Food Irradiation Research and Technology

Christopher H. Sommers, Ph.D., a research microbiologist and lead scientist, and Xuetong Fan, Ph.D., a research food technologist, both work for the Food Safety Intervention Technologies Research Unit, USDA-ARS-Eastern Regional Research Center, Wyndmoor, PA. Drs. Sommers and Fan were co-moderators of the IFT symposium from which this book arose and have over thirty years combined experience in food irradiation, food technology, chemistry, microbiology and toxicology.

• List of Contributors xixPreface xxvChapter 1 Introduction: Food Irradiation Moving On 1Joseph BorsaIntroduction 2Two Tracks Going Forward 3The Food Safety Track 3The Disinfestation Track 5Bumps Still Remain on the Road Ahead 5Summary 7References 7Chapter 2 Advances in Electron Beam and X-ray Technologies for Food Irradiation 9Marshall R. ClelandIntroduction 10Basic Irradiation Concepts 10Definition and Units of Absorbed Dose 10Absorbed Dose versus Emitted Radiation Power 11Temperature Rise versus Dose 12Electron Beam Facilities 13Absorbed Dose versus Beam Current 14Electron Beam Technologies 14X-ray Facilities 21Conclusion 24References 25Chapter 3 Gamma Ray Technology for Food Irradiation 29Kevin O’HaraIntroduction 29Overview of Co-60 Gamma Technology 30Basic Irradiation Concepts 32Gamma Ray Facilities 32Irradiator Categories 34Criteria for Irradiator Design and Selection 35Pallet Irradiator 38Tote Box Irradiator 40Independent Dose Delivery Carrier and Stationary Irradiations 41Gray∗ Star GenesisTM Underwater Irradiator 42Gamma Ray Facilities for Radiation Research 43Comparison of Irradiation Technologies 45References 46Chapter 4 Regulation of Irradiated Foods and Packaging 47George H. PauliIntroduction 48References 52Notes 52Chapter 5 Toxicological Safety of Irradiated Foods 53Christopher H. Sommers, Henry Delincee, J. Scott Smith, and Eric MarchioniIntroduction 54Food Irradiation 54Benzene, Formaldehyde, and Amines 56Formation and Levels of 2-ACBs in Foods 57Toxicological Safety of 2-ACBs 632-ACBs and Tumor Promotion 66Diet and Tumor Promotion 67Conclusions 67References 68Chapter 6 Radiation Chemistry of Food Components 75Xuetong FanBasic Radiation Effects 76Radiolysis of Water 76Radiation Chemistry of Major Food Components 77Radiation Chemistry of Lipids 77Radiolysis of Proteins 80Radiolysis of Carbohydrates 83Reduction of Undesirable Compounds by Irradiation 88Reduction of Furan and Acrylamide 88Reduction of Mycotoxins 89Antinutritional Compounds 92Acknowledgments 93References 93Chapter 7 Dosimetry for Food Processing and Research Applications 99Kishor Mehta and Kevin O’HaraImportance of Dosimetry 99Introduction 100Some Fundamentals of Dosimetry 101Absorbed Dose 101Dosimetry System 102Measurement Management System 103Selection and Characterization of a Dosimetry System 103Types of Dosimetry Systems 103The Selection of an Appropriate Dosimetry System 104Dosimetry System Characterization 106The Use of a Dosimetry System 107Dosimetry in Food Research 108Dosimetry at a Commercial Facility 109General 109Process Validation 110Operational Qualification (OQ) 110Performance Qualification (PQ) 114Routine Process Monitoring and Control 117References 120Chapter 8 Detection of Irradiated Foods 123Eric MarchioniIntroduction 124Free Radicals and Electronic Excited States 126ESR Spectroscopy 126Luminescence 129Stable Radiolytic Products 131Radiolytic Products from Proteins 131Volatile Compounds 131Radiolytic Products from Carbohydrates 132Radiolytic Products from Nucleic Acids 132Radiolytic Products from Lipids 134Modification of Macroscopic Physico-Biological Parameters of the Food 137Gas Evolution 138Cellular Wall Modifications 138Bacteriological Modifications 138Germination Inhibition 139Irradiated Ingredients and Low-Dose Irradiated Plants 139Conclusion 140References 140Chapter 9 Irradiation of Packaging Materials in Contact with Food: An Update 147Vanee KomolprasertIntroduction 148Current Authorizations of Packaging Materials for Irradiation of Prepackaged Food 149Radiation-Induced Chemical Changes in Packaging Materials 157Role of AOs 158Evaluating Packaging Materials Irradiated in the Presence of Oxygen 159Irradiation Effects 160Analysis for RPs 161Dietary Exposure to RPs 162Safety Assessment of RPs 164Approaches to Testing 165Conclusions 167Acknowledgment 168References 168Chapter 10 Consumer Acceptance and Marketing of Irradiated Foods 173Ronald F. Eustice and Christine M. BruhnIntroduction 174What Is Food Irradiation? 