Risky Food, Safer Choices: Avoiding Food Poisoning

R I S K Y F O O D S, S A F E R C H O I C E S

About the authors PETER CEREXHE is an award-winning journalist who has also worked as a lawyer and editor. He spent eight years as a journalist for Choice magazine (the journal of the Australian Consumers’ Association). He is the author of the highly successful book Before and After Retirement (Choice Books, 1998) and has contributed chapters to several other titles. DR JOHN ASHTON is a conjoint Senior Lecturer in Food Technology at the University of Newcastle and also directs a leading Australian food testing laboratory. He is the author of several highly successful books on health and the environment, his most recent title being The Perils of Progress (UNSW Press, 1998). Dr Ashton is an elected Fellow of the Royal Australian Chemical Institute and a professional member of the Australian Institute of Food Science and Technology.

PETER CEREXHE

+ JOHN ASHTON

R I S K Y F O O D S, SAFER CHOICES AV O I DI N G FO O D P O I SO N I N G

E . co l i

salmonella

listeria

c ry p t o s p o r i d i u m

g i a rd i a

UNSW PRESS

AC K N OW L E D G E M E N T S A book like this one crosses many areas of individual expertise and relies on the contributions of experts and on a vast range of published research and opinion from all corners of the world, whether in academic or popular journals, websites, books or newspaper reports. The most helpful of these references are listed under Further Reading, for those who wish to pursue matters in greater depth than is possible here. We recommend these references to you. The authors would like to take this opportunity to acknowledge the specific assistance and support of those who aided this project. In particular we would like to thank the following people, gratefully acknowledging their contribution: Dr Michelle Adams and Dr Bob Hosken at the Centre for Food Industry Research and Development at the University of Newcastle; Dr Sid Cole, Fellow of the Australian Institute of Food Science and Technology; and Matt O’Neill and staff at the Australian Consumers’ Association. Rosemary Stanton kindly read the manuscript and made many useful suggestions.

CONTENTS 4

INTRODUCTION • Why get so worked up about it all?

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PART I UNDERSTANDING FOOD POISONING, AND YOUR PROTECTION

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CHAPTER 1 • WE’RE ALL IN THIS TOGETHER • What is food poisoning? • What are the symptoms? • How big is the problem? • The food they call back • Can you tell if food is ‘off ’? • How do you protect yourself?

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CHAPTER 2 • KNOW YOUR ENEMY! • Bacteria • Viruses • Yeasts and moulds • Parasites • Accidental extras

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CHAPTER 3 • WHO IS MOST VULNERABLE? • Children • Those with reduced immunity • Why are older people at greater risk? • Pregnant women •

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CHAPTER 4 • HOW DO I PROTECT MYSELF, MY FAMILY AND FRIENDS? • How your body protects itself • Food storage, preparation and preservation • Recognising food additives •

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PART II A WALK THROUGH THE SHOPPING CENTRE

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CHAPTER 5 • THE DELICATESSEN • Smallgoods • Rules for smallgoods • Herbs and spices • Dairy foods • Jams and preserves • Pate

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CHAPTER 6 • THE GREENGROCER’S SHOP • Potatoes • Mushrooms and fungi • Alfalfa sprouts • Packaged raw salads

A UNSW Press book Published by University of New South Wales Press Ltd University of New South Wales Sydney 2052 Australia www.unswpress.com.au © P. Cerexhe and John Ashton 2000 First published 2000 This book is copyright. Apart from any fair dealing for the purpose of private study, research, criticism or eview, as permitted under the Copyright Act, no part may be reproduced by any process without written permission. Inquiries should be addressed to the publisher. National Library of Australia Cataloguing-in-Publication entry: Cerexhe, Peter. Risky foods, safer choices: avoiding food poisoning. Bibliography. Includes index. ISBN 0 86840 522 1. 1. Food poisoning. 2. Food contamination. 3. Food. 4. Food service. 5. Food handling. 6. Food industry and trade. 7. Cookery. I. Ashton, John. II. Title. 363.192 Printer Griffin Press, Adelaide Designer Di Quick

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CHAPTER 7 • THE BUTCHER’S SHOP • Spoiled meat Minced meats and sausages • Whole poultry • Marinated meats • Protection strategies

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CHAPTER 8 • THE FISH SHOP • Fishy risks • A tale of toxins • Molluscs • Processed fish

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CHAPTER 9 • A SWEET TOOTH • Cakes • Icecream and other frozen treats • Chocolate

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CHAPTER 10 • THE SUPERMARKET • Canned foods • Frozen foods • The good egg • Vegetarian meat substitutes • ‘Use-by’dates • Is that mould? CHAPTER 11 • DRINKS • The town water supply • Is bottled water the answer? • Fruit juices • Milk drinks • Dirty ice CHAPTER 12 • TAKEAWAY FOOD SHOPS • Hamburgers • Salad bars • Doner kebabs • Rice • Pizza • Chicken • Sandwiches: the safe alternative? • When safer choices are important to you • Food workers sick at work • Picnic tips

105 PART III TRAVEL, PARTIES AND WHO LOOKS AFTER US 106 CHAPTER 13 • ESCAPING THE TRAVEL BUGS • Which countries pose the greatest risk? • Cruise blues • Choosing a restaurant • Safe water • Bottled water: is it safe? • Probiotic aid • Salads: a difficult choice

117 CHAPTER 15 • SCHOOL LUNCHES • Canteen or home-packed lunches? • Tips for packaged lunches • Children and gastroenteritis

120 CHAPTER 16 • FOOD ALLERGIES • What are the main food allergens? • How can I find out if I have a food allergy?

124 CHAPTER 17 • STORING FOOD • The freezer: what can it do for me? • The refrigerator • Fridge and freezer tips • How long will food last? • In the pantry

134 CHAPTER 18 • YOU AND YOUR KITCHEN • How should I clean my kitchen benches? • Cutting boards: wood or plastic? • Personal hygiene

139 CHAPTER 19 • THE BUSINESS OF FOOD • Quality control • Detecting the foreign legion • Testing and complaints • New technologies to the rescue • New hopes, new problems

148 CHAPTER 20 • FUTURE UNCERTAIN • Are the risks increasing or decreasing? • Getting around and becoming known • Are we overly dependent on antibiotics? • Changing our preferences The gene armoury • A role for government

157 CHAPTER 21 • ONE FOR THE ROAD

158 GLOSSARY 159 FURTHER READING

114 CHAPTER 14 • IT’S MY PARTY … • 160 INDEX Cooking in advance • Dealing with leftovers

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INTRODUCTION: WHY GET SO WORKED UP ABOUT IT ALL? Food poisoning happens; we all know that. But it usually passes quickly and we get well again. It was just bad luck — or is there more to it? The world we live in is very different from the world of 30 years ago. Not only are there more people, more travel and terrible flu, and other viruses moving around the world with astonishing speed, but also new food-poisoning bacteria such as the ingloriously named E. coli O157: H7, first reported back in 1982. This bacterium, which is now carried in the intestines and faeces of up to 40 per cent of cattle in some countries, can cause not only vomiting and diarrhoea but can leave an affected child permanently with diabetes. It has also been known to produce brain damage. Fortunately not all food-poisoning bacteria produce such serious and permanent symptoms. And, in a country like Australia, we are mercifully free from much serious foodborne illness. Yet the human race is inadvertently playing a role in its own food hazard development. Technology has produced the conveniences of mobile phones, microwave ovens, cheap travel, mega farms and fast foods, but somehow in the equation we have also created an environment conducive to the emergence and spread of food-poisoning micro-organisms with the potential to affect us all. This will change the way we live. Many of the food-poisoning bacteria which now concern authorities, such as Campylobacter jejuni, have only emerged in the past 25 years. Yet more than 11,000 cases of Campylobacter jejuni food poisoning were reported in a small country like Australia in 1998, with an untold number of cases going unreported. This changing food environment has necessitated the writing of this book. It contains the information you need to help you to choose,

store and prepare food in ways which will reduce the risk of contracting a foodborne illness. We discuss things like meal planning, cooking temperatures, safe food storage and many other factors which, we believe, now require more diligence than we perhaps have given them in the past. There are real incentives for developing good habits: ¥ Your food will taste better and be better for you. The same good practices which keep food safe also present you with meals that are fresh and with their full complement of nutrients. Bad practices degrade your food as the bacteria multiply. Good practices deliver food with the right aromas, textures and tastes. ¥ You’ll save money. Doctors ’b i l l s, medicines and time off work (or a soured holiday) are the expensive consequences of a bout of food illness. ¥ Your friends will continue to come over to your house. If guests feel they got food poisoning at your place, or if they saw the way the food was presented and were not impressed, you might be left wondering why they no longer accept your dinner invitations. ¥ You learn how to look after vulnerable people, helping them to good health. Many of the foodborne pathogens are of particular concern to those who are most vulnerable in our society — the frail elderly, babies and very young children, those undergoing cancer treatment or otherwise with lowered immunity. Good food practices help support the health of your family and friends.

To help you with this task, we have provided a great deal of information: about microorganisms which can make us sick, how they get to us, how they work within us, our defences, how the food industry works, and what the future holds. Along the way we have simplified the complexities of much of this information so that you might more readily

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grasp principles and rules which you can then apply in your daily life, whether shopping, attending functions or simply eating at home. This book is divided into three parts. Part I highlights the prevalence, dangers and impact of food poisoning, lists the most common food-poisoning agents and how they affect you, and lays down some general rules to protect yourself and your family. Part II takes you on a walk through the shopping centre, with chapters dealing with separate shops such as the delicatessen or fish shop, and points out which foods are riskier, and which are safer choices. Part III looks at food poisoning risks from travel destinations, parties and packed lunches, what you can do to store and prepare food more safely, what the food industry does, and other risks to do with food such as allergies and genetically engineered products. Many of the lists, tables and tips in this book are based on the assumption that certain foods have been treated and handled equally. By returning to basic principles of food science it is possible to suggest that one food is riskier than another. The point might be controversial and could be argued about by experts forever. This book, however, is written for consumers who want some help and guidance in dealing with difficult, sometimes obscure problems. In providing this guidance the writers are, in some instances, stating a personal opinion. We have included many case studies from the United States and Britain, as well as from Australia. In some cases the bacteria or viruses which feature in those overseas stories are more of a problem there than in Australia. Yet they remain relevant to all who travel widely. For example, if you’re one of the thousands of Australians who have embarked on a United States family holiday, it is worth knowing that you should check your hamburger mince has been cooked thoroughly — hamburgers have been an ongoing source of foodborne illness in the United States. Similarly the United States has suffered some major outbreaks of illness traced to local water supplies. Again it is a problem that

Australians are not necessarily prepared for. When we began our research, we considered whether the concern in the United States over safe drinking water and fruit juices was relevant to Australians. By the time we completed this book, Australians had witnessed the frenzy arising from the Sydney water scare and the recall of Nippy’s Aussie Gold and Orange Grove fresh chilled fruit juices for Salmonella contamination. A health concern may arise on one side of the world, but it should no longer come as a surprise to see it pop up in our own backyard. Are you prepared to take a risk of food poisoning? Sometimes the answer will be ‘Yes’, at other times ‘No’. Your own state of health will have a great bearing on how you answer this question. We have found that many people who work in the food industry have safety tips which they apply in their own lives. Some will not eat custard tarts, for example, simply preferring to remove a whole category of food from their ordinary diet rather than take what at most times would be a very small risk. In this book we’ll show you many of these tips. It is important from the outset you understand that such tips are a simplification of very complex issues and processes. A socalled ‘risky’ food, provided it is prepared and handled properly, might be quite safe to eat. At the same time, a ‘safer’ food might strike you down with illness because it was handled by a chef who failed to wash his hands. There are plenty of corporations and advertisers who want to scare us all about the safety of our food supply and the way we run our home kitchens. We reject the fear campaign, and their notion that commercial antibacterial disinfectants are necessary in the home: good food practices and soap and water are completely adequate, and have been for centuries. Without building up the risks or, on the other side, playing them down, we believe that consumers armed with good information will get the best out of their meals — greater enjoyment, greater safety and better health. We hope this book will help you develop a positive attitude to food and meal preparation.

PA RT I

UNDERSTANDING FOOD POISONING & YOUR PROTECTION

E. co l i

salmonella

listeria

c ry p t o s p o r i d i u m

g i a rd i a

CHAPTER

1

WE’RE ALL IN THIS TOGETHER

H AVE YOU EVER SUFFERED FROM FOOD POISONING? Maybe you’ve woken up around three o’clock in the morning, clutching your stomach in pain, and cursing the restaurant where you had dinner. Sometimes you develop a bad feeling about a particular food almost as soon as you’ve put it in your mouth. Minutes, hours, days … food poisoning can be fast or slow. Sometimes you anticipate it (‘I don’t feel good about those oysters!’) and it never shows up. For this reason it can be difficult to know where to lay the blame. Was it last night’s restaurant or yesterday’s lunch of reheated leftovers? Can you rightly call the restaurant and complain to the manager, or should you be looking instead for a problem within your own kitchen? Food poisoning is an issue of great concern to all of us. Maybe you are a parent, wanting to do what is necessary to protect your children. Perhaps you are a business traveller who cannot afford to come down sick while racing to meet deadlines and endure meetings. For some of us it is a matter of caring for friends or

family who are in poor health and at risk of serious illness from any infection — people with compromised immune systems, the elderly, pregnant women and babies. The more you know about food poisoning, the better your chances of enjoying your travels and keeping your family in daily good health.

WHAT IS FOOD POISONING? The World Health Organisation defines ‘food poisoning’ as any illness caused by or thought to be related to the consumption of food or water. It is a very broad concept. In this book we will use the term ‘foodborne illness’. Experts sometimes divide foodborne illness into different categories which assist in their analysis of what is going on. For example, some micro-organisms multiply in food and produce a toxin which poisons us when we eat it; other micro-organisms multiply inside our bodies, having gained access when food or drink are consumed (or fingers licked).

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Not everyone who eats or takes in a harmful micro-organism or toxin will fall sick. Sometimes this is because the ‘dose’ — the number of organisms or quantity and strength of the toxin — is insufficient to cause illness; sometimes the person has a degree of immunity due to prior exposure to the micro-organisms or because they enjoy better health generally. A person who carries the harmful organism, yet shows no symptoms, might still be able pass it on to someone else, who does become ill. We can be symptom-less (‘asymptomatic’) carriers of foodborne pathogens.

¥

What is it that makes us sick ?

Food poisoning is usually the fault of bacteria and other ‘bad’micro-organisms. We get sick because we have consumed them — by eating or drinking, or by putting objects in our mouths that are contaminated with them. The four most common situations that can result in an episode of foodborne illness are: ¥ poor storage of the food ¥ inadequate cooking or reheating ¥ cross contamination: from one person

or utensil/surface to another ¥ infected food handlers.

bacteria are only one type of culprit. There are good bacteria and bad bacteria; there are good chemicals and bad chemicals. Almost everything you can eat is a poison if you swallow too much of it — even vitamins and other healthy things in our food and drink. It is useful to know the different sources of problems so you can then understand which way to treat them, and how to protect yourself.

¥

Who are the bad guys?

As you might expect, there are many things — bacteria and viruses, moulds, yeasts, parasites and chemicals — which can lead to the symptoms we call food poisoning. You have probably heard of Salmonella. There are more than 2300 different kinds of Salmonella bacteria, but you don’t need to know about them all, and not all of them will make you sick! In other words, we can make a more manageable list of the problem bacteria, viruses and other micro-organisms. That forms the subject of Chapter 2. Not all toxins that give us food poisoning come from micro-organisms. There are also some other natural poisons to be aware of: ¥ When potatoes turn green in colour it is

a sign that the poison ‘solanin’ has been produced. ¥ Oxalic acid, found in the leaves of

Once inside our bodies they travel through the stomach and into the intestines. Most food-poisoning bacteria target the cells of the small intestine. Some attach to the intestine walls and start to multiply, effectively colonising the area before producing their toxins; others release the toxin without having to create a colony first, sometimes simply from within the food mass itself; others will pass through the intestine walls and head for other parts of the body, for example, the virus which causes hepatitis A goes to the liver. Then we get sick. However, this is only part of the story. There are many things that make us sick, and

spinach and rhubarb can, in theory, lead to kidney damage as a result of the formation of insoluble calcium oxalate crystals. ¥ The sea is home to some very power-

ful, all-natural toxins. The toxin in puffer fish has been known to kill the person who eats it. In Japan this fear is part of what attracts the thrill-seeking diner. But it’s not just a concern for the Japanese. Puffer fish has turned up, accidentally, in a frozen-food product sold in Australia. When the company became aware of the mix-up, the product was recalled. Another seafood poison is ‘ciguatoxin’, which has also led to a food recall in

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Australia. This toxin starts in marine plants which are then eaten by small fish which, in turn are eaten by larger fish. As it moves up the food chain we see the concentration of the poison in large fish caught near coral reefs. The ones to be cautious about are large predators, such as snapper, coral trout, coral cod, Spanish mackerel and red emperor. ¥ Some toadstools and mushrooms can

be very toxic. According to a recent radio report from Russia at least one person in that country dies each day from eating the wrong type of mushroom.

¥

The most common causes of food poisoning

The most common causes of food poisoning in Australia (in descending order) are: Campylobacter; Salmonella; Hepatitis A; Shigella; and Yersina. In the United States the order goes: Campylobacter jejuni; Salmonella; Shigella; Cryptosporidium; followed by E. coli 0157: H7. And in Britain the top five are: Salmonella; small round structured virus; Clostridium perfringens; Bacillus cereus; and fifth, Campylobacter. While all three nations face foodborne illness from all of these, there is a shift in emphasis between those at the top of each list. (Some of the differences depend on the intensity of follow-up of cases by public health authorities, and on the ability of laboratories to detect food illness agents at work.)

WHAT ARE THE SYMPTOMS? Symptoms of food poisoning may include the following: ¥ diarrhoea — watery, maybe even bloody ¥ nausea ¥ vomiting

¥ dehydration (due to fluid loss from diar-

rhoea and vomiting) ¥ fever ¥ pain in the stomach or abdomen ¥ swelling in the abdomen ¥ dizziness.

In extreme cases, severe illness or death can result from certain foodborne pathogens. Don’t be alarmed! Not all food poisoning is fatal. In Australia, recent killers have been: Salmonella; Vibrio parahaemolyticus (cholera); E. coli; Staphylococcus aureus. This represents only six deaths over a 15-year period (1980– 1995). However as this book was going to press, six fatal cases of listeria associated with eating fruit salad were reported. Food poisoning is not a big killer in Australia. If you find yourself in a poor nation, however, the risk becomes more real. In countries like Australia, New Zealand and Britain we grow up with little appreciation of the risk elsewhere on the planet. Having said that, the risk (although small) of a life-threatening attack of food poisoning, remains real — even in a developed nation. At the end of 1998, 12 people died in the United States from what is believed to have been packaged meat tainted with Listeria. It was a single instance of meat contamination. Two years earlier, 20 elderly people died from an E. coli O157: H7 infection in central Scotland. These numbers for developed countries are relatively small when the size of the population is considered. It is a tragedy when it happens, but it is not often, and few die.

¥

Chronic diarrhoea

For some people a bout of diarrhoea can last for weeks. Is food or drink to blame, or does the problem lie elsewhere? Diarrhoea can be caused by food poisoning. At fault may be parasites such as Giardia and Crypto sporidium, viruses like Norwalk or Rotavirus, or bacteria such as Campylobacter, E. coli,

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Listeria, Salmonella or Shigella. But there are many other reasons for chronic diarrhoea which should not be ignored, and for which medical treatment should be sought, including: ¥ the use of antibiotics ¥ cancer, and cancer-treatment drugs ¥ diabetes ¥ colitis ¥ food allergies ¥ some food additives or components

(e.g. fructose, sorbitol and others) ¥ medications for treating high blood

pressure ¥ Crohn’s disease ¥ thyroid and endocrine diseases ¥ previous surgery or radiation of the

abdomen or gastrointestinal tract.

HOW BIG IS THE PROBLEM ? Food poisoning figures are very uncertain. In May 1999, the Australia New Zealand Food Authority (ANZFA) released a report estimating that 11,500 Australians suffered from food poisoning each day, costing the nation more than $2.6 billion a year. According to the research, absenteeism from work due to food poisoning cost Australia more than $370 million in 1996–97 alone. While highlighting just how safe the food supply was, ANZFA said Australians face a 1-in-5000 chance of getting food poisoning from a meal, out of an estimated 20 billion meals eaten in one year. Some authorities believe food poisoning is on the increase. In 1995 the US Department of Agriculture’s Food Safety Branch attempted to estimate losses to the US community from foodborne illness. Including medical costs and lost productivity, it came up with a range of US$5.6-9.4 billion annually. Four years

later, in early 1999, the US Department of Agriculture’s Undersecretary for Food Safety placed the range much higher, at between US$6.6–37 billion annually. The US Centers for Disease Control and Prevention (CDC) reported the findings of the FoodNet surveillance project in April 1998: ‘The overall burden of diarrheal disease is great. FoodNet estimates that 360 million cases of diarrheal illness occur per year, resulting in approximately 28 million medical consultations.’ The CDC estimated, from its research, that approximately 8 million cases of foodborne bacterial infections occurred in 1997 in the United States. A study of reported cases of food-related illness in England and Wales from 1992 to 1994 identified 1594 distinct outbreaks, affecting at least the 34,158 people who reported to a doctor or hospital. Of these, 2 per cent were admitted to hospital, and 55 people died. Over the three years of the period under review, half the cases were foodborne, and a further 40 per cent were passed by person-to-person contact. The reported causes also vary. According to the United States’ CDC, there are more than 250 different diseases which can be caused by contaminated food or drink. Some are no longer the big problems they once were (such as botulism) while notified cases of certain others may be on the increase over the last decade or so (for example, reported infections due to Listeria). It is not a static picture but a moveable feast of sorts: sometimes the figures go up, sometimes down. More than 39,000 cases of salmonellosis (illness due to Salmonella) were documented by the CDC in 1996 alone. However, this is just the tip of the iceberg. Experts estimate that, in the United States, the true number of cases falls in the range 696,000 to 3.8 million each year. This, of course, is a vast range of possible cases, serving to indicate just how inexact is our knowledge of the full impact of food poisoning and food intoxication in our communities. Even allowing for those statistical

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short-comings, the numbers are huge. In practice few people who come down with foodborne illness seek medical attention or otherwise are recorded as an official statistic. That is why the health authorities talk about wide estimates rather than hard numbers. People suffer at home, missing the odd day of school or work, perhaps blaming the flu (many of the symptoms are similar) or shrugging their shoulders and getting on with life. Food poisoning is rarely fatal in Australia. In a substantial review of the situation in Australia for the years 1980 to 1995, performed by Scott Crerar and others and published in the Medical Journal of Australia, 128 outbreaks of foodborne disease were identified. Almost 6000 people were affected by these outbreaks, but only 185 were hospitalised, and only six people died. It is one thing to know that not many Australians die or end up in hospital thanks to foodborne illnesses. The dramatic cases are comparatively few, given the size of the population and the number of meals, foods and beverages we consume. But what about the less dramatic instances? How often does one of your family members come down with the symptoms of food poisoning or some foodrelated illness such as mild diarrhoea, nausea or pain in the belly? If we knew the answer to this question we would have a much better understanding about the real impact and cost to the community of foodborne illness. Research is currently underway in both the United States and Britain to find the true incidence of foodborne illness for their populations. In fact Australian scientists helped design the surveys currently being used in the US research. Initially it seemed that Australia would not be carrying out its own research. However, late in 1998 the first Sentinel Surveillance Project got underway in Australia to find out how many of us suffer from food poisoning and other foodborne illness, and how often it strikes. Taking place in the Hunter region of New South Wales, the project by the Hunter Public Health Unit of the New South Wales Government, involves surveying an area with a population of

500,000 people. In particular the researchers will be looking for evidence of action of two of the most common harmful food bacteria: Salmonella and Campylobacter. The first results are expected by the end of 1999. An earlier pilot study took place in Canberra. For that study, telephone surveys were undertaken in households throughout the city, questioning the person who was the food handler at their home. Results indicated that up to 60 per cent of diarrhoeal illness could be the result of poor food-handling practices at home. Research from the United States confirms one important finding of this Canberra study: ordinary householders don’t appear to blame their own food-handling practices, or recognise the hazard they truly can be. Foodborne illness also appears to be on the increase in the United States where there are around 400 to 500 outbreaks reported annually. In part this is possibly due to better recording and more thorough research, but we can’t discount the possibility that more people are simply getting sicker more often. Important contributing factors may be the ways we run our kitchens, changes in the foods we eat, and trends in how and where we eat our meals. We will consider these factors later.

¥

Where does illness strike most ?

It is common for the food industry to lay the blame for food poisoning on poor hygiene practices in the home.Yet in Australia, ANZFA considers that 80 per cent of foodborne illness occurs outside the home. Still much food-related illness is preventable. The British researchers noted: Most of the outbreaks reported and the associated morbidity and mortality could have been prevented by following standard food hygiene practices, implementing infection control policies, and ensuring that food entering kitchens was of the highest microbiological quality possible.

A review of instances of food-related illness in England and Wales from 1992 to 1994 investigated 1594 general outbreaks. The table

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NUMBER OF OUTBREAKS OF FOOD BORNE ILLNESS FROM VARIOUS LOCAT I O N S Place

Mainly Mainly person f o o d b o rn e to-person

Nursing homes and similar institutions

59

199

Hospital

19

156

Restaurant

170

2

Hotel

75

25

Home

101

6

Schools/colleges

30

64

Source Survey of England and Wales, 1992–94, US Centers for Disease Control and Prevention, CDR Review, 29 March 1996.

above shows the most common ‘settings’ or places where the illness was picked up. P R Are homes safer than eating out? There’s a lot of difference. Taken as a whole, eating out at restaurants, cafes, canteens, pubs and hotels accounted for 27 per cent of outbreaks; nursing homes and the like added 22 per cent; and hospitals 15 per cent. The private home only accounted for 9 per cent of outbreaks. Also interesting is just how often a function or party was the occasion when the bad deed took place. The vast majority (88 per cent) of outbreaks connected with private homes occurred at wedding receptions, dinner parties, engagement and birthday parties, barbecues and other group meals. Just over half the outbreaks tracked down to commercial premises (such as restaurants) were also functions, not normal public trading. Clearly the function, whether at a person’s home or in a commercial setting, is an occasion calling for greater care by caterers and consumers alike. Experts have said that the practices and facilities found in the home are not appropriate for catering for large numbers of people. In many outbreaks the food was prepared at someone’s home and

then transported to the place of the party (a community hall, for instance). As you read through this book (particularly Chapter 19) you will see the lengths to which commercial premises must go in order to provide an acceptable level of food safety. It is beyond what most of us would be prepared to do in our own homes.

THE FOOD THEY CALL BACK Have you ever bought a food product which was later the subject of a food recall campaign? Usually the recall is brought to the attention of the public by a special notice in the newspaper, or a sign might be displayed at the entrance to the supermarket. In the worst cases, where numbers of people have become sick after eating or drinking the product, you’ll hear about the problem on the radio or television. Food recalls only deal with a small number of the foods and occasions where consumer health is placed in peril. Nevertheless, they are well documented, and that helps us learn useful information about where and how foodborne dangers arise. For a start, food recalls are not to be dismissed as something that only happens to ‘bad’ food manufacturers. Some of the foods which have been subject to a product recall campaign since the mid-1990s include well known brand names. The list and quotes on the next page are from the list of public recall notifications compiled by the Commonwealth Department of Industry Science and Tourism (Consumer Affairs Division). As far as we are aware, all those recalls listed above were instances of the manufacturer or distributor taking preventive action to look after their customers where contamination or a foreign object was introduced (or was suspected of being introduced) to the food accidentally. The second point to note is that no food group or packaging style seems immune: from dairy to meat and fish; vegetables to snack foods; cans, glass jars and packet foods. These days it seems there are a lot of food

F OOD RECALLS IN AU S T RAL I A Attiki fetta cheese BiLo choc-coated icecreams

‘Listeria monocytogenes c o n t a m i n a t i o n ’ ‘May be contaminated with Listeria’

Cadbury-Schweppes black forest fruit-and-nut chocolate blocks

‘Consumers with an allergy to nuts may have an allergic reaction’

Classic and Josephine LA Gourmet various dips

‘May be contaminated with Listeria monocytogenes’

Farmland (Coles), BiLo and Alpine mud cakes

‘There may be an omission of eggs being listed on ingredient labelling’

Don Latvian liver spread and deli supreme kabana

‘Contaminated with Salmonella bacteria’

Golden Circle canned peas

‘Does not contain packing liquid (syrup) therefore cans have not received the scheduled thermal process’

Heinz apple yoghurt desser t baby food

‘May contain glass fragments in the jars’

Bird (Pontiac Trading Company) peanut snack

‘High level of fungal contamination’

Salmon King smoked salmon

‘May be contaminated with Listeria’

Santos crushed nuts and crushed mixed nuts

‘Possible Salmonella contamination’

Plumrose (Simplot) canned chicken, ‘Damage to cans may allow air penetration resulting in turkey, deli ham and leg ham product deterioration and potential health risk’ Smith’s ‘Twisties’ (cheese and chicken)

‘May contain fragments of fine wire’

Streets ‘Grave Robber’ icecream

‘Confectionary pieces contained in the icecream are high in lead and cadmium’

Giardiniera (Triou) pickled vegetables

‘Possible chemical contamination during manufacture (formaldehyde)’

recall campaigns. Are there more than ever, or are we just more aware of them? The numbers of recalls in Australia for food and beverages for the years 1986–97 are shown on page 15. In the late 1980s the numbers hovered around five to seven each year. This represented roughly 2 or 3 per cent of all product recalls — including cars and other household products — for the year. In the early 1990s the numbers and proportions jumped to a new level. Proportionally, food recalls were increasing as part of the total mix of consumer product recalls.

Another leap, in the mid-1990s, saw food/ beverage recalls hit new heights: 52 recalls in the one year, representing 15 per cent of all consumer product recall campaigns. Therefore we can say: yes, the numbers of food and beverage recalls have been increasing; and yes, food and beverage recalls represent an increasing proportion of all consumer product recalls. This doesn’t necessarily mean that there are more problems than ever with the safety of our food supply. It might simply be a case that more companies are coming forward, or

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being caught, when they have a problem with their food and beverage products. Or it might be a case where a bit of both is going on. In the United States in 1998, by comparison, there were 39 food-related product recalls. Surprisingly almost all concerned meat. Of these, the largest single problem product was minced meat (for hamburger patties and otherwise), with 13 occasions. Ham and sausages faced four recalls each; chicken products six (three of which were due to metal objects turning up in the food); and Frankfurts three. Around half of all recalls were for bacterial contamination, while another seven involved bits of metal. In Australia, too, a surprising number of recalls are to do with foreign objects appearing in the foods or drinks. In July 1995, food recall campaigns were launched over metal shavings (some packs of Kellogg’s ‘Rice Bubbles’ and ‘Coco Pops’), glass fragments (glass jars of Ayam seafood and chicken curry paste), and stainless-steel wire from a manufacturing sieve in cans of infant formula (‘Infasoy’). Many ‘foreign object’ recalls are due to food contamination by broken parts of the manufacturing assembly line: a nut falls off a bolt in the machine, a wire sieve wears out and fragments, a piece of electrical wire falls out. Others are more unusual: a capsule of antibiotic Ampicillin Trihydrate found its way into some seedless dates; wire bristles from a brush ended up in some wholemeal fruit bars; and caustic cleaning solution contaminated milk. Another type of foreign object contamination which also might lead to a recall campaign is where the wrong food gets into the p a c k ag e. While there might be nothing wrong or unhealthy about the ‘foreign food’ itself, the labelling of the product is now incorrect and, for some members of the community, there might be a health issue. Allergies are a classic example: peanuts in chocolate bars, hoummos and rice crackers; gluten in a pack of sausages labelled ‘gluten free’. You can understand the potential

health risks these types of mess-ups can bring about. Foreign objects represent a large proportion of all food and beverage recalls: around 45 per cent. However, unlike food recalls due to bacterial contamination, it is generally the case that only a few packs — maybe only one — have been found to be affected. By comparison, micro-organisms represent the largest threat to populations of people.

CAN YOU TELL IF FOOD IS ‘OFF’ ? Food recalls are only the tip of the iceberg. If the food world is full of dangers — the vast majority of which, we hasten to reassure you, will pass you by — it is fair to ask: Can I pick bad food from good food? Can I tell if food is ‘off ’ or ‘spoiled’?

NUMBER OF FOOD RECALLS IN AU S T RAL I A

Source Commonwealth Department of Industry Science and Tourism (Consumer Affairs Division)

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WAITER, THERE’S A TACK IN MY HAMBURGER! In some cases you can certainly rely on your what your senses tell you. There are visual signs that the food has gone, or is going, ‘off ’, spoiled or stale. Have you ever seen: ¥ bread with mould on it ¥ green patches on potatoes ¥ black spots on fruit ¥ fish with dull eyes?

There are also some occasions when you can smell that a food is spoiling. Have you ever smelled:

While eating a hamburger at the beach one day, one of the authors took a bite and was surprised to find a thumb tack sticking into his mouth. How did the tack get there? Maybe the shop used tacks to pin up the meal orders above the food preparation area; perhaps it had begun its voyage in the minced meat from the butcher’s shop. So who should get the blame? There are many opportunities for foreign objects to find their way into food. Sometimes the thing gets there by accident and sometimes it is from deliberate tampering.

¥ a ‘wet dog’ odour from wine ¥ rotten egg gas ¥ sour milk ¥ old meat?

Sometimes it’s your sense of touch which gives the clue. Have you ever felt: ¥ vegetables, such as zucchini, which

have gone soft and squishy ¥ slimy ham?

If you listened to what your mother or grandmother told you, you would know many of the signs that food is either spoiling or, alternatively, is in peak condition. This is important folk knowledge that has helped us survive from one generation to the next. But not all food poisoning is so easily detected. In many cases the true nature of the food or drink can only be known after testing in a laboratory. Food poisoning might not affect the look, smell, feel or even taste of the food or drink. Use your senses, but don’t rely on them in all circumstances. Why not? There is a basic confusion here: the micro-organisms which break food

down and lead to spoiling are not usually the same ones which poison people. (As mentioned earlier, not all micro-organisms are bad for us.) However, the same factors which allow food to harmlessly spoil might also provide an opportunity for pathogens to contaminate the food and multiply. In any event, it is not a good idea to eat food which has spoiled. In many cases there are no obvious signs of bacteria and viruses at work in food and drink, so you cannot always rely on what your senses are telling you. However, in some cases the changes show themselves in one way or another.

¥

Foreign bodies

You should also watch for foreign bodies, such as worms or insects in rice, flour and dried foods. These do not lead to food spoilage in the sense of micro-organism activity, but they can adversely affect the quality and palatability of food. A foreign object can cause a great deal of physical and emotional trauma. A poison, of course, may even be fatal if swallowed. More commonly, however, we hear of fragments of broken glass or wire: a wire sieve may wear

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through and fall apart, a glass jar might shatter under stress. Where do foreign objects come from? There are as many sources as there are objects: ¥ stones, dirt and soil from the fields ¥ timber from pallets and boxes used to

cart the produce ¥ glass and metal from processing

machinery ¥ glass from light bulbs and light fittings ¥ asbestos, fibreglass and other building

materials ¥ bone fragments which have survived

the food processing intact ¥ plastic from packaging ¥ jewellery pins, biros and other personal

effects lost by staff.

HOW DO YOU PROTECT YOURSELF? If we cannot generally pick a potentially harmful food using our senses, how do we protect ourselves? Unfortunately, there can be no 100 per cent guarantees of safety — unless you have a laboratory test all your food before you consume it! Food safety awareness is a mix of: ¥ what causes food poisoning ¥ how we get it ¥ the raw materials in the food ¥ what your senses tell you ¥ where you bought the food ¥ how the shops had stored the food

before you got it ¥ how those who delivered the food to

the shops had handled it For consumers, these things can lead to cuts, choking, broken teeth, infection (resulting from cuts), as well as illness (from dirtborne bacteria).

¥ how you have brought the food home ¥ how you stored the food ¥ how you prepared or cooked the food.

We will discuss these issues in the chapters throughout the rest of this book.

USE YOUR COMMON SENSES Sense Sight (colour change)

Sight (damaged packaging) Smell Touch Taste

Signs Green spores of penicillium on cheese or blue whiskers on bread; white whiskers on zucchini; green patches on potatoes; dark spots on meat; black spots on bananas, apples and tomatoes; silvery colour on meat. Cans which are dented, rusty or have swollen ends; milk and other drink containers which have blown out; open or leaking containers. Foul odours from gas production and bacterial breakdown; soursmelling milk; acrid, ammonia or ‘wet cardboard’ smells. Sticky, viscous, ‘ropy’, slippery, slimy (for example, lettuce, meat, ham), hollow, soft and squishy (vegetables and fruit). Sour, unpleasant, overpowering; not how it usually tastes.

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SUMMARY ¥ Check the newspapers and watch the television news regularly so that you are aware of

any food recalls or other health risks in your community. ¥ Remember that food safety problems don’t just strike small manufacturers; sometimes

the big brands have problems too. ¥ Use your senses and experience to help detect whether food is ‘off ’. However, be

aware that your senses won’t help you detect all harmful changes to food. ¥ Just because a food has gone ‘off ’ or spoiled doesn’t automatically mean if you eat it

you will get sick.

CHAPTER

2

KNOW YOUR ENEMY!

IF WE CANNOT ALWAYS TRUST OUR SENSES AND EXPERIENCE TO WARN US OF FOODS WHICH MAY HARM US, WHAT CAN WE DO TO IMPROVE THE POSITION? The positive message of this book is that you can reduce your risk of food poisoning by knowing a little about the way the pathogens work and the foods they like to contaminate. This chapter introduces the bad guys — the bacteria, viruses, toxins, yeasts, moulds and natural poisons — which give our food supply so much trouble. Along the way you will pick up tips that will help you in daily living and eating.

BACTERIA Bacteria are tiny living things: micro-organisms. They are basic, single-cell creatures, and are so small — around one millionth of a metre in diameter — that you cannot see them with the naked eye. They come in a variety of shapes. The most common of which look a bit like a rod (‘bacillus’), comma

(‘vibrio’), ball (‘coccus’) or spiral (‘spirillum’). Some have many little legs (‘flagella’) which help them move around if they are in a liquid of some kind, but most bacteria can’t move themselves. They get around thanks to the wind or by hitching a ride on people, animals and insects, or in food. As a way of getting to know bacteria better, let’s take a closer look at one of the better known ones: Salmonella. In the United States, Salmonella is one of the most frequently reported cause of foodborne illness. There are many different types of Salmonella, but two (called ‘serotypes’) account for about half of all cases of salmonellosis: Salmonella e n t er itidis and Salmonella typhimurium. Salmonella lives in the intestines of warmblooded animals and insects, and their faeces can also contain Salmonella. Humans can be carriers, sometimes showing no ill effects, but able to pass Salmonella on to others. Animals which harbour Salmonella include chickens and cattle; the pests which invade our kitchens, such as cockroaches, flies, rats and mice; as well as the family dogs and cats.

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Infection with Salmonella can result in long-term illness (such as reactive arthritis) and septicaemia. In some people, particularly the elderly, Salmonella infection can be fatal. A few will develop Reiter’s syndrome. This illness, which has symptoms including eye irritation, joint pain and painful urination, can continue for months, even years, and may lead to terrible arthritis. Foods which have a particular connection with Salmonella include: meat, eggs, icecream, cheese, milk (raw or pasteurised), pate, ham and drinking water. There are three main ways in which Salmonella makes its way into our bodies: ¥ direct contamination from animal faeces ¥ contamination from people who don’t

wash carefully after going to the toilet ¥ cross-contamination from raw foods to

cooked or otherwise clean foods. When animals are slaughtered for food, the Salmonella present in their intestines can, through contact, contaminate other parts of the animal carcase, including the bits people will eat. Animal faeces may cover eggs from chickens, ducks and the like, and micro-organisms in the faeces can be absorbed through the egg shell to contaminate the egg itself. During the milking process a cow’s faeces can come in contact with the milk and contaminate it. In plain language, what we’re talking about here is some sort of pathway between Salmonella in an animal’s intestine and contact with raw foods. The second pathway is similar: it is the problem of traces of human faeces getting onto a person’s hands, usually at the toilet, and handling kitchen utensils or food. The third route for Salmonella to affect food is to pass from a contaminated raw food

— uncooked meat or milk — to otherwise ‘clean’ food, such as salad or vegetables. This typically happens if the cook uses the same chopping board for raw meat and the vegetables, or the same knifes and utensils. This is the reason why it is recommended you keep and use different chopping boards for raw meat, cooked meat, and vegetables and salad. Alternatively (but it is harder work) you can clean and sanitise the board before it is used again.

¥

Reproducing trouble

Bacteria really become a problem when they reproduce, and this can happen very quickly in food. Initially there is a ‘lag’ stage when the bacteria get used to the new food they find themselves in. This process could take two or three days, or as little as a couple of hours. Then, once adapted to the place, and under the right conditions of temperature and location, each cell divides to form two cells every 20 minutes or so. This means that if you start with, say, 10,000 bacteria, it will take less than two hours and 20 minutes (plus the lag period) to reach more than one million bacteria. There are large variations in the number of micro-organisms necessary to cause food poisoning. Research reveals that some micro-organisms can cause harm in very small numbers — Salmonella and Shigella, for example. There are documented outbreaks where tests showed only one Salmonella organism per gram of the affected food. Time is a key issue in protecting yourself from food poisoning. In general it takes between four and six hours for bacteria to reach sufficient numbers to make a person ill. Larger numbers mean there is a greater likelihood that enough will survive to be eaten; it also means the incubation period can be shorter. However, the lag stage could extend

TIP

Keep foods out of the temperature ‘danger zone’ of between 5 and 60°C (40–140°F).

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for many hours or days after the food first becomes infected with the bacteria. It won’t always be a quick process. Secondly, the conditions under which the bacteria find themselves are also vital: they will divide and grow more slowly if the conditions are unfavourable. If you know what makes the conditions favourable you’re on the way to knowing how to make life hard or impossible for many types of food-poisoning micro-organisms. Ideal conditions for bacteria growth are: ¥ a temperature range of 5–60°C

(40–140°F). The pace of bacterial growth really picks up around 30–32°C (86–87°F). ¥ an environment which is mildly acidic

or neutral (measured as a pH of 4.5 to 7). Alkaline or very acidic foods inhibit most bacterial growth. Moulds, however, can be quite happy in very acidic foods like fruit juice.

¥ plenty of nutrients for the bacteria.

Bacteria, as living organisms, need their own food to survive. Clearly then, they can either starve or thrive according to the nutrients available in their location. Bacteria prefer foods containing lots of protein: like meat, dairy products and eggs. Deprive them of protein and they find the going tough. ¥ moist rather than dry conditions.

You don’t usually find large numbers of bacteria growing in household foods like flour or custard powder while sitting in the cupboard. However, once you make up the custard or powdered milk, it provides a wonderful haven for bacteria to grow. Moisture can be found either in the food itself or in the place where the food is located (the kitchen, pantry or car boot). An atmosphere of high humidity promotes bacterial growth; dry conditions slow it down.

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THE ACID T E S T ¥ air, or lack of it. Some bacteria need

oxygen (‘aerobic’ bacteria), others prefer to avoid it (‘anaerobic’ bacteria), while a third type (‘facultative’ bacteria) doesn’t mind whether there’s oxygen or not.

¥

Between hot and cold

One of our best tools for fighting foodborne disease is control over temperature. Micro-organisms shut down when it is too cold and are killed when it gets too hot. While there are some exceptions to this rule, you will greatly improve your safety if you keep your food at safe temperatures. Keep foods out of the temperature ‘danger zone’ between 5–60°C (40–140°F). Bacteria positively thrive at around human body temperature, and on hot summer days.

¥

Bacterial toxins

Not every cause of food poisoning is alive. The great exceptions are various poisons or toxins produced by bacteria. The bacteria themselves might come and go, living, reproducing, dying or freezing into inaction. But the toxins they release pay no heed to the various conditions which might stop a microorganism dead in its tracks. What happens is this: bacteria grow inside a food. At a certain point the bacteria release a toxin. Some bacteria release their toxin into the gut after the food has been eaten, while some do this before. With these bacteria it is the toxin that makes the person sick, not strictly the bacteria. But the bacteria are nevertheless dangerous for having this toxic ability. Some of the bacteria which produce dangerous toxins include Bacillus cereus, Clostri dium perfringens, Escherichia coli (E. coli) and Staphylococcus aureus. Some moulds produce poisons known as ‘mycotoxins’. These can be found in many types of grains and nuts, including peanuts, maize and wheat. Such mycotoxins can cause cancer or other serious illness in humans if contaminated foods are eaten over a period of time.

Micro-organisms also do not like being in food which is either strongly acidic or strongly alkaline. They prefer foods which are mildly acidic or neutral. Acidity is measured by the pH level on a scale from 0 to 14.

pH

14 alkaline 7

neutral encourages growth of micro-organisms (4.5–7)

4.5 acidic 0

If you own and maintain a swimming pool you will be familiar with the need to keep the pH in the right range, where the water is clean. Once the pH moves out of that range it does not take long, during the summer heat, for algae to grow, turning the water green and, eventually, almost black in colour. It is something similar for bacteria. One of the ways we try and control the growth of micro-organisms is by manipulating the acid/alkali characteristics of food. For example, jams and most preserves are acidic.

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A E RO M O N A S S P P. What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

Bacteria which produces toxins once the food has been eaten. Diarrhoea, abdominal pain, dehydration. 6–48 hours. 1–7 days Seafood, shellfish and raw foods of animal origin. Contaminated water, commonly from sinks and drains. Cooking readily kills these bacteria.

