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FOOD IRRADIATION
Maria del Pilar Solano, M.D. April 29, 2003
What is Food Irradiation ?
“Process by which food is exposed to a controlled source of ionizing radiation to prolong shelf life, improve microbiologic safety, and/or reduce the use of chemical fumigants and additives”
Food Irradiation Uses
• Reduce insect infestation -grain, spices, fruits and vegetables
• Inhibit sprouting -tubers and bulbs
• Retard ripening -fruits
• Inactivate parasites -meats and fish
• Eliminate spoilage microbes -fruits, veggies
• Extend shelf life -poultry, meat, fish, shellfish
• Decontaminate -poultry and meat
• Sterilize foods and feeds
ListeriaToxoplasmaHepatitis A
SalmonellaCriptosporidiumE.coli. Shiguella Emer Inf Dis 1999;5: 786
FOOD-BORNE ILLNESS
Irradiation Sources:•Gamma rays (cobalt 60 or Cesium 137)•Electron-beam•X ray
Dose for food irradiation: 0.05-10 kGy
Food Irradiation-Regulation
• 1958: Food Additives Amendment to the Federal Food, Drug and Cosmetic Act of 1938
Food Dose (KGy) Purpose Approval year
Wheat flour 0.2-0.5 Control of mold 1963
White potatoes 0.05-0.15 Inhibit sprouting 1964
Pork 0.3-1.0 Kill Trichina parasites 1986
Fruit and vegetables
1.0 Insect control, increase shelf-life 1986
Herbs and spices 30 Sterilization 1986
Poultry 3.0 Bacterial pathogen reduction 1990-FDA
Poultry 1.5-3.0 Bacterial pathogen reduction 1992-USDA
Meat 4.5 (fresh)-7(frozen)
Bacterial pathogen reduction 1997-FDA
Meat 4.5 Bacterial pathogen reduction 1999-USDA
Fresh shell eggs 3.0 Control Salmonella species 2000
Food Irradiation - Safety
• Radiologic and toxicologic safety:- Neither the food nor the packaging become
radioactive- No concern for unique radiolytic products (FDA)- Animal feeding studies since 1950 with metabolic,
reproductive, teratogenic, mutageic endpoints. FAO, WHO, FDA food irradiation is safe under specified conditions
Food Irradiation-Safety
• Microbiological Safety
Microbiologic safety
• Viruses, spores, prions are resistant to radiation
• Gram(-)spoilage bacteria > suceptible than pathogenic bacteria
• Clostridium botulinun type E is resistant
• ? Increase in mycotoxin after irradiation
• ? Radiation resistance and mutational changes
Nutritional Adequacy
• Changes similar to those of cooking, canning, pausteurizing, heat processing
• Vitamin loss: Thiamine>Vit C, B6>B2>niacin. Synergism with heat
• CHO and proteins relatively irradiation-resistant
• Fats can be oxidized rancidity, odor changes
Consumer Issues
Controversies
• Safety: ?Chromosome damage in susceptible individuals. ?long-term effects
• Nutrition: ? Effect of Vitamin loss in elderly, malnourished and children
• Environmental: ?danger of transporting radioactive isotopes, new irradiation plants, worker exposure
The Future ?