Validation of processing parameters for the production of microbiologically safe cooked ready-to-eat and raw meat products

Recent outbreaks of foodborne illness have resulted in increased regulatory pressure on meat processors. Validation of production processes to determine their ability to produce microbiologically safe finished product has been emphasized. Control of pathogen growth in raw products and pathogen lethality during heat processing of cooked ready-to-eat (RTE) products are important. Cross contamination of carcass surfaces with bacteria, including pathogens such as Salmonella and Escherichia coli O157:H7, can occur during animal harvest. Sources of contamination include the digestive tract and hide of the animal and the processing environment. Raw meat products are not generally subjected to interventions during processing that reduce bacterial counts. Therefore, it is necessary to control the growth of bacteria on the product during processing. Control of product and/or processing environment temperature is generally the only available means to control bacterial growth. Control of bacterial growth in raw meat for use in the production of cooked RTE meat products is less important than in product to be sold in the raw state. Safety of cooked RTE products depends on proper cooking. Thermal processing parameters should be designed to result in a Salmonella lethality that meets or exceeds regulatory performance standards. Parameters of interest include oven temperature, product internal temperature, processing time and process humidity. The purpose of the studies performed was to determine the effects of environmental and product temperature on the growth of Salmonella and E. coli O157:H7 in raw meat products and also the effects of product temperature and process humidity on the lethality of surface inoculated Salmonella during the thermal processing of cooked RTE roast beef. Results suggest that meat processors can safely process raw meat products under a variety of conditions, ranging from 4.4ºC (40ºF) to room temperature (23.3ºC/74ºF) if the time of product exposure is considered relative to the product or environmental temperature. Furthermore, thermal processing of cooked RTE roast beef in the presence of humidity levels ranging from 30-90% resulted in an adequate Salmonella lethality when processed to an internal temperature of 62.8ºC (145ºF). Overall results provide parameters that can be utilized by meat processors to produce microbiologically safe finished products.