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 impingement oven to a patty center temperature of 55 to 80°C. Thermal processing was conducted at an air temperature of 149°C, an air velocity of 7 to 13 m 3 /min, and a wet bulb temperature of 39 to 98°C. From thermal histories, the total process lethality of the patties was calculated for Salmonella spp. and Listeria innocua using the previously published z-values. The effect of product temperature, wet bulb temperature, and air velocity on process lethality was analyzed using a regression model. The process lethality of Salmonella spp. and L. innocua in the cooked chicken patties was correlated to the patty center temperatures and cooking conditions. The process lethality was strongly correlated to product temperature and was affected by cooking conditions. Process lethality started to increase rapidly at the product temperature around 67°C. Regression analysis was used to correlate the product yield with cooking conditions. Depending on air velocity, product yield decreased 10 to 14% with increasing endpoint temperature from 55 to 80°C and increased 2 to 9% with increasing wet bulb temperature from 39 to 98°C. The effect of air velocity on the yield interacted with product temperature and wet bulb temperature. Des boulettes de viande de poulet sont cuites dans un four a impact afin que la temperature interne atteigne 55 a 80°. La temperature de l'air est de 149° et la vitesse de 7 a 13 m 3 /min. L'effet de ces conditions de cuisson sur la letalite de Salmonella spp et Listeria inocua est etudie. On constate que la letalite est fortement liee a la temperature du produit et est influencee par les conditions de cuisson: ainsi, on constate que la letalite augmente brusquement quand la temperature interne atteind 67°C.