strength. Alginate Gelation Typically, one of three general processes is used for restructuring food materials using alginates—diffusion setting, internal setting, and combination setting. All of these processes can be done at both neutral and acid pH. These processes will be described here briefly and in more detail later in the paper. Diffusion Setting The diffusion setting method can be used to make both neutral and acid materials. In a neutral pH system, an alginate, sequestrant, and the comminuted food material to be restructured are mixed together. Calcium ions from a readily soluble calcium salt such as a calcium chloride or calcium lactate diffuse into the alginate solution containing the disassembled food material to be gelled or restructured and bind with the alginate and form the gel. The gelling reaction is very fast in the absence of a sequestrant which can be included to slow down the

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Ca++ Ca++ Ca++

Ca++ Ca++

Ca++ and sodium alginate

Ca++

Ca++ Ca

++

Calcium chloride or calcium lactate

Figure 8.5. Diffusion setting—neutral conditions.

rate of the gelation to enable a good, coherent gel to be formed (see Figure 8.5). Restructured fish can be made on a small scale by diffusion setting. A formulation is given in Table 8.7. The alginate is dissolved in water and the minced fish is added to the alginate solution. The resulting paste is formed into the required shape by depositing it in moulds and the initial setting is brought about by spraying the exposed surface of the paste with a calcium chloride solution. When the skin is strong enough, the setting piece is put into a calcium lactate setting bath. In the acid pH system, the alginate, a sequestrant such as sodium hexametaphosphate, and calcium salt are mixed together. The choice of calcium salt is important—in this system DCP anhydrous is chosen because it is essentially insoluble at neutral pH but almost totally soluble at acid pH. A food quality acid is allowed to diffuse into the alginate mix, the pH is reduced, and the calcium ions are released from the calcium salt. The hydrogen ions react with the alginate to form a calcium alginate Table 8.7. Where to put the calcium salt? Internal Setting Systems Product pH

Calcium Salt

Phase

Neutral Acidic

Calcium sulfate dihydrate Dicalcium phosphate anhydrous

Puree Alginate

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H+ H+

Sodium alginate + DCP + sequestrant H+

H+ +

H Acid

Figure 8.6. Diffusion setting—acid conditions.

gel. It should be noted that the reaction of the calcium ions to the alginate is instantaneous; thus, to allow time for the gel network to be formed optimally, a calcium sequestrant is usually included in the formulation. It slows down the rate of the gelling reaction and allows the gel to form properly (see Figure 8.6). These simple systems can be used to restructure a number of food products such as small fruit-like pieces for inclusion into cakes and muffins, fish eggs such as artificial caviar and pimiento strips for stuffing into cocktail olives, and even for making a continuous olive pipe which is subsequently sliced and use to decorate pizzas and onion rings. Internal Setting With the internal setting process, two phases are used to keep the reacting species separate until the reaction is to be started. The ions that cause the alginate to gel are generated inside the alginate solution, and the reaction is initiated by a “trigger” that causes the release of calcium ions from the calcium salt. The choice of trigger is determined by the type of calcium salt chosen (see Table 8.4). Typically, a trigger can be one of the following: – A change in temperature – An excess of water – An acid In neutral pH systems, calcium sulphate dihydrate is the calcium salt. This salt is of limited solubility, and it relies on excess water to dissolve it. Thus, it is put into the neutral puree phase. When the two phases

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Puree phase + CaSO4.2H 2O

Alginate phase

Mix

Calcium alginate gel

Figure 8.7. Internal setting—neutral conditions.

(puree and alginate) are mixed, more water is immediately available for the salt to dissolve in, and the released calcium is bound by the alginate to form the gel. This reduces the amount of free calcium in the system thus more sulphate is able to dissolve. When the gel is to be formed, the two phases are mixed together. The total mixture is then deposited and allowed to set under shear-free conditions (Figure 8.7). The trigger, in this case the excess water in the alginate phase, causes more calcium sulphate to dissolve. This allows more of the calcium salt to ionize into the system to react with the alginate to form the gel. Gradually, as the free calcium ions are bound by the alginate, more calcium salt ionizes and is bound until eventually all of the calcium salt is used up. In many situations the rate of calcium release from the calcium salt is so rapid that a sequestrant is included to control the setting rate. The sequestrant competes with the alginate for calcium ions. Sequestrant such as sodium hexametaphosphate, TSPP, and trisodium citrate are frequently used. However, while the sequestrant causes the gel to take longer to set, it also results in a weaker gel because some of the calcium ions are bound by the sequestrant rather than by the alginate. Thus, it is necessary to establish the correct balance between the concentrations of the alginate, the calcium salt, and the sequestrant to get optimal performance from the system. Control of the gelling rate with sequestrants is only necessary during the mixing and depositing operations to prevent premature gelation and irreversible breakdown of the gel structure, since once a gel starts to

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form it will not reset if it is broken. When fast, efficient mixing equipment is used, only a relatively small amount of sequestrant is needed since only a small proportion of the calcium salt has the opportunity to dissolve during the mixing process. In such situations very fast setting, strong gels can be made. In an acidic internal setting system, an insoluble calcium salt such as DCP anhydrous and the alginate are put into the same phase. Since the calcium salt is insoluble at the pH of the alginate solution, no calcium ions are available to react with the alginate. A second phase containing an acid (the trigger) and the puree is then intimately mixed with the alginate phase. The acid lowers the pH of the whole mixture thereby allowing the calcium salt to dissolve and ionize. The calcium ions react with the alginate and form a gel. The whole mixture is then deposited and allowed to set in shear-free conditions (see Figure 8.8). Table 8.7 summarizes the calcium salts typically used in the internal setting systems and the phases in which they are put. Combination Setting Combination Setting, as the phrase implies, is a combination of the diffusion and internal setting systems. The idea is that both mechanisms are invoked simultaneously. This process reduces the overall setting time and also allows the setting pieces to be moved to another processing station while the internal setting mechanism is still in operation.

Alginate phase + sequestrant + DCP

Puree phase (low pH)

Mix

Calcium alginate gel

Figure 8.8. Internal setting—acid conditions.

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185

Puree Phase + CaSO4.2H 2O

Mix Ca++ Ca++

Ca++ Ca++

Calcium alginate gel

Ca++

Ca++

Ca++ Ca++ Calcium chloride or calcium lactate

Figure 8.9. Combination settings—neutral conditions.

In a neutral pH combination setting system, the alginate phase containing a sequestrant is mixed with a separate phase, which contains a sparingly soluble calcium salt such as calcium sulphate dihydrate. The phases are mixed in the appropriate ratio and deposited as drops or pieces in a solution containing a solution of a freely soluble calcium salt (see Figure 8.9). The pieces entering the bath are immediately coated with a calcium alginate film or skin. This film increases in thickness and strength while the piece is in the bath. Separately, the internal setting system is operating. The excess water in the alginate phase causes more calcium sulphate to dissolve and ionize. The calcium ions react with the alginate inside the piece to form the gel. Once the skin around the piece is strong enough, the pieces are harvested and further processing can be continued as necessary. During this time, the internal setting process proceeds to completion. Combination setting at acid pH again uses two phases and a calcium setting bath. The alginate phase contains the alginate, a sequestrant to modify the rate of the gelling reaction, and a calcium salt that is insoluble at the pH of the phase such as DCP anhydrous. The acid puree phase usually contains an added acid as well as the pureed acidic foodstuff to be restructured. The two phases are mixed, the low pH

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Alginate phase + sequesterant + DCP

Puree phase

Mix H+ +

H+

H H+

Calcium alginate gel H+

H+

H+ H+ Acid

Figure 8.10. Combination settings—acid conditions.

causes the calcium salt to dissolve and ionize, and the calcium ions partition between the alginate and the sequestrant and start to form the alginate gel. Pieces of the setting mix are deposited into the calcium setting bath (Figure 8.10). The calcium ions in the bath immediately react with the alginate in the mix and form a skin around the pieces. Once the piece is strong enough, it is harvested and passed on for the remainder of the processing operation. During this time the internal setting mechanism moves to completion.

Examples of Restructured Foodstuffs Diffusion Set Products Restructured Pimiento Strip Restructured pimiento strip for stuffing into pitted olives is a classic case of problem solving using diffusion setting alginate chemistry. The original driver for this in the 1960s was to move from a highly intensive manual operation to a continuous production system. In the automated

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process a long, wide strip of restructured whole pimiento is produced in a setting bath containing calcium chloride. The strip was designed to be strong enough the be cut easily without tearing. It had to be strong enough to be handled mechanically. It had to be flexible so that it could be bent like a hairpin to be forced into the pit hole in the olive. It had to withstand a pasteurization process. It also had to have minimum syneresis and shrinkage so that it would not fall out of the hole in the olive. The gelled sheet is cut lengthwise as it leaves the setting bath and stored in an acidic calcium ion solution until required for stuffing. Once stuffed, the olives are bottled or canned and pasteurized to provide the required shelf life. A formulation for restructured pimiento strip is given in Table 8.8. Whole pureed red pimiento is mixed with water and potassium sorbate (preservative), sodium alginate, and guar gum. The mass is intimately mixed for several minutes to ensure that there are no lumps, that the mixture is homogeneous, and that the gums have hydrated. Table 8.8. Restructured pimiento strip formulation. Phase

Ingredients

%

Alginate

Sodium alginate Guar gum Potassium sorbate Pimiento concentrate (or whole red peppers to give the same concentration of solids) Deionized water Total (%)

83.50 100.00

Setting bath

Calcium chloride anhydrous Potassium sorbate Water Total (%)

8.00 0.10 91.90 100.00

Aging bath

Sodium chloride Calcium chloride anhydrous Lactic acid Potassium sorbate Water Total (%)

8.00 2.00 1.20 0.10 88.70 100.00

1.60 0.80 0.10 14.00

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The setting bath (approximately 1 yard wide and 60 yards long) contains a solution of calcium chloride and a preservative. The viscous pimiento paste is extruded under gravity into the bath as a wide continuous sheet about one-fourth of an inch thick. The setting sheet moves along the bath propelled by more paste being extruded. The density of the bath solution causes the sheet to float. At the end of the bath the sheet is cut lengthwise and the smaller sheets are fed into drums containing storage solution. The storage solution, comprising sodium, and potassium chloride lactic acid and water preserves the strip but also allows ion exchange to occur between the strip and the solution to ensure that the strip is evenly gelled. Essentially this is a rearrangement of the gel network. When it is to be used for stuffing olives, the strip is fed into a machine that automatically pits the olive, slices off a predetermined width of strip, doubles it over, and pushes it into the pit. The stuffed olives are packed into glass jars or metal cans, pasteurized, and stored. A second, more recent innovation is to restructure the olive itself as a continuous tube—rather like a piece of garden hosepipe. Again, this is made by a diffusion process with the calcium ions in the bath gelling the outside of the tube and a calcium ion solution being forced through the center to form the central hole and to start the gelling process for the inside. Once set, the tubes are kept preserved until required and then sliced into rings. These rings can be used on pizzas and other ready-toeat products. The advantage of this approach is that all of the pitted olive can be restructured. There is no waste, and all of the rings are of the same size, weight, and shape. The apparatus for making the tube is quite simple, and the internal and external diameters of the ring are constant.

Restructured Onion Rings Restructured onion rings are a well-established example of an alginate diffusion setting process that was designed for a specific application. It provides a method of exact portion control thereby filling a market niche. Onion rings can be made with fresh onions or rehydrated dry onion pieces (see Table 8.9). In both cases the pieces are chopped to a given size and intimately mixed in a ribbon blender with water, flour, salt and a fine mesh alginate. A small particle size alginate is used to ensure fast hydration.

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Table 8.9. Restructured onion ring formulation. Phase

Ingredients

%

Alginate/onion

Minced, dehydrated onions Flour Salt Sodium alginate Water Total (%)

20.00 14.00 0.10 1.10 64.80 100.00

Setting bath

Water Calcium chloride hexahydrate Total (%)

95–97 3–5 100.00

The viscous mass is pumped into a hopper, which delivers aliquots of it down the outside of a hollow tube into a circular recess in the forming plate. A calcium chloride solution in the recess caused immediate formation of a calcium alginate skin around the outside of the ring. The ring remains in the calcium solution for less than 1 second by which time it is strong enough to be ejected automatically and passed along the line for further processing. The very short residence time in the calcium solution is sufficient to form a coherent calcium alginate skin around the annulus. This gives the piece enough strength to be ejected and moved and manipulated during the rest of the production process. The short residence time also ensures that the ring does not gel all the way through. The ring passes to the breading and/or battering station, followed by a frying stage before being packed and stored in a deep freeze. One of the early claims for this technology was that the alginate skin formed a barrier to oxygen thereby preventing the natural onion oils from oxidizing. In principle, other ring-type products could also be made by this technology (e.g., rings of mushroom or tomato). Restructured Fish Restructured fish can be made on a small scale by diffusion setting. A formulation is given in Table 8.10. The alginate is dissolved in water, and the minced fish is added to the alginate solution. The resulting paste is formed into the required shape by depositing it in moulds, and the

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Table 8.10. Restructured fish formulation. Phase

Ingredients

Alginate/fish

Thawed, minced fish Sodium alginate (high M, small particle size) Water Total (%)

48.25 100.00

Calcium lactate anhydrous Lactic acid Sodium chloride Water Total (%)

1.00 1.00 8.00 90.00 100.00

Setting bath

% 50.00 1.75

M, mannuronic acid.

initial setting is brought about by spraying the exposed surface of the paste with a calcium chloride solution. When the skin is strong enough, the setting piece is put into a calcium lactate setting bath. A variety of shapes can be made using this simple technology. For example, reformed fillets of sole can be made using a mould shaped like a sole fillet with ridges in it to simulate the muscle blocks. Fun fish shapes or other shapes that would interest children could be other options as these could prepare shapes for the catering industry where size, shape, and portion control are important. It should be noted that this approach is only suitable for low volume products and for laboratory development work. The limiting factor is time. Since the calcium reacts with the alginate so quickly, there will not be enough time to add the two parts together, mix, and pour out before the gelling reaction starts. On a larger scale, one would try to use the internal or combination setting techniques. Solid and Liquid-Centered Berries Figure 8.11 shows a specially designed apparatus for making solid and liquid-centered berry fruits such as raisins and sultanas, black currants, and blueberries. Solid materials can be made with real fruit or fruit concentrates as well as artificial fruit-like materials for cakes and pastries. Here a solution of sodium alginate, sugar (if necessary), colors, and flavors is pulsed down the central tube. As each drop of material leaves the tube, it falls into a setting bath comprising a soluble calcium salt,

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Coaxial tubes Fruit preparation Alginate solution

Harvest

Calcium setting bath

Figure 8.11. Apparatus for solid and liquid-centered berries.

such as calcium lactate or chloride. Surface tension causes the drop to become spherical. A skin of calcium alginate immediately forms around the drop. As the piece passes along the setting bath, more calcium ions diffuse into it and it becomes progressively harder. Finally, the pieces are harvested and processed further as required. A similar device with a mechanical cutter can be used to make larger fruit pieces such as cherries. Typically this would use an acidic setting bath and the density would be adjusted with sugar to enable the setting spheres to float. For a liquid-centered fruit like black currant, a sodium alginate solution and a fruit phase are prepared separately. The latter contains pureed fruit, an acid, a soluble calcium salt, thickening agents, and water (see Table 8.11). A central core of the liquid fruit preparation is pulsed down the central tube. At the same time, a continuous film of the alginate solution is pumped down the outside of this tube at a given rate. As each pulse of puree breaks away from the nozzle, it is coated in a thin, uniform coat of the alginate solution. When the berry drops into the calcium-setting bath, a film of calcium alginate is immediately formed around the liquid center. As the berry passes along the bath, more calcium ions diffuse into it to make the skin firmer. The berries are harvested and transported for further processing. In addition, artificial caviar and fish eggs can also be made just by using the central tube. Summary of diffusion setting As with most things in life, there are both advantages and disadvantages to any given system. Diffusion setting is no different, some of these are shown on the next page.

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Table 8.11. Restructured black currant formulation. Phase

Ingredients

%

Alginate

Sodium alginate Water Total (%)

2.00 98.00 100.00

Fruit

Black currant puree Citric acid anhydrous Calcium lactate pentahydrate Sucrose Cross-linked potato starch Xanthan gum Water Total (%)

41.00 0.20 1.00 12.70 1.70 0.50 42.80 100.00

Setting bath

Calcium lactate pentahydrate Water Total (%)

3.00 97.00 100.00

Advantages r It is a very simple process. r A single alginate phase is prepared and introduced into the setting

bath

r The shape of the gelled piece will be determined by the rheologi-

cal properties of the alginate solution phase and the way that it is deposited into the setting bath. Disadvantages r A diffusion set gel is not an ideal approach where time is an issue or

where a bottleneck in the production process causes a problem.

r It takes a finite time for ions to diffuse from the outside to the center

of the material to be set. As a rule of thumb, it takes about 1 hour to gel a preparation thickness of 1 cm. Internal Set Products—Neutral pH In a neutral pH internal setting system, calcium sulphate is used as the source of calcium ions. The alginate phase contains the alginate and

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sequestrant and the puree phase a neutral pH puree, such as pureed vegetable, calcium sulphate, and a starch. The calcium sulphate is kept separated from the alginate because it is soluble enough to cause premature gelation. The two phases are pumped in the appropriate ratio into a high-speed mixer where they are intimately mixed and deposited onto a moving conveyor belt as a slab and allowed to set. The control of the gelling reaction depends not only on the level of calcium salt but also on the amount of dissolved calcium in the puree phase before the two phases are mixed. It is essential to ensure that the water content of the puree phase is kept to a minimum to keep the amount of free calcium ions to a minimum. Neutral pH food materials such as eggs, meat, fish, and some vegetables can all be restructured with alginates to good effect using the internal setting process. A few examples of such products are given below. Restructured Egg Products The following data on restructured egg products is proprietary to International Specialty Products or ISP (reproduced with permission). A formulation is given in Table 8.12. This restructured egg product is ideally suited to food service operations. Unlike products in which the protein is cooked twice, this system heats the protein only once. This, then, offers the following features: r Versatility: the product is suitable for fast food service, institutional

catering, or frozen retail sale.

r Simplicity: there is no complicated preparation work and the product

can be made manually of by an automated process. Table 8.12. Restructured egg formulation. Ingredients

%

Pasteurized whole egg Manucol JKT alginate blend Calcium sulphate dehydrate Water or nonfat milk Total (%)

67.35–97.35 1.65 1.00 30.00–0.00 100.00

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r Ease of preparation: it is made cold and then frozen; no intermediate

cooking is needed.

r Longer shelf life: the product is freeze-thaw stable and is stable for at

least 18 weeks at deep freeze temperature.

r Texture and convenience: the product is cooked at the point of service.

This gives a product with a superior texture to a precooked egg product. It can be cooked by deep or shallow fat frying, by baking, in a convection oven, or on a griddle. r Color retention: the natural egg color is retained during frozen storage. r Taste and texture: the product retains its texture well. Flavoring agents, herbs, and spices can also be added to it during the production process. Preparation 1. Dissolve the Manucol JKT alginate blend in the egg or into the egg and water (or nonfat milk) mixture using a high-speed stirrer. Mix for 2–3 minutes until the alginate blend is completely dissolved. 2. Slurry the calcium sulphate dihydrate in a little water and mix it in thoroughly with the alginate/egg mix with a high-speed stirrer. 3. Pour the liquid into moulds and allow it to set for 5–10 minutes; then freeze. Once frozen, the egg burgers can be removed from the moulds. The product should be cooked directly from frozen; no defrosting is needed. Restructured Chicken Pieces The formulation shown in Table 8.13 uses 80% meat, and the final product is stable to freeze-thaw, retorting, boil-in-the-bag, or deep fat frying. Preparation 1. Mix the shredded chicken and water together. 2. Sprinkle on the sodium alginate and TSPP, and mix for 10 minutes. 3. Slurry the calcium sulphate dihydrate and the water and add it to the mixer. 4. Continue mixing for 1–2 minutes. 5. Pour the mix into moulds.

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Table 8.13. Restructured chicken pieces formulation. Phase

Ingredients

%

Alginate

Shredded chicken flesh (raw) Water Sodium alginate (high M, medium viscosity) Tetrasodium pyrophosphate Total (%)

80.00 11.81 1.54 0.11 93.46

Calcium

Water Calcium sulphate dihydrate Total (%)

5.00 1.54 6.54

M, mannuronic acid.

6. Allow the mix to set to a firm gel. 7. Cut into the required shapes and further package and/or process as required. Restructured Salmon This formulation (Table 8.14) allows the production of a restructured smoked salmon block from fish trimmings. The product can be sliced to give the consistent portion control required for catering operations. Table 8.14. Restructured salmon formulation. Phase

Ingredients

Alginate

Water Maltodextrin Pregelatinized waxy maize starch Sodium alginate (High G, medium viscosity) Xanthan gum Tetrasodium pyrophosphate Total (%)

19.35 5.00 1.00 0.50 0.10 0.05 26.00

Fish #1

Smoked salmon mince Water Calcium sulphate dihydrate Total (%)

7.00 3.50 0.50 11.00

Fish #2

Smoked salmon pieces Total (%)

G, guluronic acid.

%

63.00 100.00

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Preparation 1. Blend together the dry materials in the alginate phase. 2. Dissolve the dry mix into the water using an high speed or high shear mixer. 3. Mix the calcium sulphate, water, and salmon mince together. 4. Mix together the alginate phase and the Fish #1 phase. 5. Quickly pour this mixture over the salmon pieces and mix gently (taking care not to break the salmon pieces). 6. Transfer the mixture to a tray and leave it to set under shear-free conditions at 5◦ C for about 2 hours. 7. Freeze and slice as required. Restructured Neutral pH Vegetables This formulation (Table 8.15; Process Diagram Figure 8.12) is for restructured carrots; but it can be applied equally well to other neutral pH vegetables such as mushrooms. The products can be used as they are or dehydrated for use in instant soups and meals. At first glance it may appear that restructuring a cheap raw material such as carrots is not a viable proposition. However, if the product is to be processed further (e.g., dehydrated) and must perform optimally in a specific situation (e.g., rehydrated in an instant soup to give the required texture), then restructuring could be not only a good option but the best one even when the cost of the restructuring process is taken into account. Table 8.15. Restructured carrot formulation (neutral pH). Phase

Ingredients

%

Alginate/Vegetable

Cooked carrot puree Water Sodium alginate (high G, high viscosity) Waxy maize cook-up starch Pregelatinized potato starch Total (%)

50.00 42.20 1.00 1.00 0.50 94.70

Calcium

Water Calcium sulphate dihydrate Total (%)

G, guluronic acid.

5.00 0.30 5.30

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197

Puree phase

Mixer Pump

Pump

Reciprocating cutter Harvest

Conveyor belt

Figure 8.12. System for internal set fruit and vegetables—neutral pH.

Note: when mushrooms are to be reformed, it is advisable either to cook and puree them before further processing or to treat them with a macerating enzyme to help break down the cell walls so that they can be pureed easily. Preparation 1. Prepare a mixture of the carrots and water. 2. Dry blend the sodium alginate and the starches. 3. Add the dry blend to the carrot/water mixture with vigorous agitation until a homogeneous paste is formed. 4. Disperse the calcium sulphate dihydrate in the water and add this slurry to the alginate/puree mixture. 5. Mix for 1 minute and deposit into moulds. Allow to set under shearfree conditions. 6. Once set, the gel can be cut or diced and dried in a fluid bed drier at approximately 60◦ C. When a conveyor belt system is used, the mix is extruded onto the belt and allowed to set under shear-free conditions. At the end of the belt, the set gel can be cut using a scrapless cutter. Restructured Meat Products None of the products described in this section on restructured meat products require specialized processing equipment.

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Table 8.16. Restructured brawn formulation. Phase

Ingredients

%

Alginate

Water Sodium alginate (high G, high viscosity) Potassium sorbate Sodium metabisulphite Sodium hexametaphosphate Total (%)

52.32 1.00 0.15 0.08 0.05 53.60

Meat

Cooked minced meat Total (%)

40.00 40.00

Calcium

Water Glucono-delta-lactone Dicalcium phosphate dihydrate Total (%)

5.00 1.10 0.30 6.40

G, guluronic acid.

Pet food brawn Table 8.16 shows an old formulation for pet food brawn that was used for many years in the United Kingdom. While it is no longer used, it could be easily adapted for use by small catering establishments. A homogeneous meat gel suitable for pet food can be made using this formulation. The gel does not melt or soften, even when stored under warm conditions (but this is not recommended) and, with good hygienic manufacturing practices, it has a good shelf life at ambient temperatures. Preparation 1. Mix the dry ingredients in the alginate phase together. 2. Dissolve this mix into the water using a high-speed or high-shear mixer. 3. Add this solution to the minced meat and blend in thoroughly. 4. Add the GDL to the water and mix for 30 seconds to allow the GDL to dissolve completely. 5. Add the DCP dihydrate to the GDL solution to form a slurry. 6. Immediately mix the slurry into the alginate/meat preparation, mix thoroughly and quickly, and deposit into containers. 7. Allow the gel to set under shear-free conditions.

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Table 8.17. Restructured meat burger formulation. Phase

Ingredients

%

Alginate/meat

Meat Sodium alginate (high G, medium viscosity) Water Total (%)

50.00 1.00 43.00 94.00

Calcium

Calcium sulphate dihydrate Water Total (%)

1.00 5.00 6.00

G, guluronic acid.

Prepare the calcium phase at the last minute. It must not be prepared and stored for later use because the GDL will hydrolyze, reduce the pH, and allow the DCP to dissolve. This would cause the system to gel too quickly under uncontrolled conditions, which would result in a broken gel which would never reform properly. Burger-Type Products This (Table 8.17) shows a simple example of a restructured meat product made by internal setting. Burger-type products as well as fun shapes for children can be made with meat comminuted (in a bowl chopper) or minced and stuck together with an alginate gel using calcium sulphate dihydrate as the calcium source. Such products can be used fresh or frozen and thawed before cooking and can also be dehydrated for use in instant soups and meals. It is important to note that only meat with <20% visual fat should be used for all restructured meat formulation. Fat will not be bound easily by alginate gels, hence a large proportion of fat in the recipe will prevent a homogeneous gel from being formed. A formulation is given in Table 8.17. It should be noted that for quantities of more than approximately 0.5 kg a calcium sequestrant such as TSPP may be needed to slow down the gelling reaction rate to enable the two phases to be mixed together intimately before being deposited into a container. Preparation 1. Disperse and dissolve the sodium alginate in the water using a highspeed or high-shear mixer. 2. Comminuted (bowl chopper) or mince the meat.

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Table 8.18. Internal set beef formulation. % Ingredients

A

B

Minced beef Water Sodium alginate (high G, medium viscosity) Tetrasodium pyrophosphate Calcium sulphate dehydrate Total (%)

93.37 4.68 0.93 0.09 0.93 100.00

78.35 19.59 0.98 0.10 0.98 100.00

G, guluronic acid.

3. Mix the alginate solution intimately with the comminuted meat. 4. Disperse the calcium sulphate dehydrate with the water of the calcium phase to make a slurry. 5. Add the calcium slurry to the alginate/meat preparation and mix quickly. 6. Deposit into containers or moulds. 7. Allow to set under shear-free conditions. Internal Set Beef This formulation (Table 8.18) for a simple restructured meat product can be made easily. Once set, it can be cooked by roasting, frying, grilling, or as a component in a boil-in-the-bag preparation. Preparation 1. Disperse the alginate and sequestrant directly into the minced meat with good agitation. 2. Slurry the calcium sulphate dihydrate in about 5 times its weight of water and mix it into the meat/alginate preparation for 2 minutes (A). For B, do the same but stir the difference of the water into the meat preparation before adding the calcium salt slurry. 3. Put the mix into a mould and allow it to set for about 2 hours. 4. The gelled product can be frozen if required. Restructured Meat A modification of the above is the use of encapsulated calcium lactate as the source of calcium ions. Coarse and fine ground meats are mixed in the ratio of 80:20. Sodium alginate,

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Table 8.19. Restructured meat formulation. Ingredients Coarse ground beef, 80% lean, ground through a 3/4 × 2 1/2 kidney plate Fine ground beef, 70–90% lean, ground through a 3/16–1/4 plate Sodium alginate (high G, high viscosity)/calcium carbonate mixture Encapsulated lactic acid/calcium lactate Total (%)

% 79.2 19.8 0.5 0.5 100.0

G, guluronic acid.

sometimes with additional water, is mixed in for about 10 minutes (see Table 8.19). Finally, the encapsulated calcium salt is carefully blended into the meat/alginate mass for 1–3 minutes. The mass is deposited into moulds or stuffed into sausage casings and left at refrigerator temperature overnight to allow the alginate to form a gel before further processing. The mixture of two sizes of meat pieces provides additional texture and “bite” to the finished product. The product can be stored chilled or frozen until required and can be cooked in the usual way. A word of caution—if the meat contains much more than 20% fat, the bind will not be very good because the alginate will gel water but not fat. Potato Products The increasing demand for convenience foods and for new and more varied ways of presenting potatoes provides important opportunities for innovative companies. The sales of french fries continue to increase as do the needs for other innovations such as oven-ready products and ethnic dishes (e.g., Pommes noisettes). Based on this, it is likely that other potato texture and flavor variations could further stimulate a growing market. In addition, with the current emphasis on providing children (and adults) with lower fat foods to reduce or even prevent obesity, this approach could be a good option to consider. The internal setting mechanism at neutral pH can be used to produce novel potato products. Product texture variations can be achieved by altering the quantities and ratios of the alginate and calcium salt and the

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Hydrocolloids in Food Processing Potato flake

Water

Mix Alginate, seasoning, calcium salt, phosphate

Mince

Potato pieces

Potato starch

Shredded Potato

Mix

Hydrate extrude, pipe, mould Hydrate

Figure 8.13. Restructured potato products from different ingredients.

reaction is controlled with a phosphate-based calcium sequestrant. The type of alginate (high G or high M) and the amounts of calcium salt and sequestrant used will also depend upon the potato raw material. Figure 8.13 shows the various techniques used with different potato starting materials. Maximum efficiency from the alginate is usually obtained by predissolving it in water and then adding the seasoning, calcium salt, phosphate, and potato flake or mash. However, if a small particle size alginate is used, one can reduce the production time (to fit in with a current manufacturing process) by dry blending it with the calcium salt, seasonings, and phosphate and using this mixture as a single shot dose. A process for making potato products using potato flake or powder is as follows:

Preparation (Table 8.20) 1. Disperse and mix the alginate in the water using a high-speed or high-shear mixer for 10–15 minutes. 2. Blend together the remaining dry ingredients. 3. Add the alginate solution to the powders and mix further for 1–2 minutes. 4. Leave the mixture to hydrate completely for 4–5 minutes. 5. Roll out, extrude, or form into the required shapes. 6. If a filling is to be added (e.g., for a potato turnover), insert the filling and crimp the edges. 7. Freeze. 8. Cook from frozen by deep-fat frying at 160◦ C for 10 minutes.

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Table 8.20. Restructured potato formulations.

Phase

Ingredients

Alginate

Sodium alginate (high M, high viscosity, small particle size) Sodium alginate (high G, high viscosity, medium particle size) Water Total (%)

Calcium/ Potato

Potato flake Salt Calcium sulphate dehydrate Tetrasodium pyrophosphate Total (%)

Duchesse % 0.35

Croquette % 0.35

French Fries % —

—

—

0.50

78.75 79.10

75.80 76.15

73.35 73.85

20.00 0.60 0.20

23.00 0.60 0.20

25.00 0.60 0.45

0.10

0.05

0.10

20.90

23.85

26.15

M, mannuronic acid; G, guluronic acid.

Combinations of potato mash with mince and/or dice and/or shreds can also be used to generate even more textural variations. Internal Set Products—Acid pH In an acid system, an insoluble calcium salt (DCP anhydrous) and the alginates are put into the same phase. Since the calcium salt is insoluble at the pH of the alginate solution, no calcium is available to react with the alginate. A second phase containing an acid (the trigger) is intimately mixed with the alginate phase. The acid causes the calcium salt to dissolve thereby releasing calcium ions, which react with the alginate. The total mixture is then deposited and allowed to set under shear-free conditions. On a large-scale process, the two phases are prepared and kept apart. When the product is to be made, the phases are pumped together at the appropriate ratio into the high-speed mixer, deposited onto a moving conveyor belt, and allowed to set under shear-free conditions.

