Electromagnetic Radiations in Food Science

253 Pages·1992·7.19 MB·English

by  Ionel Rosenthal Ph.D. (auth.)

Advanced Series in Agricultural Sciences 19
Co-ordinating Editor: B. Yaron, Bet-Dagan
Editors: G.W. Thomas, Lexington
L.D. Van Vleck, Ithaca
Advanced Series in Agricultural Sciences
Volumes already published in the series
Volume 1: A.P.A. Vink
Land Use in Advancing Agriculture
Volume 2: H. Wheeler
Plant Pathogenesis
Volume 3: R.A.Robinson
Plant Pathosystems
Volume 4: H. C. Cappel, J. W. Mertins
Biological Insect Pest Suppression
Volume 5: J.J.Hanan, W. D.Holley, K. L. Goldsberry
Greenhouse Management
Volume 6: f.E. Vanderplank
Genetic and Molecular Basis of Plant Pathogenesis
Volume 7: J. K. Matsushima
Feeding Beef Cattle
Volume 8: R.J.Hanks, G.L.Ashcroft
Applied Soil Physics
Volume 9: J. Palti
Cultural Practices and Infectious Crop Diseases
Volume 10: E. Bresler, B. L. McNeal, D. L. Carter
Saline and Sodic Soils
Volume 11: f.R.Parks
A Theory of Feeding and Growth of Animals
Volume 12: J.Hagin, B. Tucker
Fertilization of Dryland and Irrigated Soils
Volume 13: A.f. Koolen, H. Kuipers
Agricultural Soil Mechanics
Volume 14: G. Stanhill
Energy and Agriculture
Volume 15: E.A.Curl, B. Truelove
The Rhizosphere
Volume 16: D. P. Doolittle
Population Genetics: Basic Principles
Volume 17: A. Feigin, I. Ravina, J. Shalhevet
Irrigation with Treated Sewage Effluent
Volume 18: D. Gianola, K. Hammond
Advances in Statistical Methods for Genetic Improvement of Livestock
Volume 19: I. Rosenthal
Electromagnetic Radiations in Food Science
1. Rosenthal
Electromagnetic Radiations
in Food Science
With 28 Figures and 26 Tables
Springer-Verlag
Berlin Heidelberg New York
London Paris Tokyo
Hong Kong Barcelona
Budapest
lonel Rosenthal, Ph.D.
Department of Food Science
Agricultural Research Organization, The Volcani Center
P.O. Box 6, Bet Dagan 50250, Israel
ISBN-13: 978-3-642-77108-8 e-ISBN-3: 978-3-642-77106-4
DOl: 10.1007/978-3-642-77106-4
Library of Congress Cataloging-in-Publication Data
Rosenthal, Ionel. Electromagnetic radiations in food science/I. Rosenthal. - (Advanced series
in agricultural sciences; 19) Includes bibliographical references and index. ISBN 3-540-54833-5
(Berlin) - ISBN 0-387-54833-5 (New York) I. Radiation preservation of food. 2. Electro
magnetic waves. I. Title. II. Series. TP371.8. R67 1992 664' .0288-dc20
This work is subject to copyright. All rights are reserved, whether the whole or part of the
material is concerned, specifically the rights of translation, reprinting, reuse of illustrations,
recitation, broadcasting, reproduction on microfilms or in other ways, and storage in data
banks. Duplication of this publication or parts thereof is only permitted under the provisions of
the German Copyright Law of September 9, 1965, in its current version, and a copyright fee
must always be paid.
© Springer-Verlag Berlin Heidelberg 1992
Sof'tcover reprint of the hardcover 1s t edition 1992
The use of registered names, trademarks, etc. in this publication does not imply, even in the
absence of a specific statement, that such names are exempt from the relevant protective laws
and regulations and therefore free for general use.
Typesetting: Best-Set Typesetter Ltd., Hong Kong
31/3145-5 4 3 2 I 0 - Printed on acid-free paper
Preface
This book has been written for those whose interests bridge food
processing and physicochemical aspects of radiation. It is not
intended to be a comprehensive review of publications concerning
foods and radiations. Instead, it is an attempt to familiarize the
reader with pertinent knowledge of a unified, interdisciplinary
concept of various electromagnetic radiations and corresponding
effects on foods. Consideration was given to similarities and differ
ences between various segments of the electromagnetic spectrum.
