PASTEURIZATION PROCESS MAY EASE CONSUMER E. COLI CONCERNS

MANHATTAN -- A meat decontamination process developed by Kansas State University food microbiology researchers for two of the world's largest meat processing companies is being billed as the most effective weapon in killing the dangerous E. coli and salmonella bacteria.

The Steam Pasteurization System 400 is a new technological concept in meat safety, according to Randy Phebus, a K-State assistant professor of food sciences in the department of animal sciences and industry. The antimicrobial treatment, developed for Frigoscandia of Seattle, Wash., and Cargill, of Minneapolis, Minn., uses pressurized steam rather than chemicals to kill these pathogens on slaughtered animals. It was awarded an international innovation award in France last October.

"For the first time we have a very reliable, very effective treatment where raw animal carcasses pass through a 37-foot-long tunnel that applies large quantities of steam to the carcass surface," Phebus said. "This kills a large percentage of bacteria on carcass surfaces and greatly reduces the risk of enteric pathogens such as E. coli and salmonella in the meat supply."

According to Phebus, the pathogens, found in the intestinal tracts of cattle, are passed on to the meat's surface during the slaughtering process either through skinning the animal, removing the intestinal tract, handling the carcass or through other means.

Following standard wash and dry procedures the carcass is immersed in pressurized steam to envelope every square inch for six to eight seconds in the SPS 400. This raises the surface temperature to 185 degrees. Phebus said the brief amount of time the carcass is exposed to those temperatures is more than adequate to kill bacteria.

The carcass is then immediately sprayed with chilled water, bringing the surface temperature down to 65 degrees Fahrenheit before it is stored in a holding cooler. Phebus said this rapid procedure prevents discoloration and a "cooked look" of the carcass, which is unacceptable for consumers desiring a fresh-looking product.

Phebus said the steam pasteurization process is superior to other decontamination technologies because it does not involve environmental issues, is economical and energy efficient. Other processes have been previously tried but were unable to consistently provide the amount of microbial kills desired.

"For 30 years people have tried to use steam for different applications but they met with a lot of obstacles that they could never master from an engineering standpoint," Phebus explained.

Phebus cautions the new technology only reduces the risk of bacteria. Ultimately the most important role in food safety, which includes proper handling and preparation of meat, belongs to the consumer.

"We don't claim to sterilize the meat," Phebus said. "Even if we did, as the meat carcass goes on down the line it's handled, it's cut; there are opportunities to reintroduce bacterial contamination."

Since receiving USDA approval for the design in December 1995, six SPS 400 units have been installed in North America. An SPS 400 was recently installed at a facility in Dodge City. Another 50 facilities are scheduled to receive systems in the next year and a half. Phebus said a large percentage of meat slaughtered in this country will soon be decontaminated using this process.

Phebus is working on a smaller version of the SPS 400 that will allow more "batch-type" decontamination of 60 carcasses per hour and possibly pasteurization for poultry and pork. A system that will decontaminate beef trimmings used to produce ground beef is currently being developed with Frigoscandia, Cargill and McDonald's.

"Our major problem with E. coli has been with ground beef products," Phebus said. "After you grind it up it's very difficult to get rid of the bacteria other than through cooking it. If you can decontaminate the surfaces of the trim before you grind it, then you've made a major step forward in food safety."

Phebus said the potential for this technology is unlimited. Decontamination of raw fruits, vegetables and the surface of eggs are other possible uses for the technology.

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For more information contact Randall Phebus at 785-532-1215

Prepared by Keener A. Tippin II

February 1997