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Table 8.21. Acid pH model gel system. Phase

Ingredients

%

Alginate

Deionized water Sodium alginate (high G, high viscosity) Trisodium citrate Dicalcium phosphate anhydrous Total (%)

89.03 0.72 0.07 0.18 90.00

Acid

Deionized water Citric acid Total (%)

9.78 0.22 10.00

G, guluronic acid.

When the two phases come into intimate contact in the mixer, the acid in the puree phase causes the pH of the total mix to be lowered thereby releasing the calcium from the DCP. The calcium, in turn, reacts with the alginate to form the gel. The sequestrant slows down the gelling reaction long enough for the mix to be deposited before gelation starts. Table 8.21 gives a model formulation for an acid pH gel. The trisodium citrate, which acts as the calcium sequestrant, is put into the alginate phase. The citrate will sequester calcium from the water (this is especially important in hard water areas) and from the DCP in the ionized state. This model can be used to help design different restructured food formulations. Small variations made one at a time in the various ingredients will help the product developer to understand which one is determining the rate of the reaction and the subsequent gel strength. When the two phases are mixed, the pH of the whole system is lowered. The DCP releases calcium, which is then bound by the alginate. The citrate will slow down the rate of the calcium–alginate reaction to enable the most stable linkages to be formed. Preparation 1. Disperse the sodium alginate in about 90% of the water of the alginate phase using a high-speed or high-shear mixer. 2. Dry mix the trisodium citrate and DCP anhydrous together and disperse this mix in the remainder of the water of the alginate phase. 3. Mix the citrate/phosphate solution with the alginate solution. 4. Dissolve the citric acid in the water of the acid phase.

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Puree phase Mixer

Pump

Pump

Reciprocating cutter Harvest

Conveyor belt

Figure 8.14. System for internal set fruit and vegetables—acid pH.

5. Add the acid solution to the alginate preparation and mix thoroughly for a few seconds. 6. Pour the setting mixture into a mould and allow it to set under shearfree conditions. Acidic pH food materials such as fruit and vegetables can also be restructured with alginates using the internal setting process. A few examples of such products are given below. A typical arrangement of the necessary machinery is shown in Figure 8.14. Internal set peach formulation This formulation (Table 8.22) can be used to produce standardized structured fruit suitable for use in a range of desserts and fillings. Different shapes may be made by gelling the mixture in moulds to give fast-baking, freeze-thaw stable products. Fruit pieces, which have a natural texture at deep freeze temperatures, may be made for use in ice cream or frozen desserts due to the increase in soluble solids. As with the neutral version, the mix can be deposited onto a conveyor belt and cut into pieces once set, or it can be deposited into specially shaped moulds fitted to the belt and ejected at the end of the conveyor. Preparation 1. Blend together the alginate, dry material of the alginate phase. 2. Disperse this mix in the water using a high-speed or high-shear mixer. 3. Blend together the dry material of the fruit phase.

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Table 8.22. Internal set peach formulation. Phase

Ingredients

%

Alginate

Sodium alginate (high G, high viscosity) Dicalcium phosphate anhydrous Sodium phosphate dibasic, Na2 HPO4 ·12 H2 O Glucose Sucrose Water Total (%)

0.85 0.30 0.07 5.00 5.00 38.78 50.00

Fruit

Fruit puree Sucrose Glucose Citric acid anhydrous Sodium citrate dehydrate Total (%)

33.55 10.00 5.00 0.80 0.65 50.00

G, guluronic acid.

4. Disperse them into the fruit puree using a high-speed mixer. 5. Mix the two phases together rapidly and deposit the mixture into a mould or moulds and allow the gel to set under shear-free conditions. The above formulation can be used for a variety of fruits including peach, pear, pineapple, and mango. The pH of the fruit gel should be 3.0–4.2. Additional sodium citrate or citric acid should be used to adjust the pH if it lies outside this range. Combination Setting With combination setting, both the diffusion and internal setting systems are used together. Typically, a two-phase system is set up and extruded into a calcium bath. The action of the calcium in the bath causes immediate skin formation. The thickness of the skin increases during the residence time in the bath. At the same time, the internal setting mechanism is operating. A combination setting system therefore reduces the setting time of a diffusion setting system. Again, this approach can be used for both neutral and acidic foodstuffs. Combination Setting—Neutral pH Restructured Pet Food Chunks Formulation Using alginate to restructure canned pet food is an old and well-established technology (see

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Calcium salt phase

Alginate + meat phase Pump Pump Cutter

Harvest

Mixer

Setting bath

Figure 8.15. System for combination set pet food chunks.

Figure 8.15). In recent years it has been largely superseded in some countries by alternative systems using heat setting technology. However, it does demonstrate how evenly shaped pieces of a natural raw material can be made using the combination setting system. A twophase system is used. The alginate phase comprises sodium alginate minced meats and a sequestrant dispersed in water. Often the alginate is made up as a presolution in sequestered water. This solution is then intimately mixed with the minced meats. Separately, a calcium phase is prepared. This comprises calcium sulphate dihydrate suspended in an aqueous guar gum or starch solution. The guar gum not only suspends the calcium salt homogeneously to ensure even gel formation, but it also helps to reduce the overall syneresis by absorbing some of the liquid exuded form the meats during the sterilization treatment. Since calcium sulphate dihydrate is a sparingly soluble calcium salt, only about 0.2% is ionized. This gives enough time for a small mix to be prepared extruded, cut, and sent to the setting bath. A setting bath containing a calcium chloride solution is also prepared. System for combination set pet food chunks: In a continuous production situation the meat/alginate phase is pumped to a continuous high-speed mixer. The calcium/guar gum phase is pumped to the same mixer. Both pump speeds are adjusted to ensure that the correct ratio of the two phases is delivered to the mixer. After a short residence time in the mixer, the mass is passed to a cutter, which in turn cuts it into the required sized pieces or chunks. The

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chunks fall from the cutter into the calcium setting bath and immediately acquire a skin of calcium alginate. During its passage along the setting bath, the strength and thickness of the alginate skin increases. At the same time calcium ions from the calcium sulphate are released since more water is available in the alginate phase for them to dissolve and as this calcium is bound, more calcium becomes available. At the end of the bath the chunks are harvested and moved by conveyor belt to the canning station. Here they are weight-filled into the cans and a liquid preparation to make gravy or surrounding gel matrix is added. The cans are sealed and sent to a sterilizer. Sterilization is either by static or rotating retort. During the retorting process, the alginate–calcium reaction is completed. At the same time the meat pieces loose liquid, which is mopped up by the guar gum and the gravy. Some pet foods contain the alginate/meat chunks in gravy and some in a gel. In the latter case a carrageenan/LBG combination is often the gelling system used. Combination Setting—Acid pH With acidic products, a spherical fruit such as cherry can be formed using the combination setting technique. Again, a two-phase system is used together with a calcium setting bath. Restructured Cherries These cherries are made by entrapping a cheery puree within a calcium alginate gel formed by the interaction of sodium alginate and calcium ions. The cherries can be produced with a standard shape and weight (i.e., good portion control). They have a texture that closely matches that of canned cherries and they can withstand cooking, freezing, and thawing. A system for making restructured cherries is shown in Figure 8.16. The alginate phase contains the alginate, sugar, a sequestrant, DCP, and water. The fruit phase, the acidic phase, contains the fruit puree, sugar, and water. The two phases are pumped together at the correct ratio into a high-speed mixer and cut off as pieces beneath the surface of the acid setting bath. Setting of the alginate occurs from both the outside of the sphere as well as from the inside. Once hard, the spheres are harvested for further processing. A system for restructured cherries is shown in Figure 8.16. A formulation for restructured cherries is given in Table 8.23.

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Puree phase Alginate phase Pump

Pump Cutter

Harvest

Mixer

Setting bath

Figure 8.16. System for restructured combination set sherries.

Table 8.23. Restructured cherry formulation. Phase

Ingredients

%

Alginate

Water Sugar Sodium alginate (high G, high viscosity) Disodium hydrogen orthophosphate Total (%)

29.03 20.00 0.80 0.07 49.90

Fruit

Cherry puree Sugar Potassium sorbate Total (%)

35.00 15.00 0.10 50.1

Setting Bath

Water Sugar Calcium lactate pentahydrate Malic acid Total (%)

64.60 30.00 5.00 0.40 100.00

G, guluronic acid.

Preparation Alginate Phase 1. Blend together the sodium alginate, sequestrant, and about one-third of the sugar.

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2. Dissolve this mix in the water using a high-speed or high-shear mixer. 3. Once the alginates have hydrated, add the remainder of the sugar and mix until the homogeneous solution has been formed. Puree Phase 1. Mix the sugar into the cherry puree using a high-speed mixer. Extrusion 1. Blend the two phases together with a high-speed mixer for about 30 seconds. 2. Extrude as small spheres (5–10 g each) into the setting bath. 3. After about 10 minutes, the cherries will have a strong skin and can be removed from the bath. 4. Process further as required. The Cost Benefits of Restructuring Foodstuffs 1. One needs to evaluate the cost of any specialized machinery needed to do the restructuring process. Usually this requires a specific payback time coupled with a guaranteed market share and optimal production efficiency. Once the calculations have been done, it is up to the company concerned to make the final decision. 2. Raw material usage is optimized by using restructuring technology. Much less wastage is generated using this rather than many conventional technologies. This, coupled with advances in cutting/dicing machines that now offer the opportunity for “scrapless” cutters, helps to optimize raw material usage as well as to minimize rework. 3. Restructuring provides a means of excellent portion control—control of shape, size, weight, calorific content, and texture. Thus each piece of restructured product can be guaranteed, within certain specified limits, to be the same as the next one. 4. Restructuring permits one to design products for specific applications, heat treatments, and preservation treatments all of which have been discussed earlier.

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SWOT Analysis Strengths

Weaknesses

• Simple chemistry • Efficient raw material use • Less wastage • Products already on the market

• Specialized machinery • Development costs • Relatively unexploited

Opportunities • New products • Creativity • Products for specific uses and/or preservation types • Relatively unexploited • Versatility

Threats • Additives on the label • Lack of enthusiasm • Lost potential/market share

Strengths 1. The chemistry of the alginate gelation reaction is relatively simple. Once the type of alginate and gelling system has been decided upon it is just a matter of controlling the rate of the gelling reaction using the appropriate sequestrants. 2. Restructuring provides a means of fully utilizing all of the raw materials (including pieces) that might otherwise have been wasted. Apart from meat (where it is inadvisable to use >20% fat) and vegetables and fruit (that have to be pitted) most of the processes make full use of the raw materials. Obviously, systems can be designed to use only off-cuts if necessary. 3. Overall there is much less wastage of raw materials. This equates to a cost saving. 4. Products already on the market or that have been on the market include: a. Fruits – Pasteurized fruit pieces in a sauce in glass jars – Used in chilled dairy products and ice creams b. Pimiento strip for stuffing into olives c. Meat products d. Dehydrated vegetables for instant soups and meals

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Weaknesses 1. First, the perceived weaknesses of restructuring is the need for specialized machinery. The authors can put interested parties in contact with a supplier of much of the machinery. 2. In common with all new products there will be development-tomarket costs for the product itself, for scale-up, for market tests, and for machinery. In general, these costs should not be greater than for any other new product development. 3. Some companies are reluctant to be the first with a new product, preferring to wait and see what and how the competitor is doing before deciding upon their own course of action. This can lead to lack of market share and a game of “catch-up.” Opportunities 1. Restructuring foodstuffs provides an opportunity to make new food products that: a. Could not be made and/or processed using conventional technology b. Make more efficient use of raw materials c. Could not withstand normal processing conditions 2. Restructuring provides an opportunity to develop new products to: a. Fulfill potential market needs b. Generate products that cannot be made by existing technology 3. Restructuring allows that product developer to design products for specific applications: a. Especially where an existing product is deficient in some aspect (e.g., some dehydrated vegetable materials will not hydrate optimally or have the right texture when rehydrated under the conditions used) b. For new applications which have not been exploited previously 4. Restructuring provides true versatility to the product developer. For example, a piece of fruit such as a peach cannot be pasteurized without suffering some irreversible textural change. By using a restructured approach, a peach piece can be designed to experience minimal change under the same conditions.

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Threats 1. Some companies wish to use “clean labeling” where only “natural” food products are used and appear on the ingredients list. Restructured foods, by their very definition, require the use of “additives,” all of which are GRAS approved in the United States or have an E. number within the European Community. The decision is all about choice, progress, and a company’s standpoint on these issues. One cannot expect to push back the conventional barriers unless one looks outside conventional thought and ideas. 2. Some companies are in the “race to be second” by relying on their competitors to test the market with new ideas before committing themselves. This attitude or lack of enthusiasm or strategy could result in a loss of new market share and growth potential. Summary of alginate gelation techniques 1. Choose the alginate that is most appropriate for the application. 2. Ensure that the viscosity of the alginate and the phases can be handled by the equipment. 3. Ensure that the alginate is fully hydrated before it is used to form a gel. Partially unhydrated alginate will form gels with less than optimal properties. 4. Check that the alginate and the other reactants are in the correct proportions. Failure to do so may result in gels with less than optimal properties. 5. Once all of the reactants are mixed together do not disturb the setting gel. If a setting gel is disturbed, shaken, mixed, or broken it will not set up properly and will suffer from defects such as low gel strength and/or excessive syneresis. 6. When designing the formulation ensure that the pH does not go below 3.8. Alginic acid is precipitated at pH <3.8 and any calcium alginate gel that has formed will be changed into alginic acid. Acknowledgement The authors thank ISP for permission to use some of the formulations and photographs. In particular, the Restructured Meat System #2 is a patented process belonging to ISP.

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Reference Rees D.A. 1987. Alginate Products for Scientific Water Control. 3rd ed. Structured Foods with the Algin/Calcium Reaction. Tech bull F-85, Kelco. San Diego, California.

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Chapter 9 Hydrocolloids in Flavor Stabilization Milda E. Embuscado

Introduction Protecting aroma and flavors in food products is a very important but challenging task. Taste and appearance make food products desirable. These quality factors propel the popularity of food products and drive the consumers to purchase them. The excellent taste (great flavor and aroma) and attractive appearance of food products will ensure repeat buyers for these products. During manufacture and storage, the flavors in food products are exposed to a variety of conditions that reduce its potency or alter its flavor profile. Flavors are exposed to heat, stress and pressure, moisture, other solvents, ingredients, and packaging materials that can change and bind flavors. Some of these substances can interact with the flavors during processing. The flavors in food products will experience further degradation during transport, storage, and immediately before consumption (through cycles of heating and cooling, microwaving, grilling, and dissolution). It is therefore essential to stabilize and protect the flavors before they are added to food products. Flavors can be classified into several groups: essential oils, oleoresins, tinctures and extracts, savory flavors, thermal process flavors,

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dairy flavors, fruit flavors, flavor modifiers and enhancers and compounded flavors, and natural and artificial flavors. The typical solvents used for flavors are hydrophobic (oil-based) or hydrophilic (water- or alcohol-based). The majority of flavors are complex in nature and are composed of a number of compounds, most of which are highly volatile. When these flavors are added directly to food, most of their volatile components are lost on processing. Stabilization and protecting flavors are very essential steps prior to processing. On the other hand, the release of flavors should occur at the appropriate time. The flavors should be adequately stabilized and protected so as to minimize losses during handling, processing, and storage, but at the same time the flavor release should be correctly timed for the consumer to savor the product. The correct choice of flavor matrix is quite critical. The most important groups of ingredients used in stabilizing and protecting flavors are the hydrocolloids. Hydrocolloids are hydrophilic polymers that are extracted from plants and animals. Hydrocolloids can also be obtained through biotechnological processes such as in xanthan or curdlan gum production. Some hydrocolloids are subjected to modification processes using physicochemical and biochemical methods to improve their encapsulating properties. The materials used to protect flavors are typically film-forming, bland ingredients that are soluble and nonhygroscopic. These ingredients can be grouped into four major groups: 1. Polysaccharides or hydrocolloids—Starch, algin and alginates, agar and agarose, pectins, carrageenan, gum arabic, galactomannans, cellulose and cellulose derivatives (methyl- and ethyl-cellulose and carboxymethylcellulose), maltodextrins, other gums 2. Proteins—Gelatin, casein, zein, whey, soy, and albumin. Proteins are sometimes grouped as hydrocolloids with polysaccharides and other gums 3. Fats and fatty acids—Mono-, di-, and triglycerides, lauric, capric, palmitic, and stearic acids and their salts 4. Waxes—Shellac, polyethylene glycol, carnauba wax, or beeswax This chapter primarily concentrates on polysaccharides, but some important proteins will also be included.

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Hydrocolloids Used in Stabilizing and Protecting Flavors Modified Starches One of the most common and abundant hydrocolloids is starch, the major carbohydrate constituent of corn, rice, wheat, potatoes, tapioca, and other agricultural crops. Starch is a relatively cheap and abundant hydrocolloid. For this reason, a number of ingredients used to protect flavors are derived from starch. Table 9.1 lists the different modified starches that are used to protect and encapsulate flavors. Starch is a mixture of two polymers of glucose, amylose and amylopectin (Figure 9.1). Amylose is a predominantly linear polymer of approximately 250–20,000 ␣-(1→4)-D-glucose units. Its molecular weight is between 40,000 and 340,000. Amylopectin is a highly branched molecule [␣-(1→6) branching of the amylose-type ␣-(1→4)-D-glucose] with molecular weight as high as 80 million. Although an amylopectin molecule has up to two million glucose residues, its structure is quite compact. This compact structure of amylopectin has an effect on its physicochemical and functional properties (e.g., viscosity and appearance). The amylose and

Table 9.1. Modified starches used to stabilize and protect flavors. Name

Usage Levels

Volatile Oil Loading

Dextrinized OSAn waxy cornstarch Dextrinized OSAn tapioca cornstarch Dextrins from cornstarch or tapioca OSAn waxy cornstarch (enzymatically hydrolyzed) OSAn waxy cornstarch (acid hydrolyzed) Maltodextrins OSAn starch + corn syrup solids Absorbent cornstarch

Up to 50% solids

20–25%

Up to 50% solids

20–25%

Up to 50% solids

20–25%

Up to 50% solids

20–25%

Up to 50% solids

20–25%

Up to 50% solids

About 10% flavor 20–25% Up to 50% depending on flavor and solvent

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Hydrocolloids in Food Processing CH2OH H H O

H H OH

H

H

OH

H

OH

H

H

OH

CH2OH O

CH2OH

O

O

H H O

H

H

OH

O

CH2OH H

H H O

H

OH

O

OH

H

H

OH

CH2 H

H H O

CH2OH O

OH

H

H

OH

H

H H O

O

OH

H

H

OH

CH2OH H

H H O

O

OH

H

H

OH

H O

Amylopectin CH2OH H

O H OH

H

H

OH

CH2OH H

H H O

O

OH

H

H

OH

CH2OH H

H H O

O

OH

H

H

OH

CH2OH H

H H O

O

OH

H

H

OH

CH2OH H

H H O

O

OH

H

H

OH

H O

Amylose

Figure 9.1. Starch polymers—amylose and amylopectin.

amylopectin contents of starches from different sources are shown in Table 9.2. Any of these starches can be used to prepare emulsifying starches but a number of emulsifying starches are derived from waxy cornstarch. The amylopectin structure, the main starch component in waxy cornstarch, makes it an ideal choice. The structure and properties of gum arabic is used as the model or reference in preparing emulsifying agents. Gum arabic is a highly branched and compact arabinogalactan that exhibits low viscosity at high solids concentration. This property is taken as a guideline in producing emulsifying starches (Figure 9.2). Native starches do not have emulsifying properties. In addition, the starch molecule is too large to form an enclosure around the very small oil particles in an emulsion. The unmodified starch dispersion is also too viscous when cooked and would be an impractical choice for homogenization and spray drying. The starch molecule is thus chemically modified, and so hydrophobic groups can be attached to the molecule. One popular reaction employed to prepare emulsifying starches is through succinylation or esterification of starch using n-octenyl succinic anhydride (OSAn). The starch slurry is treated with 3% OSAn at an appropriate pH and temperature to produce granular OSAn Figure 9.3). The maximum amount of OSAn that can be added is 3% as set forth in

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Table 9.2. Components and properties of different starches.

Source

%Amylose %Amylopectin

Granule Size (␮)

Common corn

25

75

5–20

Waxy corn

1–5

95–99

High amylose

50–75

25–50

5–15

Potato

20

80

15–100

Waxy potato∗

<1

Rice

20

80

Waxy rice

2

98

Tapioca

15–18

82–85

5–35

Wheat

25

75

5–15 2–3

5–100 3–8

Granule Shape Irregular polyhedron Irregularly shaped granules Irregularly shaped with smooth edges Large smooth round oval granules Large smooth oval granules Irregularly shaped polygons Irregularly shaped polygons Irregular smooth spheres

∗

Source: Avebe/Farbest (New Jersey). Avebe is the exclusive manufacturer of waxy potato starch.

the Code of Federal Regulations (21 CFR 172.892). After washing and drying, the OSAn starch undergoes hydrolysis to reduce the size of the starch molecules into ideal lengths for emulsification. The hydrolytic processes employed are dextrinization, acid hydrolysis, enzyme hydrolysis, or a combination of these processes. These are the basic steps employed in the production of OSAn starches but some starch companies alter the sequence to obtain unique OSAn starch products or to adapt to their manufacturing facilities. The OSAn starches listed in Table 9.1 have undergone either dextrinization or acid/enzyme hydrolysis to reduce the long polymers of glucose into shorter chain lengths. Dextrinization is accomplished by roasting the OSAn starch at high temperatures in the presence of an acid for a predetermined time. This

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Hydrocolloids in Food Processing 1600 1400

Viscosity (cP)

1200 1000 800 600 400 200 0 10

20

30 Total solids (%)

Dextrinized OSAn

40

50

Gum arabic

Figure 9.2. Viscosity of gum arabic at various percentages of solids as compared with a dextrinized octenyl succinic anhydride (OSAn) starch.

Waxy starch slurry

+ Octenyl succinic anhydride

Succinylation

OSAn starch (granular) Esterified waxy starch with lipophilic and hydrophilic components

Figure 9.3. Esterification of starch using octenyl succinic anhydride (OSAn).

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process produces a tan-colored OSAn starch product. The longer the time of dextrinization or the higher the temperature or concentration of the acid used, the darker the color of the dextrinized OSAn starches. Dextrinized OSAn starches have very good emulsifying properties. The length and molecular structure of the starch molecule are ideal for emulsification. However, the roasting process produces some off-odors and off-flavors in dextrinized OSAn starches, which make them unsuitable for some delicate flavors. Acid and enzyme hydrolyzed OSAn starches are white in color and are bland and these OSAn starches are ideal emulsifying ingredients for delicate and fruit flavors. In addition to the molecular length and shape of the OSAn starch, the degree of substitution and the position of the OSAn are also critical for its emulsification properties. Typically, a 2% OSAn degree of substitution or higher is targeted, but some OSAn products have less than 2% bound OSAn. The choice of the right OSAn starch will depend on the type of flavor and the solvent used in the liquid flavor. The flavorist or product developer must be familiar with these critical properties of OSAn starches to be able to choose the right starch for the right flavor. Strong flavors like the oleoresins can be encapsulated in dextrinized OSAn starches without masking its flavor or interfering with their flavor profiles or its flavor delivery. Dairy and delicate flavors like fruit flavors should be stabilized using acid- or enzyme-hydrolyzed OSAn starches, which are bland and have minimal off-odor and metallic or chemical taste. Gums and Modified Gums Another group of hydrocolloids used to stabilize and protect flavors are the gums and modified gums. Gum arabic is the most popular gum used for flavor encapsulation. It is prepared from the gummy exudate flowing naturally or obtained by incision from the stems and branches of Acacia senegal and Acacia seyal trees. These trees grow on the Sahelian belt of Africa and the gum has been in use for more than 5,000 years. Gum arabic or acacia gum is a natural film-forming gum widely used to stabilize flavors and essential oils. It is also used to prepare flavor concentrate emulsions for beverages. It is a mixture of high molecular weight arabinogalactan heteropolymers and about 2% proteinaceous component attached covalently to the polysaccharide component (Dickinson et al. 1989). The average molecular weight is

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between 300,000 and 800,000, and the major sugar components of this polysaccharide are galactose, arabinose, rhamnose, and glucuronic acid. The excellent emulsification and stabilization properties of gum arabic are due to its hydrophilic carbohydrate, hydrophobic protein component, and its molecular flexibility, which permits greater surface interaction with the oil particles. The compact structure of gum arabic permits the preparation of high total solids solutions with very low viscosity compared to other hydrocolloids. This low viscosity at high solids content is desirable for spray drying operation. Gum arabic is pH stable and provides good retention of volatiles during spray drying (Thevenet 1988, 1995). The basic steps involved in the manufacture of gum arabic are tapping the acacia trees by means of incisions made on their branches and collecting the gum droplet exudates from the trees. The yield from each tree varies from 500 grams to several kilograms depending on the age of the trees. The gum exudates are then cleaned and ground. The typical grades of gum arabic are as follows (AIPG 2005): 1. Hand picked and selected—This demands the highest price and is the most expensive, lightest in color, and cleanest acacia gum and comes only from large nodules. 2. Cleaned and sifted—This is the material that remains after selecting the large nodules. These are the whole or broken lumps that are pale or amber-colored exudates. 3. Cleaned—This is the standard grade varying from light to amber in color. 4. Siftings—The fine particles left after grades 1–3 of acacia gum have been selected. 5. Dust—After the cleaning process, very fine particles that contain sand and dirt are collected. The first grade is highest in quality, and the last one is the poorest in quality. The gum arabic exudates are further processed in the manufacturing plants. They are subjected to quality control testing prior to grinding. At the processing plant, the raw acacia gum is dissolved in water, filtered to remove any contaminants and extraneous materials. The purified acacia gum solution is then heated and spray dried to get a highly purified product. Some companies employ additional processes such as

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agglomeration and additional purification steps to improve the quality and handling of the product. The gum exudates from A. senegal trees are considered the best quality gum for emulsification and flavor encapsulation. However, gum exudates can also be obtained from seyal trees, which have a wider growing area and thus are more widely available than those from the senegal trees. To improve the emulsifying properties of gum acacia from seyal trees, gum acacia is chemically modified (Ward 2002). One of the most functional emulsifiers produced is the OSAn modified gum acacia. This group of emulsifying agents is now commercially available. These products have superior emulsion stability as compared with some OSAn starches and the traditional gum arabic. They also allow solid levels as high as 40%, are cold water–soluble, have excellent oil recovery, and have longer shelf life. They are also derived from a readily available and natural raw material and thus are more cost effective. In 2004, a new innovative gum acacia product was launched; it allows usage at low dosage levels. It is a highly functional gum arabic manufactured using an innovative and proprietary breakthrough process. It is also very soluble in water and allows reduction of gum arabic usage in formulating flavor emulsions. It is a natural, generally recognized as safe (GRAS), and genetically modified organism (GMO)–free ingredient and is labeled as gum arabic in food products. Aside from gum arabic and modified gum arabic, other film- and gelforming hydrocolloids are used to stabilize and protect flavors. Gelatin, galactomannans, carrageenan, cellulose derivatives, and alginates are also used to stabilize flavors. Table 9.3 summarizes the physicochemical properties of these gums and their uses. Methods of Stabilizing and Protecting Flavors Plating of Flavors Plating is defined as coating a thin layer of substance onto a solid surface. In plating of flavors, the conventional solid materials or flavor carriers used are sugars, salts, and maltodextrins. The sugars used for plating are dextrose, fructose, sucrose, and lactose while sodium chloride is the salt of choice. In recent years, other materials have been used to convert the liquid flavors into free-flowing powder. Right now, the definition of plating has been extended to absorption into microporous matrix

224 Heterogeneous mixtures of polypeptides Cellulose derivative

Gelatin

Carboxymethylcellulose

Galactomannan Sulfated galactan

Guar gum Carrageenan

40,000–1,000,000

300–4,000 amino acid residues

220,000 ∼ 3,000,000

310,000

Galactomannan

Locust Bean gum

300,000–800,000

Flavor Stabilization

Emulsifier, texturizer and film Flavor emulsion, former spray drying, coacervation, extrusion Emulsifier and film former Emulsion, spray drying Forms thermally-irreversible Coacervation weak gels Thickener and stabilizer Coacervation Thickening, suspending and Coacervation gelling agent Gelling agent, Coacervation, thermoreversible gelling spray drying agent Thickener, emulsion Coacervation stabilizer

Functionality

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300,000–800,000

Arabinogalactan

Gum arabic

Molecular Weight

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Modified gum arabic

Type

Name

Table 9.3. Gums used in protecting flavors.

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Sodium alginate

∼ 9,000,000

∼ 9,000,000

Form gels on heating Thickener, emulsifier, stabilizer, and foaming agent Thermally stable gelling agent in the presence of calcium ions, stabilizer, emulsifier Thermally stable gelling agent in the presence of calcium ions, stabilizer, emulsifier

Coacervation

Coacervation

Coacervation Coacervation

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Linear unbranched polymers containing mannuronic and guluronic acids Linear unbranched polymers containing mannuronic and guluronic acids

10,000–220,000 10,000–220,000

Cellulose derivative Cellulose derivative

Thickener, emulsifier and Coacervation film former Thickening agent or stabilizer Coacervation

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Potassium alginate

10,000–220,000

Cellulose derivative

Hydroxypropyl methyl cellulose Methyl cellulose Methyl ethyl cellulose

60,000–1,000,000

Cellulose derivative

Hydroxypropyl cellulose

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carrier. Amorphous silicas have been found to be more effective flavor carriers than the traditional carriers (Bolton and Reineccius 1992). The silicas can be plated with as much as twice their weight in flavor and remain dry and free flowing compared to 3–20% plated flavors on salt, sugars, and maltodextrins (Bolton and Reineccius 1992). However, the use of silicas in food is severely regulated making the employment of these flavor carriers not quite viable commercially (Zeller et al. 1999). Starch has long been used as a flavor carrier due to the helical structure of the amylose fraction, which can trap flavor molecules (Solms 1986). Micropores are naturally present in starch granules (Fannon et al. 1992, 1993). Niemann and Meuser (1994) and Yamada et al. (1995) treated the starch granules with amylase enzymes to create more highly porous starch granules. A highly absorbent modified starch from dent cornstarch was developed a few years ago. This highly absorbent modified starch is insoluble in water and can be used to convert aqueous and oil systems into free-flowing powders. It is derived from a common natural ingredient and is label friendly and economical. The photomicrograph of the highly porous and absorbent starch granules is shown in Figure 9.4. Propylene glycol, lecithin, and vegetable oil at 33%

R Figure 9.4. Photomicrographs of Pure-Dent
B730 starch granules.

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B-730

MD 10 DE

227

CSS

R Figure 9.5. Lemon flavor plated in Pure-Dent
B730 as compared with maltodextrin (10 DE) and corn syrup solids.

concentration have been plated on this absorbent starch. Lemon oil flavor was loaded at 40% using the plating starch. Figure 9.5 shows the plated starch with lemon oil as compared with maltodextrin and corn syrup solids plated with the same amount of lemon oil. The final product using the microporous starch was still free flowing while the other two samples were wet and clumped. These samples were also subjected to 400 kPa (8,354 lb/sq ft) of pressure for 5 minutes using a Carver Laboratory Press. At this pressure, any liquid would be expelled out if not absorbed by the carrier. Using this plating starch, a minimal amount of liquid was released. This suggests that these solvents/liquids will not be easily released during processing or storage when plated on this modified absorbent starch. Different types of flavors as high as 40% can be plated on this modified starch product. Plating flavors on this type of starch has numerous application potentials and cost benefits. Flavor Encapsulation through Spray Drying Spray drying of flavor emulsions is one of the most common techniques used to manufacture encapsulated flavors. It is an effective method of stabilizing and protecting flavors. Stabilization of flavors is accomplished by coating the liquid flavor with a thin protective layer of wall material when the emulsion undergoes rapid drying. This wall material prevents volatilization and chemical degradation of flavor components. In addition to stabilization and protection of flavors, encapsulation is also used to convert the liquid flavor into a dry and free-flowing form.

