Handbook of
Food Preservation
Second Edition
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page i
FOOD SCIENCE
AND TECHNOLOGY
Editorial Advisory Board
Gustavo V. Barbosa-Cánovas Washington State University−Pullman
P. Michael Davidson University of Tennessee−Knoxville
Mark Dreher McNeil Nutritionals, New Brunswick, NJ
Richard W. Hartel University of Wisconsin−Madison
Lekh R. Juneja Taiyo Kagaku Company, Japan
Marcus Karel Massachusetts Institute of Technology
Ronald G. Labbe University of Massachusetts−Amherst
Daryl B. Lund University of Wisconsin−Madison
David B. Min The Ohio State University
Leo M. L. Nollet Hogeschool Gent, Belgium
Seppo Salminen University of Turku, Finland
J
ohn H. Thorngate III Allied Domecq Technical Services, Napa, CA
Pieter Walstra Wageningen University, The Netherlands
John R. Whitaker University of California−Davis
Rickey Y. Yada University of Guelph, Canada
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page ii
Handbook of
Food Preservation
Second Edition
edited by
M. Shafiur Rahman
CRC Press is an imprint of the

Taylor & Francis Group, an informa business
Boca Raton London New York
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page iii
CRC Press
Taylor & Francis Group
6000 Broken Sound Parkway NW, Suite 300
Boca Raton, FL 33487-2742
© 2007 by Taylor & Francis Group, LLC
CRC Press is an imprint of Taylor & Francis Group, an Informa business
No claim to original U.S. Government works
Printed in the United States of America on acid-free paper
10 9 8 7 6 5 4 3 2 1
International Standard Book Number-10: 1-57444-606-1 (Hardcover)
International Standard Book Number-13: 978-1-57444-606-7 (Hardcover)
This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted
with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to
publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of
all materials or for the consequences of their use.
No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or
other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any informa-
tion storage or retrieval system, without written permission from the publishers.
For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://
www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC) 222 Rosewood Drive, Danvers, MA 01923,
978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For orga-
nizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged.
Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for
identification and explanation without intent to infringe.
Library of Congress Cataloging-in-Publication Data
Handbook of food preservation / editor M. Shafiur Rahman. 2nd ed.
p. cm. (Food science and technology ; 167)

Includes bibliographical references and index.
ISBN-13: 978-1-57444-606-7 (alk. paper)
ISBN-10: 1-57444-606-1 (alk. paper)
1. Food Preservation. I. Rahman, Shafiur. II. Title. III. Series.
TP371.H26 2007
664’.028 dc22 2006100043
Visit the Taylor & Francis Web site at

and the CRC Press Web site at

CRC_DK3871_fm.qxd 6/14/2007 18:12 Page iv
Contents
Preface ix
Acknowledgments xi
Editor xiii
Contributors xv
Part 1 Preservation of Fresh Food Products
1. Food Preservation: Overview 3
Mohammad Shafiur Rahman
2. Postharvest Physiology of Fruit and Vegetables 19
Vijay Kumar Mishra and T.V. Gamage
3. Postharvest Handling and Treatments of Fruits and Vegetables 49
Vijay Kumar Mishra and T.V. Gamage
4. Postharvest Handling of Grains and Pulses 73
Ajit K. Mahapatra and Yubin Lan
5. Minimal Processing of Fruits and Vegetables 137
Conrad O. Perera
6. Postharvest Handling and Preservation of Fresh Fish and Seafood 151
Linus U. Opara, Saud M. Al-Jufaili, and Mohammad Shafiur Rahman
7. Postharvest Handling of Red Meat 173

Isam T. Kadim and Osman Mahgoub
8. Postharvest Handling of Milk 203
Nejib Guizani
Part 2 Preservation Using Chemicals and Microbes
9. Fermentation as a Method for Food Preservation 215
Nejib Guizani and Ann Mothershaw
10. Natural Antimicrobials for Food Preservation 237
Eddy J. Smid and Leon G. M. Gorris
11. Antioxidants in Food Preservation 259
Jan Pokorny
12. pH in Food Preservation 287
Mohammad Shafiur Rahman
v
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page v
vi Contents
13. Nitrites in Food Preservation 299
Mohammad Shafiur Rahman
Part 3 Preservation by Controlling Water, Structure,
and Atmosphere
14. Modified-Atmosphere Packaging of Produce 315
Leon G. M. Gorris and Herman W. Peppelenbos
15. Glass Transition and State Diagram of Foods 335
Mohammad Shafiur Rahman
16. Food Preservation and Processing Using Membranes 365
Shyam S. Sablani
17. Stickiness and Caking in Food Preservation 387
Bhesh R. Bhandari
18. Drying and Food Preservation 403
Mohammad Shafiur Rahman and Conrad O. Perera
19. Osmotic Dehydration of Foods 433

