Transcript The Facts on Food Irradiation

Food Irradiation
Helping Improve Food Safety
The UW Food Irradiation
Education Group
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
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
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
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
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
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
1997(FDA)
1999(USDA)
Meat
Bacterial
pathogen
reduction
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
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
Food Irradiation Facilities
SOURCE HOISTS
SOURCE PASS CONVEYOR
UNLOADING ELEVATOR
IRRADIATION
ROOM
CONTROL CONSOLE
JS8900 UNIT CARRIER IRRADIATOR
LOADING ELEVATOR
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
Three different energy sources
x-rays
• generated by directing an electron beam
at a thin metal plate
• similar to medical x-ray sources
Cosmic
Rays
Gamma
Rays
X-Rays
Ultraviolet
(Sun Rays)
Visible
Light
Infrared
(Heat Waves) Microwaves Radio Waves
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
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
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
å longer shelf-life
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
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
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
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
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
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
Food Irradiation
Means Safer Food
The UW Food Irradiation Education Group
http://uw-food-irradiation.engr.wisc.edu
[email protected]
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)
What Foods Can Be Irradiated?
Approval
Year
Food
Dose
(kGy)
Purpose
1963
Wheat Flour
0.2-0.5
Control of mold
1964
White Potatoes
0.05-0.15
Inhibit sprouting
1986
Pork
0.3-1.0
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)
1997(FDA)
1999(USDA)
Meat
4.5
Bacterial
pathogen
reduction