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Hydrocolloids in Food Processing Dissolve ingredients in water. (OSAn starch or gum arabic, maltodextrin, sugars, etc.) Add flavor (in oilbased solvent).

Homogenize

Pre-emulsion

Homogenize

Emulsion (Check particle size, viscosity).

Spray dry (Check particle size, flavor load, other flavor components, moisture, sensory and powder properties).

Figure 9.6. Flavor encapsulation through spray drying.

The wall material controls the release of the flavor, improves the physicochemical and handling properties of the flavor, improves its safety, and improves its visual and textural appearance. The basic steps involved in flavor encapsulation by spray drying are shown in Figure 9.6. The dry ingredients are dissolved or dispersed completely in preweighed water, high molecular weight ingredients first (e.g., starches, gums), then sugars or maltodextrins. Complete dissolution of the starches, gums, and other ingredients are important to obtain the full functionality of these ingredients. It is beneficial if the water is heated to 30–40◦ C before adding the starch and other dry ingredients to facilitate dispersion and dissolution. Higher temperatures can be used if the flavor components are not highly volatile or are as volatile as dimethyl sulfide or diacetyl.

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Using higher total solids will be more cost effective because there will be less water to evaporate. Thus, it is important to use the highest total solids possible, provided that the emulsion will not be very viscous that it cannot be fed into the spray dryer. It is beneficial to optimize the flavor carrier matrix and the processing conditions for each type of flavor in order to get the best quality of encapsulated flavors. Once all of the dry ingredients are in the solution, the flavor in the oil or other solvent is added and the mixture is prehomogenized; then it passed through the homogenizer once or twice depending on the nature of the flavor and emulsion. The particle size distribution of the emulsion is checked especially if this is the first time this encapsulated product is being produced commercially. The emulsion is spray dried at established an feed rate and at established inlet and outlet drying conditions for this encapsulated product. The final product is tested for moisture, flavor load, and other components critical to its flavor profile (e.g., limonene content for lemon oil) using gas or high performance liquid chromatography. The product also needs to pass sensory evaluation and microbiological examination before it is released to the customer. The modified starches used for flavor encapsulation are shown in Table 9.1, the gums are shown in Table 9.3, and the formulations are shown in Appendix A. The choice of flavor carrier will depend upon the type of flavor and the solvent used. The critical parameters to measure and monitor are the particle size distribution, the rheological properties, and the visual appearance of the emulsion. Typical operating conditions involve a 30–50% feed under inlet and outlet drying conditions of 150–180◦ C and 75–95◦ C, respectively (Master 2002). Monitoring and maintaining the appropriate processing temperatures and feed rates are critical because of the highly volatile nature of the flavor components. A number of studies have been conducted to determine the efficiency of different carriers in encapsulating flavors (Sharma 1981; Saleeb and Pickup 1985; Bangs and Reineccius 1990; Boskovic et al. 1992; Shahidi and Han 1993; Morehouse 1994; Kim and Morr 1996; Subramaniam 1996; Desobry et al. 1997; McNamee et al. 1998; Buffo and Reineccius 2000; Subramaniam et al. 2004). Gum arabic is typically used as the gold standard or reference when evaluating a flavor encapsulation ingredient although OSAn starches have gained some popularity because of their unique functionality. Figure 9.7 shows the initial particle size of lemon oil emulsion using a dextrinized OSAn starch with different concentrations of maltodextrin. It appears that using a higher

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Particle size (microns)

12 10 8 6 4 2 0 d(0.10)

d(0.5)

d(0.9)

Span

% Particle size and span OSAn dextrinized-maltodextrin (50:50)

OSAn dextrinized-maltodextrin (60:40)

Figure 9.7. Effect of addition of maltodextrin on the particle size of lemon oil emulsion stabilized by a dextrinized octenyl succinic anhydride (OSAn) starch.

concentration of maltodextrin produced a small particle size distribution and span. The smaller the particle size, the more stable the emulsion and the better the quality of the encapsulated product. Apart from the particle size, the encapsulated flavor samples are also subjected to analytical and sensory evaluation, and these quality parameters are monitored at 25◦ C and at accelerated temperatures, typically at 40◦ or 50◦ C. Figure 9.8 shows the comparative flavor load and percentage of limonene of OSAn starch without and with an additive (fiber and maltodextrin). OSAn starch with 2.75% fiber had higher percentages of flavor load and limonene content. One important tool that can be used to evaluate the flavor particles after spray drying is the scanning electron microscopy (SEM). It is a very helpful tool to determine if the encapsulating ingredient has formed a fully functional protective wall around the flavor droplet. Figures 9.9–9.10 show the shapes and the surface of the encapsulated lemon oil particles. Particles of lemon oil encapsulated using a dextrinized OSAn starch show smooth surface with minute holes and fewer shrunken spheres. Those encapsulated in gum arabic have more shrunken

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35.0 30.0

Percentage

25.0 20.0 15.0 10.0 5.0 0.0 % VOSD % Limonene % volatile oil or % limonene content OSAn starch OSAn starch + fiber (2.75%)

OSAn starch + fiber (1.37%) OSAn starch + maltodextrin (55%)

OSAn starch + fiber (2.06%)

Figure 9.8. Stability of lemon oil in octenyl succinic anhydride (OSAn) starch with fiber and maltodextrin as compared with pure OSAn starch as a stabilizer. VOSD, volatile oil by steam distillation.

particles and the wall appears more porous. Ideally the wall must be dense with fewer holes and the surface of the particles must be smooth. There must also be fewer shrunken particles. To improve the structure of the walls in encapsulated flavors, it will be necessary to optimize the processing conditions used (homogenization and drying temperatures) for each type of flavor. In addition, the composition of the wall material must be optimized so that the wall or layer formed around the flavor oil is more compact and has a smoother surface. This type of wall material will prevent volatilization of the flavors and will protect the flavors during food application process and product storage. Depending on the type of flavor being encapsulated, it might be necessary to incorporate lower molecular weight carbohydrates like sugars and maltodextrins to optimize carrier matrix structure to make it strong, dense, and free from cracks and holes. Spray drying is an extremely cost-effective and widely accepted flavor encapsulation process. It can be used to encapsulate a number of flavor substances (Uhlemann et al. 2002). The encapsulated flavor can also be agglomerated to improve the dissolution of the product.

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Figure 9.9. Photomicrographs of lemon oil encapsulated in gum arabic.

Extrusion Extrusion is another technique used in encapsulating flavors. In extrusion, the flavors are trapped when the melted flavor carrier matrix forms an impermeable glass as it exits the extruder and cools down. Appendix B provides examples of encapsulated flavors prepared through extrusion. In addition to low molecular weight carbohydrates, hydrocolloids are important ingredients used in extrusion processes. Modified starches and maltodextrins are commonly used as components of the carrier

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Figure 9.10. Photomicrographs of lemon oil encapsulated in dextrinized starch.

matrix. After the addition of a plasticizer (e.g., water), the carrier matrix is melted, the liquid flavor is added, and the highly viscous mass is forced through the extruder die hole plate under high pressure. As the melted mass exits the extruder, the extrudate quickly cools down and solidifies into an amorphous glass. After the mass has completely cooled down, it is ground into suitable size and a flow agent is typically added. Selection of the components of the matrix is based on the physicochemical properties of the ingredients, the most important of

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which are the glass transition temperature, the viscosity of the mass at extrusion temperatures, and expansion of the mass when it cools down. The expansion of the matrix should be minimal. The integrity of the extruded particle is also important. The extruded strand should be strong enough so as not to disintegrate on pressure to produce fine particles but not rock hard that it cannot be easily grounded into smaller particles. The extrusion process is suitable for highly sensitive flavors like the citrus oils. The extruded matrix with citrus oil has been found to have a longer shelf life and better protection against oxidation (Uhlemann et al. 2002). But like spray drying, the extrusion process has its problems, which can result in the reduction of the shelf life of the product. Flavor components can be lost due to structural defects, cracks, and thin walls and pores formed during and after processing (Zeller et al. 1999). Coacervation Coacervation is defined as the separation of colloidal solutions into two liquid phases upon alteration of the system’s thermodynamic condition. Two products are obtained from this process: a coacervate, which is rich in colloid, and the second phase that has a poor colloid concentration. The first commercial application of coacervation was the development of “carbonless” carbon copy (no-carbon-required, NCR, paper) by the National Register Company in the 1950s. Three steps are involved in the process of coacervation. These are the formation of the droplet, skin or wall formation around the droplet, and isolation of the particle. There are a number of ways of initiating coacervation. Changing the temperature, the pH, or adding a second substance can trigger formation of a skin that envelopes the flavor particles or droplets. Gum arabic or gelatin are typically used to prepare coacervates, and this is the system most studied. The first step is emulsification of the core material in the gelatin or gum arabic solution. Next is the addition of the gelatin or the gum arabic solution into the system. The gelatin solution is added if gum arabic was used to suspend the core material or vice versa. The pH is adjusted to 3.8–4.3 with continuous mixing and the system is cooled down. The gelled capsule walls are cured by adding glutaraldehyde or another hardening agent or cross-linking agent, then the microcapsules are collected and dried after thorough washing. Preparation of microcapsules through coacervation

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is an expensive process and requires expensive and precise equipment, especially if a specific range of size of microcapsules is being prepared. Applications of flavor coacervates include chewing gum, instant soups and sauces, spreads, baked goods, and cereals (Uhlemann et al. 2002). Cellulose gums and alginates have also been used in coacervation. Table 9.3 lists some of the hydrocolloids that have been tested in preparing flavor coacervates.

Resources on the Web for Hydrocolloids Used to Stabilize and Protect Flavors Table 9.4 lists the resources on the web on hydrocolloids. These web sites of the government agencies, universities, and organization provide a wealth of information about government regulations, current regulatory status of ingredients, physicochemical and functional properties of hydrocolloids, recent advances on flavor encapsulation and microencapsulation.

236

Universities, government agencies, organizations

Joint FAO/WHO Expert Committee on Food Additives (JECFA) US Food and Drug Administration The Association for the International Promotion of Gum (AIPG) Southwest Research Institute

www.swri.edu

www.treegums.org

Southwest Research Institute (SwRI) is an independent, nonprofit applied research and development organization.

Approval, code of federal regulations List of members, gum arabic manufacture, grades of gum arabic

Acceptable daily intake (ADI)—not specified

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INS: 414 gum arabic

Oregon State University

http://food.oregonstate. edu/gums/arabic.html http://jecfa.ilsi.org/

Physicochemical and functional properties, molecular structure

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www.fda.gov

Gum arabic

Author—Martin Chaplin London South Bank University

http://www.lsbu.ac.uk/ water/hyarabic.html

Hydrocolloids: Water structure and behavior

Table 9.3. Hydrocolloids used to stabilize and protect flavor—resources on the web.

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Appendix A – Flavor Encapsulation Formulations Spray-dried orange oil formula (Tate & Lyle website) OSAn cornstarch Flavor oil Water

27.00% 11.00% 62.00% 100.00%

Spray-dried orange drink mix (Grain Processing Corporation website) Orange juice concentrate Maltodextrin 10 DE Water Citric acid Calcium phosphate Sodium citrate Orange flavor

30.00% 28.50% 40.00% 1.00% 0.12% 0.12% 0.26% 100.00%

Spray-dried flavor (National Starch website) Dextrinized OSAn cornstarch or tapioca starch Flavor oil Water

36.36% 9.09% 54.55% 100.00%

Spray-dried flavor (National Starch website) OSAn cornstarch Flavor oil Water

24.00% 16.00% 60.00% 100.00%

Spray-dried flavor (National Starch website) OSAn cornstarch + corn syrup solids Flavor oil Water

32.00% 8.00% 60.00% 100.00%

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Appendix B – Examples of Flavors Encapsulated through Extrusion Preparation of solid essential oil flavor composition (US Patent by Miller et al. 1986) Starch hydrolyzate Sugar Emulsifier Cold-pressed orange oil

41.30% 28.27% 1.64% 28.79% 100.00%

Encapsulation matrix composition and encapsulate containing same (Barnes et al. 1987) Maltodextrin Dextrinized OSAn cornstarch Emulsifier Water Orange juice 58◦ C conc.

40.35% 10.09% 0.86% 38.79% 9.91% 100.00%

Solid essential oil flavor encapsulation (US Patent by Miller et al. 1987) Starch hydrolyzate Sugar Emulsifier Cold-pressed orange oil

48.01% 32.87% 1.59% 17.53% 100.00%

Fixation of volatiles in extruded glass substrates (US Patent by Saleeb et al. 1989) Mannose Maltodextrin 10 DE Lemon oil

24.04% 72.12% 3.85% 100.00%

The mixture was extruded in a Brabender extruder using the following conditions: temperature at Zone I, 60◦ C; Zone II, 120◦ C; Zone III, 130◦ C and Die, 125◦ C.

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Controlled release encapsulation compositions (US Patent by Black et al. 1998) Matrix (modified starch, whey or soy protein) Sucrose Maltodextrin

50.00% 25.00% 25.00% 100.00%

Cinnamon flavor was plated on the dry matrix, a sufficient plasticizer was added, the mixture was heated under pressure, and the plastic mass was extruded. Particulate flavor compositions and process to prepare same (US Patent by Blake et al. 2002) Saccharose Maltodextrin 2 DE Water Orange oil Lecithin

42.6% 42.6% 4.3% 10.0% 0.5% 100.00%

The mixed ingredients were fed into a twin-screw cooker/extruder and heated to 150◦ C at the central section of the extruder and 95◦ C at the die face. Solid delivery systems for aroma ingredients (US Patent by Mutka et al. 2003) Maltodextrin 18 DE Sucrose Sucralose Lecithin Lemon oil Water

38.41% 13.67% 23.42% 0.67% 7.17% 16.67% 100.00%

The maltodextrin, sucrose, and Sucralose RTM were dissolved in water and heated to 118◦ C to reduce the moisture to approximately 6%. The mixture was extruded three times through a die plate with 1 mm holes. A 1% silicon dioxide was added as flow agent.

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Process for the preparation of granules for the controlled release of volatile compounds (US Patent by Benczedi et al. 2003) Maltodextrin 19 DE Lecithin Water Strawberry flavor

90.00% 1.00% 6.00% 3.00% 100.00%

Encapsulation composition (US Patent by Porzio et al. 2003) Matrix Maltodextrin 10 DE Corn syrup solids 42 DE Methyl cellulose (Methocel A4M)

72.50% 20.00% 7.50% 100.00%

Orange oil was injected at 12 mL/min to retain an 8.30% load in the final extruded product which contained 8.9% moisture.

Acknowledgment I thank Saulo Embuscado for preparing all of the figures in this chapter. References Bangs W.E. and Reineccius G.A. 1990. Characterization of selected materials for lemon oil encapsulation by spray drying. J Food Sci, 55(5):1356–1358. Barnes J.M. and Steinke J.A. 1987. Encapsulation matrix composition and encapsulate containing same. US Patent 4,689,235. Black M., Popplewell L.M., and Porzio M.A. 1998. Controlled release encapsulation compositions. US Patent 5,756,136. Blake A. and Attwool P. 2002. Particulate flavor compositions and process to prepare the same. US Patent RE37,860. Bolton T.A. and Reineccius G.A. 1992. The oxidative stability and retention of a limonene-based model flavor plated on amorphous silica and other selected carriers. Perfumer & Flavorist, 17(2):1–12. Boskovic M.A., Vidal S.M., and Saleeb F.Z. 1992. Spray-dried fixed flavorants in carbohydrate substrate and process. US Patent 5,124,162. Buffo R. and Reineccius G. 2000. Optimization of gum acacia/modified starch/maltodextrin for spray drying of flavors. Perfumer & Flavorist, 25(3): 37–51.

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Desobry S.A., Netto F.M., and Labuza T.P. 1997. Comparison of spray-drying, drumdrying and freeze-drying for ß-carotene encapsulation and preservation. J Food Sci, 62:1158–1162. Dickinson E., Elverson D.J., and Murray B.S. 1989. On the film-forming and emulsionstabilizing properties of gum arabic: dilution and flocculation aspects. Food Hydrocolloids, 3(2):101–114. Fannon J.E., Hauber R.J., and BeMiller J.N. 1992. Surface pores of starch granules. Cereal Chemistry, 69(3):284–288. Fannon J.E., Shull J.M., and BeMiller J.N. 1993. Interior channels of starch granules. Cereal Chemistry, 70(5):611–613. Kim Y.D. and Morr C.V. 1996. Microencapsulation properties of gum arabic and several food proteins: spray-dried orange oil emulsion particles. J Agric Food Chem, 44:1314–1320. Master K. 2002. Chapter 10—Product applications in the manufacturing industries. In: Spray Drying in Practice. SprayDryConsult International ApS: Denmark, p. 385. McNamee B.F., O’Riordan E.D., and O’Sullivan M. 1998. J Agric Food Chem, 46:4551–4555. Miller D.H. and Mutka J.R. 1987. Solid essential oil flavor composition. US Patent 4,707,367. Mutka J.R., McIver R.C., Palmer C.A., Benczedi D., Bouquerand, P.E., and Firmenuch A. 2003. Solid delivery systems for aroma ingredients. US Patent 6,607,778. Niemann C. and Meuser F. 1994. Preparation of porous starches using different amylases, paper no. 10, Starch Session, presented at the 79th Annual Meeting of the American Association of Cereal Chemists, Nashville, Tennessee. Porzio M.A., and Popplewell L.M. 2003. Encapsulation compositions. US Patent 6,652,895. Saleeb F.Z. and Pickup J.G. Fixation of volatiles in extruded glass substrates. US Patent 4,820,534. Saleeb F.Z. and Pickup J.G. 1985. Fixing volatiles in an amorphous substrate and products therefrom. US Patent 4,532.145. Shahidi F. and Han X.Q. 1993. Encapsulation of food ingredients. Crit Rev Food Sci Nutr, 33(6):501–547. Sharma S.C. 1981. Gums and hydrocolloids in oil-water emulsion. Food Technol, 35:59–67. Solms J. 1986. Interaction of non-volatile and volatile substances in foods. In: Interactions of Food Components, Birch G.G. and Lindley M.F., editors. Elsevier: London, pp. 189–199. Subramaniam A. 1996. Particulate hydrogenated starch hydrolysate based flavoring materials and use of same. US Patent 5,506,353. Subramaniam A., McIver R.C., Vlad F.J., and Benczedi D. 2004. Spray-dried compositions and method for their preparation. US Patent 6,723,359. The Association for the International Promotions of Gum (AIPG) 2005. www.treegums.org. Thevenet F. 1988. Acacia gums: Stabilizers for flavour encapsulation. In: Flavour Encapsulation, ACS Symposium Series 370, Risch S.J. and Reineccius G.A., editors. American Chemical Society: Washington, DC, pp. 45–54.

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Thevenet F. 1995. Acacia gums: Natural encapsulation agent for food ingredients. In: Encapsulation and Controlled Release of Food Ingredients, ACS Symposium Series 570, Risch S.J. and Reineccius G.A., editors. American Chemical Society: Washington, DC, pp. 51–59. Uhlemann J., Schleifenbaum B., and Bertram H. 2002. Flavor encapsulation technologies: An overview including recent developments. Perfumer & Flavorist, 27(5):52–61. Ward, F.M. 2002. Water-soluble esterified hydrocolloids. US Patent 6,455,512. Yamada T., Hisamatsu M., Teranishi K., Katsuro K., Hasegawa N., and Hayashi T. 1995. Components of the porous maize starch granule prepared by amylase treatment. Starch/Staerke, 46:358–361. Zeller B.L., Saleeb F.Z., and Ludescher R.D. 1999. Trends in development of porous carbohydrate food ingredients for use in flavor encapsulation. Trends Food Sci Technol, 9:389–394.

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Chapter 10 Hydrocolloid Purchasing I: History and Product Grades Thomas R. Laaman

The Difficulties of Purchasing Hydrocolloids The last two chapters of this book are devoted to assisting the technical and purchasing people at food companies in the important hydrocolloid procurement process. Over the years this has often been an admittedly uncertain process. At times it has been complicated to decipher the exact grade needed while also receiving the logistical, technical, and applications support required from suppliers. Getting good market pricing has often been abandoned in pursuit of these other needed objectives. But eventually there is also a delayed frustration when it is realized that the prices that have been paid for 5 or 10 years to a trusted supplier have been far above true market prices. Hydrocolloid procurement has been difficult because practical hydrocolloid use has quite often been difficult. It is not easy to purchase something that is not completely understood. A major goal of this book has been to provide practical explanations, formulations, and procedures for the use of hydrocolloids in a number of food products. The goal in hydrocolloid usage should not only be to gain the desired functionality, but also to do so efficiently and cost effectively. To better understand the purchasing situation for hydrocolloids, let’s compare food hydrocolloids to other food ingredients. Many food ingredients are commodity-type products such as corn syrups, milk proteins, Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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and standardized grades of wheat flours. For most of these products, listings by exact grade can be found in marketing publications together with current prices and even futures pricing. A purchasing agent can easily purchase these products and pay the same amount as other purchasing agents throughout the food industry. Smaller customers would pay some premiums but these would be similar to other customers of the same size. Everyone uses the same standardized grades that are fairly easy to learn, and the prices are tied in to these standardized grades. Also, in many cases, the selling company does not need to provide much technical support because the customer does not require it. The keys involved in selecting a supplier for a food company using a commodity-type ingredient are as follows. First, the research and development department must identify the exact grade needed; and second, the purchasing department must find pricing for that exact grade. The third key is to evaluate suppliers of that grade on the basis of logistics, customer service, and technical support parameters that the customer determines necessary. These same three keys are present in selecting a supplier for any ingredient, but each of the keys are more complicated and tricky for hydrocolloid ingredients.

The Three Keys to Successful Purchasing of Hydrocolloids There are three keys, then, to successfully purchasing hydrocolloids. First, the exact grade needed must be ascertained. Second, a very competitive price must be obtained consistently. Third, the supplier must be identified as one who can produce that exact grade at an attractive price while possessing other desired attributes such as good technical service or nearby product warehousing. The first key, understanding hydrocolloid grades is covered in depth in this chapter. Chapter 11 is devoted to the second and third keys. The three keys can be used to obtain excellent products, prices, and important supplier-provided customer benefits, but this has historically been difficult in the hydrocolloid world. To understand why and to set a basis for contemporary success for companies purchasing hydrocolloids, it is helpful to review the marketing history of hydrocolloids. In order to avoid repeating the mistakes of the past, the past must be understood.

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The Stages of Hydrocolloid History To help facilitate an understanding of the history of hydrocolloid manufacturing and marketing, five key stages of development can be discerned. These five stages will be termed as: beginnings, monopoly, semicompetitive, competitive, and commodity. Before giving some explanation of these historical stages, a few caveats must be mentioned. First, the historical perspective described below is from the point of view of an American food company, although most of the principles apply to food companies buying hydrocolloids in many other countries as well. Second, these stages apply for most of the major hydrocolloids but not for all of them. They apply most closely to hydrocolloids that were heavily manufactured at one time in the United States and Europe. This would include seaweed-based hydrocolloids such as alginate, carrageenan, and agar; cellulose-derivative hydrocolloids such as sodium carboxymethylcellulose (CMC), methylcellulose, and microcrystalline cellulose; and fermentation hydrocolloids such as xanthan gum and gellan gum. Gums largely manufactured traditionally in places like India and Africa such as guar gum and gum arabic are less closely melded to this historical analysis. The third caveat is that the exact time period for each of the five eras differs from hydrocolloid to hydrocolloid. In other words, while one hydrocolloid was already firmly rooted in the semicompetitive phase another was still somewhat entrenched in the monopoly phase, but interestingly, one hydrocolloid being yanked to the next phase did seem to have an influence on other hydrocolloids moving to the next phase as well. Once purchasing agents were made aware of new possibilities for purchasing one of the hydrocolloids in their portfolio they naturally started to consider the same approach for other hydrocolloids. By the same token, once hydrocolloid suppliers saw that some big entrenched monopolies could be taken down, other monopolies were targeted as well.

The Beginnings Era of Hydrocolloid History The beginnings phase began in the late nineteenth century for some hydrocolloids and continued for some hydrocolloids until the

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mid-twentieth century and beyond. Before this phase, several of the hydrocolloids had been used for centuries in unpurified forms. The beginnings phase marked the beginning of the use of commercially manufactured hydrocolloids. As in many other early industries such as the automobile industry, many small companies tried their hand at the manufacturing of hydrocolloids with mixed results. Quality varied tremendously. The technology of manufacturing was still being developed. As is generally the case in these types of situations, a very few companies eventually came to dominate each individual hydrocolloid. This was due to the following factors: (1) companies that learned how to make better quality products in cost efficient ways drove out of business companies who could not do so; (2) when two companies were both capable of being successful, it was usually to the advantage of one company to buy out the other company to eliminate competition and as a means to quickly grow production capacity during a time of rapid growth in sales. These developments helped push the hydrocolloid world to the next era. During the beginnings era, grades and prices were highly variable. Generally grades were fairly simple and applications knowledge was still in its infancy.

The Monopoly Era of Hydrocolloid History Eventually, very few companies were left in each hydrocolloid category, and in specific regions some of these had near or virtual monopoly status, at least within the United States or other specific nations. Even across regions, it was not uncommon during the evolution into the monopoly phase for an American company to buy out its main European competitors, for example. In some cases, companies were virtual monopolies, holding greater than 90% of the share of sales in a country, while in other cases it was only about 60 or 70%. In those cases, the term “dominant player” would be a better description. For some hydrocolloids and companies, the monopoly phase did not originate through growth out of a natural beginnings phase, but was obtained essentially instantly by means of acquiring patents or some other type of proprietary technology for a specific hydrocolloid. The monopoly phase began for most hydrocolloids somewhere between the 1930s and the 1960s.

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What characterized the monopoly phase of hydrocolloids were the general properties that characterize monopolies in any context. These included a number of positives and a number of negatives. The positives helped the monopoly companies not only to perpetuate for a while but also to grow sales substantially and reap huge profits yearly for a time. The negatives led to their eventual undoing as monopolies because market forces eventually stormed through to correct market imbalances. One of positives of the monopoly phase was the growth in the use and applications of each hydrocolloid. The monopoly companies were making excellent profits by selling their hydrocolloids. They had potential for more sales and more lucrative profits if they promoted their products. Because of the high profits, they had a lot of money to spend on advertising, on large sales forces, on large applications development labs, and on technical service staff. All of these were used to promote the growth of the various hydrocolloids and to give each an important niche in the food industry. The food industry customers benefited because they were better able to solve problems with their foods, especially stability and textural issues that had previously vexed them. Food industry customers also began to learn more about hydrocolloids in ways that would help them in future product development projects. New product development started to include the consideration of specific hydrocolloids right from the start. In fact, some new product development efforts and concepts were based on the stability and structural features that only hydrocolloids could provide. The monopoly supplier provided general training and specific application guidance in the form of prototype formulations. So hydrocolloids started to become mainstreamed in the United States. Instead of only looking at the all-American modified starch as the primary thickener and gelling agent, product developers began to look at carrageenans for custards, alginates for pie fillings, agar for icings, etc. European product developers had always been more aware of hydrocolloids and less dependent on starch. This is partly due to the fact that hydrocolloids were more a part of the history of various countries and also due to the fact that corn and cornstarch was not native to Europe. Also, during the monopoly phase, American product development scientists began to be exposed to more options due to the promotions of the major hydrocolloid companies. Another possible benefit during the monopoly phase, although it was a two-edged sword, was the development of standardized-type grades.

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If only one company is the major supplier for a hydrocolloid, it has at its disposal the ability to unilaterally set up grades for that type of hydrocolloid. Although this ability could have been and was misused somewhat, as will be explained later, it was a positive in that it allowed hydrocolloid users to begin to understand how specific hydrocolloids could be classified and to gain some knowledge of what grade would make sense on the basis of the application being worked on. Thus, the concepts of viscosity, gel strength, mesh size, and various stabilities to pH, salts, proteins, heat, etc. were elucidated into specific grades for each hydrocolloid. Prices were very, very high during the monopoly era; and for hydrocolloids buyers looking for value, the monopoly era was a difficult time. For one thing there was the general acceptance of the notion that the making of the primary hydrocolloids is some sort of a combination of art and highly specialized, extremely proprietary scientific knowledge. Because of this, hydrocolloids themselves were thought to be very idiosyncratic entities that are hard to duplicate from one manufacturer to the next. This deception was a means by which the monopoly companies maintained their status long beyond what logically would have been expected by market conditions. They were facilitated in keeping their monopoly status by a number of other factors. For one thing most food product developers had not learned their rudimentary knowledge of hydrocolloids during their college studies because food science departments in those days were notoriously weak in the understanding and teaching of hydrocolloids. They also placed little emphasis on hydrocolloids. For example, a whole course might be devoted to carbohydrates or to making ice cream, and in each case only 1 day might be spent on all the hydrocolloids. Thus, the monopoly companies taught the food industry most of what it knew about hydrocolloids. Therefore, the food industry had a loyalty to the monopoly companies as teachers, very well compensated teachers, and had trepidation about graduating from their schools. It was not only the general knowledge of hydrocolloids that they learned from them, but they also gained prototype formulations that would be useful to make quick progress on new projects. Also, they were accustomed to the grades of the monopoly company and even sometimes knew which one to request. On the topic of grades, the monopoly suppliers often tried to obfuscate the grades to make them more difficult to match by competitors.

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Among the most notorious tricks in the category was the trick of leaving the most crucial specification completely off the specification! Perhaps the most common example of that was to have a ␬-carrageenan specification that did not have a gel strength specification even though it was primarily used to provide gel properties to food. Some carrageenan manufacturers continue this practice to this day but most do not omit the crucial property from specifications any longer. Another means of making grades difficult for competitors to match was the use of complicated blends containing a number of gums and other ingredients. In truth, many of these applications could have been served by a simple hydrocolloid or a much simpler blend, but the monopoly companies used their positions to promote the more complicated alternatives.

The Semicompetitive Era of Hydrocolloid History Eventually, by the 1980s for some hydrocolloids and into the 1990s for other products, the semicompetitive era finally dawned. The enormous profit margins of the monopolies was finally seriously challenged and overcome in the United States mostly by highly established companies from other regions of the world. Most of these companies were European, but there were a few important ones from South America and Asia as well. This era is termed the semicompetitive era because the companies penetrating into the marketplace at this time were also interested in maintaining nice profit margins. They were simply willing to be less exorbitant than the monopolies to get some penetration into the large U.S. marketplace. At first, the primarily European companies that precipitated the semicompetitive era made slow headway in displacing the monopoly companies at U.S. food accounts. Many purchasing agents considered it a bold move, even a reckless move, to replace the incumbent supplier in many U.S. food companies, even for substantial savings. There were also some costs involved in switching, primarily the costs of testing a new supplier’s product. These testing costs were often much higher than necessary because of a near absurd worry that another company’s product might not work in even simple food products requiring straightforward hydrocolloid functionality.

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The semicompetitive era was firmly established eventually because the primarily European companies that brought it about took the following actions. They convinced the food companies in the United States that they could be trusted because they also had decades of experience in making and selling the hydrocolloids. They made it clear that they could provide high quality technical support, including applications assistance. Food applications in Europe are somewhat different, but not too different, so this worked acceptably and improved with time. The European companies also established U.S. offices or subsidiaries, stocked their product in U.S. warehouses, and hired American employees to work in sales, technical service (helping to improve applications support for American applications), and customer service. All of these factors helped them gain some market share. They also offered substantial savings from the bloated prices that were found in the marketplace at the time. One last thing the companies that penetrated the U.S. market did during the semicompetitive era was to offer exact match products to the monopoly companies’ products. This was absolutely essential. Some of the products being sold by the monopoly companies were technically logical grades; some were strange concoctions that were created because of how difficult they would be to match. In any case, to succeed in those days in replacing the incumbent, an exact match from a functional and specification point of view was generally essential, and the new players were qualified to do this. Their long experience in making these hydrocolloids enabled them to know how to exactly match the incumbents’ monopoly grades. The providing of great match products was initially a source of some astonishment to the food companies because it shattered the great myth that hydrocolloids were some magical entities that only one or two companies knew how to make correctly for each kind of hydrocolloid. Not only did the psychological and sociological significance of this myth being shattered fully deliver the hydrocolloid community in the United States into the semicompetitive era, but also it augured the very soon to follow competitive era and the now dawning commodity era. For the hydrocolloid user, the semicompetitive era ushered in more benefits than simply notably better prices. For one thing, more beneficial hydrocolloid grades were now available and promoted. In the monopoly days, the monopoly company decided for which grades it would conveniently be able to get raw materials, and then promoted

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those grades. With new companies now part of the picture, more grades became readily available that were more suitable for specific applications than those which had previously been utilized. Thus, for example, high “G” (guluronic acid) alginates became more available and used where the higher gel strength was beneficial. When hydrocolloid users saw the benefits of using some of the newly promoted grades of the newer players in the marketplace, it helped put another nail into the coffin of the exclusive one company hydrocolloid supplier philosophy. Users of hydrocolloids realized that having several companies competing against each other brought out more efforts to provide specialized solutions for customers’ individual needs. For the high G alginate example, it wasn’t that high G alginate had been unavailable previously; it was that when three or four companies were suddenly competing, each was anxious to promote something they felt the others were underweighting. Also, the various raw material supplies of each manufacturer varied somewhat, and this allowed each to specialize in specific product grades. During the semicompetitive era, whole new categories of products suddenly became available. An example of this is semirefined carrageenan, a less processed carrageenan that is cheaper to make and therefore cheaper to buy. It still has good functionality and is now the cost effective choice in many food applications.