Mohammad Shafiur Rahman
20. Water Activity and Food Preservation 447
Mohammad Shafiur Rahman and Theodore P. Labuza
21. Surface Treatments and Edible Coatings in Food Preservation 477
Elizabeth A. Baldwin
22. Encapsulation, Stabilization, and Controlled Release of Food Ingredients
and Bioactives 509
Ronald B. Pegg and Fereidoon Shahidi
Part 4 Preservation Using Heat and Energy
23. Pasteurization and Food Preservation 571
M. N. Ramesh
24. Canning and Sterilization of Foods 585
M. N. Ramesh
25. Cooking and Frying of Foods 625
M. N. Ramesh
26. Food Preservation by Freezing 635
Mohammad Shafiur Rahman and Jorge F. Velez-Ruiz
27. Freezing–Melting Process in Liquid Food Concentration 667
Mohammad Shafiur Rahman, Mushtaque Ahmed, and Xiao Dong Chen
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page vi
Contents vii
28. Microwave Pasteurization and Sterilization of Foods 691
Jasim Ahmed and Hosahalli S. Ramaswamy
29. Ultrasound in Food Processing and Preservation 713
P.J. Torley and Bhesh R. Bhandari
30. Food Preservation Aspects of Ohmic Heating 741
Marybeth Lima
31. Light Energy in Food Preservation 751
Mohammad Shafiur Rahman
32. Irradiation Preservation of Foods 761

Mohammad Shafiur Rahman
33. Pulsed Electric Fields in Food Preservation 783
Humberto Vega-Mercado, M. Marcela Gongora-Nieto,
Gustavo V. Barbosa-Canovas, and Barry G. Swanson
34. High-Pressure Treatment in Food Preservation 815
Enrique Palou, Aurelio Lopez-Malo, Gustavo V. Barbosa-Canovas, and
Barry G. Swanson
35. Applications of Magnetic Field in Food Preservation 855
Jasim Ahmed and Hosahalli S. Ramaswamy
36. Combined Methods for Food Preservation 867
Lothar Leistner
37. Update on Hurdle Technology for Mild and Effective Preservation of Foods 895
Lothar Leistner
Part 5 Enhancing Food Preservation by Indirect Approach
38. Packaging as a Preservation Technique 907
Mohammad Shafiur Rahman
39. Types of Packaging Materials Used for Foods 917
Robert H. Driscoll and Mohammad Shafiur Rahman
40. Food Packaging Interaction 939
Shyam S. Sablani and Mohammad Shafiur Rahman
41. Hygienic Design and Sanitation 957
Mohammad Shafiur Rahman
42. Hazard Analysis and Critical Control Point (HACCP) 969
Titus De Silva
43. Good Manufacturing Practice (GMP) 1011
Titus De Silva
44. Commercial Considerations: Managing Profit and Quality 1031
Anne Perera and Gerard La Rooy
Index 1055
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page vii