B ACILLUS CERE U S What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods:

How did it get there? Protection strategy:

A bacterium which can produce enterotoxins (toxins absorbed in the intestine). Diarrhoea, abdominal pain, nausea, vomiting, sometimes fever. 8–16 hours for the ‘diarrhoeal’ toxin and 1–6 hours for the ‘vomiting’toxin. 12–14 hours (heat-unstable toxin); 6–24 hours (heat-stable toxin). Cereals like corn, previously cooked rice, pasta, potatoes, sauces, puddings, cooked vegetables, vegetable sprouts (for example, mung bean), meat, meatloaf, ice cream, fresh or powdered milk, custard, cold soups, puddings, commercial batter mixes, spices, sauces. Foodborne, soil, air and water. Keep foods out of the temperature danger zone.

C AM P Y LO B ACTER JEJUNI What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

A bacterium which can produce a toxin. Diarrhoea, vomiting, fever, tiredness and abdominal pain. 2–5 days or more. Less than 7 days. Raw and undercooked chicken/poultry and hamburger mince, cake icing, water, processed turkey, raw clams, eggs. Faecal contamination and poor handling; contaminated water. Cooking and processing techniques such as salting, acid and heat.

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C LOSTRIDIUM BOTU L I N U M What is it? Signs and symptoms:

Time to sickness after consuming: Illness lasts: Favourite foods:

How did it get there? Protection strategy:

A bacterium which can produce a toxin. Weakness, dizziness, extreme thirst, double vision, vocal cord paralysis (can’t speak), paralysis of digestive system, heart and lungs, uncontrollable convulsions, tetanus-like symptoms. Can lead to death. 12–36 hours. Several months. Home-bottled vegetables and fruits; low-acid or non-acidic canned foods such as tuna; fermented foods; mushrooms; soup and smallgoods such as canned meat vegetables; fish and salami; salmon eggs; garlic in oil; baked potatoes; vacuum-packed foods like lotus roots; smoked fish. From soil, dust, water and air, intestinal tract. Boiling. Adequate heating of cans and contents (100°C or 212°F for seven hours) fixes most cases, although spores require longer heating. Commercially, acidity is a tool used to control it as the bacteria does not grow where the pH is below 4.6. Commercial canneries also use higher temperatures and shorter times (for example, at 121°C or 250°F for 15 minutes) to ensure that spores are destroyed.

C LOSTRIDIUM PERFRINGENS What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

Bacteria which produce spores which, upon germination, produce a toxin in the intestine. Diarrhoea, stomach cramps, headache; vomiting is rare. 6–24 hours 12–24 hours. Large pieces of meat such as pork and rolled roasts, casseroles and meat gravies. A natural contaminant of meat and found in soil, dust, water and sewage. Cook your food in smaller batches, ensuring the food is heated thoroughly. Rapid cooling: do not leave leftovers to cool slowly. Put leftovers in the fridge or freezer in small serves so they cool more rapidly.

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ESCHERICHIA COLI (E. COLI) What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

Bacteria capable of causing foodborne illness by a range of mechanisms. Diarrhoea (may be watery then bloody), dehydration, headache, abdominal cramps and pain; can lead to death. 3–8 days. Several days to many weeks, depending on complications. Meats (particularly beef but also chicken), dairy foods like milk and soft cheeses (particularly if unpasteurised), minced meat, fermented salamis and sausages. Cross-contamination at the abattoir or at home; not washing hands after going to toilet; handling raw meat and passing the bacteria across to cooked foods. Some types can survive refrigerator and freezer temperatures and some have developed resistance to antibiotics. Cooking, washing hands and avoiding cross-contamination in the kitchen help.

LISTERIA MONOCYTOGENES What is it? Signs and symptoms:

Time to sickness after consuming: Illness lasts: Favourite foods:

How did it get there? Protection strategy:

Bacteria. Headache, fever, nausea. Can lead to meningitis, septicemia and death. It can be especially dangerous to aged people, pregnant women (spontaneous abortion or stillbirth possible), and people with cancer or a compromised immune system (can lead to arthritis, brain damage and various internal inflammations). Approximately 3 weeks. Varies, depending on complications. High-protein moist foods such as chicken and soft cheese, unpasteurised dairy foods, pate, fermented sausage, raw fish, leafy vegetables, salads (for example, coleslaw), smoked mussels. From animals, soil, water, sewage, crops fertilised with sewage. Cooking to 70°C (158°F), ensuring that even the centre of the food reaches this temperature. Can grow at refrigerator temperatures, but is killed by short-wave ultraviolet light.

An outbreak of listeriosis, which occurred in France in 1992, was traced to consumption of jellied pork tongues. There was widespread illness leading to the deaths of 63 people. In a startling reminder of the special risk Listeria monocytogenes poses to pregnant women, this outbreak resulted in 22 miscarriages.

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SALMONELLA What is it? Signs and symptoms:

Time to sickness after consuming: Illness lasts: Favourite foods:

How did it get there? Protection strategy:

Bacteria. Nausea, fever, diarrhoea, stomach cramps and dehydration, sometimes fever and chills. Can lead to meningitis, pneumonia or death in elderly or sick people. 12–24 hours, average 18 hours. 24–48 hours. High-protein foods such as chicken, turkey, shell fish, meat, eggs, raw vegetables, unpasteurised milk, and incompletely reheated large, frozen or refrigerated dishes of high-protein food (e.g. from the microwave oven). Faecal contamination from animals, humans, birds. Poor handling. It can be carried by flies and other insects. Cooking to 70°C (158°F) for 10 minutes.

SHIGELLA What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

Bacteria and its toxin. Diarrhoea (sometimes bloody), vomiting, fever, abdominal pain and a continual feeling of needing to go to the toilet. 1–7 days but generally 1–4 days. 4–7 days. Beans, milk products, raw vegetables, salads (e.g. tuna, potato, prawn/shrimp salads), well water. Spread by person-to-person contact, food and personal hygiene, water, flies; faeces of infected people. Good personal hygiene will reduce risk of infection; wash fruit and vegetables with treated or boiled water; children are a high-risk group.

STAPHYLOCOCCUS AU RE U S (‘GOLDEN STA P H ’ ) What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods:

A bacterium which produces a toxin. Vomiting, diarrhoea, stomach cramps, headaches, chills, fever, weakness. 1–6 hours but generally 2–3 hours. 6–24 hours. Ham and deli meats, custard, cream, cheese, milk, prawns/shrimp, smorgasbords, salty and sugary foods, low-acid canned foods; potato; salads of fish, poultry, ham or potato; extended shelf-life refrigerated foods and modified atmosphere foods.

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How did it get there?

Protection strategy:

Carried in nose and facial hair, on hands and by unhygienic handling. Watch for infections on hands of people handling food, or food-preparers with colds/flu, runny nose, pimples, acne, burns. Heating to 70°C (158°F) for 30 minutes.

VIBRIO CHOLERA E What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods:

How did it get there? Protection strategy:

Bacteria producing a toxin (‘cholera’ is the illness). Diarrhoea (sometimes bloody), vomiting, nausea, severe dehydration; can lead to septicaemia or death. 6 hours to 5 days. Up to several days. Raw seafoods including prawns/shrimp, crab and oys ters; in developing nations: water, ice and foods rinsed in water, such as vegetables and rice, soft drinks. Grains and legumes grown in cholera-endemic areas. Human faeces contaminating food and water. Cooking; keeping sewage away from fresh water.

VIBRIO PARAHEMOLYTICUS, V. VULNIFICUS, V. MIMICUS, V. HOLLISAE & V. FUNISSII What are they? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

Bacteria of several species in the Vibrio (cholera) family. Diarrhoea (can be bloody), abdominal pain, cramps, vomiting, headache, nausea, chills and fever; can lead to death. 4 hours to 5 days, depending on type. 3–6 days. Raw or undercooked seafood, particularly oysters, shellfish, clams. They are naturally occurring in the sea and may be linked to sewage contamination. Cooking and drying; can survive refrigeration and freezing

YERSINA ENT E ROCOLITICA What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods:

How did it get there? Protection strategy:

Bacteria and its toxin. Strong abdominal pain, diarrhoea, can lead to ulceration of the colon, dermatitis, lymph system inflammation, septicaemia and arthritis. 2–5 days. 1–2 days but can last weeks. Dairy products where pasteurisation has been ineffec tive or contamination has occurred after pasteurisation, water, ice cream, powdered milk, chicken, vacuumpacked meat, pig meats, seafood. Contamination by animal faeces after the food processing stage, poor handling of food. Cold is ineffective: it can grow at refrigeration temperatures. Cook foods to 75°C (167°F).

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VIRUSES Apart from being the smallest types of microorganisms — as little as one-hundredth the size of some bacteria — viruses are unlike bacteria and fungi in that they can only reproduce once they have made their way inside living cells. They do not grow and increase their numbers inside food. Food is simply a very neat way for the virus to move from outside to inside a body, where it works its way into the cells and can then reproduce. Once the viral numbers reach a sufficient ‘dose’, the host becomes ill. When a sick person vomits, coughs, sneezes or spits, they spread viral particles by the millions in their saliva, possibly passing them to other nearby people. Viruses can survive on your clothing, get picked up on your hands and pass onto the food you are preparing. Extra care must be taken when caring for young children and invalids, as urine and faeces, it should be noted, can also spread viruses. It is estimated that viruses are the cause of around 10 per cent of foodborne illnesses in Australia. Some evidence from the United States, however, places the figure closer to 35 per cent. Two examples of viral illnesses are gastroenteritis and hepatitis. The main trouble spots with foodborne viruses include molluscs, raw fruit and vegetables, and often handled foods such as salads and desserts. Mollusc shellfish such as oysters, mussels and cockles may be contaminated from sewage in the water in which they grow, often coastal or estuarine waters or rivers into which sewage is dumped. The shellfish act as filters, leading to a concentration of the virus. And, of course, such shellfish are often eaten raw or with minimal cooking. Fruit and vegetables which are served raw can carry viruses picked up from irrigating or fertilising them with sewage or sewage-contaminated water. If they are not then cooked, the virus comes straight from

CHOLERA: THE EPIDEMIC THAT WON’T DIE Epidemics of cholera have swept through Europe, Asia and Africa for hundreds of years, killing millions of people and crippling their societies. And then, quite suddenly in the early 1900s, the illness appeared to die out in developed nations. By this time we knew how to construct better sewers and the importance of maintaining a pure water supply for drinking and cooking. In the poorer nations, however, cholera continued to claim lives throughout the century. But cholera continues to appear even in countries like the United States. In 1973 there was a case of cholera in Texas; five years later 11 people in Louisiana came down with it; and another 12 in 1986; and more in the early 1990s. The risk is small, however, in developed nations. But be extra careful when travelling in Central and South America, Africa, Asia and in any country with poorly performing water or sewage systems.

the paddock to your plate. With fruit and vegetables, unlike shellfish, the virus will be found on the surface of the food where it is highly susceptible to heat treatment (cooking). Salads and desserts, which often require much handling by chefs and kitchen staff to get them into the right shape, may also easily be contaminated. Again, salads and desserts receive little or no cooking after they have been handled, which is a perfect opportunity for a virus to pass with the food.

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Viruses pose a particular problem because:

¥ viruses are tough. They can resist chill-

¥ there is no simple means of detecting

ing, freezing, preservatives and ionising radiation, as well as acidic foods and pickling in vinegar.

their presence in food ¥ unlike most bacterial problems, it does

not take a large number of virus particles to pass illness to a person ¥ a cook or waiter might have been cont-

aminating food for days before showing the first symptoms of illness themselves

Fortunately viruses can be killed quickly by heating food to 85°C (185°F). You should understand that you are taking a bigger viral risk with raw foods, especially shellfish (see Chapter 8).

H E PATITIS A What is it? Signs and symptoms:

Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there?

Protection strategy:

Virus. Fever, vomiting, malaise, loss of appetite, followed by jaundice. Death is rare but may occur, particularly in the elderly. Symptoms develop gradually and are usually more severe in adults than children, 3–6 weeks. Up to several months, depending on complications. Oysters, prawns, molluscs. Person-to-person transmission. It comes from the human intestine, passing by poor food handling or by contact with contaminated water (for example, the sewage-polluted water in which the oysters grew or were held; crop irrigation). Personal hygiene; avoiding high-risk foods.

N O RWA L K What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

Virus. Sudden onset of vomiting (may be projectile), explosive diarrhoea and abdominal pain. 15–72 hours but generally 24–36 hours. About 3 days. Orange juice, water, oysters and salads. Person-to-person transmission, comes from human intestine, poor food handling or by contact with sewage-contaminated water. Use only treated water or boiled water for washing salads, food preparation and drinking; avoid raw seafood.

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YEASTS AND MOULDS Yeasts and moulds are living micro-organisms, like bacteria. Yeasts can make food go ‘off ’, accompanied by bubbling, sometimes slime, and an aroma something like beer or wine. There are useful and ‘good’ yeasts (such as the ones used when bread is made or beer is brewed), as well as bad yeasts to avoid. Yeasts are not usually associated with food poisoning: only food spoilage. Moulds are among the most obvious types of food spoiling. You have probably seen their spidery, blue-green powder on old bread; on the skins of rotting oranges; on the top of jams and preserves; or on the side of a block of cheese. Their smell can be pungent, like a wet dog or a wet cardboard box. In fact on some foods you are more likely to find moulds rather than dangerous bacteria. (Generally, bacteria like a wet food with plenty of moisture to help them move around. One of the ways to control bacterial growth is by drying the product, for example, the curing of ham.) Moulds will happily grow at much lower moisture levels. They turn up

on foods like nuts, grains, peanuts, cereals, bread, cheese and jams. Moulds, like some ferns, spread by forming ‘spores’ which blow away to cover other parts of the host food, eventually growing to maturity and producing fresh spores. The mould we have heard most about in the media is the one associated with peanuts and peanut butter. The mould Aspergillus flavus grows naturally, in the field or even after the crop has been harvested, and can produce ‘aflatoxin’, most commonly in peanut and corn crops. The mould produces the toxin in its highest and most dangerous levels in years of drought or other trauma which has damaged those crops. Food standards place an upper limit on the amount of aflatoxin which is permitted in peanuts (not more than 15 parts per billion in Australia), and most manufacturers have equipment to detect it. However, who is checking the peanuts in small health food shops (where you can grind your own peanut paste) or in local street markets? Another famous toxin produced by a mould is patulin, which turns up in apple

ASPERGILLUS FLAV U S What is it? Signs and symptoms:

Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

Mould that produces aflotoxins. Large exposures can produce abdominal pain, swelling due to fluid retention in body tissues (oedema), liver damage, hepatitis; can lead to liver cancer and impaired immune system. Several days or even years, depending on dose. Can be long-term illness. Peanuts, peanut butter, peanut oil, corn, nuts, figs, cocoa beans. Natural mould on the crop, particularly in drought conditions. Government testing of crops.

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juice, organic cider and fruits such as mouldy apples, apricots, cherries, grapes, peaches, pears and plums. Studies suggest it may be a carcinogen. (However, don’t confuse a mouldy taste or odour with the safe but sour, vinegar-like taste that fruit juices acquire. This sourness, which indicates fermentation is taking place, is not a hazard.) What should you do with mouldy foods? In most cases, throw them away or put them in the compost. (See also Chapter 10.)

PARASITES Bacteria and viruses are arguably what most people think about when they turn their minds to foodborne illness. While these are the most common causes of food poisoning there are other problems which come with food. Tapeworm, roundworm and flukes are types of parasites which live inside cattle, sheep, pigs, fish and the like, and can also be found in vegetables which have been irrigated or fertilised using sewage-contaminated

C RY P T OS P ORIDIUM PA RV U M What is it? Signs and symptoms:

Time to sickness after consuming: Illness lasts: Favourite foods:

How did it get there? Protection strategy:

Protozoan. Profuse, watery diarrhoea, abdominal pain, vomiting, low-grade fever, weight loss, loss of appetite, anorexia. It can lead to death in some people with low immunity. 2–14 days. 2–3 weeks but can last 6 weeks. Water used for drinking, food preparation or for swimming; raw meat (particularly sausages and offal), unpasteurised milk, fruit and vegetables. It can pass from person to person in places like childcare centres. From live and dead animals, person-to-person contact, contaminated raw foods and the water supply (arguably from farm and wild animals). Special filtration of water supply; it resists chlorine treatment. It is inactivated by drying heat, such as cooking or boiling, and by freezing.

GIARDIA LAM B L I A (OR GIARDIA DUODENALIS) What is it? Signs and symptoms: Time to sickness after consuming: Illness lasts: Favourite foods: How did it get there? Protection strategy:

Protozoa. Diarrhoea, weakness, nausea, excessive smelly sulfurous burps, wind. 7–10 days. A few days to a few weeks. Water It is found widely in nature; faecal contamination. Filtration and disinfection of drinking water; use of bottled water; boil water for one minute and allow to cool. Do not wash salads in untreated water.

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water. Often this is more a problem in developing nations. Parasites abound in nature, but often our production practices make the problem worse. In aquaculture (an emerging industry where fish, often for sushi, are raised in tanks) the environment can be controlled. Unfortunately aquaculture, through its creation of a monocultural environment, may actually contribute to the spread of pathogens since many competing organisms have been removed from the food chain. Some aquaculture avoids this by using ocean pens. If food is served raw or undercooked — sushi, sashimi, raw beef slices, salmon and so on — the parasites can survive the kitchen and pass to the diner. Once inside, they head for places like the liver, intestine or lung, where they grow and cause problems like malnutrition, hunger pains, increased appetite, muscle pain, headache, vomiting, respiratory problems and convulsions, depending on the type of parasite and the age of the person. There is a parasite we can acquire from handling raw meat, or from cats. Toxoplasma gondii can be picked up if we handle or come in contact with infected, stale cat faeces (in the garden, for example), giving us symptoms similar to a bout of the flu (called ‘toxoplasmosis’). Generally the symptoms pass quickly. But people with low immunity, or pregnant women, should be more careful and wear gloves when preparing raw meat, gardening or handling kitty litter. Indeed if the mother gets infected the baby might be born with the parasite which might interrupt the normal development of the child at some stage. People with reduced immunity can become blind or, in the worst cases, might die from toxoplasmosis. Cooking kills most of the parasites we come across. Freezing is not always as effective.

ACCIDENTAL EXTRAS You eat a meal, you get sick, you blame the bugs. But you may be wrong. There are all sorts of chemicals which get into the food supply. Some are quite harmless, while others become poisonous if they are there in the right amount or if they got into the food at a sensitive time. For example, farmers use chemical pesticides and herbicides to control weeds, diseases and insect pests which might otherwise devour or ruin their crops of fruit and vegetables. We rely on such chemicals for the wide and cheap availability of these important foods, although the demand is growing for fruit and vegetables that are ‘pesticide free’ and ‘organically grown’. A January 1999 US Department of Agriculture survey of pesticide residues in food found low levels of residues in 57 per cent of fruit and vegetable samples, 87 per cent of soybean, 80 per cent of wheat and 15 per cent of milk samples. The samples came from foods originating in 43 states of the United States and 23 foreign countries, so it was a fairly large pool that was surveyed. Putting this together, the researchers found low-level but widespread pesticide residues in as many as 28 foods eaten by Americans. One-quarter of the pesticide residues found in fruit and vegetables had been added after the food had been harvested (for example, while in storage, to keep pests at bay). It is a huge issue, and one day we may have different ideas about what all these pesticides are doing to us — even at low levels. Scientists and chemical manufacturers know the generally accepted ‘safe’ doses of these chemicals, but there is nothing (other than their high cost) to stop the individual farmer using too much of the poison. Education about agricultural chemicals is essential for farmers, though it is lacking in many parts of the world. A second problem occurs if the chemicals are used at the wrong time. The most obvi-

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ous danger is when a crop finds its way into the shops before the chemicals have had sufficient time to become harmless. Pesticides and agricultural chemicals have what’s known as a ‘withholding period’: a period of a number of days during which the fruit or vegetables must not be eaten as it may be poisonous to humans. Other poisonous chemicals which may get into food include: ¥ lead and mercury — heavy metals and

other pollutants in the sea. ¥ disinfectants and cleaning chemicals,

such as caustic soda, used in the food processing machinery to clean and sterilise the workplace; or their containers (such as glass bottles) later used for food or

drink. Benchtops, pots, pans and knives can be contaminated in the same way. ¥ the container itself, which can introduce

a poison into the food. One example is the tin coating used to prevent corrosion of cans. Acidic foods may dissolve some of the tin. ¥ monosodium glutamate (MSG), used as

a flavour enhancer. It is a staple of the restaurant trade and is well known for giving the diner a terrific thirst after eating a meal high in MSG. There may be other more serious reactions to MSG, such as a type of food allergy reaction, and asthma. However, the research is not conclusive. It also occurs naturally and at high concentrations in the skins of some fruits.

SUMMARY ¥ Foodborne illness may be due to bacteria, a virus, a mould, fungus or a non-living toxin

released by a micro-organism. Sometimes protozoa are at fault. ¥ There is often a relationship between particular foods and particular pathogens. ¥ We rely on different tools and techniques to neutralise or control dangerous micro-

organisms. The techniques are usually simple to implement — even in the home — and highly effective.

CHAPTER

3

WHO IS MOST VULNERABLE?

IN TRACKING DOWN THE CAUSE OF A PARTICULAR BOUT OF FOOD POISONING, IT IS HANDY TO KNOW THAT SOME ILLNESSES HIT CERTAIN AGE GROUPS MORE OFTEN OR WITH GREATER SEVERITY THAN OTHERS. For example: ¥ the elderly and the unborn are at

particular risk from Listeria

¥ for Salmonella it is children aged under

one year ¥ for Campylobacter, it is the one to four

age group ¥ symptoms of Giardia lamblia are more

severe in children than adults ¥ E. coli’s ‘enterohaemorrhagic’ forms

appear to have their most profound effect on young children, particularly around the age of four or five.

CHILDREN Nowhere was the reality of an age link seen more forcibly than in the Garibaldi mettwurst incident (see page 49). Here was a salami that was eaten by adults and children, yet almost all those affected strongly by food poisoning (in this case E. coli) were children aged from four months to 12 years, with most cases in a group around four years of age. We don’t really know a lot about why this happens. The connections have only been picked up by researchers who add up the numbers of reported cases. One theory is that children have areas in their large intestines which bind the bacteria or its toxin, whereas in adults these sites have closed. According to this view, these receptors may open again in old age, helping to explain why the elderly are at heightened risk, once more, from certain bacteria. ‘It is a complex situation, largely uninvestigated,’ says Associate Professor Scott Cameron, Clinical Associate with the Department of Health at the University of

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Adelaide, ‘There may simply be a bias in the system because we rush off to the doctor and get the child tested but not the adult.’ Professor Cameron suggests two broad reasons why children are often more affected by certain pathogens. Firstly, there is the idea that everyone is exposed to these pathogens, and we develop a symptomatic illness at the time of first exposure when we are children before developing some kind of immunity that protects us later in life. Secondly, it may be that very young children are more likely than adults and older children to eat contaminated food. ‘Behavioural aspects make it more likely for one group to become sick,’ he adds. For example, it’s the child who is most likely to lick the cake mix out of the bowl, consuming some raw egg at the same time. Parents should also bear in mind that bacteria survive and grow on the various bits and pieces of baby-feeding equipment, from bottles and teats to non-spill cups with narrow openings or plastic straws which can be difficult to clean. Often these things are not sterilised; they may even bounce around inside the nappy bag, picking up bacteria and microbes from all around. Little children also like exploring their environment, thereby exposing themselves to risks.

¥

Are we putting natural immunity at risk?

In the United States winter of 1997, seven children acquired a pathogenic strain of E. coli from a day-care centre in Spokane, Washington from playing with contaminated modelling clay, toys, sand and soil. Another pathogenic E. coli outbreak, this time in Atlanta Georgia, saw 26 children come down sick after playing in a pool at the local water park; one child developed kidney complications and died. A leaking nappy was suspected of being the source which introduced the pathogen into the pool. A current controversial hypothesis, under

investigation, is that by trying to rid our lives of the presence of bacteria, we risk reducing our immunity. This is perhaps merely the scientific community putting a gloss on what parents already know: if you send your young child to a pre-school or play group they will come home with all manner of colds and illnesses which somehow help the child grow up with a more robust constitution. The recent debate, however, has centred more on health problems which seem to relate to affluence and clean living. Public health authorities know that the rates of asthma, hay fever, childhood eczema and other allergies are generally increasing in developed nations such as Western Europe, Australia, Japan and the United States. According to the hypothesis, by cleaning up our immediate environment so thoroughly — with anti-bacterial surface cleansers, soaps and even anti-bacterial pillows — children grow up without the stimuli necessary to put their immature immune systems to the test. It is these tests, it is argued, which help determine whether in future a person’s immune system will respond to an allergen or toxin in a way which releases histamines inside the body. (Histamines trigger some very familiar side-effects, including itchy eyes, a runny nose and wheezy breathing.) It is an interesting proposition. If we are not exposed to a very wide range of bacteria and other micro-organisms at an early age, do our defence mechanisms properly develop allround protection techniques, or only a limited response to bodily threats? Are we cleaning ourselves, our homes and even our foods to the point of our own harm? Should we get up from in front of the television and spend more time outside, playing games, rolling in the dirt, swimming at the beach and socialising with a wide range of people? Perhaps it is true that the more we isolate ourselves from the environment, the more sickly we might become. Of course there is more to this issue than a single simple answer. We don’t really want to go back to experiencing polio, measles or a life-threatening bout of food poisoning. Nor

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should we ignore the role our genes play in determining our health and affinity for certain illnesses. Hopefully, further research will tell us how to develop our immune systems to their fullest potential.

THOSE WITH REDUCED IMMUNITY Vibrio vulnificus and the parasite Crypto sporidium, generally fairly harmless to a healthy person, could cause serious illness, perhaps even death, in a person with low immunity. People with low immunity include: children, pregnant women, nursing mothers, the aged, transplant recipients, those using immunosuppressant drugs to treat cancer or even asthma, people with HIV. It is recommended that people with low immunity boil all drinking and cooking water (on a stove or in a kettle without an automatic cut-off). One of the main reasons is to kill Cryptosporidium parvum, which is particularly dangerous for those with reduced immunity. Normally the illness associated with this protozoan runs its course of diarrhoea, weight loss and abdominal pain within two or three weeks. However, if a person has reduced immunity it can last twice as long or can even become a chronic health problem, with infection of the body’s organs and tissues. At present there is no known effective medical treatment to combat this illness. Cryptosporidium is found in the water supplies of many towns, cities and countries, particularly in developing nations but also, on occasion, in industrialised cities and towns. It was involved in the Sydney water scare of July-September 1998. (It is important to note that there are a number of different strains of Cryptosporidium, but not all strains cause illness. Some are pathogenic: others are not.) Because it is so common in places like Africa and Asia, it is believed to be a major cause of travellers’ diarrhoea. This protozoan is resistant to chlorine treatment (as used by

water authorities) and, thanks to its minute size, can evade all but the most sophisticated filtration systems. It is a risk for everyone – but a most particular risk for children, the elderly, people with HIV, those undergoing cancer therapy, and others with low immunity.

WHY ARE OLDER PEOPLE AT GREATER RISK? There are some ideas as to why we become more vulnerable to food poisoning as we move into old age. For example, an older person secretes less acid in their stomach when eating, and stomach acid is one of the tools our body uses to combat bacteria in food and drink. General immunity can go into a gradual decline too. Sometimes our senses deteriorate as we age, particularly our response to smell and taste. While this might mean we become more at risk of eating and drinking spoiled food (like sour milk) this should not be confused with any ability to spot food which might lead to poisoning or infection. Older people can also be at increased risk of foodborne illness for a whole range of social and economic reasons, including increased reliance (for the home-bound) on food prepared elsewhere and brought over, or from trying to save money by hanging onto leftovers or food past its use-by date.

PREGNANT WOMEN Listeria, in particular, is a dangerous form of food poisoning for anyone who is pregnant: the unborn child can be affected, and miscarriage can occur. Listeriosis can even be fatal to the adult. Sometimes the authorities issue specific warnings: the British Department of Health advises pregnant women not to eat pate while pregnant. For most healthy, nonpregnant adults, however, Listeria is not much of a problem.

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Viruses such as hepatitis A and hepatitis E, which can be foodborne, may cause a more severe illness in pregnant women, resulting in a high mortality rate. Figures for women in developing nations show death

rates of about 17 per cent for hepatitis A and as high as 33 per cent for hepatitis E. In developed nations the death rates would not be this grim, but the warning remains pertinent.

SUMMARY ¥ The elderly and pregnant women should be wary of foods like soft cheeses, pate and

coleslaw. ¥ Be particularly careful with foods like chicken for children under one year of age

because of the heightened susceptibility of this age-group to Salmonella infection.

¥ Raw meats are a special problem for those aged one to four years. ¥ Those with low immunity should boil their drinking water.

CHAPTER

4

HOW DO I PROTECT MYSELF, MY FAMILY AND FRIENDS? GENERALLY SPEAKING, PEOPLE WHO ARE STRESSED, OVER-TIRED, RECOVERING FROM ILLNESS, AS WELL AS THE VERY YOUNG AND THE ELDERLY, ARE MORE SUSCEPTIBLE TO FOOD POISONING AND FOODBORNE ILLNESS THAN ARE HEALTHY PEOPLE. Maintaining your good general health is your first line of defence. This involves: ¥ having a proper diet ¥ drinking plenty of clean water ¥ getting adequate rest and recreation ¥ getting regular exercise ¥ breathing clean air ¥ having a positive attitude on life.

HOW YOUR BODY PROTECTS ITSELF Our techniques and tricks for making food safe to eat are only part of the equation. Indeed, the most spectacular defences occur naturally, within our bodies. The body’s first line of defence is the acid in our stomachs. Stomach acid, which is typically around a pH of 3, kills many harmful bacteria before they reach the intestine where they find more favourable conditions for growth. On the other hand, fat in fatty foods like chocolate can help protect bacteria from stomach acids, thereby letting them make their way to the intestine where they grow. The use of antacid medicines, or simply having a lot to drink with your meal, can dilute stomach acids and lead to the same result.

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Cold storage merely buys you time: not safety!

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Another line of defence is the multitude of harmless bacteria which naturally live in our digestive system. These bacteria compete for available nutrients and thereby limit the growth of any pathogenic bacteria, which then die off or pass out of the body before they get a chance to multiply and cause problems. The use of antibiotics can lead to a reduction in the levels of good bacteria in our digestive system and thereby make us more vulnerable to food poisoning for a few weeks after taking the treatment. This is where eating a ‘probiotic’ food, such as a yoghurt containing live bacteria, may help build up the numbers of good bacteria and increase our resistance to food poisoning. This practice is particularly beneficial when recovering from illness, or before going overseas. Some bacteria multiply to large and harmful numbers once they reach our intestine: for example, Salmonella typhi (which produces typhoid fever) and Vibrio cholera. One of the body’s defences to such bacteria is the production of white cells which consume and destroy the invaders. White cells are also an important defence against food poisoning caused by viruses. The immune system also produces antibodies which destroy the virus particles. Some of the symptoms traditionally associated with food poisoning — vomiting and diarrhoea — are mechanisms used by the body to rid itself of toxic substances before too much poison has been absorbed. And they act quickly to move large volumes out. The liver is another major player in our defence against toxins such as pesticide residues, or chemicals such as lead and arsenic which may be in our food and drink. Once these chemicals have been absorbed by the body they generally pass to the liver where they are ‘detoxified’, or converted to a form which can be excreted from the body in urine or faeces.

In some instances, such as where ‘heavy’ metals are involved, the detox i fi c at i o n process transports the element to your hair, where it can be stored out of harm’s way until the hair falls out or is cut. It becomes, in a way, geographically isolated.

FOOD STORAGE, PREPARATION AND PRESERVATION Living in a developed nation it is easy to gain a high level of protection against food poisoning and food intoxication. Of course, you can never have foolproof protection from foodborne illness, but you can get a long way by learning the rules. Here we will run through what works and what doesn’t to solve the problems.

¥

Cold

¥

Heat and cooking

Freezing will not kill bacteria, but it will stop them growing and reproducing, holding them in a kind of limbo. How cold is cold enough? You need to keep food at a temperature below 5°C (40°F) in the refrigerator or below –18°C (0°F) if it is to be put in the freezer for longer-term storage. Of course, this means you have to be careful when you take food out of the fridge or freezer as it might contain bacteria just waiting for the right temperature and conditions to multiply rapidly. Cold fixes nothing and makes no food safer than it was when it first went into the fridge or freezer.

Cooking is perhaps our number one home protection. Cooking (to a sufficiently high temperature and for a sufficient period of

TIP

Cooking is your most important ally in the fight against food poisoning. It is not the perfect answer for all situations, but it deals effectively with most of the common problems.

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time) will effectively kill a whole host of organisms and viruses contaminating food, including: Salmonella, Campylobacter jejuni, Clostridium perfringens, Clostridium botu linum, Cryptosporidium parvum, Giardia lam blia, Listeria monocytogenes, Staphylococcus aureus, Vibrio cholerae, E. coli, hepatitis A, Norwalk virus, yeasts and moulds. To kill yeasts and bacteria you must heat food above 60°C (140°F) for 15 minutes. Viruses can require higher temperatures still: at least 80°C (176°F). Many moulds will give up if heated above 60°C (140°F) for 10 minutes. Some bacterial spores may survive even hours of boiling, as in stews and soups for example. However, if you eat the soup soon after heating, the bacteria will not have sufficient time to become a problem. ‘Pasteurisation’ is a form of cooking used extensively in the food processing industry, particularly for dairy foods, canned foods and juices. Taking milk as an example, pasteurisation involves heating the milk to a high temperature (but not boiling) of at least 72°C (162°F) for 15 seconds (or a slightly higher temperature for a slightly lower time); the milk is then cooled quickly to below 5°C (40°F). Milk, even when pasteurised, needs to be kept in the refrigerator, as some bacterial spores and even some bacteria can survive pasteurisation. UHT milk is ‘ultra heat treated’ to 133°C (271°F) and then placed in a sterile pack. The packaging is a paper carton or plastic tub lined with polythene or aluminium to keep out oxygen and light. As a result of this process and care, a carton of UHT milk doesn’t need refrigeration until opened. But some organisms can survive attacks which would kill most others. For example, cooking will not always kill Bacillus cereus and Clostridium perfringens spores. Heat also has

little effect on toxins — it might kill the bacteria, but not the chemical toxins produced by those bacteria. Nor will heat destroy toxins produced by Staphylococcus aureus (that contaminates food by coughs and sneezes).

¥

Drying

¥

Salting

¥

Acid

Another method of control, without necessarily killing bacteria, is to dry the food. By removing moisture from the food it makes it hard for micro-organisms to grow. This is the process used for foods such as dried sultanas, currants, apricots and so on, as well as powdered milk and sun-dried tomatoes. Sugar, as used in jams and fruit preserves, also dries up any moisture. ‘Smoking’, where food is hung or paced on a rack over a smoky, wood fire, is another traditional technique for dehydrating meat and fish.

Salting is one of the very oldest forms of food preservation. It is often used in combination with drying the food, as is the case with dehydrated and salted meats like beef jerky. By reducing the available water, we make it difficult for bacteria, yeasts and moulds to grow. However, certain lactic acid bacteria, yeasts and moulds can either tolerate or adapt to moderate salt levels and still grow, causing food spoilage. Salting generally does not kill bacteria, so salted, raw foods should still be cooked before eating.

Acid foods (measured as a low ‘pH’ value) also make it difficult for organisms to grow and multiply. Manufacturers will often use vinegar or citric acid to turn foods from alkaline or neutral into a more acidic pH.

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Don’t think food is safer because it is spicier. Curries are safer from the long cooking time, not the spices.

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¥

Spices

¥

Alcohol

¥

Artificial preservatives

In the main, spices do little to preserve food, acting primarily to overpower any unpleasant tastes that might develop as the food gets older. However, some traditional spices, including chilli, cinnamon, cloves, garlic and mustard seeds, do have a mild preservative action.

Alcohol is a preservative. You might have seen fruit, such as prunes, kept in a jar with alcohol: it imparts the flavour of the liquor as well as preserving the fruit. Fruit cakes and Christmas puddings also benefit from a little alcohol, although the cooking (heat) and high sugar content (from the dried fruits) also play a part.

One of the common and best-known artificial preservatives is sulfur dioxide. As used with foods from prawns to dried apricots and wine, it is a very effective preservative, but people who suffer from asthma may be unlucky enough to experience an asthma attack brought on by eating food, or opening a container or pack of food, preserved using this compound. Many salamis use nitrates and nitrites as preservatives and to give a pink colour (they can also be part of the ‘curing’ process for hams). Some artificial preservatives have little or nothing to do with making food safe: rather, they are used to maintain a desirable and attractive taste, texture and appearance of the foods over the long period from processing to eventual consumption. Many consumers, however, would rather not have some of these arguably unnecessary additives. In some cases people have found their health — or the health or behaviour of their children — has improved once artificial additives are removed from the normal diet.

When you eat, do you sometimes feel discomfort and bloated with gas which smells like rotten eggs? Gail Vines, in ‘A Gut Feeling’ in New Scientist for August 1998, reported research, by John Cummings and others at the Dunn Nutrition Unit, Addenbrooke’s Hospital, Cambridge, looking at a harmful role for sulfur dioxide. This research indicated that diets high in sulfurous compounds — lots of meat, take-away foods, beer, wine, cider, dried fruits and many other processed foods — can encourage bad bacteria to flourish in the intestine, pushing aside the essential good bacteria we need to generate protective substances. The suggestion is that some gut disease and illness, from colitis and Crohn’s disease to irritable bowel syndrome and possibly colon cancer, might be encouraged, maintained or at least not prevented by these bacteria. Research continues in this area.

¥

Ultraviolet light

¥

Irradiation

Ultraviolet light is a purplish light from one end of the light spectrum: look for it above the rows of ham and sliced meats in your delicatessen. It is of limited use, but will kill some bacteria on the surface of foods hit directly by this light. It is used effectively against Listeria monocytogenes.

Radiation kills living things, including bacteria and insects in food, and can stop them reproducing. This is the simple idea behind the process of irradiation using the radioactive element cobalt 60. It can be used on dried foods such as rice and spices, some meat (hamburger mince), chicken, prawns and some fruit and vegetables such as strawberries and mushrooms. While food irradiation is not permitted in Australia at present, some imported foods, such as certain prawns and spices, may have been irradiated.

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¥

Vacuum packing

¥

Antibiotics

¥

Genetic engineering

Vacuum packing is one way we make life difficult for those types of bacteria which require oxygen. When some foods are canned, the air is sucked out of the container just before the lid is sealed. In the canning industry, heat treatment usually follows, and the sealed, airless can is heated to a high temperature. Foods are also sealed in plastic bags, then vacuum packed.

Just as we use antibiotic medicines to stop the spread of a bacterial infection in our bodies, so do food manufacturers in their foods. Cheese and crumpets, for example, rely on the antibiotic Nisin.

Although not necessarily an aid in the fight against food poisoning, researchers have found they can extend the shelf-life or improve the transportability of certain foods

by changing the genetic make-up of food. For example, a gene from a particular type of fish can be used to keep tomatoes firmer and better able to withstand the rigours of handling and delivery. This process upsets many consumers on many fronts. If you are a vegetarian, it may concern you that vegetables may be produced which rely on genes taken from animals. For some it is an issue confronting their religious beliefs, ‘interfering’ with nature, or eating genes from forbidden food sources. We really have no certainty about the outcome of manipulating genes across different species. Of course, there has always been a degree of genetic ‘manipulation’: farmers choose seed which delivers a better or more disease-resistant crop; animal breeders actively promote breeding between stock which demonstrate desirable characteristics, from the speed of a racehorse to the drought-resistance of cattle. Chicken growers have developed a chicken with a larger volume of breast meat. But is this the same thing as genetic engineering of food? (See Chapter 20.)

AU S T RAL I AN CODES FOR COMMON FOOD ADDITIVE S Numbers

P re s e rv a t i v e

W h e re it is found

200 to 203

Sorbic acid and sorbates

Bread, cheese spreads, cottage cheese, dried fruits, fruit juices, processed cheese, soft drinks, wine

210 to 213

Benzoic acid and benzoates

Cordials, fruit juice, soft drinks

220 to 224

Sulfur dioxide and sulfites

Dried fruits, dried vegetables, gelatin, meats (uncooked), prawns/shrimp (uncooked), soups, wine

234

Nisin (an antibiotic)

Cheeses, soups, canned tomatoes, crumpets

249 to 252

Nitrates and nitrites

Meats, salami

260

Acetic acid

Cheese, chutneys, pickles, sauces

280 to 282

Propionic acid and propionates Bread and other flour products

300

Ascorbic acid (vitamin C)

Breakfast cereals, juices

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RECOGNISING FOOD ADDITIVES Where food products have labels, the identification numbers of all additives must be shown in the ingredient list. However, we often buy products in bulk, prawns or sausages for example, where there is no label. With or without labels, you can be sure additives are widely used by the food industry, sometimes

specifically to try and protect us from food poisoning. On the previous page is a list of common additives in current use which are designed to address the problems of food spoilage and foodborne illness, with their Australian numbers. In Europe the numbers are generally the same (the Australian system was adopted from there), but the letter ‘E’ is placed before the number: for example, E220. In the United States the name of the additive is

spelled out.

SUMMARY ¥ Keep yourself healthy: it is your first line of defence. ¥ Cooking is your best tool for making unsafe food safer. Cooking will kill many of the

most common food-poisoning and food-intoxication bacteria and viruses. ¥ Effective cooking is a combination of the right temperature and a sufficient amount of

time at that heat. ¥ If using a microwave oven you must leave the cooked food to ‘stand’ for some minutes

until it is cooked right through. Your oven’s instruction book will tell you the necessary times. ¥ Cold temperatures merely buy you time: they don’t kill micro-organisms! ¥ Many other techniques are used by the food industry and by home cooks to control

micro-organisms. Often it is a combination of more than one technique that provides a high level of safety.

PA RT I I

A WALK THROUGH THE SHOPPING CENTRE

E. c ol i

salmonella

listeria

c ry p t o s p o r i d i u m

g i a rd i a

CHAPTER

5

THE DELICATESSEN

ROWS OF HANGING SALAMIS ABOVE YOUR HEAD, A DISPLAY CABINET FILLED WITH THE LUSTROUS PINK GLOW OF SLICED HAMS, CORNED BEEF, SLABS OF CREAMY PATE AND FIFTY DIFFERENT REMARKABLE CHEESES, JARS OF PICKLED VEGETABLES IN OIL STANDING IN COLOURFUL ROWS AGAINST THE BACK WALL. Welcome to the delicatessen! Whether you shop at a small family-run delicatessen in a crowded little store, or the long counter of the supermarket deli section, you will be faced with choices not only of what will taste good but what foods might put the health of yourself and your family at risk. Yet despite the bad publicity for deli meats, in particular, over recent years, the industry in Australia sets and maintains high standards. In reality the risk of food poisoning from deli foods is small. But we now know just how serious the consequences are — especially for young children — when something goes wrong.

At the heart of the matter is the unavoidable fact that many deli foods start out contaminated with dangerous micro-organisms. We rely on processing by the manufacturers to remove those dangers — sometimes traditional, age-old techniques are all that is required — and on distributors and retailers to store and handle these susceptible foods with appropriate care. You, too, play an important role in delivering these foods safe to your table. The first step in improving your level of safety is to know where the dangers are to be found. In this chapter we will look at delicatessen foods: ¥ smallgoods ¥ herbs and spices ¥ herbs and vegetables in oil ¥ dairy foods ¥ jams and preserves ¥ pate.