The broad approach of this book was considered to be crucial for
cross-discipline comparisons.
The reader is introduced to the electromagnetic spectrum in
the Prologue and then the book follows the wavelengths, from
short to long values. Chapter 1 deals with ionizing radiation:
historical background, sources of radiation employed in food
treatment, units of measurement, and fundamentals of radiation
chemistry. A survey of potential applications of ionizing radiation
in food technology is followed by a description of methods for
radiation dosimetry. Safety and wholesomeness of irradiated foods,
analytical methods for postirradiation dosimetry in foods, and
consumer acceptance of food irradiation conclude this section.
Chapter 2 intrudes into the next segment of the spectrum: ultra
violet-visible radiation. The general presentation of this electro
magnetic emission and illumination source enables the discussion
of its effects on foods, including applications in food analysis.
Chapter 3 covers infrared heating and analytical applications of
infrared radiation. Microwave radiation is the topic of Chapter 4:
molecular mechanisms of heating with microwaves, equipment and
applications in the food industry are discussed. Chapter 5 covers
two case studies which exemplify the practical potential of ionizing
radiation in food treatment: suppression of postharvest pathogens
of fresh fruits and vegetables, and decontamination of poultry
meat. Both of these topics deal with the interaction between
microorganisms and food.
It goes without saying that a book like this cannot be written on
the exclusive basis of personal observations. Reading what others
have written has been a salient source of information and the
VI Preface
greatest debt is owed to the many researchers whose detailed
observations made this volume possible. References are gathered
at the end of the book. Unreviewed and less widely available
publications have been avoided as much as possible.
The content of the book recalls the many pleasant associations
which the author has had with people and research projects in the
fields of radiations and food chemistry. The contributions by Drs.
Moshe Faraggi, Rivka Barkai-Golan, I. Klinger and M. Lapidot
are most appreciated. I also thank Mrs. S. Bernstein for so ably
preparing the manuscript for the press.
In closing, let me acknowledge some of those who have con
tributed indirectly, though not insubstantially, to the success of this
project. Haya, my partner through life, and Tal, Shirrie and Dana
have shown interest, patience, and concern both through the
"highs" and "lows" of this project.
Bet Dagan, Israel, October 1992 lonel Rosenthal
Contents
Prologue Electromagnetic Radiation. . . . . . . . . . . . . . . . . . . 1
Chapter 1 Ionizing Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1 Sources and Units of Measurement of Ionizing Radiation 9
1.1.1 Sources of Ionizing Radiation . . . . . . . . . . . . . . . . . . . 9
1.1.2 Units of Measurement ......................... 11
1.2 Interaction of Ionizing Radiation with Matter.
Chemistry of Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
1.2.1 Interaction of Ionizing Radiation with Matter ..... 12
1.2.2 Radiation Chemistry. . . . . . . . . . . . . . . . . . . . . . . . . .. 17
1.3 Applications of Ionizing Radiation in Food Technology .. 20
1.4 Radiation Dosimetry (M. Faraggi) .................... 32
1.4.1 Physical Dosimetric Methods. . . . . . . . . . . . . . . . . . .. 32
1.4.2 Chemical Dosimetric Methods .................. 33
1.5 Safety and Wholesomeness of Irradiated Foods. . . . . . . .. 36
1.6 Analytical Methods for Postirradiation Dosimetry
of Foods ........................................... 40
1.6.1 Measurements of Physical Effects. . . . . . . . . . . . . . .. 55
1.6.2 Measurements of Chemical Effects. . . . . . . . . . . . . .. 58
1.6.3 Microbiological and Biological Methods . . . . . . . . .. 61
1.6.4 Conclusions .................................. 62
1.7 Consumer Acceptance of Food Irradiation. . . . . . . . . . . .. 63
Chapter 2 Ultraviolet-Visible Radiation. . . . . . . . . . . . . . . .. 65
2.1 The Definition of Ultraviolet-Visible Radiation . . . . . . . .. 65
2.2 Interactions Between Ultraviolet-Visible Radiation
and Matter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 66
2.2.1 Absorption and Emission of Light ....... . . . . . . .. 66
2.2.2 Polarized Light. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 72
