Food Irradiation Can it Make Food Safer History

Food Irradiation: Can it Make Food Safer? • • History What is irradiation? Sources and facilities Doses used for foods Benefits Wholesomeness Quality Cost

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

History of Food Irradiation • 1976 Joint expert committee (IAEA, WHO, and FAO) declares food irradiation a process • 1980 Same expert committee declares foods irradiated at up to 10 k. Gy to be wholesome • 1997 Same 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 rays – produced by Co 60 or Cs 137 – penetrate ~3 ft. material • Accelerated electrons – produced by linear accelerator – penetrate ~3/4 in. (1. 5 in. double-sided) • X-rays – produced by linear accelerator – penetrate ~3 ft. material

A Word About Radioactivity • Why FDA permits only Co 60 or Cs 137 – Co 60 has 1. 3 Me. V of Energy/photon – Cs 137 has 0. 67 Me. V 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 60 59 + Co 27 1 n 0 60 Co 27 60 Ni 28 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 material • k. Gy = kilo Gray • Ranges: – High (sterilization): >10 k. Gy – Medium (pasteurization): 1 -10 k. Gy – Low (disinfestation): <1 k. Gy

Applications Medium dose High dose Low dose

Current Approvals in U. S.

Benefits of Food Irradiation • Eliminates vegetative cells of: – Escherichia coli O 157: H 7 – Salmonella – Listeria monocytogenes – Campylobacter jejuni – Others

Benefits of Food Irradiation • Shelf-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 1976 7 years, $8 M cost Rats, dogs, mice fed a variety of foods for 4 generations • Frozen vs. Canned vs. Irradiated (56 k. Gy) – – – Highest incidence of neoplasms (frozen food!) Lowest fertility after 3 generations (canned food!) Irradiated food caused NO • reduction in offspring, increase in stillbirths

Quality of Irradiated Foods

Cost of Irradiated Foods Dose Temperature Time Thickness Source Throughput Transport COST $0. 02 -$0. 07/lb ?

Future of Food Irradiation? A Question of Safety and Choice.