CRC_DK3871_fm.qxd 6/14/2007 18:12 Page viii
ix
Preface
Food preservation is an action or a method of maintaining foods at a desired level of properties or nature
for their maximum benefits. In general, each step of handling, processing, storage, and distribution
affects the characteristics of food, which may be desirable or undesirable. Thus, understanding the effects
of each preservation method and handling procedure on foods is critical in food processing. The first edi-
tion of this book was the first definitive source of information on food preservation. It was well received
by readers and became a bestseller and was also translated into Spanish by Acribia, Spain, in 2003.
Appreciation from scientists, academics, and industry professionals around the globe encouraged me to
produce an updated version. This edition has been developed by expanding the previous one with the
addition of new chapters and updating most of the chapters of the first edition. The 25 chapters in the
first edition are now expanded to 44 chapters.
The processing of food is no longer as simple or straightforward as in the past. It is now moving from
an art to a highly interdisciplinary science. A number of new preservation techniques are being developed
to satisfy current demands of economic preservation and consumer satisfaction in nutritional and sensory
aspects, convenience, absence of preservatives, low demand of energy, and environmental safety. Better
understanding and manipulation of these conventional and sophisticated preservation methods could help
to develop high-quality, safe products by better control of the processes and efficient selection of ingredi-
ents. Food processing needs to use preservation techniques ranging from simple to sophisticated; thus, any
food process must acquire requisite knowledge about the methods, the technology, and the science of
mode of action. Keeping this in mind, this edition has been developed to discuss the fundamental and prac-
tical aspects of most of the food preservation methods important to practicing industrial and academic
food scientists, technologists, and engineers. Innovative technology in preservation is being developed in
the food industry that can extend shelf life; minimize risk; is environment friendly; or can improve func-
tional, sensory, and nutritional properties. The large and ever-increasing number of food products and new
preservation techniques available today creates a great demand for an up-to-date handbook of food preser-
vation methods. This book emphasizes practical, cost-effective, and safe strategies for implementing
preservation techniques and dissects the exact mode or mechanisms involved in each preservation method
by highlighting the effect of preservation methods on food properties.

The first edition was divided into four parts. Part 1: Preservation of Fresh Food Products encompassed
the overview of food preservation and postharvest handling of foods. Part 2: Conventional Food
Preservation Methods presented comprehensive details on glass transition, water activity, drying, con-
centration, freezing, irradiation, modified atmosphere, hurdle technology, and the use of natural preser-
vatives, antioxidants, pH, and nitrites. Part 3: Potential Food Preservation Methods detailed new and
innovative preservation techniques, such as pulsed electric fields, ohmic heating, high-pressure treat-
ment, edible coating, encapsulation, light, and sound. Part 4: Enhancing Food Preservation by Indirect
Approach described areas that indirectly help food preservation by improving quality and safety. These
areas are packaging and hazard analysis.
The second edition is divided into five parts. The grouping of Parts 2 and 3 in the first edition could
not be a clear approach since it was not easy to separate the conventional and the potential methods. In
the second edition, a better rational approach is used for grouping. The basis of grouping is the mode of
preservation method.
Part 1: Preservation of Fresh Food Products encompasses the overview of food preservation and posthar-
vest handling of foods, which includes physiology of fresh fruits and vegetables; handling and postharvest
treatments of fruits and vegetables; and postharvest handling of grains and pulses, fish and seafood, red
meat, milk; and also minimal processing of fruits and vegetables. This part can be read independently for
those who want a basic background in postharvest technology for foods of plant and animal origin. It also
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page ix
x Preface
gives valuable background information on the causes of food deterioration and classification of food preser-
vation methods with the mode of their action.
Part 2: Preservation Using Chemicals and Microbes presents comprehensive preservation methods
based on additives of chemical or microbiological nature, including fermentation, antimicrobials, antiox-
idants, pH-lowering agents, and nitrides. Each chapter covers the mode of preservation actions and their
applications in food products.
Part 3: Preservation by Controlling of Water, Structure, and Atmosphere details preservation methods
based on physical nature, including modified-atmosphere packaging; glass transition and state diagram;
membrane technology; stickiness and caking; drying, including osmotic dehydration; water activity; sur-
face treatment and edible coating; encapsulation and controlled release.