The Competitive Era of Hydrocolloid History The competitive era began for some hydrocolloids, notably xanthan gum, before the dawn of the new millennia, and for some other hydrocolloids it began during the first decade of the twenty-first century. It was really the natural outgrowth of two factors. One was the continuation of the thinking and practices that led to the semicompetitive era, that is a willingness to test new suppliers and to try to get the best value in hydrocolloid purchases. The second factor was the amazing growth of Asia, especially China, as a world economic colossus. Before China became a major supplier of hydrocolloids in the American and European markets, it had already become a major manufacturer of electronics, specialty chemicals, and just about everything else. It was to be expected that at some point it would turn a major focus on food hydrocolloids.

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This was helped by the fact that beginning in the 1990s, and in some cases earlier, European and American hydrocolloid companies went to China and tried to set up manufacturing arrangements and partnerships there as a means to gain a source for less expensive hydrocolloids to sell. They were trying to gain an advantage over each other and also hoped to develop and penetrate a Chinese hydrocolloid users market, which was still in its infancy. Although many of these early partnerships ended and some of the entities in China went bankrupt, the technology had rapidly spread in China and many new plants arose. Already in the 1990s, quite a lot of Chinese hydrocolloids were being bagged into the premium labeled product bags of the major western companies and sold throughout the world. For a time this amounted to rising profits for the established western companies since they were selling the products at established prices but were paying much less for the products made in China than it cost them to make the same products in their old American and European facilities. Eventually, however, the Chinese companies and various western distributors also started selling these Chinese products, but at the much lower prices now possible due to the low manufacturing costs. The competitive era was now seriously underway. The competitive era was characterized by intensive price competition among the hydrocolloid suppliers. Instead of looking at how much profit could be extracted from buyers, the thinking was more at what margin above costs could the products be sold and still be able to stay in business, and then how can costs be lowered? In the competitive era, three groups competed against each other in the American marketplace for hydrocolloid sales. The first group was the manufacturing companies that competed during the semicompetitive era, including the original monopoly companies and the competitors that arose during the semicompetitive era. The companies in this group were now trying to drastically reduce costs, especially the number of employees, to close old and expensive American and European plants, to buy more products in China, sometimes to buy whole Chinese plants, and generally to make a transition from being primarily a manufacturer to being largely a distributor. Even if they owned Chinese plants, it was still more of a reseller role than owning plants in their native countries. The second group was the Chinese companies selling products themselves directly to American customers. This generally only worked for

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major American users of hydrocolloids, such as blenders and some large food companies, since many Chinese manufacturers expected companies to buy whole containers and not to expect much technical help. The third group either had comanufacturing or partnership arrangements in China and elsewhere or bought from China in some way and then acted as wholesalers, blenders, or distributors in the United States. This was the growing group among the three listed because they were not saddled with old plants and antiquated operations based on earlier eras of the first group and all the logistical, cultural, and technical support problems of the second group. The best companies among the third group provided top notch technical service and applications support, US–based warehousing and dedicated customer service, guaranteed quality products, and excellent prices based on low overheads.

The Commodity Era of Hydrocolloid History The final era of hydrocolloid history is the commodity era. Most of what is needed for this era is already coming into place. First, it has now been established that hydrocolloids of equal quality can be made in the United States, Europe, and Asia. That is not meant to imply that all manufactured hydrocolloids are of equal quality, but excellent and equivalent quality hydrocolloids are made in a number of totally different plants operated by completely separate companies. The second thing is that specifications can, when properly instituted, specify exactly what properties are important. As has been stated earlier, many American and European companies have been in the habit of using Chinese hydrocolloids instead of their own produced hydrocolloids and selling these to their customers. This is an implicit way of admitting in a practical way that their products have become commodities. What is a commodity? Something that can be sold based on specifically measurable properties. Hydrocolloids, all of them, fit this description. Some are somewhat easier than others to sell this way because the properties are simpler to understand and simpler to measure accurately. All of them can be measured acceptably and sold as commodities. What stops them from being sold as commodities now? The major western companies want to be able to sell their products at as much of a

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premium as possible, even in the competitive era, and hence would not like to see their product area commoditized. The Chinese companies for the most part would benefit from hydrocolloids being commodities. This would increase the direct and indirect sales they could make to the United States and Europe and other parts of the world. The third group, comanufacturers, distributors, blenders, etc. might have mixed feelings. On the one hand, they currently provide a service to their customers by providing some type of screening service for their customers. On the other hand, they know that commoditization would make it easier to go after the old-line manufacturers’ accounts, and they know they could undercut the still-bloated overhead of those companies and offer lower prices for the same product. For many agricultural products, the U.S. government provides standardization information to allow commodity trading. This benefits farmers, processors, users, and traders of these commodities. For hydrocolloids, an independent agency will be needed and most likely will arise to set specifications for grades. They will make a lot of money doing this because customers will then require that suppliers must be certified by this agency to be able to trade that hydrocolloid commodity grade. As of the writing of this book, this is still in the future; but it is likely to happen. And once it happens for one hydrocolloid, such as xanthan gum, it will quickly happen to nearly all hydrocolloids. With ISO and GMP type certifications now standard for all hydrocolloids manufacturers throughout the world, the only step still needed is to set up specific grades and have certification to prove that grade can be made in the facility. But even though the “official commodity status” of most hydrocolloids has not yet been established, as we go further into the competitive era more aspects of the commodity era manifest themselves. Among these are a greater reliance on specifications than ever before and a greater desire to make sure specifications truly reflect important functional properties. Finally, a greater insistence on getting the best possible prices by allowing intensive bidding by all qualified sellers is coming to the fore. Guar gum and gum arabic are already being sold as commodities. They are listed by specific grades, along with the latest weekly price, alongside other commodity products in marketing publications. One by one, the other hydrocolloids, are sure to follow this trend.

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Applying Hydrocolloid History to the First Purchasing Key In light of hydrocolloid history, what wisdom can be applied to the first purchasing key, product grade selection? By selecting a product, which only one supplier can putatively make and which the customer does not understand at all, the customer would be putting himself back into the monopoly era. By selecting hydrocolloids that many suppliers offer and a customer understands somewhat, the customer puts himself into the competitive era, allowing many suppliers to compete for the customer’s business with both price and services. By fully understanding a product and knowing all the suppliers who offer both top quality and best pricing, the customer is in the most favorable position and begins to enter the commodity phase. If the customer already is using a highly specialized hydrocolloid or blend, the best advice is to allow other suppliers to have the opportunity to match that product. It again allows at least some other supplier to compete for the business. Also, as a general principle, it is best for a product development group at a food company to begin projects with the plan to find at least two or more suppliers who can provide a hydrocolloid that will work well in the application being developed.

The Importance of Correct Product Selection The first nine chapters of this book focused on educating the hydrocolloid user about the use of hydrocolloids in foods. In nearly all cases, the specific hydrocolloid types needed for various food products were delineated, along with recommended use levels and sometimes even details about grades. Of course, in many cases, a number of grades would work well in a given application and it would be counterproductive to make it seem that only one exact grade would provide the needed functionality. It is important to understand how hydrocolloids are divided into specific grades. Two opposite problem groups concerning grades are often detected in hydrocolloid users and purchasers. One group of users and purchasers thinks hydrocolloid grades are very complicated to understand and often therefore just latches onto one grade that works adequately in all of their food products and purchases it from one or two suppliers. From a technical point of view, optimum functionality

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is usually sacrificed by this approach. Purchasing, almost by definition in these cases, fails to achieve good pricing because lack of knowledge leads to lack of confidence, which leads to overly cautious and expensive purchasing decisions. It is difficult to advance much past the semicompetitive era in these cases, and on rare occasions a customer still resides in the monopoly era, having only one approved supplier! The opposite problem group thinks it understands grades well and thinks it knows exactly what grade it wants to purchase. However, this group only understands part of what is involved with grade, such as viscosity or gel strength, and doesn’t fully understand all the other nuances that go into determining and specifying hydrocolloids grades. For example, it may not fully understand that some hydrocolloids can be sold as pure hydrocolloids, hydrocolloids with small amounts of other added ingredients, or even mostly added ingredients with small amounts of hydrocolloids. Viscosity or gel strength alone will not specify which of these three options a customer is purchasing. From a technical point of view, ideal functionality again may not be achieved, and from a purchasing point of view an accurate and direct comparison of various suppliers’ products may not be occurring.

The Basis of Grades: Hydrocolloid Functionality Hydrocolloids are generally used in foods to impart or contribute to structure and texture, which often has an important added benefit of providing stability. Stability can be thought of as preserving a desired structure or texture. Structure and texture include thickened or semigelled liquids such as salad dressings or smoothie beverages, gelled products such as water dessert gels, and even suspension of particles such as in chocolate milk. Hydrocolloids function in this manner due to their innate abilities to structure water, sometimes also interacting with other key components of the food, especially cations and proteins. Hydrocolloids are generally very large molecules that can restrict and trap water to form highly viscous solutions or true gels. The basis of determining and differentiating grades for hydrocolloids is therefore based on two parameters. The first is the exact chemical structure and nature of the specific hydrocolloid. The second parameter is the change this specific hydrocolloid causes in foods.

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It can quickly be surmised that these two parameters are only two sides of the same coin. For the exact chemical structure fully determines the exact effect the hydrocolloid will have in a specific food. Nevertheless, it is helpful to think in terms of two parameters when it comes to hydrocolloid grades. For a number of reasons, historical and technical, the sum of properties that are used to determine an exact grade are an amalgam of chemical properties combined with the effect the gum has on foods.

A Review of the Key Items Used to Differentiate Grades The following list reviews the key items that are used to specify grades for hydrocolloids. For each item there is a brief discussion of how this item impacts individual hydrocolloid types. Chemical Structure Although it is true that all aspects of hydrocolloid functionality are due to the chemical structure, some major divisions of grades are based directly on chemical structure. It goes without saying that xanthan gum is xanthan gum and not guar gum because of the type and arrangement of the sugar molecules that compose its hydrocolloid polymer. However, within the same hydrocolloid type, say sodium alginate, there are enough differences in the ratio, if not the actual type, of sugar molecules that compose the alginate polymer to account for significant differences in functionality. Significant differences of functionality are a good basis for grade differentiation. Thus, for sodium alginate, a linear polymer composed of two sugar acids, mannuronic acid (M) and guluronic acid (G), the M/G ratio is one determining factor for grades for this gum. Generally, three M/G ratio grades are marketed by alginate manufacturers. In the case of alginate, the varying M/G ratios are due to naturally occurring differences in M/G ratio found in the brown seaweed species that are rich in alginate. Similarly, the various red seaweed species that are rich in carrageenan vary in the type of carrageenan that can be extracted from each. Not all chemical structure differences are due to differences found in the raw materials. There are also intentional chemical modifications

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Table 10.1. Selected hydrocolloid chemical structure differences. Hydrocolloid Subtype

Basis

Property

Carrageenan

Kappa Iota Lambda

Seaweed species Seaweed species Seaweed species

Hard, brittle gel Soft, elastic gel Viscous solution

Alginate

High G, Low M Medium high M High M, Low G PGA High methoxy

Seaweed species Seaweed species Seaweed species Chemical modification Processing

Pectin

Low methoxy Amidated

Hard, brittle gel Medium gel Pseudo gel No gel, emulsifier Gels with high sugar and acid Processing Gels with calcium Chemical modification Gels are thermoreversible

carried out during manufacturing to create modified polymers for functional reasons. Two examples of these are propylene glycol alginate (PGA) and amidated pectin. Table 10.1 lists some major hydrocolloids and the naturally occurring or chemically synthesized changes that are used for grade divisions. Viscosity For many hydrocolloids, viscosity is the key item considered in terms of grading. This is true for xanthan gum, guar gum, locust bean gum, konjac, and others. For a number of other gums including CMC, sodium alginate, and PGA, viscosity is a key grade differentiator but not the only one. Viscosity, technically the resistance to flow for a liquid, is an indicator of how thick the hydrocolloid makes water or some food product. Viscosity is normally expressed in a unit called a centipoise (cP) and is generally measured as the “apparent viscosity” by commercially used viscometers. Although viscosity is usually measured by dissolving the hydrocolloid in water, it is reflective of how the hydrocolloid would function in a more complex food system. Whether the viscosity is higher or lower for a specific hydrocolloid is generally based on the average molecular weight of the hydrocolloid. The higher the average molecular weight, the higher the viscosity. Thus

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the chemical structure, the average polymer length, is the basis for differences in viscosity. However, it is much easier for the supplier and much more meaningful for the customer to report the viscosity of the hydrocolloid, and therefore viscosity is used for grading and not molecular weight. The following is a list of some pertinent facts related to viscosity: r Lower viscosity grades can be made by suppliers from naturally higher

viscosity raw materials by increasing the severity of processing.

r Viscosity test methods must be very carefully compared to ensure

r r

r

r

that suppliers and customers get the same viscosity test result for the same samples. Especially important is exactly how the hydrocolloid solution is mixed just prior to testing for viscosity. Most of the time, a solution is mixed just prior to measuring the viscosity. Viscosity is very nonlinear and doubling the level of hydrocolloid may, for example, cause a 10-fold increase in viscosity. If a high amount of thickness is desired in foods, it is often a better bang for the buck to use a high viscosity grade at a lower user level than a lower viscosity grade at a higher use level. Viscosity can be a useful comparison tool for hydrocolloids of the same type, but different hydrocolloids with the same viscosity may have quite different textural properties that will influence desirability in a specific food. Viscosity ranges should not be too wide, such as 450– 700 cP. It is best to not have a range of more than 100–150 cP, such as 550–700 cP or even 600–700 cP.

Table 10.2 gives typical ranges for viscosity of a number of gums at 1% solution level. Table 10.3 gives the viscosity of a number of hydrocolloids at 4 different concentrations from 0.25 to 1.00%. Gel Properties Besides viscosity, gel properties are the other key attribute of hydrocolloids. Gel properties, to put it most simply, are a composite of the nature of the gel and the strength of the gel produced. The nature of the gel includes such parameters as brittle versus elastic and whether the gel is self healing, that is when it is punctured can it reform somewhat. Gel strength is also a composite of several measurable properties,

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Table 10.2. Typical viscosity ranges of hydrocolloids. Hydrocolloid

Typical Viscosity Range, 1% Solution (cP)

Sodium alginate Xanthan gum Guar gum Locust bean gum Carboxymethylcellulose (CMC) Konjac

1–950 (higher with added calcium) 1,200–1,800 (most prevalent grade) 2,000–6,000 (low MW types also available) 1,500–3,000 1–6,000 2,000–36,000

but the most often cited of these is the amount of force in g/cm2 required to puncture the gel with a probe. Carrageenan, agar, pectin, alginate, and gellan gum are the most utilized gelling hydrocolloids, though some of these are also used in nongel applications. Grades of these gums are at least partially based on the gel strength they produce in water. In the case of carrageenan, sometimes milk gel strength readings are used to establish grades. As with viscosity, for a given specific type of hydrocolloid, such as kappa-carrageenan, it is often most cost effective to get the maximum gel strength grade because then it can be used at a lower use level. A price comparison versus use level comparison for grades can be useful if suppliers price lower gel strength grades much lower than higher gel strength grades. Also, as with viscosity, the exact procedure and instruments used to measure gel strength and other gel properties must be carefully coordinated between supplier and customer to ensure that each gets the same measurement for a given sample. The measurement of gel strength

Table 10.3. Viscosity at different concentrations in water viscosity (cP). Hydrocolloid Konjac Guar gum Carboxymethylcellulose (CMC) Sodium alginate

0.2%

0.4%

0.6%

0.8%

1.0%

89 36 69 23

1,350 268 194 54

6,744 812 506 123

20,046 1,834 1,992 309

36,093 4,549 2,631 642

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is only an approximation of the gelling functionality provided by the hydrocolloid in a specific food system. Fortunately, the gel strength test is often quite useful in predicting whether the gum will work well in the food. Thus, if a new supplier is found and its gum has the same gel strength as the previous supplier, most of the time the product will work as well in the food as the previous supplier’s product. One caution would be not to have one-way gel strength measurements, such as greater than 1200 g/cm2 . There should always be both an upper and lower level in a specification, such as 1200–1400 g/cm2 . Mesh Size of Particles A significant parameter used to differentiate between grades of hydrocolloids is mesh size. This is so because the way hydrocolloids can be incorporated into foods is dependent on the particle size of the hydrocolloids. In general a coarse particle size hydrocolloid requires more time to hydrate but is less prone to lumping problems. A fine particle size particle requires less time to hydrate but must be either mixed with more agitation or must be thoroughly mixed with other solids before adding to water or other liquid. Coarse mesh hydrocolloids can be as coarse as 40 mesh, while typical fairly coarse hydrocolloid mesh sizes are 60 and 80. Mesh sizes of 120, 150, and 200 are in the fine mesh range, and occasionally a 325 mesh grade is utilized. For finer mesh size particles, dusting becomes a concern when adding the hydrocolloid to foods during processing. From a grading and quality assurance (QA) point of view, one concern with mesh size is the use of one-way grades and/or insufficiently defined grades. For example, a typical poorly defined grade might say that the hydrocolloid in question must have 95% of the particles finer than 80 mesh. Of course it is not known in this case what the 5% might be, since it could be 40 or 60 mesh. A bigger concern is that the 95% could all be 85 mesh or it could be mostly 150 mesh. The grade doesn’t specify, and therefore each supplier might make it differently and still be within the stated specifications. To avoid problems when switching from one supplier to another or even to ensure that problems don’t develop in the future with the same supplier, it is best to do a complete mesh profile using several mesh screens. Then a new supplier can be told that 5% should be no coarser

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than 60 mesh but less than 80 mesh, 50% should be finer than 80 mesh but less than 120 mesh, etc. Currently, CMC grades are good models of how this can be done and this methodology can be incorporated into grades for other hydrocolloid types. Organoleptic and Appearance Properties In some cases, hydrocolloid companies will establish lines of products for a specific gum on the basis of greater purity, cleaner flavor, whiter color of the powder, and more transparent appearance in water. To make products of this type generally involves more expensive processing for the supplier, but can be an important benefit to the customer in foods that have very sensitive color, flavor, and appearance criteria. These might include very delicately flavored foods or foods that require a transparent appearance such as certain beverages. Grades in these cases would be differentiated from more typical grades where a customer would not need these special properties. Special Stabilities Although hydrocolloids are sought for their ability to stabilize foods, they themselves are also subject to stability considerations. For example, xanthan gum is stable to below pH 3.0 but guar gum is generally not as stable in this pH range. However, guar gum can be made more stable to this low pH environment. Manufacturers who make this type of guar gum would therefore promote this product as a low pH stable guar gum grade. Another example of this would be xanthan gum which is stable under high salt conditions. Blends A final major criterion for establishing grades for hydrocolloids has to do with blending hydrocolloids with other hydrocolloids and/or other components, such as ions that establish or increase the functionality of hydrocolloids. Since this is a major area for grade differentiation and since this involves a multitude of options for the supplier and customer, it is best to devote the next section of this chapter to reviewing this topic in detail. We will entitle this type of grade differentiation as product categories because within these categories there are a number

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of grades available for each hydrocolloid based on the other six criteria of viscosity, gel strength, etc.

Product Selection: The Three Levels of Hydrocolloid Classification There are three levels of classification for hydrocolloids, all of which must be understood to select the correct product for a specific food application. The first is the hydrocolloid type. Xanthan gum, carrageenan, and pectin are types of hydrocolloids. Suggestions for use of the various hydrocolloid types in foods are found throughout this book. The second level of classification is the hydrocolloid category. There are basically four different categories of marketed as hydrocolloid products. These are pure hydrocolloids, functional blends, synergistic blends, and application blends. The third level of classification is the hydrocolloid grade. Grades refer to functional attributes such as specific chemical composition, viscosity, gel strength, mesh size, and sometimes to more specialized stabilities. These attributes have just been reviewed. The focus will now turn to hydrocolloid categories to finish our discussion of product selection. Table 10.4 summarizes the four types of product categories.

Hydrocolloid Product Categories Pure Hydrocolloid The first type of hydrocolloid product is the pure product. Most of the hydrocolloids sold can be bought as pure products, and for some that is Table 10.4. Hydrocolloid categories. Category

Hydrocolloids

Other Ingredients

Pure hydrocolloid Functional blend Synergistic blend Application blend

One One Two or three Two or more

No Ions/fillers No Ions/fillers/others

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the predominant form that is sold to food customers. The pure product is 98–100% hydrocolloid. For labeling purposes, only the hydrocolloid name is listed, such as carrageenan. The advantages of buying pure hydrocolloids are many. Firstly, it makes pricing of the hydrocolloid and comparisons to other suppliers of that pure hydrocolloid very straightforward. It is not necessary to calculate how much actual hydrocolloid is being bought as a percentage of the total weight of what is in the bags. Secondly, it is generally possible to find more purveyors of pure hydrocolloids than sellers of any specific nonpure products, since the latter differ somewhat from supplier to supplier. This can also assist with getting the best pricing. Thirdly, quality assurance is more straightforward for pure products since the QA tests are giving the results only of the pure hydrocolloid and not of the sum total of a number of components. Fourthly, shipping, warehousing, and manufacturing costs are minimized since space is not being devoted to fillers. Fifthly, the food labels are cleaner since multiple components are not required to be listed. Functional Hydrocolloid Blend The second type of hydrocolloid product consists of a single hydrocolloid with some added nonhydrocolloid component or components. Theoretically, the nonhydrocolloid components are combined with the hydrocolloid to promote, increase, or maximize some important functionality of the hydrocolloid. The use of additives cause the functional hydrocolloid to be a diluted hydrocolloid; that is, it is not pure gum. In some cases, the diluting ingredients comprise only 10–15% of the blend weight, but in other cases the hydrocolloid is only 15% of the weight and the rest is diluents. The bulk of additives used to dilute the hydrocolloid can be assigned to three categories. The first of these categories includes ions that are necessary for gelation of certain gelling hydrocolloids. The most wellknown of these gelling hydrocolloids and the ions required are calcium for alginate, pectin, and ␫-carrageenan and potassium for ␬-carrageenan. To provide the necessary ions, potassium chloride is blended with ␬-carrageenan, and various calcium salts are blended with alginate, pectin, and ␫-carrageenan. The second category includes additives that are added to allow the hydrocolloid to dissolve in food products where other components present

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in those food products would hinder the hydrocolloid from dissolving. The prototypical example of this type is the use of phosphate sequesterants used to temporarily bind calcium present in a food product to allow sodium alginate to dissolve. Gellan gum is another gum which has sequesterants added to allow it to dissolve. The third category of additives includes various sugars such as sucrose or glucose that are blended with a hydrocolloid. These inert ingredients also help a hydrocolloid dissolve, especially under low shear. The dry particles of the hydrocolloid are separated from one another by the sucrose or other inert ingredients, and this helps prevent lumping of the hydrocolloid under low shear conditions. Sometimes functional blends are euphemistically called “standardized” by the suppliers. The rationale is that for a product, carrageenan being a typical example, the gel strength may vary somewhat from batch to batch produced at the plant. Although, it is possible to blend batches of carrageenan to get the right gel strength, another way to do this is to use more or less of a diluting ingredient. Also, the diluting ingredient can be something that is useful for gel strength. For example, ␬-carrageenan is gelled by potassium ions. So using a diluting ingredient such as potassium chloride allows the carrageenan to achieve the maximum gel strength. However, more potassium chloride may be used than is needed to achieve maximum gel strength. So, in the end, the dilution is also used to allow a cheaper per pound hydrocolloid. This diluted product will be lower in functionality than a pure product to which sufficient potassium is added for maximum gel strength. From a product development point of view, the food scientist should know what the lowest and highest level of actual hydrocolloid is that is used in the diluted product. Ideally, these lowest and highest levels should be tested in the food product to ensure that within this range there is no difference in the food product made with the hydrocolloid. The product developer must ascertain from the hydrocolloid supplier what level of ion is required for that hydrocolloid for maximum gel strength. Calculations must then be done to determine how much of this ion is present within all the ingredients used to make the food product. Then a determination can be made of how much extra of that ion is needed and how much is provided by the diluting ingredient added to the hydrocolloid. In this way, the product developer can ascertain how much of the potassium added to carrageenan is actually needed for the food product and how much is superfluous.

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It is acceptable to add a little more ions than is necessary to allow some margin in case some of the ions are bound up for some reason. For example, 7.2% of calcium is required to stoichiometrically react with sodium alginate to make calcium alginate, the major gelled form of alginate produced in foods. However, 10% of calcium based on alginate weight may be utilized to allow some safety margin. What is important to a customer is that the supplier explains to him in detail exactly what kind and what percentage of ions are required for the specific hydrocolloid to gain maximum functionality. Then and only then can the customer determine among various diluted and pure hydrocolloids what category fits most closely to the customer needs. From the purchasing point of view, the minimum level of hydrocolloid needs to be known so that the pricing can be compared to other suppliers. It is especially critical not to compare prices of pure hydrocolloids with diluted hydrocolloids. If the customer likes a supplier who primarily sells pure hydrocolloids at a good price, it would be shrewd to ask that supplier if they could supply a match product for a required diluted hydrocolloid and what the price of that would be. That could turn out to be the best option for that customer. Relevant QA testing for functional blends can be difficult in that there can be different combinations of ingredients that can give the same QA test results but be quite different in food functionality. Thus, the product development scientist must ascertain the functionality of this product in tests of the food product itself. A functional blend can be very helpful for customers to make food products with less added ingredients, and without having to figure out the right proportions of sequesterants and calcium, in the case of alginate. The downside is that the blend being used is at best an approximation of what would be ideal for each individual food. If a product development scientist would take the time and energy to learn how to formulate a hydrocolloid with its functional accoutrements, then each food product could be more tailor-designed to be ideal, both for processing ease and final product appeal and stability. From a pricing point of view, the functional blends can be very profitable for suppliers and very expensive for customers on a price per hydrocolloid weight basis. There are blends of this type in the marketplace where the hydrocolloid content is only 15–20% of the blend weight, and yet the price charged can be at the full price of a

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pure hydrocolloid. Needless to say the other blend components, salts and sugars mainly, are a small fraction of the cost of the hydrocolloid in the open marketplace. If the purchasing agent is required to buy this type of blend, they should try to find at least three suppliers who can make and sell an equivalent product and whether a better price can be obtained by bidding. The hydrocolloid company will have more room to move on prices of blends since the cost of the product is so much lower for them than that of pure hydrocolloids. Of course, the supplier will have blending costs and reshipment costs to bring all the blend ingredients to one place, but these will still be small compared to the hydrocolloid cost itself. Synergistic Hydrocolloid Blend The third type of hydrocolloid product, another blend, is a synergistic combination of hydrocolloids, usually not diluted. Generally these are combinations of two hydrocolloids, but blends of three are also occasionally sold. Frequent combinations of two include xanthan gum/guar gum, xanthan gum/locust bean gum, carrageenan/locust bean gum, and konjac with any number of other second gums including carrageenan and xanthan gum. Xanthan gum and guar gum at a one-to-one combination, for example, provide more total viscosity than would be expected from the additive effect of each one’s individual viscosity contribution. Most of the dual gums sold this way are truly synergistic, that is, the effect of the two is greater than what would have been expected by the sum of the two. In some cases, the gums simply provide similar functionalities, though not synergistically. Thus, in Europe, it is common to sell blends of methylcellulose and sodium alginate. Both provide good high temperature viscosity or gelation, but not synergistically or even from the same chemical mechanism. They are sold as a blend because they both help to provide a similar function, such as preventing boilover in fruit pies during heating. For the product development scientist, it really would not be difficult to buy the two gums separately and blend them in the formulation. It is not difficult to do so and would save money. And it would allow textural variability. Even though, for example, 50/50 xanthan gum and guar gum give maximum synergy, the texture of say 75/25 guar/xanthan might be superior in a given food, and the blend would be considerably

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less expensive since guar is much cheaper than xanthan. By the same token, xanthan gum is a much better suspending agent than guar gum, and so a 75/25 blend of xanthan/guar may be more appropriate for some food applications. There is one exception to the concept that it is generally easy for the customer to blend the hydrocolloids for a synergistic blend versus buying a premade blend from a supplier. This is when the synergistic combination of hydrocolloids is not a blend but a coprocessed combination of two hydrocolloids. In some cases, during the manufacturing process of a hydrocolloid, if another hydrocolloid is added during the processing a special enhanced functionality may be imparted. In those cases, the customer would not be able to duplicate this fully by blending. However, this functionality should be verified by the customer in its food product, if possible. Sometimes, claims by suppliers are exaggerated regarding the superiority of coprocessed products versus standard blends. From the purchasing agent’s point of view, it would certainly be less expensive to buy two gums separately and blend them. The only savings might be having one less item to inventory. The extra costs involved would be due to three factors. First, guar and xanthan, for example, are essentially never made in the same plant and usually not even in the same country. Thus, a major shipping project would be entailed in bringing the two ingredients to a blending facility. Apart from shipping costs, there may be customs costs to pay as well and then more customs costs when shipped to the final customer. Second, there would be costs involved in the actual blending and repackaging in new bags. Third, in the hydrocolloid world suppliers are accustomed to considering any blend, no matter how simple or hackneyed, to be a source of much higher profits, and customers have generally accommodated them in that pursuit. So to escape this fate, the purchasing agent should ascertain the level of each hydrocolloid in the synergistic blend, price each separately, and thereby determine the premium the supplier is commanding for the blend versus the individual gums. If the decision is made to still buy the blend, it may be possible to lower the costs somewhat by finding a supplier who sells both of the gums used in the blend individually, as well as blended. If that is the case, at least the supplier does not have to pay retail price for the gum he doesn’t produce himself. This can lower its costs and hence make a lower price to the customer more possible.

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Application Blend The fourth type of hydrocolloid product is a complex blend that will include two or more hydrocolloids along with salts, sucrose or other sugars, and sometimes other functional ingredients such as emulsifiers. Blends of hydrocolloids including guar gum, locust bean gum, carrageenan, and xanthan gum, are often blended with mono and diglycerides, an emulsifier, to make a stabilizer/emulsifier blend for ice cream. Most complex blends are designed for specific applications where the customer wants a complete package from the supplier. In the case of complex blends, it is generally the case that the customer does not want the complexity of trying to develop these types of blends internally. It is possible to do so, of course, but it would require some effort. Therefore, the best option is often to find several suppliers who offer similar products to gain some leverage and a better price via competition among suppliers. QA tests, even more than for most blends, do not verify the functionality of complex blends. Performance in specific foods is necessary.

