February 27, 2001 - LIVE From the OSU Thermal Processing Course: Is Listeria On The Wane?

COLUMBUS, Ohio -- A group of 45 industry leaders and meat processors gathered yesterday morning in the Agricultural Administration building on the campus of The Ohio State University for a short course in Thermal Processing of Ready-to-Eat Foods. Randy Huffman, vice president of scientific affairs for the American Meat Institute Foundation, kicked off the course with advice for the industry.

"There are three over-arching goals," he said. "To protect public health, to protect corporate health, and to comply with regulations. The most important reason we're here is to learn about and protect public health.

"Listeria and salmonella are two key food-borne pathogens about which all processors must be concerned, Huffman said. According to the Centers for Disease Control and Prevention, salmonella and listeria account for almost 60 percent of all deaths from food-borne pathogens.

"As chief microbiologist, President Clinton said last year we would reduce listeria incidents by 50 percent by 2005," Huffman joked.

But the industry is working toward that goal, Huffman pointed out. The Food Safety and Inspection Service data show that positive results for listeria in lunchmeats and hot dogs have decreased to 6 percent in 1999 from 11 percent in 1989.

"We are improving," Huffman stressed. "We're not down to zero, but we're making progress.

"Meat processors must understand and comply with the Federal Meat Inspection and Poultry Products Inspection acts, Huffman said.

"The burden rests with you to document these processes," Huffman said. "We are in the business to make money, and recalls affect our ability to do that.

"Huffman emphasized the importance of the new adulteration policy, which states that "there must be an affirmative finding that product is 'not adulterated' for it to bear the mark of inspection.

"In other words, Huffman explained, "We're not in a mode of 'don't ask, don't tell.' We're in a mode of 'must ask, must tell.'

”It is also important to constantly seek more knowledge, Huffman told The Meatingplace.com.

"One thing processors can do is attend courses," he said. "Also, understand regulations to protect public health.

'Another part of reducing illness is consumer education, Huffman said. For example, USDA's listeria risk assessment rated non-heated hot dogs as having the highest risk of contamination in the 20 categories of foods that were tested. When hot dogs are reheated, the risk for contamination drops to one of the lowest among the foods tested. However, up to 14 percent of consumers eat hot dogs without first reheating them.

"No one can tell what a new administration is going to do, but we hope they'll continue the consumer education that's been done in the past," Huffman said.

Other highlights from day one of the short course included:·

Thermal Processing Characteristics of Meat: Lynn Knipe, Processed Meats Extension Specialist at Ohio State. Knipe broke down the "big three" components of most RTE meat products: moisture (60 percent to 75 percent); protein (10 percent to 20 percent); and fat (4 percent to 22 percent). These ingredients affect how the product performs during thermal processing, but moisture is probably the most important contributor to how a product reacts to heat or chilling," Knipe explained.

· Fat has a lower heat capacity, meaning that it requires less energy to raise and lower its temperature, but its lower conductivity means that temperature changes in high-fat products take more time. Knipe also stressed that smaller, consistent pieces are important for a good result from processing. Increased product density boosts conductivity, decreasing the time needed for the product to chill or heat.

· Microbiology of Cooked Meats: Aubrey F. Mendonca, Department of Food Science and Nutrition at Iowa State University, said that the days of loading a meat product with salt or phosphates to kill pathogens are long gone. Nowadays, consumers are increasingly concerned with quality. "You can't just bombard a piece of meat and boast we've got the safest meat," Mendonca pointed out. "Consumers just won't touch it."

· But incidents of deadly pathogens, such as salmonella, E. coli or listeria, can't just be ignored. How can processors preserve quality and safety? The answer, Mendonca said, is hurdle technology, setting up multiple barriers to prevent pathogen from showing up in the final product. For example, ham processors products might use salt, nitrite and phosphates as one barrier, heat and smoke as the second barrier and vacuum packing as the third barrier. It is doubtful that any organisms will make it past the third barrier, but if they do, the final barrier of refrigeration will obliterate them.·

"This does not overwhelm a product with a chemical," Mendonca said.

"Microorganisms cannot make it past that many barriers." Mendonca also emphasized the danger of sublethal heat treatment, in which pathogens only partially destroyed by heat. Undetectable in even rigorous tests, they take a few days to recover. In that time, the supposedly pathogen-free meat may have made it to the consumer. Careful processing and "doing a good job the first time" should reduce the problem of heat-injured pathogens, Mendonca said.

This article reprinted with permission from Meat Marketing & Technology.

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