2.3 Photooxidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 72
2.4 Illumination Sources and Units of Measurement ........ 77
2.4.1 Illumination Sources. . . . . . . . . . . . . . . . . . . . . . . . . .. 77
VIII Contents
2.4.2 Units of Measurement ......................... 79
2.5 Biological Effects and Safety Aspects
of Ultraviolet-Visible Radiation. . . . . . . . . . . . . . . . . . . . . .. 79
2.6 Effects of Ultraviolet-Visible Radiation on Foods ....... 81
2.6.1 The Color of Foods. . . . . . . . . . . . . . . . . . . . . . . . . . .. 81
2.6.2 Beneficial Effects of Light in Production of Foods.. 83
2.6.3 Photodegradation of Foods .... . . . . . . . . . . . . . . . .. 88
2.6.4 Light Absorbers and Photoinitiators in Foods ..... 89
2.6.5 Constituents of Foods Sensitive
to Photodegradation . . . . . . . . . . . . . . . . . . . . . . . . . .. 90
2.7 Applications of Ultraviolet-Visible Radiation
in Food Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 101
Chapter 3 Infrared Radiation . . . . . . . . . . . . . . . . . . . . . . . . .. 105
3.1 The Definition of Infrared Radiation .................. 105
3.2 Sources of Infrared Radiation ........................ 106
3.3 Infrared Heating in Food Processing ................... 107
3.4 Analytical Applications of Infrared Radiation ........... 112
Chapter 4 Microwave Radiation. . . . . . . . . . . . . . . . . . . . . . .. 115
4.1 The Definition of Microwave Radiation. . . . . . . . . . . . . . .. 115
4.2 Molecular Mechanisms of Heating with Microwaves . . . .. 115
4.3 Equipment for Microwave Heating. . . . . . . . . . . . . . . . . . .. 126
4.4 Applications of Microwave Heating in the Food Industry 129
4.5 Materials for Food Containers for Microwave Treatment 145
4.6 Safety Aspects of Microwave Heating Equipment ....... 147
4.7 Analytical Applications of Microwave Radiation ........ 149
Chapter 5 Case Studies ............................... 155
5.1 Suppression of Postharvest Pathogens of Fresh Fruits
and Vegetables by Ionizing Radiation (R. Barkai-Golan) 155
5.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 155
5.1.2 Radiation Effects on Pathogens ................. 156
5.1.3 Radiation Effects on Disease Development ....... 167
5.1.4 Pathological and Microbiological Problems
Following Irradiation .......................... 189
5.1.5 Conclusions .................................. 192
5.2 Decontamination of Poultry Meat by Ionizing Radiation
(1. Klinger and M. Lapidot) . . . . . . . . . . . . . . . . . . . . . . . . .. 194
5.2.1 Microbiological Quality of Processed Poultry Meat 194
5.2.2 Pathogenic Bacterial Contaminants
of Poultry Meat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 196
Contents IX
5.2.3 Decontamination of Poultry Meat
by Ionizing Radiation . . . . . . . . . . . . . . . . . . . . . . . . .. 201
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 209
Prologue
Electromagnetic Radiation
Electromagnetic radiation can be regarded as having a dual nature. From
the time of Newton until the advent of the quantum theory, the pre
dominant apprehension of electomagnetism was the wave theory. The
propagation phenomena such as reflection, refraction, diffraction, polariz
ation and, particularly, interference can be explained in terms of propagation
of a wave. However, the actual nature of the wave and the mechanism of
its propagation were not established until the latter part of the nineteenth
century. In the 1860s James Clerk Maxwell made one of the major con
tributions to physics. He demonstrated by powerful mathematical reasoning
that an oscillating magnetic field was associated with a similar electric field,
if a wave was propagated in a direction perpendicular to a plane containing
these fields. Maxwell's equations indicated that the velocity of propagation
of an "electromagnetic" wave in vacuo is numerically identical to the
velocity of light. In 1887 Hertz confirmed Maxwell's prediction of propa
gated waves from systems involving oscillating electrical and magnetic
fields.
Maxwell's electromagnetic field theory describes radiation in terms of
oscillating electric (E) and magnetic (H) fields operating in planes which are
perpendicular to each other and to the direction of progress. The time
variable strength of the resulting vector is described as a transverse wave by
a sinusoidal function (Fig. 1).
Fig. 1. A wave of electromagnetic radiation