Hydrocolloid Product Categories: Summary Customers buy and use hydrocolloids to solve functional issues in their food products. If the food product is simple enough or if the customer is knowledgeable enough, then one or two hydrocolloids bought separately can be the cheapest and easiest approach, especially if these are pure hydrocolloids. Functional blends take the complexity out of dealing with required gelling ions and can also help with solubilizing the gum. But this is generally a more expensive approach and it limits the customer individually tailoring ions to individual formulations. It is important to know what the percentage of actual hydrocolloid is in the blend to compare prices from supplier to supplier and to know what premium is being paid as compared to a pure hydrocolloid. Most synergistic blends are not very complicated to understand and can increase the efficiency of the gums used. Important functional properties such as viscosity and gel strength are easy to measure. It is also easy to see if the premium being paid for the blend is appreciable by comparing the price of the blend versus the price of the individual pure

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hydrocolloid components. It is not difficult to buy the individual components and add them separately. In cases where the synergy is partially based on coprocessing two gums, then the premium may be worth paying because it may not be possible to duplicate the results by adding the two hydrocolloids separately to the food product. Application blends are definitely a complex world but can simplify otherwise complicated stabilization situations for a customer. The best advice is to have two, three, or more equivalent blends that have been demonstrated to work well in the customer’s application from different suppliers. This allows some price competition among suppliers for the customer’s business and provides some safety cushion in the event that one supplier is bought out or stops producing that blend, which is not uncommon.

Product Grades: Putting It All Together Let us look at an example of a hydrocolloid and how it might be listed by grades. A food company might make a selection for a hydrocolloidtype a sodium alginate. Next the category of sodium alginate needs to be specified, and this could be a pure sodium alginate or a blend with other ingredients. For this example a pure hydrocolloid is the category selected. For specific grade, the company might select a chemical composition that is medium high M (55% M, 45% G), which would be a fairly standard type in this regard. It might select a high viscosity grade, generally 750–900 cP. Gel strength might not be listed since a high G alginate might be selected if the food product required a very strong gel. Mesh size might be either 80 or 150 mesh depending on the ease of dissolution needed in the food and the shear available to dissolve the alginate. Special stabilities probably would not be an issue for this alginate. Thus the final grade would be determined by combining the alginate type, which is the pure alginate category, medium high M chemical composition, with the viscosity and the mesh size. The grade would somehow designate all four of these properties. For example, it might be called “alginate 800–150” meaning it is pure alginate and has a viscosity of about 800 cP and a mesh size of 150. Since medium high M is the standard type, this may be omitted in the final grade designation, its absence in the grade number indicating that it is not a special M/G

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grade. On the other hand, if it was a high G product, it might be called alginate 400 G-150 meaning a viscosity of 400 cP for a high G alginate and 150 mesh size. A high M product might be designated 400 M-150. For a carrageenan functional blend example that is a blend of 80% ␬-carrageenan and 20% potassium chloride, the grade might be designated as follows: carrageenan CM 1200. The CM would refer to an application like chocolate milk and the 1200 to the gel strength. Often for carrageenans, if a food application is listed it is not a pure carrageenan. The 1200 does give us an idea of its gel strength range. What is not usually listed is the percentage of gum in the blend and the amount and types of diluents added. These have to be obtained from candid conversations with the supplier. Suppliers who add a lot of diluting ingredients generally don’t describe the types and amounts of the additives in the grade names.

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Chapter 11 Hydrocolloid Purchasing II: Pricing and Supplier Evaluation Thomas R. Laaman

In Chapter 10, hydrocolloid history was reviewed to provide the background needed to set a firm foundation for contemporary and future understanding of how a customer can apply the three purchasing keys to hydrocolloid purchasing. The first key, understanding hydrocolloid categories and grades was also reviewed in Chapter 10. This chapter reviews in detail the final two keys involved in hydrocolloid purchasing, which are pricing and supplier screening. The sum total of these two chapters is to provide a complete purchasing guide for customers of hydrocolloids. The Second Key to Purchasing Hydrocolloids: Pricing To consistently buy hydrocolloids at competitive, low prices should be the goal. This should be true for all ingredients purchased. Knowing the exact type, category, and grade of hydrocolloid is of course necessary as reviewed in the section on the first key. Screening suppliers, as described in the third key, will assist the customer in determining the final supplier group from whom the customer will decide to purchase.

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From a customer’s point of view the following list of topics, each to be addressed below, summarize the significant areas needed for understanding to obtain the best prices in this industry. These are as follows: 1. What does hydrocolloid history teach about hydrocolloid pricing? 2. The high profit mentality of most hydrocolloid suppliers 3. Customer control versus supplier control of the composite factors in hydrocolloid pricing 4. The true market price for a hydrocolloid 5. The most important factor in pricing: customer knowledge 6. Internal supplier gimmicks used to ensure high prices in the marketplace 7. Joint supplier gimmicks used to ensure high prices from their customers 8. Advantages/disadvantages for customers of spot prices, quote prices, and bid prices from suppliers 9. How customers can avoid annoying suppliers and forfeiting the best prices 10. Ways for customers to assist suppliers to gain lower prices 11. Understanding how to avoid price increases from suppliers and how to gain price decreases from them 12. The future of pricing What Does Hydrocolloid History Teach about Pricing During the beginnings era, prices were highly variable but starting with the monopoly era prices were highly controlled by the supplier and were very high. In many ways, the progression from monopoly to semicompetitive to competitive to the now dawning commodity era was driven largely by the inexorable drive of market forces to obtain true market prices. Other issues such as a desire for better or clearer grades (first key) and better supplier services (third key) were also a factors. Clearly, price was the most important driving factor in advancing hydrocolloid marketing from a supplier-centric to a customer-centric milieu. So, to begin with, history teaches us that prices during most of hydrocolloid history were not favorable for customers but were favorable for suppliers. As the next sections demonstrate, this caused a number of business principles and practices that favored high prices on the part of

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suppliers. Customers acquiesced to this high-price environment rather docilely, but in many cases the customer did not realize that other options existed, and also in some cases customers did not even realize that these prices were high by true market principles. The single most important lesson of hydrocolloid history is that the world of hydrocolloids has progressed and customers are now blessed with the opportunity to obtain consistently excellent pricing, true market pricing, indeed. However, depending on each customer’s situation, there may be layers developed over many long years that need to be unraveled and discarded to enter this currently favorable pricing world in hydrocolloids. The next sections seek to illuminate some of the issues that will be encountered. A thorough understanding of all of them will allow customers to freely pass to a mentality and then a protocol where they will obtain top quality pricing from suppliers who provide top quality products. The High Profit Mentality of Most Hydrocolloid Suppliers For most of the history of hydrocolloid use in foods, hydrocolloid suppliers were extremely successful in reaping very large profits from their loyal customers. In cases where a hydrocolloid company was a division of a larger company, they were the most profitable entities in the entire corporation and held up as models for all the other divisions on how to make huge profits year in and year out. This was the more surprising in that the food industry is generally considered a fairly lowprofit industry category compared to areas such as defense contractors and pharmaceutical companies. This idea of a high-profit mentality on the part of suppliers has been so endemic in the hydrocolloid world and is so entrenched that it is necessary for a purchasing agent to always keep this in mind when dealing with many hydrocolloid suppliers. Fortunately, for customers, this situation has been altered by a number of market correction factors that will eventually happen in any industry where profits are exorbitant and market forces are allowed to operate. Still, the purchasing agent must be cognizant of the favorable market situation that exists for customers in the twenty-first century. Otherwise the price paid will be more reminiscent of the monopoly days than the arriving commodity age. Obtaining fair pricing in this competitive era and the dawning commodity era is the goal of the shrewd purchasing agent. To achieve this,

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the purchasing manager must continue to be aware of the fact that very high profits are still the natural expectation of many hydrocolloid manufacturers and suppliers. By looking at the latest annual reports of some of the major hydrocolloid suppliers, it is clear that the high-profit objectives continue to be sustained. Therefore many purchasing agents in the United States and elsewhere are not achieving the best prices, and at least some suppliers are continuing to extract quite high profits. Customer Control versus Supplier Control of the Composite Factors in Hydrocolloid Pricing The price a customer pays for a hydrocolloid is a composite of many factors. A supplier would explain the composite price in terms of the supplier’s raw material costs, manufacturing, shipping, business operations, etc. The supplier’s profit target is also a big and generally unspoken part of the supplier’s equation. From a customer’s point of view, it is better to think of the composite pricing to be composed of factors controlled by both the supplier and the customer, and if done correctly, mostly controlled by the customer. The customer mostly controls pricing because, firstly, the customer can choose a supplier who has low overall manufacturing costs and business operations. Secondly, the customer can choose a supplier who is content with a more modest-profit target than average in this highprofit-oriented industry. Finally, the customer controls how much technical service and logistical support a supplier must provide and the payment terms the customer will accept. Long payment terms increase the supplier’s costs considerably. A supplier already has significant cash flow issues and the rates it pays to borrow cash are usually higher than for the customer. These all impact the supplier’s costs for the customer. To summarize, the customer can choose a supplier who has minimized unnecessary costs and the customer can also elect to assist the supplier in minimizing other customer-specific costs. This allows a willing supplier to charge even less for the product. Most shrewd purchasing agents understand that the customer controls pricing and make sure that they set up all the factors in their favor. One supplier may indeed experience rising manufacturing costs, but in another part of the world manufacturing costs may be declining or staying level. This is why it is wise to have suppliers who produce in different parts of the world. Raw material costs may go up all over

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the world at times, but some suppliers are shrewder at planning ahead and stocking larger supplies in anticipation of these raw material price fluctuations. So although the customer cannot dictate most of how a supplier runs its operation, the customer can choose suppliers who are adept at saving money and also can choose multiple suppliers who manufacture in diverse locations. The True Market Price for a Hydrocolloid Although it is not appropriate in this setting to enter into a sophisticated economics discussion about how to calculate a true market price for a product that is manufactured and sold to a customer, this topic should at least be touched upon briefly, especially since the history of hydrocolloid marketing clearly demonstrates that standard pricing for hydrocolloids during the monopoly and semicompetitive eras were clearly far above true market prices by any definition. Any determination of true market pricing should take into consideration all the costs associated with manufacturing and shipping a product, including raw materials, energy, etc. On the top of this should be some profit margin that will encourage the requisite capital to flow into this industry to finance establishment of supplier companies. The capital invested must allow a return greater than simply passively investing the money or investing in a more lucrative industry. Of course risk is a major consideration. Investing in a potentially more lucrative industry, such as pharmaceuticals, could return more profits if the company develops a top-selling new drug. The company could, however, go bankrupt if its research and development (R&D) is not sufficiently innovative to compete against other firms. Hydrocolloids would rank as a relatively low-risk industry, and hence the returns expected would tend to be modest. It is a low-risk industry because hydrocolloids are generally a mature industry, their use is well established across many diverse applications, and the likelihood of future use is quite secure. Of course, certain individual hydrocolloids may be less secure mainly because there may be lower cost hydrocolloids that will eventually get more market share or because of other factors. It would not be prudent to give a percentage return that would be acceptable in this industry. For one thing, that would be highly dependent on the inflation rate of the currency used to calculate the profit. A better way to establish a reasonable market price is to let market forces dictate

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this price. Barring monopoly conditions or semicompetitive market conditions, the marketplace is very effective in revealing a true market price for hydrocolloids. Thus, the true market price would be the lowest price for any specific quality and grade that is available in the marketplace, excluding such prices as inventory clearance from a bankrupt firm, etc. Why is the lowest price the true market price? Because business is a competitive enterprise and in each business situation, the shrewdest players are the most successful in managing all factors to obtain the best price possible for its customers for a specific market-determined grade of product. These shrewd players demonstrate on a practical basis how this type of business can be operated most efficiently, and their prices therefore become the de facto market prices. For any supplier who charges a higher price, a careful business evaluation could be conducted to find the source of the higher price, whether it be higher manufacturing costs, less efficient logistical operations, bloated staffing, or expensive business office pricing. On the last point, there are hydrocolloid companies who actually have their marketing and sales headquarters in large and expensive office buildings in major cities! No raw materials, manufacturing locations, or customers are in these cities. The locations are there as part of an outdated corporate philosophy that no longer has any validity in this more competitive era. Supply and demand fluctuations can impact the prices temporarily, but even then the lowest prices would indicate the true market prices during those specialized situations. Many companies try to sell at prices higher than the true market price. If it is due to a desire for a higher profit, then the higher price being paid by a customer is the true market price plus higher profit margin. If the reason for the higher costs is increased overhead versus the lowest cost suppliers then the customer is paying the true market price plus increased supplier overhead costs. The key thing is to find at least an approximate true market price by talking to many suppliers and then deciding if it is worth paying some premium above this price to a supplier because they offer some valueadded service. As an example, one supplier may charge $5.00 per pound for a hydrocolloid but offer no real technical support. Another supplier may charge $6.00 for the same hydrocolloid grade but offer good technical support. If the customer buys 100,000 lb. of the hydrocolloid per year, then the customer will pay $500,000 for the market price for the hydrocolloid plus an extra $100,000 per year for the premium of

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technical support. In that case a customer could decide, for example, to pay a consultant $100,000 per year to assist with technical support or even hire a new employee with some experience in hydrocolloids who could build up the knowledge base of the customer company on the use of hydrocolloids in the specific food products of that customer. Or the customer may decide that paying the $100,000 per year is worth it to get good technical support from the supplier. The Most Important Factor in Pricing: Customer Knowledge The following list of reasons does not contain the chief reason to ensure the lowest prices from suppliers: 1. 2. 3. 4. 5.

Size of the customer’s account Length of time bought from the same supplier Relationship/friendship with supplier sales representative Low effort needed by supplier for a customer Geographical proximity of supplier and customer

The chief reason a customer can get the lowest price is customer knowledge of pricing in that specific hydrocolloid combined with the supplier being aware that the customer has a willingness to switch suppliers if necessary to get the true market price. The customers, who know what is the true market price generally by being aware of the price being charged by many suppliers, will be able to get the best prices. Then suppliers are forced to do what only a very few suppliers are happy to do, and that is compete by price against all the other sellers of that hydrocolloid. The five listed factors above have been shown again and again not to be the key factors. In the past very large customers have often gotten the most wedded to one supplier and hence the supplier did not have to offer its very best price even to its largest customer. Length of time with a supplier works by the same principle, the supplier doesn’t feel the need to pass along its savings to long time customers since the customer hasn’t shown the initiative to make a switch for so long. Friendship with a sales representative and nice dinners, etc. only assures the sales representative that the customer will not easily switch and hence the lowest price is probably not necessary. Also, suppliers are happy to sell to a very low maintenance account without feeling any necessity to lower its prices.

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Customers located near a supplier’s factory don’t get any benefit in price by lower shipping costs unless the customer pays the shipping costs, and then the savings are minimal. Often, a supplier will actually try to convince customers saying they should pay more because they have a reliable supplier so close to their own facility! Besides, the supplier quite likely will not even make all of that hydrocolloid in that domestic factory but may import some of it from Asia, for example. Individual Supplier Gimmicks to Sustain High Prices/Profits How does a supplier achieve a very high profit? By selling a product at a considerably higher price than it cost to obtain that product including expenses for all operations of the supplier. How can this be maintained? First of all, price increases can be attempted on customers. Excuses for price increases can include raw material cost increases, labor increases, energy and transportation cost increases, etc. These increases, especially raw material cost increases, can certainly be legitimate. However, price increases sometimes exceed these aggregate cost increases, and furthermore increasing the price to customers every time a supplier’s costs go up only perpetuates the occurrence of high profits for the supplier. If the supplier was willing to accept a lower profit and absorb some of its own increased costs, it would allow the market to stabilize at more reasonable profit margins for the supplier and more reasonable prices for the customer. In fact, if forced to do so, most suppliers will eschew receiving an increased price from the customer if the customer indicates that a new supplier will be sought who will accept the current pricing structure. What this indicates is that the supplier will live with less profit, but only when forced to do so by savvy customers. There are also supplier gimmicks on the cost side. Raw material costs for several hydrocolloids go up and then down again. But do suppliers ever publicly announce a percent decrease in their prices due to lower raw material costs? It is not likely to happen. Also, suppliers sometimes begin to purchase finished hydrocolloids from plants in lower labor cost nations for blending or outright direct sales in the supplier bags to their customers. The costs to obtain that hydrocolloid have suddenly gone down, sometimes dramatically, but again no public cost reduction is announced. Suppliers also have dramatically reduced their operations, decreasing substantially R&D, tech service, sales, and other support

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departments. Again, they have not voluntarily passed on these cost savings to their customers. Costs come down in the hydrocolloid industry only due to competitive pressures, and then only to customers who make themselves aware of their bargaining position due to the competitive nature of the marketplace. In short, beware of the gimmick that all potential increases of supplier costs should be passed on to the customer. Remember, few of the many price decreases experienced by a supplier are ever voluntarily passed on to its customers. Joint Supplier Gimmicks to Sustain High Profits It should not be assumed that any certain supplier is guilty of any anticompetitive practices in collusion with supposed competitors, but such practices have been known to occur in the hydrocolloid industry. In the most extreme cases, two ostensibly competitor suppliers have directly agreed to not pursue each other’s customers to therefore maintain artificially high prices throughout both suppliers’ customer bases. Although it is not appropriate to list particular companies in this setting, the use of an internet search engine will show cases where the U.S. government has imposed hefty fines on companies that were found to engage in such practices. Generally, large customers who suspected something amiss convinced the government to investigate specific hydrocolloid products and the companies who supplied these products at seemingly high prices. Anticompetitive practices were then uncovered by the American government, and the companies were duly punished. A number of other anticompetitive practices have been indulged in by some suppliers. Only one other is mentioned here. Some manufacturers in the industry have secretly bought product from a competitor manufacturer and resold this product to customers without telling them that the product was made in the plant of a competitor and not in their own. This is doubly deceptive to the customer in that the customer thinks he is using product from one supplier that actually is made by a competitive supplier, and also the customer thinks these two companies are each bidding against each other to win the business but actually they are cooperating to get the business at a favorable price to each. Whether these practices are widespread or very rare for the hydrocolloid being purchased by a specific customer is irrelevant because there are very easy ways to ensure that a customer will not be forced to

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pay higher prices due to any potential anticompetitive practice. Many of the ideas presented in this chapter can be helpful to avoid being caught in an anticompetitive snare. The simple precaution for anticompetitive practices is to solicit prices from at least four different types of suppliers, and try to purchase regularly from at least two of them. It would be very unusual for four companies to all have similar pricing in this industry since the prices among suppliers vary so greatly. Advantages/Disadvantages of Spot, Quote, and Bid Pricing Spot pricing refers to the current price a supplier will charge if product is ordered that day or often within a week. If a customer would choose this way of buying product, it could be a low-cost but somewhat unstable means of buying hydrocolloids. For some hydrocolloids, such as guar gum and gum arabic, there are some seasonal trends in pricing based on harvesting the raw materials used to make these gums. If a customer decides to use spot pricing, the best way to do so is to ask the suppliers to give the low and high prices during the last year and the time when these occurred. If the prices are at the lower end of the range, then a decision could be made to buy a several-month supply or even a year’s supply at that point to lock in a lower price. In some cases, the supplier will even be willing to deliver and bill the customer in stages if the customer commits to a specific quantity for the year. Quoted prices are the closest thing to a current list price in the hydrocolloid world, except there is no such thing as a true list price because customer by customer different prices prevail all at the same time for a given supplier. That is one reason why prices are seldom listed on major American or European hydrocolloid supplier websites. Prices are found on the websites of most suppliers of most items, but not hydrocolloid websites. Anyway, at any one time if a customer started to buy from a supplier, the quoted price would usually be valid for a year, sometimes much longer than that. Now the first thing a potential customer should determine is how long the customer could rely on that price if the customer started to immediately buy the product at that price. It may be that the supplier looks at the quoted price as simply a spot price where every shipment would be freshly priced. If the supplier gives an indication that the price should be good for a year or the rest of the year, at least the supplier has taken into consideration the vicissitudes of the marketplace and built

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that into its price. Of course there are no guarantees because a quoted price is not the same thing as a bid price. A bid price has some advantages and disadvantages over spot and quote pricing. The first thing to consider is whether the specific hydrocolloid is at a relative high or low at the time of bidding. If prices are going up, then the customer is well advised to lock in a seemingly lower price, but if the prices are going down then the customer can expect to perhaps pay a higher amount for a whole year or more. Of course no one can really know with certainty which way the prices are heading, and suppliers will have a much better grasp than any customer. Therefore most suppliers will anticipate increasing prices and bid higher to compensate for that but will generally not reduce bid prices much if they expect the prices to decrease. So, on net, the price fluctuations of hydrocolloids are usually better understood and exploited by the suppliers compared to the customers. There is another aspect of bidding that plays strongly, actually very strongly, to the benefit of the customer, especially a customer of medium or large size. That is the need for suppliers to show to their upper management that they are growing their business. Obtaining a bid account of sufficient size is an excellent way to achieve this. By the same token a supplier that already has a large bid account will be very loathe to lose that account to a competitor and therefore have to show to its upper management the reduction of their business. Thus both current and potential suppliers will often reduce their profit targets and find ways to cut costs to obtain a coveted account. The customer should not forget potential collusion of a couple of suppliers and therefore make sure several bids are solicited. Also a comparison should be made if possible to spot or quote pricing to ensure that all the potential suppliers are not excessively padding their bids. One caution is that the use of bidding to achieve the best pricing can be underdone by not treating all bidders fairly. This is discussed later in this chapter. Unfortunately, one other caution must be mentioned about bid prices. At one time, a customer could be quite sure the supplier would honor a bid price, even if the price was a multiyear deal. That is no longer the case in these tumultuous economic times and with the current mentality and business practices of some major hydrocolloid suppliers. It is now in fact the situation that some of the largest and previously most respected hydrocolloid manufacturers have simply reneged on supplying

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hydrocolloids to even their very largest customers at agreed-upon bid prices in the middle of the contract year. This trend has started to make savvy customers take a new look at purchasing under spot and quote hydrocolloid pricing. Also, arrangements are being made between willing suppliers and customers to jointly monitor factors that increase costs and develop equations to allow some price fluctuation on the part of suppliers within new contracts. Of course this only makes sense for customers if the supplier is willing to look at the pricing of hydrocolloids on a more commodity-like basis. How Customers Can Avoid Annoying the Suppliers and Forfeiting Best Prices We are living in a customer-oriented age. Also, nearly all suppliers would like to sell to everyone who would be willing to buy their product in sufficient quantity. And in any buy-and-sell relationship that is not a monopoly, it is the supplier who is expected to do whatever it takes to satisfy a customer. Still, there is a big reason to not intentionally antagonize suppliers and potential suppliers. In the long run, it may lead to not being able to achieve the best prices and services from suppliers. Below are four areas to consider: (a) It is a really good idea for a customer to respond at least once to all potential hydrocolloid suppliers who inquire about its business. It is not necessary to meet suppliers in person but at least respond to them briefly by phone or email. Here are four reasons why it is good to do so: (1) They may actually be a much better supplier of the hydrocolloid, even though a customer may never have heard of them up to that point. That is, they may have excellent prices, technical support, customer service, convenient stocking, more appropriate grades or products for the specific customer situation. They may even have some fairly unique products that a customer would not find out about unless it had some contact with that specific supplier, for example, acid stable guar gum. (2) Unpleasant changes may occur with the current supplier: decreased quality, sharp increases in prices, loss of key technical support personnel, etc. This may be because of a buyout, a plant closing, layoffs, the overall economy in the supplier’s location, or many other everyday reasons. The point is that it is wise to have alternative suppliers lined up before they

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are desperately needed. (3) The customer’s purchasing or technical people may switch jobs and end up in a company that utilizes the potential supplier as its key supplier. If a new employee was rude or dismissive of the supplier in a previous company, it will be somewhat awkward to later have to embrace those same supplier personnel. The food industry in general is a notoriously unstable employment area and is also a surprisingly small field where many people know one another. It is not a good idea to burn bridges. (4) Contact with potential suppliers is a great, no-cost way, except for a few minutes of time, to learn more about the hydrocolloid world. Ask for price quotes and about technical and business trends and compare the answers to the current supplier. Ask any tough questions the current supplier can’t answer. It is acceptable to tell a potential supplier not to call again for a year until a contract expires or that the supplier should wait until the customer makes the next contact. Set the terms for future contact and expect the supplier to abide by that, but save the contact information because it may well come in useful in the future. It may surprise some medium size customers to know that most larger customers are aware of and solicit contact with many suppliers, even ones that are not that well known. They know it can only benefit them. (b) Treat sample submissions respectfully. If 10 hydrocolloid samples were tested by a customer, and only two passed all the tests, it is still a good idea to talk briefly to the suppliers who submitted the other 8. First, the suppliers at least know that the customer took the time to test the samples. Second, if the supplier is given some feedback on how it failed the tests, it will help the supplier to know what changes to make for a future sample submission, even if the customer doesn’t expect to run any more tests at that point. Things may change in the future. (c) Bidding for accounts can be a very time intensive process for suppliers. If the customer only uses bids as a leverage to get its current supplier to lower its price, then other suppliers will eventually realize that bidding at that customer is a no-win situation. They may continue to bid but won’t offer their very best prices anymore. A better approach is to give a potential supplier a part of the business if its bid is much better than the incumbent company. Even a 10% share will give them an incentive to bid low again the following year in hopes to increase their share of the business.

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(d) Value the time (and therefore the money) of suppliers and potential suppliers. Have a central repository of data sent by a supplier instead of having several people from several departments all call the supplier to ask for the same documents and information. Also, if the supplier has international organization for standardization (ISO) or good manufacturing practices (GMP) certification, which requires certain practices in manufacturing, see if those certifications would be acceptable in lieu of long and complicated customer generated forms. Also, keep track of samples a supplier may have sent so that new requests for the same sample are not constantly sent. Customer Factors Influencing Supplier Costs Although price is of course based on many supplier factors, such as overhead and expertise in manufacturing, customers also can have an influence on supplier costs. In this day and age, an important influence on supplier costs is cash flow. If a customer requires the supplier to hold stock inventory in the customer’s country, and hold a sufficient supply for say 3 months, and then pays in net 45–60 days, there are large carrying cost charges for the supplier, which must in some way be passed on to the customer. Hence, the supplier may end up charging up to 20% more for the product because of these costs. If the customer could accept deliveries directly from the overseas plant and pay on receipt, this would lower carrying costs tremendously for the supplier, which in turn could charge significantly less for the product to that customer. A customer often has cheaper means of getting funds than using the supplier as its bank. The supplier will find a way to pass on its carrying charges at a much higher rate than a bank. It also may stop some less cash-rich suppliers from even bidding on that business, and then it’s back to the semicompetitive days for the customer. Other factors influencing costs include having to label all individual bags with the PO number, requiring removing and repacking all bags on pallets. Special testing adds to costs. Hydrocolloids, for example, are not microsensitive products, yet some customers require every batch to be tested for Salmonella, Escherichia coli, and other pathogenic bacteria, even though hydrocolloids are not carriers of these hazardous bacteria and could be tested for these bacteria maybe once a year.

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Understanding How to Avoid Price Increases From Suppliers and Gain Price Decreases from Suppliers Announced price increases are usually more a wish by the supplier than a fact. It is interesting to note that actual prices for hydrocolloids are never publicly disclosed by most suppliers, but suppliers think, for some reason, that percentage price increases must be made public by media announcements. Often this is done as a signal to competitors and it sometimes happens that suppliers ask for a direct meeting with a competitor at its head office to announce that it will raise its prices by X percent! But fortunately for the customer, these price increases often do not stick in the new competitive marketplace now extant in this industry. A few months after price increases are announced, a supplier will generally have an internal meeting to discuss how much of the price increase it had to “give back.” Often it is most of it. The customers that balk at the price increases are frequently allowed to continue paying the old price, especially if there is legitimate threat that the customer will bolt to another supplier. At the first indication of a price increase a customer should, if it hasn’t already been done, get price quotes from competitor suppliers. If the prices of the competitors are lower than the current price then it should be possible to at least get the current supplier to waive any announced price increase. In summary, an announced price increase in the hydrocolloid world is certainly not a forgone conclusion if questioned. Price decreases are generally not announced to customers. If increased raw material costs or labor costs are used to justify price increases then decreased raw material costs or decreased labor costs due to opening a new plant in a low–labor-cost country should lead to price decreases. They do lead to cost decreases for the suppliers but generally only by customer action do they lead to price decreases for the customer. The most obvious way to gain a price decrease is to find a lower cost supplier and announce to the current supplier that a switch to a new supplier is planned. Suddenly the current supplier may offer to match that price and finally the customer may get a price closer to the true market price. Amazingly, many customers will then accept the current supplier’s lower price and not feel upset that for all the previous years they had been paying too much. There is one danger in accepting a much lower price from the current supplier. That supplier may not be happy

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with the loss in profits and may try to start substituting a somewhat cheaper-made product, and this could cause technical problems for the customer’s products. The Future of Pricing Predicting future trends can be difficult in any arena. But it is somewhat easier in the hydrocolloid world because the hydrocolloid world is generally far behind other industries and therefore some of these trends could be gleaned by seeing what exists in other industries today. Therefore on the basis of other industries, it could be predicted that hydrocolloid suppliers will move to more transparent pricing, including putting real market prices on web sites for all to see. There will, in many ways and for many reasons, continue to be a movement toward true market pricing in hydrocolloids, at least for aware customers. Suppliers who offer many premium services to customers will clearly advertise the value of these services to potential customers to justify their pricing above true market pricing. But only slightly higher than true market prices will likely be available in the future for most of these added services. Still, some niche suppliers may justify substantially higher prices for extensive technical and other services to customers. Grades will become more fully standardized, like other commodity ingredients. This will also help prices to become more favorable for customers. Logistics will increasingly become more sophisticated with just-in-time deliveries and with suppliers having full capability to see a customer’s actual remaining inventory and scheduling deliveries automatically at prearranged inventory levels. This will help the cost structures of both suppliers and customers. Other trends very specific to the hydrocolloid business include the following. An increased amount of new hydrocolloids will appear with increased specific functional advantages. Part of this trend is due to the relative ease of getting “self-affirmed generally recognized as safe (GRAS)” approval in the United States. Part of this trend is also due to the fact that exact requirements for beneficial hydrocolloids are well understood and sought for specifically. In other words, a company may try to develop a hydrocolloid with good emulsifying properties but that is cheaper to make than propylene glycol alginate (PGA) and can fit a natural food label claim. PGA, since it is chemically modified, is not considered natural.

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From a pricing point of view, the appearance of new hydrocolloids in the long-term must be favorable to customers. There is some temptation for a supplier to try to gain high prices for a new product like the monopoly companies of old. But new products must compete with existing products and unless the functionality can be purchased at a reduced price, customers won’t take the time and effort to evaluate a new product. Also, it is difficult in this day and age to maintain a new product for long without other companies being able to match the technology. Most of the new products of the future will not be able to gain worldwide patents that would restrict their production to one company. A key point for hydrocolloid buyers is the increased wisdom in keeping good contacts with a number of hydrocolloid suppliers since this will better assure that the buyer will be alerted of new hydrocolloids that might benefit the company and possibly save money for the customer.

The Third and Final Key of Purchasing: Supplier Screening From all the suppliers who can provide high-quality products of the needed grades, and can do so in a highly cost effective way for the customer, a final determination must be made which suppliers will be selected by a customer. The aim of the third and final key involved in hydrocolloid procurement is to determine how to evaluate suppliers in a logical and systematic manner. Each supplier has some other inherent qualities that the customer must evaluate in order to decide if the supplier is acceptable. Each supplier may also offer some benefits or services to its customers that the customer may or may not decide to utilize, and these may also influence whether a specific supplier is chosen by a customer. This is the essence of key three—the supplier evaluation. This section is devoted to assisting the customer in understanding the qualities of a supplier and the benefits a supplier may offer, what each of these entails, and how to rate each supplier on these qualities or benefits. Sixteen parameters are used to make the supplier evaluation. The first two parameters relate to supplier products, prices, and quality. These parameters, which are explained in depth below, are most important in deciding whether a supplier is even a possible choice for a customer.

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The final 14 parameters of the supplier evaluation protocol are issues which historically have been significant in making a customer happy with a supplier and willing to stay with a supplier. For each of these parameters, a scale of three is used to rate a supplier on each parameter, with one being the lowest score and three being the highest score. The ratings of one, two, or three are given descriptions for each parameter. The 16 parameters, one by one, are explained starting in the next section. For each parameter, the meaning and importance is explained, the terms for the three-point scale are expounded, and the ways to determine where a supplier falls on the three-point scale are reviewed. Please note that each customer must decide what the acceptable minimum score will be for each parameter for each type of hydrocolloid supplier. The customer should make this determination based on the relative needs the customer may have or not have for a specified supplier quality or benefit. A customer may also have different standards for, say, xanthan gum versus pectin, based on the relative help a customer may need from the supplier of xanthan gum versus the supplier of pectin. At the end of this section, a supplier evaluation form that summarizes all 16 qualities and benefits is found. The customer can circle on this sheet the minimum levels desired for each of the 16 items for each hydrocolloid it buys and then use that sheet to evaluate potential suppliers of that hydrocolloid.

