By Cat Holmes
University of Georgia
The U.S. Department of Agriculture will make irradiated ground beef available to the nation's school lunch program by January 2004. The recent announcement renewed public debate over the technology of food irradiation, which bombards food with gamma rays, electron beams or x-rays.
At issue, in this case, is children's safety. Is irradiation a technology that might help turn back the rising tide of food-borne illness in U.S. schools? Or are school children going to be used as guinea pigs to research a potentially dangerous food processing technique?
"Study after study has demonstrated that low-level irradiation is safe," said UGA food safety expert Mike Doyle. "The U.S. Centers for Disease Control and Prevention, the American Medical Association, the World Health Organization and the (U.S.) Food and Drug Administration have all blessed irradiation at 10 kilograys or less."
Public knows littleMany people simply don't know much about food irradiation. And the idea scares them, said UGA Extension Service food safety specialist Elizabeth Andress.
"Irradiation is one of the most studied food preparation techniques in history," Andress said. "There is nothing radioactive about the food. And studies haven't been able to detect any changes in food composition other than changes similar to food that has been baked or broiled."
Indeed, irradiation renders food safer, said Doyle, director of the UGA Center for Food Safety and one of the world's leading authorities on E. coli O157:H7.
"It greatly reduces the risk of E. coli and, to a lesser extent, salmonella," Doyle said. "At the low doses used in food irradiation, it won't ensure elimination of harmful microbes in a contaminated product. But it certainly reduces the risk (of food-borne illness)."
Public health problemFood-borne illness is a significant public health problem, and contaminated meat is a major source. The CDC figures food-borne pathogens cause 76 million illnesses, 325,000 hospitalizations and 5,000 deaths each year. In 2002, nearly 50 million pounds of contaminated meat were recalled.
Outbreaks of food-borne illness in U.S. schools have increased by 10 percent in the past decade. Of the 59 largest outbreaks, 40 have been traced to food provided through the federal school meal programs.
While irradiation can greatly reduce the risk of food borne illness, it faces some big hurdles, Doyle said. One is that consumers are suspicious of it. The other is that irradiation can compromise the taste, smell or texture of food.
When meat is irradiated, "free radicals form," Doyle said. "That's what, in large part, kills the bacteria. The fattier the food, the more free radicals form, and they oxidize the fat."
Uh, no thanksThe result, say many who have tried ground beef given pasteurization doses of irradiation, is meat that smells like a wet dog.
Doyle doesn't think this has to be a problem for the federal school lunch program. If the meat is used within a week and processed with a minimum dose of irradiation, he said, the odor doesn't typically occur.
Long-term storage, however, may be a problem. If schools freeze large quantities of meat over the summer, for example, they may have to contend with an odor and taste that will send the kids running.
"Irradiation is a food safety option," Doyle said. "However, it's not the holy grail of food safety."
(Cat Holmes is a science writer with the University of Georgia College of Agricultural and Environmental Sciences.)