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SMALLGOODS

has made it into our food. We must rely on the right steps being taken in the manufacturing and food-growing processes. Smallgoods are not usually regarded by many In general, cooking is one of the great as ‘healthy’ foods! From a healthy eating point techniques at our disposal to make foods safe of view, they are generally high in undesirable to eat. In the deli we run into this problem: things such as fat, salt, cholesterol, and artifit y p i c a l l y, salamis and ‘dry sausage’ products cial additives. Yet we love their savoury taste are not cooked (at least not enough to kill and chewy texture, from the spicy salami to bacteria) during manufacture or before being the sweet honey-cured ham. Above all, they e aten. Pro d u c e rs rely on a number of other are convenient foods, used in sandwiches or f a c t o rs and processes for preserv ation, on a plate, to make a quick and satisfying including drying, salt, curing, smoking, artifilunch or dinner antipasto platter. But they can cial additives (such as nitrites and nitrat es), also provide the nutrients for the growth of increasing the acidity by ferm e n t ation, or by food poisoning bacteria such as Salmonella, E. p a s t e u r i s ation. These processes are also gencoli and Staphylococcus aureus. Staphylococcus aureus is one of the most erally not enough to kill bacteria. Rather, they common causes of food poisoning in our soci- slow their growth down to acceptable levels ety. It doesn’t mind salty foods like ham and within the shelf-life of the product. It is not necessarily the case that all of other deli meats; it can also deal with sugary foods, and the curing process, and prefers these techniques are used. Ham, for example, foods with a neutral to slightly alkaline pH. relies on salting, smoking or drying; sodium We humans seem to be more sensitive than nitrite is added as a preservative and to keep a pink colour to the meat. Fancier deli meats also our pets to this one. use spices. For example, prosciutto (Parma Of the main ways that bacteria get into ham) is ham which has been rubbed with a mix our food and have the opportunity to produce of sugar, salt, pepper, spices such as nutmeg, their toxins (outlined in Chapter 1), Staphy coriander and mustard, and preservative lococcus aureus is generally passed in two ways: nitrates, before undergoing a steaming process. Corned beef is silverside beef treated with a ¥ the hands. It is estimated that 70 per cent of the population carry this bactebrine solution with added sodium nitrate as a ria. A person will get the bacteria on preservative. Bacon is a fatty cut of pork, their fingers when they touch their nose, cured traditionally by salting which draws fiddle with their earrings, touch pimples, moisture out of the meat, leaving bacteria to burns or cuts, or whatever. Wiping your dehydrate and die. These days sodium nitrate is running nose with the back of your hand the main preservative, with salt added more is no protection! From the hands it is a for the point of taste than action. short step to food which is being preSome smallgoods are cooked to kill harmpared. ful micro-organisms, but cooking changes the taste and texture of the food. A major alter¥ cross-contamination from kitchen surnative to cooking is fermentation. Fermentafaces and chopping boards. tion uses helpful bacteria to create acids, Staphylococcus aureus can also be found in thereby making the food more acidic, which untreated milk which has come from a cow helps prevent the growth of pathogens and which helps kill off any harmful microbes with the udder infection, mastitis. Heating generally kills the bacteria, but it which were in the raw ingredients (such as produces a toxin which can survive boiling. Salmonella in the living chicken). FermentaThis means we are in trouble once the toxin tion is a very common protection process

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VOOD OO MAGIC FOOD across the world: in Germany, for example, around 25 per cent of the typical diet involves fermented foods. Fermentation takes a set of raw materials — such as meat, fat, cereals, vegetables,herbs and spices — and turns them into sausages and other foods which taste and smell quite different. They are tastes and aromas which many people love and which cannot really be duplicated by other methods of processing. But fermentation can lead to real problems if the correct procedures are not followed (see ‘Salami on trial’, on page 49). The first outbreak of E. coli O157: H7 arising from consumption of dry, cured salami and sausages in the United States, took place as recently as December 1994. The contaminated salami and sausages, manufactured in California, affected both adults and children. It is not always obvious that a food has been fermented and, if so, whether it should be stored in the fridge or on the shelf. Where do you keep your bottle of soy sauce, for example? Get it out and take a look at the label. Many brands say to ‘Keep refrigerated once open’. Some tomato sauce is the same. The following deli foods rely on fermentation: ¥ many dry sausage products

(e.g. salamis) ¥ sauerkraut (fermented white cabbage) ¥ many soy products, including cheese

(‘sufu’) or yoghurt styles, tempeh, natto and miso ¥ soy sauce (shoyu) and tamari ¥ beer, wine and other alcoholic beverages ¥ dairy products such as yoghurt,

cheese and butter ¥ olives ¥ idli (an Indian food based on cereal and

legumes, and similar to sourdough bread) ¥ many preserved vegetables

(picked, bottled).

Fermentation, as a process for making food safe to eat, goes back a long way. One of those foods which people either love or hate — fermented cabbage or sauerkraut — was described in ancient Rome, around the first century AD. Each time the Romans wanted more of this pickled cabbage they would chop up the vegetable and put it into earthen vessels set aside for this purpose. It is believed the bacteria which fermented the cabbage settled into tiny holes in the inside walls of the jars, passing from one batch of cabbage to the next. African ‘witch doctors’ may also have used a similar trick when creating the alcoholic brews used in their ceremonies. According to Herbert J Buckenhuskes, the medicine man dipped cult objects into the liquid which contained micro-organisms from the previous batch. And so the ‘inoculum’ would be introduced to an otherwise unremarkable fruit or vegetable concoction. No wonder these people and their tools were thought to be magic!

As well as fermentation it is common to see salt added. The sausage (or sliced meat product) might also be dried in other ways, such as by storing the food at 10–15°C (50–60°F) under conditions of low relative humidity. If the sausage is dried too quickly the meat and casing can go hard, making the food less enjoyable to eat. In Canada and the United States it is also common to take the dried sausage and heat it to 55–60°C (130– 140°F), adding yet a further processing stage to control bacteria and, as an additional benefit, making the sausage easier to slice. In producing sausages there are several steps in the processing designed to make the food safe to eat. This reflects the number of risks. If the processing is all done correctly, we end up with a tasty, not-too-dry sausage which is safe to eat and which has the great feature of not requiring refrigeration. But, as you can see, we rely on a whole series of

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steps to keep the bacteria and microbes in check. If there is a failure along the processing chain, then the pathogens will flourish at the delicatessen before you buy the sausage or in your pantry. However, cooking a meat product is a simpler way of producing a safer sausage, and you may prefer to steer towards the cooked sausage and sliced meat products. However, the cooked meat products will not deliver the same intense tastes and aromas as the fermented ones.

¥

Salami on trial

The largest outbreak in Australia of a particularly harmful strain of E. coli in delicatessen foods occurred in South Australia in 1995. It is alleged by health authorities that the manufacturer, Garibaldi, did not successfully ferment its mettwurst (an uncooked, semi-dry sausage which requires fermentation to inhibit harmful bacteria). There are several ways of fermenting a meat product, but the one which is understood to have been used by Garibaldi was a process called ‘backslopping’. This requires the presence of the right bacteria to start the f e rm e n t ation process. If you are making yoghurt at home you can start the thing off with a spoonful of a commercial yoghurt which brings the necessary bacterial ‘culture’ into your fresh batch. With backslopping some of the previous batch is used to start the fermentation of the next run. This process is risky because any contamination of the stored ‘slop’ can pass on to future batches, contaminating them instantly. Small amounts of very dangerous bacteria can quickly multiply while sitting around waiting for the next batch to begin. Suppose the manufacturer mixes up his salami or sausage in a large 10,000-litre vat. When he finishes one batch he might retain 10 per cent of the liquid to start off the next batch. The problem is that once a food poisoning micro-organism begins to grow it continues to multiply in the remnant, and contaminate

the whole batch. If the bad bacteria grows faster than the others the manufacturer is in big trouble. A remnant will continue for batch after batch from that time on, multiplying until it reaches a level, after many days, where it becomes a health hazard. The culprit in the Garibaldi case was a particularly potent and dangerous type of E. coli known as serotype O111. Only about a dozen individual cells are needed to infect a susceptible person. Once inside the person’s digestive system, this bacteria competed very successfully with other harmless E. coli in the gut and was able to grow to sufficient numbers to poison people. In this case it was an outbreak of what is called haemolytic uremic syndrome (HUS), a severe form of food poisoning which produced bloody diarrhoea and kidney failure. This was the largest reported case of food poisoning by this particularly dangerous strain of E. coli. An outbreak was reported in Italy in 1992 where nine patients developed HUS attributable to O111, and there was another outbreak in 1993. In the Garibaldi scare, 23 cases of HUS were diagnosed among children aged under 16 years. The median age was only four years, with the youngest victim only four months old. Sixteen people required dialysis for their damaged kidneys and one four-year-old child died. Many other people who went to doctors or hospitals complaining of gastrointestinal illness at that time were found to have eaten the sausage in question, although they did not develop the serious illness which affected the worst cases. It is remarkable that children were most affected, not adults. As a consequence of the 1995 outbreak, backslopping has now been banned in Australia. Food manufacturers must use a starter bacteria culture of known, certified bacteria and keep the product at or above a certain level of acidity in order to limit the growth of bacteria. A further requirement is that manufacturers of smallgoods must monitor the moisture level in their products, ensuring that the

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50

level doesn’t rise to a point which makes life easy for the bacteria. At present there is no feasible test that manufacturers of fermented sausage can use to detect the presence of E. coli O111. However, the same precautions which are used to protect food from other types of E. coli and Salmonella should be sufficient to knock out the threat of O111 poisoning. And while backslopping has been banned in Australia as a food inoculation technique (where it is relied upon as the sole means of initiating fermentation), it is still in use in many other parts of the world for foods such as dry sausages and salamis, and sauerkraut. In Australia there remains some expert concern that not all manufacturers will abandon the old ways, whether because they want to save money or they feel the technique adds to the unique taste of their products. It will be up to the food inspectors to keep an eye out for this, and the Australia New Zealand Food Authority has introduced food hygiene standards for manufacturers of fermented meat products.

¥

Deli meat additives

When meat decays it changes colour, from pink and red to grey or brown. Food manufacturers have found a set of additives which help maintain a pink colour in meat, as well as having the advantage of acting as preservatives and flavouring agents: these are nitrates and nitrites. Sodium and potassium nitrate or nitrite are used in ham, bacon, salami, sausages, corned or picked beef and other pink deli meats. Here, again, is cause for concern. Down in your stomach, the nitrites can combine with substances called ‘amines’ (amino acids), which are produced naturally in the stomach and as a result of digestion. Put them together and you form ‘nitrosamines’ which are potentially carcinogenic compounds.

Don’t panic! Experts say you would need to be eating a lot of smallgoods regularly if this was to become a problem. But what if you are hooked on them? Not all of us react well to the nitrites in deli foods. Some people complain of headaches, eczema or asthma caused by the nitrites, so watch for these symptoms in your family. On packaging and labels you can detect if nitrates or nitrites have been added by looking for the additive numbers 249 or 250 (nitrites), 251 or 252 (nitrates). By law, in Australia, food cannot contain more than 500 mg per kg in total (0.05 per cent) of nitrites and nitrates. Sulfur dioxide is another common preservative found in salamis and deli meats (as well as soft drinks, beer and wine, fruit juices, dried fruits, potato crisps and vinegar). On labels, sulfur dioxide and other sulfites bear the additive numbers 220 to 224.

¥

Exposure to air and handling

It is common that your deli counter will be a refrigerated display case containing mostly sliced meats. They might be there for day after day, until someone buys them. Therefore, when you are at your deli, look for signs of trouble: ¥ Is the display case refrigerated? It

should feel cool to touch and you may be able to see air vents, pipes or even a temperature gauge. A deli fridge should be set at or below 4°C (40°F). ¥ Do they seem to pre-slice too much

meat? Are there huge piles of sliced meats and not many customers? ¥ Do the staff use tongs and plastic gloves

when handling the meats? ¥ Watch out for avenues of cross-conta-

mination. Do they use the same tongs for

TIP

There is evidence to suggest that vitamin C acts to prevent nitrosamines developing in your stomach when you eat bacon and similar foods, so take a glass of orange or tomato juice with your bacon and eggs or ham sandwich. It might help.

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a range of products, or does each product or set of products have its own tongs (e.g. one for the hams)? Do they place the sliced meat directly onto the scales, or is there a layer of paper or plastic between the scales and the food? ¥ Do they keep the doors to the cabinet

closed when they are not actually reaching inside to fetch something, or are the doors left open? ¥ Are there flies inside the cabinet?

¥

The incomplete label

Deli foods have many potential risks, yet their labels (if present at all) are unhelpful for consumers wishing to know the risks. It would be best if the product label told you: ¥ what was in the product: the meats,

cereals, stuffing and so on ¥ what methods were used to make it

safe: cooking, curing, etc. ¥ what type of casing was used: natural

pack sat in the back of your car or on the kitchen bench at room temperature. Food manufacturers are justifiably concerned about their legal liability if they give specific advice on the pack about storing the opened product. And there is no legal requirement that they do so. Unfortunately in Australia the food rules lack a uniform system for classifying smallgoods in a way that lets consumers know their contents and what type of process they have undergone to make them safe to eat. Some processes are safer than others. On the other hand, recent changes to the Food Code in Australia mean that smallgoods must indicate some types of protective processing. For example: ‘Fermented cooked’ or ‘Fermented — heat treated’. If a fermented manufactured meat product has not been cooked or heat treated, the label must say ‘Fermented manufactured meat — not heat treated’.

¥

Storage

Here are some tips for storing your deli meats:

or plastic ¥ how it should be stored ¥ how long it can be stored unopened, in

the case of nobs and sealed packs, or opened and exposed to the air. This last point is one where the manufacturers cannot win. It would be great to know how long you could keep a pack of ham, for example, once you opened it and used the first slice. Should it be thrown out after one more day in the fridge, or two days, or what? The problem is that once the packet has been opened there are many opportunities for things to go wrong in the consumer’s kitchen. The ham slices left in the pack could become contaminated from the knife which spread the butter, cut the bread, added the mustard and generally lay about on the bench. The storage time would also depend on the temperature inside the fridge and how long the

¥ Wrap a leg of ham in a dry tea towel or

linen bag. Return the ham to the fridge as soon as you have sliced sufficient meat for the meal. Change the wrap once each week. The ham should last up to three weeks. ¥ Assume all plastic packaging is dirty. Do

not rest the meat on the outside of the pack. ¥ Do not keep sliced deli meats in the

fridge for longer than the use-by date (or three days if there is none). ¥ Try storing a product like shaved ham in

the freezer. It is easy to cut off a chunk when needed (although it will not taste as good as the unfrozen product and you can expect to crunch on the ice crystals). A good tip is to use the frozen meat in a toasted sandwich, jaffle or other cooked meal, so it can warm up quickly.

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RULES FOR SMALLGOODS These are our ‘smallgoods rules’. They represent a conservative view, but are designed to help you understand the nature of these products and where the risks lie. Remember that, despite the risks, few people get really sick from these products in any country which has a food manufacturing industry with high standards. So, continue to enjoy these deli meats by all means. But look carefully at how you and your family handle these sensitive products at home. RULE

1 ¥

Favour cooked deli meats over uncooked ones

Generally, cooked deli products include Devon, Strasbourg sausage, Polish sausage, fritz, cabanossi or cabana, mortadella, and well-cooked roast beef (brown/grey in colour). They tend to be the ones with a finer, minced appearance: not the ones with visible chunks of meat, which are more likely to be fermented salamis. Those uncooked products which are more of a risk include: salami (Spanish, Polish, Hungarian, ‘hot’, ‘mild’and so on), pepperoni, and rare (pink) roast beef. Watch out for these in pizzas, especially the ‘supreme’ style which has a bit of everything, or anything called ‘meat’ pizza’. One to watch is rare roast beef. Here the pink colour indicates lesser cooking than where the roast beef is brown or grey in colour. The problem is that these light areas have not reached a temperature high enough to kill any harmful micro-organisms that may have been present. There is a second problem here. Juicier, wetter meats provide a better environment for micro-organisms to get around and multiply. It is easier for them to move throughout the meat when they can travel along rivers of moisture and, in a meat product, the juices are brimful with nutrients which the bacteria use to build themselves up to maturity. All in all, a drier meat is a safer meat.

RULE

2 ¥

The more ‘whole’ the product, the safer it should be

The general rule is that contamination is usually on the surface of a piece of meat and not in the muscle ‘belly’. Mincing, slicing and shaving expose more of the meat to the possibility of contamination (from hands, cutting boards, mincing machines, knives, etc.) The least physically processed (the top of the list below) are therefore the safer. So from safest to less safe: ¥ whole nobs of cooked meat, or whole

ham on the bone ¥ sliced fresh off the bone (Ask staff to

slice the meat in front of you.) ¥ pre-sliced, by the slice ¥ ‘shaved’ or diced ¥ meats which have been cut up or diced

and then processed and formed into nobs. RULE

3 ¥

The more processing and handling, the greater the risk of something going wrong This really covers Rules 1 and 2. Processing requires handling, and this is where mistakes can occur. Salamis are highly processed products, in this sense, because they can contain many ingredients, from fats and meats to cereals, spices and artificial additives; each of these offers an opportunity for contamination if handled incorrectly and thereby multiplying the risk. Many cooked meats also undergo a lot of processing and handling. RULE

4 ¥

Beware of what has been added: it can introduce its own problems Sometimes a completely different product is added to the meat to make a more interesting taste. However, this provides a major opportunity for infection. For example, mortadella,

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being a cooked meat product, is arguably one of the safer deli choices. But if you add olives or a ‘stuffing’ of some kind, there is a pathway for bacteria to come on board. A safer choice is mortadella without the extras. Similarly, spices and herbs can bring their own contamination to the meat. There is an argument that certain spices offer improved protection against bacteria, but this is uncertain. What is clear, however, is that some spices are contaminated with organism spores such as Bacillus cereus, which resist cooking and drying. RULE

5 ¥

Salty meats are safer choices

Ham and corned beef, for example, are safer choices because so much salt has been used in their processing. Honey-cured hams replace some salt with sugar. RULE

6 ¥

Natural casings are better than plastic

At home, take extra care with any large lump or nob of salami or deli meat which is encased in plastic, as opposed to a natural casing made from animal intestine or the like. If it comes in a plastic casing, as is often the case with something like Devon, take it straight to the fridge. On the other hand, a salami with a natural casing can be stored in the pantry for a few months. RULE

7 ¥

Keep all deli products in the fridge

Your sliced deli meats should always be kept in the fridge. If they are not eaten within two or three days, throw them away or feed them to your dog, not your family.

HERBS AND SPICES There are at least four ways we can buy our herbs and spices: ¥ fresh: as clumps or stalks of fresh herbs

from the market garden or your own garden. They dry out within a few days, fading and losing their taste and vigour. Keep these in the fridge. ¥ dried. Bottles and packets of dried

herbs and spices line the supermarket and deli shelves. They are convenient to buy, carry and store, but they really lack flavour of the fresh kind. Exposure to light, air and heat will further dull their taste, so store them in a cool, dry, dark cupboard. Keep herbs in a sealable container such as a bottle (one which previously held the same herb or spice). ¥ bottled fresh in oil. Basil, coriander, garlic,

ginger and chilli are popular household spices which can now be purchased ‘fresh in oil’ in the bottle. You can store the bottle for several months in your pantry if unopened. Once opened, the bottle must be kept in the fridge. ¥ frozen. The whole pack is designed to

live in the freezer compartment of your refrigerator. Each time you want some, you scoop a little out of the pack. Herbs and spices are generally no cause for alarm. However, some have been implicated in food poisoning scares. If you are facing a hot summer, keep chilli powder, cayenne pepper and paprika in the fridge.

¥

Herbs and vegetables in oil

Oils can also go off, becoming rancid, so check them occasionally for smell and any changes to the appearance of the oil or food. Keep the lid on the bottle or tin, store it in a cool, dark place and it should last for up to six months. Herbs in oils can be stored in the fridge.

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SPICY CHIPS Storing herbs and vegetables in oil is not necessarily a safe path either. Oil is not a preservative, though it slows discolouration of food by preventing oxidation from the air. Yet by excluding air, canning and preservation in oil can actually create conditions in the food which favour the growth of Clostridium botu linum and certain other types of bacteria. In fact the International Olive Oil Council recommends storing jars of mixed garlic and oil in the fridge for no more than 24 hours. Although the risk of food poisoning is small, there are certain bacteria which grow in the absence of air, and the oil provides a good cover. There can also be a problem with botulism. While mustard is an example of a herb which can sometimes kill harmful bacteria, the fact that herbs and spices, including garlic, have been added to some foods should not be seen as effective preservatives. If they have any preservative benefit, it is only slight. Devastating outbreaks of botulism occurred in the United States and Canada in the 1980s where the source was chopped garlic in oil. Botulism, though fairly rare, has a high death rate, so all cooks making home preserves must know the risks and how to work safely. In the United States and Australia, for example, it was decided that these types of foods should not rely solely on refrigeration for their safety. An additional precaution, now required commercially, is that the product must be acidic (the pH must be kept below 4.6). This is achieved by adding an acid like vinegar (acetic acid) to the garlic and oil. Sun-dried tomatoes are one vegetable which require little extra help. The drying process concentrates the natural acidity of the product, making them relatively safe from food poisoning bacteria. Other vegetables must be dried and rendered acidic if they are to be preserved.

Potato chips (or potato crisps) are a popular, salty snack food. And there’s little for us to worry about in their basic ingredients: potato, salt, sugar, oil. They are a dry food with a long shelflife. Yet even the humble chip can cause alarm. In Germany, for a period of six months from April to September 1993, an outbreak of salmonellosis food poisoning spread across the country. More than 1000 people, mostly under the age of 14, were affected with the illness. The cause, when tracked down, turned out to be potato chips. Well, not actually the chips, but the powdered flavouring which coated them. The flavouring contained paprika which had been contaminated with Salmonella. The German incident remains the largest documented outbreak of food poisoning due to a spice.

DAIRY FOODS Dairy foods are highly nutritious and, unlike smallgoods or many other deli foods, are an important part of our daily diet. We benefit from their calcium for our bones, from their protein to build up and repair muscles, and kids, especially, get the fat they need to fuel their energetic lives. Later in life this fat and cholesterol become less desirable and many dairy products have been reformulated to minimise this down side while still delivering the wholesome value. Yoghurt can also have positive health benefits in fighting foodborne illness, thanks to the particular bacterial ‘cultures’ used in some products (see Chapter 13). The problem bacteria for dairy foods are: ¥ Listeria monocytogenes ¥ Salmonella ¥ Campylobacter ¥ Staphylococcus

TIP

Fresh herbs can survive for several months in the freezer. Just slip them into a plastic freezer bag and seal the opening.

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¥ Clostridium

‘Unpasteurised’ cheeses have an image of being more natural products, reflecting their ¥ E. coli regional tastes, aromas and colours more ¥ Brucella melitensis (although brucellosis, vividly that those which have been heat-treatthe disease in infected cattle, is not preed as part of pasteurisation. While Prince sent in Australia). Charles has championed the cause of the unpasteurised cheese in his corner of Europe, Processes used to control contamination are: there is a similar movement in Australia, sup¥ pasteurisation. Milk for example is usuported by specialist cheesemakers. Maybe ally heated to 72°C (162°F) for 15 secone day we will see the law overturned and onds, then rapidly chilled to 5°C (40°F). unpasteurised cheeses will hit the deli shelves or become procurable at the farm gate. ¥ starter cultures. These compete with Meanwhile, if travelling overseas, check unwanted bacteria for all available nutridairy labels (of cheese in particular) to see if tion, keeping the bad ones in check to a the product has undergone pasteurisation. degree (for example, yoghurts). This is not to say that eating any and all unpas¥ raising acidity (that is, lowering pH) teurised dairy products will make you sick, but d ry i n g. This is used for hard cheeses like it is only fair that you should be informed ¥ Cheddar. about the higher risk. It is a risk you might be prepared to take as a resident of a particular ¥ ultra-heat treatment. UHT or long-life country, but one you might prefer not to take milk are products designed to be stored while on a brief holiday or business trip there. outside of the refrigerator, until such Pa steurisation is desirable because the time as the special packaging has been milking process often does not take place withopened. in a sterile environment. In fact we must In Australia all commercial cows’ milk assume there is always the risk of the milk cheese must be made using pasteurised milk: coming in contact with contaminants from aniit’s the law. However, in Europe cheeses are mals faeces, sometimes straight off the udder, commonly made from raw milk. And they pay and from the soil. Fortunately pasteurisation a price for it too. Europe is home to a wide inci- deals with this threat quickly and efficiently, dence of Listeria poisoning from dairy foods, but not always. There are reported cases from with 96 deaths and more than 7000 reported Britain of food poisoning where the pasteurisacases of food poisoning from cheese products tion process was not carried out properly and over the 15-year period from 1983 to 1997. the heat treatment was inadequate (it requires We only have to look at the raw material a degree of skill and good equipment to get it to understand how this can happen. A survey right). And there are pressures to minimise the in 1992–93 of raw milk in farm bulk tanks in heat treatment, either a lower temperature or England and Wales found Salmonella in 0.36 the duration of heating, as the heat affects the per cent of samples; and Listeria monocyto - texture and taste of the food. genes in 5.08 per cent. Another survey found Still, how often do we now hear about E. coli (indicative of faecal contamination) in those common nineteenth-century milk-borne 62 per cent of samples. diseases: bovine tuberculosis, brucellosis and The issue is not dead in Australia either. typhoid fever? TIP

Foods which are chock-full of nutrients are not only good for us, but are just what bacteria need if they are to grow and reproduce. Pure water, by contrast, makes a poor home for bacteria as there is very little in the way of nutrient value floating by.

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SAFER + RISKIER CHEESES As good as it is, pasteurisation is not always a perfect solution. While pasteurisation kills common pathogenic bacteria in milk, including Listeria, it also destroys naturally occurring antimicrobial factors in milk. This means that if pasteurised milk is exposed to contamination during subsequent handling there is now more of an opportunity for bacteria to grow. Thus milk products which receive a lot of handling after pasteurisation (cheese, for example) retain a risk of Listeria poisoning. The risk would still be there if unpasteurised milk was used, but less likely. The bottom line is that we cannot depend completely on pasteurisation. It is important to continue to have hygienic handling and correct refrigeration and storage after pasteurisation. Behind the scenes there are pressures for change. Food manufacturers are always on the lookout for new markets and new products. When it comes to dairy foods we are witnessing the introduction of what might be called ‘exotic’ milks: not just from cows and goats but from sheep, and even buffalo. This might be great for the taste buds but it also means we are likely to be exposed to new or at least different bacteria and other pathogens. Bacteria, and moulds, also love cheese and yoghurt. Many moulds produce their own poisons which dissolve in these dairy products and diffuse to far-flung corners without showing any visible sign on the surface of the cheese or yoghurt. The key thing to know is this: soft dairy products are more of a problem than hard ones. The soft texture means there is more moisture in the food, and this aids bacteria and moulds. Hard cheeses are drier and the contamination process takes longer to reach a dangerous level. For the same reason, it can be possible to salvage parts of a hard cheese which shows mould, when a soft cheese should simply be thrown away. Cut a couple of centimetres away

LO W E R-R I S K C H E E S E S Cheddar P a rm e s a n Edam Swiss highly pro c e s s e d cheese, such as cheese sticks

HIGHER - RISK CHEESES Brie C a m e m b e rt m o z z a re l l a G ru y e re ricotta cottage cheese

from the mouldy part of your Cheddar or similar hard cheese and you will generally be OK, although there is still a degree of risk because soluble toxins slowly migrate through the cheese. Some cheeses, of course, are created to display particular types of mould which impart strong tastes and textures. Examples include: Brie, blue vein and Camembert. There are others which might appear at first glance to be infected with mould but which are quite safe. The colour may come from having dipped the cheese in port wine or some other liquid. Generally, pasteurised milk, cheese and butter are safe products, so don’t get too concerned about the dangers along the manufacturing road. However, the very nature of the process means that a slip in the way dairy products are transported, stored or displayed, or carelessness at home will allow the bacteria and moulds to be off and running. Get your dairy products into the fridge fast and keep them there!

JAMS AND PRESERVES What have we done to jams and preserves that enables them to last for so long open and out of the fridge? There are three factors at work here: ¥ fruits are acidic ¥ we add sugar and, in some cases such

as pickles and chutneys, salt ¥ we cook them.

TIP

When safety is a concern, choose the hard cheese ahead of the soft cheese.

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All three measures make life hard for the bacteria and micro-organisms. Bacteria like being in a wet environment as this helps them move throughout the food and multiply easily. Sugar and salt pull moisture out of circulation in the food, inhibiting bacterial growth in an age-old, simple and natural way. Yet as ‘natural’ as jam may be, current fashions for low-salt, low-sugar, no artificial preservative products can only increase the food safety risk in jams and preserves, unless other techniques are used in their place. Watch out also for what you bring to the jam on your knife or spoon. This is a potential pathway of cross-contamination into an otherwise very safe food.

In Australia, the Consumers’ Association has tested samples of pate purchased from shops. Reporting the test results in its magazine, CHOICE, it has found, over the years, the presence of disease-causing organisms — E. coli, Salmonella and Staphylococcus aureus — and conditions favourable for their growth or the growth of Listeria monocytogenes. Check the use-by dates. Pate has particular risks because of a combination of factors that enable bacteria to thrive or arrive through handling errors: ¥ it is high in protein ¥ some of the meats used in pate, such as

liver, are only partially cooked ¥ in mincing the meat to form paste, large

PATE

surface areas are left exposed to air and possible contaminants

Pate is a product to watch. It is a paste make from meats, fish or poultry, flavoured with herbs, spices, alcohol, fruit or vegetables. One of the most famous pates, pate de foie gras, is made from the livers of geese and ducks which have themselves eaten a special fatty diet. Similar products include liverwurst (a pork-based paste which generally uses less liver than does pate) and terrines (which have a coarser, sometimes layered, texture). You can buy pate in a fresh form (which must be refrigerated!) and in tins or jars, which can be stored in the pantry until opened. In 1989 some pate being imported into Britain was found to have high numbers of Listeria monocytogenes, and it was withdrawn from the market. Following this discovery, the British Government’s Chief Medial Officer issued a warning that ‘vulnerable people’ should avoid soft cheese and pate, and regulations covering temperature control of soft cheese in England and Wales were made more stringent, leading to a considerable reduction in reported cases of listeriosis. TIP

Be wary of home-made pate and terrines.

¥ pates are often decorated or placed in

their containers by hand. Such handling might take place after the pate has been cooked to kill the bacteria, leaving a door open for contamination. Sometimes the manufacturer adds a preservative (such as sulfur dioxide or sodium nitrite) to slow down the growth of bacteria. In Australia there is little evidence that commercially produced pate presents a great health risk. The important point, however, is to recognise that pate and terrines are types of product which require extra care, from those who produce, transport and sell them, and by the consumer who brings them home. When making them yourself, keep your raw materials refrigerated and be aware of opportunities for cross-contamination in the kitchen. Take extra care at every step and ensure the mix stays in the fridge when not actually being served. If you are at a picnic and pate or terrine has been out in the sun for a few hours, give it a miss.

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SUMMARY S M AL L G OODS ¥ When in doubt, choose ham or Devon. ¥ Favour cooked deli meats over uncooked (fermented) ones. ¥ The more ‘whole’ the meat product, the safer it should be. ¥ The more processing and handling has gone on, the greater the risk of something

going wrong. ¥ When one food has been added to another, such as a stuffing, the added food can

introduce its own problems. ¥ Salty, dry meats are better choices than moist, less salty ones. ¥ Keep all smallgoods in the fridge. ¥ Don’t eat anything which is past its use-by date.

HERBS AND SPICES ¥ These pose minimal risks.

HERBS AND VE G E TABLES IN OIL ¥ These have a long life in the fridge, but watch for signs of oil turning rancid.

DA I RY FOOD S ¥ Pasteurisation is vital (and required by law in Australia). Beware of unpasteurised

dairy foods, especially when travelling overseas. ¥ When safety is a concern, choose the hard cheese ahead of the soft cheese. ¥ Cut the mould off a hard cheese: but throw away a soft cheese which shows any

sign of mould. ¥ Keep all dairy products in the fridge. ¥ Don’t eat anything which is past its use-by date.

JAMS AND PRESERVE S ¥ These pose little risk, apart from cross-contamination from your knife, spoon or cut-

ting board.

PAT E ¥ Handle and store with great care. ¥ In particular, be wary of home-made pates and terrines. ¥ Keep them in the fridge. ¥ Don’t eat anything which is past its use-by date.

CHAPTER

6

THE GREENGROCER’S SHOP

THE GREENGROCER’S SHOP — WHETHER A SHOP ON ITS OWN OR PART OF A SUPERMARKET — OFFERS SO MANY OF THE FOODS WHICH ARE DESIRABLE FOR OUR GOOD HEALTH. Although this is not a book about nutrition, it is worth noting just how important fruits and vegetables are in our diet. Vitamins remain in fairly good condition while the fruit and vegetables remain uncut or unopened to the air. Once exposed to oxygen in the air, enzymes start chemical reactions which change the texture and taste of the food, as well as causing the nutritional value to decline. The health problem with fruit and vegetables is a simple one: much of what is grown in the fields has had some contact with animals and the bacteria they carry, as well as soil organisms. The sources of contamination include: ¥ soil ¥ the use of manure-based fertilisers

¥ run-off from pastures where animals

have been ¥ irrigation using sewage-contaminated

water ¥ farm workers – pickers and packers –

who don’t wash their hands after going to the toilet. What we might also fail to realise is that fruit and vegetables endure an enormous amount of handling between the paddock and the plate. In the fields asparagus is harvested one piece at a time, each stem cut by a handheld knife. Later on those asparagus spears are placed in containers by hand. Peaches, grapes, cherries … most of our fruit is picked by hand and displayed for sale where consumers are handling it. There are also plenty of opportunities for contamination from the soil, the pickers and the process workers, as well as for damage to occur thanks to rough handling or from mechanical means which break through the protective skin of the fruit or vegetables.

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FRUIT AND VE G E TABLES: THE GOOD THEY BRING BENEFIT Fibre Vitamin C Vitamin E B group vitamins Vitamin K Beta carotene (vitamin A) Potassium Folate Iron Starch Water Sugar (fructose) for energy Kilojoules Fat

EXAMPLES apple, carrot, peas, broccoli, beans, prunes, passionfruit, dates, kiwi fruit lemon, orange, paw paw, guava, kiwi fruit, beans avocado, lettuce beans, peas, chilli, corn, parsley, mushrooms spinach, cabbage, cauliflower, mushrooms tomato, broccoli, pumpkin, apricots, carrot, spinach banana, Brussels sprouts, apricots green leafy vegetables prunes, raspberries, Chinese greens breadfruit, custard apple watermelon, citrus found in most fruits most fruit and vegetables are low most are low, except for avocado

As far as foodborne illness goes, the most common risks due to fruit and vegetables come from three bacteria: ¥ Listeria monocytogenes ¥ E. coli ¥ Campylobacter.

Campylobacter is the bacteria behind most cases of bacterial gastroenteritis in developed nations such as Australia, the United States, Britain and others of western Europe. Listeria is found widely throughout nature. In particular we are concerned about its appearance in dirt attached to vegetables and in dairy products. Listeria is one of few micro-organisms not slowed down by refrigeration. The presence of a high number of Listeria bacteria indicates there is a problem with the food production and storage process. These potentially harmful bacteria are found on the surface of fruit and vegetables, so the main rules are:

¥ Before peeling or handling, wash all

fruit and vegetables well. ¥ Avoid cross-contamination from knives

and chopping boards. ¥ Choose safer vegetables and fruits —

those with strong skins (provided you don’t eat the skin). Cross-contamination can occur simply by using the same knife to prepare all the vegetables for your meal if you are removing skins (for example, onion or potato) as well as chopping (carrot, celery, lettuce). It is safest to wash the knife (or use another one) when moving between vegetables that are going to be cooked and those that will be eaten raw.

POTATOES When CHOICE magazine carried out a survey of potatoes sold in 4 kilogram or 5 kilogram bags, they found that, on average, 20

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per cent of potatoes in each and every bag showed signs of ‘greening’, in many cases potatoes had begun to sprout, had severe mechanical damage caused by machine harvesting and handling, or were infected by diseases such as ‘powdery scab’. Clods of soil were often hard to remove. All 120 bags purchased had been graded as number one or class one grade, so ignore the label and dig deeper if you want true quality. The most common question about potatoes is: When potatoes turn green, is the green bit poisonous? Well, that’s not quite the right interpretation. The green bit is not the poison. The green colour comes from chlorophyll — the same chemical that makes grass and leaves green. Plants produce chloro p hyll when exposed to light, which may come from the sun or from an artificial source like the light bulb in your kitchen or the supermarket lights. Any green section in potatoes is not

A ROCKY ROA D One of the fancy dishes at a function was a presentation fruit platter. The fruit had been sliced and placed in an attractive fashion, creating a focal point for the table setting that was also a delicious part of the meal. However, guests picked up Salmonella poisoning from the meal. Eventually this was traced back to the fruit platter, but not the fruit that was actually eaten … It turned out that Salmonella bacteria were on the outside, thick skin of the rockmelon. Experts believe the bacteria transferred from this skin to the flesh of the other fruit on the knife used. This incident highlights the ease with which cross-contamination occurs. It also puts pressure on us, as householders, to think about hard issues like how often we will wash our knives and chopping boards, our fruit and vegetables. To be safer, wash the outside of your melon — or other fruit and vegetables — before cutting.

poisonous. However, the conditions which lead to the production of chlorophyll also promote poisonous chemicals called glycoalkaloids. Solanin is the best-known of these s u b s t a n c e s. A small amount of greened potato should not cause any illness, but in l a rger quantities you could suffer fro m headaches, cramps, vomiting, diarrhoea or dizziness. Cooking will not remove the poison, so you should peel and chop away any small areas of green and the rest of the potato should be fine. Solanin concentrates in and close to the skin. But if there’s more than a small part of the potato that’s green, throw the whole thing away. Similarly, don’t eat the sprouts that form on potatoes once they start getting older. The sprouts actually concentrate these poisons, so cut them right out or, again, stick the whole spud in the bin or compost. You should also dig out the eyes, where dirt can hide. Scabs and powdery fungus on the surface of potatoes should simply be discarded. Cut deep under the skin blemishes and the rest of the potato should be OK. Potato tips: ¥ Washed potatoes look cleaner, but usu-

ally don’t last as long as unwashed ‘brushed’ones. ¥ Washed potatoes are more prone to

greening. ¥ Potatoes are often packed in pink plastic

bags. The colour helps slow down the greening process by blocking some light, but it also serves to conceal any green colour. ¥ Open the bag or peek through the air

holes to check for damaged or green spuds. ¥ Always check the price for loose pota-

toes versus bagged ones. You might find the loose ones cost a little more but you save money by weeding out the duds yourself.

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MUSHROOMS AND FUNGI While the mushrooms sold in grocers’ shops can be treated as safe, those gathered from your own mushrooming expeditions in the country must be treated with caution — unless you know how to tell the safe ones from the dangerous mushrooms and toadstools. Even local knowledge cannot always be trusted. But there are many, many variations and extreme care should be taken. According to media reports, villagers in Russia die every week from eating poisonous fungi. In Australia the ‘death cap’ mushroom, which is pale olive, white or green-yellow in colour, continues to catch people by surprise. Nausea, frequent vomiting and diarrhoea are the first signs of poisoning, showing up after a few hours. When fully absorbed in the blood stream the poison then attacks the kidneys and liver, destroying the body’s ability to cleanse itself. It is estimated that half the number of people who eat the death cap will die from it. Don’t eat field mushrooms if you don’t know the area and the local type well. The basic rules for identifying safe mushrooms are: ¥ Look for a white cap; and pink or light

brown ‘gills’underneath the cap. ¥ Avoid bright coloured flesh; or those

with dots and spots.

ALFALFA SPROUTS Alfalfa sprouts have become a popular salad vegetable. It is convenient to pull a bunch from a plastic container and thrown them on your salad as an attractive and nutritious topping. Do you bother to wash them first? They become somewhat waterlogged and soggy if you do. Yet alfalfa sprouts have their own little secret: Salmonella can find its way into parts of alfalfa seeds where we cannot kill them.

Several outbreaks of foodborne illness due to Salmonella in alfalfa sprouts have occurred in the United States during the mid-1990s. More than an estimated 20,000 people contracted Salmonella infections this way. Alfalfa seeds are stored for months or years in conditions which keep any Salmonella present stable. But they can multiply rapidly during the sprouting process. When we take sprouts home, we neither wash the sprouts nor cook them. Thus we are vulnerable. While food scientists are researching whether irradiation will deal with the problem, the very young, the elderly and those with reduced immunity should consider washing or cooking their alfalfa sprouts — or rejecting them altogether.

PACKAGED RAW SALADS Part of the move to a better quality of fast foods has been the emergence of ready-toeat raw salads. Typically a mixed salad is sealed in a plastic bag, ready to pour into a salad bowl when you get home. Barbecue a steak and dinner is served, quickly and easily. As you can see from the earlier part of this chapter, raw salad vegetables have their own special problems. Do these problems continue into the packages? On the risk side we have the added complication that the salad vegetables will have been handled, cut, mixed and packaged — increasing the opportunities for contamination. As you are probably aware, it is not an easy thing to thoroughly clean leafy vegetables like lettuce, or vegetables like mushrooms which have hard-to-access corners and folds. The moist surfaces of the vegetables will aid the multiplication and spread of micro-organisms. In supermarkets and greengrocer shops, packaged salads should be stored in refrigerated (chilled) conditions to slow down the multiplication of micro-organisms. Sometimes the salad vegetables have been treated with an anti-microbial solution containing chlorine or something which acts similarly. Rather than

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fill the bags with ordinary air, a modified atmosphere is created by some suppliers in the bag. Dressings can also be used to render the salads acidic and less attractive for bacterial growth, and this is often done in readymade commercial salads. These moves should keep the problems from becoming hazardous. The primary problems are: ¥ Listeria monocytogenes, which can grow

on raw vegetables even at ‘chilled’temperatures ¥ E. coli, from poor hygiene standards

among the handlers, or coming straight from the fields where the vegetables were grown. Just because it is a ‘healthy’ salad doesn’t mean it is safe. Raw, ready-to-eat salads have been responsible for regular outbreaks of food

poisoning around the world. From 1992 to 1997, for example, 43 outbreaks were recorded in Britain, affecting just over 1800 people. A variety of salad vegetables were found to have been contaminated: lettuce, tomato, coleslaw, onion, carrot, watercress, mushrooms and bean salad. Outbreaks have been reported in the United Sates (alfalfa sprouts grown from seeds contaminated with Salmonella), Sweden (bean sprouts), Australia (Campylobacter in cucumber) and Japan (E. coli in radish sprouts). Salads are a healthy choice for your diet, but should not be regarded as somehow purer or ‘immune’ from micro-organisms. So don’t be put off: the risk of illness is not great and the benefits are substantial. Fresher is better, too. The only rule is: ¥ Wash salad vegetables as best you can

before serving.

SUMMARY ¥ Wash fruit and vegetables, preferably under running water. ¥ Watch out particularly for dirt caught up in the leaves of lettuce, spinach, bok choy and

the like, or in deep ‘eyes’. ¥ Thick skins provide added protection against contamination. ¥ Don’t buy or eat potatoes if more than a small area is green. ¥ Don’t pick and eat mushrooms gathered from fields unless you can identify the safe

types. ¥ Prepared, chilled salads pose a potential health risk, as you are not likely to wash or

cook them yourself.

CHAPTER

7

THE BUTCHER’S SHOP

FROM BARBECUES TO FINE ROASTS, HUMBLE STEWS AND THE VERSATILE PLATE OF MINCE, WE USE MEAT IN SO MANY WAYS. For reasons of health and personal beliefs many are becoming vegetarian. Yet, even then, many will eat the occasional piece of meat in a meal.

forms. You just need to touch the meat to know bad things are going on inside. You may even be able to see the slime shining in the light. However, a surface sheen of green, blue and silver is the sign of harmless bacteria: you will see it on something like corned beef. Warning signs of ‘spoiled’ meat products are:

SPOILED MEAT

¥ a change in colour — the meat goes

Before turning to the food poisoning risks associated with meat, let us consider what is happening when meat ‘spoils’. Infecting micro-organisms release chemicals which disintegrate the connective tissues which hold the meat fibres together. Gas is produced and foul-smelling acids are formed, sometimes due to fermentation taking place. These acids also give the food a bad taste. Enzymes break down the natural barriers and membranes in the meat, making it possible for the bacteria to spread further and deeper within, spreading the infection. When bacteria start growing on the surface of the food, slime also

¥ patches of contamination may show

from pinks and reds to greys and browns other colours, such as yellow or green, black or white. The colours may even look luminescent. Look for patches of local colour that are different to the main colour of the meat. ¥ ‘off ’ smells — ‘putrid’ odours are due to

the decomposition of proteins and amino acids; ‘sour’odours result from the decomposition of sugars (as in sugarcured ham, for example). So, will spoiled meat cause food poisoning? The micro-organisms which lead to meat

65

M A D - COW SAU S AGE, ANYONE? spoiling are not the same as those which can lead to food poisoning. They are two separate issues (although spoiled meat is not an attractive proposition). But if the conditions exist for harmless ‘spoiling’ micro-organisms to grow, so can the dangerous ones. The majority of cases of bacterial food poisoning from meat products are due to Salmonella and Staphylococcus. Dangerous forms of E. coli can be present too. Another major cause of meat-borne illness is the family of Campylobacter (Campylobacter jejuni and Campylobacter coli). These bacteria are found widely among the animals we eat, especially chickens and turkeys, and enter the food chain at the abattoir. It only takes a small dose — as little as a few hundred organisms — to cause illness. Infants and young children are particularly at risk. Fortunately, as with so many other food problems, proper cooking will give a high degree of protection against the risk, as will some other treatments. For instance Campy lobacters are controlled by heat (cooking, pasteurisation), drying, acidity, and, in some countries, food irradiation. However, they can survive for several months in frozen meat.

MINCED MEATS AND SAUSAGES With chops and steaks, most contaminants will be on the surface, where cooking can generally make the food safe. But mince is another matter altogether. Minced meats are truly one of the great convenience foods. With some minced meat in the fridge you can always cook a number of tasty, hot dinners, from hamburgers and rissoles for the barbecue to spaghetti Bolognaise and tacos. However, many of the largest outbreaks of serious foodborne illness, especially

Mad cow disease is one of those things which grab world attention and shake us with fear and uncertainty. Mad cow disease — more properly known as bovine spongiform encephalopathy (BSE) — is a disease which attacks cattle. It is a brain disease caused by an infectious protein which destroys brain tissues and, eventually, causes the death of the animal. It is a disaster for the beef industry and hence all the noise and fury from Britain. But is it a worry for humans? Some researchers suggest there are similarities between BSE and a human illness called Creutzfeldt-Jakob Disease (CJD). Like BSE, CJD is a brain disease which leads to death after a period of dementia, loss of speech and reduced mobility. CJD does not appear to be highly contagious, but most cases are either genetic (a family predisposition) or acquired through a particular medical procedure (which ceased in Australia, for example, in 1985). Although there is no proof that humans can acquire CJD from eating BSE-infected beef or beef products (sausage skins, Bovril, anything containing gelatine or milk), neither is there proof that there is no link to human illness. In any event, the beef industry in Australia is free of BSE-infected cattle — it really is a problem associated with Britain. The British Government has taken measures to attempt to eliminate the risk. And British beef is now allowed back into European markets, having been banned at the time of the scare.

in the United States, have involved minced meat that has been inadequately cooked: the ‘pink’ or rare hamburger. But isn’t mince just steak, cut into little pieces? Where’s the problem? The surface area of a kilogram of mince is much greater than it was for a whole steak. Every little piece of

TIP

The starting point, when preparing meat in the kitchen, is to always assume that all meat comes to us contaminated. Cook it!