Part 4: Preservation Using Heat and Energy describes preservation methods based on thermal and
other forms of energy, including pasteurization, canning and sterilization, cooking and frying, freezing,
freezing–melting (or freeze concentration), microwave, ultrasound, ohmic heating, light, irradiation,
pulsed electric field, magnetic field, and high pressure. In addition, chapters on hurdle technology (or
combined methods) that uses a combination of preservation techniques are also included.
Part 5: Enhancing Food Preservation by Indirect Approach presents the approaches that indirectly help
food preservation by improving quality and safety. These techniques are packaging, hygienic design and
sanitation, hazard analysis and critical control point (HACCP), good manufacturing practice (GMP), and
commercial considerations of managing profit and quality. Packaging is an integral part of food preser-
vation and it has very wide scope. In this edition, packaging techniques are presented in three chapters.
This second edition will be an invaluable resource for practicing and research food technologists, engi-
neers, and scientists, and a valuable text for upper-level undergraduate and graduate students in food,
agriculture/biological science, and engineering. Writing a book is an endless process, so the editor would
appreciate receiving new information and comments to assist in future compilations. I am confident that
this edition will prove to be interesting, informative, and enlightening to readers.
Mohammad Shafiur Rahman
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page x
xi
Acknowledgments
I would like to thank Almighty Allah for giving me life and the opportunity to gain knowledge to write
this book. I wish to express my sincere gratitude to the Sultan Qaboos University for giving me the
opportunity and facilities to initiate such an exciting project, and supporting me toward my research and
other intellectual activities. I would also like to thank all my earlier employers, BUET, UNSW, and
HortResearch, from whom I built my knowledge and expertise through their support and resources. I
wish to express my appreciation to the UNSW, SQU, and HortResearch Library staffs, who assisted me
patiently with online literature searches and interlibrary loans.
I sincerely acknowledge the sacrifices made by my parents, Asadullah Mondal and Saleha Khatun,
during my early education. Appreciation is due to all my teachers, especially Professors Nooruddin
Ahmed, Iqbal Mahmud, Khaliqur Rahman, Jasim Zaman, Ken Buckle, Drs. Prakash Potluri and Robert
Driscoll, and Mr. Habibur Rahman, for their encouragement and help in all aspects of pursuing higher

education and research. I would like to express my appreciation to Professor Anton McLachlan, Drs.
Hamed Al-Oufi, Malik Mohammed Al-Wardy, and Salem Ali Al-Jabri for their support toward my teach-
ing, research, and extension activities at the Sultan Qaboos University. Special thanks to my colleagues
Dr. Conrad Perera, Professor Dong Chen, Drs. Nejib Guizani, Shyam Sablani, Bhesh Bhandari, and
Mushtaque Ahmed, and my other research team members, especially Mohd Hamad Al-Ruzeiki, Rashid
Hamed Al-Belushi, Mohd Khalfan Al-Khusaibi, Nasser Abdullah Al-Habsi, Insaaf Mohd Al-Marhubi,
and Intisar Mohd Al-Zakwani.
I wish to thank my relatives and friends, especially Professor Md. Mohar Ali Bepari and Dr. Md.
Moazzem Hossain, Dr. Iqbal Mujtaba, and Arshadul Haque for their continued inspiration. I am grateful
to my wife, Sabina Akhter (Shilpi), for her patience and support during this work, and to my little daugh-
ter, Rubaba Rahman (Deya), and son, Salman Rahman (Radhin), for allowing me to work at home and for
sharing their computer. Most of the work on this book was done at home; thus, without my family’s coop-
eration and support, it would have been very hard for me to complete and finalize this book.
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page xi
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page xii
xiii
Editor
Mohammad Shafiur Rahman is an associate professor at the Sultan Qaboos University, Sultanate of
Oman. He has authored or coauthored over 200 technical articles, including 70 refereed journal papers,
68 conference papers, 25 book chapters, 33 reports, 8 popular articles, and 3 books. He is also the author
of the internationally acclaimed and award-winning Food Properties Handbook, published by CRC
Press, Boca Raton, Florida, which was one of the bestsellers from CRC Press in 2002. The above book
is in the process of becoming a second edition. He was invited to serve as one of the associate editors for
the Handbook of Food Science, Engineering and Technology, and one of the editors for the Handbook of
Food and Bioprocess Modeling Techniques, which is being published by CRC Press. Dr. Rahman initi-
ated the publication of the International Journal of Food Properties (Marcel Dekker, Inc.) and is serving
as its founding editor for more than 9 years.
Dr. Rahman has served as a member in the Food Engineering Series Editorial Board of Aspen
Publishers, Maryland (1999–2003). In 2003 he was invited to serve as a member of the Food Engineering
Series Board, Kluwer Academic/Plenum Publishers, New York. He was also invited to serve as a section

