Thermal resistance for Salmonella enterica strains in Sous-vide chicken-and-vegetable patties

Abstract

Survival and thermal resistance of two Salmonella serovars inoculated onto chicken-meat and-vegetables patty were determined. Three Salmonella Enteritidis strains and one Salmonella Typhimurium isolated from regional chicken industries were inoculated to obtain levels of 108–109 CFU/g. Ten grams of patties, pH 6.45 and aw 0.95, were vacuum-packaged and heat-treated in a water bath at 65, 70 and 75 °C for different lengths of time. Salmonella survival cells were enumerated and D values were determined by linear regression and the Weibull regression model. Average D65 °C values ranged from 0.65 to 1.13 min across three strains. In contrast, the D65°C values calculated for one Salmonella Enteritidis strain were higher than those reported in the literature, 7.09 ± 0.14 min. For this strain D70 °C was 2.44 ± 0.04 min, and D75 °C was 0.53 ± 0.02 min. The times to obtain the target reduction of risk of Salmonella concentrations in 7 log CFU/g, at these temperatures were: 53.75 min, 14.62 min, and 3.98 min respectively. The calculated decimal-reduction temperature value was 8.88 °C. The results of this work may be used to guide food safety decision-making.