Survival of Salmonella and the surrogate Enterococcus faecium in cooking of moisture enhanced reconstructed comminuted chicken patties by double pan-broiling.

This study compares kinetic parameters of Salmonella and Enterococcus faecium in moisture enhanced, reconstructed comminuted chicken patties prepared with different pump rates during double pan-broiling with various set-up temperatures. Fresh 1.5-kg chicken breast meat was course grounded, inoculated with S. Typhimurium and Tennessee, or E. faecium, followed by adding NaCl (2.0%) + Na-tripolyphosphate (0.5%) solutions to achieve pump rates of 1%, 5%, or 11.1%. Meat samples were manually manufactured into patties with the thickness of 2.1 cm and diameter of 10.4 cm. Patties were packaged with polyvinyl chloride films in the foam-tray stored at 4°C for 42 h before double pan-broiling set at 200°, 300°, or 425°F for 0 to 420 s. Counts of pathogens were analyzed on xylose-lysine-Tergitol-4 and bile esculin agars with tryptic soy agar layers. Microbial data and kinetic parameters (n = 9, United States Department of Agriculture [USDA]-Integrated-Predictive-Modeling-Program/USDA-Global-Fit software) were analyzed by the Mixed Model Procedure (SAS). Double pan-broiling reduced >5-log CFU/g (P < 0.05) of Salmonella after 360 (200°F), 180 to 225 (300°F), and 150 to 165s (425°F), and of E. faecium after 270 s (300°F), and 180 s (425°F) across all samples. D-values (Mafart-Weibull model) of Salmonella and E. faecium in 1% moisture enhanced samples cooked at 200 to 425°F (102.7-248.2 and 115.5-271.0 s) were lower (P < 0.05) than 11.1% samples (119.8-263.7 and 122.5-298.3 s). Salmonella were more susceptible (P < 0.05) to heat than E. faecium. "Shoulder-time" (Buchanan-Two-Phase model) of Salmonella cooking at 200° to 425°F increased (P < 0.05) from 82.3-229.0 to 116.6-246.2 s as pump rate increased from 1 to 11.1%, whereas this phenomenon was not shown for E. faecium. Results indicate that Salmonella were resistant to heat in chicken patties with greater pump rate. E. faecium can be used as a surrogate for Salmonella to validate thermal inactivation in chicken products.