Effect of overlapping chicken patties during air/steam impingement cooking on thermal inactivation of Salmonella Senftenberg and Listeria innocua

Ground chicken breast patties were inoculated, throughout, to contain 107 cfu/g of Salmonella Senftenberg or Listeria innocua. The inoculated products were cooked in a single layer or double overlaps in a pilot-scale air/steam impingement oven following storage in an equilibrium chamber that maintained the air at dewpoint. The cooking oven was maintained at 232degreesC, air circulation of 13 m(3)/min, and air moisture of 60 0 c (vol/vol). The total dwell (cooking) time was M to 5.0 min, including a dwell time of 1.0 min in the equilibrium chamber. The endpoint temperature in single-layered patties ranged from 53 to 68degreesC. The temperature between the overlapping surfaces was about 50% less than that at the center of single-layered patties. After being cooked, the Salmonella or Listeria population in the products was enumerated and compared among the patties that were cooked as a single layer and as overlaps. Salmonella and Listeria in the overlapped patties were about 6 logs more than that in the products that were cooked in a single layer. This information is useful for evaluating and controlling commercial meat cooking processes.