Processed Meat Thermal Processing Food Safety - Generating D-Values for Salmonella, Listeria monocytogenes, and Escherichia coli.

Abstract

USDA, FSIS thermal processing guidelines (e.g. Appendix A for cooked beef, roast beef, and cooked corned beef, and Time-Temperature Tables for Cooking Ready-to-Eat Poultry Products) are widely used as validation support for cooking processes, but these procedures were developed and validated only for in a limited number of products. To determine the extent to which Appendix A can safely be applied to other pathogens and products, a study was conducted to compare the thermal-death times of , and shiga toxin-producing (STEC) in model products representing roast beef, turkey breast, and boneless ham. Raw batter for each of the 3 products was inoculated with 8 log CFU/g of a multi-strain mixture of , or STEC. One-gram portions of inoculated roast beef, turkey breast, or ham batter were flattened into a thin film in moisture-impermeable pouches, vacuum-packaged, and heated at 54.4, 60.0, 65.6, or 71.1°C in a water bath. Triplicate samples were removed at predetermined time points and enumerated for surviving pathogens. The time needed to yield a 6.5-log reduction of and STEC at 60.0, 65.6, or 71.1°C for the three product types was comparable to the times prescribed by USDA, FSIS Appendix A for inactivation; however, at 54.4°C similar inactivation levels were not observed. showed greater thermotolerance than and STEC for all 3 product types. These data suggest that current USDA, FSIS thermal processing guidelines are acceptable tools for ensuring the safety of cooking processes at 60.0°C or higher to inactivate and STEC in the product types, but longer dwell times may be necessary to yield comparable log reduction of .