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 Salmonella 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 Salmonella, Listeria monocytogenes, and shiga toxin-producing E. coli (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 L. monocytogenes, Salmonella, 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 Salmonella 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 Salmonella inactivation; however, at 54.4°C similar inactivation levels were not observed. L. monocytogenes showed greater thermotolerance than Salmonella 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 Salmonella and STEC in the product types, but longer dwell times may be necessary to yield comparable log reduction of L. monocytogenes.

Efficacy of household washing pre-treatments and cooking methods for reduction of Listeria monocytogenes in artificially contaminated chicken offal

“…This indicates the effectiveness of heat treatment on the elimination of microbial in food. Wong et al (2011) researchers also reported similar findings which cooking treatment improved lethality on pathogens in ground beef (Guo et al, 2006;Yoon et al, 2013), egg (Fang and Huang, 2014), steak, hamburger or meat strips (Lahou et al, 2015), poultry-based meat products (Roccato et al, 2015), and processed meat (McMinn et al, 2018).…”

Sous-vided Restructured Goat Steaks: Process Optimized by Thermal Inactivation of Listeria monocytogenes and Their Quality Characteristics

“…In previous study, the D-values at 60℃ of L. monocytogenes was 5.61 min (Murphy et al, 2004). The D-values at 65.6℃ and 71.1℃ of L. monocytogenes in uncured roast beef were 7.25 and 0.34 min, respectively, using water bath (McMinn et al, 2018). In another study, the resistance of five-strain L. monocytogenes cocktails was estimated in chicken breast piece and cooked in water bath.…”

“…However, one of the most heat resistant bacteria is L. monocytogenes. The D-value at same temperature of L. monocytogenes had higher than those of Salmonella and E. coli (McMinn et al, 2018). Thermal treatment times guidance and requirements for raw meat have been depended on the criterion and globally accepted parameters of heat treatment.…”

Validating a Method to Ensure the Destruction of Salmonella on Product Surfaces During Impingement Cooking

“…Most published pathogen lethality studies use inoculated samples that have a high water activity (i.e., a w at >0.97) to measure the D-and z-values. In these studies, the inoculated meat samples are usually packaged in moisture-impermeable plastic film and then immersed in hot water for heating (O'Bryan et al, 2006;McMinn et al, 2018). As such, these experiments seldom account for the increased heat tolerance of desiccated pathogens resulting from surface dehydration that often occurs when products are cooked in forcedair convection ovens.…”

“…Cooking meat products in forced-air convection ovens such as impingement ovens is essentially a high-temperature drying process (Skjöldebrand, 1980). Based on previous research regarding drying phases during cooking, we hypothesized that during the wet-surface phases of a cooking process-the preheat and constant-rate drying periods-the inoculated Salmonella on the product surfaces would be fully hydrated and thus be susceptible to the standard D-and z-values from the literature for hydrated Salmonella (O' Bryan et al, 2006;McMinn et al, 2018). To test this hypothesis, we designed thermal processes for this study that used hydrated surface lethality (HSL) steps that exposed the product surfaces to lethal time-temperature conditions during the saturated-surface, constant-rate drying period.…”