Product Categories and Types In the first key, the goal was to begin to decide the hydrocolloid type, category, and grade for each specific hydrocolloid need. So, of course, it is necessary in evaluating each supplier to determine if the supplier markets the specific hydrocolloid and grade needed. But at the same time, it also makes sense to determine if that supplier also sells any other hydrocolloids the customer buys. Further, it is advisable to determine two other things. First, does the supplier sell other product categories for that hydrocolloid? For example, if it sells functional blends, does it also sell pure hydrocolloids or, if it sells application blends, can it also sell a functional blend or pure hydrocolloid? The reasoning here is that food product developers are often given assignments to reduce the total cost of formulations. As the food product developers gain some confidence in their understanding of hydrocolloids, they may decide to reduce the

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cost of the hydrocolloid component. If the current supplier sells various product categories of that hydrocolloid, the supplier will be able to both assist the R&D group and continue to serve as the supplier, if the R&D group substitutes a lower cost product category for the hydrocolloid in question. It is also helpful to ask the supplier if it sells other related hydrocolloid types. Another way for the product development team to reduce costs is to substitute a lower cost gum for a more expensive hydrocolloid, even if it is a partial substitution. If the supplier sells these alternate hydrocolloids it will be able, and perhaps more importantly, willing to guide the R&D team of the customer. Some of these potential substitutions would include guar gum for xanthan gum in some cases, konjac for locust bean gum, and semirefined carrageenan for refined carrageenan. The evaluation for supplier’s capacity for product types and categories would include three pairs of selections. The first would be a listing of hydrocolloids and blends that the supplier sells which the customer currently buys or needs to buy. If the supplier sells all the required products then this should be noted. Second, it would list the categories of products that the supplier sells: pure hydrocolloids, functional blends, synergistic blends, and application blends. The customer may decide to leave some of these off if they really have no potential need for them. The final section would list the full list of hydrocolloid types that the supplier sells. Not only would this last part be useful for potential substitution, but also for new projects where these might be needed. Before leaving this evaluation category, a few words follow about whether to choose one supplier that sells many gums or one that only sells a few or even one. There are advantages to having a supplier who sells many gums, but only if they understand all of them well, and the sales, technical service, and applications people are able to master all of them; and this is rare. If a supplier does sell several gums, it is important to determine during the technical and applications evaluations whether they understand all of them well. In some cases, a company may acquire another company and its product line, then lay off many of the acquired company’s staff to save costs, and be left in a position where the sales and technical people of the original company must now quickly learn a new product line. They usually never learn the new products as well as the original ones. If a company only sells one or two gums, they may know them extremely well and this can be good. However, they

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may not have good perspective on the overall field and how other gums compare and contrast to the ones they sell. In that case, they may not be able to give unbiased advice. The best situation is one where a company both sells and thoroughly understands several gums. The next best is a company that only sells one or two gums but knows them very well. The least desirable is a company that might sell several gums but doesn’t understand all of them very well. It is desirable to get price quotes not only on the product category and grade of primary interest at the moment, but also prices on other potentially relevant hydrocolloid types, categories, and grades. For one thing this can help the R&D department have some idea how other potential hydrocolloids compare with currently bought hydrocolloids. As mentioned earlier in this chapter, it is always a good idea to get as much price information as possible in this business, where price information or the lack thereof has so often been used to gain large profits off the backs of unsuspecting customers. Product Quality Product quality is the most important evaluation of a supplier. There are no gradations available for this parameter. Either a supplier’s product is of acceptable quality or not for a given customer. To determine this, it is best for the customer to test the hydrocolloid or to send it to an independent lab for testing. Two different types of tests are recommended. The first test should be a verification of the important quality assurance tests such as viscosity and gel strength. As described in Chapter 10, sometimes the viscosity is tested a little differently by a supplier and a customer. It can be that the test method is purportedly the same, but subtle, unwritten differences may exist in exact methodologies that can have a large impact on the test result obtained. The most common example of this type is the viscosity method where one lab mixes the sample immediately before measuring the viscosity and another lab doesn’t at all or doesn’t mix it in exactly the same way. Because hydrocolloids are quite thixotropic, the viscosity measurements can be markedly different because of this small but important testing methodology variation. It is best therefore before testing a supplier’s hydrocolloid to ascertain that both the supplier and the customer are using exactly the same techniques for testing. In this way the supplier can precheck the grade it

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thinks is the right grade to make sure it will be the actual right grade for that customer based on the customer’s test methodology. The customer must also be sure that the potential supplier actually includes in its specifications all key functional tests the customer deems important and knows the range for each test the customer will accept. Besides basic functional testing, the customer may also want to test the product in some of the foods made by the customer. For the foods the customer should also check functional properties such as viscosity or gel strength and compare these results to the current supplier. In some cases, a hydrocolloid will pass the QA-type tests but fail in the food application tests. This may be due to the fact that although the QA tests show that it is in the acceptable range for these important parameters, it may still be outside the acceptable range for actual use in foods. The reason for this is not that hydrocolloids are some fancy magical entities that can’t be fully explained by QA tests but rather the QA specifications and tests aren’t sufficiently detailed or precise enough for the customer’s application. For example, a common mesh size designation might be 95% through 80 mesh. Two suppliers might both be at 96% through 80 mesh but one supplier may also be 95% through 120 mesh and the other supplier only 25% through 120 mesh. The first supplier’s hydrocolloid in a food may hydrate quicker; and if the mixing time is not long enough, the second supplier’s product may not hydrate adequately before the mixing step terminates. In that case, the first supplier’s product gives a higher viscosity to the food than the second supplier’s product. If the specifications were made more extensive to also give a mesh requirement for 120 mesh, then all suppliers could be sure that their products passed this more appropriate test. The customer should also verify that the sample sent by the supplier is from a regular production batch so that it is typical of products being sold by that supplier. If the customer decides to buy from that supplier, the customer may want to carefully test the product from at least the first couple of shipments before it is actually used in production. Certifications Hydrocolloid customers often ask suppliers for one or more certifications. Most reputable suppliers will have at least some of the major international certifications. These include ISO standards, GMP, Kosher, and other more regional or application specific certifications. Having

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a certification from a respected agency does indicate to the customer that the supplier has had independent determination that the production facilities and manufacturing processes pass the high standards of these international agencies. This can give the customer some comfort level that the supplier’s products are being made in legitimate facilities. It will not verify that the grades sold will match other products sold in the marketplace in all applications, and that is why testing is still required by the customer. The logical focus for the customer should then be on customer-specific testing, primarily in the customer’s applications. It makes no sense for the customer to waste time double checking good manufacturing protocols such as screens for windows. Let the international testing agencies do all that since they are best equipped to check these things and they are very stringent in their requirements, if only to protect their reputations as testing agencies. A customer must first decide what certifications it considers vital. Sometimes a supplier may have a major certification like ISO but the customer will ask instead for a more regional certification, that is, not as in depth as the ISO requirements. The supplier may not have the regional certification. In the end, it is the customer’s decision but it will add to the cost of the hydrocolloid if duplicative plant evaluations are required of the supplier. It may also limit the customer’s options for suppliers that could impact price as well as certain supplier benefits that may not be offered at the same level by all suppliers. The three-point scale for certifications has as the first level that the supplier does not have all the customer’s required certifications. The second level is that the supplier does not have all of the certifications but all missing ones have been applied for and are in the process of being completed. The customer may want to check on the timing for completion if this is acceptable. The third level for this parameter is that the supplier already has all requisite certifications the customer requires. Clarity of Communications This is a very important aspect of any relationship; but for a supplier and customer, it is crucial. For verbal discussions, it must be clear exactly what each side is saying. An important aspect to this is how clear and understandable is the English or whatever language is used for the business relationship. If English is not the native language for a supplier, then the customer must be sure there will not be problems

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due to this in the future. Obviously the sales representative is the initial key contact and the clarity of this communication is the first indicator of how this parameter will work out for the customer. However, the supplier may need to have other members of its company also contact a customer, and these people must also have very good ability to speak in English to avoid potential problems. Besides spoken language, it is important to have clear written language skills, both for technical discussions and business-oriented discussions, including any contracts. And it It is not only the communications of the supplier to the customer that are important. The customer’s communications, spoken and written, must also be clearly understood and acted upon. Also, one of the dangers of having a situation where the clarity of communications is not ideal is that at times it is decided by both sides not to try to explain some complex point, and this negligence can have future negative repercussions. It is not necessary or even desirable that all suppliers be U.S. companies with all operations in the United States and that all of their employees be American. This would severely limit available top-notch suppliers, eliminating most of the best suppliers of hydrocolloids. It would result in drastically higher prices bringing back monopoly-oriented pricing in some cases. We live in a global economy and therefore have to work with companies whose operations might span the globe. What is necessary is that the supplier has arranged that people with strong English communications skills, both verbal and written, are utilized in all positions where communication with a customer is necessitated. If this is done, then everything has been shown to work without episode in many supplier/customer relationships. Besides language differences, there are two other situations that impact clarity of communications. The first is that some suppliers are so inexperienced or disorganized that they cannot explain things clearly because they literally are not operating their companies in a clear and organized manner. In some cases, this is due to too many layers of management, too many new employees, or the confusion that sets in when a supplier was recently acquired by another company. The second situation is where a supplier purposely tries to obfuscate communications because it wants to hedge whatever it says because it is not sure it can fully keep its commitments to a customer. These may be logistical commitments, technical service commitments, or even product quality commitments. Obviously, both of these situations can be even more serious than language barriers.

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Clarity of communication by a supplier can be tested in a number of ways by a customer. For example, it can be effective to repeat back what the supplier has said and ask if that is what was meant, or the supplier can be asked to repeat back what the customer communicated. For this parameter, the three ratings available are terrible, acceptable, and excellent. Terrible clarity will be obvious to the customer. The supplier’s representatives will have difficulty explaining themselves either verbally or in written communications. In some cases, a customer will accept this situation to save money but it can be risky. For the acceptable level, all the communications are understood with some effort and care. For excellent communications, the clarity is obvious and flawless, requiring no expenditure of energy on the part of the customer.

Ease of Communication This parameter is an amalgam of a number of important factors related to communications between a supplier and customer not related to clarity. One of the factors involved here includes the supplier and customer being in the same time zone to facilitate easy communication. Other factors include how much the supplier and customer are on the same wavelength as far as the types, frequencies, and reasons for communications. Does the supplier accept the customer’s timelines for issues related to supplier approval or does the supplier constantly call the purchasing agent to try to move things along? Does the customer prefer telephone but the supplier always emails? Does the supplier always try to pry more information from the customer than the customer is comfortable in sharing? This is a surprisingly important parameter, especially if the customer and supplier do not see eye to eye on communications. The three rating levels are difficult, good, and exceptional. Difficult communications will manifest themselves usually in the customer starting to feel some annoyance with dealing with the supplier, even if it is hard to pin it down to one communication or issue. Good communications will generally result in an acceptable level of comfort, while exceptional ease of communications will make the customer look forward to all dealings with that supplier. The customer will feel that the supplier understands how to make all communications go smoothly and effortlessly.

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Logistical Facility At the present time, ingredients are shipped halfway across the world to food manufacturers, and no one wants to hold inventory for long due to cash flow constraints and drives for greater efficiency in operational costs. Logistical facility primarily refers to hydrocolloids shipments and how convenient, reliable, and effortless these shipments can be for the customer. The three ratings for this parameter are complicated, typical, and superior. A complicated logistics supplier will expect the customer to order full containers of greater than 10 tons and then expect the customer to pay for this before it ships, handle all customs clearance and local delivery details, and wait 6 weeks for the product to be made and shipped. A superior logistics supplier will ship product the same day an order is placed for next day delivery from regional warehouses within the customer’s country in exactly the quantity needed by the customer. The typical logistics supplier will fall somewhere in between, require more notice from the customer on delivery, and often want the customer to provide a fixed schedule for shipments.

Supplier Technical Support Technical support, also called technical service, refers to the ability of suppliers to assist the customer in using the hydrocolloid that they sell. Understanding exactly how the hydrocolloid functions in the customer’s food product is called applications support and is reviewed in the next section. The level of technical support offered by a supplier to customers will be divided into three levels. These are essentially no technical support, modest technical support, and extensive technical support. It is up to the customer to decide what level of technical support is needed from the supplier for any given hydrocolloid purchased. In the first category, suppliers provide essentially no technical support. This may be because they know very little about the hydrocolloid besides how to make it and how to do basic quality assurance tests. Also, some suppliers do not offer much technical support because they are located in a different part of the world from the customer and there may be language barriers to communication. If a supplier provides no technical support, the customer must already know how to fully use

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this ingredient and also be able to make any future decisions about this ingredient without benefit of the supplier’s input. Although this might sound like a difficult situation for a customer, it is in fact the case that many customers never really ask the supplier for any assistance with the hydrocolloid. They may consider it a savings to not have to pay for technical support they rarely or never utilize. For this, they may prefer to hire a consultant to help them with hydrocolloid issues. Some customers prefer the second category of technical support from hydrocolloid suppliers. In the category of limited technical knowledge, a supplier will be able to explain the basics of how their hydrocolloids work and do rudimentary troubleshooting. They will be able to explain the basics of dispersion, hydration, and gelation. They will be able to guide the customer concerning stabilities with acid, salts, and heat and understand some key interactions with other hydrocolloids. Most of the times that customers need technical help, this will be sufficient. The supplier with expert technical service will be able to do extensive training of customers and fully explain important phenomena related to the hydrocolloid and how this compares to other hydrocolloids. When necessary, this help can be crucial to a customer, but often it is not necessary, either because the customer has already received good training or because the customer’s use of the hydrocolloid is in applications that tend to be nonproblematic. For the purchasing agent, it may be necessary to consult with the R&D or QA people to get a clear understanding of where a supplier may be on the expertise continuum, both for technical support and applications support. Just because a supplier has a large and wellestablished tech service and applications department doesn’t mean they are that knowledgeable in practical ways needed to help customers. Hydrocolloids take many years to learn well and not everyone does learn them well even after many years. Technical service employees with less than 10 years of experience often have not fully learned the intricacies of hydrocolloids. Sometimes, smaller suppliers with smaller staffs have stronger technical departments because they have veterans of many years’ experience in the hydrocolloids world. One last thing should be mentioned about technical support. Although a customer may not need much technical support, it can be reassuring to know that the supplier has a very strong technical support contingent. The reason for this is it can be an indicator of the

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importance of technology to that supplier in general. It can indicate that the company values strong technical understanding and this can carry back all the way to manufacturing and quality assurance. If difficulties arise in the future with that supplier, and difficulties do arise at times with many hydrocolloid suppliers, they will have the wherewithal to deal with any issues because of their strong technical emphasis.

Supplier Applications Support Food products made with hydrocolloids are referred to as food applications by hydrocolloid suppliers. Suppliers vary greatly in knowledge of these customer products. It is useful to divide suppliers into three categories with reference to knowledge of the specific food applications of each customer. The first category of suppliers has little or no knowledge of a customer’s application. These suppliers do not have much specific knowledge of how their hydrocolloids function in a specific food, what other ingredients are in the food, how the food is processed, or what kind of shelf life would be expected. The second category has a moderate amount of knowledge. These suppliers might have some idea of how the hydrocolloid functions in the food and what use levels of hydrocolloid would be reasonable. They would tend to have more limited understanding of other ingredients, processing, and shelf life. The third category has an extensive knowledge of the hydrocolloids’ function in the foods, other ingredients involved, and processing and shelf-life issues. These suppliers would have the knowledge to make a similar quality food product, though they would tend to have little concern for precise flavors, spices, colors, and other issues not directly related to textural and stability issues, and only flavor issues related to flavor suppression caused by hydrocolloids. Once again, it is up to the customer to decide which type of supplier is preferred of the three categories available. If a customer is very confident in its ability to make its own food products using hydrocolloids, the customer may find the first category of supplier acceptable. The prices these suppliers could offer would tend to be the lowest since they do not need to use part of the hydrocolloids’ price to finance an expensive applications staff, labs, and pilot plants.

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A customer may choose the second category of supplier for two reasons. First, a supplier who understands the customer’s product can be helpful if the customer suddenly has problems in production with a product or has problems with related new products being developed. The supplier can do some useful troubleshooting in such cases. Also, sometimes manufacturers change hydrocolloid-processing procedures, which can happen for a number of reasons. Suppliers, who understand their customer’s products somewhat, will be more cognizant of how changes in their hydrocollsoids might impact the functionality of their hydrocolloid in specific foods. Customers choose the third category of supplier when they need serious help making the product or expect the supplier to help with R&D on new projects. In these cases, it may be worth paying the extra premium on prices to buy from a supplier that has extensive applications experience. Suppliers who have the most knowledge of specific-customer products are not necessarily the largest suppliers of a hydrocolloid. There are much smaller niche suppliers who may specialize in certain market segments such as meat or frozen desserts. These suppliers may have the greatest amount of experience in these food products. There is a negative, however, to the customer when intimately discussing the customer’s food product with a supplier. The knowledge that is shared with a supplier will eventually be obtained by the competitors of the customer. Hydrocolloid suppliers are trying to sell to a number of customers in the same industry. Knowledge they learn from one customer will become part of their institutional knowledge and this will eventually get to the competitors of the customer who shared that knowledge with the supplier. That is the risk of “joint projects” between a customer and a supplier. Confidentiality agreements do not help to mitigate this situation in the long term. That is because food industry companies are very unstable employers, and hydrocolloid companies are among the most unstable. Employees are often terminated or they themselves seek new employment. The employees of suppliers will most often end up working for another supplier since this is where they have the most useful experience, or possibly even at one of the customer’s competitors. Although employees may be threatened with legal action if they reveal their previous employer’s trade secrets, it is almost impossible to trace the transfer of knowledge that was obtained from the customer of a previous supplier. The net result is that nearly all knowledge

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shared by a customer with a supplier eventually gets to the customer’s competitors.

Ethics of the Supplier When there are many factors involved in the supplier/customer relationship, when not all factors can be totally understood by the customer, when trust becomes necessary on one or many levels, when change is certain to occur in the future in this business, when stability is not the hallmark of the hydrocolloid business, then the ethics of the supplier become a major factor in deciding from whom to buy. Ethics is something that is taught in business books, and companies have various ethical standards, but this is not what is meant by ethics in this connotation. Ethics for a supplier means that first of all, the supplier will be honest with the customer and not try to deceive the customer. Deception can take many forms including those where the customer is given the wrong impression. A supplier might say it has a plant in a given state in the United States or a nation in Europe but not tell the customers that the product they will buy is actually partially bought from a plant in China that is not even owned by the supplier. An ethical supplier will not sell products at much higher prices to one customer only because that customer is not as aware as other customers of the same size and type that current pricing by the same supplier is much lower than the price they are paying. These are but two of a myriad of ethical or unethical practices a supplier may use in its dealings with its loyal customers. Poor, standard, and outstanding are the three ratings classes for suppliers. For poor ethics suppliers, deceptions and lies will become apparent when the supplier is pressed on some issues. The customer can ask if the supplier would sell any products not made in its plants, for example. There is nothing really wrong with this practice; but if the supplier denies it would do so, it should be treated with skepticism since most suppliers now sell hydrocolloids obtained in different ways. The customer can also do a search engine search to see if the supplier has had any antitrust actions against it in the past 25 years. For standard ethics, the supplier will not be obviously deceptive but will not go out of its way to guard the interest of the customer. Most hydrocolloid suppliers traditionally have fallen somewhere in the range of poor to standard in the ethics continuum. An outstanding ethics

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supplier, by contrast, will take the customer’s interests at hand. When prices for raw materials drop, for example, this type of supplier will preemptively lower prices for its loyal customers. The ethics of a supplier will not be obvious in many cases unless some careful questions are asked about its operations and business practices. Most customers either don’t know how or don’t think they need to investigate a supplier’s ethical proclivities, especially if the supplier is well established in the industry. However, even a few simple questions such as whether gums are ever obtained outside of their own manufacturing facilities or how the supplier passes on to customers decreasing costs when these occur, can shed a lot of valuable light on the type of company the customer is actually dealing with. A useful technique is to ask Supplier A a number of questions about its operations and gum sourcing, etc. Then ask Supplier B the same questions about Supplier A and compare the answers. Supplier A might, for example, claim that it only sells gums made in its own manufacturing sites in the United States and Europe. For example, Supplier B, an Asian company, might state that Supplier A has regularly bought gums from Supplier B for the last 10 years. The suppliers all know each other and what each is doing because the hydrocolloid world is surprisingly small, self-contained, and actually quite incestuous in its operations. That is why supplier ethics can be so crucial for a customer.

Orientation of Supplier Suppliers can be divided into those that are very supplier-oriented, those in the middle, and those that are customer-oriented. What does this mean and why is it important? As reviewed in the hydrocolloid history section, at one time the industry had monopolistic tendencies. During this era, suppliers tended to dictate most things to customers such as grades, prices, etc. Of course, to get new large business accounts, suppliers would try to develop new grades with specific customer needs in mind at times. Eventually customer-oriented grades and customer-oriented pricing became much more prevalent in the competitive era. But there remains a mixture of attitudes among suppliers to this day. The customer-oriented supplier will sell any grade, blend, or other mixture that a customer needs, price at levels where the customer gets the best deal, and offer whatever other services the customer may need.

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This type of supplier is always thinking about how to make things easier and better for its customers. On the other end, the supplier-oriented supplier thinks in terms of its established grades except for its very largest customers, looks for high profits, and restricts what services it offers except to its very largest customers. In the middle of this spectrum is the middle-oriented supplier. Of course every supplier will claim to be customer-oriented, but a shrewd customer will try to push a supplier somewhat to see how willing the supplier would be to do things according to the customer’s wishes. A customer can find out where a potential supplier exists on this continuum by asking if the supplier would make a special grade, would package it in special package sizes, would price a blend based on the costs of each component, etc. Caring/Responsiveness/Respect This parameter might seem to be correlated to the supplier orientation, but a very supplier-oriented supplier might still show a lot of caring and responsiveness to its customers. There are also very customer-oriented suppliers who don’t show much caring or respect to their customers. If a customer is the largest buyer of a hydrocolloid in the world, every supplier acts in a very caring and responsive way, at least seemingly. However, for even other large customers, and definitely for mediumsized and smaller accounts, some suppliers still seem to act in a way that indicates that they really care about that customer, and some seem less inclined to be caring and responsive, or even respectful. When a supplier seems unconcerned with being helpful, courteous, concerned, and interested in the requests or needs of the customer, it can be a sign that the supplier does not care that much about that customer account. This could be, for a number of reasons, the most obvious being that the customer is not large enough to impact the bottom line for the supplier very much. There are other reasons, because some large customers also report an unconcerned attitude by certain suppliers. Another reason could be that many employees of the supplier are not happy, perhaps they were just acquired by another company or the supplier has had a lot of layoffs, or is a very unpleasant place to work because of internal politics. Sometimes it could even be a cultural issue where a company from another country doesn’t understand American ideas of courtesy and respect, or it could be a very arrogant American company whose

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thinking is that customers should be happy that the famous supplier is willing to sell to them. This is actually one of the more important reasons why customers try to switch to a new hydrocolloid supplier. How many times is it heard that customers simply don’t like dealing with Company X, even if it is the largest supplier of a gum, or maybe especially because it is the largest supplier. The rating scale used for this caring parameter is little, acceptable, unusual. On the positive side, unusual caring and respect can be shown by suppliers by means of careful attention to all customer needs, pleasant supportiveness for customer initiatives, and a willingness to make some sacrifices to keep the customer very happy. Respect and caring are two-way streets, of course. Customers who treat all suppliers in a respectful and caring way will find they will bring out the best behavior in many suppliers also. Future Adaptability Things change quickly now in the business world, and the hydrocolloid world is no exception. Not all changes can be predicted or anticipated. Most of the large hydrocolloid suppliers of the past are no longer in business (some are now divisions within other companies but with mostly different people and business models), and several new companies with new business models have arisen from nowhere to become important players in this field. Three things can be stated with certainty. First, changes that are not fully predictable in the hydrocolloid world will impact every hydrocolloid company. Second, new entities will continue to arise that will intentionally shake up the current players in the field and offer new opportunities to savvy customers. Third, internally most individual hydrocolloid suppliers will have unique problems, complications, and opportunities that impact that particular supplier. A customer may want to ensure that its chosen supplier is adaptable because adaptability in the past has signaled success for certain suppliers while others plummeted due to lack of adaptability. The ratings for this parameter are nonadaptable, adaptable, and leader. Nonadaptable companies can be easy to detect. Ask a supplier where it will source hydrocolloids once it can no longer operate its antique American and European plants and a nonadaptable supplier have no good options. Ask them what it would do if health concerns were suddenly raised by

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some consumer group about one of its products. Ask the supplier what it would do if food companies suddenly found a cheaper alternative to the product they currently sold to these customers. Adaptable companies would have answers to these types of questions and many others. Leader companies would actually tell customers how they are planning for improved products to the current ones they sell and planning for more modern facilities in low–labor-cost markets to replace current outdated domestic plants. They would have alternate products ready to go if for some reason a current hydrocolloid they sold had some public relations problems. Innovativeness Adaptability often means reacting to what happens in the world, while innovativeness means coming up with new advancements as a general course of business. Innovativeness is an overall attitude or lack of attitude within a supplier. It involves more than technical advancements to products, though this can be important. It is the attitude, mentality, and operational approach to every aspect of its business, and what it does for a customer, as being subject to creative improvements and advancements. The three-point rating scale has the designations of impaired, open to it, and innovative for this parameter. Impaired means that except for tweaking of its product line and the like, that supplier should not be expected to advance major new trends in the gums business. Open-to-it type companies would like to be innovative and like to talk about it, but often need to be prodded by a major customer to come up with something novel. Innovative suppliers creatively think of new ideas as part of their daily outlook in the hydrocolloid world. They come up with new concepts on their own and also innovate on the basis of input from customers. These types of suppliers are always thinking of the next ideas in the often laboriously slow-moving field of hydrocolloids. Smaller and newer companies tend to be more innovative. They have less invested in the old infrastructure that bigger and older companies must try to utilize until fully depreciated, and old product lines that their plants are designed to manufacture. Older companies tend to be better at tweaking current product lines with small improvements rather than coming out with major innovations. Also newer companies tended to come into existence with some innovations that gave them a chance

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to compete with the old-line established companies. But innovation also comes from experience, especially experience at several diverse companies in the hydrocolloid field. If any company has key employees that have worked at four or five different hydrocolloid companies that gives that company a large impetus toward innovation. Those multicompany experienced employees have seen several different approaches to running a hydrocolloid business and can use that background to synthesize a new and better approach. On some level, however, people are either innovative by nature or not, and training that teaches innovativeness is overrated, at least in gums. The most usefully innovative employees are found to be naturally creative individuals who are also diversely experienced in the complex world of gums. The customer must decide how important this category is to their future. A customer must also be interested in being innovative with its product lines or it makes more sense to stay with a non-innovative supplier who will match it in its desire to maintain the status quo. Of course the customer’s competitors will then bring out the innovations with the help of the innovative hydrocolloid suppliers. To gauge the innovation parameter in a supplier, ask a lot of questions about new ideas that the supplier has and what new products or other innovations it is making available. If the answers are new blends or extensions of its product line, the company is not in the innovative category. If they are promoting totally new gums and ideas that you have never heard of before, then the supplier is clearly innovative. It won’t be difficult to tell innovative companies from non-innovative ones. Industry Knowledge A hydrocolloid supplier can be a useful source of relevant information about large segments of the hydrocolloid industry, and its doings, if it has good contacts in the industry and is willing to share this information with its customers. Among other benefits, it can direct the customer to the best suppliers of hydrocolloids it does not itself sell and also warn its customers about suppliers who are having problems and should be avoided. This type of gossip can be very beneficial to customers by giving them more of an inside angle on the hydrocolloid world that they otherwise would not be able to have. Also, major trends in the hydrocolloid world, whether positive or negative, can be learned from

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a savvy supplier willing to talk. This can help the customer better plan for the future with its own hydrocolloid portfolio of purchases. The three categories for this parameter are clueless, elementary, and great awareness. Remember that this does not refer to the knowledge of the supplier necessarily, but can refer to the supplier’s willingness to talk frankly to its customers. Some suppliers have great awareness but act clueless to their customers or pretend to have only elementary knowledge of key information about other suppliers and industry trends. Likeability This supplier parameter is placed near the end because it is to some degree a combination of some of the other parameters already discussed. It is retained as a separate entry because it is a surprisingly strong indicator of the happiness of a customer with a supplier. Suppliers who are well liked by their customers are usually retained by the customers for long periods of time even if the prices are not the very best. The categories of evaluation for this parameter are small, medium, and great. This is a more intuitive measurement, harder to quantify, but over the years it has been found to be the case that certain suppliers are well liked by many customers while other suppliers are highly disliked by many customers. Therefore customers should not be unabashed to rate a supplier on this quality and allow it to have some influence on their supplier selection. Sales Representative This is the sixteenth and last supplier evaluation parameter—and one of the most important parameters. It is listed last because it has been said that the sales representative is a microcosm of the supplier as a whole. Therefore, most of the evaluation items up to now should be applied again in reference to the sales representative to determine a rating for the sales representative. If the sales representative is technically strong, then the supplier as a whole may be technically strong. For example, can the sales representative draw the structure of the molecules he or she sells without looking them up and give nuanced details about hydration or gelation? If yes, the sales representative is technically strong. Is the sales representative easy to communicate with, responsive and caring, likeable? If so, it can be a good harbinger for the entire company. The

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ranking categories for sales representative are low competency, average, and strong asset. Supplier Evaluation Form The 16 items that have been described in this chapter are listed in the supplier evaluation form found below. This form can be copied and used by a customer as long as the source for it is listed. This will allow the third key, supplier qualities and benefits, to be elucidated for each potential supplier. The customer should first decide which of the three rating categories it decides will be acceptable for each of the last 14 parameters. Product quality is a yes/no evaluation. After the customer has decided whether to use a rank of one, two, or three for each of the fourteen rated categories, the customer should circle these acceptable ratings for each category. Then the customer should evaluate a supplier and place X’s below the ratings the supplier earns for each rating. If the supplier achieves a rating equal to or better than the minimum acceptable rating for each of the 14 categories, then this gives a good indication that the customer will be happy with the qualities of this supplier and the benefits the supplier offers to this customer. If the supplier falls below the mark on one or more qualities, then the customer will have to weigh the relative importance of the failed parameters and decide whether to still accept this supplier. In any case, suppliers are available who would meet any customer’s minimums for all 16 of the supplier-evaluation parameters. It is only a case of finding them.

