Our goal was to look at different treatments that might be used to decontaminate the surface of cooked products to ensure that Listeria was killed and it had very little opportunity to grow after that, said Dr. Jimmy Keeton, professor with the department of animal science at Texas A&M University. Listeria grows at refrigerator temperatures.
Foodborne listeriosis is most commonly associated with ready-to-eat products such as frankfurters and hot dogs, lunch meat, smoked fish and certain types of soft cheeses, Keeton said.
L. monocytogenes is considered a serious threat because -- even though it doesn't affect that much of the population -- when it does strike, it can be deadly. In humans, listeriosis can cause flu-like symptoms, meningitis, spontaneous abortions and prenatal septicemia, said Keeton. About 20 percent of listeriosis cases are fatal.
Theres a real concern about from the time ready-to-eat products are cooked until the time they are packaged that they not become contaminated with pathogens, specifically L. monocytogenes, he said.
When these products are cooked, they are pasteurized and the Listeria is killed. Assuming the product is cooked adequately, the risk of contamination comes from the surface, he said.
If the product is contaminated after cooking, there is a risk in eating that product without proper reheating. Some luncheon meats, such as bologna, are routinely not cooked before eating.
Research had already shown that adding substances such as lactic acid and sodium lactate created microbiological "hurdles" to organisms such as Listeria, Keeton said. But still, these were not considered entirely effective against the regrowth of the organism.
However, acidified calcium sulfate an organic acid, ca
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Contact: Dr. Jimmy Keeton
jkeeton@tamu.edu
979-845-3936
Texas A&M University - Agricultural Communications
2-Jan-2003