MANHATTAN, Kan. – Kansas State University researchers are testing a new, steam-based pasteurization system that moves food safety another step closer to the American consumer.

They’re pasteurizing the surface of hot dogs, ham, pepperoni and other ready-to-eat (RTE) meats after final packaging. So far, the scientists are finding that pasteurization kills any disease-causing bacteria present on the wrapped foods’ surface.

The product is not handled again by human hands – the most common source of contamination on the exterior surface of foods – until it reaches the consumer’s kitchen or a retail deli.

"In a lot of fully-cooked RTE meat products, you have to take some cooking casings or packaging material off, so it has to be re-handled in the plant prior to final packaging," said Ed Ater, a spokesperson for Stork RMS-Protecon Inc. of Gainesville, Ga., the company that built the post-processing pasteurization unit.

"During this re-handling is when you increase the potential for environmental contamination of the product’s surface."

Food scientists are interested in finding a system to decontaminate ready-to-eat meats because some emerging technologies – such as irradiation – are not USDA- or FDA-approved for these products. Some ready-to-eat meats have been contaminated during post-cooking processes with listeria monocytogenes, which one K-State researcher says is "an equal threat" to consumers as the more publicized E. coli 0157:H7.

"When I see news reports of a child’s dying from a contaminated hot dog, it breaks my heart, because it shouldn’t be happening," said Randy Phebus, K-State Research and Extension meat microbiologist. "We have the technology to prevent that or at least make it unlikely that something like that will happen in the future."

In post-process pasteurization, packaged meats are exposed to condensing steam (approximately 195 degrees F) for two to four minutes. Then, the product moves into an ice bath or other chilling unit.

Phebus said that because post-process pasteurization also kills spoilage bacteria, it can extend meat’s shelf life. But the K-State researchers’ main goal is to eliminate foodborne pathogens.

"This system will be a final point – before it goes to the consumer – of taking care of any external contamination on ready-to-eat meats," Phebus said.

In January, Stork RMS-Protecon built a post-process pasteurization test model at Kansas State University so that food scientists could test time and temperature combinations for decontaminating RTE meats. In Europe, a similar Stork-built unit is being used to cook ready-to-eat meats. At K-State, however, the scientists are only concerned with pasteurizing the surfaces of these products.

"In a matter of two to three weeks, we could be ready to have this out to the general market," Ater said. "Honestly, it should have been in the United States two or three years ago.

"We’ve had the system [in Europe] for many years. But there was very little interest in pursuing it [in the United States] because the public did not perceive any problems [with ready-to-eat meats]."

Phebus likened the pasteurization of meats to the pasteurization of milk.

"We have grown to accept milk in the marketplace as one of our safest foods," he said. "I think the same is going to happen in RTE meat and poultry products fairly soon."

Work in Kansas also is increasing the safety of sliced meats, such as bologna and ham. An Ohio company, STERIS Corporation, has constructed a K-State "clean room," where slicing and packaging is done under highly-controlled, aseptic conditions similar to surgical rooms’.

"Clean rooms are being built at meat processing facilities to ensure that sliced products do not become contaminated with listeria," said STERIS spokesman Bill Biebesheimer.

U.S. scientists also are testing other pasteurization systems, such as hot water baths, Phebus said.

"[Kansas State] is by no means endorsing one technology, but we have shown that steam is very effective in decontaminating meats," he said. "We have lots of experience in using steam at Kansas State University and we feel confident that we can take this technology further to provide a reasonable process for the industry."

Phebus said the impact of using post-process pasteurization could be large: "Millions of pounds of ready-to-eat meats" are processed every year.