Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/24/2004
Publication Date: 9/14/2004
Citation: Juneja, V.K. 2004. Thermal treatments to control pathogens in muscle foods. Meeting Abstract.
Technical Abstract: The use of heat to inactivate foodborne pathogens is a critical control point and the most common means of assuring the microbiological safety of processed foods. A key to optimization of the heating step is defining the target pathogen's heat resistance. Sufficient evidence exists to document that insufficient cooking, reheating and/or subsequent cooling are often contributing factors in food-poisoning outbreaks. Accordingly, the objectives of the studies were to determine the heat treatment required to achieve a specific lethality for foodborne pathogens in cooked meat. The effects and interactions of heating temperature, pH, sodium chloride (NaCl), sodium pyrophosphate (SPP), sodium lactate (NaL), and sodium diacetate (Na diac.) on the heat resistance of Clostridium botulinum, Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella spp. in 75% lean ground beef and/or ground turkey were examined. Thermal death times were determined in filtered stomacher bags using a water bath. Decimal reduction times (D-values) were calculated by fitting a survival model to the data with a curve fitting program. The D values were analyzed by second order response surface regression for temperature, pH, NaCl, SPP, NaL, and Na diac. Incorporation of the above food formulation factors (multiple barriers) increased the sensitivity of the pathogens to heat, thereby reducing heat requirements and ensuring the safety of ready-to-eat food products. Mathematical models describing the combined effect of the multiple factors on the thermal inactivation of the above foodborne pathogens were developed. The models can predict D-values for any combinations of temperature, pH, NaCl, SPP, NaL, and Na diac. that are within the range of those tested and have been incorporated into the USDA-Pathogen Modeling Program. Predictive inactivation kinetics (thermal death) for foodborne pathogens should aid in evaluating the safety of cooked products and are being used as building blocks for microbial risk assessment. The models currently have and will continue to have substantial practical importance to food processors of cooked meat.