editor for the Sultan Qaboos University Journal of Agricultural Sciences (1999). In 1998, he was invited
to serve as a food science adviser for the International Foundation for Science (IFS) in Sweden.
Dr. Rahman is a member of the New Zealand Institute of Food Science and Technology and the
Institute of Food Technologists, member of the American Society of Agricultural Engineers and the
American Institute of Chemical Engineers, and member of the Executive Committee for International
Society of Food Engineering (ISFE). He received his B.Sc. Eng. (Chemical) (1983) and M.Sc. Eng.
(Chemical) (1984) from Bangladesh University of Engineering and Technology, Dhaka; M.Sc. (1985) in
food engineering from Leeds University, England; and Ph.D. (1992) in food engineering from the
University of New South Wales, Sydney, Australia. Dr. Rahman has received numerous awards and
fellowships in recognition of his research/teaching achievements, including the
HortResearch Chairman’s
Award, the Bilateral Research Activities Program (BRAP) Award, CAMS Outstanding Researcher Award
2003, and the British Council Fellowship.
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page xiii
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page xiv
xv
Contributors
Jasim Ahmed Department of Food Science, McGill University, Ste Anne de Bellevue, Quebec, Canada
Mushtaque Ahmed College of Agricultural and Marine Sciences, Sultan Qaboos University, Muscat,
Sultanate of Oman
Saud M. Al-Jufaili Department of Marine Science and Fisheries, Sultan Qaboos University, Muscat,
Sultanate of Oman
Elizabeth A. Baldwin Citrus and Subtropical Products Laboratory, Agricultural Research Service,
U.S. Department of Agriculture, Winter Haven, Florida
Gustavo V. Barbosa-Canovas WSU Biological Systems Engineering, Center for Nonthermal
Processing of Foods, Washington State University, Pullman, Washington
Bhesh R. Bhandari School of Land and Food Sciences, The University of Queensland, St. Lucia,Australia
Titus De Silva Montana Wines Ltd., Auckland, New Zealand
Xiao Dong Chen Department of Chemical Engineering, Monash University, Victoria, Australia
Robert H. Driscoll Food Science and Technology Program, School of Chemical Sciences and

Engineering, The University of New South Wales, Sydney, Australia
T.V. Gamage Melbourne, Victoria, Australia
M. Marcela Gongora-Nieto Washington State University, Pullman, Washington
Leon G. M. Gorris European Chair in Food Safety Microbiology, Food Microbiology Laboratory,
Wageningen University, The Netherlands
Nejib Guizani Department of Food Science and Nutrition, College of Agricultural and Marine
Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman
Isam T. Kadim Department of Animal and Veterinary Sciences, Sultan Qaboos University, Muscat,
Sultanate of Oman
Gerard La Rooy Round Earth Business Process Improvement, Havelock North, New Zealand
Theodore P. Labuza Department of Food Science and Nutrition, University of Minnesota, St. Paul,
Minnesota
Yubin Lan USDA-ARS-SPARC-APMRU, College Station, Texas
Lothar Leistner Formerly, Director and Professor of the Institute of Microbiology, Toxicology and
Histology, Federal Centre for Meat Research, Kulmbach, Germany
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page xv
Marybeth Lima Department of Biological and Agricultural Engineering, Louisiana State University
Agricultural Center, Baton Rouge, Louisiana
Aurelio Lopez-Malo Chemical and Food Engineering Department, Universidad de las Americas-
Puebla, Sta. Catarina Martir, Cholula, Puebla, Mexico
Ajit K. Mahapatra Agricultural Research Station, Fort Valley State University, Fort Valley, Georgia
Osman Mahgoub Department of Animal and Veterinary Sciences, Sultan Qaboos University, Muscat,
Sultanate of Oman
Vijay Kumar Mishra Institute of Sustainability and Innovations and School of Molecular Sciences,
Victoria University, Melbourne, Victoria, Australia
Ann Mothershaw Department of Food Science and Nutrition, College of Agricultural and Marine
Sciences, Sultan Qaboos University, Sultanate of Oman
Linus U. Opara Agricultural Engineering and Postharvest Technology Program, College of
Agricultural and Marine Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman
Enrique Palou Chemical and Food Engineering Department, Universidad de las Americas-Puebla,

