Food Irradiation: Can it Make Food Safer? HistoryHistory What is irradiation?What is irradiation? Sources and facilitiesSources and facilities Doses used for foodsDoses used for foods BenefitsBenefits WholesomenessWholesomeness QualityQuality CostCost

History of Food Irradiation 1921Schwartz publishes studies on lethal effect of irradiation on Trichinella in pork1921Schwartz publishes studies on lethal effect of irradiation on Trichinella in pork 1953“Atoms for Peace” program launches food irradiation research in U.S.1953“Atoms for Peace” program launches food irradiation research in U.S. 1955Research in Europe begins1955Research in Europe begins 1958Amendment to FD&C act of 1938 regarding food additives1958Amendment to FD&C act of 1938 regarding food additives

History of Food Irradiation 1976Joint expert committee (IAEA, WHO, and FAO) declares food irradiation a process1976Joint expert committee (IAEA, WHO, and FAO) declares food irradiation a process 1980Same expert committee declares foods irradiated at up to 10kGy to be wholesome1980Same expert committee declares foods irradiated at up to 10kGy to be wholesome 1997Same expert committee declares foods irradiated at ANY DOSE to be as wholesome and safe as foods treated by any conventional processing treatment1997Same expert committee declares foods irradiated at ANY DOSE to be as wholesome and safe as foods treated by any conventional processing treatment

Who Endorses Food Irradiation?

Who in the World is Irradiating Food?

What is Irradiation?

Effect of Irradiation on Atoms Incident photon The “Compton Effect”

Effect of Irradiation on Molecules

Effect of Irradiation on Microorganisms

Sources Used for Food Irradiation Gamma raysGamma rays –produced by Co 60 or Cs 137 –penetrate ~3 ft. material Accelerated electronsAccelerated electrons –produced by linear accelerator –penetrate ~3/4 in. (1.5 in. double-sided) X-raysX-rays –produced by linear accelerator –penetrate ~3 ft. material

A Word About Radioactivity Why FDA permits only Co 60 or Cs 137Why FDA permits only Co 60 or Cs 137 –Co 60 has 1.3 MeV of Energy/photon –Cs 137 has 0.67 MeV of Energy/photon –How much energy needs to be applied to a material for it to become radioactive?

A Word About Nuclear Waste Life cycle of Co 60Life cycle of Co Co n 1 27 Co Ni 60 beta gamma

Facilities - Gamma * product already packaged * dosimetry recorded * automated processing * physical separation

Facilities - Linear Accelerator Electron Gun

Irradiation Dose Amount of energy absorbed per kg of materialAmount of energy absorbed per kg of material kGy = kilo GraykGy = kilo Gray Ranges:Ranges: –High (sterilization): >10 kGy –Medium (pasteurization): 1-10 kGy –Low (disinfestation): <1 kGy

Applications High dose Medium dose Low dose

Current Approvals in U.S.

Benefits of Food Irradiation Eliminates vegetative cells of:Eliminates vegetative cells of: –Escherichia coli O157:H7 –Salmonella –Listeria monocytogenes –Campylobacter jejuni –Others

Benefits of Food Irradiation Shelf-life ExtensionShelf-life Extension

The Question of Wholesomeness Total of 1221 studies conducted up to 1979 on wholesomeness of 278 different foods fed to a variety of animals resulted in no significant difference between irradiated and nonirradiated foods in terms of: toxigenicity, pathogenicity, or mutagenicity

Summary of US Army/Raltech Study Requested by FDA in 1976Requested by FDA in years, $8M cost7 years, $8M cost Rats, dogs, mice fed a variety of foods for 4 generationsRats, dogs, mice fed a variety of foods for 4 generations Frozen vs. Canned vs. Irradiated (56kGy)Frozen vs. Canned vs. Irradiated (56kGy) –Highest incidence of neoplasms (frozen food!) –Lowest fertility after 3 generations (canned food!) –Irradiated food caused NO reduction in offspring, increase in stillbirthsreduction in offspring, increase in stillbirths

Quality of Irradiated Foods

Cost of Irradiated Foods DoseTemperatureThickness TimeSource ThroughputTransport COST $0.02-$0.07/lb ?

Future of Food Irradiation? AQuestion of Safety andChoice.