Irradiated Food: An Overview
Irradiation is the use of radiation from x-rays or radioactive materials on food. The process sterilizes food. The benefits of irradiating food include the ability to control insects and bacteria. The process can give foods, especially fruits and vegetables, a longer shelf life and cause less
However, the topic of irradiation seems to be one surrounded by as much myth as fact. For example, food irradiation does not make the food radioactive.
What Is Food Irradiation?
Food irradiation, like pasteurization or canning, is a food safety technology designed to eliminate the germs, bacteria, and parasites that would otherwise cause foodborne diseases from the foods we eat. It has been approved for use in the US since 1963. It is also used in many other countries, including, China, Russia, and Portugal. The World Health Organization (WHO) and government agencies support the use of irradiation.
What Is it Used for?
There are four main purposes of food irradiation:
- Preservation—Irradiation extends the shelf life of a food by destroying or inactivating organisms in the food that may cause spoilage and decomposition.
Sterilization—Because of the sterilization process, these foods can be given to people with severely-impaired immune systems. In addition, both NASA and the military use irradiated food as a means of preventing foodborne illness.
- Reduce sprouting, ripening, and damage from bugs—Irradiation is sometimes used in place of chemicals to prevent damage to food. This process is particularly useful for products like potatoes, tropical and citrus fruits, grains, spices, and seasonings.
- Reduce foodborne illness—Irradiation destroys organisms that may cause illness.
What Does the Process Involve?
The process can involve these technologies:
- Gamma rays—a radioactive element is used to irradiate the food; it can be used with thick foods
- Electron beams—a stream of high-energy electrons are shot through an electron gun (it is used to treat foods that are not thick)
- X-ray irradiation—electrons are sent through a metal plate to create a x-ray on the other side of the plate (it can be used with thick foods)
Does the Process Change Food?
Despite some of the myths you may have heard, food irradiation does not change the nutritional value of the food or make it dangerous to consume. Some foods may be slightly warmed by the process, and others may taste somewhat different. Afterwards, food that has been irradiated can be handled in the same way that you would any other food.
How Can You Tell?
In general, the changes to food caused by the irradiation process are so minimal that distinguishing an irradiated food from a nonirradiated food can be difficult. In the US, all manufacturers of irradiated foods are required to put an international symbol, called the
on their products and to include a description of the process on their product labels.
A Final Word
It is important to remember that purchasing irradiated food is no guarantee of its safety. Food irradiation does not replace proper food production, processing, handling, storage, or preparation, nor can it enhance the quality of or prevent contact with foodborne bacteria after irradiation. Therefore, the rules of basic food safety must still be followed:
- Raw meat, fish, poultry, and dairy products should be as fresh as possible at the time of purchase. Buy products with the longest shelf life.
- Place raw meat, poultry, and fish away from any cooked foods or fresh produce in the grocery cart.
- Store refrigerated foods below 40°F.
- Wash hands before, during, and after food preparation.
- Store all leftovers within 2 hours by placing them in tightly sealed, shallow containers.
- Eat leftovers within 3-4 days for safety.
American Academy of Nutrition and Dietetics
US Food and Drug Administration
Dietitians of Canada
Food irradiation: What you need to know. US Food and Drug Administration website. Available at: http://www.fda.gov/Food/IngredientsPackagingLabeling/IrradiatedFoodPackaging/ucm261680.htm. Updated November 7, 2014. Accessed April 29, 2015.
Irradiated foods. American Council on Science and Health website. Available at: http://acsh.org/2003/05/irradiated-foods-2. Accessed April 29, 2015.
Irradiation of food. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/nczved/divisions/dfbmd/diseases/irradiation%5Ffood. Updated November 19, 2009. Accessed April 29, 2015.
Refrigerator thermometers: Cold facts about food safety. US Food and Drug Administration website. Available at: http://www.fda.gov/Food/ResourcesForYou/Consumers/ucm253954.htm. Updated March 10, 2015. Accessed April 29, 2015.
The facts. University of Wisconsin Food Irradiation Education Group website. Available at: http://uw-food-irradiation.engr.wisc.edu/Facts.html. Accessed April 29, 2015.
The good, the bad, the reheated: Cooking and handling leftovers. US Department of Health and Human Services Food Safety website. Available at: http://www.foodsafety.gov/blog/holiday%5Fleftovers.html. Accessed April 29, 2015.