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

FOOD-BORNE ILLNESS Listeria Toxoplasma Hepatitis A Salmonella Criptosporidium E.coli. Shiguella Emer Inf Dis 1999;5: 786

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 Herbs and spices 30 Sterilization Poultry 3.0 Bacterial pathogen reduction 1990-FDA 1.5-3.0 1992-USDA Meat 4.5 (fresh)-7(frozen) 1997-FDA 4.5 1999-USDA Fresh shell eggs 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 ?