Food safety before cooking - EFR 6-11

Food safety education is a fundamental part of good nutritional practices. While we stress that foods need to be cooked thoroughly, the following report emphasizes that both large operations and the consumer need to follow good practices PRIOR to cooking the food.

Excerpted from FOOD CHEMICAL NEWS, FEBRUARY 5, 1996, Page 12

While cooking can reduce the risk of food poisoning, ignoring other factors would be a mistake, warned researchers in a study on pork products in institutional settings.

In the study, reported in Dairy, Food and Environmental Sanitation, "Evaluation of Microbial Hazards of Pork Products in Institutional Foodservice Settings - Part I," Nancy Brown of Iowa State University and other researchers looked at the processing of breaded pork loins starting from the raw loins to the ready- to-eat product served in three dining centers. Time and temperature measurements, meat samples and samples of different surfaces were taken at several points in the process.

The study found that the raw pork used by the dining centers had levels of bacteria below those usually found in raw meat. The low levels were directly linked to good manufacturing practices during slaughter, the study said. Clostridium perfringens and Yersinia enterocolitica bacteria as well as viruses were not detected in any of the samples at any step during processing, but Salmonella spp. and Staphylococcus spp. were consistently found.

The researchers also found that proper refrigeration controlled the growth of harmful bacteria and that cleaning procedures were adequate, with few organisms detected in swabs taken from pans prior to baking and no organisms found at the end of service.

"Frying and baking were effective in destroying microbial contaminants in the product, even though there was evidence of temperature abuse of the cutlets during refrigerated storage before baking, and mean product temperatures were below [140 degree F] at the end of service," they reported. The only organism detected at the end of service was Staphylococcus aureus. The report suggests that this bacteria may have been introduced by workers and their utensils during transfer of product from baking pans to serving pans or during service.

While proper cooking was the most crucial step for preventing foodborne illness, the study stressed that this step should not be a reason to ignore good practices prior to cooking. The study noted, "Failure to follow federal guidelines for time and temperature could result in a hazard to the consumer, especially if the holding temperature following the cooking step is below [140 degree F]." The study pointed out that leaving cooked foods at room temperature was the most important factor (56% of the outbreaks) and inadequate cooking the least important factor (4%) contributing to outbreaks of foodborne illnesses from foods prepared in foodservice establishments from 1973 to 1982. The researchers concluded, "We have shown that proper storage, transportation, handling and cooking are essential to maintain the safety of perishable meat products like pork cutlets."

The report recommended additional studies on the role of food handlers in introducing contaminants during processing as well as looking at the effect of industrial sanitizers on the prevalence of microorganisms such as Escherichia coli O157:H7 in foods during preparation.