Iowa State University

Inside Iowa State
Mar. 06, 1998

Is irradiated meat ready for prime time?

by Brian Meyer, Ag Information Service

Ground beef took a beating in 1997. A contamination scare prompted the nation's biggest food recall -- more than 25 million pounds of ground beef. South Korea detected E. coli in U.S. beef exports. E. coli also was found in beef imported from Canada. And still fresh in many consumers' minds were the tainted fast-food burgers that killed three and sickened hundreds a few years ago.

Can anything repair the damage to ground beef's reputation?

Dennis Olson believes irradiation can.

"Irradiation could have prevented all those problems," said the professor of animal science and food science and human nutrition. Olson directs Iowa State's Linear Accelerator Facility, the nation's only commercial-sized irradiation facility for food research and demonstration.

Many who favor irradiation have been reluctant to say the technology is a silver bullet. "But it's as close as we're likely to get," Olson said. "It's an extremely powerful tool for improving food safety for red meat."

The Food and Drug Administration recently approved irradiation for red meat after studying the issue for three years. After the ground beef crises last year, pressure had mounted to speed up the approval process. Olson testified in Congress and was quoted widely on irradiation's potential.

"The beauty of irradiation is that it can be used on packaged meat, so it's the last step before distribution," he said. "When consumers and restaurants open that package, they can be assured it's free of disease-causing bacteria."

Some worry adoption of irradiation will mean less vigilance in other links along the meat chain. Olson disagrees.

"When pasteurization of milk was adopted, some expected dairies to become dirtier. Just the opposite happened," Olson said. "Any producer or company that wants to stay in business will need to deliver a uniform, high-quality product. If you're sloppy, you won't stay in business. And irradiation can only kill bacteria; it can't clean up physical contaminants."

Livestock industry officials agree irradiation is needed.

"Its time has come," said Mark Williams, assistant vice president of the Iowa Cattlemen's Assn., which has supported ISU irradiation research. "We need to assure our customers that we are using processes that ensure the safest and most responsibly produced beef products possible."

Rich Degner, associate director of the Iowa Pork Producers Assn., said, "We're excited about the technology and very supportive of ISU's work. We believe irradiation is another technological advance, like refrigeration, that will extend the shelf life of meat."

This technological advance doubles meat's shelf life, Olson said. "Ground beef's shelf life is about 12 days. Irradiation extends that to 24 days. A vacuum-packaged pork loin's shelf life would increase from 40 days to 80 days."

Soon after Iowa State's linear accelerator began operating in 1993, Olson and other researchers confirmed what already was indicated from earlier irradiation studies -- bacteria on meat and other foods don't stand a chance.

The linear accelerator uses electricity to generate and aim a beam of electrons. It's similar to the system that brings an image to a television screen, although many times more powerful. The electron beam scans food products, wiping out salmonella, E. coli and other disease-causing organisms.

ISU research has focused on answering questions of importance to the meat industry, which will be looking at implementing the technology. Olson said the biggest hurdle isn't consumer acceptance of irradiated meat -- studies at ISU and elsewhere have shown they are willing to pay for safer foods. It's packaging.

"The FDA has approved just one family of resins for use in packaging irradiated products," Olson said. "But many new kinds of packaging contain several combinations or layers of materials. Instead of seeking approval for each kind of packaging, it makes sense to try to get the raw materials approved. We're now testing many individual components used in plastics and adhesives to see which ones are the most suitable for irradiation."

Besides research, teaching and outreach also are important, said Jim Dickson, a microbiologist and irradiation specialist working with Olson.

"For two years, we've been teaching food scientists from other countries about irradiation," Dickson said. "We offer our services to companies that want to test products in our facility. And we continue to educate people about irradiated foods."

Dickson and Olson are members of the Food Safety Consortium, a three-university meat safety research program. Irradiation is only one of several approaches ISU scientists in the consortium are studying to improve meat safety along the food chain -- from farms to processing plants, supermarkets to dinner tables.

Dickson believes the first to use meat irradiation will be companies that supply food to nursing homes and hospitals, where limiting exposure to disease is especially critical.

Although the adoption process may be slow because of a lack of irradiation facilities, Olson said the meat industry will be thinking seriously about it.

"Everybody working with ground beef knows the problems that occurred in 1997 could have happened to them," he said. "It's as good an argument as any for irradiation."

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