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 ?