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mince is roughly a ball, with a tiny inside and, relatively speaking, a huge outside surface. Those ‘new’surfaces may have become contaminated with anything which was once only on the ‘outside’ of the original pieces of meat muscle. And all of these surfaces will have come in contact with cutting and grinding implements. So whenever you see minced meat you should remember: ¥ the greater the surface area of the food,

the greater the risk of contamination getting deep inside the food where only thorough cooking can reach it ¥ handling and processing can spread con-

taminants from the outside to the ‘inside’ of a product like mince. Sausages and rissoles are also minced products, so be careful. (The sausages we are looking at here are those you cook yourself, unlike the smallgood sausages discussed in previous chapters which are usually bought ready-to-eat.) While it is less risky to cook a steak ‘rare’, bloody and pink (because bacteria are mostly only on the surface, not deep inside, and are killed by the cooking process), you should ensure minced products like sausages and rissoles or hamburgers are well cooked. Look for these signs:

by the butcher: cutting, trimming, laying out, rolling and tying the roast. These are opportunities for contamination to get ‘inside’ the roll, moving from the original meat surface onto newly formed surfaces. Treat a rolled roast more like a sausage or hamburger. Cook it more thoroughly, so it is more brown than pink in colour, with clear juices running. Consider investing in a cooking thermometer for accurate information about your roasts. As mentioned above, chops and steak tend to be safer choices than mince, sausages and rolled roasts, as cooking on the outside protects against recent surface contamination from bacteria such as E. coli from faeces at the abattoir or Staphylococcus from the butcher who wipes his nose with his hand. At the present, not a lot is known about the extent of blood-borne viruses in meat. The blood-borne protozoan parasite Toxoplasma gondii (responsible for toxoplasmisosis) can sometimes be found in mutton and pork, possibly chicken but less often in beef. Thus pregnant women — or those planning for pregnancy (who have not previously been exposed to the organism and developed immunity) may wish to be extra careful and avoid eating rare-cooked meats. Ask for meat ‘medium’ or ‘well done’ instead.

¥ the meat should not be pink on the inside ¥ when stabbed, the juices flowing out of

the meat should be clear, not red or pink. You can apply the same rule to other foods in the butcher’s shop. For example, the common rolled roast, although appearing to be one big lump of meat, is in fact a slice around 1 to 2 centimetres thick which has been laid out on a bench and rolled into a cylindrical shape. The rolled roast has undergone quite a degree of handling and shaping

WHOLE POULTRY Salmonella food poisoning appears to be linked to the amount of Salmonella in animals in the fields. In Britain in 1979–80, it was found that up to 79 per cent of their frozen chickens were contaminated with Salmonella. A 1994 study of poultry in Northern Ireland, however, found quite a different picture — a contamination rate of only 7 per cent: ‘This may partially explain the lower rate of human

TIP

Mince has a larger surface area than the same weight of normal meat. Cook mince until ‘well done’; never ‘rare’!

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Salmonella infections in Northern Ireland [than Great Britain],’ said the researchers. In Australia it is safest to assume Sal monella is present and take appropriate precautions. Check cooked chicken before you serve it: open the spaces between wings/legs and the body and check they are not bloody. Before putting whole or partly carved chicken in the fridge, one trick, easily neglected, is to scoop out any stuffing/seasoning. Deep inside the chicken, stuffing can take several hours to chill to a safe temperature for storage, and bacteria can multiply to dangerous levels during this period. If you pull the stuffing out, it can be wrapped and stored separately, thereby cooling to a safe temperature much more quickly. Duck is another form of poultry which has a high risk of Salmonella contamination. Salmonella is known to infect the reproductive system of the birds and can therefore be present from hatching. Make sure any duck you eat has been thoroughly cooked. Similarly, ensure the centre of a large bird like the turkey has defrosted before you commence cooking it.

MARINATED MEATS Part of the trend towards pre-prepared meals is seen in the array of meal choices available now in the butcher’s shop: satay sticks, stir fries, seasoned steaks, souvlaki, cheese and herb rissoles, pepper steaks, and many more. There has been concern that the mixing of meat with sauces, marinades, cheese and spices, creates new opportunities for crosscontamination. A lot more handling goes into preparing and skewering kebabs than in slicing a rump. Seasonings can bring harmful microorganisms with them. Colourful marinades can also disguise old meat.

Cook marinated meats well. Do not treat them like an ordinary steak, where most problems will lie on the surface and are killed quickly in the pan or on the BBQ grill. Ensure the marinated meats and kebabs are cooked right into the centre.

PROTECTION STRATEGIES ¥ Raw or undercooked meats are a risk,

particularly chicken, duck and turkey or minced meats. ¥ Cook minced meat products until they

are brown or grey inside — not pink — and the juices flow clear, not bloody. ¥ Frying and stir-frying are effective if all

surfaces of the meat are seared and browned. ¥ Whole meat cuts, such as steaks and

chops, for example, can be left pink at the centre. ¥ Do not store raw and cooked meats

near each other. Watch out for crosscontamination from raw meat dropping blood or juices onto other foods placed lower in the refrigerator. Do not neglect to clean the fridge’s side walls, and try to keep raw meats from coming in contact with the walls. ¥ Cook foods to the degree necessarily to

kill the micro-organisms. Meat roasts and large birds such as chickens take time. If you have eaten a meat pie or lasagne that has been cooked in the microwave you have probably noticed that sometimes it is not cooked throughout, with scaldingly hot parts and cold, even frozen parts. This is dangerous territory. You must leave the microwaved meat to ‘stand’ for a number of minutes after

TIP

A whole roast is a safer choice than a rolled roast!

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‘cooking’ has finished (check with the instruction manual). During this time the heat passes from the outside to the inside. ¥ Keep pets and gardening implements

out of the kitchen. ¥ Do not leave cooked meats lying around

on the kitchen bench while you eat your

dinner. After carving or serving, put them in the fridge — otherwise you let the bacteria get off to a good start and you have created a little time-bomb for leftovers next day. If you think people will want seconds, cut off a chunk and put the rest into the fridge. Throw away what you don’t use, or feed it to your pets.

SUMMARY ¥ Assume all meat is contaminated. ¥ Do not serve meat raw. ¥ Steaks, chops and whole roasts can be cooked ‘rare’. But if you are pregnant it would

be wise to have all meat cooked more thoroughly than ‘rare’. ¥ Sausages, hamburgers, rissoles, rolled roasts and marinated or pre-prepared meat meals

should be cooked ‘well done’. ¥ Put leftovers into the fridge straight after serving. Do not wait until the end of the day.

It is safest to cook leftovers thoroughly once again before serving. ¥ Never use the same chopping boards, trays or utensils for cooked and raw meat: cross-

contamination can occur through the raw blood. ¥ Check that chicken and duck are cooked to the bone before serving.

CHAPTER

8

THE FISH SHOP

WE ARE ONLY JUST STARTING TO REALISE HOW IMPORTANT SEAFOOD IS IN THE HUMAN DIET. For a long time we — at least, those of us living in developed nations — have had a fixation on red meat as the central ingredient of what we eat. Dietitians now warn us against eating too much fat, particularly ‘saturated’ fat, which is found in animal products like meat and dairy foods. When the diet is high in saturated fat, the body may make too much cholesterol. The fat in seafood is mainly unsaturated. In addition, seafood is: ¥ an excellent source of protein ¥ low in fat and kilojoules ¥ contains many minerals and vitamins,

including iron, iodine, niacin, vitamins B6 and B12. Some fish are also a source of vitamin E and vitamin D. Prawns provide some calcium, iron and zinc. Oysters and mussels are very high in iron and zinc.

In recent years scientists have learned even more about seafood and the positive health benefits it can bring. Some seafood, particularly ‘oily’ fish such as mackerel and salmon, contains a type of oil or fat which is good for our heart health. Called ‘Omega 3 fatty acids’, they are polyunsaturated fats which are now known to be an essential part of the brain and nerve cells. Omega 3 fatty acids help fish survive living in very cold seas, preventing their bodies from simply freezing. Humans, on the other hand, find Omega 3 acids helpful in preventing blood clotting arising from injury or illness, and in handling the responses of the body’s immune system. They produce prostaglandins (which are like hormones) that become useful in the arteries and in the way the platelets in blood cells stick to one another. Put simply, they are very good for our heart and blood vessels. There is also some suggestion they may help protect our bodies from development of some cancers or arthritis. Seafoods rich in Omega 3 include: swordfish, herring, mackerel, ocean trout, salmon, and sardines.

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Seafood is also low in fat, yet shellfish are high in cholesterol. So, should we eat a lot of it, or avoid it? There are different kinds of cholesterol, both helpful and potentially harmful. Cholesterol is a waxy substance which can block arteries leading to angina, heart attack and cardiovascular disease. However, our bodies need a certain amount of cholesterol in order to function properly. It is part of the structure of nerves and brain cells, helps make bile salts for the digestion of fat, and contributes to the creation of some hormones and vitamin D. Our bodies produce cholesterol naturally — around 1 gram each day comes out of the liver. But some people’s livers produce too much cholesterol, and some people simply consume an unhealthy amount of cholesterol in their diet. If you are making or eating too much cholesterol you are on the slippery slope to heart disease. The kind of fats that cause the body to make too much cholesterol can be found in: ¥ meat — particularly red meat and the

The ‘fat’ problem with many of these types of seafood arises when the chef adds things to them: deep-fried tempura batter in Japanese cuisine; battered fish from the takeaway; rich, creamy sauces piled onto oysters. There is also a fat problem with the foods which often accompany fish: French fries or chips, potato scallops, and the like.

FISHY RISKS Two of the greatest food risks are with foods which come from animals, and foods which are never cooked, either by the manufacturer, the caterer or chef, or by you at home. Few foods possess both of these risk factors, but you will find four examples in your fish shop or at the fish counter of your supermarket: ¥ sushi or sashimi ¥ pickled fish ¥ smoked fish ¥ oysters.

fat on the meat ¥ eggs (the yolk) ¥ many dairy foods, including milk, cheese

and butter ¥ fast foods, fried foods, hydrogenated

vegetable oils used in margarine and many processed foods. Seafood contains ‘pre-formed’ cholesterol, but almost no saturated fat, so dietitians believe they do not lead to harm. Prawns (shrimp) contain the most cholesterol, but less than 30 per cent of it is absorbed by the body. Other seafood which is now believed to be less of a threat to the heart includes squid (calamari).

These offer micro-organisms an easy ride. Which ones are the threat? While seafood can be contaminated with bacteria, it is perhaps better known for the viruses that cause foodborne illness. In particular hepatitis A and Norwalk. One of the main bacteria we look for is Listeria monocytogenes. Hepatitis A typically has a faecal source and is transmitted, for example, by people who don’t wash their hands after going to the toilet. Kissing will also do the trick. Travellers to developing nations often bring the virus home from overseas. Hepatitis means an inflammation of the liver, which swells and becomes tender to touch. People who catch hepatitis A often end up in hospital during the

TIP

You cannot always protect yourself against viruses like hepatitis A and Norwalk. When travelling, or otherwise when you want to take extra care, avoid prawns, oysters, mussels and the like. Go for cooked seafood, not raw seafood!

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first few days, as symptoms — fever, vomiting — can be very serious. Generally the illness runs its course over a month, although ongoing debilitation is not uncommon. The incubation period is quite long, being anywhere from 15 to 50 days after the person picks up the virus. There is a ‘window’ of around one week before the first symptoms appear, where the carrier can unwittingly pass the virus to others. This makes it a real problem in the food preparation and hospitality industries. It is a fairly similar story with the Norwalk virus, however the symptoms start one to two days after eating the infected food. Fortunately the symptoms — mild fever, vomiting and diarrhoea — are not generally as severe as with hepatitis A, but it may be transmitted through the air. Certain seafood (along with salads) carry the viral risk. Sewage-polluted water contaminates the creatures which live in it, and sometimes sewage-polluted water is used to rinse seafood once caught or retrieved from nets and pots. The seafoods to watch particularly are: ¥ oysters ¥ molluscs, such as mussels and clams ¥ shellfish, such as prawns (shrimp),

where you are eating the whole animal. In general, prawns are a safer choice than oysters or molluscs, if the digestive tract has been removed.

A TALE OF TOXINS Bacteria and viruses are not the full story. There are many other pathogens floating around the sea which have a particular affinity for seafood. Toxins produced by these organisms are a real concern facing health authorities. Examples include: ¥ scombroid — in tuna, sardines, bonito

and mackerel

M OT H E R S ’ DAY MAL A DY F o u rteen people who celebrated Mothers’ Day 1997 with a meal at a Chinese re s t a urant in Sydney had a nightmarish souvenir of the day when, some weeks later, they came down with hepatitis A. Another three people, who had eaten there a week later, also became infected. Ten of these people were women, and seven men, ranging in age fro m seven to 48 years. Some were hospitalised for tre a t m e n t . When public health authorities were alerted to the outbreak and the link to the one restaurant, it voluntarily closed its doors Initially there was some public speculation that the source of the outbreak could have been due to a breach of hygiene standard s within the restaurant. However, investigations revealed that prawns were to blame, p e rhaps due to contamination during importation or distribution. The staff and re s t a urant were exonerated and the business was c l e a red to re - o p e n . These were not local prawns — they were f rozen prawns imported from Burma. Upon identification, the importer voluntarily recalled the product from wholesalers in Australia. Even a good restaurant with high stand a rds can pass a contaminated food on to its customers. Prawns are a particular risk because they often undergo only minimal cooking, sometimes in river water.

¥ ciguatera — in snapper, sea bass,

morays and some tropical fish like the barracuda ¥ dinoflagellates — in shellfish.

Some toxins produce nasty symptoms very quickly, even from the first bite. Tingling of the tongue and throat, numbness, nausea, headache, dizziness, visual disturbances, even paralysis can strike the unfortunate victim. Sometimes the toxins can be fatal.

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Compounds naturally in the seafood (histamines and neurotoxins) can also be a threat. Histamines produced by bacteria on fish can cause headaches and other allergy-type symptoms — a common problem related to poor storage. Algae can produce toxins which become concentrated in the food chain as smaller organisms are consumed by larger ones, and eventually by us. The toxins cannot really be detected by taste, so we rely on knowledge in the fishing industry about particular locations and events (such as hurricanes) which are associated with increased danger. On the whole these toxins do not affect a lot of people in developed nations. However, the numbers increase in certain locations which are favoured by tourists and lovers of both the sea and seafood: California, Hawaii, the Virgin Islands, for example. The vast amount of seafood eaten in these places could also have something to do with explaining the larger numbers of reported cases. What can you do about toxins in seafood? With the common viruses and bacteria, cooking offers improved protection, but toxins are a different kettle of fish. Cooking offers little protection, so we must rely on the industry not to harvest seafood from known problem areas.

MOLLUSCS Oysters and molluscs — mussels, cockles, whelks and winkles — are at the risky end of the seafood spectrum because they are ‘filter feeders’, accumulating micro-organisms in their organs and flesh as they draw in water. They are a little like your vacuum cleaner, sucking in a lot of dirt with the air and trapping the dirt inside with filters. They are also easily contaminated during handling and processing, in the factory, fish shop or at home. A British test of pathogens in molluscs rated 13 per cent of mollusc samples ‘unsatisfactory’, although only 1 per cent were regarded as a potential risk to public health.

Overall, it is not a high risk in developed nations. However, there have been many small outbreaks in a number of countries: ¥ Britain, 1986–87: more than 800 people

caught a viral infection (small round structured viruses) after eating cockles. ¥ New Zealand, 1992: A pregnant

woman became ill, and suffered the premature birth and death of the twins she was carrying, after eating cooked mussels contaminated with Listeria monocy togenes. ¥ Spain, 1995: one person picked up

Vibrio cholerae from mussels sold by a supermarket.

¥ Britain, 1997: nine people became ill

from Salmonella enteritidis, after eating cockles which had been gathered by members of the public (not professional fishermen), who cooked them and sold them through a local fish and chip shop.

Over the decade from 1986 to 1996 more than 1100 people in England and Wales were affected by food poisoning from ready-to-eat, de-shelled molluscs (for example, those in restaurant meals or bottled). There were 19 distinct outbreaks in all. The same British study also sheds light on the issue of which retail outlets are the most risky. Molluscs purchased from supermarkets and fish shops were likely to be safer than those purchased from seafront stalls and mobile vendors, with one-quarter of the number of ‘unsatisfactory’ samples when compared with the stalls and mobile vendors. This is probably what you would have expected anyway, given the lack of refrigeration and facilities to prevent cross-contamination. And sometimes ‘local’ seafood has been harvested from contaminated waters. The message is clear: molluscs are a type of seafood that inherently presents greater risks than many other types. If, however, you want to eat mussels, cockles or the like, it is

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AT WHAT CO S T ? In early 1997 the New South Wales Health D e p a rtment issued repeated warnings urg i n g people to avoid eating oysters from Wa l l i s Lake while an outbreak of hepatitis A worsened across the state. Well over one hundre d cases of hepatitis A had a ‘significant’ link with oysters coming from that area, with victims spread across New South Wales and Queensland. During the investigation, the local industry a g reed to discontinue harvesting oysters fro m Wallis Lake. A voluntary recall of oysters fro m the market followed. Although hepatitis A can be transmitted by poor personal hygiene, investigators ruled out blaming food handlers as oysters implicated in the outbreak had been sourced from diff e rent parts of the lake. Diff e rent companies and d i ff e rent handlers were involved. Several agencies were brought together to work on the crisis. As well as the Health D e p a rtment there were the Department of Land and Water Conservation, the E n v i ronment Protection Authority, the Gre a t Lakes Shire Council, New South Wa l e s Fisheries and the New South Wales Shellfish Quality Assurance Program. An ‘enviro n m e ntal audit’ of Wallis Lake was undertaken to s e a rch for the cause of the contamination. This included testing of sediment and oysters f rom the lake. An outbreak like this can cost the community a huge amount of money and spend significant re s o u rces. It can also be devastating to the oyster industry. Of course consumers, too, had suff e re d g re a t l y. In March 1999 the Federal Court of Australia awarded $30,000 damages to a man who had been poisoned by the oysters. The p residing judge found that Wallis Lake was poorly managed, breaching health guidelines and resulting in ‘widespread human faecal pollution of the waters of the lake’ discharg e d f rom septic tanks. There were 185 similar cases, with total claims estimated at about $7.5 million. At the time of writing, negotiations were underway to attempt to settle these claims.

wise to buy them from a supermarket or dedicated fish shop, rather than from a mobile vendor in the more romantic setting of the pier or beach front.

PROCESSED FISH Fish fillets and whole fish — other than certain tropical varieties mentioned above — are generally the safer options from the seafood menu. They also benefit from cooking, whether in the pan, on a barbecue, or in the oven. Boiling lobsters, yabbies, crabs and the like helps rid these foods of many contaminants. It is what happens afterwards — storage and meal preparation — that is the greatest concern. However, once seafood enters the processing factory there is room for contamination. Several studies in Britain have found consistent, low levels of Listeria in raw or processed seafood, including: ¥ fish and shellfish pate ¥ smoked fish ¥ raw fish ¥ fish fingers ¥ fish cakes.

Seafood should not be stored in the fridge for a long time. It is prey to pathogens such as Listeria monocytogenes, which can multiply to hazardous levels even in the refrigerator. The problem really comes down to seafoods which are served raw or after minimal cooking. Those which are least likely to be contaminated with L i st er i a are frozen seafood, and pickled fish and seafood (because it has a low pH). Seafood is truly one of the most tasty, enjoyable and healthy choices for us to eat. In a country like Australia the risk of foodborne illness from seafood is low. However, we have constant reminders — such as the Wallis Lake and Sydney Chinese restaurant incidents — that dangers such as hepatitis A are around us. If you want to take extra care, it makes sense to avoid oysters, mussels, prawns and seafood pate; and don’t undercook your seafood.

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SUMMARY ¥ Seafood undergoes a lot of handling during processing, transport, and selling. Less of a

problem is seafood which is packaged, such as fish fingers (although they are highly processed), which goes into your freezer and is then cooked straight from its frozen state. ¥ Cooking remains an enormously helpful way of protecting yourself against many of the

problems associated with seafood. ¥ Riskier types of seafood are oysters, prawns (shrimp) and molluscs (mussels, cockles).

It’s safest to eat them cooked; if you want them raw, check the shells are unopened when you buy them. ¥ Beware of seafood caught in dirty waters. Before you eat the local catch — particularly

if you’re on holiday in an area you don’t know well — look to see if there are stormwater drains and sewage emptying onto the beach or bay. ¥ Fish pate is easily contaminated. ¥ Eat raw seafood — such as sushi, sashimi and oysters — only in a city with high stan-

dards of food hygiene. ¥ Select fresh fish where possible.

CHAPTER

9

A SWEET TOOTH

FOR THE PERSON WITH THE SWEET TOOTH, THE PROBLEM FOODS ARE FEW. MOST LOLLIES OR SWEETS ARE SAFE FOODS GIVEN THEIR HIGH SUGAR AND CORRESPONDING LOW MOISTURE LEVELS. However, there have been some outbreaks of illness relating to certain sweets. There is also the chance of a foreign object getting into the mix. In 1998 a British confectionary manufacturer was acquitted of negligence because the head and shoulders of a mouse found in its chocolate bar, had come from a supplier of hazelnuts in Turkey, not because of any lack of diligence by the chocolate manufacturer itself. (That judicial finding might not be of great comfort, however, to most of us.) The riskier sweet foods are fairly obvious once you have some insight into their ingredients and processing. The three categories we will deal with here are cakes, icecreams, and chocolate (candy).

CAKES Apart from their fattening potential, cakes made without eggs are not very risky foods. When cake-makers have got into trouble it has usually been over three ingredients: ¥ eggs ¥ cream ¥ custard.

They seem obvious candidates. But there are surprises in store.

¥

The problem with eggs

In 1995, 36 children became ill (with diarrhoea and, in some instances, vomiting) after eating marshmallow cake in the Bath/Wansdyke region of Britain. The average age of the sick children was only five years. The culprit was Salmonella enteritidis (a type, it is worth noting, that has not become

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a real problem in Australia). After tests of bakery staff showed they were all healthy, and tests of the cooking benches and the premises came up negative, it was found that marshmallow cones contained the bacteria. How could the humble marshmallow make someone sick? Marshmallow is often made from sugar, water, gelatine and flavouring, but in this instance it was made using egg white as a whipping agent — which happened to be in breach of British health guidelines. Eggs are at risk from Salmonella and recipes which use raw eggs without subsequent cooking simply pass on any danger. The cake in question was a common one, where a layer of marshmallow was held squeezed between wafers or a cone. The chef had combined a proprietary tinned marshmallow mix with raw egg white and allowed the cake to set cold — there was no cooking. Interestingly, the marshmallows were not the kind prepared and packaged by a major confectionary company, but a local bakery or cake shop. It was simply a case of a single shop failing to follow safe procedures. Pasteurised, dried eggs are usually used by chefs and caterers to deal with the problem of Salmonella. Other foods at risk from uncooked eggs include: ¥ foods containing mayonnaise, such as

salad dressings ¥ mousse ¥ some dipping sauces which use raw egg ¥ body-building drinks ¥ egg nog ¥ custard tarts ¥ meringues made from eggs.

Also in Britain, there was a similar outbreak of Salmonella enteritidis from a Meals on Wheels service for the elderly. Out of 105 elderly people who received the particular meal in question, 61 developed diarrhoea, 27 were admitted to hospital and, sadly, three

died. Even the chef became ill, having eaten his or her own dessert. The average age of those affected was 75 years. Again, the kitchen and staff were tested and cleared of carrying the bacteria. However, detective work closed in on the strawberry mousse as the common food eaten by those who became ill. The mousse was prepared with 60 eggs straight out of their shells; the mousse did not undergo cooking; and was left out at room temperature for two or three hours before distribution by the drivers. Raw eggs can turn up in surprising places. In 1995 five men aged 17 to 25 years who attended the same gym reported symptoms of diarrhoea, vomiting fever and other flu-like symptoms. When tested, the victims were found to have been infected with Salmonella enteritidis. The gym was the only connection between the five. Upon investigation at the gym, it turned out that all five had consumed the same body-building drink, mixed freshly for each customer. The drink was a proteinrich concoction of dried semi-skimmed milk powder blended with raw egg. Although the drink had been offered on sale for eight years, it was unknown whether others had become ill from this risky recipe, and the investigation did not continue. Yet the incident remains cautionary for body builders and others eating ‘healthy’ uncooked drinks containing egg. Raw eggs and Salmonella — a cozy partnership to watch out for! Fo rt u n ately in Australia there is little impact from this type of Salmonella, although it is always a threat for the future if standards slip.

¥

Custard and cream

Custard and cream cakes, on the other hand, are readily contaminated with Staphylococcus aureus. The consumer falls victim to vomiting, diarrhoea, stomach cramps, fever and weakness some two to three hours after eating the infected cake. Staphylococcus aureus loves custard and cream, and commonly makes the connection

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thanks to unhygienic practices by those working in cake shops. The bacteria is carried in the nose and facial hair, as well as on the hands, of people with the infection. A scratch of the beard, a careless wipe of the nose and the bacteria is onto the cake or into the custard mix. Bacillus cereus is another problem bacteria for these cakes. Jams, fruit cakes, fruit puddings, caramel and chocolate sauces, like confectionary, have had much of their moisture removed, making it hard for bacteria to grow to large numbers. For this reason you don’t have to refrigerate these treats (unless the label says otherwise, as some do). However, before you eat anything which has been stored in the pantry or at room temperature, check for moulds growing on the surface. In general, throw away any soft foods which are growing mould.

cern for the person travelling through developing nations (where food hygiene may be poor) or in parts of Europe where unpasteurised egg or milk might be used in the recipe. Outbreaks of illness still occur around the world. Home-made icecream is a luxurious treat with a depth of flavour and smooth texture which is often missing from the commercial product. And although food poisoning from commercially made icecream has all but disappeared in developed nations, home-made icecream remains a concern, particularly at functions. The basic problem is that home-made icecream may use unpasteurised raw eggs. Some recipes sidestep this problem by using cooked egg custard and cream, instead of raw eggs. There are many bacteria which have a close association with icecream:

ICECREAM AND OTHER FROZEN TREATS

¥ Listeria monocytogenes

Do you remember becoming sick after eating an icecream? The chances are good that you have nothing but positive memories of icecream. Yet, before the early 1950s, large outbreaks of food poisoning associated with icecream were common, even in countries like Britain. Pasteurisation became an effective and widely used technique to give us a safer product. The warning bell should sound, when you come to think about it, because icecream is a dairy product — protein-rich, moist and ready to feed hungry bacteria. Icecream is sensitive to temperature and might soften and re-freeze during transport or in the shop. Soft-serve and cone icecreams can also pick up pathogens from those who prepare, handle and serve them. They are a much-handled food, often served in conditions which are far from ideal: hot summer days in the outdoors, in parks, on beaches, sold from vans or by roving vendors, by staff who are also making sandwiches or preparing other foods at the same time. These days, hard icecream is more of a con-

¥ Bacillus cereus

¥ E. coli ¥ Staphylococcus aureus ¥ Salmonella.

JUST MADE FOR PA RT I E S In the United States, in the decade fro m 1966 to 1976, there were 22 outbreaks of S a l m o n e l l a associated with home-made icec ream. Several of the outbreaks were due to the same product from the one supplier — a n o n - d a i ry icecream called ‘chiffonade’ — used at a number of parties and banquets f rom New York city to the states of Connecticut and Maine during 1967. Contamination by the food handlers was ruled out because no fewer than 12 diff e re n t private catering companies were involved. Clearly it was the product, not the staff . Of the nearly 3500 guests attending these celebrations, half became ill with salmonella g a s t roenteritis. The S a l m o n e l l a was traced back to unpasteurised eggs used in the mix.

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Some people might think that a packaged icecream is always the safest choice. That is true in one respect. The package helps protect you against pathogens coming from the people who serve you in the shop. The sales assistant who serves food with bare hands, while coughing and pushing back a wayward hairstyle, is nothing to fear here. But don’t assume the package solves all problems. Icecream must be kept at freezing temperature at all times. If it has defrosted during transport or in a poorly monitored freezer in the shop, it might have thawed and, possibly, become re-frozen at a later time. A vendor moving through a crowd at a sports event will carry nothing more than a little ice to keep the icecreams at a low temperature. In itself, thawing is not a health problem — the icecream might taste or smell ‘off ’, but you won’t suffer food poisoning unless harmful micro-organisms were already inside the sealed packaging, or the packaging has been torn or opened. Watch for the following signs that partial thawing has already taken place: ¥ Is the icecream, in its container or

poisoning’ noted the study’s authors at the UK Public Health Laboratory Service. No one is sure how Salmonella made it into the icecream, past all the protective techniques of a commercial manufacturer. Some scientists believe that high fat or high sugar levels in certain foods help shield Salmonella from the devastating effects of the stomach’s natural gastric barriers, thereby permitting the bacteria to gain access to the small intestine where they flourish and cause illness. Many of the samples in that study showed that bacteria were growing in large numbers. This was particularly the case with unbranded hard and soft-serve icecreams. Although the bacteria were not harmful types, the fact there was such growth in numbers suggests there had been a breakdown in standards at some point between manufacture of the frozen treat and its retail sale. If there had been a failure of hygiene at the factory, later mistakes would have allowed a harmful bacterium to thrive and increase in numbers to the point where a food poisoning risk came about.

wrap, soft when you pick it up? ¥ Has the icecream, if in a paper wrap-

ping, lost its shape? ¥ Are there signs that melted icecream

has run down the stick or stained the outside packaging? Related products are also open to contamination. Gelati, for example, was the food behind a case of food poisoning from South Australia in 1998. Salmonella oranienberg was to blame for this one. A British study in 1993 of several types of frozen snacks (hard and soft-serve icecream, frozen yoghurt, sorbet and ice ‘slush’) found little to cause consumers to worry. However, Salmonella was found in one out of 1000 hard icecream samples. This ‘suggests that commercially produced icecream may still occasionally be a potential cause of food

INGREDIENTS FROM THE B ACK OF THE T R UC K P e rhaps the largest outbreak of foodborn e illness traceable to icecream occurred in 1994 in the United States, with more than 200,000 people affected nationally. G o v e rnment officials, after a thoro u g h investigation, concluded that the bacteria Salmonella enteritidis made its way into the i c e c ream mix from contaminated residue left in a truck trailer which had later carted the i n g re d i e n t s . The same truck which transported pasteurised icecream mix for manufacture at another location had previously carried raw eggs. Presumably the eggs had been contaminated with the bacteria; and the icecre a m became contaminated after it had been pasteurised.

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In Australia, the Consumers’ Association reported on a test of soft-serve icecream in January 1996. Some problems were detected, including the presence in some samples of Listeria monocytogenes or staphylococcal bacteria, but the main problem was a high ‘standard plate count’ (overall number of bacteria). This, like the 1993 British findings mentioned above, is an indication of poor hygiene practices, not necessarily a sign that someone eating the icecream would become ill. So, the good news is that the survey found little evidence of a serious health safety concern, but plenty of evidence that hygiene standards could be raised. A similar survey, carried out in 1994 in the European cities of Barcelona, Rome and London, by the British Consumers’ Association found much the same situation. They tested the local favourite styles, including gelati in Rome, mostly soft-serve icecream in Barcelona, and hard icecream from London. Nearly half the samples failed microbiological guidelines contained in the British code of hygienic practice. As worrying as the poor results are, yet again there was little sign of icecream ready to deliver food poisoning: ‘Dirty but not deadly’was the diagnosis. Owners of shops and mobile vans selling soft-serve icecream must clean out their machines every day, never leaving the icecream in the machine overnight. The consumer’s health depends on the owner’s diligence day after day. If the premises, van or icecream dispenser are dirty or poorly presented, it may be wise to avoid the soft-serve — particularly anyone who is pregnant, elderly, with reduced immunity, or very young.

ICECREAMS: WHEN IN DOUBT Best choices

Caution

Brand-name hard, packaged icecream

Soft-serve

Brand-name hard ‘scooped’ icecream

Home made Unbranded

It is not a perfect process. When it comes to icecream and other frozen treats we really rely on the manufacturers getting it right, because there is a real risk that the transport or retailer might get it wrong. What we, as consumers, should not leave out of the equation, is our own hygiene. Icecreams are often eaten while we are enjoying the great outdoors — at a sporting event or agricultural show, at the beach or the movies. We walk in the park, sit on the grass, touch the ground, then hold an icecream. Kids, particularly, will lick the dribbling icecream off their unwashed fingers. You can’t blame the icecream. Yet, the real message for those of us living in developed nations, is that icecream is a potentially very unsafe product which, through careful regulation and attention to hygiene by manufacturers, is now a very safe product.

CHOCOLATE Chocolate is a highly emotive food; we love it but, at times, we feel guilty about its pleasures and its saturated fat levels. Chocolate has also had the occasional run-in with Salmonella. In the 1970s there were outbreaks of chocolate-borne Salmonella in the United States and Canada; in 1982 contaminated chocolate coming into Britain from Italy was responsible for at least 272 people becoming sick from Salmonella infection. An interesting aspect of the relationship between chocolate and this bacteria is that a single chocolate bar may be enough to make a person ill. As with rich icecream, it is believed that the fat in chocolate helps protect the bacteria from stomach acid. Once successfully past the stomach, Salmonella multiplies in the intestine and the toxin it produces is absorbed. Another Salmonella food poisoning outbreak in Norway also involved chocolate. One very hot summer day staff at a chocolate

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factory opened roof vents to make working conditions in the manufacturing area more tolerable. Some birds flew in and happened to do droppings over the vats of hot chocolate. Although the chocolate was at about 60°C (140°F) at this stage, the Salmonella survived and later infected a number of children who ate the chocolate bars. It is a sad day indeed when you can’t trust chocolate to make you feel good. Fortunately it’s not a common problem, so feel free to enjoy it!

¥

Exploding chocolates

Have you ever had a chocolate which had broken at the seams, spilling its filling into the box? It is not always the fault of rough handling. In fact there have been instances of

Easter eggs spontaneously exploding. What is happing in the chocolate world? There are a couple of sugar-loving culprits whose work is damaging to chocolate: Chrysoporium is a mould which thrives on the sugar in chocolate and which breathes out carbon dioxide. Zygosaccharomyces rouixii is a yeast which also produces carbon dioxide during fermentation. As the gas builds up inside the well-sealed chocolate, the pressure mounts, sometimes to ‘splatter-point’. You might never look at chocolates the same way again! Fortunately for chocolate lovers, these organisms are harmless to eat. The chocolates they like best are the ones containing jellies, for example Turkish Delight. The ones they don’t like are the liqueur chocolates, thanks to the tiny amount of alcohol inside.

SUMMARY ¥ Lollies (sweets) and jams are very safe foods. ¥ Cream or custard-filled cakes are riskier choices from the cake shop. ¥ Icecream poses little risk in developed nations; be more careful in developing nations. ¥ Soft-serve icecream is more of a risk than ‘hard’ or frozen icecream. ¥ Don’t eat packaged icecreams which have lost their shape or started to leak. They may

have become partly de-frosted at some point before being re-frozen. ¥ Check fruit cakes, puddings and sauces for moulds growing on the surface.

CHAPTER

10

THE SUPERMARKET

WHERE WOULD WE BE, IN OUR WESTERN SOCIETIES, WITHOUT THE SUPERMARKET? Some of us might still hunt down the exquisite small shop with its unique food products and personalised service, but the pressures of work and time have led most of us to the automatic-opening doors of Woolworths, Coles, Bi-Lo, Safeway, Jewel, Franklins and a host of others. Large supermarkets represent enormous

economies of scale. They might only make a few cents per item, but the sheer volume can render them enormously profitable overall. Coolrooms, state-of-the-art freezer cabinets and sophisticated monitoring systems help keep their food safe. In Australia the supermarket industry is held in relatively few hands. Although there are large numbers of different supermarkets, the majority of trade names are owned or controlled by just four chains.

AU S T RAL I A’S SUPERMARKET CHAINS The Coles Myer group

Coles, Bi-Lo, Big and Mega Frrresh, Pick n’ Pay

The Woolworths group

Woolworths, Safeway, Metro, Purity, Flemings, Food For Less, Cannons, Family Fare, Family World

The Franklins group

Franklins, Franklins No Frills, No Frills, Franklins Fresh

The Davids group

Jewel, Clancy’s, Payless, Foodtown, 7-Eleven, Tuckerbag, Quix Food Stores, Spar, Festival IGA, Cut Price Supermarkets, Foodstore, Four Square

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The Woolworths and Coles Myer chains alone account for 60 per cent of all supermarket sales! With that sort of concentration we can expect that a high standard of food safety systems will be in place. Your supermarket might include ‘shops’or areas which were once the domain of specialist stores covered already in this book: the greengrocer, the delicatessen, the fish shop. In this chapter we shall look at what is left over: canned foods and frozen foods, eggs and vegetarian ‘meats’.

CANNED FOODS When we put food in a can we solve many safety problems. It is protected from the outside world with its dirt and contaminants. The contents will not be handled by an infected worker; no amount of coughing and sneezing will harm it until it is opened and the seal is broken. But there is a particularly nasty bacterium which can thrive inside the can: Clostridium botulinum. You may have heard of ‘botulism’ — the name of the illness it causes. This is one of the most famous food-poisoning organisms throughout history, known as long as 1000 years ago. Commonly it comes into our food supply from the soil, where it is found naturally. The bacteria form spores which then produce toxins. Amazingly, neither the bacteria nor the spores are harmful to humans. But the toxin they produce is one of the deadliest we can encounter in food. Like so many other micro-organisms, there is a connection between the conditions in which it thrives and particular types of foods or processing. Clostridium botulinum spores are very resistant to heat, and survive well in places where there is no air (‘anaero-

bic’ conditions). As a result of these attributes, we must be particularly aware of it turning up in canned or bottled foods and sausages or salamis. We attack this bacteria by adding nitrate to sausages, salamis and other meats. Foodprocessing companies heat the food inside the can (a form of pasteurisation). In the home, you can best protect yourself by boiling, or almost boiling, the food for about 20 minutes (soups are a good example of this). Fortunately the protections are working. Since 1980 there has been only one outbreak of botulism in Australia. The second problem with cans is that the shell is vulnerable. Once the can’s structural integrity has been breached there is a pathway for contamination to enter. On the shelves, check cans for warning signs: ¥ bulging or distortion in shape — could

indicate the presence of gas-producing bacteria or other chemicals at work ¥ rust on the can — could signal there has

been an opening to the air outside the can ¥ damage and dents to the can — could

indicate damage to the inside lining of the can and possible puncture ¥ signs of any leakage. Check the seam

down the side of the can, and any ringpull or other easy-opening system. ¥ Don’t buy the can if it does not have its

original label.

FROZEN FOODS As already discussed, refrigerators and freezers don’t usually kill bacteria and dangerous

TIP

Vacuum-packed foods should be held firmly in place inside their plastic wrap. If the food moves around it may mean the packet has sprung a leak, through which contamination could occur.

THE DAY THE PEANUT BUTTER DISAPPEARED Sandwich spreads, from jam and honey to yeast-based ones like Marmite and Vegemite, generally have a strong reputation as safe foods. As a result of their safety, convenience and taste, they are found in homes and food shops across the nation, on our toast and inside our sandwiches. That’s possibly why it came as such a great shock when, in Australia in 1996, Salmonella was found in Australian peanut butter. Kraft, one of Australia’s largest food processing companies, and General Foods (a subsidiary), ordered a recall of all their peanut butter products, including those that did not appear to be contaminated. This affected around ten brands including Daffodil, Kraft, ETA, PDF and generic brands, as well as muesli bars and satay sauces which incorporated peanuts from the contaminated source. The Salmonella was apparently introduced by mice or rat droppings in peanuts held at the warehouse of the supplier, the Peanut Company of Australia. This is where the peanuts were roasted before being sent to those who made the actual peanut butter. It is believed the contamination occurred after the peanuts had been roasted, while they were in storage and awaiting transport. Most brands of peanut butter were pulled

micro-organisms: they slow them down and prevent them from multiplying rapidly. If frozen or chilled foods have not been kept at a safe temperature there is a risk that any microorganisms already present inside the packs will grow to potentially harmful numbers. Proper processing techniques should ensure, however, that there are few or no dangerous organisms inside the packs. But the plastic bags and other packaging of frozen foods are typically much more vulnerable to damage than, say, a can. Vacuum-packed foods should be held firmly in place inside their plastic wrap. If the food moves around it may mean the packet has sprung a leak, through which contamination could enter.

from the supermarket shelves. A market worth $60 million per year was ravaged as consumers kept clear. More than 2000 people were reported to be seeking compensation, as part of a class action, for illness they claimed was due to eating contaminated peanut butter. It was set to be the first class action in Australia over food contamination. Over a five-day period, a reported 100,000 consumers telephoned Kraft for information about the recall. It became one of the big news stories of the time. One of the real concerns for consumers was why wasn’t the Salmonella detected at the factory? Here we are talking about one of the largest and most sophisticated food processing corporations in Australia. Kraft is an impressive multi-national company with great experience and resources. If Kraft missed the problem, people asked, what hope do smaller food processors have? Further questions were raised about the value of complying with ‘international standards’ and the use of ‘approved, registered laboratories’ for quality control if a problem like Salmonella could still slip through. Six months after the recall began, the Kraft and General Foods brands of peanut butter returned to the supermarket shelves, filling a huge hole. It will take longer, however, for the wound to heal.

¥

Freezers

There are two types of freezer in the supermarket: the upright cabinet and the chest freezer. Sometimes there are sliding glass or Perspex doors on the chest freezer. In order to work properly, the freezer must keep its temperature below –18°C (0°F). The big problem with frozen food occurs when it thaws — fully or even partially — as this allows micro-organisms to get moving, growing and reproducing again. Bear in mind, many micro-organisms can reproduce in temperatures a person would still consider freezing cold. Peas and icecream show the effects of thawing and re-freezing well. If packets of

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peas are set hard and frozen solid into one or a few large chunks, you can assume the peas have thawed to some degree before becoming frozen again. What happens is that the thawing puts water between the peas and the refreezing turns the peas into one giant iceblock. Icecream reveals its history in a different way. Upon thawing, icecream melts and becomes partially liquid. When the icecream containers are shifted or stacked, the milky liquid is squeezed from under the lid and starts running down the sides of the carton. When the product is re-frozen, these ‘run lines’ become solid, stuck to the sides of the container where all can see them. Even where the icecream has not been re-frozen, you can tell if it is being stored incorrectly if, when you squeeze the container, you feel it yield under your grip. You don’t have to maul the icecream — just give the pack a gentle squeeze. It should be firm to your touch. Finally, if there are little crunchy slivers or crystals of ice in the icecream itself when you get it home and eat it, you can be sure it has thawed and re-frozen. To tell if there are problems with the shop’s freezer: ¥ Look for a thermometer on the inside

wall of the freezer. If you find one, does it show a temperature below –18°C (0°F)? ¥ Chest freezers have a ‘load line’ on the

inside of the rim. If any food is sticking out above the load line it cannot be expected to be maintaining the correct low temperature. ¥ If a food has been stored in a frozen state, then thawed, then re-frozen, there can be tell-tale signs left behind of this lapse in safety. Peas and icecream are two good indicator foods. If the icecream and peas appear to have been thawed and re-frozen, you can assume the other frozen foods in that chest or upright freezer have not been stored safely.

Other tips for frozen foods include: ¥ Buy icecream and other chilled or

frozen foods last, before heading to the check-out. ¥ Keep an insulated cooler bag in the

boot of the car for the trip home from the supermarket. If you don’t have a cooler with you, place frozen foods together to increase the cold mass and wrap them in layers of newspaper to slow them thawing.

THE GOOD EGG Can you tell if an egg has spoiled or ‘gone off ’? Some people suggest you place the egg in a cup of water and see if it floats: a floater is bad, a sinker is still good. According to the Egg Board, however, this test merely indicates that the egg has dried out a little on the inside. The only reliable test is actually to crack open the egg and inspect it. If the egg smells bad, it has spoiled and should not be eaten. You will recognise the unforgettable odour of ‘rotten egg gas’. Even if you’ve never smelled this before, you will instantly know not to eat the egg. If the yoke is runny — that is, not intact — that too is a sign that the egg may be nearly ‘off ’.

VEGETARIAN MEAT SUBSTITUTES Becoming a vegetarian doesn’t mean just leaving the steak and sausages on the plate and eating the vegetables and salad. It means planning meals where the protein comes not from animals, but from some vegetables (soy, lentils, various beans, chick peas, and the like), nuts, or cereals (‘gluten’ is a cereal protein found in wheat, for example). S u p e rm a rkets make available a range of vegetarian ‘meats’. Located in the frozen-

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food cabinets and deli sections, these products are often shaped and coloured to imitate meats, for example, the sausage shape or the hamburger pattie (rissole). You can throw them on the barbecue alongside your neighbour’s T-bone. Typically, these foods are made from ingredients such as soy protein, gluten or peanuts, together with seasoning and other flavourings. The good news is that vegetarian meats are less likely to contain viruses or bacteria such as E. coli, which are more commonly associated with real meats. The vegetarian a l t e rn atives are usually manufactured on premises where animal products are not processed. This physical distance acts to increase our protection from certain modes of transmission of micro-organisms. But vegetarian ‘meats’ still contain protein and moisture — an ideal medium for bacterial growth. In this respect they are just as vulnerable as animal meat. Salmonella, which is commonly found in eggs, chicken, duck and raw foods of animal origin, has also been found in non-animal foods like coconut, peanut butter, sesame seed products, and chilli powder. Our greatest risk is from poor hygiene among workers at the processing plant. Further risks appear, in common with animal meat, during transport, storage and display of the foods. All other aspects being equal, however, it is probably fair to say that the vegetarian ‘meats’ sold in your supermarket are less likely than animal meats to deliver a foodborne illness — although it’s not impossible. There are other benefits, too, when you choose more vegetarian meals. These products tend to be more environmentally friendly than meat. We conserve more of the Earth’s resources by eating ‘meat’ made from soy beans, for example, than if we grow the soy beans, feed them to cattle, and then eat the cattle. There is now a considerable body of scientific literature indicating that the array of

special plant nutrients found in foods like soy, if consumed regularly throughout a lifetime, may confer substantial protection against major diseases, including heart disease and some cancers.