174Why Is Food Irradiated? 174Marketing of Irradiation Foods 176Commercial Acceptance of Irradiation Foods 177Resistance to “New” Technology 178Risks versus Benefits 179World’s Safest Food Supply, But Not Safe Enough 179Irradiation: A Powerful and Effective Tool to Improve Food Safety 181Education: The Key to Consumer Acceptance 182Effect of Unfavorable Information 185Can Unfavorable Information Be Counteracted? 186Effects of Gender, Income, and Children 188Barriers to Acceptance 188The “Minnesota Model” of Consumer Acceptance 189A Defining Moment in Food Safety 191Is It Farm to Fork, or Turf to Tort? 192Conclusion 192References 193Chapter 11 Irradiation of Ready-To-Eat Meat Products 197Christopher H. Sommers and William J. MackayIntroduction 198Materials and Methods 198RTE Meats 198Processing of Beef Bologna 199Bacterial Isolates 199Preparation of Inoculum 200Inoculation of RTE Meats 200Gamma Irradiation 200Enumeration of Bacteria 201Storage Study 201D10 Values 201Statistical Analysis 202Results and Discussion 202Acknowledgment 205References 205Chapter 12 Mechanisms and Prevention of Quality Changes in Meat by Irradiation 209Doug U. Ahn and Eun Joo LeeIntroduction 209Food Irradiation 210Microcidal Effect 211Quality Changes in Meat by Irradiation 213Lipid Oxidation 213Sources and Mechanisms of Off-Odor Production 214Color Changes in Meat by Irradiation 216Control of Off-Odor Production and Color Changes 220Additives 220Packaging 221Packaging and Additive Combinations 221Future Research 222References 222Chapter 13 Phytosanitary Irradiation for Fresh Horticultural Commodities: Research and Regulations 227Peter A. Follett and Robert L. GriffinIntroduction 228Developing Irradiation Quarantine Treatments 228Insect Radiotolerance 228Methodology 231Varietal Testing 234Probit 9 Efficacy and Alternatives 234Generic Radiation Treatments 236Regulatory Aspects of Irradiation 240USDA Regulations 242Regional and International Harmonization 244Trade 245References 249Chapter 14 Antimicrobial Application of Low-Dose Irradiation of Fresh and Fresh-Cut Produce 255Brendan A. NiemiraIntroduction 256Produce Microbiology and Irradiation Treatment 257Internalization of Bacteria 258Biofilm-Associated Pathogens 260Postirradiation Recovery and Regrowth 261Treatment Parameters for Irradiation of Produce 262Influence of Plant Variety 264Combination with Sanitizers 264Irradiation Plus Mild Thermal Treatment 265Summary 266Acknowledgments 266References 266Chapter 15 Irradiation of Fresh and Fresh-Cut Fruits and Vegetables: Quality and Shelf Life 271Xuetong FanIntroduction 272Ethylene and Respiration 273Appearance 274Texture 276Flavor/Taste 278Nutrients 281Vitamin C 281Other Nutrients 282Combination of Irradiation with Other Postharvest Techniques 284Chemical Sanitizers 284Hot-Water Treatment 284Calcium and Calcium Ascorbate 285MAP 286Shelf-Life Extension 287References 288Chapter 16 Irradiation of Seeds and Sprouts 295Kathleen T. Rajkowski and Md. Latiful BariIntroduction 295Outbreaks Associated with Sprouts 296Potential Source of Contamination 301Pathogens of Concern for Sprouts 302Salmonella 302Enterohemorrhagic E. coli 302L. monocytogenes 302B. cereus 303Yersinia enterocolitica 303Shigella 303Klebsiella 303Pathogen Decontamination Overview 304Seed and Sprout Evaluation after Treatment 305Radiation Dose to Reduce Microbial Pathogens on Seeds 305Combination Treatments 308Radiation Dose to Reduce Microbial Pathogens on Sprouts 308Other 309Conclusions 310References 310Chapter 17 Irradiation of Nuts 317Anuradha PrakashIntroduction 317Farming and Harvesting 318Insect Disinfestation 318Microbial Contamination 319Contamination with Pathogens 320Irradiation Treatment of Nuts 323Insect Disinfestation 323Molds and Aflatoxins 324Pathogen Inactivation 325Chemical and Sensory: Irradiation Can Catalyze or Induce Lipid Peroxidation, and Lipid and/or Protein Radiolysis 325Nonoxidative Radiolytic Reactions 329Effect of Irradiation on Nut Allergenicity 329Advantages of Using Irradiation to Treat Nuts 330Research Needs 330References 331Chapter 