Food%20Irradiation:%20%20Can%20it%20Make%20Food%20Safer?

1
Food Irradiation Can it Make Food Safer?

• History
• What is irradiation?
• Sources and facilities
• Doses used for foods
• Benefits
• Wholesomeness
• Quality
• Cost

2
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 FDC act of 1938 regarding
  food additives

3
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 10kGy 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

4
Who EndorsesFood Irradiation?
5
Who in the World is Irradiating Food?
6
What is Irradiation?
7
Effect of Irradiationon Atoms
Incident photon
The Compton Effect
8
Effect of Irradiationon Molecules
9
Effect of Irradiationon Microorganisms
10
Sources Used for Food Irradiation

• Gamma rays
• produced by Co60 or Cs137
• 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

11
A Word About Radioactivity

• Why FDA permits only Co60 or Cs137
• Co60 has 1.3 MeV of Energy/photon
• Cs137 has 0.67 MeV of Energy/photon
• How much energy needs to be applied to a material
  for it to become radioactive?

12
A Word About Nuclear Waste

• Life cycle of Co60

27Co59 0n1 27Co60
28Ni60
beta
gamma
13
Facilities - Gamma
product already packaged dosimetry recorded
automated processing physical separation
14
Facilities - Linear Accelerator
Electron Gun
15
Irradiation Dose

• Amount of energy absorbed per kg of material
• kGy kilo Gray
• Ranges
• High (sterilization) gt10 kGy
• Medium (pasteurization) 1-10 kGy
• Low (disinfestation) lt1 kGy

16
Applications
Medium dose
High dose
Low dose
17
Current Approvals in U.S.
18
Benefits of Food Irradiation

• Eliminates vegetative cells of
• Escherichia coli O157H7
• Salmonella
• Listeria monocytogenes
• Campylobacter jejuni
• Others

19
Benefits of Food Irradiation

• Shelf-life Extension

20
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

21
Summary ofUS Army/Raltech Study

• Requested by FDA in 1976
• 7 years, 8M cost
• Rats, dogs, mice fed a variety of foods for 4
  generations
• 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 stillbirths

22
Quality of Irradiated Foods
23
Cost of Irradiated Foods
Dose Temperature Thickness
Time Source
Throughput Transport
COST
0.02-0.07/lb ?
24
Future of Food Irradiation?
A Question of Safety and Choice.