‘USE-BY’ DATES Many supermarket items have ‘use-by’dates or similar warnings such as ‘use by’, ‘best by’, or ‘packed on’. Sometimes there’s just a date stamp, with no indication of what it stands for! The date is a guide to consuming the food or drink when it is at its peak in taste, aroma, texture and appearance. Manufacturers are usually being cautious when assigning a date to their products. In a quality sense, use-by and best-by dates are much more important for certain types of foods, including: ¥ milk, cheese, yoghurt and other dairy

foods ¥ bread ¥ eggs ¥ cakes and biscuits ¥ fruit juices ¥ seafood (smoked salmon, caviar and

other fish eggs) ¥ dips ¥ smallgoods ¥ pate.

The dates generally have more to do with food quality than food poisoning. In May 1999 a report from a camp in Albania revealed that about 200 refugees from the conflict in Kosovo had been hospitalised with food poisoning after eating salami imported from the Ukraine. It appears the salami was 11 years past its expiry date. The Reuters news agency quoted a doctor at the camp who said that food distributed as ‘humanitarian aid’ was becoming a common problem in the camp.

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A can in good condition can probably keep food safe to eat for many years, even decades. However, their use-by dates may still indicate a point at which their quality might be changing.

CHECKING OUT THE SHOP When a re t i red former chief executive of a major food-processing company went on an inspection of a large supermarket in Sydney in 1998, he found: ¥ blocked cold-air inlets in open-fro n t f reezer cabinets ¥ peas and other frozen foods which showed signs of having thawed and been re - f ro z e n ¥ food stacked above allowable height limits in open-top freezer cabinets. He was quoted in a newspaper as saying that supermarket managers were lazy and incompetent, and in constant bre a c h of food regulations: ‘All the big chains c a re about is the dollar’. He was conc e rned that the shift towards self-re g u l ation of the food industry would not work: ‘ T h e re is too much greed on the part of m a n u f a c t u rers and others’. Other industry figures were quick to defend the inspected supermarket and industry practices and accused the man of taking a ‘cheap shot’ at the food industry. Sometimes we use the term ‘food industry’ as though it was a homogeneous thing. In reality the industry is made up of a vast number of individuals and organisations who argue and differ about issues like food safety.

IS THAT MOULD? Most supermarkets have such a turn-over of stock that foods do not get a chance to go mouldy. Smaller supermarkets or corner stores may not be so lucky. So are those blue patches or hairy spores something to worry about? One famous mould produces the wellknown toxin ‘patulin’. This can turn up in apple juice, apple cider and fruits such as apples, apricots, cherries, grapes, peaches, pears and plums. Studies suggest it may be a carcinogen if consumed in sufficient quantities. Look out for white or coloured patches floating on the top of the liquid, or sticking to the sides of the bottle. Avoid or discard juice with a mouldy or musty aroma or taste. Bread moulds can appear after only a few days. At the supermarket check the ‘baked on’ or ‘use by’ dates of baked foods. If mould is scattered across several slices or the equivalent measure on an uncut loaf, give the whole loaf a miss, or give it to the birds. Don’t eat the mouldy slices. These days, preservatives are added to bread and bread rolls to keep moulds at bay longer. A more natural bread should be eaten within a couple of days unless refrigerated. However, refrigeration and freezing, though economical, really mess up the textures of some breads and make them less appetising. What should you do with mouldy foods? In most cases, avoid them, throw them away or put them in the compost. In particular, don’t buy or eat any juice, jam, tofu, jellies, cream, sour cream, cottage cheese or ricotta which displays patches of mould, as the mould’s toxins may have spread through the whole food.

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SUMMARY ¥ Canned and frozen foods are generally very safe, provided their packaging has not been

damaged. ¥ Never buy foods where the pack shows dents, holes, rust, leakage stains or smears,

deformation or bulging. ¥ Look for freezer ‘load lines’ and temperature gauges. ¥ Frozen peas and icecream containers are a good indicator of whether or not the

freezers have been working properly and at the correct temperature. ¥ Moulds can survive inside some packaged foods. In most cases you should throw them

away.

CHAPTER

11

DRINKS

DO DRINKS POSE THE SAME HEALTH PROBLEMS THAT FOODS PRESENT? We rarely hear about people getting food poisoning from having a beer, soft drink or a cup of coffee. Right? Well, no, that perception might not be accurate. In fact many of the mass outbreaks of foodborne illness are due to contamination of what we drink. According to United Nations — around one-fifth of the world’s population— estimates, almost one-and-a-half billion people lack access to a water supply which is clean and safe. And the United Nations, focusing on parts of Africa, the Middle East, India, China, Peru, Poland and England through the first quarter of the twenty-first century, expects the problem to get worse. The United Nation’s analysis estimates that water-related diseases currently kill between five million and seven million people annually, while as many as half the population of the developing world suffer from waterborne diseases. The good news is that, in a developed nation, it is a straightforward matter to improve your level of safety. Nothing fancy is required.

There are some very simple procedures which can help make many of our drinks safer: ¥ boiling — tea, coffee, herbal tea ¥ carbonation — the carbon dioxide

which delivers the bubbles in fizzy drinks also makes them slightly acidic and less attractive to bacteria ¥ alcohol and sugar are natural

preservatives. From beer to champagne, from soft drinks to tea and coffee, it is not hard to find a safe drink. The greatest health risk from these sorts of drinks comes from a dirty glass, or the use of contaminated ice blocks. We shall look at the riskier drinks: ¥ water ¥ bottled water ¥ fruit juice ¥ milk ¥ ice.

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THE TOWN WATER SUPPLY What could be more fundamental to a well managed city than a clean, safe water supply? Yet, over the last decade, many prominent towns and cities have faced a crisis over contamination of their water supply. The main culprits are: ¥ Norwalk viruses ¥ hepatitis A virus ¥ rotaviruses ¥ Giardia ¥ Cryptsporidium.

¥

Norwalk

The Norwalk viruses and other members of the dangerous calicivirus family are part of a wider group known somewhat unpoetically as ‘small round structured viruses’. They are associated with sewage contamination, poor food-handling, and problems in the water supply — the water we drink, wash our food with and the water we swim in (pools, lakes) — affecting foods such as salads and shellfish. In the body Norwalk can lead to gastroenteritis and food-poisoning, with vomiting and nausea, diarrhoea, headache, abdominal pain, and sometimes a light fever. Scientists believe it only takes a small dose of the virus to make a person sick. This is one of those health problems against which people in developing nations acquire a level of immunity while still young. In developed nations, however, it remains a major problem. According to the US Food and Drug Authority, Norwalk viruses account for around one-third of all gastroenteritis cases in that nation (excluding children under two years of age, who seem less likely to become sick). Water is the most common source, whether drinking water or the water we swim in. Many people acquire a level of immunity against Norwalk, although a relapse remains possible.

¥

Hepatitis A

Hepatitis A, like Norwalk, is a virus which may get to us through water, shellfish and salads. Outbreaks have been traced to ice, frozen strawberries, lettuce and raw oysters. Unlike Norwalk, however, food and drink account for only a small proportion of hepatitis A cases: person-to-person transmission is the most common route of infection. Again, human or animal faeces are the source, and poor facilities for personal hygiene — as sometimes found in institutions or overcrowded situations — create the perfect opportunity to spread. Chronic tiredness is perhaps the most noticeable symptom.

ALGAE MAKES ITS MARK Fresh water had to be delivered by tanker into Cape Patterson, Inverloch and Wonthaggi in the Gippsland region of rural Victoria in February 1998 following contamination of their water supply by blue-green algae. The summer heat, combined with run-off from agricultural land carrying fertilisers, had provided ideal conditions for the algae to spread rapidly and grow to vast numbers. Local health authorities issued warnings against drinking or even using the town water for food preparation. Residents were notified by radio reports and by a letter drop. Blue-green algae is the bane of many of Australia’s inland river systems. Some types are toxic. The blue-green algae problem we see in some Australian river systems and water supplies is not actually true algae at all, but bacteria that have similarities to them. Some of these bacteria can produce toxins which have the potential to harm the liver and nervous system, and can cause nausea, vomiting, abdominal pain and diarrhoea. It is a problem you can’t remove by boiling the water before you drink it or by running it through a domestic water filter. If your water supply is affected by blue-green algae or ‘cyanobacteria’, you will need bottled water.

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Children can bounce back from a dose of hepatitis A within a couple of weeks. In many cases they will acquire life-long immunity against reinfection with the virus

¥

Rotaviruses

If you travel overseas you may encounter certain viruses and bacteria which are not a major problem or issue back in Australia. A case in point are the rotaviruses. In the United States there is a great concern over rotaviruses which, in that country, are the most common cause of severe diarrhoea among infants and children. Few cases are life-threatening in developed nations, but it is believed rotaviruses account for something like one million deaths each year world-wide. The symptoms include watery diarrhoea, a light fever and vomiting. It takes only a few particles of virus to make a child sick. We pick up the virus in simple ways: contaminated cutlery, toys, dirty hands. Watch out for it in hospitals, day-care centres, kindergartens, and home. You can help keep the rotaviruses at bay by teaching your children to wash their hands before eating, and to keep their unwashed hands out of their mouths. Climate also plays a role: rotavirus illness is most common in winter in temperate zones, while in the tropics it occurs year-round.

¥

Giardia

Many of the waterborne pathogens affect our bodies for a week or two and then go their way. One which can turn into a chronic problem, lasting many months or even years, is Giardia lamblia. Neither a bacteria nor a virus, Giardia is a type of protozoa (single-celled animals), and a busy one at that. It is the most frequent cause of non-bacterial diarrhoea in the United States, and was implicated in the Sydney water scare of 1998: you don’t have to travel to exotic parts of the world to get Giardia. Giardia is measured in terms of numbers of ‘cysts’, or individual protozoa. Whereas it typically takes vast numbers of bacteria, for exam-

ple, to make a person sick, a single cyst of Giardia can do the trick. Giardia is more commonly found in children than adults. Adults seem to acquire a lasting form of immunity following earlier or childhood infection, although Giardia is more likely to become a chronic problem in an adult with compromised immunity (such as a person undergoing treatment for cancer) than in a child. One of the consequences of this illness may be an intolerance of lactose (the form of sugar found in milk). This can mean the patient may have to adjust his or her diet until the illness runs its course. Severe weight loss can affect some patients too. Generally, however, most people do not get sick from Giardia.

¥

Cryptosporidium parvum

The waterborne pathogen that is causing most concern is Cryptosporidium parvum. Like Giardia, this is one of the protozoa. It commonly infects a wide range of animal species, including herd animals like sheep and cattle. If these animals die in a water catchment area, the protozoa can get washed into the water supply, leading to contamination. This is believed to be one of the ways human outbreaks begin. Human faecal contamination is another source. This micro-organism has the power to threaten whole populations in a way beyond the reach of most food-poisoning outbreaks. Symptoms include severe watery diarrhoea, a low-grade fever and coughing. It only takes fewer than ten organisms, when swallowed, to make a person sick. Wh at ’s worrying is that Cryptosporidium is difficult to remove from a water supply. It’s very difficult to ensure widespread protection. It’s nothing new, and it affects all sorts of water supplies. In 1987 in the US State of Georgia, for example, 13,000 people became ill from drinking water infected with Crypto sporidium. The largest outbreak took place in Milwaukee during 1993 when an estimated 400,000 people may have been affected by contaminated drinking water.

BUT IT TASTED FINE! Also in 1998, four Melbourne public swimming pools — at Essendon, Northcote, Sunbury and Dandenong — were closed after 27 people came down with illness from Cryptosporidium. Don’t drink the water in swimming pools! Over a 14-year period in England and Wales more than 50,000 cases of cryptosporidiosis were recorded — 70 outbreaks involving multiple cases since 1993 alone. Most were waterborne. Investigators are presently looking for any patterns. At the moment the only clear revelation is that, in Britain, infections have been seasonal, peaking in spring and autumn. Some centres appear to have had more than their share of outbreaks, including Oxford and Swindon, Hull and Torbay. It would be helpful if we knew more about these patterns of activity so that we could better control Cryptosporidium.

IS BOTTLED WATER THE ANSWER? Australians spend nearly $300 million on bottled water each year. Do we need it? Why do Australians buy so much? Fashion is part of the reason, but so is taste — some of Australia’s water doesn’t taste all that great. But, as in most developed nations, the tap water is generally safe. Health authorities test local water supplies regularly to ensure its safety. Yet many people don’t trust them fully, suspecting the politicians and bureaucrats try to hide the bad news. But is bottled water any safer? In 1996 CHOICE magazine published results of its test of bottled water sold in Australia: all brands were found to be free of harmful bacteria. There is no reason to fear spa or mineral water if it is collected and bottled hygienically. (But it may come as a surprise that some brands of bottled water are filled from the mains water supply, usually with some additional filtration.) Is it worth the high cost? If you are concerned about the quality or safety of your drinking water you might be

In July 1998 a water crisis emerged in the alpine areas of the State of Wyoming before spreading to people across 13 states. Sixtyone people tested positive to E. coli O157: H7; 19 were hospitalised, and an additional 159 cases were suspected. Fortunately no one died from the infection, although things could have gone badly indeed, given the dangerous nature of this type of E. coli. It is believed the toxin first destroys blood vessels in the intestines, then passes into the bloodstream damaging blood vessels throughout the body. The symptoms include bloody diarrhoea and collapse. Blood clots can turn up in places like the lungs, heart, central nervous system and kidneys; the kidneys may fail and haemolytic uraemic syndrome (HUS) can develop. Up to 5 per cent of HUS cases are fatal! Broken fencing may have allowed animals into the alpine springs area where contamination of the water supply initially took place. People could not tell anything was wrong from the taste of the water.

considering getting a water filter. It is not a straightforward purchase. There are several types, working on different principles: distillation, a carbon filter, reverse osmosis, or ion exchange. Some points to consider: ¥ Each type of filter is good for removing

some problems, but will not deal with them all. For example, if it is bacteria or fluoride you are worried about, a carbon filter system is not the one to buy. Ion exchange filters will not remove all pesticide residues or chlorine. ¥ Many water filters are expensive to

maintain. They can use a fair amount of electricity or require regular replacement of the filter. ¥ If you don’t replace the filter regularly

you may in fact make your water worse! ¥ Some filters are bulky, particularly if

installed around the kitchen sink.

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¥ Some devices (distillers or reverse

osmosis filters) are very slow working. It can take a while to get yourself a drink unless you leave the device running. In the end, if you want to get rid of Cry ptosporidium or Giardia you should still boil the water. Fizzy bottled water is an even safer bet than still bottled water. The carbon dioxide turns the water slightly acidic, making life hard for any bacteria present. And if the water is fizzy when you open the bottle it is unlikely the bottle has been opened, or tampered with.

CRISIS? WHAT CRISIS? The crisis over the quality of Sydney’s drinking water, from July to September 1998, dominated that city’s news for the whole second half of that year. Was an e n t i re city, and a pending Olympic host-city at that, about to be laid low in bed with illness from G i a r d i a a n d C r y p t o s p o r i d i u m? Headlines shouted that Sydney had become a ‘Third World’ city. Sydney Wa t e r reimbursed schools, pre-schools and c h i l d - c a re centres for the cost of buying bottled water. In the wash up, it seems that while there is little evidence that people got sick: nonetheless there were casualties. Sydney Water — a private corporation, not a g o v e rnment agency — lost its chairm a n and its managing director; its water quality testing pro c e d u res lost credibility (Sydney Water admitted a ‘breakdown in quality c o n t rol’); control of the city’s water catchment areas was taken away from it; and its legal costs and related expenses soare d . After all the fuss, the city is still not s u re if there was a genuine health scare after all. But, on and off for at least thre e months as the scares came, were lifted, then re t u rned, the 3.5 million people of Sydney — and their visitors —boiled their water.

FRUIT JUICES We have built a solid foundation for the health of America’s families. But clearly we must do more. No parent should have to think twice about the juice they pour their children at breakfast, or a hamburger ordered during dinner out. (President Bill Clinton, 25 January 1997)

What is it about fruit juice that leads the US President to make this striking example of the threat to home and hearth? Isn’t juice simply a good, healthy product? Behind the president’s words was research by the Fresh Produce Subcommittee of the US National Advisory Committee on Microbiological Criteria for Foods (NACMCF) into a number of outbreaks of foodborne illness associated with fruit juices. The NACMCF concluded that ‘while the risks associated with specific juices vary, there are safety concerns associated with juices, especially unpasteurised juices’. Here we go again — it is the familiar issue raised throughout this book on the role of pasteurisation in giving us clean foods and beverages. Throughout many parts of the world, including the United States, the European Union, Australia and New Zealand, various products can be manufactured and sold unpasteurised, although their safety could be improved by pasteurisation. The NACMCF said that ‘the history of public health problems associated with fresh juices indicates a need for active safety interventions’. It also said that food processors and health inspectors should target two particular pathogens as the main threats in fruit juice: E. coli and Listeria monocytogenes. It singled out for special attention apple juice and the highly dangerous strain of E. coli known as O157: H7. It called for ‘urgent’research into understanding different types of juices (for example, citrus versus apple) and how the pathogens work in them. Clearly in the United States there has been a problem with the processing of fruit juices and with achieving a high quality of safety across

NATURALLY UNSAFE? the industry. The NACMCF recommended ‘industry education programs addressing basic food microbiology [and] the principles of cleaning and sanitizing equipment’. In Chapter 6 we explained how fruits must be treated with caution by the food industry as there are many opportunities for contamination in the fields or during picking and packing. Fertilisers of animal origin and dirty irrigation water are potential sources of pathogens. Washing the fruit may get rid of some bacteria, but others will only be removed by heat treatment such as pasteurisation. Yet not everyone wants to see universal pasteurisation. It can affect taste and texture, and is seen as ‘not natural’, which is a problem for a product which sells on the basis of being naturally healthy and good for you. It is not the purpose of this book to say there should be an end to unpasteurised fruit juices (or unpasteurised dairy products, for that matter). But consumers should be informed of the risks and should be able to know when they are taking a greater risk — that is, whether the particular juice in front of them is pasteurised or not. The NACMCF found a significant hurdle at this critical point: A significant problem identified by the Committee is that consumers presently do not have a means to clearly differentiate between unpasteurised and pasteurised products. Terms used to refer to juice products do not always have universal meanings, e.g. the term ‘cider’ is perceived to be an unpasteurised product whereas the term ‘juice’ is often perceived to be pasteurised.

In Australia and New Zealand, as in many other countries, the law does nor require fruit juice to be pasteurised. If you want to take extra care, choose a pasteurised brand.

¥

Kids with diarrhoea

Do your children frequently suffer from mild diarrhoea? Do they drink a lot of apple juice? Scientists are aware of a link between children’s diarrhoea and consuming large amounts

A Californian company, Odwalla Inc., pleaded guilty to violating federal food safety laws and paid a US$1.5 million fine for selling a batch of apple juice contaminated with the dangerous bacteria E. coli O157: H7. The juice was recalled after 70 people became sick and a 16-month-old girl died in Washington State during 1996. Cases of deadly haemolytic uraemic syndrome were recorded. The juice was unpasteurised and was made by company which promoted itself as a manufacturer of ‘natural fruit juices’. Fruit juice finally made a similar impact in Australia when, in 1999, a Salmonella outbreak hit the South Australian capital, Adelaide. Reports indicated that at least 500 people had been affected. After interviewing those who had become ill, investigations settled on Nippy’s fruit juices, where testing uncovered Salmonella bacteria on oranges. During the media frenzy which followed, Knispel Fruit Juices took action to recall Nippy’s Aussie Gold and Orange Grove fresh chilled fruit juices with a use-by date up to and including 31 March, 1999.

of apple juice. Research has suggested a number of hypotheses and it now appears that it is due to ‘sorbitol’, a natural component of apple juice and also the sugar in fruit which young children have difficulty digesting and absorbing. You might want to keep an eye on the possible link between apple juice and diarrhoea with any children in your household. Excessive drinking of fruit juices brings other problems, too. Juice is concentrated sugar, without the benefit of all the fibre that comes from eating the whole fruit. This sugar has just as many kilojoules as the sugar in soft drinks. Kids who suck on fruit juices through the day need to be reminded to brush their teeth several times daily. Their teeth are at risk of decay from the constant acidity and sugary bathing they receive. Vegetable juices, on the other hand, contain much less sugar and kilojoules than fruit juices, and are not fattening.

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MILK DRINKS Milk drinks suffer from the same risks as other dairy products, discussed in Chapter 5. They offer bacteria a high-protein environment in which to thrive, and must therefore be kept in the refrigerator. Bear in mind that the bacteria which lead to milk drinks becoming sour and spoiled are not the ones which can give you food poisoning, which occurs with the same old culprits: Salmonella, Staphylococcus aureus, Listeria monocytogenes and E. coli. Spoiling bacteria, while unpleasant, are generally harmless. Pasteurisation is the main technique used to make milk safe. Unpasteurised milk is still common in parts of Europe and through developing nations, so take care when travelling. In Australia it is not a problem, as all commercially sold milk is pasteurised. Be careful not to cross-contaminate milk with a spoon, for example, which has been used for serving other foods or left lying on a cutting board or bench. Bacteria love milk.

DIRTY ICE Your drink may be completely safe, but how about that ice cube floating in it? It is well

known than in countries where the water is likely to be contaminated we should avoid ice in our drinks too. Where the water source is clean, ice produced by commercial equipment has fewer problems than ice produced using freezer ice trays. This is largely because there is little human contact with the commercial process compared with the hand filling and emptying of ice trays. Dirty hands are a pathway to contaminated ice. Commercially produced ice has been found to be very safe. At a picnic or party, for example, drinks might be left to cool in a bathtub or cooler box filled with ice. It can be tempting on a hot day to drop some of these ice cubes into your drink or, for kids especially, to pop a cube into their mouth. This is not a good idea where ice has been in contact with the outsides of the drink containers or in contact with raw foods. And the container — the bathtub or cooler box — is probably dirty too. Ice is a good medium for contaminating otherwise safe foods. Sometimes food is in contact with the ice — prawns or fish, for example, after a day out fishing. As the ice melts, water flows around the food, distributing any pathogens from a ‘riskier’ food to other ‘safer’ foods.

SUMMARY ¥ Don’t eat or suck ice which has been used to cool food or unopened bottles and cans of

drink. ¥ Fizzy (carbonated) drinks are a safer choice than still (flat) drinks. This goes for bottled

water, too. ¥ In developed nations the town water supply is probably safe, although not always pleas-

ant to drink. You might consider getting a water filter. ¥ Water filters are not all the same and they don’t remove all potential problems: choose

one which eliminates the things you want removed. A poorly maintained water filter can do more harm than good. ¥ If in doubt, boil the water for one minute — although two minutes is safer still — and

allow to cool. Or you can drink tea, coffee, or a herbal beverage. ¥ Watch out for unpasteurised fruit juices. Check the label.

CHAPTER

12

TAKEAWAY FOOD SHOPS

TAKEAWAY FOOD IS BECOMING AN INCREASINGLY IMPORTANT PART OF OUR LIVES. In the three years from 1993 to 1996, Australians increased the number of meals they ate outside their homes by 57 per cent. Almost one-third of all the money we spend on food and drink goes on takeaway and dining out. If your own household habits are unhygienic, it just might be the case that you are in safer hands when you eat out. But, in the great outside world, you are placing your health in the hands of many, many people; some of these people will be lazy, will come to work while sick or may simply be ignorant of the exact nature and hazards of the bacteria and viruses they are dealing with. Maybe it is lunch time and you are in the local shopping mall, or perhaps you are on the highway, in unfamiliar territory, and looking for a place that serves a quick meal. What should be going through your mind as you make your selection? Which are the risky foods; and which are the safer choices?

HAMBURGERS In the hit movie Pulp Fiction, John Travolta’s character orders a steak in a flash ‘theme’ restaurant. The waiter asks him how he wants it. ‘Bloody,’ he replies. The waiter turns to Travolta’s companion. She orders a hamburger. ‘Bloody,’ she adds. While other more colourful events overtake these characters later that evening, there’s no doubt there is a real risk of food poisoning from eating a ‘bloody’ or undercooked meat hamburger. In 1992–93, E. coli O157: H7 bacteria were implicated in a major outbreak of foodborne illness traced to contaminated hamburgers from the Jack in the Box chain of fast-food restaurants across four US states. More than 580 people were affected with food-poisoning, having eaten one of the hamburgers or having been in close contact with someone who had. Of these, 171 people required hospitalisation, 41 developed the serious haemolytic uraemic syndrome, and four children died. All the patties had been prepared at the chain’s central processing plant before being

HAMBURGER OPRAH What have hamburgers and free speech got in common? In the United Sates, the common link is daytime talk-back television queen, Oprah Winfrey. A group of Texas cattlemen took Oprah to court, seeking damages of A$17.75 million, for comments she made on television about eating beef. In April 1996, on her own show, after hearing a guest speak about the possibility of mad cow disease crossing from Britain to the United States, Oprah reportedly said: ‘It has just stopped me cold from eating another burger. I’m stopped!’ The Texans did not like this. Following the show, beef prices fell by 10 per cent in the United States. And so they took Oprah to court. Oprah, however, did not go quietly. She defended herself with a ‘free speech’ argument which, after a well-publicised sixweek trial, ultimately swayed the jury in her favour.

chains and suppliers, you are taking little additional risk by eating the burger made at your local shop — and the product may well be tastier. Which is the safer choice: the hamburger or the steak sandwich? All other things being equal, choose the steak sandwich. For a safer burger: ¥ Look for a shop which keeps its burger

meat in the fridge or freezer until the moment it is thrown on the grill. ¥ Check the burger meat is cooked

thoroughly. The centre should not be pink but grey/brown; the juices should run clear, not bloody. ¥ You cannot treat a hamburger like a

steak. It must be cooked ‘well done’.

SALAD BARS shipped across the United States. This highlights the danger of thinking ‘the shop looks clean therefore the food is all safe’. It also shows how centralisation of food processing enables a single error to affect people over vast distances and in frighteningly large numbers. Indeed, it is possible, in the case of a product like minced meat, for a single hamburger pattie to contain meat from more than one animal — perhaps even hundreds — providing the opportunity for disease to spread widely from one sick animal. Of course, on the other side of the equation, a well-run central food-processing operation cuts out a number of risks that can occur in individual corner stores. A British study of pathogens in hamburgers found the patties coming to the takeaway shop from wholesalers or major distribution chains had better microbiological quality than those made on the shops’ own premises. Best results came from those burgers cooked straight from the frozen state, as opposed to those made from ‘fresh’meat. Although the microbiologically better quality product generally comes from the big

Self-serve salad bars have made great inroads into the typical unhealthy takeaway menu of hamburgers, chips, pizza and fried chicken. For that we should all be glad. Something refreshing, filling, nutritious and non-greasy is a welcome relief for those on the highway or just taking a night off from cooking to visit the local family restaurant.

N OT- S O - H OT DOGS 1999 was a bad year for hot dogs in the United States. Thorn Apple Va l l e y, of Southfield Michigan, recalled 13 million kilograms of hot dogs and luncheon meats because of positive test findings for L i s t e r i a m o n o c y t o g e n e s. Elsewhere, the Sara Lee Corporation in the United States recalled more than 1.8 million kilograms of hot-dog and deli-meat packages after discovering bacterial contamination. Report s of the estimated ongoing cost of the re c a l l to Sarah Lee put the figure upwards of A$116 million.

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Like smorgasbords, salad bars generate their own health concerns. In fact in Australia a code of practice was specifically developed for salad bars back in 1994 — a sign that a health problem had been recognised. There are two types of problem which the code confronts: how the restaurant or supermarket should display the self-serve salads safely; and how to minimise the risk of contamination from the many customers who will be dipping into the containers. Food inspectors, taking secret video of customers at self-serve salad bars, have seen people sneezing, coughing, licking the serving spoons, dropping the spoons then returning them to the containers, or accidentally dipping their jewellery in the food — all the health hazards you could imagine. Accordingly the code of practice actually sets out dimensions for the construction of a self-serve salad bar, including the use of a canopy or ‘sneeze barrier’ to cover the containers of food, and specifications for the size of the opening between the canopy and the benchtop. To give you an idea about how seriously the authorities take the issue of self-serve salad bars, here are a few of the standards which must be followed: ¥ Utensils must be designed to ensure

their handles will not fall below the top of the display container. ¥ Wooden utensils must not be used. ¥ Containers must be of a chip-resistant

material. ¥ Each container must have its own serv-

ing utensil. ¥ Containers must not be topped-up with

fresh salad. ¥ Food must be thrown out once it has

been on display for eight hours.

¥ After eight hours of exposure, the con-

tainers and utensils must be taken back to the kitchen for cleaning and sanitising. ¥ Salads, sauces and condiments contain-

ing potentially hazardous foods such as pasta, rice or cooked vegetables must also contain a mayonnaise or salad dressing which gives the dish an overall pH of less than 4.5. ¥ The salads and the display compart-

ments must be kept at or below 5°C (41°F) — and a temperature gauge must be located where customers can see it, on an external surface of the unit. It is quite a tough list. Have you seen the standards abused? Perhaps you’ve noticed staff topping up the containers rather than removing the empty ones and replacing them with fresh, full containers? Despite all the best preparations, it is still important that the supermarket or restaurant has staff stationed nearby the self-serve salad bar, ready to intervene when a serving utensil is dropped or a customer attempts to tidy up the display by hand. The presence of a supervisor is a good sign! When CHOICE magazine carried out a test in 1996 on salads from major salad bar chains (Coles, Franklins Big Fresh, Pizza Hut, Sizzler and Woolworths/Purity/Safeway), from six Australian capital cities, it found only 11 out of 61 sample salads were worthy of an ‘acceptable’rating both for quality and safety. Twelve samples were judged to be a ‘potential health hazard’, thanks to the presence of L i st eria monocytogenes, Staphylococcus or Bacillus cereus bacteria. Some of the salads were hardly ‘fresh’, being a week or more old and still being served! Some of these problems may, in fact, owe more to the interaction of the public with the

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Two of the greatest risk factors are foods that come from animals and those that are not cooked. The processes we apply to control food safety are mostly very effective, but when you find a food which combines both factors it is time for manufacturers and consumers to take special care.

MAKING A CHOICE AT T H E S ALAD BAR SAFER CHOICES fresh fruit fruit salad Greek salad ‘green’ or ‘garden’ salads tabouli vegetables

RISKIER FOODS bean salad chicken (cold) coleslaw eggs pasta salad pate rice salad salami seafood salad sliced meats smoked mussels smoked salmon soft cheese soft-serve icecream

salad bar than with contamination from staff and food handlers. Sneezing, children’s hands and cross-contamination are constant threats. Yet many of the salads are prepared in factories and delivered to the restaurant hygienically packaged — they have only to be opened and served. Nevertheless, you may wish to maximise your protection by making safer choices when eating at a salad bar. The table above shows, in no particular order, the relative safety of various foods from the salad bar.

¥

Mayonnaise

Mayonnaise is used in many commercial salads, particularly those in salad bars, for more than just reasons of taste. Properly prepared mayonnaise can act as a preservative, helping to slow down bacterial growth. This works because the mayonnaise is slightly acidic. Many other salad dressings work in the same way. So don’t be surprised to find your salads drenched in oily dressing or creamy mayonnaise! Mayonnaise is an emulsion of oil and egg yolk. The best mayonnaise uses olive oil, but other vegetable oils are commonly used. Flavouring comes from the addition of vinegar or lemon juice. These contain acetic or citric

acid respectively, and provide the anti-bacterial action. The mayonnaise has a tendency to separate if the oil particles are too large. To keep the concoction in its emulsified state we rely on commercial emulsifiers. On the other hand, a poorly prepared mayonnaise, without the sufficient acidity may, due to its high-protein ingredients, create a health hazard of its own!

DONER KEBABS The doner kebab (or yeeros) is like a salad roll, with slices of cooked chicken, beef or lamb assembled with salad ingredients such as lettuce, tomato and onion or tabouli, and glued together with hoummos and wrapped in flat bread. But the kebab is known as a potentially risky fast-food for several reasons. In some styles minced meat is used, and the dangers of mince have been discussed. In others the meat is sliced off a large, hand-assembled wad of sliced meat skewered on a metal spike or ‘spit’. Layer upon layer is built up on the spit, spiced and garnished with onion or other vegetables. The whole thing is designed to rotate in front of a fire or heating element which cooks the meat. When the outer layer has been cooked, it is ready to be sliced away and served. The health risks arise both from the large amount of handling which the kebab meat undergoes in construction, and from the possibility that the meat is not cooked thoroughly when removed and served. Being a thick wad, it takes a long time for the meat to cook to the centre. When there are plenty of customers to be served (at lunch time, for example) it takes care to ensure the kebabs are not being made with partially cooked meat. If the chef cuts too deeply while slicing off the meat for your kebab, you could end up with live bacteria from partially cooked meat. Salmonella is a key bacterial threat to kebabs. Other elements of risk arise with the making of the salad; the tabouli (parsley, tomato, chickpeas); the hoummos dip; and the final assembly of the whole kebab. There are many

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points at which cross-contamination or handling errors can introduce pathogens such as Staphylococcus aureus. The metal spit, if not cleaned properly, is ideal for passing bacteria. CHOICE magazine has tested the quality of kebabs on several occasions, rating onequarter of the 90 kebabs analysed as ‘unacceptable’ from a quality or health point of view. While there was no sign of Salmonella or Campylobacter, there were traces of E. coli, Listeria monocytogenes or Staphylococcus aureus in some samples. This indicated some faecal contamination had taken place. A British study, which tested 2538 kebabs from takeaways, Italian and Turkish restaurants, pizza outlets, fish-and-chip shops, and other retail premises across England and Wales during October and November 1995, found that 12 per cent were ‘unsatisfactory’, and 0.2 per cent were ‘unacceptable’ for consumption. Only five posed a real health risk to the consumer, but 307 were rated ‘unsatisfactory’ for having levels of bacterial contamination above desirable limits. Not all the bacteria were bad, but high levels of bacteria are an indication of an overall lack of good hygiene at work. The unacceptable kebabs showed different pathogens at work. One kebab had a high count of Staphylococcus aureus; three had high counts of Clostridium perfringens. The meat had spent considerable time on the spit. While most had been there for less than three hours, 5 per cent had been on the spit for 13–24 hours, 2 per cent for one to two days, and 11 kebabs had been cooking, on and off, for three to five days! In Australia, doner kebabs have had a hard time in the press. On a couple of occasions CHOICE magazine has reported on problems with this type of takeaway food. In one instance, sales of doner kebabs fell by an estimated one-quarter across the nation, representing a loss of millions of dollars.

Yet, speaking nutritionally, doner kebabs are one of the healthiest takeaway food choices — provided they are prepared properly. In response to the CHOICE reports, in 1997 the Turkish Chamber of Commerce launched a voluntary kebab standard, incorporating a quality assurance program. Those shops which abide by the standard were encouraged to display a sticker in the window: ‘Don’t do a doner unless it dons the logo with a capital D’.

RICE These days, rice occurs in an incredible variety of forms, foods and places. There is white rice, brown and ‘wild’; some specialty recipes create pilau or jasmine styles; rice is served as an accompaniment to Indian and Asian dishes, or served as a course in its own right as ‘fried’rice or combination rice. We also enjoy rice salads of many kinds, and we find rice dishes in restaurants, cafes, takeaways, pubs, petrol stations, self-serve salad bars in hotels and supermarkets. And then we eat rice pudding for dessert. If you find you are getting sick after eating meals from certain restaurants or takeaways, it might be the rice which is at fault, not the more exotic elements of the dishes. Where the food is self-serve, take a look and see if the staff simply tops up a near-empty rice container, or if they remove the container to the kitchen and replace it with a fresh one. Perhaps because it is so ‘wholesome’, rice can appear to be immune from problems. Yet there is a especially problem associated with cooked rice, especially in restaurants, takeaways and cafes. This problem is the Bacillus cereus bacteria. Bacillus cereus potentially haunts the pantry of the person who loves to cook. It turns up in many ‘dry’ ingredients such as flour, rice, custard, cornflour, cereals, spices and sauces, as well as on vegetables. It prefers alkaline foods to

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All other things being equal, a steak sandwich is usually safer than a hamburger!

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acid ones. This is more of a soil-and-dirt garden organism than one which comes from the person preparing or handling the food. The are two main ways we get it: ¥ through soil and dust finding its way

into the kitchen ¥ from dirt on vegetables.

Keep your kitchen clean and wash those vegetables! Like some other bacteria, it can also produce a toxin. However, unlike many, a poisonous dose of Bacillus cereus requires vastly more micro-organisms, so time is on your side (a little more) with this one. However, while heat kills the bacteria, it germinates the spores: cooking actually increases this risk. Once you have cooked rice either eat it straight away or put it into the fridge without unnecessary delay. Re-heated rice, such as that found in many takeaways, is a risky food. Do not eat cooked rice which has been left out at room temperature overnight. With rice the problem really only becomes a potential health risk because of the practice of many restaurants and takeaways of partly cooking the rice and putting it aside for a final heating just before serving or sale. Perhaps the chefs believe that a good final cooking will kill all harmful microbes. But this belief is wrong. If there is sufficient contamination of the rice, one of two types of sickness may result. The first type strikes within half an hour to six hours after eating the rice. It brings nausea and vomiting. The second type of illness leads to abdominal cramps and watery diarrhoea, first appearing some 6 to 15 hours after eating. Some studies have shown that restaurants and takeaways might keep the same partly cooked rice on the menu for more than 24 hours. A British test of cooked rice found hazardous levels of Bacillus cereus in around 1 per cent of samples taken from restaurants and the like, with worst results from those establishments which kept their partly cooked rice for more than a few hours.

PIZZA Pizza, being an assembled food, is the sum of the individual foods (and their risks) which have been combined. The good thing, is that pizza is cooked at a high temperature and, being thin, the heat has every opportunity to penetrate right through. Our pizza tips are: ¥ If you can see the cook, check that he

or she is wearing plastic gloves when handling the toppings. ¥ The cook should not handle the food

and collect your money, without washing his or her hands or changing gloves. ¥ Check for mould on the base of frozen

pizzas. ¥ You may wish to avoid ‘riskier’ toppings

such as fermented salami and seafood.

CHICKEN As mentioned in Chapter 7, we should always regard chicken as being potentially contaminated with Salmonella. Thorough cooking will deal with this. But consumers must watch out for dangerous signs and practices in the takeaway shop. Check the following: ¥ Does raw blood drip from one row of

chickens onto a lower row of almost cooked chickens? Cross-contamination can occur. ¥ Do staff handle cooked and uncooked

chickens without washing hands and utensils? ¥ Is the shop laid out in a way which

separates the cooking area from the preparation area? ¥ Is cooked chicken bloody or very

pink close to the bone? Pull the wings and drumsticks away from the body and check before you eat.

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PIZZA FALLS FLAT In 1994, Clydebank in Scotland was ro c k e d by a number of cases of scombrotoxin poisoning. The illness was traced to a number of shops serving pizza. Eventually the finger of suspicion landed on one part i cular menu item: tuna and pineapple pizza. The pizza had been supplied by a retail outlet to a large number of shops within a chain. Investigation showed that the pro b l e m a p p e a red to relate to poor hygiene and the practice of storing the tuna in opened cans. It is the same problem the consumer faces in their own home: take unused food out of the can and put it into a sealable plastic container for the fridge.

SANDWICHES: THE SAFE ALTERNATIVE? Sandwiches typically have less fat and no deep frying, and they contain salads and other ‘good’ ingredients. It can be easy to assume that because sandwiches are a healthier choice, they are necessarily the safer choice as well. Sandwiches’ big problem is that they lack the final protective process which cooking provides. The good thing about cooking is that it fixes many food safety problems. So is there a problem? In Australia, three surveys have shown that all is not well with takeaway sandwiches. In the early 1990s, the Western Australian Health Department tested 817 sandwiches of various fillings, purchased from locations across the state. They found high bacteria counts in two-thirds of these sandwiches. In the Australian Capital Territory, surveys from 1991 to 1993 found similar levels in half the sandwiches tested. In 1995, CHOICE magazine published results of its test on 89 pre-packed sandwiches, 30 of which were found to be of poor quality because of high overall bacteria counts, or the presence of food poisoning bacteria. The good news is that few of the sandwiches tested contained bacteria that could make a person sick. (Vegetables grown close to

the ground, such as lettuce or parsley, can send the plate counts to high levels because of harmless micro-organisms, without actually meaning the consumer is at risk.) However, a high bacteria count indicates that the safety process has broken down at one or more points, creating conditions where bacteria — good and bad — could multiply to large numbers. It is, therefore, partly good fortune that dangerous bacteria were not present. Poor storage can also be a key factor behind high bacteria counts. In general this means some shops are keeping pre-packed sandwiches in the temperature danger zone, or beyond their proper use-by deadline. Sandwich ingredients, or pre-packed sandwiches, should be stored or served out of refrigerated conditions. Don’t buy a pre-packed sandwich which is sitting on a shop counter at

PORK ROLL TO L L When hungry Melbourne diners purc h a s e d their $2.00 pork salad rolls from a number of Asian bread shops in March 1997, they would never had considered that one day they would share $750,000 compensation for their pains. Some were to receive a modest payment of $1000, while the most severe l y a ffected were paid as much as $80,000 each under a settlement negotiated on their behalf by a firm of class-action solicitors. It was not a small crisis. Around 770 people fell victim to Salmonella-infected rolls sold from a number of outlets across the city, but all originating from a Springvale food shop, World Hot Bread Bakery. Customers complained of abdominal cramps, weight loss and longer-term problems like reactive arthritis. Many required hospitalisation to deal with the Salmonella typhimurium bacteria. One customer revealed she was losing 1 kilogram each day for a week after being s t ruck down with the illness. She was unable to re t u rn to work for a fortnight, and described the event as ‘the worst experience in my life’. Another customer said the experience was ‘worse than childbirt h ’ .

WHICH SAN DWICH FILLINGS? The table below lists, in no particular order, some of the most common sandwich fillings and their relative riskiness. RISKIER

FILLINGS

MO D E R AT E

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cooked chicken

canned salmon/tuna

jam

egg

chicken loaf

Marmite/Vegemite

mayonnaise

corned beef

mustard

pate

Devon, other cooked meats

peanut butter

potato salad

dried vegetables in oil (e.g. tomatoes)

pickles

prawns (shrimp)

ham

salad and chicken

hard cheese

salad and mayonnaise

packaged sliced cheese

salami

salad

soft cheese

room temperature. Worse still, are the sandwiches sitting in a basket in direct sunlight? Once you buy your sandwich, eat it within an hour or put it in a cooler or fridge straight away. Which is the safer choice: the salad sandwich or the chicken sandwich? All other things being equal, choose the salad sandwich. Salads are a favourite, healthy choice for sandwiches, but, being natural foods, they must be well prepared. Lettuce may have been exposed to animal matures and inadequately washed. Lettuce also undergoes much handling during its preparation, from cutting and serving. Fortunately, bacteria have limited opportunities to grow on the leaf as its plant nutrients are locked in the leaf cells, giving no easy access to bacteria in search of food. This makes it hard for bacteria to multiply to large numbers. For similar reasons, salad vegetables like the tomato, cucumber, carrots and celery present minimal risk, provided they are washed and freshly sliced. However, once you add mayonnaise, egg or various meats to your salad or salad sandwich, the risk of foodborne illness increases.

WHEN SAFER CHOICES ARE IMPORTANT TO YOU Sometimes you cannot afford to take risks with foodborne illness. Here are our suggestions for minimising those risks, particularly where you are not familiar with the shop selling the food. Firstly, when at a fast-food outlet, order something which is not already sitting in a ‘hot box’ (bain marie) but which must be cooked fresh for you. You have no idea how long cooked food has been waiting around, nor if it has been held at a sufficiently high temperature to prevent the growth of micro-organisms. Secondly, your best weapon is choice. Choose safer takeaway foods, and safer fillings.

FOOD WORKERS SICK AT WORK While much of the food industry strives to ensure the food supply is safe, the product faces an uncertain delivery at the hands of thousands of cooks, waiters and other staff who prepare, assemble or simply hand over the meal. Many of these workers are very young and inexperi-

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enced; almost all of them are under pressure to get the job done. Officially, an organisation’s policy might be that a staff member should not turn up for work if he or she is unwell; the reality can be quite different. Harmful bacteria and viruses can be present on our skin, hair or in the mouth and nose. Illnesses such as diarrhoea, a cold, a sinus condition, bronchitis or a contagious disease all create a heightened level of danger to those who come in contact with the sick person. The signs of trouble are usually obvious: ¥ Do staff use gloves? If not, they should

only handle packaged foods. ¥ Do staff use tongs and other utensils

instead of their hands? ¥ Do staff wipe their noses or the sweat off

their skin? ¥ Do staff run their fingers through their

hair, or comb their hair? ¥ Do staff run their fingers through a beard

or moustache? ¥ Do staff cough or sneeze into the open?

