1. FOOD IRRADIATION
Maria del Pilar Solano, M.D.
April 29, 2003

2. 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”

3. 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

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

5. Irradiation Sources:
Gamma rays (cobalt 60 or Cesium 137)
Electron-beam
X ray
Dose for food irradiation: kGy

6. Food Irradiation-Regulation
1958: Food Additives Amendment to the Federal Food, Drug and Cosmetic Act of 1938

7. Food
Dose (KGy)
Purpose
Approval year
Wheat flour
Control of mold
1963
White potatoes
Inhibit sprouting
1964
Pork
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
1992-USDA
Meat
4.5 (fresh)-7(frozen)
1997-FDA
4.5
1999-USDA
Fresh shell eggs
Control Salmonella species
2000

9. 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

10. Food Irradiation-Safety
Microbiological Safety

11. 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

12. 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

13. Consumer Issues

14. 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

15. The Future ?