18 Irradiation of Seafood with a Particular Emphasis on Listeria monocytogenes in Ready-To-Eat Products 337Denise M. FoleyIntroduction 338Listeria monocytogenes Is a Significant Contaminant of Seafood 338Stress Adaptation of the Organism 339Irradiation Is an Effective Postprocessing Treatment for Fish Products 340Physical, Chemical, and Sensory Changes of Irradiated Seafood 344Competing Microflora 345Comments Regarding Irradiation and the Risk for Botulism 346Conclusion 346References 346Chapter 19 Ionizing Radiation of Eggs 351Ignacio Alvarez, Brendan A. Niemira, Xuetong Fan, and Christopher H. SommersIntroduction 352Ionizing Radiation of Shell Eggs 353Microbial Lethal Effect of Ionizing Radiation on Shell Eggs 353Internal Quality of Ionizing Radiated Shell Eggs 356Physicochemical Properties of Ionizing Radiated Shell Eggs 358Functional Properties of Ionizing Radiated Shell Eggs 358Ionizing Radiation of Refrigerated Liquid Egg 359Ionizing Radiation of LWE 359Ionizing Radiation of Liquid Egg White 361Ionizing Radiation of Liquid Egg Yolk 362Ionizing Radiation of Dried Egg 363Microbial Lethal Effect of Ionizing Radiation in Dried Egg 363Quality of Ionizing Radiated Dried Egg 363Physicochemical Properties of Ionizing Radiated Dried Egg 363Functional Properties of Ionizing Radiated Dried Egg 364Ionizing Radiation of Frozen Egg 365Microbial Lethal Effect of Ionizing Radiation in Frozen Egg 365Physicochemical Properties of Ionizing Radiated Frozen Egg 365Functional Properties of Ionizing Radiated Frozen Egg 365Strategies to Increase the Quality of Irradiated Egg Products 366Areas for Future Research 368Conclusion 369Acknowledgments 370References 370Chapter 20 Irradiated Ground Beef for the National School Lunch Program 373Xuetong FanIntroduction 374Foodborne Illnesses in School 374Regulatory Allowance and Specifications of Irradiated Foods for Schools 376Sensory Properties of Irradiated Ground Beef 378Conclusion 382Acknowledgments 383References 383Chapter 21 Potential Applications of Ionizing Radiation 385Ju-Woon Lee, Jae-Hun Kim, Yohan Yoon, Cheorun Jo, and Myung-Woo ByunIntroduction 386Reduction of Food Allergies by Ionizing Radiation 386Volatile N-nitrosamine and Residual Nitrite Reduction 387Biogenic Amines Reduction 390Reduction of Phytic Acid and Increase in Antioxidant Activity 391Chlorophyll b Breakdown 393Color Improvement of Plant Extracts without Change of Biological Functions 393Control of Enterobacter sakazakii in Infant Formula 394Use of Irradiation to Control Food-Related Bacteria in Meat Products 394Application of Irradiation for Sea Food Safety 396Use of Irradiation on Fresh Produces and Dairy Products 396Application of Irradiation for the Development of Traditional Fermented Foods 397Use of Boiled Extracts from Cooking 398Improvement of Nutritional Conditions and Food Quality by Irradiation 399Conclusion 399Acknowledgments 399References 400Chapter 22 A Future Uncertain: Food Irradiation From a Legal Perspective 407Denis W. StearnsIntroduction 408Liability for the Manufacture of a Defective Food Product 409The Origins of Strict Liability in Tainted Food Cases 409The Modern Rule of Strict Liability 410Defining Products and Defects 410Proving the Existence of a Defect in Food 411Strict Liability Creates Few If Any Legal Incentives in Favor of Food Irradiation 412A Possible Existing Legal Duty to Use Irradiated Food: The Challenge of Highly Susceptible Populations 414Negligence: Failing to Avoid a Known and Avoidable Risk 414The Eggshell Plaintiff: Irradiation, Liability, and Susceptible Populations 416The Prospect of Punitive Damages as a Stronger Incentive 417The Possibility of Liability Arising from Irradiated Foods 418Conclusion 419Notes 420Chapter 23 Technical Challenges and Research Directions in Electronic Food Pasteurization 425Suresh D. Pillai, Les Braby, and Joe MaximIntroduction 426Target Pathogens 427Enteric Viruses 427Protozoan Pathogens 428Bacterial Pathogens 428Radiation Physics and Chemistry 428Chemical Environment 428Standardized Protocols 429Electronic Pasteurization in Conjunction with Microbial Risk Assessment 430Low Dose Electronic Pasteurization and Dosimetry 431Product Packaging 431Electronic Pasteurization of Complex-Shaped Packages 432Acknowledgments 433References 433Index 435