1. Food Irradiation Helping Improve Food Safety
The UW Food Irradiation Education Group

2. Why Food Irradiation? Food Safety
In 1999, food-borne disease was responsible for:†
76 million illnesses
325,000 hospitalizations
5000 deaths
$6-30 billion impact
Recent news stories...
† According to US Center for Disease Control

3. Why Food Irradiation? Global Food Supply
Approximately 25% of worldwide food production is lost after harvesting due to insects, bacteria and spoilage†
Economic losses of $5-17 billion annually in the US alone
In the news now….
† According to UN Food and Agriculture Organization

4. What is Food Irradiation?
New commercial technology to eliminate disease-causing germs
Comparable to heat pasteurization
Used for decades in NASA space missions
already used for sterilization of:
medical devices, supplies and implants
wine corks and other food packaging materials
cosmetic ingredients
Single slide introduction to process

5. How Does Food Irradiation Help?
food is exposed to carefully controlled amounts of radiation
radiation damages DNA of microbes and parasites
disease-causing germs are reduced
bacteria which cause spoiling are reduced
sprouting is slowed or stopped

6. What are the Results of Food Irradiation?
When used in conjunction with proper food handling procedures:
food-borne diseases are reduced or eliminated
shelf-life is increased
the nutritional value of the food is preserved
the food does not become radioactive
dangerous substances do not appear in the foods

7. What Foods Can Be Irradiated?
Approval Year
Food
Purpose
1963
Wheat Flour
Control of mold
1964
White Potatoes
Inhibit sprouting
1986
Pork
Kill Trichina parasite
1986
Fruit and Vegetables
Insect Control
Increase Shelf Life
1986
Herbs and Spices
Sterilization
1990(FDA)
1992(USDA)
Poultry
Bacterial
pathogen
reduction
1997(FDA)
1999(USDA)
Meat

8. Puchasing Irradiated Food?
All irradiated products must be marked with the “Radura”
Irradiated meats expected to be more widely available this summer
If interested, ask your local grocery retailer

9. Benefits of Food Irradiation
decreased incidence of food-borne illness
reduced spoilage in global food supply
increased level of quality assurance in international trade of food products
Single slide summary of social benefits - related to previous slide on motivation.

10. Food Irradiation Facilities
SOURCE HOISTS
SOURCE PASS CONVEYOR
UNLOADING ELEVATOR
IRRADIATION ROOM
CONTROL CONSOLE
LOADING ELEVATOR
JS8900 UNIT CARRIER IRRADIATOR

11. Three different energy sources electron beams
a beam of electrons is accelerated by an electron gun
similar to a TV tube, accelerating electrons towards the screen
it can be turned on or off since it uses no radioactive material, but…
electron beams can only penetrate about 1” into material

12. Three different energy sources x-rays
generated by directing an electron beam at a thin metal plate
similar to medical x-ray sources

13. Three different energy sources gamma rays
emitted from spontaneous radioactive decay
“pencils” of naturally occurring non-radioactive cobalt metal (59Co)
neutron bombardment in reactor to produce radioactive cobalt (60Co)
“turned-off” by lowering Co source into storage pool

14. Effects of radiation How it kills bacteria
radiation damages DNA of organisms
if the damage is not automatically repaired the organism will be unable to replicate itself
chance of DNA damage related to size of DNA
irradiation more effective on bacteria than viruses
This information could easily, if tangentially/inappropriately, raise issues of low-level radiation effects on living organisms. Differences:
large organisms can afford to have some individual cells die without harmful effects - it is, in fact, part of the process of life
this is the reason that radiation is damaging at high doses - it kills more cells than the organism can handle
(a related curiosity: Is the single-celled equivalent of cancer basically the creation of a new species? Is this an interesting or relevant issue?)

15. Effects of radiation Effect on Food
most food is made up of dead cells
DNA damage is irrelevant
living cells cause sprouting and spoilage
DNA damage delays spoiling and prevents sprouting
longer shelf-life

16. Effects of radiation Side-effects
Nutritional effects
macronutrients - proteins, carbohydrates, fats - unaffected
micronutrients - vitamins - some reduction
comparable to other processing or storage techniques including pasteurization, canning, or even cold storage
No change in taste

17. Costs of Food Irradiation
Like any food process, irradiation will add to the cost of the food
initially 2-3¢/lb for produce, 3-5¢/lb for beef
expected to decrease as it becomes more common
Typical food irradiation plant: $3-5 million
compare to
moderately sized pasteurization plant: $2 million
small vapor-heat treatment for fruits: $1 million

18. Safety of Irradiation Facilities
Over 30 yrs of experience
100+ medical sterilization plants
medical radiation treatment centers
bone marrow transplant centers
No public exposure to radiation
Independent regulators:
gamma rays: NRC
X-rays & e-beams: FDA

19. Facility Accidents and Waste
Severe accidents are not possible
electron beam and x-ray sources can be easily turned off
gamma ray sources cannot blow up
The facility itself cannot become radioactive
no radioactive waste
used Co-60 gamma sources can be recycled/regenerated

20. Food Irradiation as Part of Comprehensive Food Safety
food irradiation is not a replacement for comprehensive food safety
in particular, food irradiation cannot reverse the spoilage process
irradiated foods need to be stored, handled and cooked in the same way as unirradiated food

21. Benefits of Food Irradiation
disease-causing germs are reduced or eliminated
the nutritional value of the food is preserved
decreased incidence of food-borne illness
reduced spoilage in global food supply
increased level of quality assurance in international trade of food products

22. Food Irradiation Means Safer Food
The UW Food Irradiation Education Group

23. Radiation dose the quantity of radiation absorbed by the food
measured in Grays (Gy)
1 Gy = 1 Joule absorbed per kilogram of food
international health and safety authorities have endorsed radiation levels for food up to 10,000 Gy (10 kGy)

24. What Foods Can Be Irradiated?
Approval Year
Food
Dose (kGy)
Purpose
1963
Wheat Flour
Control of mold
1964
White Potatoes
Inhibit sprouting
1986
Pork
Kill Trichina parasite
1986
Fruit and Vegetables
1.0
Insect Control
Increase Shelf Life
1986
Herbs and Spices 30
Sterilization
1990(FDA)
1992(USDA)
Poultry
3(FDA)
1.5-3(USDA)
Bacterial
pathogen
reduction
1997(FDA)
1999(USDA)
Meat
4.5