Sta. Catarina Martir, Cholula, Puebla, Mexico
Ronald B. Pegg Department of Food Science and Technology, The University of Georgia, Athens,
Georgia
Herman W. Peppelenbos Agrotechnology and Food Sciences Group, Wageningen University and
Research, The Netherlands
Anne Perera Fresh Direct Ltd., Auckland, New Zealand
Conrad O. Perera Department of Chemistry, The University of Auckland, Auckland, New Zealand
Jan Pokorny Department of Food Chemistry and Analysis, Faculty of Food and Biochemical
Technology, Prague Institute of Chemical Technology, Prague, Czech Republic
Mohammad Shafiur Rahman Department of Food Science and Nutrition, College of Agricultural
and Marine Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman
Hosahalli S. Ramaswamy Department of Food Science, McGill University, Ste Anne de Bellevue,
Quebec, Canada
M. N. Ramesh Department of Food Engineering, Central Food Technological Research Institute,
Mysore, India
Shyam S. Sablani Department of Food Science and Nutrition, College of Agricultural and Marine
Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman
Fereidoon Shahidi Department of Biochemistry, Memorial University of Newfoundland, St. John’s,
Newfoundland, Canada
Eddy J. Smid NIZO Food Research, Ede, The Netherlands
xvi Contributors
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page xvi
Barry G. Swanson Food and Nutrition Department, Washington State University, Pullman, Washington
P.J. Torley School of Land and Food Sciences, The University of Queensland, St Lucia, Queensland,
Australia
Humberto Vega-Mercado Washington State University, Pullman, Washington
Jorge F. Velez-Ruiz Chemical and Food Engineering Department, Universidad de las Americas-
Puebla, Cholula, Puebla, Mexico
Contributors xvii
CRC_DK3871_fm.qxd 6/14/2007 18:12 Page xvii

CRC_DK3871_fm.qxd 6/14/2007 18:12 Page xviii
Part 1
Preservation of
Fresh Food Products
CRC_DK3871_s001.qxd 4/21/2007 14:40 Page 1
CRC_DK3871_s001.qxd 4/21/2007 14:40 Page 2
1
Food Preservation: Overview
Mohammad Shafiur Rahman
CONTENTS
1.1 Introduction 3
1.2 What Are Foods? 4
1.3 Food Preservation 4
1.3.1 Why Preservation? 4
1.3.2 How Long to Preserve? 5
1.3.3 For Whom to Preserve? 5
1.4 Causes of Deterioration 6
1.5 Food Preservation Methods 8
1.5.1 Inhibition 9
1.5.2 Use of Chemicals 9
1.5.3 Controls of Water and Structure 11
1.5.4 Control of Atmosphere 12
1.5.5 Inactivation 12
1.5.5.1 Use of Heat Energy 12
1.5.5.2 Use of High Pressure and Ultrasound 13
1.5.5.3 Use of Electricity 13
1.5.5.4 Use of Radiation 13
1.5.5.5 Use of Magnetic Field 14
1.5.6 Avoid Recontamination (Indirect Approach) 14
1.6 Other Preservation Factors 15

References 17
1.1 Introduction
Food preservation involves the action taken to maintain foods with the desired properties or nature for as
long as possible. The process is now moving from an art to a highly interdisciplinary science. This chapter
provides an overview of food preservation methods with emphasis on inactivation, inhibition, and methods
of avoiding recontamination. The final section is a discussion of the factors that need to be considered to
satisfy present and future demands of the consumers and law-enforcing authorities.
In most countries, innovation, sustainability, and safety have become the main foci of modern indus-
try and economy. The United Nations World Commission on Environment and Development defined
sustainable development as “meeting the needs of the present generation without compromising the abil-
ity of future generations to meet their own needs.” A sustainable way of designing and developing food
products stands to appeal to consumers, and provides a point of differentiation from competitors and a
perfect platform for a range of positive public relations activities [6]. Innovation is vital to maintain
progress in technology and engineering. Food safety is now the first priority of the food production and
preservation industry, incorporating innovation and sustainability. The industry can compromise with
some quantities such as color to some extent, but not with safety.
3
CRC_DK3871_ch001.qxd 5/18/2007 16:41 Page 3
The preservation and processing of food is not as simple or straightforward as it was in the past. A
number of new preservation techniques are being developed to satisfy current demands of economic
preservation and consumer satisfaction in nutritional and sensory aspects, convenience, safety, absence
of chemical preservatives, price, and environmental safety. Understanding the effects of each preserva-
tion method on food has therefore become critical in all aspects. This chapter provides overviews of the
new technology, identifying the changing demands of food quality, convenience, and safety.
1.2 What Are Foods?
Foods are materials, raw, processed, or formulated, that are consumed orally by humans or animals for
growth, health, satisfaction, pleasure, and satisfying social needs. Generally, there is no limitation on the
amount of food that may be consumed (as there is for a drug in the form of dosage) [10]. This does not mean
that we can eat any food item as much as we want. Excessive amounts could be lethal, for example, salt, fat,
and sugar. Chemically, foods are mainly composed of water, lipids, fat, and carbohydrate with small

