Irradiation
Food irradiation has been described as a safe technology used to reduce the risk of food borne illnesses. The goal of irradiation is to inactivate undesirable microorganisms and pests in food, while maintaining quality products. In addition to this goal irradiation improves the shelf life and the safety of food products. A common phrase given to this process is "cold pasteurization".
Contrary to many beliefs, food that is irradiated never comes in contact with the radioactive material. The process has very little effect on the food because the food cells are not multiplying. The cells that are actively multiplying such as insects, fungi, and bacteria are the cells that are affected.
The irradiation process does not leave a residual as seen in the use of pesticides. This makes these methods desirable to the public. In addition to the insect problem, fruits that were not allowed on the mainland from Hawaii are now allowed if they have been irradiated.
Is Irradiation a new concept?
Irradiation began as a result of "Atoms for Peace" in the early 1950's by President Eisenhower. Many studies have been tested for years to determine its effectiveness and safety.
Is the United States the only place where irradiation is done?
No. Over 30 countries have approved the use of irradiation, and 20 countries currently are using irradiation for food preservation.
Does irradiation affect the nutritional value of the food?
Not really. The affect that it does have is so small that it does not change the protein and other nutritional values. There is some concern as to how it affects the light and heat sensitive nutrients such as vitamin B and ascorbic acid (vitamin C). To avoid vitamin losses it is recommended that the foods be irradiated under refrigerated temperatures with light and oxygen excluded.
Does the food taste different than non-irradiated foods?
Many taste tests have been conducted. The results are amazing. A taste test with hamburgers indicated that consumers preferred the irradiated burgers. The only difference between the irradiated and non-irradiated was that the irradiated samples were perceived to be more tender and juicier.
Do you know when you are buying irradiated food?
Yes. All irradiated retail food must have the international symbol on the label. This symbol is called the Radura symbol.
Will irradiated foods cost more?
Very little. It is estimated that the cost increase will be 2-3 cents per pound of fruit and 3-8 cents per pound of meat.
Is irradiation used on anything else?
Yes. In fact, the first commercial irradiation of medical devices took place in 1955 in Scotland by a division of Johnson & Johnson. The first thing to be sterilized was a catgut suture. Irradiation was used instead of steam or heat, because both methods caused the cat, gut sutures to become brittle.
Today it is estimated that 80-90% of all disposable medical plastics produced are sterilized by irradiation.
What do they use to irradiate?
Cobalt-60, Cesium-137, electron beam, and X-rays are the most common ways to irradiate. Both Co-60 and Ce-137 give off gamma rays, which is the most intense process. Electron beam has a very low penetrating ablity and cannot be used for irradiation of thick materials (more than 3 inches thick).
Electron beam processing utilizes high-energy electrons. This is a safer way to irradiate; in that when the switch is turned off there is no concern for safety as with a gamma source. Additionally there is no radioactive waste of hazardous transportation associated with electron beam processing.
References:
http://www.idexx.com/fed/fsn/442120198.asp
http://scan.titan.com/services/ebeam_tech.html
"Position of The American Dietetic Association: Food Irradiation." ADA Reports. Vol 100 Number 2. Feb. 2000.
Thayer, Donald W. "Radiation Pasteurization of Food." Council for Agricultural Science and Technology. Issue Paper Number 7. April 1996.