Facial tissues and the humble cotton handkerchief are not always much of a barrier to micro-organisms. If a foodhandler sneezes into a tissue or handkerchief they should go and wash their hands straight away. ¥ Do staff nibble at food while they cook or

serve? Worse still, is anyone — whether staff or a customer — licking or sucking food off a spoon or ladle and then returning it into a platter of food or casserole? ¥ Do staff pick up dropped food, such as a

French fry, from the counter and put it back into the bag or on the plate? ¥ Do staff wipe grease and spills off their

hands with a cloth towel instead of washing at a sink?

Food handlers should not prepare your meal and take your money, unless they wash their hands or dispose of their gloves when moving from one to the other. How does a shopkeeper ensure that staff are in good health and have followed the rules and regulations? If a food handler has a Norwalk infection, for example, he or she should not work with food for 48 hours after diarrhoea has ceased. It is a difficult matter which requires ongoing vigilance and support in the workplace.

PICNIC TIPS When travelling you might choose to avoid the fast-food outlets and take your own packed meal from home. Check out these tips: ¥ The night before your picnic, ensure you

have sufficient ice, gel packs or freezer blocks ready in the freezer so that you can pack your cooler properly. ¥ On long trips, store your drinks in a separate cooler to your food. In that way you won’t be raising the temperature of your food every time you open the cooler to get a drink. ¥ You can pack some foods frozen: meats,

sandwiches, drinks. ¥ Wrap raw meat and chicken separately from all other foods. ¥ Don’t leave the cooler unzipped or lidless for more than a minute or two at any one time. ¥ Check occasionally to see that the kids haven’t got into the cooler and left it partially open. ¥ How are people going to wash their hands before eating? Pack some moist towellettes or a bar of soap and some water in a bottle.

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If you are planning to have a cake with your picnic on a hot day, choose one without custard or cream filling and minimise your risk.

TA K E AWAY FOODS: WHICH ARE SAFER? RISKIER

TA K E AWAY F O O D S

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chicken

fish

doner kebabs (yeeros)

French fries/chips

hamburgers (unless the meat is cooked thoroughly)

pizza (except with salami or seafood)

meat pies and sausage rolls

sandwiches (if freshly made and ingredients kept cool)

pizza with salami or seafood topping

steak sandwiches

salad bars sandwiches with seafood, mayonnaise, egg, pate, salami, cooked chicken, potato salad or soft cheese sandwiches (packaged) sitting at room temperature self-serve smorgasbord or public buffet-style dining ¥ If you are preparing a picnic, don’t bring

more food than you are likely to eat at the one meal time. Afterwards, throw away any meat/fish/chicken, other cooked foods or dairy foods which were not eaten at that meal. Don’t bring back

home a potential ticking bomb. These sorts of foods should be eaten within two hours once they are taken out of the cooler, or within just one hour if the day is hot (30°C/86°F or above).

SUMMARY ¥ The safest takeaway choices are not necessarily the foods which are best for you nutri-

tionally. ¥ Where possible, ask for food which will be cooked fresh for you. ¥ Pay particular care if you find your meal contains very pink, bloody chicken, hamburger

mince, or stale rice. ¥ Get out of there if the people serving or assembling the meal display signs of poor

personal hygiene, including handling food and money without washing their hands or changing gloves. ¥ Beware of any situation where there is no barrier between the food and the general

public. Make more cautious choices in this situation than you might otherwise make.

PA RT I I I

TRAVEL, PARTIES AND WHO LOOKS AFTER US

E. coli

salmonella

listeria

c ry p t o s p o r i d i u m

g i a rd i a

CHAPTER

13

ESCAPING THE TRAVEL BUGS

ONE OF THE GREATEST JOYS OF TRAVELLING IS TO EAT THE LOCAL FOOD. Sometimes this leads to sublime experiences — the Bearnaise sauce prepared in that village in France, the Pad Thai noodles in Thailand — and sometimes to wretchedness (‘I shouldn’t have eaten from that street vendor!’). From ‘Bali Belly’ in Indonesia to ‘the Curse of the Pharaohs’ in Egypt or ‘Delhi Belly’ in India … travellers have their own names for the classic case of food poisoning in another country. Can it ever be avoided? There was a Swiss man, hoping to cheat illness while holidaying in Egypt, who brought all his food with him from his homeland. For the length of his stay he ate nothing that he had not brought with him, and he drank only bottled mineral water. Within a week he had succumbed to illness. As you should understand now, the Swiss traveller had foolishly thought that his own food was the complete answer. In reality, it only provided partial protection. If you were a detective on the spot in Cairo, what do you think could have gone wrong?

First, the obvious flaws in his scheme: ¥ Did he brush his teeth with tap water

or potentially suspect local bottled water? ¥ Did he place his nice clean food on

unclean dishes, or into dirty cups? ¥ Did he use contaminated cutlery? (And,

if it was supposed to be clean, what did he, or anyone else, use to clean it?) And the less obvious faults: ¥ Did he bring the problem with him from

home? It’s quite possible there were harmful bacteria or toxins in his Swiss food. ¥ Did he store and carry the food

properly? Maybe something required refrigeration after first opening. Perhaps the seal on a package or can opened up. ¥ Was he already infected, with no

symptoms showing, before he arrived in Egypt?

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It is not just a problem when travelling through Asia, Africa or developing nations. Every nation has its problems, including ‘clean’ countries like Australia, New Zealand, the United States, and those against Europe. There are cultural ‘blind-spots’, such as: ¥ drinking local ‘potable’ water that

then introduces us to a new range of microbes to which we are vulnerable, but to which the local population is immune ¥ having picnics, where food sits out in

the sun all afternoon ¥ using local cheeses made from

unpasteurised milk and other foods ‘fresh from the farm door’ ¥ being in a hurry: re-heating leftovers in

a microwave oven for a quick snack, without allowing sufficient time for the heat to kill the micro-organisms ¥ being reluctant to stop socialising and

go and wash your hands ¥ resting your hiking shoes on the dining

table or near food preparation areas. In some cases the illness might not have been related to poor food hygiene, but might have had more to do with the testing holiday brew of too much sun, exercise, alcohol and spicy food.

WHICH COUNTRIES POSE THE GREATEST RISK? Experts warn that, in general, we are at risk whenever we travel to a country with a different climate or significantly different culture to our own. Warmer climates, in particular, call for greater care over food left out at room temperature; humid climates can promote the growth of moulds. In 1997 the British Consumers’ Association surveyed their members to find out how

often they became ill while travelling, and in what countries this occurred. Twenty-two thousand members replied to the survey. The countries where the smallest proportion of holidays were marred by illness were Western European nations such as Britain and Ireland (perhaps somewhat predictably, given that these were the home countries of the participants), Germany, Norway, Belgium and Denmark, along with Corsica, Hungary and Slovenia. The countries where survey respondents reported the greatest number of holidays affected by illness included China, India, Egypt, Morocco, Turkey and Indonesia. In the ‘average’ category were Australia, the United States, Greece, Canada, Spain, South Africa and Israel.

CRUISE BLUES It is bad enough to become ill while out at sea, but it becomes even more distressing when large numbers of fellow travellers also get sick and the whole cruise holiday seems to be under a shadow. In the case of one cruise ship in the western Mediterranean in 1995, the same illness showed up in passengers on four cruises over consecutive weeks. Something was really going wrong on that ship. But was it the crew’s fault? Over this time a total of 378 passengers reported sick with gastroenteritis. Symptoms included explosive vomiting and diarrhoea which lasted from as little as one day to as many as five days. The numbers of sick passengers increased, with more than half the total coming down ill on the fourth cruise. People did not all become sick on or around the same day. The first person to report sick did so on the second day of their cruise. People reported ill on most days it seems, so the fault clearly did not lie with a single meal, for example. Male and female passengers were affected but, curiously, fewer than 10 of the 378 victims were children.

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When the doctors were called in they suspected a virus lay behind these symptoms. But there were so many suspects it seemed a daunting task. Passengers were given a questionnaire about attendance at the captain’s gala dinner. Did they eat the prawns or the cold cooked meats? The raw vegetables or eggs? Did they drink tap water, have ice in their drinks or swim in the pool? The kitchens and the drinking-water tanks were tested. Inspection revealed a range of problems on the ship, including:

more affected than children). Perhaps the virus came on board with a passenger and spread quickly in the close quarters of shipboard life. Disembarking passengers had contact with new passengers both on the ship, during the change-over of cruises and in hotels which were associated with the cruises. One of the official recommendations to come out of the incident was that disembarkation should take place several hours before boarding, to prevent passengers from old and new cruises mixing and perhaps passing illness.

¥ inappropriate food handling, hygiene

and storage ¥ raw and cooked foods were kept close

together ¥ the rubbish area was too small, so some

rubbish remained in a food storage area ¥ bread rolls were handled without gloves

and were cut on boards used for chopping vegetables ¥ the dishwasher was incapable of main-

taining the necessary temperature for proper disinfection ¥ during one period of 24 hours no chlo-

rine (for cleansing) was detectable in the water supply ¥ some staff, including food handlers,

were known to have become ill but did not report their illness to management.

CHOOSING A RESTAURANT The hospitality industry suffers from a rapid turnover of staff. Low wages and the use of itinerant workers, back-packers wanting to make a bit of money before heading somewhere else, and ‘off season’ partial shutdowns, can mean fewer staff, poorly trained staff, reduced supervision, or simply stale ingredients. Look for these signs when choosing a cafe or restaurant, even in a large hotel: ¥ Is there refrigeration in the kitchen? In

developing nations throughout Asia, for example, much food preparation goes on in the back lanes behind the restaurants, in full sun. Seafood is left to dry on racks in the sun. ¥ Are the crockery and cutlery clean?

At the end of the cruises the management flew into action to cleanse the ship. All cabins and staff quarters — including walls and ceilings — were cleaned with a chlorine-based disinfectant. Soft furnishings from rooms where people had been ill were steamcleaned. At the end of the investigation, however, the cause of the outbreak remained elusive. Harmful bacteria were not detected in faecal specimens; the symptoms suggested a virus was at fault (as did the fact that adults were

¥ Are there signs of pest control — fly

and mosquito ‘zappers’, fans, covers over food left out on display? ¥ Are staff well groomed? ¥ Can you see that food is cooked fresh,

not left in a bain marie for hours?

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SAFE WATER Cryptosporidium is found in the water supplies of many countries, particularly in developing nations. For this reason it is believed to be a common and major cause of travellers’ diarrhoea. This parasite is resistant to chlorine treatment and, thanks to its minute size, can evade most filtration systems. It is a risk for everyone, but especially for children, the elderly and people with low immunity. Boiling the water will kill this parasite. It cannot be assumed that bottled water is free of Cryptosporidium because of the difficulty removing it if you don’t resort to boiling. The other common waterborne problems are enterotoxigenic E. coli, a bacterium, and Giardia lamblia, a parasite which settles in the gut. In a country like Australia it is estimated that up to 5 per cent of the population is infected with Giardia; in developing nations this estimate rises to 30 per cent of the population. It is something all travellers should be on the lookout for. Giardia, which was first detected as long ago as 1681, can be picked up from contaminated water — as in the 1998 Sydney crisis (page 92) — or from undercooked chicken and by cross-contamination. It is one of those illnesses which passes readily around the family or within an institution like a childcare centre. Even rainwater, stored in a tank, can have problems: Giardia is widespread in nature and can find its way into a rainwater tank. Chemical disinfectants, such as iodine and chlorine, can also clean up the water. They are available from camping stores in liquid form or as tablets. In general, iodine is more effective than chlorine against amoebic infection and viruses.

In another city or country it is not likely you will know a lot about how they treat the local water supply. You should be aware that mere treatment with chlorine will not remove many waterborne dangers, including Giardia and Cryptosporidium. Typhoid and cholera viruses will, however, be killed by chlorine treatment if the water treatment plant is operating properly, so it is not a waste of time by any means. In fact chlorine is highly effective against a whole host of problem bacteria, viruses and parasites.

BOTTLED WATER: IS IT SAFE? The traveller relies on being able to find and buy clean, safe, pure water. Is it reliable? There have been press reports from Asia of factories putting ordinary tap water into bottles or using the same plastic bottles over again. To maximise your protection: ¥ Check the seal is intact. ¥ Check the condition of the bottle. Is it

chipped, badly scratched, or is the printing/label partly removed? ¥ Buy the carbonated (fizzy) version

instead of ‘still’ bottled water. (The carbon dioxide which provides the bubbles also renders the drink slightly acidic, making it harder for bacteria to thrive.) ¥ It is also more obvious when fizzy

drinks have been opened or tampered with: the bubbles are a sign that the packaging is intact. ¥ Read the label. Terms like ‘pure water’

or ‘table water’ can mean the water has simply come from the tap.

TIP

To kill Giardia you must boil water for at least one full minute; three minutes is better. This means using a kettle or electric jug which doesn’t switch itself off as soon as boiling point is reached.

W H AT TO DRINK? WH E N

T H E WAT E R I S S U S P E C T

W H AT

T O AV O I D

Bottled water, particularly carbonated

Iced tea

Tea or coffee (made with boiled water)

Freshly squeezed fruit juices

Bottled or canned carbonated soft-drinks

Milk drinks, including milk shakes, shakes and smoothies

Beer

‘Slushies’ (cordials make from a mush of partially frozen flavoured ice)

Wine

Fruit punch

Champagne or other sparkling wine

Cocktails containing fresh fruit Anything with ice in it

It can be safer to drink straight from a freshly opened bottle or can than out of a dirty glass. Ask for it to be opened in front of you. However, the outside of a can or bottle might be contaminated, so use a straw or wipe down the drinking surface first. If you order a drink and it is served with ice, think about getting a fresh drink. Yes, you might feel weak sending the waiter back to the kitchen — but you’ll also feel weak if you get sick. Of course there is always the risk that the waiter will simply pour the old drink into a new glass, and the problem remains. If you have the money, and do not want to take unnecessary risks, buy a new drink. Ask the barman, or person serving, to leave out the ice.

¥

Can you trust hotel water?

One of the traveller’s abiding suspicions is whether or not to trust the hotel’s tap water. In many parts of the world it can come as a relief to enter the doors of a big hotel, to feel the first blast of the air-conditioning and to be shown into your peaceful, clean room. Surely here, at last, you can stop the stress of worrying about the food you eat and the beverages you drink. After all, isn’t that part of what you’re paying for? It is rare to find any research which puts this hypothesis to the test. However, one study reported in the Bangladesh Medical Research Council Bulletin in December 1987, did just this. The team took 1034 samples of

water from 18 hospitals and 44 hotels in Dhaka, the capital city of Bangladesh, and from three surrounding towns. The water came directly from hotel water reservoirs, and hospital kitchen and bathroom taps. They were looking for faecal and other bacterial contamination. What they found was that even in the fourand five-star hotels and the best hospitals there were times of the year when the water was contaminated. In general, water contamination rates were worse in summer and the rainy season, than in winter. On average, 90 per cent of the water supplies examined were unsatisfactory from a health perspective. In the best hotels, and one private hospital, the water was found to be free of faecal contamination in both summer and winter, but some failed when tested during the rainy season.

¥

Making drinking water safer

If you are backpacking, trekking or travelling off the beaten track, you should take your own water purification system with you. After all, there is only so much beer, wine or soft drink which most of us can stand! There are two main ways of treating water yourself: 1. Boil the water, and keep it at boiling point for three minutes. If you are at a high altitude (like the Himalayas or Andes), keep it boiling for a minute or two longer.

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2. Use a chemical. There are two common chemicals used to clean drinking water: tincture of iodine, and tetraglycine hydroperiodide tablets. Both chemicals will purify water against the main problem bacteria, parasites and viruses. Chlorine chemicals are often used too, but they are not as effective or reliable as the others. You can obtain the tablets or liquid from chemists, sports and camping stores. Follow the instructions on the pack for the number of tablets or drops per litre of water. Generally the number increases if the water is cloudy, very cold or dirty. You must leave the water to stand for something like 30 minutes before the process is complete and the water is ready to drink. Filtration will also afford you some protection. Take along a piece of cloth which can be used as a filter. Hold it over a container and pour the cloudy or dirty-looking water through it so as to remove some of the sediment and any insects, sticks and other foreign objects. In the shops you’ll see portable water filters which claim to purify water. Unfortunately their claims are difficult to test, so stick with the methods mentioned above.

¥

Not forgetting baby …

Travelling with a very young baby can be fraught with stress and concern. The safest drink for baby is breast milk. When planning your trip, you might consider delaying weaning the baby until after you return. That makes life easier — at least in one respect! Certainly avoid giving babies the local cow’s, goat’s or sheep’s milk, or fruit and vegetable juices. If bottle feeding, get yourself a sterilising system which is portable, and obtain any necessary adapters for the local power supply and plug configuration.

PROBIOTIC AID Travel can upset the digestive system, with diarrhoea, abdominal pain, flatulence, nausea or constipation. What, apart from medicines, can the traveller use to help deal with this? Some people claim that yoghurt is the easily obtainable, local answer. Yoghurt is made from milk which has been fermented with a bacteria mix (called a ‘starter culture’). The bacteria change some milk sugar (lactose) into an acid (lactic acid). This gives yoghurt its creamy taste and texture. The milk can come from any one of several animals, including cows, sheep or goats. But not all starter cultures are equal. Those looking for health benefits often choose yoghurt containing a culture of live bacteria such as Lactobacillus acidophilus, Bifidobacterium bifidum and/or Lactobacillus casei. There is some evidence (but no proof) that these cultures, preferably used together, may help keep your insides healthy by maintaining or even restoring the balance of bacteria in the digestive tract. Another type of product — a sort of fermented yoghurt-style drink — uses Lactobacillus casei in a similar way. Such products are called ‘probiotic’. This really means that something alive and arguably beneficial for our health has been added to a type of food or drink. Bear in mind, if you want to try the probiotic strategy, that the bacteria must be alive if they are to do anything. If the yoghurt or probiotic drink is left unrefrigerated, has been exposed to sunlight or ultraviolet light, or has been stored for a long time, the bacteria will have declined so substantially in numbers that there is no point in consuming the product. Buy from the shop’s refrigerator and look for a use-by date at least two weeks away.

TIP

Boiled water can taste bland and unsatisfying: try adding a little salt for taste.

W H AT TO LOOK OUT FOR WHEN ON HOLIDAY One of the great travel experiences is to eat the local food, and we certainly don’t suggest that you miss out. Sometimes it’s worth taking risks which might, in other circumstances, seem careless. In addition, you might not want to offend a kindly host. Be wary of alcohol. It has a minimal risk of causing food poisoning, but can affect your digestion, particularly in combination with too much sight-seeing, heat and spicy food. RISKIER

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Unbottled water

Bottled water

Ice in drinks

Bottled, carbonated soft drinks and bottled juicesAsk for drinks to be brought to the table in unopened bottles. If you think this would be offensive, at least ask that there be no ice in the glass.

Food which is presented in contact with ice Raw salads Undercooked minced meat (e.g. check kebabs) Prawns/shrimp Oysters and mussels Raw fish (e.g. sushi and sashimi)

Fruit which requires no washing (oranges, mandarins, grapefruit, banana and others with a thick skin)

Unpasteurised milk (as milk, cheese or yoghurt)

Cooked foods. Look for casseroles or curries cooked in a stock-pot, or cooked vegetables.

Freshly squeezed fruit or vegetable juices

Hot noodles, pasta or rice

Fruit which requires washing (grapes, apples, peaches, apricots, pears) unless you use your own supply of bottled water to clean it

Icecream or gelati in a sealed pack

Icecream or gelati served in a cone or cup Smorgasbord meals Cooked foods left in a bain marie for many hours. Breakfast should be all right, but be wary if the food could have been there from breakfast through lunch and even to dinner time. Cooked foods served by hand. Watch for noodles, pasta or rice served by the handful instead of by utensils. Cooked rice which has been left to turn cold Salami and sausages (fermented, not cooked ones: see Chapter 5) Dishes using raw egg Alcohol (It has a minimal risk of causing food poisoning but can affect your digestion TIP

One strategy, for the traveller with an upset tummy, is to eat good quality local yoghurt as a digestive aid. (You can also prepare for travel by eating well and building up your immunity beforehand.)

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SALADS: A DIFFICULT CHOICE Salads are seen as a healthy choice. And on holiday, when there is the temptation to overindulge in rich foods and treats, we want to restore some sense of nutritional balance by eating plenty of salads from buffets, smorgasbords and at pubs and hotels. In Chapter 6 we discussed the risks attached to salad vegetables and raw, premixed packaged salads. Salads remain one of the riskier foods for travellers, because vegetables easily pick up contamination in the fields where they are grown; during transport, packing and processing; and they are handled

repeatedly, by many different people. Cryptosporidium can pass to salad vegetables from contaminated irrigation water or when the vegetables are washed and cleaned. Giardia has also been detected on salads. If you have any doubts about the hygiene of a restaurant, hotel or staff, it may be best to avoid the salads and choose cooked foods (meat and/or vegetables) instead. Under similar conditions, give the fruit salad and fresh, sliced fruits a miss. Choose instead to peel a piece of whole fruit. At the time of publication, news came of three deaths in the Newcastle region of New South Wales from listeriosis, with fruit salad the apparent culprit. It seems that at least a couple of the victims were elderly.

SUMMARY ¥ Learn the danger foods. At the very least memorise the ‘big four’: tap water/ice,

salads/fresh juices, uncooked seafood, unpasteurised dairy foods. ¥ Choose sealed bottled drinks. No ice. ¥ Choose carbonated and boiled drinks ahead of ‘still’ drinks. ¥ Clean your teeth with bottled water, not tap water. ¥ If you are suspicious of the water quality, or you have low immunity, do not rely even

on bottled water. Boil the water for at least three minutes and allow to cool. ¥ Some bacteria and viruses thrive in situations where people are in close contact over a

number of days: cruises, camping grounds, residential courses run in institutions. Be especially careful under these circumstances.

CHAPTER

14

IT’S MY PA RT Y …

PARTIES AND CATERED EVENTS BRING FAMILY AND COMMUNITIES TOGETHER TO SHARE IMPORTANT EVENTS, OR SIMPLY TO ENJOY EACH OTHERS’COMPANY. It could be the football club barbecue, a school or church function, a wedding or camp. Sadly, in some cases, they leave a bad taste in the mouth when guests report sickness over the next day or so. It is not uncommon that parties are a source of food-poisoning outbreaks. Parties involve catering and storage on a scale that exceeds the capacity and experience of many households — and, at times, commercial operations — to operate within the rules of safe food-handling. One of the practical difficulties is having a large number of foods ready at the same time. Often this means storing some dishes for many hours beforehand. The fine weather that is ideal for summer picnics and barbecues is also the temperature danger zone. Add to this the problem of contamination by food handlers and guests, and you have a potent situation.

COOKING IN ADVANCE Even at home, when you are preparing the food for a party, you might want to cook some of the dishes ahead of time so that you have the freedom to talk with your guests as they arrive and to lavish extra care and detail on one or two particular courses. But how can you ensure you are not creating a food poisoning risk? Some of the things to watch when preparing meals in advance are: ¥ Keep all refrigerated components in the

fridge until you are ready to use them. Don’t be tempted to leave them out on the bench while you get on with other parts of your preparation. ¥ If meat, for example, needs defrosting,

make a start the day before. In this way you can defrost the food in the fridge. Alternatively, use a microwave oven to defrost the food before cooking it. ¥ Remember to wash your hands before

handling different types of foods.

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¥ Use separate cutting boards and

utensils (see Chapter 18). ¥ Don’t leave ‘risky’ foods (including

meats, seafood, eggs and dairy), whether cooked or raw, in the ‘danger zone’ from 5–60°C (40–140°F) for more than two hours, or only one hour if it is a hot day or the room temperature is very high (30°C/85°F or above). ¥ Invest in a cooking thermometer so

that you can check the internal temperature of foods. More specifically, when you cook food in advance of the meal, you can: ¥ Keep it hot. Leave it in a conventional

oven so that the internal temperature of the meal is always at 60°C (140°F) or above. This might mean the oven temperature should be set at around 95°C (200°F). Cover the meal with aluminium foil to help prevent the top getting burned. The meal might still dry out, however. ¥ Get it cold. This means the food temper-

ature must drop below 5°C (40°F). At the party you can serve it cold or reheat the meal to 75°C (165°F) before serving. If using a microwave oven, rotate the meal so that is cooks evenly. Check with the oven manual so you know how long to cook the food, what power setting to use, and how long to leave it to ‘stand’ after the timer turns the oven off. (‘Standing’ time is essential to let the heat work its way into the centre of the meal, particularly if it is dense — like lasagne or a casserole — or large, like a chicken.) Don’t just put a large meal into the fridge. It won’t cool down quickly enough, and the insides of the meal will be at a good temperature for bacteria to multiply rapidly. This means breaking the meal down into smaller, flatter portions which can cool quickly and, later on, will reheat easily. For example, if you have a whole chicken or a Christmas

turkey, separate it into portions (drumstick, wing, thigh, breast, etc.); a casserole, pasta dish or stir-fry should be cut into small sections and placed in shallow plastic containers or small flattish bowls. If food will remain on the table for more than an hour or two, rig up a system to keep each ‘at risk’ dish either hot (above 60°C/140°F) or cold (below 5°C/40°F). For example, place seafood on a bed of ice; spread the seafood out rather than make a thick pile. For hot foods, use warming trays, chafing dishes or an electric crock-pot. If you don’t have these facilities, the best course of action is to serve ‘little and often’, bringing fresh supplies to the table as they’re needed, straight from the oven or fridge. Resist the temptation to top-up dishes at a buffet. The safe course is to remove the empty or near-empty serving dish and put a new dish on the table. In this way you are not mixing fresh food with the remains of food which has been sitting at room temperature for some time.

DEALING WITH LEFTOVERS Leftovers have their own charm. Curries, in particular, taste better the next day. And the day after a party is one day when you could do with a break from cooking. Leftovers, as you’d expect, have their own food safety risks. Risky leftover foods to watch include: cooked rice, seafood, chicken, and stuffing. Throw them away if: ¥ they have been left out of the fridge

overnight ¥ people at the party or meal used their

hands to serve themselves ¥ people used serving utensils from ‘risky’

foods in otherwise safer foods (like a green salad). You can protect yourself further by reheating leftovers for a sufficient period, where appropriate, rather than eating them

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cold. If you have any doubts about how the food was handled or how long it was left out last night, cook it up or throw it away. If you are planning a large function, consider contacting the local government health

inspectors early in the process, so that you are clear about your responsibilities and can raise potential problems (about the menu, the site, and so on) and obtain information to aid your planning.

SUMMARY ¥ Store prepared dishes in the fridge or at a high temperature. ¥ Defrost frozen foods in the fridge or microwave oven, not on the bench or under warm

water. ¥ When preparing dishes be particularly careful to avoid cross-contamination. Change or

wash knives and chopping boards regularly. ¥ Wash all vegetables and fruits. ¥ On the dinner table, don’t top-up near-empty serving dishes. Instead bring a plate of

freshly cooked food from the kitchen. Don’t mix old and new. ¥ When in doubt, cook any leftovers before eating them — or throw them out.

CHAPTER

15

SCHOOL LUNCHES

CANTEEN OR HOME-PACKED LUNCHES? School canteens get regular goings-over by the media for selling ‘unhealthy’ foods. Meat pies, sausage rolls, chocolates, chips and fizzy sugary drinks are often what children want. There is the tension of trying to give school children healthy choices, but also having to run a successful canteen which everyone uses and which, if not setting out to make money, at least does not lose money for the school. But a canteen lunch is made much closer in time to the lunch period than a homemade lunch. In comparison, the student’s homemade lunch could be sitting at room temperature — or worse, in the sun — for five or six hours. Do you know where your children keep their lunches? You might be surprised that some leave the lunches in the school bags on verandahs at outdoor temperatures. Of course it is also fair to ask the question whether a canteen lunch would necessarily be prepared to a higher standard of hygiene

than a homemade one. After all, school canteens are often operated not by professional caterers but by parents — although, hopefully, with trained leadership. The great advantage, as mentioned above, is that the canteenprepared lunches are eaten much sooner after they are made. Which is the more wholesome and safer choice? In Fe b ru a ry 1998 a soap company released findings of its survey into the microbial safety of school lunches. (Clearly the company, which commissioned a laboratory to perform the tests, wanted to gain publicity for its range of household disinfectants — a relatively new and booming part of the soap range. But the results remain interesting.) Forty school lunches, prepared by ordinary households for children aged 5 to 15, were tested. Under the test protocol, the lunches contained ingredients such as cheese, chicken, ham, processed meat, or a spread. The sandwiches were held in a room at an average temperature of 26°C (79°F) for threeand-a-half to four-and-a-half hours before

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being chilled to minimise further bacterial growth. And then they counted the bacteria: ¥ 12 per cent were contaminated with

Staphylococci (a cause of gastroenteritis) ¥ 5 per cent had unsatisfactory levels

of E. coli.

While it seems, from reports, that none of the sandwiches contained enough bacteria to be dangerous, it is clear that a measure of cross-contamination or poor handling occurred in the preparation of the humble homemade sandwich. There are a few simple steps to follow if you want to give your children homemade lunches. The same rules apply for your own packed lunches, but it’s more likely in the workplace that you might have access to a staff refrigerator.

¥ Wrap sandwiches to maintain freshness

and to prevent contamination from other unwashed items in the lunchbox. ¥ Don’t re-use wrapping, plastic film or

paper. ¥ Don’t put the lunch in the school bag

the night before. Use the fridge. Tell your children to eat their sandwiches by lunchtime. And tell them to throw away — or to show you, if you prefer — sandwiches or any part of their lunch which was not eaten at lunch time. Fresh fruit, biscuits and certain drinks (cordial, not milk or opened fresh fruit juice) can last all day. Milk or juice, if frozen when the lunch is packed in the morning, can still be OK for lunch. Use longlife drink packs. Sandwiches, too, can be f ro zen, although salad vegetables don’t respond well to freezing.

TIPS FOR PACKED LUNCHES CHILDREN AND ¥ Put the lunch in an insulated cooler bag, G A S T R O E N T E R I T I S not just a plastic or paper bag, or even an ordinary lunch box.

¥ Place a freezer block in the bag. Some

lunch boxes come with a freezer block installed. ¥ Think before you use leftovers from a

previous meal: Can you remember how many days you have had them? Have they been in the fridge? Were they left out on the bench for several hours after they were cooked? Be especially careful with leftovers — it might be better to keep them for eating at home where they can be re-heated properly.

It is common to hear people complain that one of their children has a bout of ‘gastro’ (gastroenteritis, or inflammation of the stomach and intestine). Symptoms include watery diarrhoea and, in some cases, vomiting, headache, fever or abdominal cramps. Symptoms start to appear within 24–48 hours and might last for only one or as many as ten days, depending on the micro-organism at fault. It is one of those illnesses which often turns up in institutions or where large numbers of people are in close quarters — nursing homes, boarding schools, child-care facilities, cruise ships — or at banquets and parties.

TIP

Fill and place a drink bottle (plastic — not glass) or carton in the freezer the night before school. It will become a freezer block to keep the lunch cool through the morning.

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For most of us gastroenteritis is little more than an inconvenience which passes. If you can keep replacing the fluids otherwise lost from the body by watery diarrhoea, then you should recover fully with no long-term problems. But we should not be complacent about it. There are many who cannot easily maintain a healthy level of body fluid on their own, becoming dehydrated and weak as a result. In developing nations, gastroenteritis is a common cause of death, often because there is poor access to sufficient good-quality drinking water. In developed nations those at risk include: ¥ people who cannot care for themselves

properly — babies, children, the frail elderly and those with dementia

¥ people with low immunity. They

may develop more serious conditions requiring hospitalisation. Health authorities recommend that parents or carers treat gastroenteritis by giving the sick person plenty to drink. With young children, especially, you should use a product known as oral rehydration solution — a powder which you mix with clean or boiled water to make a drink — available from chemists. Tips for avoiding gastroenteritis are: ¥ Wash your hands before preparing or

eating food. This is especially important for school children. ¥ Don’t share crockery, cups and cutlery. ¥ Clean benchtops and sinks regularly and

thoroughly.

SUMMARY ¥ Keep it cold. Use a freezer block and insulated lunch bag. ¥ Keep the lunchbox/bag in a room out of the sun. ¥ Wrap sandwiches. ¥ Watch out for milk, fruit juice and other foods which should be kept refrigerated. Check

the labels. Milk and juice can last the distance if frozen the night before. ¥ Be extra careful with leftovers. ¥ Wash hands before preparing or eating. ¥ Try not to share plates, cutlery or cups with those around you if they are unwell.

CHAPTER

16

FOOD ALLERGIES

THERE ARE CERTAIN WELL KNOWN FOODS WHICH HOLD SPECIAL RISKS — ALLERGY RISKS — FOR SUSCEPTIBLE INDIVIDUALS. While most of the population can eat these common foods with no ill effects, those with specific allergies to any of them can suffer a range of nasty symptoms. This is not a situation of food poisoning or foodborne illness caused by contamination of the food itself. Yet it is worth knowing the foods which are the most common allergens so that you can raise the question with your doctor if it seems a family member has a problem. Allergy is a response from the body’s own immune system to a substance in the food. Normally it is a protein or glycoprotein at fault. The allergen might occur naturally in the food — lactose in milk, for example — or might be there as a result of cooking, processing or contamination of the food or drink. The body’s allergic reaction is the formation of Immunoglobulin E antibodies which, after a number of chemical reactions, cause the release of powerful histamines and other substances into certain parts

of the body: skin, eyes, intestine and respiratory system. The result might be: ¥ eczema ¥ diarrhoea ¥ asthma ¥ vomiting ¥ swelling of the throat.

The reaction might be all over quickly, or, in the worst cases, can lead to death. The most important point is that very few people have a real food allergy. In Australia only around 1–2 per cent of the adult population suffer from a food allergy. The rate is similar in other developed nations. The rate of food allergy in children, however, is much higher. In infancy and early childhood (up to five or six years of age), an estimated 3–7 per cent of the population are affected by food allergy. Fortunately most children grow out of their food allergies by the time they reach school age.

WHO CAN YOU T R U S T ? Many others experience other adverse reactions from certain foods — coffee, chocolate, red wine, for example — without the problem being an allergy. A British study found that whereas approximately 20 per cent of the surveyed population claimed to suffer a reaction from one or more foods, upon diagnostic testing only 2 per cent of the total population showed a true allergic reaction to those foods.

WHAT ARE THE MAIN FOOD ALLERGENS? More than 170 foods have shown signs of causing allergic reactions. However, most cases of food allergy are accounted for by eight foods:

A Sydney woman, who knew quite clearly she had an allergy to pine nuts, was always c a reful to choose foods which would keep her out of harm ’s way. When sitting down to a meal at a classy restaurant attached to a leading art gallery, she decided to ask the staff to check her meal for pine nuts. H o w e v e r, as soon as she ate the first mouthful she knew the check had failed her: her throat swelled, her chest constricted and her eyes became puff y. Abdominal cramps soon followed. At another restaurant she had suff e re d the same experience, again after re q u e s ting that her meal contain no pine nuts. How careful do you have to be? Can you rely on restaurant staff to understand the seriousness of your food pro b l e m ?

¥ milk

¥ peas

¥ eggs

¥ lentils

¥ peanuts

¥ tomatoes

¥ soy

¥ chocolate.

¥ wheat ¥ shellfish ¥ fruits

Foods in this second group also have a way of turning up as add-ons to other foods, for example, a sprinkling of poppy seeds on the top of a bread roll.

¥ tree nuts.

These are the foods you would investigate first. The first three — milk, eggs and peanuts — are the major problems. Watch out for the various guises in which milk products appear: packet cake mixes, drinks, biscuits. Wheat poses a similar problem, as it is used in so many ways. Another seven foods are also significant allergens, but much less commonly problems: ¥ seeds — sesame, sunflower, cottonseed

(meal, not the oil), poppy ¥ molluscs ¥ beans, other than green beans

WHEN THE LABEL GETS IT WRONG The ANZFA re p o rted the case of a child with a milk allergy who went into anaphylactic shock upon consuming a ‘non-milk’ d e s s e rt. The milk product was not included on the label’s ingredients list, and the manufacturer did not intend it to be in the dessert . What had happened was that poor cleaning of manufacturing equipment on the processing line had allowed milk p roduct to contaminate the preparation of a non-dairy dessert. And the child’s a l l e rgic response followed.

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Peanut allergies are of great concern because the allergic reaction they prompt affects sufferers’ airways and ability to breath. This means it can be fatal in highly susceptible people. A study of more than 60 people at an allergy clinic attached to Cambridge University suggests that peanuts and peanut butter should be kept away from babies who show signs of allergy such as eczema, hayfever or asthma. It is an allergy which often reveals itself while we are quite young — mostly by the age of three — and, in almost all affected people, by the age of seven. Parents of allergy-affected children must be constantly on guard against the relevant allergens — reading food labels and questioning staff at restaurants and takeaways. Yet it is a very difficult task. A study at the Children’s Allergy Centre of the Royal Children’s Hospital in Melbourne, found that in 72 per cent of cases of allergic reactions among 200

THE HIDDEN HAZARD In 1997, a young female factory worker stunned her colleagues over lunch when she seemed to be experiencing a violent asthma attack in the staff dining ro o m . Her symptoms were so severe that factory first-aid officers called for emerg e n c y ambulance assistance. A helicopter was b rought in to fly the woman to hospital. It was a terrifying moment. Investigators found out that the woman had a known allergy to peanuts and she c a refully avoided them. At first glance her lunch did not appear to contain peanuts, yet they were there. The family member who had pre p a red the woman’s lunch included part of a chocolate bar as a t reat. Unfortunately the chocolate bar contained chips of peanuts.

identified children, the reaction occurred at home. In 42 per cent of cases the food label correctly indicated the presence of the relevant food allergen. That’s a lapse of the home guard. But in 7.5 per cent of cases of these allergic reactions the label did not reveal the presence of the allergen. And that’s a serious lapse from the food industry. The food industry is well aware of the health problems posed by these allergens. This knowledge places a high responsibility on it to label products clearly so that consumers are alerted to the presence of common allergens. Manufacturers must also take extreme care to ensure these allergens don’t accidentally end up in foods where they are not intended — the result of poor supervision leading to cross-contamination on the processing line. Other contamination may be deliberate. ANZFA has expressed concern that some manufacturers might be tempted to cut costs by substituting a cheaper ingredient than the one shown on the product label. If this were an allergen — such as peanut instead of another nut, for example — consumers would be caught unawares. There is also some concern in expert circles that the current experimentation with genetically modified foods might see the introduction of allergens into previously otherwise allergy-safe foods. In one documented case, scientists working on a modified soybean found they had introduced an allergen, found in Brazil nuts, into the soybean. At this point the company acted responsibly by reporting its findings and discontinuing that experiment.

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HOW CAN I FIND OUT IF I HAVE A FOOD ALLERGY? Doctors can determine if you have a food allergy using a skin/blood test. A tiny drop of each suspected allergen is placed on a needle prick on your skin. If the spot turns red or swells, the suspicion is raised that you have a blood allergy to that substance. It is a quick and relatively painless procedure, but not 100 per cent accurate or reliable. A more definitive result can be obtained from an oral challenge or elimination diet. This involves pulling your daily diet back to a

very basic, bland diet without any of the common allergen foods. You then re-introduce those foods into your diet and see if allergy symptoms appear. In the case of asthma, or where swelling of the throat has taken place, it is safest to re-introduce foods in the presence of a doctor. If you believe you, or a family member, might have a food allergy, you should discuss the matter with your doctor. If you or a child has shown any signs of an allergy to the more serious food allergens you must take extra care in what you eat, as well as ensuring you pursue the matter of confirming the situation.

SUMMARY ¥ Symptoms of suspected food poisoning might be symptoms of something quite differ-

ent: a food allergy. ¥ You can be tested to find out if you have any food allergies. Contact your doctor. ¥ Only around 5 per cent of infants and young children, and 1–2 per cent of adults, have a

food allergy, ¥ The most common of the dangerous food allergens are milk, eggs and peanuts.

CHAPTER

17

STORING FOOD

THE REFRIGERATOR AND FREEZER ARE OUR GREAT ALLIES IN STORING FOOD SAFELY. The most important thing to remember is this: the fridge and freezer do not kill harmful bacteria or other micro-organisms. Cold just slows them down. They can be slowed significantly. But when you want to kill harmful bacteria you have to heat the food. When you defrost your food, the bacteria reach a comfortable temperature and start multiplying faster. Freezing preserves the food against further growth of bacteria, protozoa, yeasts and moulds. Viruses stop multiplying when they are no longer on a living host. As well as slowing down the bacteria which can give us food poisoning, freezing also puts the brake on other bacteria which carry out the natural processes of decay and spoiling of food. Many types of spoilage bacteria are not harmful.

THE FREEZER: WHAT CAN IT DO FOR ME? The home freezer is a great ally in keeping food safe. Yet some myths about freezing and frozen food can hinder our proper use of the freezer. On the next pages the answers to the most frequently asked questions about freezing food.

¥

The likes and dislikes of freezing

In the freezer, raw meat and chicken last better than cooked meat and chicken, because they contain more moisture and don’t dry out as much. Low-acid vegetables — such as beans, cauliflower and carrots — freeze better than many others. Very moist fruits and vegetables — such as blueberries, watermelon, tomatoes and lettuce — will fill with ice crystals, bursting open some cells. This leads to the fruit or vegetable turning mushy when thawed.

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Egg yolks change their texture during freezing, becoming thick and gooey. This means they won’t blend with other ingredients as well as if you used a fresh egg yolk. Egg whites freeze well. Keep cans out of the freezer as their contents will expand during freezing. In some cases the can might swell or even burst open. Blanching vegetables involves washing and peeling them, then briefly (partially) cooking them in boiling water. Blanching stops the work of enzymes which might otherwise spoil the food. You can also blanch vegetables in a microwave oven. Chill the part-cooked vegetables in the fridge before packing them and placing them in the freezer.

THE REFRIGERATOR If you know the basic ‘anatomy’ of the refrigerator you can keep foods in better condition, for longer as well as safer.

There are different temperature zones within the refrigerator (and freezer). Essentially this is because cold air falls and warmer air rises. This means the coldest places are usually (though not always) on the lowest level of the fridge and freezer. The diagram on page 128 shows a cyclic defrost refrigerator. This type of fridge has a cooling plate running down the back wall, inside the compartment. There will also be a drip tray at the bottom of the fridge (outside the compartment) to collect any water run-off. The fridge relies on convection to move cool air around, resulting in some areas being warmer than others. A cyclic defrost fridge can ice-up, both in the freezer and along the cooling plate in the fridge. This means you might have to defrost the fridge from time to time. In contrast, a frost-free fridge does not have a cooling plate and does not rely on air convection to move cold air around. Instead, a frost-free fridge has a fan which blows cold air into the compartments. The result is a more even distribution of temperature.

FREEZABILITY OF COMMON FOOD T Y P E S FREEZE

WELL

raw meat

FREEZE

R E A S O N A B LY W E L L

FREEZE

P O O R LY

cooked meat

eggs in the shell

raw chicken

cooked chicken

mayonnaise

fish

beans

cream sauces

leftovers

grapes

lettuce

bread

canned food

peeled bananas

tomatoes

cauliflower

cucumber

carrots

watermelon

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You can make your vegetables last longer, and in better condition, in the freezer by blanching them in boiling water first.

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FREEZING FOOD: FREQUENTLY ASKED QUESTIONS

Q A

Q A Q A

IS FROZEN FOOD LESS NUTRITIOUS THAN FRESH FOOD? Some testing has shown that fresh vegetables, for example, contain more of certain valuable nutrients than the frozen product. However, fresh vegetables lose their goodness quite quickly — over a matter of days. If you tend to buy your vegetables fresh once every week or so, you might be surprised to hear that a good brand of frozen vegetables may actually contain the nutrients at higher levels than the tired vegetables in your fridge at the end of the week. Freezing, in itself, doesn’t destroy the nutrients. However, when defrosting, some juices may be lost, taking an amount of nutrients with them, vitamin B1 from meat, for example. To avoid loss of nutrients, you could start cooking the vegetables while still frozen.

DOES FREEZING AFFECT THE QUALITY OR TASTE OF FOODS? Yes. This is where fresh produce has it all over the frozen alternative. Texture, taste, colour and appearance are all affected by freezing. However, the sooner the product is frozen, and the quicker the process (such as ‘snap’ freezing) the better the result. Premium foods will go from the paddock to the freezer or cool room in a matter of just a few hours.

HOW SHOULD I FREEZE FOOD? Food will keep its natural colour and texture better if it freezes quickly and is well packaged. Slow freezing allows large ice crystals to form inside the food. These crystals can break through cell walls and turn the food mushy when thawed. Good wrapping keeps out air and keeps in the moisture. For good freezing, separate your food into small parcels — say two sausages — then wrap with ‘cling’ plastic or place in small, flat containers, and lay the parcels out in a single layer over a wide area inside the freezer so that they are immersed in the cold air. Stack the parcels only when they are fully frozen.

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Q A

Q A

WHAT ARE THE ‘BURN’ MARKS WHICH APPEAR ON MEAT WHICH HAS BEEN FROZEN? The first parts of meat to freeze are those areas surrounding the muscle cells. Once frozen, they pull water out of the muscle cells by osmosis, leading to dry patches which have the appearance of a burn. You get less ‘burn’ if the meat freezes quickly. Other burn marks may be caused if air has reached the food. For this reason it’s important to wrap food well for the freezer. Cut the ‘burned’ bits off the food either before or after cooking. Although not harmful, the texture of the burn area can be unappealing.

IS THERE A LIMIT ON HOW LONG YOU CAN KEEP FROZEN FOODS BEFORE THEY BECOME UNSAFE? If the food was safe to eat at the time it was frozen, it will be safe when you take it out again. However, food quality will deteriorate over time and it might taste awful when you finally dig it out. There is also some loss of nutrients, especially vitamin E, in food kept frozen for long periods (more than six months).

Q A

WHAT ARE THE SAFEST WAYS TO DEFROST FOOD?

