Impact of Processing on Food Safety

264 Pages·1999·9.083 MB·English

by  Christine M. Bruhn (auth.), Lauren S. Jackson, Mark G. Knize, Jeffrey N. Morgan (eds.)

IMPACT OF PROCESSING
ON FOOD SAFETY
ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY
Editorial Board:
NATHAN BACK, State University of New York at Buffalo
IRUN R. COHEN, The Weizmann Institute of Science
DAVID KRITCHEVSKY, Wistar Institute
ABEL LAJTHA, N. S. Kline Institute for Psychiatric Research
RODOLFO PAOLETTI, University of Milan
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IMPACT OF PROCESSING
ON FOOD SAFETY
Edited by
Lauren S. lackson
V.S. Food and Drug Administration
Summit-Argo, IlIinois
Mark G. Knize
Lawrence Livennore National Laboratory
Livennore, Califomia
and
leffrey N. Morgan
V.S. Environmental Protection Agency
Cincinnati, Ohio
Springer Science+Business Media, LLC
Llbrarll of Congress Cataloglng-ln-Publlcatlon Data
Impact of processlng on food safety I edlted by Lauren S. Jackson,
Mark G. Knlze and Jeffrey N. Morgan.
p. cm. -- (Advances In experimental medlclne and blology ; v.
459)
Includes blbllographlcal references and index.
ISBN 978-1-4613-7201-1 ISBN 978-1-4615-4853-9 (eBook)
DOI 10.1007/978-1-4615-4853-9
1. Food lndustry and trade--Congresses. 2. Food--Contamlnatlon-
-Congresses. 3. Food--E~fects of heat on--Congresses. I. Jackson,
Lauren S. II. Knlze, Mark G. III. Morgan, Jeffrey N. IV. Serles.
TP372.5.I53 1999
664--dc21 99-11924
CIP
Proceedings of the American Chemical Society Symposium on Impact of Processing on Food Safety,
held April 14 - 18, 1997, in San Francisco, Califomia
ISBN 978-1-4613-7201-1
©1999 Springer Science+Business Media New York
Originally published by Kluwer Academic !Plenum Publishers in1999
Softcover reprint of the hardcover 1s t edition 1999
All rights reserved
No part ofthis book may be reproduced, stored in a retrieval system, or transmitted in any form or by any
means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written
permission from the Publisher
PREFACE
The contents of this book are the proceedings of the ACS symposium, "Impact of
Processing on Food Safety," which was held April 16-17, 1997, at the American Chemical
Society National Meeting in San Francisco, CA. This symposium brought together re
searchers from diverse backgrounds in academia, government, and industry. Twenty
speakers discussed topics ranging from the regulatory aspects of food processing to the
microbiological and chemical changes in food during processing.
The main goal of food processing is to improve the microbial safety of food by de
stroying pathogenic and spoilage organisms. Food processing can also improve food
safety by destroying or eliminating naturally occurring toxins, chemical contaminants, and
antinutritive factors. Unfortunately, processing can also cause chemical changes that result
in the formation of toxic or antinutritive factors. The purpose of this book is to summarize
our knowledge of both the beneficial and deleterious effects of processing. Chapter I con
siders the consumer's perceptions about food contaminants and food processing. Chapter 2
summarizes the effects of traditional and nontraditional processing methods on microor
ganisms in food. Chapters 3-6 review the effects of processing on lipids (fatty acids and
cholesterol) in food. Changes in the nutritive value of vitamins and minerals as a result of
processing are discussed in chapter 7. Chapter 8 concentrates on how processing reduces
the allergenicity of some foods. The remaining 8 chapters of the book summarize the ef
fects of processing on the formation and destruction of chemical contaminants (glycoal
kaloids, Iysinoalanine, heterocyclic aromatic amines, pesticides, environmental
contaminants, veterinary drug residues, heavy metals, and mycotoxins) in food.
The symposium organizers would like to thank the ACS Division of Agricultural and
Food Chemistry for their approval and financial support of this symposium. We also ex
press our gratitude to the following sponsors: International Fragrances and Flavors (IFF),
Flavor and Extract Manufacturers Association (IFF), and Quadralux, Inc. Most of all, the
organizers gratefully acknowledge the contribution of the speakers. Without their dedica
tion, expertise, and hard work, publication of these proceedings would not be possible.
