Effect of beef product structure and sublethal cooking history on Salmonella thermal inactivation.

摘要

The effect of beef product structure and sublethal heating during cooking on Salmonella thermal resistance has not been reported, and its importance is not known. Therefore, the objectives of this study were: (1) To determine the relationship between thermal resistance of Salmonella and degree of grinding, and (2) To determine the effect of cooking profiles and sublethal heating on Salmonella thermal inactivation in whole-muscle beef.; All samples were inoculated with a marinade containing an eight-serovar Salmonella cocktail (∼108 CFU/mL). For objective 1, samples (whole-muscle, coarse-ground, fine-ground, or pureed) were packed into sterile brass tubes, sealed, and held in a water bath at 60°C for 8-11 durations (at 30 s intervals). For objective 2, small, sterile beef steaks were subjected to 6 different cooking schedules in a moist-air convection oven until 6.5 log reductions in Salmonella were predicted by traditional log-linear inactivation kinetics applied to real-time internal temperature data.; Results showed that thermal resistance of Salmonella was higher (P0.0001) in whole-muscle than in ground products, however, there were no differences among the other three product types. Also, longer exposure of Salmonella to sublethal heating during slow cooking profiles significantly reduced (P0.05) subsequent inactivation.