ebook img

Electromagnetic Radiations in Food Science PDF

253 Pages·1992·7.19 MB·English
Save to my drive
Quick download
Download
Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.

Preview Electromagnetic Radiations in Food Science

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

See more

The list of books you might like

Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.