Lauren S. Jackson
Mark G. Knize
Jeffrey N. Morgan
v
CONTENTS
1. Consumer Perceptions and Concerns about Food Contaminants
Christine M. Bruhn
2. Microorganisms and Microbial Toxins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
D. S. Reid and L. J. Harris
3. Food Processing and Lipid Oxidation 23
J. Bruce German
4. Impact of Processing on Formation of Trans Fatty Acids 51
J. M. King and P. J. White
5. Impact of High-Temperature Food Processing on Fats and Oils. . . . . . . . . . . . . . 67
Kathleen Warner
6. Cholesterol Oxidation Products: Their Occurrence and Detection in Our
Foodstuffs ................................................... 79
Pearlly S. Van
7. The Impact of Food Processing on the Nutritional Quality of Vitamins and
Minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Manju B. Reddy and Mark Love
8. Impact of Processing on Food Allergens 107
Susan L. Hefle
9. Postharvest Changes in Glycoalkaloid Content of Potatoes 121
Mendel Friedman and Gary M. McDonald
10. Lysinoalanine in Food and in Antimicrobial Proteins 145
Mendel Friedman
II. Influence of Feeding Alkaline/Heat Processed Proteins on Growth and Protein
and Mineral Status of Rats ...................................... 161
G. Sarwar, M. R. L' Abbe, K. Trick, H. G. Botting, and C. Y. Ma
vii
viii Contents
12. Food Heating and the Formation ofHeterocyc1ic Aromatic Amine and
Polycyclic Aromatic Hydrocarbon Mutagens/Carcinogens . . . . . . . . . . . . . 179
Mark G. Knize, Cynthia P. Salmon, Pilar Pais, and James S. Felton
13. Effects of Processing on Heavy Metal Content of Foods 195
Jeffrey N. Morgan
14. Polychlorinated Biphenyls, Polybrominated Biphenyls, and Dioxin Reduction
during Processing/Cooking Food ................................. 213
Mary E. Zabik and Matthew 1. Zabik
IS. The Effect of Processing on Veterinary Residues in Foods 233
William A. Moats
16. Effect of Processing on Fusarium Mycotoxins 243
Lauren S. Jackson and Lloyd B. Bullerman
Index 263
1
CONSUMER PERCEPTIONS AND CONCERNS
ABOUT FOOD CONTAMINANTS
Christine M. Bruhn
Center for Consumer Research
University of California
Davis, California 95616-8598
1. ABSTRACT
More consumers are concerned about microbiological hazards than any other area.
Pesticide residues generate concern, especially among low income consumers with less
formal education. Use of antibiotics and hormones in animal production is considered a
serious hazard by fewer consumers. Consumer attitudes are influenced by media coverage.
An increasing number of consumers expect food producers and retailers to assume a major
role in providing safe food. A majority of consumers express interesting in purchasing ir
radiated food when specific benefits are described and the percentage increases when irra
diation is more fully described. In actual market experiences, irradiated produce and
poultry have been well received. Similarly, most consumers are positive toward biotech
nology, with greatest support for environmental applications. The scientific community
should use the media to reach the public with information identifying risks and protective
strategies, including the use of new technology.
2. INTRODUCTION
The lay person may view a contaminant as something unwanted and not naturally
present in a food. This review will focus on consumer attitudes toward intentional addi
tions or modifications in processing which some may consider contamination. To place
concerns in perspective, consumer confidence in the safety of food in the supermarket has
increased in the last ten years. In 1989,81% were mostly or completely confident in the
safety of food in the supermarket. By 1992, confidence dipped to 72%. It gradually in
creased to 84% in 1996 (Abt Associates, 1996; Opinion Research, 1990).
Impact q{ Processing on Food Safety. edited by Jackson et aI.,
Kluwer Academic I Plenum Publishers, New York, 1999.
2 C. M. Bruhn
3. CONSUMER FOOD SAFETY CONCERNS
Microbiological contamination is the consumer's greatest concern, followed by
chemical contamination, such as pesticide or animal drug residues. Nationwide surveys by
the Food Marketing Institute indicated more people volunteer concerns about microbio
logical hazards than any other potential food safety issue. From 1992 to 1996 volunteered
concern about microbiological safety increased from 36% to 49% (Abt Associates, 1996).
When concern about contamination by bacteria or germs was specifically asked, 77% ac
knowledged it as a serious hazard. More consumers consider this a serious hazard than
any other potential food risk.
Pesticide residues continue to generate concern among a major segment of the popu
lation, with 66% of consumers ranking it a serious hazard in 1996. Concern about pesti
cides has decreased from 82% in 1989 to the current level.
Concern about other food safety areas has also decreased. Those expressing serious
concern with antibiotics and hormones used in poultry or livestock decreased from 61 % in
1989 to 42% in 1996. Those rating the use of nitrites in food as a serious hazard decreased
from 44% in 1989 to 24% in 1996, while those rating use of additives and preservatives as
a serious hazard decreased from 30% in 1989 to 20% in 1996.