proportions of minerals and organic compounds. Minerals include salts and organic substances include vita-
mins, emulsifiers, acids, antioxidants, pigments, polyphenols, and flavor-producing compounds [19]. The
different classes of foods are perishable, nonperishable, harvested, fresh, minimally processed, preserved,
manufactured, formulated, primary, secondary derivatives, synthetic, functional, and medical foods [21]. The
preservation method is mainly based on the types of food that need to be prepared or formulated.
1.3 Food Preservation
Preservation methods start with the complete analysis and understanding of the whole food chain,
including growing, harvesting, processing, packaging, and distribution; thus an integrated approach
needs to be applied. It lies at the heart of food science and technology, and it is the main purpose of
food processing. First, it is important to identify the properties or characteristics that need to be pre-
served. One property may be important for one product, but detrimental for others. For example, col-
lapse and pore formation occur during the drying of foods. This can be desirable or undesirable
depending on the desired quality of the dried product, for example, crust formation is desirable for long
bowl life in the case of breakfast cereal ingredients, and quick rehydration is necessary (i.e., no crust
and more open pores) for instant soup ingredients. In another instance, the consumer expects apple juice
to be clear whereas orange juice could be cloudy.
1.3.1 Why Preservation?
Another important question is why food needs to be preserved. The main reasons for food preservation
are to overcome inappropriate planning in agriculture, produce value-added products, and provide vari-
ation in diet [20]. The agricultural industry produces raw food materials in different sectors. Inadequate
management or improper planning in agricultural production can be overcome by avoiding inappropri-
ate areas, times, and amounts of raw food materials as well as by increasing storage life using simple
methods of preservation. Value-added food products can give better-quality foods in terms of improved
nutritional, functional, convenience, and sensory properties. Consumer demand for healthier and more
convenient foods also affects the way food is preserved. Eating should be pleasurable to the consumer,
and not boring. People like to eat wide varieties of foods with different tastes and flavors. Variation in
the diet is important, particularly in underdeveloped countries to reduce reliance on a specific type of
grain (i.e., rice or wheat). In food preservation, the important points that need to be considered are
●
The desired level of quality

●
The preservation length
●
The group for whom the products are preserved
After storage of a preserved food for a certain period, one or more of its quality attributes may reach
an undesirable state. Quality is an illusive, ever-changing concept. In general, it is defined as the degree
4 Handbook of Food Preservation, Second Edition
CRC_DK3871_ch001.qxd 5/18/2007 16:41 Page 4
of fitness for use or the condition indicated by the satisfaction level of consumers. When food has dete-
riorated to such an extent that it is considered unsuitable for consumption, it is said to have reached the
end of its shelf life. In studying the shelf life of foods, it is important to measure the rate of change of a
given quality attribute [25]. In all cases, safety is the first attribute, followed by other quality. The prod-
uct quality attributes can be quite varied, such as appearance, sensory, or microbial characteristics. Loss
of quality is highly dependent on types of food and composition, formulation (for manufactured foods),
packaging, and storage conditions [25]. Quality loss can be minimized at any stage of food harvesting,
processing, distribution, and storage. When preservation fails, the consequences range broadly from
minor deterioration, such as color loss, to food becoming extremely hazardous [8].
1.3.2 How Long to Preserve?
After storage for a certain period, one or more quality attributes of a food may reach an undesirable state.
At that time, the food is considered unsuitable for consumption and is said to have reached the end of its
shelf life. This level is defined by the manufacturer according to criteria when the product is saleable. Best-
before date is set shorter than the shelf life with a good margin. Hence, it is usually safe and palatable to
consume a product a long time after the best-before date, provided the product has been stored at the rec-
ommended conditions. Products may be marketed with the production date “pack date” and “best-before
date.” Alternative markings are use-by date or expiration date, which may be closer to shelf life than best-
before date [1]. In studying the shelf life of foods, it is important to measure the rate of change of a given
quality attribute [25]. The product quality can be defined using many factors, including appearance, yield,
eating characteristics, and microbial characteristics, but ultimately the final use must provide a pleasurable
experience for the consumer [23]. The various stages of food production, manufacture, storage, distribution,
and sale are shown in Figure 1.1. Quality

