"Irradiation exposes food to very short light waves with very high energy," said Elizabeth Andress, a food safety specialist with the UGA Extension Service.
"The process can kill microorganisms that can cause disease or can cause the food to spoil," she said. "It can also kill insects in grains and spices."
The process, approved for use on fresh chilled or frozen meats only since last December, is fairly simple. Conveyors carry large cases of food on pallets past an irradiation source in an enclosed chamber.
It sounds like new-age technology. But it's been around since the turn of the century.
"The first patent application for food preservation by irradiation was filed in 1905," Andress said. "But it has really only been used in the past 40 years."
Food irradiation offers many benefits. It extends the shelf life of food by preventing sprouting, deactivating mold and killing spoilage bacteria. The United Nations figures more than 25 percent of the world's harvest is lost to spoilage and waste.
"Irradiation also cuts down the number of chemicals in food," Andress said, "by replacing fumigants and other pesticides used to preserve food supplies."
Irradiation kills microorganisms that cause food-borne illness and parasites that cause disease. But like canning and freezing, it may not destroy preformed toxins and viruses.
And when gamma rays are aimed at food, questions of safety are bound to arise.
Andress said some groups that once opposed the process have become supporters. But others still oppose it.
"The typical issues raised by those opposed to the process are the safety of radioactive materials in food processing facilities, the reduction in nutritive content and the possible cancer-causing products formed in the foods during the irradiation process," she said.
"Extensive research shows that the chemical compounds found in irradiated foods are identical to those found in baked or broiled food," she said. "The nutritional quality of irradiated food is essentially the same as that of fresh food."
The value of the food is affected more by how the food is stored.
"Irradiation of meat could prove to be another important tool to protect consumers from food-borne disease," said Michael Friedman, deputy commissioner of the U.S. Food and Drug Administration. "The process has been shown to be safe and to significantly reduce bacterial contamination."
But will shoppers accept it?
One survey shows that to get safer food, shoppers are willing to pay more than it costs to irradiate it.
In recent surveys, 72 percent of consumers were aware of the process, but 88 percent of those knew little about it. However, they were less concerned about irradiation than food additives, pesticide residues, animal drug residues, growth hormones and bacteria.
Risks to workers and the environment were the chief concerns among these shoppers.
Shoppers can tell if food has been irradiated by the label.
"There may be some changes in the labeling requirements for irradiated foods," Andress said. "The FDA has been directed to revise the disclosure statement. The green symbol can continue to be used. And labeling will continue to be required."
Irradiated food is making its way to the marketplace, but only in small amounts. Nation's Pride is the first retail brand handling only irradiated products, primarily produce.
Graphic by Cindy M. Esco, UGA CAES
Download the .JPG here
Web sites to see for information on food irradiation include: FDA: <http://www.cfsan.fda.gov/~lrd/fr97123a.html> or <http://www.fda.gov/bbs/topics/NEWS/NEW00603.html>; Council for Agricultural Science and Technology, <http://www.netins.net/showcase/cast/past_ip.htm>; or USDA, <http://www.usda.gov/agency/fsis/irrad_cw.htm>.
(Faith Peppers is the director of public affairs with the University of Georgia College of Agricultural and Environmental Sciences.)