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Supplier Evaluation Form 1.a. Customer Products 1.a. Price Quotes (FOB or DDP) 1.b. Other Products 1.b. Price Quotes (FOB or DDP) 1.c. Timing on Delivery 1.d. Categories: Single Gum 1.d. Categories: Multiple Gum 2.a. Quality in Lab Tests 2.b. Quality in Food Products 3. Certifications 4. Clarity of Communications 5. Ease of Communications 6. Logistical Capability 7. Technical Support 8. Applications Support 9. Ethics 10. Orientation 11. Caring/ Responsiveness 12. Future Adaptability 13. Innovativeness 14. Industry Knowledge 15. Likeability 16. Sales Representative

1st order Pure

Future orders Functional

Synergistic

Application

Pass

Fail

Pass

Fail

Not Available Terrible

In Process Acceptable

Available Excellent

Difficult

Good

Exceptional

Complicated None/Little None Poor Supplier Centric Little

Typical Limited Moderate Standard Middle Acceptable

Superior Expert Extensive Outstanding Customer Centric Unusual

Nonadaptable Impaired Clueless Small Low Competency

Adaptable Open to it Elementary Medium Average

Industry Leader Creative Strong Awareness Great Strong Asset

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Note: Italicized page locators indicate a figure/photo; tables are noted with a t. Acacia gum, 221 Acacia senegal trees, gum arabic from, 221, 223 Acacia seyal trees, gum arabic from, 221, 222 Acid degradation, processing conditions for bakery fillings and, 84 Acidity, low, salad dressings and, 31–32 Acids food-grade, 180t restructured foods and, 179–180 Actomyosin, meat proteins and, 37 Acylation, gellan gum and, 100 Adaptability, future, supplier evaluation and, 304–305 Added ingredient (AI) cured pork, carrageenan and, 40, 41 Additives, functional hydrocolloid blend and, 264–265 Adipic acid, restructured foods and, 180, 180t Aerated cr`eme fillings carboxymethylcellulose in, 94–95 foam stability and structure for, 68 Aerated yogurts, 148

Agar, 2 in bakery fillings, 99–100 commercial sources of, 99 flavor protection and, 216 heat treatment, bakery fillings and, 85 high cost of, 99 in low protein cheese, 163 temperature and, 3 Aging bath, for restructured pimiento strip formulation, 187t Air incorporation, avoiding, in salad dressings, 21 Albumin, flavor protection and, 216 Alginate gelation, 175 egg box model for, 175, 175 restructured foods and, 180–186 combination setting, 184–196 diffusion setting, 180–182 internal setting, 182–184 techniques, summary of, 213 Alginate gum, in pizza dough, 66 Alginate(s), 3 in acid pH gel system, 204t in bakery fillings, 90–92 propylene glycol alginate, 92 sodium alginate, 90–92

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Alginate(s), (Cont.) chemical structure differences with, 258t coacervation and, 235 concentration/viscosity curves for, 174 in cream fillings, 79 flavor stabilization and, 223 in muscle foods, 47–48 in restructured foods blackcurrants formulation, 192t brawn formulation, 198t carrot formulation, 196t cherry formulation, 209t chicken pieces formulation, 195t fish formulation, 190t internal set peach formulation, 206t meat burger formulation, 199t onion ring formulation, 189t pimiento strip formulation, 187t potato formulations, 203t salmon formulation, 195t source, chemistry, and properties of, 171–174 starch vs., in pie fillings, 12t Alginate solution, shear rate/viscosity curves for, 174 Alginate solution viscosity, degree of polymerization and its effect on, 173t Algin-based stabilizers, in frozen dairy desserts, 111 Alginic acid structure of, 172 structure of alginate segments containing, 171 Alkaline phosphates, addition of, to meat products, 36–37 Amidation, gelling properties of pectins and, 144

Amorphophallus spp., 95 Amorphous silicas, for flavor protection, 226 Amylopectin, 144, 217, 218 Amylose, 217, 218 high, components and properties of, 219t Analogue cheese, 163 Animal fat, availability of, across regions, 35 Anticompetitive practices, 281 Apparent viscosity, 258 Appearance grade differentiation and properties of, 262 gums substituted for starches and, 13 hydrocolloid functionality and, 7–8 Application hydrocolloid blend, 263t, 269, 270 Aqueous syneresis, gum levels and increase of, 7 Ascophyllum nodosum, M/G contents and ratios for alignates from, 172t Ash content, in carrageenan, 39 Asian companies, semicompetitive era of hydrocolloid history and, 249 Atkins diet, 105 Baked goods, instant, flavor coacervates and, 235 Bakery fillings cellulose derivatives in, 92–101 agar, 99–100 carboxymethylcellulose or cellulose gum, 94–95 carrageenan, 98–99 gellan gum, 100–101 konjac gum, 95–96 methylcellulose, 93–94

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Index microcrystalline cellulose, 95 xanthan gum, 96–98 commercial, processing and quality attributes of, 71–74t cream-based, 67 cr`eme, 78–80 formulation for, 79 procedure, 79–80 uses for, 78–79 egg-based, 67 factors affecting filling stabilization, 81–85 pH, 82–83 water activity, 81–82 water and solids content, 83–84 fat-based, 67 filling types, 69–70, 74–81 bakery cr`eme fillings, 78–80 custard filling, 76–77 fruit fillings, 69–70, 74–75 key lime pie filling, 78 lemon custard filling, 77–78 nut pie fillings, 78 pumpkin pie fillings, 75–76 toaster pastry and snack bar fillings, 80–81 fruit-based, 67 gums used in, 86–101 alginates, 90–92 guar gum, 87–88 locust bean gum, 86–87 pectin, 88–90 hydrocolloids in, 67–105 processing techniques and, 67 shelf life requirements and, 68 problems with, 101–105 boil out, 102–103 cracking, 101–102 emulsion separation, 104 freeze/thaw stability, 104 shrinkage, 103 sogginess of pastry, 104–105

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processing conditions, 84–85 available shear, 84–85 heat treatment, 85 proper balance of ingredients in, 68–69 research need, 105 storage time/conditions, 85 unstabilized and stabilized with locust bean gum, 101 Bakery products hydrocolloids in, 51–66 gums in bread, 53–55 gums in cake, 55–56 gums in cornbread muffins, 63–65 gums in egg pasta, 58–60 gums in flour tortillas, 56–58 gums in pancakes, 60–63 gums in pizza dough, 66 gums in reduced oil flour tortillas, 58 optional nonbaked fried cornbread, 65–66 Batch freezing, of frozen dessert mixes, 139 Batch pasteurization for frozen dessert mixes, 135 HTST pasteurization vs., 136–137 Bater, B., 39 Beef, internal set, 200, 200t. See also Meat; Muscle foods Beeswax, flavor protection and, 216 Beginnings era of hydrocolloid history, 245–246 pricing and, 274 Benchtop product development, hydrocolloids and, 13–14 Berries. See also Blackcurrants; Cherries solid and liquid-centered, 190–191 apparatus for, 191

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Bidding for accounts, 285 Bid pricing, advantages/disadvantages of, 283–284 Biopolymers, characterization of, on basis of degree of activity, 37t Blackcurrants solid and liquid-centered, 191 restructured formulation, 192t Blends, grade differentiation and, 262–263 Boil out, bakery fillings and, reasons for, 102–103 Bovine spongiform encephalopathy, gelatin concerns and, 147 Brabender extruder, 238 Bread basic formulation for, 54t gums in, 53–55, 54 preparation of, 54–55 Brie, 141 Brown seaweed alginates and alginic acid in, 171 M/G contents and ratios for alginates from, 172t worldwide harvesting of, 172 Burger-type products, restructured, 199–200 Buttermilk, cultured, 152–154 Buttermilk for baking, defined, 152 Buyouts, 284 Cake basic formulation for, 56t gums in, 55, 55 preparation of, 56 Calcium in restructured brawn formulation, 198t in restructured carrot formulation, 196t

in restructured chicken pieces formulation, 195t in restructured meat burger formulation, 199t in restructured potato formulations, 203t sequestrants and, 3 Calcium acetate, 5 Calcium alginate, 171, 175 Calcium carbonate, gel set time, solubility and, 48 Calcium chloride, 5 gel set time, solubility and, 48 Calcium salts acid pH system and choice of, 181 internal setting systems, 181t restructured foods and formula, molecular weight, solubility g/100mL, and pH, 177t types of, 176 Calcium sequestrants, restructured foods and, 178–179, 178t Calcium sulphate, in neutral pH internal setting systems, 192 Calcium sulphate dehydrate in internal set beef formulation, 200t in restructured egg formulation, 193t Calcium sulphate dihydrate, in neutral pH systems, 182 Calorie reduction, bakery fillings and, research needs, 105 Calories, limiting, hydrocolloid dressing stabilizers and, 24–25 Canada cheese standards in, 162 cottage cheese regulations in, 157 cream cheese regulations in, 158

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Index reduced fat sour creams in, 155 salad dressings marketed in, 19 sour cream regulations in, 154 Canned fruit fillings, 68 Canned pie fillings, processing and quality attributes of, 71–74t Capric acid, flavor protection and, 216 Carboxymethylcellulose in bakery fillings, 94–95 for flavor protection, 224t grades of, 94 structure of, 94 viscosity of at different concentrations in water viscosity, 260t range for, 260t Caring, supplier evaluation and, 303–304 Carnauba wax, flavor protection and, 216 Carpenter, R. N., 163 Carrageenan, 3 in application blends, 269 ash content in, 39 in bakery fillings, 98–99 benefits of, in meat products, 40 in buttermilk, 153t in cheeses, 162t, 163 chemical structure differences, 258t commercial sources of, 98 composition of, in meat processing, 38–39 cook yield as affected by concentration of, 42 in cottage cheese, 158t cracking prevention in bakery fillings with, 101 in cream fillings, 79 cured pork and, 40, 41 in custard filling, 77

315

derivation of functionality with, 41 for flavor protection, 224t for flavor protection and, 216 flavor stabilization and, 223 gelling characteristics of, 39–40 in ham, 45 heat treatment, bakery fillings and, 85 in meat products, 42–43 types of, 38 micrograph of, in cooked meat and fully hydrated in water, 41 moisture retention as affected by, 44 moisture to protein ratios and, 43 potassium chloride addition and effect on functionality of, 40t in process cheese products, 160, 161 process yields as affected by, 43 in Ricotta cheese, 159 in roast beef, 45–46 in seafood, 46–47 in sour cream, 155, 156t for stabilizing pumpkin pie, 76 structure of, 98 temperature and, 2 ten percent fat ice cream, with MCC/CMC stabilizer with, 122t transparent versions of, 7 in turkey breast, 44–45 types of, 98 in yogurt, 144 Carrageenan gum blend, in egg pasta, 59 Carrots, restructured, 196–187, 196t Carver Laboratory Press, 227 Casein, flavor protection and, 216 Cations dissolving hydrocolloids and influence of, 2–3

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Index

Cations (Cont.) gelling hydrocolloids and influence of, 4–5 gum functionality and control of, 13, 14 Caviar, artificial, 191 Cellulose abundance of, 92 derivatizing, 92–93 flavor protection and, 216 Cellulose derivatives in bakery fillings, 92–101 agar, 99–100 carboxymethylcellulose or cellulose gum, 94–95 carrageenan, 98–99 gellan gum, 100–101 konjac gum, 95–96 methylcellulose, 93–94 microcrystalline cellulose, 95 xanthan gum, 96–98 flavor stabilization and, 223 Cellulose gum in bakery fillings, 94–95 in coacervation, 235 in frozen dairy desserts, 111 Ceratonia siliqua, 86 Cereals, flavor coacervates and, 235 Certification supplier evaluation and, 293–294 three-point scale for, 294 CFR. See Code of Federal Regulations Cheddar cheese, 160, 161, 162 Cheese alternatives, 163 cheddar, 160, 161, 162 cold pack cheese food, 161, 162t cottage cheese, 156–157, 158t cream cheese and Neufchatel cheese, 158–159 imitation or analogue, 163

melting properties of, 160 Mozzarella, 161, 163 nacho cheese sauce, 161, 162t nonstandardized soft unripened, 159–160 pasteurized process spread, 161, 162t process products, 160–161 reduced fat, hydrocolloids in, 162 shredded, 163 slices on chill roll, 163 texture in, 141–142 varieties of, 161–164 Cheese sauces, 161 Cheese spread, pasteurized process, 142 Chelators, in salad dressings, 20 “Chemical” emulsifiers, in salad dressings, 21 Chemical structure grade differentiation and, 257–258 selected hdrocolloid chemical structure differences, 258t Cherries, restructured, 208–210 Chewing gum, flavor coacervates and, 235 Chicken pieces, restructured, 194–195 China competitive era of hydrocolloid history and, 251–253 as major hydrocolloid supplier, 251 Citrates, 3 Citric acid, 180t restructured foods and, 179 Citrus oils, extrusion process and, 234 Clarity of communications supplier evaluation and, 294–296 failure to keep logistical, technical service, and

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Index product quality commitments, 295 lack of experience and organizational skills, 295 rating, 296 spoken language skills, 294–295 written language skills, 295 Clean in place (CIP) system, hydrocolloids use and, 17 “Clean labeling,” 213 CMC. See Carboxymethylcellulose CMC gum, 52 in bread, 53 in cake, 55 in flour tortillas, 56 in pancakes, 60, 61 in pizza dough, 66 Coacervation defined, 234 process of, 234–235 Code of Federal Regulations, 219 Cold pack cheese food, 142 example formulas for, 162t Colloid mills, for making salad dressings, 21 Color(s) hydrocolloid functionality and, 7–8 maintain/impart, hydrocolloid dressing stabilizers and, 24 in salad dressings, 20 Combination setting for restructuring food using alginates, 184–186 acid conditions, 185–186, 186 neutral conditions, 185, 185 Combination setting–acid pH, 208–210 restructured cherries, 208–210 Combination setting–neutral pH, 206–208 restructured petfood chunks

317

formulation, 206–207 system for, 207–208 Commodity, defined, 253 Commodity era of hydrocolloid history, 253 pricing and, 274 Commodity-type ingredients, supplier selection and, 244 Communication with supplier clarity of, 294–296 ease of, 296 Competitive era of hydrocolloid history, 251–253 pricing and, 274 Compounded flavors, 216 Confidentiality agreements, 300 Conventional continuous freezing, of frozen dessert mix, 139 Cookie fillings, processing and quality attributes of, 73–74t Coprocessed combinations of hydrocolloids, 268 Corn common, components and properties of, 219t in meat products, 38 waxy, components and properties of, 219t Cornbread muffins, fried gums in, 63–65, 64 basic formulation, 64t preparation of, 64–65 Cornbread muffins, nonbaked fried gums in, 65, 65–66 preparation of, 66 Costs gums substituted for starches and, 13 multiple gums in formulation and, 10 viscosity grades of hydrocolloids and, 11

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Index

Cottage cheese, 142, 156–157 dressing formulas in, 157 dressing of nonfat and 4% fat, example formulas for, 158t dry curd, standard of identity for, 157 production of, 156–157 Course emulsion dressings, assembling salad dressings and, 22 Crab leg analogues, carrageenan and, 46 Cracking, of bakery fillings, 101, 101–102 Cream cheese, 142, 158–159 production methods for, 158–159 regulations for, 158 spreadable, 141, 159 Cream fillings, pH and, 83 Cross-linking, yogurt and, 145 Cryogenic freezing, frozen dessert mix, 140 Crystallization of fat, frozen dairy desserts and, 139 Cultured buttermilk, 152–154 low-fat and, example formulas for, 153t related products, 153–154 viscosity of, 153 Cultured dairy products. See also Frozen dairy desserts formulas for cultured low-fat buttermilk and cultured buttermilk, 153t formulas for nonfat, light, and regular sour cream, 156t formulation and processing parameters for drinkable and spoonable low-fat yogurts, 152t hydrocolloids in, 141–164 cottage cheese, 156–157

cream cheese and Neufchatel cheese, 158–159 cultured buttermilk, 152–154 drinkable yogurt and smoothies, 149–151 nonstandardized soft unripened cheeses, 159–160 other cheese varieties, 161–164 process cheeses products, 160–161 sour cream, 154–156 yogurt, 142–149 range of, 141 Cultures, contribution of, in cultured dairy products, 141 Curd manufacture, for cottage cheese, 157 Custard filling, 76–77 formulation for, 77 French, 76 preventing curdling in, 76 procedure, 77 Customer control, supplier control vs., composite factors in hydrocolloid pricing and, 276 Customers hydrocolloid pricing and what is known by, 279–280 not intentionally antagonizing suppliers and losing out on best prices, 284–286 single most important lesson of hydrocolloid history and, 275 supplier caring/responsiveness/respect toward, 303–304 supplier costs and influence of, 286 supplier gimmicks, price increases and, 280–281 technical support for, 297–299 Cyamopsis tetragonoloba, 87

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Index Dairy flavors, 216 DE. See Degree of estrification Deception, 301 Degree of estrification, pectin and, 89 Dessert yogurts, 148 Dextrose, for plating flavors, 223 Diabetes, bakery fillings and, research needs, 105 Dicalcium phosphates, 5 Diffusion set products, 186–192 advantages and disadvantages of, 192 restructured fish, 189–190 restructured onion rings, 188–189 restructured pimiento strip, 186–188 solid and liquid-centered cherries, 190–191 summary of settings, 191–192 Diffusion setting method for restructuring food using alginates, 180–182 in acid conditions, 181–182, 182 in neutral conditions, 180, 181 Diglycerides, flavor protection and, 216 Dipotassium phosphate, 3 Direct set processing, for sour cream, 156 Disodium phosphate, 178t, 179 Dispersing/hydrating equipment, frozen dairy desserts and dispersion of stabilizer without, 131 Dispersion funnel, frozen dairy desserts and dispersion of stabilizer, 132 Dissolving hydrocolloids cations and, 2–3 mesh size and, 1–2 temperature and, 2

319

Dixie agitated premix tank, 21 Doughnut fillings, 68, 78–80 Drake, M. A., 162 Dressing formulas, cottage cheese, 157 Drinkable yogurts, 148, 149–151 ingredient statements in, 151 low-fat, formulation and processing parameters for, 152t standards related to, 149 viscosities of, 149 Dry blending, of stabilizer for frozen dairy desserts, 131 Dry mix salad dressings, 19, 23 DSP. See Disodium phosphate Dusting problems, checking, hydrocolloids use and, 17 Ease of communication, supplier evaluation and, 296 Ecklonia cava, M/G contents and ratios for alignates from, 172t Economic conditions, meat products and, 35 EDTA. See Ethylenediaminetetraacetic acid Egg box model, for alginate gelation, 175, 175 Egg pasta basic formulation for, 60t gums in, 58, 58–59 preparation of, 60 Egg products, restructured, 193–194 Emulsifiers in buttermilk, 153t in cottage cheese, 158t in frozen dairy desserts appropriate use of, 111–112 overuse of, 113, 114

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Emulsifiers (Cont.) stabilizers used with, 109 typical use levels in, 113t in salad dressings, 20 in sour cream, 156t Emulsifying salts, in cheeses, 162t Emulsion separation, in bakery fillings, 104 English language skills, clarity of communications, supplier evaluation and, 294–295 Escherichia coli, 286 Essential oils, 215 Ethics, supplier evaluation and, 301–302 Ethylenediaminetetraacetic acid, in salad dressing, 21 European companies, semicompetitive era of hydrocolloid history and, 249, 250 Extracts, 215 Extruded novelty freezing, frozen dessert mix, 139 Extrusion for flavor encapsulation, 232–234 examples, 238–240 controlled release encapsulation compositions, 238 encapsulation composition, 240 encapsulation matrix composition, 238 fixation of volatiles in extruded glass substrates, 238 particulate flavor compositions and process to prepare same, 239 preparation of solid essential oil flavor composition, 238 process for preparation of granules for controlled

release of volatile compounds, 240 solid delivery systems for aroma ingredients, 239 solid essential oil flavor encapsulation, 238 Fat destabilization technique, for ice cream and frozen desserts, 117–118 Fat percent, for ice cream and frozen desserts, 115 Fats and fatty acids, flavor protection and, 216 Fenugreek gum, 52 in bread, 53 in cake, 55 in egg pasta, 58, 59 in flour tortillas, 56, 57 in fried cornbread muffins, 63 in nonbaked fried cornbread, 65 in pancakes, 60, 61 in reduced oil flour tortillas, 58 Fiber, dietary, in yogurt, 148 Fish, restructured, 189–190 Fish eggs, artificial, 191 Fisheyes, frozen desserts, defined, 129 Flavor encapsulation formulations, 237 spray-dried flavors, 237 spray-dried orange drink mix, 237 spray-dried orange oil formula, 237 Flavorings in salad dressings, 20 in yogurt, 142 Flavor matrix, correct choice of, 216 Flavor modifiers and enhancers, 216 Flavor(s) classification of, 215–216

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Index gums used for protection of, 224–225t hydrocolloid functionality and, 8 hydrocolloids and protection of, 216 web sites, 235, 236t hydrocolloids used for, 217–223 gums and modified gums, 221–223 modified starches, 217–219, 221 ingredient groups for protecting, 216 methods of stabilizing and protecting, 223–235 coacervation, 234–235 encapsulation through spray drying, 227–231 extrusion, 232–234 plating, 223, 226–227 stabilizing and protecting, 215–240 challenges related to, 215 Flour tortillas basic formulation for, 57t gums in, 56, 57 preparation of, 58 reduced oil, gums in, 58 Foam generation, frozen dairy desserts and, low fat/nonfat mixes, 128–129 Food applications defined, 299 semicompetitive era of hydrocolloid history and, 250 Food application tests, product quality and, 293 Food safety concerns, meat products and, 35 Formula descriptors, for ice cream and frozen desserts, 115–119

321

Formula development, for ice cream and frozen desserts, 119–120 Formula examples, for ice cream and frozen desserts, 120–127 Formulation, 195t process of, 196 France, yogurt standards in, 142 Free-fat method, fat destabilization technique vs., in ice cream and frozen desserts, 117 Free fat percent, for ice cream and frozen desserts, 117 Freeze/thaw stability, in bakery fillings, 104 Freezing methods, for high quality frozen desserts, 139–140 Freezing point, for ice cream and frozen desserts, 116 Freezing point depression index, 116 French custard filling, 76 French fries, 201 French salad dressing, 20 formulae/procedure for, 27–28 typical pourable, 27t Frozen dairy desserts. See also Cultured dairy products 5.71% fat no sugar added light ice cream galactomannan stabilizer with emulsifier, 124t formula descriptors, 115–119 destabilization %, 117-118 fat %, 115 free fat %, 117 freezing point, 116 milk solids %, 116 mix viscosity, 119 MSNF or NMS %, 116 natural serum solids %, 116 overrun %, 118 relative sweetness, 118 solid fat index, 118

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Index

Frozen dairy desserts (Cont.) soy solids not fat, 118 sucrose equivalence, 116–117 total solids %, 116 total soy solids, 119 whey solids %, 116 formula development, 119–120 formula examples, 120–127 freezing methods, 139–140 hydrocolloids in, 109–140 role of, 109–112 ingredient system suppliers for, 114 lactose-free soy frozen desserts, 126t limiting amount of unfrozen water in, 110 multicomponent systems, stability of price and supply, 114 processing, 127–140 checklist for dispersion and hydration of stabilizers in mixes, 134–140 dispersion of stabilizer in liquifier/blender, 133–134 dispersion of stabilizer using dispersion funnel, 132 dispersion of stabilizer using tri-blender, 132–133 dispersion of stabilizer without dispersing/hydrating equipment, 131 product handling problems, 110 representative levels of hydrocolloids and emulsifiers in categories of stabilizer blends, 112 sequencing of dry ingredient incorporation into water, milk, skim milk, soymilk, or condensed milk for, 129–130

soft serve side of, exception to normal aging process, 139 stabilizers used with emulsifiers in, 109 ten percent fat ice cream with MCC/CMC stabilizer with carrageenan, 122t total raw mix preparation for HTST system, idealized example, 130–131 12.25% fat low net carb ice cream, galactomannan stabilizer with emulsifier, 125t twelve percent fat ice cream with sodium alginate stabilizer, 121t two percent fat soft serve frozen yogurt, galactomannan stabilizer with emulsifier, 123t typical use levels for selected hydrocolloids and emulsifiers in, 113t Frozen dessert, use of term in text, 114 Frozen dessert mixes checklist for dispersion/hydration of stabilizers in, 134–135 freezing process, methods of, 139–140 pasteurization and homogenization methods and, 135 reconstituted, 139 Frozen pies and desserts, processing and quality attributes of, 73t Frozen yogurt, two percent fat soft serve, galactomannan stabilizer with emulsifier, 123t Fructose, for plating flavors, 223

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Index Fruit internal set–acid pH, system for, 205 internal set–neutral pH, system for, 197 in internal set peach formulation, 206t in restructured blackcurrants formulation, 192t in restructured cherry formulation, 209t Fruit fillings, 69–70, 74–75 favorite types of, 69 formulation for, 75 procedure for, 75 sugar-starch stabilizer systems and, 74 Fruit flavors, 216 Fruit pies fillings for, 68 restructured fruit in, 169 Fruit roll, 166 Functional blend hydrocolloid category, 263t, 264–267, 269 Future adaptability, supplier evaluation and, 304–305 Galactomannan-based stabilizer/emulsifier, in frozen dairy desserts, 112 Galactomannans in buttermilk, 153t in cheeses, 162t in cottage cheese, 157, 158t flavor protection and, 216 flavor stabilization and, 223 in sour cream, 156t Galactomannan stabilizer with emulsifier 5.71% fat no sugar added light ice cream with, 124t

323

12.25% fat low net carb ice cream with, 125t two percent fat soft serve frozen yogurt with, 123t Galactose content, of locust bean gum, 87 G-blocks, alginate in muscle foods and, 47 GDL. See Glucono-delta-lactone Gelatin in cheeses, 162t coacervation and, 234 commercial sources of, 146 for flavor protection, 216, 224t flavor stabilization and, 223 in frozen dairy desserts, 111 gel strengths of, 147 in sour cream, 155, 156t in spoonable yogurts, 146–147 temperature and, 3 in yogurt, 143 Gelidium agar, gel strength for, 99 Gellan gum, 3 acylation and, 100 in bakery fillings, 100–101 Gelling agents, restructured foods and, choice of, 170 Gelling characteristics, of carrageenan, 39–40 Gelling gums, bakery fillings and, 85 Gelling hydrocolloids cations and, 4–5 temperature and, 3–4 Gel properties, grade differentiation and, 259–261 Gel set time, alginate and, control of, 48 Gel strength, 260, 270 upper and lower levels in specifications for, 261 verification of, 292

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Index

Genetically modified organisms bakery fillings and, 86 gum acacia product free of, 223 Glossiness in foods, gums and, 8 Glucono-delta-lactone, 48 restructured foods and, 180, 180t Gluluronic acid, 257 Glycemic index, bakery fillings and, research needs, 105 GMOs. See Genetically modified organisms GMP. See Good manufacturing practices GMP type certifications, as standard for hydrocolloids manufacturers, 254 Good manufacturing practices, 286, 293 Gossip, industry knowledge and, 306 Gracilaria agar, gel strength for, 99 Grade differentiation key items used in, 257–263 blends, 262–263 chemical structure, 257–258 gel properties, 259–261 mesh size of particles, 261–262 organoleptic and appearance properties, 262 special stabilities, 262 viscosity, 258–259 Grades hydrocolloid functionality and basis of, 256–257 specific, hydrocolloids divided into, 255–256 Granola-type bars, restructured fruit in, 169 GRAS approval future of pricing and, 288 gum acacia product, 223 restructured foods and, 213 Greek-style yogurt, 149

Guar gum, 2, 52, 87–88 in application blends, 269 in bakery fillings, 87–88 benefits/liabilities in salad dressings, 27 in cake, 55 in egg pasta, 58, 59 for flavor protection, 224t in fried cornbread muffins, 63 in frozen dairy desserts, 111 minor drawback with, 88 in nonbaked fried cornbread, 65 in nut pie fillings, 78 in pizza dough, 66 processing conditions for bakery fillings and, 84 in reduced oil flour tortillas, 58 in Ricotta cheese, 159 sale of, as commodity, 254 in sour cream, 155 special stabilities, grade differentiation and, 262 synergistic hydrocolloid blends and, 267, 268 in toaster pastry and snack bar fillings, 80 usefulness and popularity of, 88 viscosity and, 258 at different concentrations in water viscosity, 260t range for, 260t Gum arabic, 218 coacervation and, 234 for flavor encapsulation, 229 for flavor protection, 216, 221, 224t grades of, 222 lemon oil encapsulated in, photomicrograph, 232 manufacture of, 222 modified, for flavor protection, 224t

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Index molecular weight, 221–222 sale of, as commodity, 254 viscosity of, at various percentages of solids, OSAn starch vs., 220 Gums in bakery fillings, 86–92 alginates, 90–92 guar gum, 87–88 locust bean gum, 86–87 pectin, 88–90 in bakery products beneficial properties of, 51–52 stand-alone or in combination, 52–53 in bread, 53–55 in cake, 55–56 in cornbread muffins, 63–65 in egg pasta, 58–60 in flour tortillas, 56–58 functionality of, benchtop product development and, 13–14 glossiness and sheen in foods with, 8 hydrocolloids, scale-up to plant production and incorporation of, 15 modified gums and, flavor protection with, 221–223 in nonbaked fried cornbread, 65–66 in pancakes, 60–63 in pizza dough, 66 in reduced oil flour tortillas, 58 transparent versions of, 7 variation in ratios, 53 Gum tragacanth, hydrocolloid dressing stabilizers and, 23 Halal certification, gelatin concerns and, 146

325

Ham carrageenan in, 45 cured, suggested formulations for, 46t Heating benchtop product development and, 13–14 dissolving hydrocolloids and, 2 Heat treatment, bakery fillings and, 85 HFCS. See High fructose corn syrup High agitation mixing, small particle size hydrocolloids and, 1 High fructose corn syrup, fruit fillings and, 70 High temperature short time systems frozen dairy desserts and, 128 pasteurization for frozen dessert mixes and, 136 total raw mix preparation for, idealized example, 130–131 Hispanic style cheese, 159 HM pectins, gelation of, 89–90 Holding, hydrocolloids, scale-up to plant production and, 15 Homogenization for frozen dessert mixes, 135, 137–138 for sour cream, 154 Hoof and mouth disease, gelatin concerns and, 146 HTST systems. See High temperature short time systems Hydrocolloid dressing stabilizers, typical functions of, 23–25 Hydrocolloid functionality color or appearance, 7–8 effects on flavor, 8 stabilization, 6–7 texture, 5–6

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Index

Hydrocolloid history beginnings era of, 245–246 commodity era of, 253 competitive era of, 251–253 monopoly era of, 246–249 pricing and, 274–275 semicompetitive era of, 249–251 stages of, caveats, 245 Hydrocolloid product categories, 263–269 application blends, 263t, 269, 270 functional blends, 263t, 264–267, 269 pure hydrocolloid, 263–264, 263t summary, 269–270 synergistic blends, 263t, 267–268, 269–270 Hydrocolloids. See also Purchasing hydrocolloids; Suppliers of hydrocolloids categories of, 263t dissolving cations and, 2–3 mesh size and, 1–2 temperature and, 2 fifteen practical tips related to, 1–17 flavor protection and, 216 functionality of color or appearance and, 7–8 flavor and, 8 stabilization and, 6–7 texture and, 5–6 gelling cations and, 4–5 temperature and, 3–4 procurement, difficulties in, 243–244 product selection: three levels of classification of, 263, 263t salad dressings, type and level of, 32–33

small particle size, reducing lumping in, 1–2 successful purchasing of, three keys to, 244 typical viscosity ranges of, 260t using basic tests, 9 benchtop product development, 13–14 plant troubleshooting, 16–17 scale-up to plant production, 15–16 single gum vs. multiple gums, 9–11 substitution of gums for starch, 12–13 Hydrocolloid stabilizers hydrating, in assembling salad dressings, 22 in salad dressings, 20 Hydroxypropylcellulose, for flavor protection, 225t Hydroxypropylmethylcellulose for flavor protection, 225t gel, in cheese mixture, 163 Ice cream light, 5.7% fat no sugar added, galactomannan stabilizer with emulsifier, 124t restructured fruit in, 169 ten % fat, with MCC/CMC stabilizer with carrageenan, 122t 12.25 % fat low net carb, galactomannan stabilizer with emulsifier, 125t twelve % fat, with sodium alginate stabilizer, 121t use of term in text, 114

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Index Imitation cheese, 163 Individually quick frozen (IQF) forms, of fruit fillings, 69 Individual quick frozen treatment, restructured food and, 169 Industry knowledge, supplier evaluation and, 306–307 Ingredient system suppliers, for frozen dairy desserts, 114 Innovativeness, supplier evaluation and, 305–306 Insoluble calcium salts, 176 Internal set beef formulation for, 200t process of, 200 Internal set products–acid pH, 203–206 acid pH model gel system, 204t internal set peach formulation, 205–206, 206t process for, 204–205 Internal set products–neutral pH, 192–203 burger-type products, 199–200 internal set beef, 200 petfood brawn, 198–199 potato products, 201–203 restructured chicken pieces, 194–195 restructured egg products, 193–194 restructured meat, 200–201 restructured meat products, 197 restructured neutral pH vegetables, 196–197 restructured salmon, 195–196 Internal setting process for restructuring food using alginates, 182–183 in acid conditions, 184, 184 in neutral conditions, 182–184, 183