loss can be minimized at any stage and
thus quality depends on the overall con-
trol of the processing chain. The major
quality-loss mechanisms and conse-
quences are shown in Table 1.1 and
Figure 1.2. The required length of preser-
vation depends on the purpose. In many
cases, very prolonged storage or shelf life
is not needed, which simplifies both the
transport and marketing of the foodstuff.
For example, the meals prepared for
lunch need a shelf life of only one or even
half a day. In this case, there is no point in
ensuring preservation of the product for
weeks or months. In other cases, very
long shelf life up to 3–5 years may be
required, for example, foods for space
travelers and food storage during wars.
1.3.3 For Whom to Preserve?
It is important to know for whom the
preserved food is being produced.
Nutritional requirements and food
restrictions apply differently to different
population groups. Food poisoning can
be fatal, especially in infants, pregnant
women, the elderly, and those with
depressed immune systems. The legal
aspects of food preservation are different
Food Preservation: Overview 5
Harvesting

Storage
Fresh foods
Food
ingredients
Processing
Packaging
Storage
Distribution
Sale
Transport
Storage
Consumption
Food
processors
Consumers
FIGURE 1.1 Various stages of food production, manufacture, storage,
distribution, and sale.
CRC_DK3871_ch001.qxd 5/18/2007 16:41 Page 5
in case of foods produced for human and for animal consumption. Thus, it is necessary to consider the
group for whom the products are being manufactured.
1.4 Causes of Deterioration
Mechanical, physical, chemical, and microbial effects are the leading causes of food deterioration and
spoilage. Damage can start at the initial point by mishandling of foods during harvesting, processing,
and distribution; this may lead to ultimate reduction of shelf life. Other examples of deterioration can be
listed as follows: (i) bruising of fruits and vegetables during harvesting and postharvest handing, leading to
the development of rot, (ii) tuberous and leafy vegetables lose water when kept in atmospheres with low
humidity and, subsequently, wilt, and (iii) dried foods kept in high humidity may pick up moisture and
become soggy. The four sources of microbial contaminants are soil, water, air, and animals (insects, rodents,
and humans) (Table 1.2). The major causes of quality loss are shown in Table 1.1. In preservation, each
6 Handbook of Food Preservation, Second Edition

Quality
Safety
• Advertisement
• Public knowledge
• Social factor
• Economic factor
• Consumer age
• Media report
• Past experience
• Attitude
• Expectation
• Sensory
• Nutritive
• Functional
• Convenience
• Level of micro-flora
• Pathogens
• Microbial toxins
• Parasites
• Toxic chemicals
• Radioactive hazards
Unsafe
Food properties
Emotional factors
Choice
FIGURE 1.2 Factors affecting food quality, safety, and choice.
TABLE 1.1
Major Quality-Loss Mechanisms
Microbiological Enzymatic Chemical Physical Mechanical
Microorganism Browning Color loss Collapse Bruising due to

growth vibration
Off-flavor Color
change Flavor loss Controlled release Cracking
Toxin production Off-flavor Nonenzymatic Crystallization Damage due to
browning pressure
Nutrient loss Flavor encapsulation
Oxidation–reduction Phase changes
Rancidity Recrystallization
Shrinkage
Transport of
component
Source: Gould, G. W. 1989. In: Mechanisms of Action of Food Preservation Procedures. Gould, G. W., Ed. Elsevier Applied
Science, London; Gould, G. W. 1995. In: New Methods of Food Preservation. Gould, G. W., Ed. Blackie Academic and
Professional, Glasgow.
CRC_DK3871_ch001.qxd 5/18/2007 16:41 Page 6