Concern about pesticide residue contamination seems logical since pesticides are
used for their toxic effect. Several attitude studies noted that concern about pesticide resi
dues was higher among those with lower income and less formal education (Packer, 1992;
Center for Produce Quality, 1992; Eom, 1992). Eom (1992) found that consumers with
less than $15,000 income per year were willing to pay a higher price premium to reduce
the risk of pesticide residues, $0.83 per unit compared to $0.64 and $0.58 per unit among
persons with income of $15,000--45,000 or more than $45,000.
Concern also could impact produce consumption. In anticipation of a report from the
National Academy of Science, consumers were asked what they would do if pesticide regu
lations were considered inadequate to account for children's risks (Center for Produce Qual
ity, 1992). Most consumers (93%) indicated they would wash produce better, while many
(63%) would peel the skin off produce. However, 15% said they would reduce the amount
of produce served. This response, which is not consistent with recommendations to increase
the consumption of fruits and vegetables, was highest among those with the lowest income.
Of those with income less than $15,000 per year, 33% said they would reduce the amount of
produce served, compared to 8% among those with income above $50,000. Less formal
education was also related to the tendency to reduce produce consumption, with 20% of
those with a high school education or less reporting this response, compared to 8% for those
with post graduate schooling. Response also differed by race with 25% of non-Caucasians
indicating they would reduce consumption compared to 12% of Caucasians.
Correspondingly, interest in organic production was highest among those with less
formal education, with 31 % of those with only some high school education expressing an
interest in organic produce compared to 18% of college graduates (Packer, 1992). Those
with a lower income also showed greater interest in organic products with 32% of those
with an annual income of$12,500 saying organic production was important in produce se
lection compared to 14% among those with income of $50,000 or more. Preference for or
ganic among lower income consumers was unexpected since organic products generally
demand a premium price in the marketplace.
Many consumers perceive organic as a pesticide-free production method (Jolly et
aI., 1989). This misconception may be corrected when the organic standards board recom
mendations are accepted. The Organic Foods Production Act of 1990 directed the U.S. De-
Consumer Perceptions and Concerns about Food Contaminants 3
partment of Agriculture to implement federal rules covering organic farming. The advi
sory body, the National Organic Standards Board, has developed a set of recommendations
to be used as a basis of USDA regulation. The National Organic Standards Board clearly
indicates that organic is a not a pesticide-free claim, but rather a system of managing
crops and livestock which emphasized natural feeds, medications, pest control methods
and soil inputs (Food Chemical News, 1996). It will be interesting to track efforts made to
inform consumers about the true nature of organic production and the affect of this defini
tion on consumer purchase.
Natural toxicants seldom generate high levels of concern. Natural is often equated
with safe and wholesome. Except for consumption of toad stools, or red tide affecting sea
food, people seldom hear about the dangers of natural toxins. In a California survey, peo
ple were surprised when they heard that common foods like peanut butter or organic apple
juice may contain natural toxins. That pesticides may prevent the development of hazard
ous natural toxins was new information and not believed by some consumers (Bruhn et aI.,
1998). Consumer education is needed in this area.
Similarly some in the food industry were unaware of the potential hazards associ
ated with their product. That E. coli 0 157:H7 could survive in a juice product was not rec
ognized by the Odwalla company. A fresh apple juice manufacturer in Northern California
claimed their product was safe because the juice was squeezed in small batches and imme
diately frozen. Freezing isn't effective, against E. coli 015 7:H7 but pasteurization by heat
or energy are protective. Food safety education should be directed toward the industry as
well as consumers.
4. INFLUENCES ON CONSUMER CONCERN
Concerns are shaped by the media, the food industry, and the consumer's own
knowledge and perception. Surveys indicate people obtained most of their information
about food safety from the media with television first followed by newspapers and maga
zines (Bruhn et aI., 1992; Hoban, 1994; Hoban and Kendall, 1993). Other people were
also a significant source of information. Many people were skeptical about stories in the
media and evaluated information sources to judge credibility. Consumers consider how
frequently they heard a message, the credibility of the source, and if the information was
reasonable to them. Consumers considered health authorities, such as the American Medi
cal Association or the American Dietetic Association, as the most credible, followed by
university scientists and regulatory groups like FDA. The food industry, activist groups,
and retailers were considered least credible (Bruhn et aI., 1992; Hoban, 1994). No source
was believed by everyone.
5. RESPONSIBILITY FOR SAFE FOOD
An interesting shift has occurred in consumer perception of responsibility for safe
food. The national Food Marketing Institute survey recorded on whom consumers rely to
ensure the products they bought in the supermarket were safe. In 1986 most consumers
(48%) responded "yourself as an individual" (Abt Associates, 1996). The government re
ceived the second most frequent response with 33%. Over time consumer reliance has
shifted. In 1996, fewer consumers relied on themselves, only 25%, and fewer counted on
the government, 21 %. An increased number of consumers look to manufacturers and food