Irradiation Reduces Bacteria in Food

Irradiation Reduces Bacteria in Food
Irradiation Reduces Bacteria in Food

June 25, 2003

URBANA - Incidents of deadly bacteria found in meat and poultry have raised public health concerns. And although irradiating the meat would greatly reduce outbreaks of E.coli and Salmonella, fear of the food becoming radioactive has prevented the process from becoming widely accepted in the United States.

Irradiation was approved for use on certain foods by the U.S. Food and Drug Administration in the early 1960s. Not only does it decrease bacteria in foods, it also reduces spoilage and delays ripening so produce can stay fresh longer.

"The process of irradiation kills only living things," said Stoyan Toshkov, a research specialist in food irradiation at the University of Illinois. "So, for example, it eliminates bacteria like E. coli."

When food is irradiated, it is passed through a radiation field using gamma rays produced from radioactive cobalt-60 or electrons from an accelerator. Neither technique makes the food radioactive, nor does it change the nutritional content of the food more than any other common cooking process such as boiling, baking or microwaving. It is similar to luggage being sent through an airport scanner.

"Some years ago a shipment of chicken was sent to Russia from the U.S.," said Toshkov. "It was rejected due to unacceptable levels of Salmonella, but it would have been free of Salmonella if the poultry had been irradiated prior to being shipped."

Faye Dong, head of the Department of Food Science and Human Nutrition at the University of Illinois recalled an incident involving a fast food chain in Seattle in which several children died or were permanently disabled due to eating E. coli 0157:H7 contaminated hamburger or having contact with infected children.

When she was working at the University of Washington, one of her research projects was to study the effects of irradiation of dairy products for cancer patients who had undergone bone marrow transplants and were on low microbial or sterile diets. "I kept thinking that if the hamburger meat served by that restaurant had been irradiated to kill bacteria, those victims might still be alive and well today," she said.

Toshkov stressed that routinely irradiating meat could protect the more vulnerable members in our population from foodborne bacteria like E.coli. "Approximately 70 percent of the ground beef produced in the U.S. supplies fast food restaurants, schools and prisons," he said. "In a cut of meat, the bacteria may only be present on the surface, but in the grinding process it is spread throughout the entire batch."

The meat industry in the U.S. is not resisting irradiation, but the process is not required. "I would like to see grocery stores in the U.S. at least offer customers the choice of buying irradiated meat," he said.

Toshkov works with U of I graduate students on food irradiation research. "When something is unfamiliar, it can seem dangerous," he said. "But when students become familiar with irradiation and understand that it is not dangerous when used properly, they can see the benefits."

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