Food Irradiation

This article explains the concept and process of food irradiation in plain language, and explores why it is done, how to identify products, and who might benefit from using irradiated food.
Food Irradiation - Articles

Updated: March 1, 2005

Food Irradiation

Food Irradiation

  • is approved by FDA and USDA
  • kills bacteria and insects on food
  • slows spoilage
  • is used to treat meat for the space program
  • offers you a choice in the supermarket

How It's Done

Irradiated food has been exposed to high-energy radiation. Gamma rays, electron beams, or x-ray machines produce this radiation.

Food passes through the beam or rays. Depending on the dose given, insects, larvae, or harmful bacteria are killed.

When your luggage is x-rayed at the airport, it does not become radioactive.

When foods are irradiated, they do not become radioactive.

Why It's Done

Irradiation is used to:

  • kill harmful bacteria (such as Salmonella and E. coli 0157:H7) in meat
  • kill parasites in pork that can cause trichinosis
  • stop potatoes from sprouting
  • kill insects and their larvae in grain, fruits, and vegetables
  • destroy bacteria and insects in spices
  • delay the ripening of fruit

Irradiated food does not decay or spoil as quickly as other foods. So, they have a longer shelf life.

How To Identify It

You have a choice. Irradiated foods can be easily identified. They must carry this symbol:

Manufacturers may also use a statement such as "treated with radiation to control spoilage."

The symbol might be on a sign near a display of fresh produce. It will be on individual food packages if you buy a packaged irradiated raw product.

What It Changes

Cooking produces changes in foods. Irradiation does not cook foods, but it can slightly alter the foods. For instance

  • natural chemicals in the foods may be broken down
  • vitamin content may be slightly reduced
  • off-flavors may develop
  • texture may be somewhat altered

However, most of the changes are similar to those that result from normal cooking, grilling, broiling, canning, or freezing.

Who benefits?

Irradiated foods have much fewer harmful bacteria than other foods. So, irradiated foods are particularly useful for

  • older individuals with increased sensitivity to foodborne illness
  • patients with cancer, HIV, or other illnesses
  • pregnant women
  • young children
  • anyone else unable to fight infections

However, irradiated foods still must be handled carefully to preserve this benefit. Improper food handling can recontaminate irradiated foods in the home.

Prepared by J. Lynne Brown, associate professor food science, and Wei Qin, food science graduate student.


J. Lynne Brown, Ph.D., R.D.