Process lethality and product yield for chicken patties processed in a pilot-scale air-steam impingement oven

Chicken breast patties were processed in a pilot-scale air-steam impingemen t oven to a patty center temperature of 55 to 80 degreesC. Thermal processi ng was conducted at an air temperature of 149 degreesC, an air velocity of 7 to 13 m(3)/min, and a wet bulb temperature of 39 to 98 degreesC. From the rmal histories, the total process lethality of the patties was calculated f or Salmonella spp. and Listeria innocua using the previously published z-va lues. The effect of product temperature, wet bulb temperature, and air velo city on process lethality was analyzed using a regression model. The proces s lethality of Salmonella spp. and L. innocua in the cooked chicken patties was correlated to the patty center temperatures and cooking conditions. Th e process lethality was strongly correlated to product temperature and was affected by cooking conditions. Process lethality started to increase rapid ly at the product temperature around 67 degreesC. Regression analysis was u sed to correlate the product yield with cooking conditions. Depending on ai r velocity, product yield decreased 10 to 14% with increasing endpoint temp erature from 55 to 80 degreesC and increased 2 to 9% with increasing wet bu lb temperature from 39 to 98 degreesC. The effect of air velocity on the yi eld interacted with product temperature and wet bulb temperature.