Q A

CAN YOU FREEZE ALL FOODS?

The quickest, safe way is to use a microwave oven. If you defrost food in a microwave you should be ready to follow on and cook it fully as the oven will have commenced the cooking process while thawing the food. Don’t thaw the food under hot water — this, too, will begin to cook. Health authorities warn against thawing frozen food at room temperature. This is right in the ‘danger zone’ for bacterial growth. However, thawing your food by taking it out of the freezer only to place it in the refrigerator is a slow process — allow one or even two days for this. You need to be well organised and happy to plan your meals this far in advance.

Yes, but not all foods respond well to freezing.(See the table on page 125)

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There are different temperature ‘zones’ within a standard cyclic-defrost refrigerator, some cooler than others. Some refrigerators may have additional features for storing special foods.

Whatever type of fridge you have, the coldest part will be near the cooling plate (for a cyclic defrost fridge) or adjacent to the inlet duct (frost-free). Some frost-free fridges have a ‘fast chill’ zone at this point, designed to quickly cool-down food or drink. (In some cases any food or drink left in the fast chill zone too long might freeze, so be careful!) The temperature — even in an ideally set-up fridge — might range by as much as 6°C. It might be only 1°C near the cooling plate, but 6–7°C in a closed compartment on the door. Generally the door is the warmest

part of a refrigerator, so it is not the best place for milk or other highly perishable foods. Other warm areas are on shelves towards the front (that is, near the door). Some fridges have a heated butter compartment. If it works, you can spread butter straight out of the fridge. The downside is that the butter will not stay fresh for as long. In this enclosed compartment, usually on the door, the temperature will be around 18°C (64°F). There are other design features to the fridge. Generally there is a plastic or glass

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shelf at some point towards the bottom of the fridge. Underneath the shelf is a plastic bin — the crisper. This is where you should put your vegetables. Effectively the shelf becomes a lid on the crisper, trapping some humidity. The crisper is often placed at the bottom corner of the fridge at a point where it can pick up a little warmth from the adjacent compressor. It is designed to prevent the vegetables ever dropping too far in temperature, as freezing will damage their texture. Meat, being a highly perishable food, is best stored towards the bottom but above the plastic or glass shelf. This is one of the coldest parts of the fridge. Keep your seafood, chicken and other poultry, liver and kidney in this region as they all spoil quickly. Don’t leave the fridge or freezer door open too long – that is over 15 seconds. Surveys by refrigerator manufacturers have shown that a family might open the fridge door as many as 50 times each day, and open the freezer door 20 times. The internal temperature rises dramatically if the door is left open for half a minute or so. A fridge which begins the day at 2–3°C could end the day at 6–7°C after much opening and closing. The temperature can rise even higher if you live in a tropical area or where the outside temperature is above 30°C (86°F).

FRIDGE AND FREEZER TIPS ¥ Store cooked foods above uncooked

ones, so there can be no contamination (for example, dripping moisture or blood). ¥ Watch out for foods with strong aro-

mas. Wrap them and keep away from cream, milk and cakes which can pick up the smell. Where possible, use a plastic or glass container with a tight-fitting lid, rather than a plastic wrap. ¥ Unwrapped meats can be expected to

last longer than wrapped ones. Trapped moisture encourages growth of surface

micro-organisms leading to spoiling and sliminess. Unwrapped meat dries out on the surface, slowing microbial growth. Unwrapped meat, however, develops colour changes and loss of flavour, so it is a trade-off. Your fridge might have a ‘meat keeper’ area with a lower temperature. Meat will last longer, and in better condition, if it is removed from plastic bags or wraps and placed either in a plastic bin or in a plastic container with a loose-fitting lid. Don’t use a plastic container with a perfectly sealed lid. ¥ Don’t re-freeze thawed foods — they

have been in the temperature danger zone and any bacteria will have begun to increase in number. Either cook and eat the thawed food straight away, or put it back in the fridge (not the freezer) for up to 48 hours. You should not put away foods which were thawed outside the fridge, by hot water or by microwave. ¥ Buy a refrigerator thermometer so you

can check on the performance of your fridge and freezer. Place it inside in a glass of water. This gives a better indication of the temperature at the centre of food. ¥ Keep your refrigerator below 4°C

(39°F). ¥ Keep your freezer below –18°C (0°F)

¥

Fridges, freezers and power cuts

If there is a power cut and the freezer turns off, how long will the frozen food stay safe? It depends on how full the freezer is, whether the door is firmly shut and well sealed, and possibly also on the room temperatures. A full freezer, in good working order, should keep the food in good condition for up to two days. If only half full, the food will last only around one day. If your home loses power, check your freezer and do the following:

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¥ Ensure the door is fully closed. ¥ Move the food parcels and packages up

against each other. They will keep each other colder for longer. ¥ Put the meat and chicken on the low-

est level. If they thaw they could contaminate other foods with their ‘juice’. ¥ Only open the door for the shortest

have been contaminated by raw meat juices. As a general rule, never re-freeze thawed raw meat, fish or poultry, as bacteria will have been multiplying. ¥ If the power cut lasted for less than a

day, some partly defrosted foods should be all right to eat over the next few hours. Keep them in the fridge until you are ready to cook them.

possible time. ¥ If the problem lies with your fridge, and

not a power cut, phone a neighbour and ask if you can put some of your food in their freezer until the repairperson comes. Once the power returns: ¥ Re-freeze any foods which remain

partly frozen and icy. ¥ Throw away foods which have become

soft, which leak ‘juice’ or which might

Have you ever accidentally left the door of the freezer open overnight? What should you do? The food should still be safe in the morning, provided the freezer was continuing to work. Check for softness and thawing.

¥

Fruit and vegetables: fridge or freezer?

If some fruit and vegetables lose their quality when frozen, how should they be stored at home? The list below is a good guide.

FREEZING AND REFRIGERATING FRUIT AND VEGETABLES Avocados Bananas Beans, broccoli, Brussels sprouts, carrots, cauliflower, peas, squash, zucchini Mushrooms Onions Oranges, lemons, grapefruit, mandarins Potatoes

Tomatoes Watermelon

Room temperature. If placed in the fridge an avocado might not soften. Keep out of the fridge. Cooling causes bananas to release enzymes, blackening the skin. OK in fridge. Remove squash and zucchini from plastic bags. With other vegetables the supermarket plastic bags prevent wilting and loss of nutrients. Place them in crisper drawers. Store in the fridge in a paper bag. This lets them ‘breath’. Do not store them in plastic bags or the mushrooms will sweat and go slimy. Keep out of the fridge and away from light. They like air circulation. Room temperature. Take them out of the plastic bag or they will ‘sweat’, causing rotting. Place them in a paper bag, cardboard box or on a shelf in a dark, dry and cool place. Potatoes should not be stored in the fridge as this causes the starches to break down to sugars, and the potatoes will turn grey-black when cooked. Don’t put them in the fridge unless you want to delay ripening. Once cut, watermelon will spoil rapidly at summer room temperatures. Store in the fridge, unless uncut.

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HOW LONG WILL FOOD LAST? The table on page 132 is a guide to the maximum time you should store food in either the refrigerator or your home freezer. A chart like this is fraught with difficulty as so much depends on how the product has been prepared, processed, transported and handled by everyone at all steps of the way from the paddock to your home. How you and your family handle the food is also a critical factor. Still, an approximate guide is a help for everyone in making their plans for a safer kitchen. The table assumes the food is in good quality and safe at the time it goes into your fridge or freezer, and that your fridge and freezer are kept at the correct storage temperatures throughout. Where foods are packaged but unopened, follow the ‘use-by’ or ‘best-by’ date on the pack. Once opened, however, it becomes difficult to give a precise length of time for which the food will be unspoiled.

IN THE PANTRY

¥

Canned foods

Generally speaking, canned foods lose more of their nutrients than frozen foods during processing. This is partly because canned foods undergo heat treatment to make them safe. Canned foods can last for years, but you should plan to eat them within 12 months of purchase as their quality can start to deteriorate. You can expect canned fruit and fruit juices to hold onto about 75 per cent of their vitamin C for 12 months. Some canned foods should be kept for only six months. These are baby foods, soft drinks, fruit juices, and rhubarb.

When you buy canned food, always check for: ¥ rust ¥ corrosion along the seams (top, bottom

and side) ¥ dents ¥ swelling ¥ directions on the label. Some canned

meats (including some ham) and fish require refrigeration. Corrosion and dents might have opened the can to the air, thereby potentially contaminating the food or hastening its spoiling. If you don’t use the whole contents of a can at the one meal, it is safe to keep the leftovers. If you keep them in the can, however, oxidation will occur and the food might spoil or lose colour and flavour. (Oxidation won’t give you food poisoning!) To get the best out of all leftover canned foods, put them into a sealed glass or plastic container and place them in the fridge. Once opened, do not store acidic or salty foods — such as tomatoes and fruit juices — in their original cans. Such foods will actually eat into the lining of the can. Put leftovers into a sealable glass or plastic container and refrigerate. Check the use-by dates on all foods sold as ‘specials’. They might be cheaper because they are old and losing quality: texture, colour, aroma or taste.

¥

Dried foods

The things to watch for with dehydrated or dried foods are insect infestation, and in some cases, mould, affecting flour, custard powder, rice, pasta and the like. Place dried foods in sealed containers and store them in your pantry or food cupboard. You

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A bulging, swollen can indicates bacterial growth may be going on inside. Under no circumstances should its contents be eaten, even if cooked. Some bacteria can produce toxins that are not destroyed by heat.

R E F R I G E RATED AND FROZEN FOOD’S DURA B I L I T Y FOOD

R E F R I G E R AT O R

Eggs (in shells)

3 weeks

unsuitable to freeze

Eggs (hard-boiled)

1 week

unsuitable

Frozen pre-cooked meals

unsuitable to refrigerate

3 to 4 months

Fresh supermarket salads (e.g. macaroni, egg or ham salad)

3 to 5 days

unsuitable

Sliced cold meats (e.g. ham, corned beef, salami)

2 to 3 weeks (3 days if opened)

1 to 2 months

Frankfurts (hotdogs)

1 to 2 weeks

1 to 2 months

Soups

3 to 4 days

2 to 3 months

Stews/casseroles

3 to 4 days

2 to 3 months

Bacon

4 to 6 days

1 month

Sausages

1 to 2 days

1 to 2 months

Hamburger mince

2 to 3 days

2 months

Ham on the bone

1 to 3 weeks

1 to 2 months

Beef (steak)

2 to 3 days

6 to 12 months

TIME

FREEZER

TIME

Lamb (chops)

2 to 3 days

6 to 9 months

Pork (chops)

2 to 3 days

4 to 6 months

Veal

2 to 3 days

4 to 8 months

Meat roast (with bone)

3 to 4 days

6 months

Diced meat

2 to 3 days

2 months

Chicken/turkey

1 to 2 days

6 months

Fish

2 days

3 months

Prawns (shrimp)

2 days

3 months

Leftovers

2 days

1 month

Fruit

Varies

6 months

Vegetables

Varies

6 months

Packed frozen vegetables

Unsuitable

12 months

Fruit juices

7 to 14 days

6 months

Bread

Varies

2 months

Jam

12 months

unsuitable

Jars of commercial mayonnaise, mustard, sauces

12 months

unsuitable

Icecream

Unsuitable

2 months

Milk

5 to 7 days

unsuitable

Yoghurt

5 to 7 days

unsuitable

Cheese

1 to 3 months

unsuitable

Butter

8 weeks

unsuitable

Margarine

6 months

unsuitable

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must put the food into the container when you first open the packs in which they were purchased. If you leave a paper pack of flour open for a few days you might already have let moths and insects get inside. Check the seals are good. Dried foods can be kept, if unopened, for up to six months at room temperatures below 24°C (75°F). Store them in a cool, dry place out of sunlight. Once opened, dried or dehydrated foods can become moist and, at that point, must be treated like any other perishable food.

¥

Bottled and packaged foods

Have you ever seen swollen food containers? This can be a sign of spoiling through microbial growth. Unprocessed

cheese, fruit juices, yoghurt and made-up pastry are the sorts of packaged foods where you could encounter this problem. Bottled foods don’t show problems like swelling. On occasion bottles actually break due to some internal problem, such as excessive build-up of gas in fruit juices or homemade beers and wine. The great thing about bottles is that you can see what is inside, although that won’t help you pick a contaminated product, merely one that should be of good texture, colour and quality. Once opened, it is common for a crust to appear under the cap and around the rim of bottles of sauce, salad dressings and jars of mustard. It is not harmful (although it might not taste very good!). Wipe bottle openings from time to time to remove it. This will help maintain the seal.

SUMMARY ¥ Get a fridge thermometer and see that your fridge is operating at or below 4°C (39°F),

and your freezer at or below –18°C (0°F). ¥ Opened protein foods — like deli meats or fresh meat — will keep in the fridge for up to

three days. ¥ Leftovers will keep in the fridge for a day or two at most. ¥ Most canned foods should last at least one year unopened, and probably many years. ¥ Remove leftovers from the can and store in an air-tight container in the fridge. ¥ Keep dried foods, unopened, for up to six months. ¥ Don’t buy or eat from corroded, swollen, dented or damaged cans or packets. ¥ Don’t refreeze food which has already been frozen and thawed. ¥ Food which has spoiled or gone ‘off ’ (e.g. sour milk) is an issue of food quality, not

necessarily related to food poisoning. Watch for ‘use by’ or ‘best by ’d ates on labels and packaging.

CHAPTER

18

YOU AND YOUR KITCHEN

DO WE REALLY PRACTISE SAFE FOOD HANDLING TECHNIQUES IN OUR HOMES? To answer this question, a national survey was carried out in the early 1990s in the United States involving 1620 randomly selected people aged over 18. Interviewers asked the subjects questions designed to find out their level of knowledge about foodborne illness and how they prepared and cooked their food. The results were revealing: ¥ One-third of the people engaged in

unsafe food hygiene practices, such as not washing their hands before handling food, or failing to take precautions to prevent cross-contamination from raw meat. ¥ Many of these people ate raw foods

of animal origin, taking a risk with their health: 53 per cent said they ate raw eggs; 23 per cent ate undercooked hamburgers; 17 per cent ate raw

clams or oysters; and 8 per cent ate sushi. (Note: Oysters are more of a problem in the United States than in Australia.) ¥ Men were more often guilty of these

lapses than were women. ¥ The worst age group was 18 to 29

years. ¥ Those who were frequent cooks in

their households were more likely to have safer food practices. ¥ Those who had some understanding of

the types of pathogens and how food became unsafe were more likely to do the right things. The researchers reached this conclusion: These findings suggest that risky food consumption and preparation behaviors are common in the United States and that educational campaigns aimed at changing these behaviors may need to be targeted to specific groups of persons.

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HOW SHOULD I CLEAN MY KITCHEN BENCHES? Water on its own is not good enough — but you don’t really need disinfectants and expensive ‘anti-bacterial’ products. The most effective treatment for your benches and sinks is to wash them, after use, with detergent and hot water — and a bit of effort to physically wipe away food spills and grime. This will do more to remove bacteria than if you just splash around some disinfectant. Unless visible cleanliness is achieved, it is misguided to rely upon disinfectants to solve the problem. Don’t ignore kitchen sponges and cloths. These make ideal homes for bacteria, as they’re often wet, warm, dirty, and filled with little bits of food. Some points to remember on kitchen cloths: ¥ Change your kitchen cloths and

sponges well before they start to smell, look dirty, or become slimy. ¥ Experiment with types of dishcloth

which can go into the dishwasher and get cleaned thoroughly. Let them dry in sunlight, if possible. ¥ Once a sponge or cloth has wiped the

floor do not return it to bench-top use. Try using disposable paper towels for the floor. Soap companies are seriously marketing a relatively new product range: anti-bacterial soaps, dishcloths, sponges, wipes and sprays for the kitchen. In the United States it is a market segment worth over A$800 million annually. (No wonder the manufacturers want to get the rest of the world hooked onto these products too.) These cloths and wipes are impregnated with an anti-bacterial solution. However, after a few washes the active ingredient starts to disappear, and you need to buy another one.

But are these things necessary? After all, we’ve survived without them for thousands of years. And bacteria are everywhere, good and bad. Regardless of the hype, the reality is that good kitchen practices make these new products — even those that might dispose of some bacteria — unnecessary. For example, do your cutting on a clean board, not on the bench. Follow the tips for avoiding cross-contamination. Wash your hands. Most of the serious bacteria will be killed by adequate cooking. The use of such products might even be playing a part in helping bacteria become resistant to disinfectants. These small doses of anti-bacterial chemicals will not kill everything, so those that remain could gain a degree of immunity. When you think about it, it is futile to try and sterilise the world in which you live. If you use an anti-bacterial hand wash, you have to remember to use the hand wash to clean the tap before you turn it off, or you’ve got your old germs back! The final word is that these disinfectants are a fad, driven by marketing. Clean your benchtops after use with soap or detergent, and hot water. The key factor is not an expensive chemical cleanser, but physically removing all visible traces of food stains, spills and grime.

CUTTING BOARDS: WOOD OR PLASTIC? This is a debate which has raged for many years now. On the one hand, plastic boards are easily and readily cut by knives, leaving scars where bacteria can live and multiply. On this point wooden boards are arguably ahead. There have also been studies to suggest that wooden boards have anti-bacterial properties, while plastic boards trap bacteria. However, the plastic board, unlike a wooden one, can be shoved into the dishwasher

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WASHING HANDS: FREQUENTLY ASKED QUESTIONS

Q A Q A

SHOULD I WASH MY HANDS USING A DISINFECTANT? Disinfectant is unnecessary. Soap and hot water are enough. But, as we cannot stand to place our hands in water which is hot enough to kill bacteria and viruses, we have to wash for longer — try and wash for 30 seconds. Work up a lather on the soap. If you have been gardening or working on the car, it is a good idea to check under your fingernails too, and use the nail brush.

IS DRYING HANDS IMPORTANT? Yes. A study carried out at the Auckland School of Medicine, New Zealand, looked at the ways people dried their hands, how long they spent doing this, and how many micro-organisms were present on their hands afterwards. One of their findings was that wet hands — that is, not dried fully after washing — could still transmit a vast number of micro-organisms: about 60,000, compared to a mere 200 if the hands were dry. The water acts like a bridge along which microorganisms can pass from one person to another or to a surface.

where it will be cleaned thoroughly and effortlessly. (Note: A solid wood board can be washed in this way. It is only laminated wooden boards which are best left out of the dishwasher — they can split apart.) The US Food and Drug Authority has determined that, on balance, the plastic board is the better choice. Research has demonstrated that bacteria are more easily washed off a plastic or acrylic board than a wooden board. It also seems that while a good wash will successfully remove all bacteria from both plastic and wooden boards, test results show that plastic can be fully cleaned more reliably than wood. However, it is still acceptable to use a wooden board for most purposes, including meats, provided you wash it well and avoid cross-contamination. Do not use the same board for meat and vegetables. Glass boards appear a good solution too.

If you do not use a dishwasher, wash the board in hot soapy water and leave to dry in the air. Do not use a cloth towel. If you want to dry it quickly, it is preferable to use paper towels. Some health authorities also recommend that you disinfect your cutting boards once in a while.

PERSONAL HYGIENE Do not handle food or cook it if you have a cold or the flu. Of course, this might be an impossible rule if you are the only person going to do the cooking. In that case, get yourself a disposable face mask. Many microorganisms work their way from your face — wiped from sweat out of your eyes, or when you touch your moustache — onto your hands and thereby to the food.

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Wash your hands before handling food, cooking food and eating food. You should also wash your hands after handling raw foods, and before moving on to other foods. 2Researchers, by observing people washing and drying their hands, found that, on average, people spent about 4 seconds drying their hands if there were towels and about 15 seconds if there was an electric hot-air dryer. Better results came from using the blower than the towel, partly because of the extra time hands spent under the hot air. The researchers recommended that people working in food preparation would get the best results from a combined approach: 10 seconds using a clean towel, followed by 20 seconds of hot air.

¥

How often should you wash your hands?

(Take a big breath before reading this.) You should wash your hands: ¥ after going to the toilet ¥ before handling food ¥ after cleaning down the benchtops

and sink ¥ whenever you move from one broad

type of food to another (e.g. from meat to vegetables, or vice versa) ¥ when moving from raw to cooked meat ¥ after blowing your nose ¥ after touching your moustache, beard

or hair ¥ after touching shoes, gloves or any

clothing which might be soiled or dirty ¥ after handling money (which may har-

bour micro-organisms) ¥ after touching pimples or cuts ¥ after picking up used crockery and

cutlery

¥ after licking your finger (You might

have cleaned up the food spill, but you could be transferring a germ to your hands.) ¥ after putting a cigarette to your lips or

pulling the cigarette out of your mouth (saliva could be on your fingers!) ¥ after handling rubbish or touching the bin ¥ after handling any cleaning compounds

stronger than soap ¥ when you’ve finished preparing the

meal and are about to sit down to eat. Is this an impossible list to follow? It depends on what is at stake. If you really want to be careful about food poisoning — perhaps you have a special reason for being particularly cautious, such as looking after someone who is ill, very young, very old or who has reduced immunity — then you should set up your kitchen for frequent washing of your hands or it will be all too hard, a pain in the neck, and neglected as a result. It also means getting rid of old tea towels and dish cloths, the cake of soap and old pot scrubbers and scourers. Buy a liquid-soap dispenser and place it near the sink. Install a dishwasher if you don’t already have one (and if you can afford it). A dishwasher can use hotter temperatures for the washing water and will dry crockery and cutlery with hot air (although this feature might work well only on the expensive models). You can put your plastic cutting boards and some scourers and sponges into the dishwasher. And don’t worry about dishwashers wasting water. A modern dishwasher will use less water than the kitchen sink! Having washed your hands, you only risk re-contaminating the skin by wiping your hands on a cloth which has been used a number of times. Old tea-towels and dishcloths harbour micro - o rg a n i s m s. Commercial kitchens often use air-drying machines instead of towels by the sink. This might be

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too expensive or bulky for the home, but the issue remains the same: change tea-towels throughout the day. Rub your hands together and shake off any loose water into the sink. Paper towels are an improvement on cloth towels, as you use them only once before throwing them away. Hand washing is a chore, there’s no two ways about it. But if you look at the long list of ‘when to wash’, you can see that it can be broken down into three simpler rules:

¥ When you are preparing food, don’t do

any other activity. ¥ Don’t cross-contaminate your foods. ¥ Keep your hands on the food, not your

body or clothes. Leave it until after your meal to stack the dishwasher, put out the rubbish or tidy up around the kitchen. Make no room for crosscontamination.

SUMMARY ¥ Leave dishes, cutlery and cooking utensils to dry on the rack. If you use tea-towels,

change them regularly throughout the day. ¥ Use a dishwasher. They are hot, clean and surprisingly frugal with water. ¥ When you are preparing food, don’t do any other activity at the same time. ¥ Don’t cross-contaminate your foods. Clean your utensils and change chopping boards

when moving between different food types: raw meat, cooked meats, vegetables and fruit. ¥ Keep your hands on the food, not on your body, your hair or your clothes. ¥ Don’t handle pets in the kitchen or when preparing meals.

CHAPTER

19

THE BUSINESS OF FOOD

THERE HAVE BEEN BIG CHANGES IN THE WAY WE MANAGE OUR FOOD CHAIN. Some of these changes have occurred in our homes, on the farms, in the factories that process the foods, and in the supply and delivery network that moves the food from one location to another. Sometimes it seems the only thing that hasn’t changed is the way we chew and digest it!

QUALITY CONTROL Let’s go back a little, just to the end of World War II. The end of hostilities signalled massive changes in the lifestyles of the Western world. This included the rapid growth of huge farming enterprises; replacement of the corner store with the supermarket; and a gradual move over the next four decades from home food preparation and preservation to largescale food manufacturing, new frozen and chilled foods. Prior to World War II very few homes had freezers; many did not have refrigerators.

Milk and vegetables, meat and bread were produced locally, delivered daily and sold in corner stores. Many homes bottled homegrown fruit and vegetables for the winter months, hung onions in the shed, stuck pumpkins in the roof and potatoes in the cellar. We surrounded ourselves with our own produce and traditional processing and storage techniques. The availability of affordable refrigeration in the 1950s changed the whole culture of food supply and distribution in dramatic ways. Warehouse-sized coolrooms meant that fruit and vegetables could now be stored for months and sold out of season. Refrigerated trucks could transport milk and meat from outlying farm areas to distant cities. Large shop freezers could display frozen chicken, frozen vegetables and icecream — spawning the supermarket culture. As corporations bought up and amalgamated the smaller, family-owned farms, factories expanded and supermarkets offered consumers the price advantages arising from substantial economies of scale.

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By the late 1950s the Soviet Union and United States were engaged in their ‘space race’. As part of an all-encompassing program to ensure the success of their space missions, the Americans developed a program to minimise the chances of foodborne illness among astronauts. This included a ‘hazard analysis’ of all ingredients and processes, where critical operations were identified, monitored and verified. By 1971 the system was given the acronym HACCP, standing for Hazard Analysis Critical Control Points. It is a term the food industry still uses today. The HACCP system involves assessing all potential hazards (such as the types of bacteria which could contaminate milk during processing) and then identifying the ‘critical control points’ where contamination is most likely to occur. It is a kind of self-audit system where a food business — manufacturer, processor, retailer, restaurant and so on — could set itself up to be on the lookout for problems before they occur. For each risk an ‘acceptable limit’ is then determined. Exceed the upper limit — at which point the risk of contamination is deemed to be too high — and production must be stopped. Bacteria and other problem levels at the critical control points are monitored by management, with a system in place to institute corrective action when a problem is detected. In addition a record of inspections must be set up, maintained and checked regularly to ensure the whole process is working well. This procedure proved to be so successful that by 1974 a major food conference was devoted to the HACCP system, and a number of food companies had adopted it. In 1980, the World Health Organisation (WHO) got behind HACCP as a concept that could be applied in many countries outside of the United States, whether a developing or developed nation. By 1982 the WHO published a report which recommended the general application of the HACCP system by

the food industry everywhere. Today food producers in Australia generally have HACCP systems in place to minimise the risk of foodborne illness. In addition there are systems for certifying the effectiveness of a company’s HACCP program. Industries which, upon inspection, regularly and satisfactorily meet the HACCP requirements, may be accredited with what is called HACCP 9000 certification. This certification gives the business international recognition for its food safety assurance program. This makes it easier for the business to sell its food products in Australia and as exports to other countries. It is something which has become an important ingredient in international food trade, going on behind the scenes of your local shopping centre. Major supermarkets have begun to insist that their suppliers have HACCP systems in place within their own organisations. The food industry is placing an enormous reliance on HACCP: everyone has to get it right! Accreditation for HACCP involves management of all aspects of quality and safety during food manufacture and distribution, down to some very small details indeed: ¥ The warehouse must have an identifi-

cation tracking system to ensure that the first ingredients which come in must be the first ones to go out to customers. ¥ There must be a pest control program

with vermin baits clearly identified. ¥ The warehouse itself must be in good

repair so that flaking paint or bird droppings cannot get into materials. ¥ Food must be stored in a way that will

prevent cross-contamination or exposure to cleaning chemicals, rubbish, vermin or insects. Food-processing areas must meet similar stringent requirements. To achieve the high standards required by HACCP some companies have undertaken

A CLOTHES ENCO U N T E R major renovations and instituted policies affecting what staff wear and how they behave. Some examples include: ¥ the installation of bird wire to keep out

birds and eliminate droppings ¥ insect screens fitted to doorways and

windows ¥ special air circulation and dust extrac-

tion systems installed to ensure that the air circulating in food processing areas is fresh and clean ¥ staff required to wear special hygienic

uniforms and to use hair coverings (including beard masks) to reduce the risk of hair falling into product ¥ installing sanitising foot baths to ensure

that boots are clean before entering food production areas where the risk of microbial contamination is high ¥ installing special sanitising systems for

regularly cleaning all processing equipment daily, or more often, such as at the end of every production run ¥ introducing comprehensive training pro-

grams to ensure that all staff are familiar with procedures and practices ¥ not permitting staff who are ill with an

infection or have weeping sores to work on the premises. What are we to make of HACCP? It is a logical approach to targeting the risk areas of any type of business in the food industry, from the farm to the restaurant and corner store. But it is only as good as the effort that goes into it. Each business must ensure appropriate education in the issues of safe food; skills must remain up-to-date by constant contact with information sources; each business must think deeply about its risk areas and risk foods, analyse the situation and then draw up a reliable plan. On a daily, hourly, minute-by-minute basis the plan must be followed and the business must be prepared to incur economic loss by halting all work in the event of a problem.

When a problem surfaces in a modern f o o d - p rocessing plant the solution must really address the problem at a deep level. Sticking a memo up on the company notice board is rarely good enough. When one food-processing company found that pen lids were turning up in food mixing vats, all minds turned to fixing the problem. Supervisors, in part i cu l a r, still needed pens within the pro c e s sing area, so the company had to learn how to live with these ‘foreign objects’ in close proximity to the food. Knowing they could not remove the pens altogether, the eventual solution was to remove all pockets above waist height for anyone working near food p rocessing lines. If you had a pen you had to hold it in your hand or keep it in your pants: you could not stick it in your top pocket and lose it while bending over to inspect a vat of food. Some solutions, however clever, eventually betray their weaknesses. A problem does not necessarily re m a i n ‘solved’ in the food industry. In order to o v e rcome the problem of foreign objects i n t roduced to food areas by staff, many companies moved to ban conventional clothing — shirts, pants, skirts, dresses — or at least to comprehensively cover the clothes with one-piece overalls. The overalls would become a barrier between the employee and the food, and could be simply dropped off for cleaning at the factory door. Some time later a wrinkle emerged. It became apparent that when staff went to the toilet they dropped their overalls to the floor so as to reach and unfasten the underlying clothes or underw e a r. Of course the overalls were then absolutely contaminated. At least with pants you were n ’t risking contamination of clothing on the upper body.

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There are concerns that some small businesses lack the resources and skills to take on such a draining and expensive task. Fortunately there is some government assistance. But mistakes can happen, and potentially dangerous food can slip through, when someone fails to monitor the situation closely, or even because management failed to analyse the risks fully. If, in your company’s HACCP plans, you are not looking for a particular risk — a certain bacteria or virus, for example — you will not detect its presence. HACCP is not a mantra for infallibility.

DETECTING THE FOREIGN LEGION Many companies have metal detectors installed on food production lines and require that all cuts and wounds be covered with w at e rp roof blue Band-Aids containing a metal thread. Even disposable hearing protection must contain a metal thread. Special metal pens are also used, as plastic pens might not be detected should they accidentally fall into the food. When the metal detector is activated, food products are automatically diverted from the main production line to a separate bin. In some factories an alarm rings to alert a supervisor and the cause of the problem must then be investigated and corrected. This sort of accident is treated very seriously by leading food companies. Some companies even have special cleanup procedures should any glass be found anywhere on their premises. A case in point concerned an incident where glass from a car’s broken headlight lens made its way from the staff carpark into the factory, stuck into the heel of a person’s shoe. For similar reasons, animal manure or animal by-products are not used as fertilisers on gardens or lawns outside the food factory or warehouse. Another common rule is that staff must eat only in designated areas. No food can be taken into production areas. Smoking is prohibited. Nail polish, false fingernails and

false eyelashes, jewellery, watches, hair bands, or clips or rings other than a plain wedding band must not be worn. Only clean companyissue uniforms are worn, and staff are instructed that hands must be washed after any activity which may introduce contamination: after eating or going to the toilet; after touching hair, nose, mouth, eyes, or blocking a sneeze; and before entering any food production areas.

TESTING AND COMPLAINTS Generally speaking, all complaints about food products produced by large companies are taken seriously and investigated thoroughly to protect their image among their customers. Testing for food-poisoning bacteria is standard procedure in companies producing ‘risky’ foods. The frequency of testing is determined on the basis of statistical analysis of the information known about safety of the product. Should a sample be found to give a positive result, the entire batch or production run is put on hold while further testing is carried out.

YOUR GLASS OR MINE? A consumer, sitting down to a meal, found a sliver of glass in the food. He complained to the manufacture r, which in turn asked for the glass fragment to be sent to their laboratory. There it was analysed, to reveal the precise type of glass that had made its way into the food, so the problem could be traced. Was it from a broken light in the factory, f rom a window, or from part of the p rocessing machinery ? The glass turned out to be from none of the sources in the factory, but from a wine glass. Lo and behold, the consumer had been drinking wine with his meal. Case solved!

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It sometimes happens that checking reveals that the test gave a false ‘positive’ result. In this case, if subsequent testing reveals no significant levels of organisms, the product on ‘hold’ is released for sale again. If, however, subsequent testing confirms unsafe levels of micro-organisms, then a more extensive testing program is carried out. All contaminated product is safely disposed of and further production halted until the source of contamination is traced and eliminated. These situations also require extensive sanitation or cleaning of the plant. The machines stop moving and the cleaners start scrubbing. This can go on for hours or even days. These procedures greatly reduce the chance of any contaminated food reaching the supermarket. Although major food companies regularly test the products at risk for food-poisoning bacteria, testing alone will not necessarily prevent an outbreak, for the simple reason that it is not practical to test every packet or jar of food produced. Furthermore some types of food-poisoning bacteria, such as certain strains of Salmonella, are so potent that it only requires a few organisms per serving to cause illness. Such low levels of contamination, which may be randomly distributed through a product, are difficult to detect and most likely would not be picked up by standard testing procedures. It seems the only way this sort of outbreak can be prevented is to have very strict hygiene procedures during processing, handling and storage. Recent cases of product failure have provided important lessons to food producers and focused attention on the need for not only adequate food safety testing programs but also regular auditing of the food processing chain. This aspect is now emphasised by the large supermarket stores in many countries, particularly for high-risk foods such as fresh fruit and vegetables, chilled and frozen foods. A number of supermarkets have also introduced HACCP systems as a way of ensuring that freezer and cool-room temperatures are regularly checked, and thermome-

ters calibrated against certified national standards. Salad bars must be constantly supervised so that any contaminated product is immediately disposed of. Large companies are obviously in a better position to allocate resources for training staff, auditing food hygiene and storage conditions and upgrading facilities to meet HACCP protocols. But what about small businesses — the local takeaway, restaurant or bakery? At the present time, at least in New South Wales, Queensland and South Australia, a person or company can open up a

MICE CRAC K E R S Food processing plants have metal detectors and all sorts of other devices and techniques designed to keep foreign objects out of the assembly line. However, sometimes nature finds a way past the barriers. In Australia, a consumer got more than he bargained for when he opened his packet of biscuits only to discover one ‘biscuit’ was in fact an almost intact mouse. The mouse had somehow evaded security, winding up in the ingredients. From there it made it to the mixing vat, where it was cooked and dehydrated. On, then, to the ‘pre-former’ which gave a basic shape to the dough, before squeezing under the roller. Now, laid flat, the mouse was conveyed to the cutter. By a stroke of considerable luck, the cutter came down centred on the mouse, resulting in a somewhat mouse-shaped biscuit. From there it was a quick trip through the oven to the packing area and into the carton. After all, he had the right shape for it. Fortunately the consumer stopped short before sinking his teeth into the mousecracker. The biscuit manufacturer received a most unwelcome correspondence from the consumer, who was pacified some time later, it is believed, by a handsome supply of brand new biscuits. None of these, however, was quite as feral.

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small food business without any previous training or experience in food hygiene or food safety. Furthermore, no compulsory training is required subsequently, although courses are offered by Technical and Further Education and seminars on safe food handling are regularly run by local councils. The coming of national regulations should cover this gap. The food-processing industry in Australia and New Zealand is seen as very safe. In part this is due to a high level of automation. According to the ANZFA, only an estimated 4 per cent of cases of foodborne illness in Australia is the fault of the food processing industry. Something is going right. However, nearly 75 per cent of foodborne illness is the result of action and inaction from retailers, the transport industry, and all those involved in food handling. There are still a lot of problem areas which need improving. ANZFA plans to introduce new regulations for tighter control over food premises. One of the proposed changes is to require that at least one person in any food business or food outlet — even small ones — has received appropriate, recognised training in food safety and handling. Prior to these new regulations, our food safety is patrolled by government food inspectors in each state who carried out random inspections of food premises. In the case of small businesses, a complaint to the health department about something like a cockroach in a bun would result in an immediate inspection of the premises. If no cockroach infestation was found the problem would be discussed with the proprietor and advice given on appropriate insect and vermin control. On the other hand, where a cockroach infestation was found the owners would be given a warning and required to eliminate the problem. This would be followed by a subsequent inspection. Repeated offences, and evidence of negligence, could see the owners hauled before a court and fined. In food businesses, health department inspectors play both an auditing and advisory

role. They look for potential hazards too — such as a tub of mince stored under a fluorescent light, which could potentially contaminate the mince if the tube broke into pieces. Imported foods are checked for safety by the Australian Quarantine and Inspection Service. Some large international supermarket chains now only import food from factories which have been inspected by their own staff and which are seen to meet international food standards. These foods are then further subject to periodic testing by laboratories with national accreditation — for example, you might see the ‘NATA’ symbol displayed at the premises, indicating they are accredited by the prestigious National Association of Testing Authorities. As more and more consumers move from home-prepared food to processed foods and pre-prepared meals, regulatory authorities are moving towards closing the risky gaps in the food-processing chain. But everyone has a responsibility. Managers and employees in the food industry are now required to ensure, as an individual responsibility, that the safety procedures are followed to the letter. Staff in shops and supermarkets must ensure that food is stored correctly and in such a way that it cannot be contaminated. We, the consumers, must take responsibility for what happens after we purchase the food (see especially Chapter 17). A food manufacturer who has paid out millions of dollars to ensure safe manufacturing procedures and well-trained staff, or a supermarket which has done likewise, loses control of the product at point of sale to the customer.

NEW TECHNOLOGIES TO THE RESCUE Traditionally, when looking for the bacteria or a problem in the processing factory behind an outbreak of food poisoning, scientists have relied on techniques which take a sample of the food to the laboratory where they seek to

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isolate the suspect cells, grow them and see if they can be identified. This can be very time consuming. Indeed, in many instances the victim will have recovered before the pathology report is ready! It can be a case of time and money poorly spent. One of the newer techniques goes straight to the heart of the bacteria or microbe: its DNA. By identifying the gene sequence it is possible to know quickly what pathogen caused an outbreak. A technique called ‘polymerase chain reaction’ lets scientists make an exact match of the genetic sequences of those micro-organisms under investigation. Accuracy and speed are what we gain.

¥

Irradiation

Food irradiation is another tool of the scientists in the hunt for safer food. ‘Irradiation’ is the process of applying a measured dose of radiation to something — in this case, to food. Typically, this involves passing food rapidly through a radiation field produced from gamma rays of cobalt-60. Applied to food, it has always been a matter of controversy. The great benefit is said to be the ability of radiation to kill living things in the food, including bacteria (importantly Campylobacter and Salmonella) parasites and insects. It is also argued that the process can slow the natural spoiling of the food and, in some fruit and vegetables, delay ripening. It does not end up making the food radioactive, and it seems that the nutritional value of the food is not significantly diminished by the radiation. A further benefit is that irradiation replaces other protective processes — such as chemical fumigation — which also cause consumers a degree of consternation. On the other side of the fence is the concern that we do not know everything that might be going on inside the food when irradiated, and secondly, there is always the chance that the process might be applied wrongly. Radiation does change the food it bombards, creating what are known as ‘radiolytic products’. Similar breakdown

products, however, are also produced by ordinary cooking processes. Historically, food irradiation first raised its head back in the 1930s. Little was done about it until World War II when the military was looking for ways to keep army rations fresh and safe in the field where there was no refrigeration. Research finally took off in the United States in the 1950s. The first food products approved for irradiation in the United States were wheat and wheat flour. The year was 1963. Irradiated foods are now found in the United States, China, former Soviet nations, Belgium, France, Japan, India, Israel … the list goes on. In 1997, Hudson Foods Inc, a company based in Arkansas, found that E. coli O157: H7 had contaminated its hamburger mince. It was decided that the product must be withdrawn from sale. However, this was to be no ordinary product recall. In all, Hudson Foods recalled a little over 11 million kilograms (approximately 25 million pounds) of hamburger suspected of being contaminated with this type of E. coli, making this, at the time, the largest recall of meat products in the history of the United States food industry. Later that year, in December 1997, the US Food and Drug Administration approved the use of radiation to control E. coli O157: H7 in red meat products. In part this move was brought about because of a number of crises involving hamburger mince (ground beef) — a staple part of the American diet. In the United States there is a requirement that irradiated foods carry a label which identifies that this controversial process has been applied. The label should say ‘treated by irradiation’ or ‘treated with radiation’. However, if a product uses spices or seasonings, for example, which have been irradiated, the final product need not make this disclosure. Neither is there an obligation in law on American restaurants to notify their customers that irradiated foods are being served. It is a very patchy performance by the industry and its regulators, although it is easy

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to understand how difficult it would be to know the history of all raw ingredients. Several leading organisations — including the US Food and Drug Administration and the WHO — support the proper use of radiation for food safety. Others, including many consumer organisations, remain opposed.

NEW HOPES, NEW PROBLEMS Science is rarely neutral once it is out in the marketplace. Pesticides, for example, deliver better looking fruits and vegetables, but they can also make us sick when we eat them. It is a situation which brings to mind the poisoned apple offered to Snow White: beautiful to look at, tasty to bite into, but containing a poison. In November 1996, at the World Food Summit, the WHO estimated that pesticides caused three million cases of severe food poisoning and 220,000 deaths around the world each year. Increased cancer risks are still being investigated. Technology is not always a pure solution. But technology holds the hopes of the world for an increased and a safer food supply. Inventors are constantly coming up with new products of interest to the food industry. Here are a few which are in development or, in some advanced corporations, have already been implemented: ¥ Computerised sinks. When a worker

fails to wash his or her hands, the computer notifies the manager. ¥ Hand-held digital thermometers.

Accurate and fast, these thermometers allow staff to check food on the production line quickly. They can even generate a print-out so you can review or look for undesirable patterns and trends. ¥ Computerised, digital temperature

recording built into fridges, freezers, broilers and heated display cabinets. All stages of storage and cooking in a

food-processing plant or restaurant can now be monitored by computer. Temperatures will be recorded constantly, giving management early warning when food is straying out of safe temperature ranges. Head office, no matter how remote geographically, can know what is going on at its restaurants and fast-food outlets across the nation. ¥ Hand sanitisers which do not rely on

messy soap and water. ¥ The use of video cameras to check how

well a worker has washed his or her hands. A blue- or green-coloured soap will be detected by the video camera which then digitises the image and undertakes a pixel-by-pixel search for areas of skin which have not been ‘soaped’. A software program will determine if the area of unsoaped skin exceeds guidelines, and, if so, an alarm will sound. Then it is back to the sink. ¥ According to New Scientist magazine,

researchers at Matsushita Electric in Osaka, Japan, have developed an experimental kitchen appliance capable of testing food for the presence of food-poisoning bacteria such as Salmonella and E. coli O157. You take a portion of the food, turn it into a solution and pour it into a tank. Electrically charged bacteria pass across a membrane into a second tank where their concentration increases and they are highlighted with a dye-labelled antibody. A video camera detects clumps of the dyed bacteria, sending images to a computer installed with optical recognition software. The device, which is about the size of three blenders in a row, could sell for less than A$2000. So, someone is watching over us. From the farmer to the truck driver, the government food inspector and the person who designs the refrigerators of the future, thou-

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sands of people are working to deliver safe food. In a developed nation, the system works well. But no matter how good the system there will always be occasional failures — and we are continuing to find and fix problems with current ‘solutions’. It is not a static process. Do not be put off pursuing a food manufacturer, supermarket or restaurant from which you believe you purchased dodgy food. Chase the matter all the way, if you feel so inclined, until you get a satisfactory answer.

The best food companies will want to hear your complaint. After all, you might be sounding the first warning of what could otherwise, without quick remedial action, lead to a costly food safety recall campaign and millions of dollars worth of bad publicity. Many companies are interested not only in information about illness, but any feedback on the quality and condition of the product when you bought it. That is how they weed out the slack shop manager or careless process-line supervisor.

SUMMARY ¥ Major food industry companies spend millions of dollars on equipment, training and pro-

cedures to provide a safe food supply. ¥ New technologies and new procedures may improve the overall level of safety, but they

can also introduce new health concerns. ¥ Consumers have an important role to play in this process of gradual improvement. The

food industry needs our feedback. ¥ Some elements of the industry are quick to blame the householder when a case of food

poisoning appears. But they can be wrong. Do not be afraid to insist that the food company concerned, or that government health inspectors, investigate your complaint.