327

International organization for standardization, 286 certifications as standard for hydrocolloids manufacturers, 254 supplier evaluation and, 293, 294 International Specialty Products restructured egg products, 193–194 Restructured Meat System # 2, 213 Inulin, in yogurt, 148 Iota, in meat products, 38 IQF treatment. See Individual quick frozen treatment ISO. See International organization for standardization ISP. See International Specialty Products Italian salad dressing low-calorie formulae/procedure for, 30 typical, 30t separating type formulae/procedure for, 29 typical, 29t Jacobson, M. R., 163 Jansson, P. E., 96 Joint supplier gimmicks, profits sustained with, 281–282 Kappa-carrageenan, 271 grade strength and, 260 leaving off specification for, 249 in meat products, 38 PSE meat products and, 41 temperature and, 3, 4 in yogurt, 144 Kefir, 154 Key lime pie filling, 78

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Konjac/konjac gum, 47, 52–53 in bakery fillings, 95–96 boilout in bakery fillings and, 103 in bread, 53 in cake, 55 in custard fillings, 77 in egg pasta, 58, 59 in flour tortillas, 57 in fried cornbread muffins, 63 in muscle foods, 43–44 in nonbaked fried cornbread, 65 in nut pie fillings, 78 in pancakes, 60 in pizza dough, 66 processing conditions for bakery fillings and, 84 in reduced oil flour tortillas, 58 for stabilizing pumpkin pie, 76 viscosity and, 258 at different concentrations in water viscosity, 260t range for, 260t Kosher certification gelatin concerns and, 146 supplier evaluation and, 293 Lactic acid bacteria, 141 Lactose, for plating flavors, 223 Lactose-free soy frozen desserts, 126t Laminaria digitata, M/G contents and ratios for alignates from, 172t Laminaria hyperborrea (stipes), M/G contents and ratios for alignates from, 172t Language barriers, supplier evaluation and, 294–295 Large curd cottage cheese, 156 Lauric acid, flavor protection and, 216 Layoffs, 284, 303

LBG. See Locust bean gum L-carrageenan, temperature and, 3, 4. See also Carrageenan; Kappa–carrageenan Leader companies, future adaptability of, 305 Lemon custard filling, 77–78 Lemon flavor, plating of, in Pure-Dent B730 vs. with maltodextrin and corn syrup solids, 227 Lemon oil encapsulated in gum arabic, photomicrograph, 232 encapsulation of, in dextrinized starch, photomicrograph, 233 Likeability, supplier evaluation and, 307–308 Liquid frozen dessert mixes, homogeneous, processing of, 127–128 Liquid separation, yogurt and, 151 Liquifier, frozen dairy desserts and, dispersion of stabilizer, 133–134 Llanto, M. G., 46 Locust bean gum, 2 in application blends, 269 in bakery fillings, 86–87 in cottage cheese, 157 in cream cheese, 159 in custard filling, 77 for flavor protection, 224t in frozen dairy desserts, 111 in nut pie fillings, 78 preventing cracking in bakery fillings with, 101 processing conditions for bakery fillings and, 84 pumpkin pie filling stabilized with, 76 in Ricotta cheese, 159

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Index in sour cream, 155 stabilized filling with, 101 synergy with xanthan gum, 87 in toaster pastry and snack bar fillings, 80 viscosity and, 258 range for, 260t in yogurt, 144 Logistical commitments, suppliers failing to keep, 295 Logistical facility, supplier evaluation and, 297 Low acyl gellan, uses for, 100 Low draw, modified continuous freezing, of frozen dessert mix, 139 Lumps, frozen desserts, defined, 129 Macrocystis pyrifera, M/G contents and ratios for alignates from, 172t Madison Ice Cream Short Course Manual, 126 Maekaji, K., 96 Maltodextrins extrusion for flavor encapsulation and, 232 flavor protection and, 216 Mannuronic acid, 257 Manucol JKT alginate blend, in restructured egg products, 193t, 194 Market prices, for hydrocolloids, trusted suppliers and, 243 Match products, semicompetitive era of hydrocolloid history and, 250 Mayonnaise, real, 20 Mayonnaise-type spoonable salad dressing, 31t formulae/procedure for, 31–32

329

M-blocks, alginate in muscle foods and, 47 MCC. See Microcrystalline cellulose Meat. See also Muscle foods cooked, micrograph of carrageenan in, 41 restructured, 197, 200–201 Meat formulas, differences in, over time and across regions, 35 Melton, L. D., 96 Mesh hydrocolloids, dry mix salad dressings and, 23 Mesh size, 270 dissolving hydrocolloids and influence of, 1–2 for hydrocolloids in salad dressings, 32 of particles, grade differentiation and, 261–262 Methylcellulose in bakery fillings, 93–94 gelling property, 93 preventing cracking in bakery fillings with, 102 synergistic hydrocolloid blends and, 267 viscosity grades, 93 Methyl ethyl cellulose, for flavor protection, 225t Meuser, F., 226 M/G contents and ratios, for alginates from different brown seaweed species, 172t Microcrystalline cellulose, 32 in bakery fillings, 95 benefits/liabilities of, in salad dressings, 26 in frozen dairy desserts, 111 hydrocolloid dressing stabilizers and, 23, 25 in lowfat cheese, 162 Microsoft Excel, 126

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Index

Milk solids percent, for ice cream and frozen desserts, 116 Mills, E. W., 40 Mixing colloids, benchtop product development and, 13 Mix viscosity, for ice cream and frozen desserts, 119 Modified food starches benefits/liabilities of, in salad dressings, 26 for flavor protection, 217–219, 217t, 221 low cost of, 12 pumpkin pie stabilizing and, 76 in sour cream, 155 Moisture migration, in bakery fillings, delaying, 105 Moisture retention, in meat, 36 Monoglycerides, flavor protection and, 216 Monopoly era of hydrocolloid history, 246–249 pricing and, 274 Monosodium glutamate, restructured foods and, 169 Motzer, E. A., 41 Mousse process, frozen dessert mix, 140 Mouthfeel, hydrocolloid dressing stabilizers and, 25 Mozzarella cheese, 161 alternatives for, 163 low-fat, 142 MSG. See Monosodium glutamate MSNF percent, for ice cream and frozen desserts, 116 Multiple gums, single gums vs., hydrocolloids and, 9–11 Muscle foods hydrocolloids in, 35–48 alginate, 47–48 carrageenan and, 38–43

characterization of biopolymers on basis of degree of activity, 37t ham, 45 konjac, 43–44 moisture retention and, 36 postpackaging pasteurization and, 35 roast beef, 45–46 salt and chloride and, 36 seafood, 46–47 starches and, 37–38 synergies, 44 turkey breast, 44–45 potassium chloride and functionality of carrageenan in, 40t synergies between hydrocolloids in, 44 Mushrooms, restructured, 197 Nacho cheese sauces, 161 example formulas for, 162t National Register Company, 234 “Natural” emulsifiers, in salad dressings, 21 Natural serum solids percent, for ice cream and frozen desserts, 116 NCR. See No-carbon-required paper Neufchatel cheese, 158–159 production methods for, 158–159 regulations for, 158 Niche suppliers, pricing and, 288 Niemann, C., 226 NMS percent, for ice cream and frozen desserts, 116 No-carbon-required paper, 234 n-octenyl succinic anhydride, 218 dextrinized effect of addition of maltodextrin on particle size

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Index of lemon emulsion stabilized by, 230 emulsifying properties of, 221 esterification of starch and, 220 flavor encapsulation and, 229 flavor protection, choice of, 221 stability of lemon oil in, with fiber and maltodextrin compared with pure OSAn starch, 231 viscosity of gum arabic vs., 220 Nut pie fillings, 78 Nutritionally modified yogurts, 148 Obesity control, bakery fillings and, research needs, 105 Oil, in salad dressings, 20 Oleoresins, 215 Onion rings, restructured, 188–189 Opacity hydrocolloid functionality and, 7 increased air incorporation and, 8 Orange drink mix, spray-dried formula for, 237 Orange oil formula, spray-dried, 237 Organic acid, meat product food safety and, 35 Organoleptic properties, grade differentiation and, 262 Orientation of supplier, supplier evaluation and, 302–303 OSAn. See n-octenyl succinic anhydride Overrun percent index, for ice cream and frozen desserts, 118 Overstabilization, 6–7 Packaging, hydrocolloids, scale-up to plant production and, 15 Pale, soft, and exudative (PSE) raw material, kappa-carrageenan and, 41

331

Palmitic acid, flavor protection and, 216 Pancakes gums in, 60–63, 61, 62 basic formulation for, 62t preparation of, 63 Parmesan cheese, 141 Particle size flavor encapsulation and, 229, 229–230 for hydrocolloids in salad dressings, 32 solubility and, 1 Pasteurization for frozen dessert mixes, 135 postpackaging, meat products and, 35 for sour cream, 154 for yogurt, 143 Pasteurized process cheese products, 160 Pasteurized process cheese spread, example formulas for, 162t Peach formulation internal set, 205–206 formulation for, 206t process for, 205–206 Pectin, 3, 88–90 in bakery fillings, 89–90 chemical structure differences, 258t flavor protection and, 216 galacturonic acid in, 89 gelling property of, 89 heat treatment, bakery fillings and, 85 production of, 88 in yogurt, 144, 150, 151 Penn State’s Ice Cream Short Course Manual, 126

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Index

Petfood brawn, restructured, 198–199 Petfood chunks, restructured, 206–208 PGA. See Propylene glycol alginate pH bakery filling stabilization and, 82–83 for cultured buttermilk, 153 of yogurt, 143, 145 Phage, yogurt and, 148 Phosphate, addition of, to meat products, 36, 37 Pie fillings, alginate vs. starch in, 12t Pimiento strips, restructured, 168–169, 186–188 Pizza dough, gums in, 66 Plant production, hydrocolloids and scale-up to, 15–16 Plant troubleshooting, hydrocolloids and, 16–17 Plating defined, 223 of flavors, 223, 226–227 Pollack, surimi and, 46 Polydextrose, 74 Polyethylene glycol, flavor protection and, 216 Polysaccharides, flavor protection and, 216 Pommes noisettes, 201 Popsicles, restructured fruit in, 169 Pork, pale, soft, and exudative (PSE) raw material in, 41 Potassium alginate, for flavor protection, 225t Potassium chloride functional blends and, 265 functionality of carrageenan and addition of, 40t in meat products, 39

Potato components and properties of, 219t in meat products, 38 Potato products, restructured, 201–203 Pourable salad dressings, 19 Prahbu, G. A., 40 Preblending, small particle size hydrocolloids and, 1, 2 Premix tanks, assembling salad dressings and, 21, 22 Price quotes, asking for, 285 Prices and pricing best, how customers can avoid annoying suppliers and lose out on, 284–286 bid, advantages/disadvantages of, 283–284 functional blends and, 266 quote, advantages/disadvantages of, 282 spot, advantages/disadvantages of, 282–283 synergistic hydrocolloid blends and, 268 Probiotic cultures, in yogurt, 148 Process cheese products, 160–161 Processing, for ice cream and frozen desserts, 127–131 Processing conditions in bakery fillings, 84–85 available shear, 84–85 heat treatment, 85 Product categories and types supplier evaluation and, 290–292 sale of many gums, a few gums, or one gum, 291–292 sale of other related types of hydrocolloids, 291 sales of other hydrocolloid product categories, 290

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Index Product grades, summary, 270–271 Product key selection, hydrocolloid history applied to, 255 Product quality supplier evaluation and food application tests, 293 testing for, 292–293 verification of viscosity and gel strength, 292 Product quality commitments, suppliers failing to keep, 295 Product selection, correct, importance of, 255–256 Profit mentality, high, of hydrocolloid suppliers, 275–276 Profits joint supplier gimmicks and, 281–282 supplier gimmicks and, 280–281 Propylene glycol alginate, 258, 288 in bakery fillings, 92 benefits/liabilities of, in salad dressings, 25–26 hydrocolloid dressing stabilizers and, 23 in nut pie fillings, 78 Protein aggregation, controlling, in acid yogurts and smoothies, 150 Proteins flavor protection and, 216 moisture retention in meat and, 36 PSE raw material. See Pale, soft, and exudative (PSE) raw material Pseudogels, 52 Pseudoplasticity, of sodium alginate solutions, 173 Pumpkin pie fillings, 75–76 Purchasing hydrocolloids applying hydrocolloid history to product grade selection, 255

333 basis of grades: hydrocolloid functionality, 256–257 correct product selection, importance of, 255–256 difficulties with, 243–244 grade differentiation blends, 262–263 chemical structure, 257–258 gel properties, 259–261 mesh size of particles, 261–262 organoleptic and appearance properties, 262 special stabilities, 262 viscosity, 258–259 hydrocolloid functionality, 256–257 hydrocolloid history beginnings era of hydrocolloid history, 245–246 commodity era of hydrocolloid history, 253–254 competitive era of hydrocolloid history, 251–253 first purchasing key, hydrocolloid history applied to, 255 monopoly era of hydrocolloid history, 246–249 semicompetitive era of hydrocolloid history, 249–251 stages of, 245 pricing, 273–289 avoiding price increases from suppliers and gaining price decreases from suppliers, 287–288 customer control vs. supplier control of composite factors in, 276–277 customer factors influencing supplier costs, 286

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pricing (Cont.) customer knowledge, 279–280 customers not antagonizing suppliers and forfeiting best prices, 284–286 future of, 288–289 high profit mentality of suppliers, 275–276 hydrocolloid history and, 274–275 joint supplier gimmicks for sustaining high profits, 281–282 spot, quote, and bid: advantages/disadvantages, 282–284 supplier gimmicks for sustaining high prices/profits, 280–281 true market, 277–279 product categories application blend, 269 functional hydrocolloid blend, 263t, 264–267 pure hydrocolloid, 263–264, 263t synergistic hydrocolloid blend, 267–268 product grades specific, 255–256 summary, 270–271 product selection: levels of hydrocolloid classification, 263 successful, three keys to, 244 supplier screening, 289–290 Pure-Dent B730 lemon flavor plated in, vs. with maltodextrin and corn syrup solids, 227

photomicrograph of starch granules, 226 Pure hydrocolloid category, 263–264, 263t QA personnel, supplier technical support and, 298 QA tests, product quality and, 293 Quality, multiple gums in formulation and, 10 Quality assurance data, hydrocolloid usage and, 16–17 Queso blanco, 141 Quiescently frozen novelty, frozen dessert mix, 139 Quote prices, advantages/disadvantages of, 282 Raffinose, 119 Ratings for applications support by supplier, 299–300 for caring/responsiveness/respect shown by supplier, 304 for clarity of communication with supplier, 296 for ease of communications with supplier, 296 for ethics of supplier, 301–302 for future adaptability of supplier, 304 for industry knowledge by supplier, 307 for innovativeness of supplier, 305 for logistical facility with supplier, 297 for sales representative, 307–308 for technical support by supplier, 297–299 Raw frozen dessert mixes, no lump rule for, 127–128

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Index Raw material costs, supplier gimmicks, price increases and, 280 Raw material price fluctuations, supplier stocking habits and, 276–277 Reconstituted frozen dessert mix, 139 Rees, D. A., 175 Relative sweetness index, for ice cream and frozen desserts, 118 Rennet casein, in cheese, 163 Research and development (R&D) applications support and, 300 innovativeness and, 277 price information and, 292 product categories and types and, 291, 292 supplier technical support and, 298 Respect, supplier evaluation and, 303–304 Responsiveness, supplier evaluation and, 303–304 Restructured burger-type products, 199–200 formulation for, 199t process for, 199–200 Restructured cherries, 208–210 formulation for, 209t process for alginate phase, 209–210 puree phase, 210 production of, 208 Restructured chicken pieces, 194–195 formulation for, 195t process for, 194–195 Restructured egg products, 193–194 features of, 193–194 formulation for, 193t process for, 194

335

Restructured fish, 189–190 diffusion setting and, 181, 189–190 formulation for, 190t Restructured foods acids and, 179–180, 180t act of restructuring, 168 alginate gelation and, 175–186 combination setting, 184–186 diffusion setting, 180–182 egg box model for, 175 internal setting, 182–184 summary of techniques, 213 in ancient history, 166 calcium salts and, 176, 177t, 178 calcium sequestrants and, 178–179, 178t combination setting–acid pH, 208–210 restructured cherries, 208–210 combination setting–neutral pH-208, 206 restructured petfood chunks formulation, 206–207 system for combination set petfood chunks, 207–208 cost benefits with, 210–213 opportunities, 212 strengths, 211 SWOT analysis, 211t threats, 213 weaknesses, 212 definitions related to, 165, 166–167 dehydration/rehydration of, 169 diffusion set products, 186–192 restructured fish, 189–190 restructured onion rings, 188–189, 189t restructured pimiento strip, 186–188

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Restructured foods (Cont.) solid and liquid-centered berries, 190–192, 191, 192t examples of, 167, 167t gelling system for, 167 goal of, 165 hydrocolloids in, 165–213 alginates: source, chemistry, and properties, 171–174 gelling agent choices, 170 processing process, parts of, 170 internal set products–acid pH, 203–206 acid pH model gel system, 203–205, 204t internal set peach formulation, 205–206, 206t internal set products–neutral pH, 192–203 burger-type products, 199–200, 199t internal set beef, 200 petfood brawn, 198–199, 198t potato products, 201–203, 202t, 203t restructured chicken pieces, 194–195 restructured egg products, 193–194 restructured meat products, 197, 200–201, 201t restructured neutral pH vegetables, 196–197 restructured salmon, 195–196 Restructured meat products, 197 formulation for, 201t Restructured neutral pH vegetables, 196–197 formulation for, 196t process for, 197 Restructured onion rings

formulation for, 189t making, 188–189 Restructured petfood brawn formulation for, 198t process for, 198–199 Restructured petfood chunks combination set, 206–208 system for, 207, 207–208 Restructured pimiento strip, 186–188 formulation for, 187t setting bath for, 187–188 Restructured potato products, 201–203 from different ingredients, 202 formulations for, 203t novel, 201 process for, 202–203 Restructured salmon, 195–196 Restructuring process, parts of, 170 Reversible sequestrants, 179 Rheology desired, obtaining for salad dressings, 32–33 hydrocolloid dressing stabilizers and, 24 Rice, waxy, components and properties of, 219t Rice starch, in meat products, 38 Ricotta cheese, 159 Roast beef, carrageenan in, 45–46 Romano cheese, 141 Sahardi, 166 Salad dressings hydrocolloids in, 19–33 assembling, 21–23 determining type and level of, 32–33 major dressing stabilizers– benefits/liabilities, 25–32

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Index typical functions of hydrocolloid dressing stabilizers, 23–25 marketing of, in U.S. and Canada, 19 structure and texture and, 256 top 12 popular flavors of, 20 typical dressing formulae, 27t typical equipment for making, 21 typical ingredients in, 20–21 Sales representative, supplier evaluation and, 307–308 Salmon, restructured, 195–196 Salmonella, 286 Salt(s) addition of, to meat products, 36, 37 alginate, 171 in salad dressings, 20 Sample submissions, respectful treatment of, 285 Sauces, instant, flavor coacervates and, 235 Savory flavors, 215 Scale-up to plant production, hydrocolloids use and, 15–16 Scanning electron microscopy, evaluating flavor particles after spray drying with, 230–231 Schallow, S. M., 163 Seafood, imitation products, carrageenan in, 46–47 Seaweeds, carrageenan extracted from, 98 Sebranek, J. G., 40 SEM. See Scanning electron microscopy Semicompetitive era of hydrocolloid history, 249–251 pricing and, 274 Semi-gelled structures, 4

337

Separating dressings, assembling salad dressings and, 22 Separation control/prevention, hydrocolloid dressing stabilizers and, 24 Sequestrants, dissolving hydrocolloids and, 3 Serum separation, yogurt and, 151 Setting bath for restructured blackcurrants formulation, 192t for restructured cherry formulation, 209t for restructured fish formulation, 190t for restructured onion ring formulation, 189t for restructured pimiento strip formulation, 187t Shear bakery fillings and, 84–85 postculture, yogurt and, 147 sodium alginate solutions and, 173 Sheen in foods, gums and, 8 Shelf life for bakery fillings, 68 for ice cream and frozen desserts, monitoring, 120 for restructured foods, 168 Shellac, flavor protection and, 216 Shipping costs, synergistic hydrocolloid blends and, 268 Shrimp analogues, carrageenan and, 46 Shrinkage, in bakery fillings, 103 Silicas, for flavor protection, 226 Single gums, multiple gums vs., 9–11 Small curd cottage cheese, 157 Smoothies, 149–151 formulation and processing for, 151 structure and texture of, 256

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Snack bar fillings, 80–81 Snack cakes, processing and quality attributes of, 71–72t Sodium alginate, 3, 170, 270 in bakery fillings, 90–92 cations and, 5 chemical structure, grade differentiation and, 257 commercial availability of, 173 commercial sources of, 90 for flavor protection, 225t gelation of, 91 in internal set beef formulation, 200t in muscle foods, 47, 48 in restructured meat formulation, 201t for restructuring, 168 solutions pseudoplasticity of, 173 shear and, 173–174 stability of, at high baking temperatures, 91 synergistic hydrocolloid blends and, 267 transparent versions of, 7 viscosity and at different concentrations in water viscosity, 260t grades of, 91 range for, 260t Sodium alginate stabilizer, twelve percent fat ice cream with, 121t Sodium carboxymethyl cellulose, 3 Sodium caseinate, cook yield of, carrageenan vs., 40 Sodium chloride in buttermilk, 153t for plating flavors, 223

Sodium citrate in buttermilk, 153t in sour cream, 156t Sodium hexametaphosphate, 3, 178t, 179, 183 Sodium phosphates, in sour cream, 156t Sodium polymetaphosphate (Calgon), 179 Soft cheeses, 159–160 Softening, water activity in bakery fillings and, 82 Sogginess of bakery fillings, 104–105 water activity in bakery fillings and, 82 Solid fat index, for ice cream and frozen desserts, 118 Solids content, in bakery fillings, 83–84 Solubility gel set time and, 48 particle or mesh size and, 1 Soluble calcium salts, 176 Soups, instant, flavor coacervates and, 235 Sour cream, 154–156 direct set processing for, 156 nonfat, light, and regular, example formulas for, 156t production of, 154 reduced fat, 155–156 shear and, 155 standards of identity for, 154 South America, semicompetitive era of hydrocolloid history and, 249 Soy, flavor protection and, 216 Soy-based frozen desserts, stabilizer/emulsifier use in, 127

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Index Soy frozen desserts, lactose-free, 126t Soy solids not fat percent, for ice cream and frozen desserts, 118 Special stabilities, grade differentiation and, 262 Specifications for grades, commodity era of hydrocolloid history and, 254 Sphyngomonas elodea, 100 Spices, in salad dressings, 20 Spoonable salad dressings, 19 assembling salad dressings and, 22–23 formulae/procedure for, 28–29 typical, 28t Spoonable yogurts ingredient statements in, 151 low-fat, formulation and processing parameters for, 152t Spot pricing, advantages/disadvantages of, 282–283 Spray-dried flavors, National Starch website, 237 Spray-dried orange drink mix formulation, 237 Spray-dried orange oil formulation, 237 Spray drying, flavor encapsulation through, 227–231, 228 Stability grades, hydrocolloid functionality and, 256 gums substituted for starches and, 13 Stabilization of cultured dairy products, 141 hydrocolloid functionality and, 6–7

339

Stabilizers alternative, in yogurt, 143–144 frozen dairy desserts, emulsifiers used with, 109 frozen dairy desserts and checklist for dispersion/hydration of, in frozen dessert mixes, 134–135 dispersion of, in liquifier/blender, 133–134 dispersion of, using dispersion funnel, 132 dispersion of, using Tri-Blender, 132–133 dispersion of, without dispersing/hydrating equipment, 131 in fruit fillings, 70–74 in pumpkin pie fillings, 76 in yogurt, 142 Stable, pourable emulsions, for assembling salad dressings, 21–22 Stachyose, 119 Stainless steel equipment, for making salad dressings, 21 “Standardized” blends, 265 Standardized-type grades, monopoly era of hydrocolloid history and, 247, 248–249 Standard of identity, for restructured foods, 166, 167–168 Starch cross-linking, effects of shear and, on yogurt white mass viscosity, 146 Starches alginate vs., in pie fillings, 12t in cheese, 163 components and properties of, 219t

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Starches (Cont.) dextrinized, lemon oil encapsulated in, 233 as flavor carrier, 226 flavor protection and, 216 flavor suppression and, 8 hydrocolloids and substitution of gums for, 12–13 in meat products, 37–38 modified extrusion for flavor encapsulation and, 232 for flavor protection, 217–219, 221 low cost of, 12 in yogurt, 143–144, 145 Starch polymers, amylose and amylopectin, 217, 218 Stearic acids, flavor protection and, 216 Stirred yogurts, 143 Stoke’s law, 150 Storage time/conditions, for bakery fillings, 85 Strained yogurt, 149 Strawberries, in yogurt in North America, 142 “Stretch marks,” in turkey breast, 45 Structure, grades, hydrocolloid functionality and, 256 Structured food, defined, 166 Substitute cheese, 163 Substitution, yogurt and, 145 Sucrose, for plating flavors, 223 Sucrose equivalence, for ice cream and frozen desserts, 116–117 Sugar in fruit fillings, 70 protein content in yogurt and, 150–151 Sugar-starch stabilizer systems, fruit fillings and, 74

Supplier applications support, supplier evaluation and, 299–301 Supplier control, customer control vs., composite factors in hydrocolloid pricing and, 276 Supplier costs, customer influence on, 286 Supplier evaluation form, 308, 309 Supplier evaluation parameters, 289 applications support, 299–301 caring/responsiveness/respect, 303–304 certifications, 293–294 clarity of communications, 294–296 ease of communication, 296 ethics of supplier, 301–302 future adaptability, 304–305 industry knowledge, 306–307 innovativeness, 305–306 likeability, 307 logistical facility, 297 orientation of supplier, 302–303 product categories and types, 290–292 product quality, 292–293 sales representative, 307–308 technical support, 297–299 Supplier gimmicks, high prices/profits and, 280–281 Suppliers avoiding price increases from/gaining price decreases from, 287–288 high profit mentality of, 275–276 screening, 289–290 Supply and demand fluctuations, true market price for hydrocolloids and, 278 Surimi, 46

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Index Suspending ability, hydrocolloids and, 9 Suspension of particulates/droplets, hydrocolloid dressing stabilizers and, 24 Sweet acidophilus milk, 154 Swiss-style yogurt, 143 Sworn, G., 100 Synergism, defined, 44 Synergistic blend hydrocolloid category, 263t, 267–268, 269–270 Synergy, multiple gums in formulation and, 10 SySNF. See Soy solids not fat percent Takigami, S., 96 Tapioca components and properties of, 219t in meat products, 38 Tapioca starch, in yogurt, 144 Tara gum in cream cheese, 159 in frozen dairy desserts, 111 preventing cracking in bakery fillings with, 102 processing conditions for bakery fillings and, 84 synergy between xanthan gum and, 97 Technical service commitments, suppliers failing to keep, 295 Technical service (or technical support), supplier evaluation and, 297–299 Techwizard, 126 Temperature dissolving hydrocolloids and influence of, 2 gelling hydrocolloids and influence of, 3–4

341

homogenization, for frozen dessert mixes, 138 Tetrasodium pyrophosphate (Tetron), 3, 178, 178t in internal set beef formulation, 200t in neutral pH systems, 183 in restructured burger-type products, 199 Texture in cheese products, 141–142 grades, hydrocolloid functionality and, 256 hydrocolloid functionality and, 5–6 Thermal process flavors, 215 Thermometers, dissolving hydrocolloids and accuracy of, 2 Thixotropic behavior, of microcrystalline cellulose, 95 “Tiger striping,” in turkey breast, 45 Time of suppliers, valuing, 286 Tinctures, 215 Toaster pastry fillings, 80–81 formulation for, 81 procedure for, 81 solids content in, 80 Total solids percent, for ice cream and frozen desserts, 116 Total soy solids percent, for ice cream and frozen desserts, 119 Transparency, of gums, 7 Tri-Blender, frozen dairy desserts and dispersion of stabilizer, 132–133 Tricalcium phosphates, 3, 5 Triggers, in internal setting process for restructured foods, 182 Triglycerides, flavor protection and, 216

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Trisodium citrate, 178t, 179, 183 Troubleshooting, hydrocolloids use and, 16–17 True market price, for hydrocolloids, 277–279 TSPP. See Tetrasodium pyrophosphate (Tetron) TSyS. See Total soy solids percent Turkey, pale, soft, and exudative (PSE) raw material in, 41 Turkey breast carrageenan and, 44–45 typical formulation for, 45t Twin screw cooker extruder, 239 Tzatziki sauce, from yogurt, 149 UHT pasteurization, for frozen dessert mixes, 137 Unfrozen water, limiting amount of, in frozen dairy desserts, 110 United States cheese standards in, 162–163 cheese varieties in, 161 cream cheese regulations in, 158 reduced fat sour creams in, 155 salad dressings marketed in, 19 sour cream regulations in, 154 U.S. Department of Agriculture (USDA), 41 Vat pasteurization, for yogurt, 143 Vat set yogurts, 143 Vegetables internal set–acid pH, system for, 205 internal set–neutral pH, system for, 197 restructured neutral pH, 196–197 Vegetarian diets, gelatin concerns and, 146 Vinegar, in salad dressings, 20, 21 Viscosity

alginate solution, degree of polymerization and its effect on, 173t of canned fruit filling, 70 defined, 258 at different concentrations in water viscosity, 260t facts related to, 259 grade differentiation and, 258–259 gum arabic vs. OSAn starch, 220 hydrocolloid dressing stabilizers and, 23–24 for typical alginates, 173, 174 typical ranges of hydrocolloids, 260t verification of, 292 Water in bakery fillings, 83–84 bakery filling stabilization and, 81–82 carrageenan fully hydrated in, 41 in salad dressings, 20 Water gels, meat products and synergism in, 40 Water purification system, hydrocolloids use and, 17 Water source, checking, hydrocolloids use and, 17 Waxes, flavor protection and, 216 Waxy corn, components and properties of, 219t Waxy corn starch micrographs of, showing maximum and lower viscosity, 147 in sour cream, 155 in yogurt, 144 Waxy maize, in yogurt, 143 Waxy potato, components and properties of, 219t

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Index Waxy rice, components and properties of, 219t Welinga, W. C., 87 Wheat components and properties of, 219t in meat products, 38 Whey, flavor protection and, 216 Whey solids percent, for ice cream and frozen desserts, 116 Whipped yogurts, 148 Written language skills, clarity of communications, supplier evaluation and, 295 Xanthan gum, 2, 32, 53 in application blends, 269 in bakery fillings, 96–98 benefits/liabilities with, in salad dressings, 25 boilout in bakery fillings and, 103 in bread, 53 in cake, 55 in cheeses, 162t competitive era of hydrocolloid history and, 251 in cottage cheese, 157, 158t in cream cheese, 159 in cream fillings, 79 in custard filling, 77 in egg pasta, 59 in fried cornbread muffins, 63 in frozen dairy desserts, 111 hydrocolloid dressing stabilizers and, 23 locust bean synergy with, 87 in nonbaked fried cornbread, 65 in pancakes, 60, 61 in pizza dough, 66 pumpkin pie and stabilizing with, 76

343

in reduced oil flour tortillas, 58 in Ricotta cheese, 159 solubility of, in cold water, 97 special stabilities, grade differentiation and, 262 superior freeze-thaw ability with, 97 synergistic hydrocolloid blends and, 267, 268 synergy between tara gum and, 97 transparent versions of, 7 viscosity and, 258 range for, 260t wide use of, 52 Xanthomonas campestris, 96 XG. See Xanthan gum Yamada, T., 226 Yogurt alternative stabilizers in, 143–144 for children and toddlers, 148 consumption of, 142 cup set, 143 digestive benefits with, 147–148 dips, 148 drinkable, 149–151 low-fat, formulation and processing parameters for, 152t equipment for mixing and packaging, 142–143 freeze-stability for, 145 Greek-style, 149 increasing sales of, 149 inulin in, 148 new products, 148 pasteurization for, 143 pectin in, 150, 151 protein aggregate size and, 150–151 spoonable, 143 gelatin in, 146–147

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344 Yogurt (Cont.) low fat, formulation and processing parameters for, 152t stirred, 143 Stoke’s law, protein stabilization and, 150 strawberries in, 142

Index textual defects in, 148 vat set, 143 viscosity and cross-linking and processing, 145 effects of shear and starch cross-linking level on, 146