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SAFEFOOD NEWS - Fall 1997 - Vol 2 no 1

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At the Processing Plant: Pasteurization Process May Reduce E. Coli Contamination

A meat decontamination process developed by Kansas State University food microbiology researchers for two of the world's largest meat processing companies is showing great promise as an effective weapon for killing E. coli and salmonella bacteria at the processing level.

The Steam Pasteurization System 400 is a new technological concept in meat safety, according to Randy Phebus, a K-State assistant professor in the Department of Animal Sciences and Industry. The anti-microbial treatment, developed for Frigoscandia of Seattle, Washington, and Cargill of Minneapolis, Minnesota, 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, can be 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. This raises the surface temperature to 185 F. 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§F 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 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.

Since receiving USDA approval for the design in December 1995, six SPS 400 units have been installed in North America. Fifty 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.

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.

Source: Kansas State University News Services, Manhattan, KS, August 27, 1997.

Updated Monday, August 29, 2011