CHAPTER

20

FUTURE UNCERTAIN

ARE THE RISKS INCREASING OR DECREASING? According to New Scientist of January 1998: ‘The total incidence of food poisoning is seven times as high as 15 years ago’. Is this alarmist reporting? A search of various research reports and public statements from significant sources adds weight to the claim of a general trend upwards, and the level of ongoing concern. For example, figures from Scotland show food poisoning notifications increased by more than 25 per cent in the year from 1993 to 1994. According to a 1998 statement from the Office of the Veterinary Officer of Australia, many European countries have identified an increase in reported cases of foodborne illness since the middle 1980s. In Australia there have been increases and decreases. Annual notification of illnesses for Salmonella and Campylobacter, for example, are on the way up; some remain fairly steady (example, listeriosis); while others,

such as typhoid, are decreasing in incidence. An investigation of reported outbreaks of foodborne disease in Australia from 1980 to 1995, published in the Medical Journal of Au st r al i a, (‘Foodborne disease: current trends and future surveillance needs in Australia’, by Scott Crerar, Craig B Dalton and others), identified 23 outbreaks in the first nine years, and 105 in the last seven years of the study. It certainly seems that more outbreaks are being reported across the globe. In the end, however, the statistics perhaps do a disservice because they are not based on how many people get sick, but on how many cases get reported to hospitals and doctors. Most cases of food poisoning go unreported. Surveillance authorities in the United States have been shown to pick up less than 1 per cent of cases of salmonellosis during an outbreak. How many of us rush off to the doctor when all we experience is a dose of diarrhoea? The Australian Food and Grocery Council put it like this:

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through the mucus lining of intestines; be able to sense locations suitable for survival and growth (have ‘chemotaxis’proteins); be able to adhere to the lining of intestines (have adhesion proteins); produce toxins or have invasion genes; and produce iron-binding chemicals to utilise the iron which is otherwise bound in Health surveillance authorities are now on haemoglobin. For example, a bacterium may have all the the lookout for more problem pathogens than a b ove characteristics except that it cannot surever before, and that, too, swells the numbers vive the pH of the stomach. This bacteria of reports. Increased awareness of, and testing would be harmless (except perhaps for the for, Campylobacter bacteria is just one instance elderly or people on antacid medications). of this. H ow ev e r, if one of these bacteria acquires Perhaps such estimates are, in the end, of genetic info rm ation from another bacteria little value to us. But what we do know is this: new, dangerous micro-organisms keep moving which has no toxin-producing genes but is acid to centre stage. Twenty or thirty years ago tolerant, it now has the necessary requiremany of the food-poisoning bacteria that we ments to survive the acid conditions of the now acknowledge — Listeria monocytogenes, stomach. If this new bacterium has the opporCampylobacter jejuni, Vibrio parahaemolyticus, tunity to grow and establish itself a new pathCyclospora cayetanensis, E. coli O157: H7 and ogenic bacterium will have entered the related E. coli, some types of Salmonella, Vibrio environment. How bacteria exchange genetic informacholerae 135, Vibrio vulnificus, andYersinia ente tion has only been understood by scientists relrocolitica — were unknown or relatively atively recently. Bacteria can contain genetic insignificant. i n fo rm ation in various parts of the cell including These new microbial threats have not the chro m o s ome, the ‘plasmid’ and on virus-like spontaneously emerged, but have resulted p roteins called ‘phages’, which can infect a cell from a series of events or episodes associated by attaching to the outside. They then inject with the transfer of genetic information their genetic material into the cell. Phages carry between bacteria; new developments in food the pathogenicity genes for several common production and processing methods; changes food-poisoning bacteria including Staphylo in food distribution and preparation practices; coccus aureus, Vibrio chol era and Clostridium as well as globalisation of the food industry and b o t u l i nu m. In the case of C l o stridium botulinum, other recent socio-economic trends. a phage carries the gene for the extremely It seems that somehow, with our modern food production and marketing methods, we potent botulinum toxin. Because phages can have created an environment which has facili- fairly readily transfer genes within a genus, it tated the survival and spread of these previ- has been discovered that several Clostridium ously harmless organisms which have acquired species now have the genetic information on new genetic information equipping them now phages to produce the botulinum toxin, where previously they were relatively harmless. to cause poisoning. Plasmids are also readily exchanged To understand how this occurs we need to consider the function of some of the genetic between bacteria, and carry genes for producmaterial found in bacteria. For a bacterium to ing toxins, for example in Shigella species, and be capable of causing poisoning in humans, it Vibrio parahaemolyticus, which is one of the generally has to be able to survive the low commonest causes of food poisoning in Japan. Parts of the cell chromosome, called ‘PAIS’ pH of the stomach; have ‘flagella’ to propel it Although there is a widespread commitment to the provision of safe food to the community, accurate statistics concerning the incidence of foodborne diseases or food poisoning are unavailable in this country. The very incomplete data we do have seems to suggest that the incidence of food poisoning is increasing and this is cause for concern.

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(pathogenicity islands) and ‘transposons’ can also transfer genetic material associated with disease between bacteria. These are responsible for carrying, for example, the invasion and survival genes in Salmonella species, and virulence regulation and cell-to-cell spread in Listeria monocytogenes. Changes in processing conditions can also increase the pathogenicity of bacteria. For example, food technologists and health authorities have introduced lower pH (more acidic) conditions in some manufacturing and packaging processes in an effort to make the products safer. However, it has now been discovered that low pH conditions can turn on ‘survival’or ‘SOS’ genes which not only induce survival at low pH but can activate other genes that cause illness. Furthermore it appears that bacteria grown in low pH conditions can produce signals that induce acid tolerance in bacteria not directly exposed to low pH. By producing foods under these conditions we also kill off many harmless competing bacteria, and other bacteria which normally would not survive our stomach acids. By these processes we are in fact selecting for potential harmful bacteria which will survive one of our body’s main defence mechanisms against food poisoning: the acid in our stomachs. We have also become more aware of the disease potential of common micro-organisms. For many years E. coli was seen as nothing more than an indicator of poor food handling processes — after all, it was a major component of the bacteria found in the digestive tracts of animals and humans. It wasn’t seen as bad in itself. Now we know certain strains of E. coli can be lethal. Half of the cases of Salmonella in the United States involve a type of Salmonella enteritidis (phage type 4) barely known until as recently as the early 1980s. Reported cases of E. coli O157: H7 infection world-wide have increased by around 180 per cent over recent years, decreasing a little in 1997 before returning to their climb in 1998. In the United States, too, the statistics can move about wildly: between 1996 and 1998 Salmon -

ella enteritidis infections decreased by 44 per cent, and Campylobacter infections declined by 14 per cent. The reasons for these falls are not fully understood. One of the scariest of the newer illnesses is haemolytic uraemic syndrome, first reported around 45 years ago. This illness is caused by some of the rarer types of E. coli (O157: H7 and O111) — detected only from 1982 onwards in North America, Europe and Australia. One of these, E. coli O157: H7, was implicated in the major outbreak of 1992–93 involving contaminated hamburgers from the same chain of restaurants across four US states: 580 people were affected, having eaten one of the hamburgers or having been in close contact with someone who had. In the end 171 people required hospitalisation, 41 developed haemolytic uraemic syndrome, and four children died. The impact of these infections is astonishing. One child died following a seizure and cardio-respiratory arrest; other infected children experienced kidney failure, pancreatitis, glucose intolerance, cardiovascular or pulmonary complications, neurological complications and more; many of the victims required dialysis or blood transfusion. Another shocking revelation is that many of these illnesses hit children hardest. The median age of those affected by this hamburger outbreak was five, with the age range going from 1 to 15 years. As noted earlier (Chapter 5), the 1994 outbreak of E. coli O111 from fermented mettwurst in South Australia had devastating effects on young children (median age of only four years) while adults were mostly unharmed. E. coli is not the only emerging threat. Salmonella bacteria have been known for a long time, but an emerging strain — Salmonella typhimurium DT104 — is catching the attention of health officials. In Britain, for example, while the overall incidence of salmonellosis has been constant during the 1990s, there has been a marked increase in the DT104 strain. In 1991 it accounted for about 500 reported cases out of roughly 30,000 cases of salmonellosis, but five

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en meat should always be cooked thoroughly. Many of the large-scale outbreaks of E. coli O157: H7 in the United States have involved undercooked hamburger mince. Australia has yet to achieve the reliance on the takeaway hamburger which plagues the United States (where an ordinary sandwich sells for US$4 while you can have a burger for just 49 cents). Since ‘mad cow disease’ (bovine spongiform encephalopathy) struck Britain, there has We must anticipate that it may become more been fear of animal diseases passing to humans. widespread in the environment and hence In late 1997 more than 1.4 million chickens and throughout the food chain. We must regard it other fowl were slaughtered in Hong Kong to as an ‘emerging’ pathogen and monitor the contain the spread of bird flu virus, which could situation accordingly. spread to humans: four people died and 16 were And for good reason. Salmonella typhimuri - admitted to hospital. The chicken population um DT104 in not just any old type of paid a higher price. In 1997, in a desperate attempt to prevent Salmonella. It can infect animals — particularly cattle, but now also pigs, sheep and poultry — the spread of mad cow disease to humans, the without them showing any signs of illness. It is British Government banned the sale of all beef resistant to many commonly used antibiotics, ‘on the bone’ in butchers’shops, supermarkets including ampicillin, chloramphenicol, strepto- and restaurants. Here are three more examples of the mycin, sulphonamides and tetracyclines, and breaking wave of new or emerging microquinolone antibiotics. This resistance to antibio rg a n i s m s : otics owes much to the widespread use of antibiotics on farms and for people. Fortunately ¥ In early 1997 an outbreak of hepatitis A there are still some antibiotics in the medicine occurred, linked with oysters from Wallis chest which are effective against this nasty Lake. It is believed this was the first time strain of Salmonella, but the choices are more in Australia that people picked up this limited than we would like. virus from oysters. Australia’s geographical and cultural ¥ Hepatitis E has become the most freremoteness from the northern hemisphere still quent cause of hepatitis in Asia and must gives the nation a measure of protection. So, for n ow be considered as an emerging threat example, while Salmonella infections are a in Australia, where it is uncommon. major problem in the United States and Europe — due mostly to Salmonella enteritidis which ¥ In the 1990s there have been a number can cross from chicken meat to eggs and egg of outbreaks of illness in the United States products — this type of Salmonella is not a big and Canada related to the protozoan problem in Australian chicken flocks, and so we parasite Cyclospora cayatenensis (affecting are spared (for the time being). Here the most foods like fresh strawberries, fresh raspcommon strain of Salmonella in chicken meat is berries, drinking water and fresh basil/ Salmonella sofia — one that is thought not to be pesto sauce). It produces a flu-like illness pathogenic to humans. (New human problems with prolonged or relapsing diarrhoea. can emerge from the animals we breed for food.) In the United States, it has gained much So while it is true that chicken is safer in media coverage, leading to a multi-millionAustralia than in many parts of the world, this is dollar collapse, at the time, of sales of no reason for carelessness in preparation: chickCalifornian strawberries.

years later reported cases had jumped to 4006. Over a similar period in the United States there was evidence of a sharp increase in this strain. In the United States more than one-third of those who became sick with this strain of Salmonella required hospitalisation and three per cent died — very unusual for Salmonella. In 1998 the British Institute of Food Science and Technology said:

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¥ In 1995 cases of Cyclospora cayatenensis

were reported in refugees staying in Tasmania. This bacteria, which was first described in Nepal in 1970, is now commonly found in many parts of the world in areas of poor sanitation and hygiene. Scientists are more aware than ever before about what is going on in different parts of the world and what might be just around the corner for us all.

GETTING AROUND AND BECOMING KNOWN How do ‘unknown’ bacteria and viruses make their way from one small corner of the world into our own backyards? Scientist Karl Bettelheim offers this scenario: A person carrying the strain of E. coli visits another city. When he goes to the toilet his faeces enters the sewage system which might then be discharged into a river, lake or the ocean without complete treatment. Fish get contaminated; sea birds eat the fish; the birds defecate over the land where sheep and cattle graze … and it enters our food supply. Far fetched? A 1997 study of 700 samples of fresh gull faeces collected from beaches in Britain found that 3 per cent contained E. coli O157. Our civilisation does much to hasten the i n t e rn ational spread of micro-organisms, including: ¥ pumping sewage into rivers, lakes and

via ocean outlets near beaches ¥ dumping sewage from boats and trains ¥ off-loading sewage from the airplanes of

one country when they arrive in another. According to a 1997 report of a study carried out by the University of North Carolina, 19 out of 40 samples of sewage pumped from international flights arriving in the United States contained infectious viruses which had survived the trip despite the presence of disinfecting chemicals in the planes’ sewage systems.

Bettelheim said, in 1996: ‘Unless major changes in the whole food chain are instituted it is unlikely that the problem of EHEC [enterohaemorrhagic E. coli — one of the newer nasty ones] may get worse before one can see any improvements’. That is because standard tests in food for E. coli fail to detect all the EHEC strains. Cattle and other animals infected with these bugs are rarely ill, so it goes undetected there too. We also promote our own vulnerability to large-scale outbreaks of foodborne illness by gathering closer and closer together in huge cities, often scarred by great areas of stifling poverty where medical care is unaffordable; vast numbers of people now travel the world, for business or adventure, and bring home more than just a few snapshots and a bottle of duty-free perfume. For micro-organisms it is now a global picnic.

ARE WE OVERLY DEPENDENT ON ANTIBIOTICS? Two things of concern are happening here. Firstly, farmers in various parts of the world have been using antibiotics on their animals to control disease. As bacteria multiply rapidly, relatively large numbers of mutant bacteria are also being produced in a short period of time. Some of these bacteria will have a mutation which makes them resistant to certain antibiotics. As a result we now have an increasing number of antibiotic-resistant bacteria in the environment. When these bacteria infect humans they cannot be controlled successfully with standard antibiotics, and new or different antibiotics must be brought in by the doctors. For this reason the antibiotics used in animals for food production must not be the same as those used to treat disease in humans. In some countries, the use of antibiotics on certain meat-producing animals has been banned. Even so, the number of effective antibiotics

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available to treat human illness is diminishing. We can play a role in combating this serious problem by calling on government to make progress on ensuring animals used for food production live healthy lives — reducing overcrowding and ensuring they have access to clean air, water and wholesome food. The second threat to our reliance on antibiotics comes from genetic engineering of food. At an international level, government agencies have expressed concerns that antibiotic-resistant genes are being used in the development of new crops. Once these crops move into production, there will be a massive increase in the exposure of these genes to all sorts of microorganisms. At this level there is the danger that micro-organisms will acquire some level of resistance to these antibiotics. While government agencies might express concern about genetic modification of foods, will this influence those corporations rushing to develop (and own the rights to) valuable new crops? The laws in one country might stop unwise research and development, but there is always another country without restrictions. And once the crop has become a sack of grain it can travel the world.

CHANGING OUR PREFERENCES Throughout the developed world there is a substantial consumer push for more natural foods. Although experts might want to debate what consumers mean by ‘natural’, these factors seem relevant: ¥ no artificial preservatives ¥ no artificial additives ¥ low in sugar ¥ low in salt ¥ low in fat ¥ minimal processing ¥ not undergoing certain controversial

types of processing, including irradiation and genetic transformation ¥ less packaging ¥ ‘healthy’image and marketing.

Some manufacturers have responded to the perceived challenge of the future by producing standard food items which address some of these criteria. For example, there is tomato sauce (ketchup) with reduced salt; there are biscuits packed in a single bag instead of within a plastic bubble tray inside a bag. In many cases there is simply a trade-off: an improvement in one way, but at the expense of another. For example, when sugar is removed from soft drinks we see artificial additives like aspartame take its place. From a food safety perspective, however, the issue is different. Take the example of ordinary jam. Jam relies on three main factors which make it a safer food: high fruit acid, lots of sugar, and cooking. The result is a food product which we can leave open for weeks or months, which we might not even keep in the refrigerator, yet which remains safe and convenient for months. But what happens when a manufacturer pulls out much of the sugar? Fortunately the jam can still be safe because it has multiple safety factors to fall back on. But what if we start to say we don’t want the jam to be cooked or heat treated? Gradually we edge our way closer to a situation of risk. At the very least we might create a jam with a reduced shelf-life, or which must be kept refrigerated. Food processing companies are researching alternatives which will still guarantee safe food. We have already mentioned some of these techniques — such as irradiation — but others are less well known, including the used of a pulsed electric field or a bright light. Pressure, at a level thousands of times the pressure in the Earth’s atmosphere, can actually pasteurise food without heating it. Sadly it is often the case with such techniques that they only kill the pathogens and enzymes on or near the surface

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of the food, without going as deeply as traditional cooking and processing can reach. Some techniques are used in place of preservatives, because additives must be listed on the food packaging, but the techniques need not be revealed. For example, gas mixtures are used on certain fruits to delay their ripening, thereby giving a longer shelf-life and allowing increased transport times. But consumers often complain that the fruit they buy is not ripe or ready to eat. In many cases it can look great on the outside — thanks to waxing of apples, for example — but be rotten inside.

Tauxe put it in Emerging Foodborne Diseases: An Evolving Public Health Challenge, (Centers for Disease Control & Prevention, Atlanta, Georgia):

Behavioural trends are also cause for concern:

Processing by salt, sugar and cooking are traditional, successful methods of providing safe food, but are subject to fashion. Are we witnessing a shift away from multiple levels of safety to minimum safety? There are concerning trends also in the way we manage our crops and livestock and how we process foods:

¥ In western nations there is a shift

towards eating outside the home, or in having meals home delivered. In part this is due to the family situation where the parents, whether two or one, work in outside, paid jobs. There is little time or energy for meal preparation and cleaning up. The result is often that we eat highly processed foods such as pizza, hamburgers or fried chicken which have been stored and then transported in less than ideal conditions. Control has gone out of the household kitchen.

The foods contaminated with emerging pathogens usually look, smell, and taste normal, and the pathogen often survives traditional preparation techniques: E. coli O157: H7 in meat can survive the gentle heating that a rare hamburger gets; Salmonella enter itidis in eggs survives in an omelette; and Norwalk virus in oysters survives gentle steaming. Following standard and traditional recipes can cause illness and outbreaks.

¥ Farming has become more intense:

more crops, more frequently, more produce, everything closer together. ¥ Local small abattoirs and markets have

given way to larger, centralised abattoirs and markets. This means animals from different parts of the country mix together, get smeared with bacteria from skin, hair and faeces, and pass any infections around.

¥ There has been the introduction of ready-to-eat products in supermarkets, chilled not frozen. These have a shorter shelf-life than frozen meals and must be eaten within a few days of purchase. Some experts trace the emergence of Listeria monocytogenes as a major foodborne pathogen to the increased use of cold storage as a long-term strategy for keeping food. (Listeria monocytogenes can continue to grow at refrigerator temperatures.)

¥ Organic farming is increasing in popu-

¥ The population is aging, and as a result

¥ New packaging systems are being

immunity might be decreasing. This means the community, as a whole, is becoming less able to handle the tough pathogens.

larity (although this might actually turn out to be a benefit here). ¥ Hydroponics and aquaculture are also

on the rise. used. ¥ Perishable foods have become a

commodity traded internationally. ¥ Gene technology, affecting the growth

The ‘old ways’ might not be good enough any longer to keep us healthy. As Robert V.

and transport of foods, is being introduced.

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All of this means growers, manufacturers and food processors are listening to what the consumer wants, and are trying to create and deliver it. Many of the changes appear to solve problems or create improved foods (although many people would debate this). However, wherever there is change, there is the risk of unforeseen outcomes. When so much is new, who is looking out for the unforeseen? How long will it take us, the consumers, to learn how to handle the foods we grew up with in new ways? We can expect mistakes to occur at every level, from the farm to the factory, to the home and cafe.

THE GENE ARMOURY Will the genetic engineering revolution save us from foodborne illness? Genetically modified foods are currently being produced and sold in many parts of the world. In Australia, up until May 1999 health officials had received applications to approve 20 genetically modified foods, including herbicide-resistant soy beans, canola, corn, sugarbeet and cotton, and insect-resistant cotton, corn and potatoes.

Genetic engineering involves selecting genes from one living source and placing them into the structure of another, thereby hoping to pass a desirable attribute or cure a fault. Examples include: ¥ soy bean crops which are resistant to a

widely used herbicide. This means the farmer can spray the crop, kill the weeds, but leave the crop alone ¥ tomatoes which are designed to sur-

vive transport better (ripening and softening are delayed) ¥ potatoes which resist attacks by certain

insects ¥ a virus-resistant squash ¥ a rice crop, developed by the Chinese,

which contains its own insecticide. At present the use of genetic engineering techniques are focussed on issues like better crop control and food processing: not food poisoning. That may change. One day we might see chickens born with resistance to certain Salmonella bacteria.

THE BATTLE FOR FOOD SAFETY N EW RISKS emerging dangerous micro-organisms aging population is more vulnerable changing consumer preferences (more ‘natural’,less processing, etc.) pollution is increasing world-wide genetic manipulation of food antibiotics resistance international travel and trade new micro-organisms in town water supplies large batches mean large numbers of consumers are affected when safety procedures fail not passing on the traditional skills of running a home kitchen

N E W O P P O RT U N I T I E S better recording of statistics improving government regulations big companies can afford safer systems improved transport and storage some action to reduce pollution emphasis on training food handlers science delivers new tools

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For the moment there seems to be little scientific evidence to support the idea that genetic manipulation of foods will harm humans. There have been precautionary measures taken, however, over the use of genes from common allergens (like the peanut) in other foods. The only proof will come many years from now.

A ROLE FOR GOVERNMENT The task of keeping a nation’s food supply safe and reliable has reached monumental proportions. In the United States no less a person than the president heads the push to maintain safe food. It is seen as that important in America. In Australia, however, it doggedly remains a state-by-state issue. Recent moves to harmonise the regulation of the food industry in Australia and New Zealand have raised their own set of problems. The aim of these moves is to reduce the regulatory burden on the food sector but, at the same time, to provide a safe food supply. At the time of writing, the Australian Government is considering shifting the con-

trol and supervision of the food industry from health departments to agriculture departments. Agriculture departments have a major role in promoting exports and the image of healthy crops and livestock. Clearly there is a fundamental conflict of interests between protecting the industry from scandal, and informing the public of potential food poisoning and contamination outbreaks. There are also pressures on the resources of food inspectors and quarantine inspection s e rv i c e s. Communication difficulties arise from poor English language skills in parts of the food preparation and restaurant industries. Government regulators want to place more responsibility onto the shoulders of individual food businesses, emphasising a style of self-auditing and implementation of HACCP methodologies. In August 1999 the Australian government bowed to consumer pressure by creating the office of Gene Technoloy Regulator. The Regulator will have the power to stop research activities which raise public health concerns. Food is one of those areas where consumers need greater involvement from government, not less.

SUMMARY ¥ Because the figures are ‘rubbery’ and hard to obtain, it is difficult to confidently say that

the prevalence of food poisoning is improving or becoming worse. ¥ However, some newer, dangerous bacteria and viruses are emerging into prominence.

Some of these do a lot more damage to our bodies than nausea, diarrhoea and abdominal cramp. They can harm our liver, make us diabetic, cause kidney failure, or bring on a stroke. ¥ Our lifestyle choices and changes in food preferences play a role in increasing the risk of

large-scale food poisoning incidents. ¥ We rely upon strong, national systems of food inspection and efficient notification of

outbreaks of foodborne illness. But it cannot be assumed that we will get the protection we need unless we make our views known to our elected representatives.

CHAPTER

21

ONE FOR THE ROAD

HAVING REACHED THE END, DOES THIS STRIKE YOU AS A BOOK OF RULES, OR A BOOK OF NEW FREEDOMS? Like learning to sail a boat or drive a car, at some point the rules should blur into an instinctive, easy grace; the skills, based upon knowledge, become a part of the fabric of daily life, with its dinner parties and packed lunches, its shopping trips to the supermarket and a safer storage of foods around the home. Much of this book is really a re-telling of traditional ways. There is more science here, and we now know more about why certain foods become risky and how we can increase our protection. So much of our good health will, as the twenty-first century unfolds, continue to depend upon our knowledge and practice of age-old techniques — cooking foods to kill bacteria, washing our hands and work surfaces, cleaning the grime off fruit and vegetables; soap and water, heat and cold. And while the food companies send their scientists to work on new techniques like irradiation and genetic engineering, we continue to rely on simple techniques like the use of salt and sugar, drying, vinegar and fruit acids.

To condense everything into a few points: ¥ Buy it fresh. ¥ Store it correctly. ¥ Wash everything. ¥ Cook it properly. ¥ When in doubt, throw it out.

Don’t run away from the foods you love just because they may be riskier choices. Having digested the tips in this book, it remains your choice. Armed with this knowledge you can decide to avoid a risk, or to embrace the moment and eat the exciting meal in front of you. You can improve your food safety and your health. You can improve your enjoyment of food. Don’t let the details bog you down. Re-read the summaries at the end of each chapter and gradually head towards a safer, clever kitchen. Your health — and that of your family and visitors — will certainly benefit from your efforts. HAPPY AND HEALTHY EATING!

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GLOSSARY bacteria which require oxygen to grow and reproduce ANAEROBIC BACTERIA bacteria which grow and reproduce in the absence of oxygen ASYMPTOMATIC showing no signs or symptoms BACTERIA simple micro-organisms which multiply by dividing in two DETERGENT a mixture of soap and other chemicals such as sodium and potassium salts which lowers the surface tension of water and aids cleaning E.COLI this is the contraction for Escherichia coli bacteria ENTERIC BACTERIA bacteria which infect the digestive system FOOD POISONING any illness caused or thought to be related to the consumption of food or water. It can involve micro-organisms (such as bacteria and viruses), toxins or chemicals FUNGI mushrooms, yeasts and moulds, some of which can cause illness in humans GASTROENTERITIS an inflammation of the stomach and intestine; usually results in diarrhoea GERM a term commonly used to describe the bacteria, parasites, protozoa and viruses that cause illness HISTAMINE a chemical released by the body’s cells which causes allergy-like symptoms HUS haemolytic uraemic syndrome, an illness caused by certain strains of E. coli bacteria. It produces a range of serious symptoms, including anemia resulting from physical damage to red blood cells, and in severe cases, kidney failure. IMMUNITY the body’s natural ability to resist infection MICRO- ORGANISM minute forms of life that are generally visible only with the aid of a microscope (e.g. bacteria, protozoa, viruses and certain parasites) MYCOTOXIN a toxin (poison) produced by a fungi. OFFAL the internal organs and soft tissue that are removed from an animal’s carcass when that animal is butchered AEROBIC BACTERIA

in the context of food poisoning this refers to a protozoa and certain worms PASTEURISATION a process for treating milk and other foods to make and/or keep them safe for consumption. The process involves heating foods to a high temperature for a number of seconds or minutes, according to the formula being used, in order to destroy pathogenic micro-organisms. PATHOGEN something (usually a micro-organism) which causes illness PHAGE certain viruses which attack bacteria PLANKTON tiny plants and animals that tend to be free-floating in fresh water or sea water POTABLE in water, the quality of being safe and fit for humans to drink PROBIOTIC FOOD any food which contains gut micro-organisms that contribute to good health and well being PROTOZOA single-celled animals SANITISE the process of killing and/or removing micro-organisms to safe levels on surfaces such as kitchen benches and crockery SHELF LIFE the period of time during which a processed food remains safe and of good quality, as determined by the manufacturer and stamped on the label or packaging. Sometimes this is indicated to consumers by a ‘best before’ date or ‘use by ’d at e. SPECIES a group of organisms that are very closely related. For example, the Salmonella species. SPORE a dormant state in bacteria that protects genetic and other materials needed for life from the outside environment. Spores are often very resistant to extremes of temperature and dehydration. STERILISATION any process which destroys all micro-organisms from an object STRAIN a variant of a member of a species TOXINS the poisons produced by harmful (pathogenic) bacteria VEROTOXINS powerful toxins produced by certain types of E. coli bacteria VIRUS micro-organisms that are smaller than bacteria and that need to use a host cell to replicate PARASITE

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FURTHER READING Books, articles and pamphlets BRI Food Safety Review, Bread Research Institute Australia Limited, North Ryde, NSW. CHOICE Health Reader, Australian Consumers’ Association, Marrickville, NSW. CHOICE, Australian Consumers’ Association, Marrickville, NSW. Consuming Interest, Australian Consumers’ Association, Marrickville, NSW. Food Regulation Weekly, R&B Communications, Washington DC. Ashton, John and Laura, Ron, Perils of Progress, UNSW Press, 1998. Australia New Zealand Food Authority, Food Standards Code, Information Australia, Melbourne, 1999. Benenson AS (ed.), Control of Communicable Diseases Manual, 16th ed., American Public Health Association, Washington, 1995. Communicable Disease Surveillance Centre, Communicable Disease Report, Public Health Laboratory Service, London. Communicable Disease Surveillance Centre, National Food Surveys 1994–1997, Public Health Laboratory Service, London. Crerar SK, Dalton CB, Longbottom HM and Kraa E, ‘Foodborne disease: current trends and future surveillance needs in Australia’, Medical Journal of Australia, vol 165, 1996, pp. 672–75. Fox, Nicols, Spoiled: the Dangerous Truth About a Food Chain Gone Haywire, Basic Books, 1997. Hanssen M and Marsden J, New Additive Code Breaker, 1990. Hocking AD et al. (eds), Foodborne Micro organisms of Public Health Significance, Australian Institute of Food Science and Technology, NSW Branch, Food Microbiology Group, North Sydney, 1997. Jones, Julie, Food Safety, Egan Press, 1992. Klontz KC, Timbo B, Fein S and Levy A, ‘Prevalence of Selected Food Consumption and Preparation Behaviors Associated with Increased Risks of Food-borne Disease’, Journal of Food Protection, vol. 58(8), 1995, pp. 927–30. Merry, Greg, Food Poisoning Prevention, 2nd ed., Macmillan Education Australia, 1997. Scott, Elizabeth and Sockett, Paul, How to Prevent Food Poisoning: a Practical Guide to Safe

Cooking, Eating and Food Handling, John Wiley & Sons, 1998. Stanton, Rosemary, Rosemary Stanton’s Complete Book of Food and Nutrition, Simon & Schuster, Australia, 1989. Tauxe, Robert V, Emerging Foodborne Diseases: an Evolving Public Health Challenge, Centers for Disease Control and Prevention, Atlanta, Georgia. Varnam, Alan H and Sutherland, Jane P, Milk and Milk Products, Chapman & Hall, 1994. Wills, Ron, McGlasson, Barry, Graham, Doug and Joyce, Daryl, Postharvest: an Introduction to the Physiology and Handling of Fruit, Vegetables and Ornamentals, 4th ed., UNSW Press, 1998.

Websites Australian Consumers’Association WWW.CHOICE.COM.AU Australia New Zealand Food Authority WWW.ANZFA.GOV.AU Biomednet WWW.BIOMEDNET.COM Bread Research Institute Australia WWW.BRI.COM.AU Centers for Disease Control and Prevention, National Center for Infectious Diseases (US) WWW.CDC.GOV CSIRO WWW.DFST.CSIRO.AU Department of Agriculture Food Safety and Inspection Service (US) WWW.FSIS.USDA.GOV Food and Drug Administration (US) WWW.FDA.GOV Food Regulation Weekly (US) WWW.FOODREGULATION.COM Food Science Australia Information Services WWW.FOODSCIENCE.AFISC.CSIRO.AU Fsnet HTTP://OAC.UOGUELPH.CA/RISKCOMM and WWW.EXNET.IASTATE.EDU/ PAGES/ FAMILIES/FS/ HOMEPAGE.HTML Institute of Food Science and Technology (UK) WWW.EASYNET.CO.UK/IFST Institute of Food Technologists (US) WWW.IFT.ORG Medscape WWW.MEDSCAPE.COM NHMRC WWW.NHMRC.HEALTH.GOV.AU Public Health Association of Australia WWW.PHA.ORG.AU Reuters health news service WWW.REUTERSHEALTH.COM US National Library of Medicine (NLM) WWW.NLM.NIH.GOV

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INDEX acetic acid 42 acid foods 40 acidic pH 40 acidity 22, 47, 55 aerobic bacteria 22 Aeromonas spp. 23 aflatoxin 30 agricultural chemicals 33 air-drying machines 137 alcohol 41, 88 alfalfa sprouts 62 algae 22, 89 algae, blue-green 89 allergens 121–22, 156 allergies 15, 121–22, 156 anaerobic bacteria 22 anit-bacterial products 135 antacid medicines 38 antibacterial surface cleansers 35 antibiotic-resistant bacteria 152 antibiotics 42, 151–53 apple juice 31, 93 apples 31 apricots 31 aquaculture 32, 154 arthritis 20 artificial preservatives 41 ascorbic acid (vitamin C) 42 aspartame 153 Aspergillus flavus 30 asthma 35, 50, 120 Australia New Zealand Food Authority (ANZFA) 11 Australian Quarantine and Inspection Service 144 baby foods 131 Bacillus cereus 10, 22, 23, 40, 53, 77, 97, 99–100 backslopping 49 bacon 47 bacteria 19, 124 evolution of 149 faculative 22 growth 21 bacterial spores 40 bain marie 102 barbecues 114 basil 53 beans 121, 124 beer 48, 50, 88, 110 benchtops 135 benzoates 42 benzoic acid 42 Bettelheim, Karl 152

Bifidobacterium bifidum 111 blanching 125 blueberries 124 body temperature, human 21 boiling 88 water 110 bottle feeding 111 bottle foods 133 botulism 11, 82 Brazil nuts 122 bread, sourdough 48 Brucella melitensis 55 brucellosis 55 BSE 65 butter 48, 70 cabana 52 cabanossi 52 cakes 75, 76 Cameron, Scott 34 Campylobacter 10, 12, 34, 54, 60, 63, 145, 148 C. coli 65 C. jejuni 4, 10, 23, 40, 65, 149 cancer risks 146 canned foods 40, 82, 131, 133 cans 86 carbon dioxide 92 carbonation 88 cardiovascular disease 70 carrots 102, 124 casseroles 115 catering 114–15 cattle 85 cauliflower 124 caustic soda 33 celery 102 cereals 84 champagne 88, 110 cheese 20, 46, 48, 55–56, 67, 107 chemotaxis proteins 149 cherries 31 chest freezers 84 chick peas 84 chicken meat 151 chickens 20, 100, 115 children 34 chilli 41, 53 powder 85 chips 54 chlorine 109, 111 treatment 36 chocolate 38, 79–80, 121 chocolates, exploding 80 cholera 28, 109 cholesterol 47, 54, 69–70 Christmas puddings 41

Chrysoporium 80 ciguatera 71 cinnamon 41 clams 71 Clostridium 55 C. botulinum 24, 40, 54, 82, 149 C. perfringens 10, 22, 24, 40, 99 clothing 141 cloves 41 coccus 19 cockles 28, 72 cockroach infestation 144 coconut 85 coffee 88 colitis 41 colon cancer 41 Commonwealth Department of Industry Science and Tourism 13 complaints 142 computerised sinks 146 conserving the environment 85 cooking 39, 154 coral cod 10 coral trout 10 coriander 53 corned beef 46, 47 corrosion 82, 131 cottonseed 121 crabs 73 cream 75–76 Crerar, Scott 12, 148 Crohn’s disease 41 cruise illness 107–108 Cryptosporidium 10, 36, 89, 92, 109, 113 C. parvum 31, 40, 90 cucumber 102 Cummings, John 41 custard 21, 75–76 cutting boards 135 Cyclospora cayetanensis 149, 151–52 dairy foods 21, 40, 46, 54 defrosting 83–84, 114, 129 delicatessens 46, 50–52 Department of Industry Science and Tourism, Commonwealth 13 desserts 28 detergent 135 Devon 52–53 diarrhoea 10, 11, 93 dinoflagellates 71 dish cloths 137

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dishwashers 137 disinfectants 117, 135 chemical 109 distillers 92 doner kebabs 99 dried foods 131 dried fruits 50 drinking water 20 drinks, carbonated 109 drying 40, 47, 55 duck 20, 67 Escherichia coli (E.coli) 22, 24, 25, 34, 35, 40, 49, 55–56, 63, 65, 77, 92, 94 E.coli O111 49–50, E.coli O157:H7 4, 10, 48, 92, 95, 145–46, 149–51 Easter eggs 80 eczema 35, 50, 120 education 144 eggs 20, 21, 70, 73, 76, 84, 102, 121 raw 76 whites 76 yolks 125 environment 85 evolution of bacteria 149 facial hair 77 faculative bacteria 22 fats 70 saturated 69–70 unsaturated 69 fatty acids 69 fermentation 47, 48, 64 fermented foods 48 fermented meat products 50 fertilisers 93 filters 91, 92 fish 73 fish and chip shops 99 flagella 19, 149 flu-virus, bird 151 food additives 42, 43 allergens 121 allergy 120, 122 bottled 133 canned 131 companies 147 dried 131 irradiation 145 manufacturer 147 mouldy foods 86 nutrition 60 packaged 133 perishable 129

poisoning 8, 10, 16, 20, 38, 120, 148 preparation 39, 103, 108, 115, 134, 141 preservation 39 processing 140 raw 134 regulations 156 riskier 112, 115 recalls 14, 15 safer 112 safety 140, 153, 155 serving 115 storage 39, 50–51, 115, 124–25, 129, 131, 140 takeaway 104 thawing 83–84, 129 food workers, sickness 102 food-borne illness 8, 12, 13, 28, 65, 120, 144 Foodnet 11 foreign objects 15–16 frankfurts 15 freezability of common food types 125 freezers 21, 83, 125 power cuts 129–30 storage times 132 tips 129 freezing food 39, 124, 129 frequently asked questions 126–27 fruit 130 re-freezing 83–84 vegetables 130 fritz 52 frozen foods 77, 82 meat 51 fruit 28, 59–60, 121 freezing 130 fruit cakes 41 fruit juice 5, 21, 50, 88, 92, 131 fresh 110 fungi 62 Gail Vines 41 Garibaldi mettwurst 34, 49, 150 garlic 41, 53 gastroenteritis 118–19 gelati 78 gene technology 154 genetic engineering 42, 153, 155 genetic sequences 145 Giardia lamblia (or Giardia duode nalis) 31, 34, 40, 89–90, 92, 109, 113 ginger 53 glass 142

gluten 15, 84 grapes 31 haemolytic uremic syndrome (HUS) 49, 150 ham 15, 20, 46, 51 hamburger mince 41 hamburger, rare 65 hamburgers 5, 95–96, 151 hand sanitisers 146 handwashing 136–37 hayfever 35 Hazard Analysis Critical Control Points (HACCP) 140–43, 156 headaches 50 hepatitis A 10, 29, 37, 40, 70, 73, 89, 151 hepatitis E 37, 151 herbs 46, 53 histamines 35, 72, 120 honey 83 honey-cured ham 47 hospitality industry 108 hot box 102 hot dogs 96 human body temperature 21 hydrogenated vegetable oils 70 hydroperiodide tablets 111 hydroponics 154 hygiene, personal 136 ice 88, 94, 110 icecream 20, 77-78, 79, 83–84 homemade 77 soft serve 79 idli 48 immunity, reduced 36 invasion genes 149 iodine 109, 111 iron 69 irradiation 41 irritable bowel syndrome 41 jams 46, 56, 83, 153 juices 40 apple 31, 93 fresh 110 fruit 5, 21, 50, 88, 92, 131 orange 93 vegetable 93 kebabs 67 kissing 70 kitchen benches 135 Kosovo 85

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Lactobacillus L. acidophilus 111 L. casei 111 lactose 111 leftovers 115, 133 reheating 107 leg of ham 51 lentils 84, 121 lettuce 102, 124 Listeria 10, 34, 36, 55–56, 73 L. monocytogenes 25, 40, 41, 54–56, 60, 63, 70, 72–73, 77, 79, 92, 94, 96–97, 149–50, 154 lobsters 73 lunches homemade 117–18 school 117–18 mad cow disease 65, 151 maize 22 margarine 70 Marmite 83 marshmallows 76 mayonnaise 76, 98, 102 Meals on Wheels 76 meat 20, 21, 70 beef 46, 47, 52 chicken 151 fermented meat products 50 frozen 51 marinated 67 minced 65–66, 151 pie 67 port rolls 101 raw 32, 68 roasts 52, 67 salty 53 spoiled 64 undercooked 67 meringues 76 mettwurst 150 mice 75, 143 microwaves 67, 114–15 milk 20, 88, 94, 121 breast, 111 goat’s 111 powdered milk 21 unpasteurised 94 milkshakes 110 mince 151 mincing 52 miso 48 molluscs 72, 121 monosodium glutamate (MSG) 33 mortadella 52 mould 16, 19, 30, 40, 86, 124

mouldy foods 86 mousse 76 MSG 33 mushrooms 10, 41, 62 mussels 28, 71-72 mustard seeds 41 mycotoxins 22 National Association of Testing Authorities 144 natto 48 natural casings 53 natural poisons 19 neurotoxins 72 nisin 42 nitrates 41–42, 50, 82 nitrites 41–42, 50 nitrosamines 50 Norwalk virus 10, 29, 40, 70–71, 89 nursing mothers 36 nuts 22, 84, 121 oils 53 olives 48, 53 Omega 3 fatty acids 69 orange juice 93 organic farming 154 oysters 28, 69–72 packaged foods 133 paprika 53 parasites 32 parties 114 pasta 115 pasteurisation 40, 47, 55–56 pate 20, 46, 56, 73 pathogenicity islands 150 patulin 30, 86 peaches 31 peanuts 15, 22, 30, 121 allergies 122 peanut butter 30, 83, 85 pears 31 peas 83, 121 pepperoni 52 pest control 140 pesticide residues 32 pesticides 146 pH 22, 150 of the stomach 149 phages 149 pickled vegetables 46 picnics 104, 107, 114 tips 103 pine nuts 121 pizza 52, 100–101 plasmids 149

plastic casings 53 containers 115 packaging 51 plums 31 Polish sausage 52 polymerase chain reaction 145 poppy seed 121 pork rolls 101 potato crisps 50 potatoes 9, 60–61, 155 poultry 66 powdered milk 21 powdery scab 61 prawns 41, 69, 71 pregnant women 36, 66 preserves 56 Prince Charles 55 propionates 42 propionic acid 42 probiotic 39, 111 prosciutto 47 protozoa 90, 124 Pulp Fiction 95 radiolytic products 145 raw meat 32 ready-to-eat products 154 red emperor 10 re-freezing 83–84 refrigeration 115, 125 refrigerators 21, 125, 128–29 power cuts 130 storage times 132 Reiter’s syndrome 20 restaurants 108, 147 reverse osmosis filters 92 rhubarb 9, 131 rice 99–100, 155 reheated 100 rissoles 66 roast beef 52 Rotavirus 10, 89–90 rotten egg gas 84 rust 82, 131 salad bars 96–97, 98, 143 salad dressing 76 salads 28, 62–63, 71, 97, 102, 113 salamis 41, 46, 48–50, 52, 82 salmon 32 Salmonella 5, 9, 10, 12, 20, 26, 34, 40, 50, 54, 61–63, 65–66, 76–77, 79, 85, 93–94, 143, 145, 147–49 S. enteritidis 19, 72, 75–76, 78, 151 S. oranienberg 78

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S. typhi 39 S. typhimurium 19, 101 S. typhimurium DT104 150–51 salmonellosis 11, 148 salt 154 salting 40, 47 salty foods 47 salty meats 53 sandwiches 101, 117–18 fillings 102 sanitising foot baths 141 sanitising systems 141 sashimi 32, 70 satay sticks 67 sauerkraut 48, 50 sausage products 48 sausages 15, 50, 52, 65–66, 82 scourers 137 scrombroid 71 seafood 69–72 seasonings 67 septicaemia 20 sesame seed 85, 121 sewage 71, 152 shellfish 28, 70, 71, 121 Shigella 10, 20, 26, 149 shrimp 71 sickness, food workers 102 slushies 110 small round structured virus 10, 72 smallgoods 46, 47, 52 smoking 47 smoothies 110 smorgasbords 97 snapper 10 soap 35, 135, 137 sodium nitrite 47 soft drinks 50, 88, 131, 153 Solanin 61 sorbates 42 sorbic acid 42 SOS genes 150 soup 40 sourdough bread 48 soy 84, 121 beans 85, 155 products 48 sauce 48 spaghetti bolonaise 65 Spanish mackerel 10 spices 41, 46, 53 spinach 9 spirillum 19 spores 40 squash, virus resistant 155 squid 70 Staphylococcus 54, 65, 97

S. aereus (‘Golden Staph’) 10, 22, 26, 40, 47, 76–77, 94, 99, 149 starter culture 111 steaks 67 stir frying 67, 115 stomach acid 38 stomach pH 38 Strasbourg sausage 52 strawberries 41, 151 sufu 48 sugar 88, 154 sulfites 42 sulfur dioxide 42, 50 sunflower seed 121 supermarkets 139, 147 chains, Australian 81 sushi 32, 70 Sydney water crisis 92, 109 tacos 65 takeaway food 104 tamari 48 Tauxe, Robert V. 154 tea 88, 110 teatowels 137 tempeh 48 temperatures, safe 22 tetraglycine 111 thawing foods 83–84, 129 thermometers 115, 146 toadstools 10 tomato sauce 153 tomatoes 102, 121, 124, 155 sundried 54 tooth decay 93 town water 88 toxins 19, 22, 71, 86, 149 Toxoplasma gondii 32, 66 training 144 transposons 150 tree nuts 121 turkey 115 Turkish Delight 80 typhoid 109 UHT processing 55 milk 40 UK Public Health Laboratory Service 78 ultraviolet light 41 US Centers for Disease Control and Prevention (CDC) 11 US Department of Agriculture 32 US Department of Agricultureís Food Safety Branch 11

US Food and Drug Administration 89, 146 Use-by dates 85–86, 131 vacuum packing 42, 83 vegetable juices 93 vegetables 28, 59–60 freezing 130 pickled 46 vegetarian meat substitutes 84–85 Vibrio V. cholerae 27, 39, 40, 72, 135, 149 V.funissii 27 V. hollisae 27 V. mimicus 27 V. parahaemolyticus 10, 27, 149 V. vulnificus 27, 36, 149 video cameras 146 vinegar 50, 54 viruses 19, 28, 29, 40, 124 vitamins 59 vitamin C 42 vitamin D 70 Wallis Lake 73, 151 warehouses 140 warming trays 115 water 88 bottled 88, 91, 109, 110 carbonated 109, 110 contaminated 91 disinfection 109, 111 drinking 107, 111 filters 91 hotel water 110 suppiles 5, 109 town water 88 watermelon 124 wheat 22, 121 whelks 72 wine 48, 50, 110 winkles 72 yabbies 73 yeasts 19, 30, 40, 124 Yersina 10 Y. enterocolitica 27, 149 yoghurt 48–49, 111 zinc 69 Zygosaccharomyces rouixii 80