14A-39

S. WICHCHUKIT¹, S. E. Zorrilla, and R. P. Singh. (1) Department of Biological and Agricultural Engineering, University of California at Davis, One Shields Avenue, Davis, CA 95616

Mathematical models may be used to predict the internal temperature of meat patties during double-sided contact cooking. The contact heat transfer coefficient, h, is an essential parameter for a reliable model. This coefficient is the reciprocal value of the thermal contact resistance that appears between the grill surface and the patty surface because of an imperfect contact between two solids. Our objectives were to study the behavior of the heat transfer coefficient along the cooking time under and the effect of factors such as plate temperatures, gap thickness between plates, and the surface characteristics of the top and bottom plates on the coefficient values. Frozen meat patties (-30°C) from a commercial manufacturer were used. Cooking process was carried out in a commercial-scale clamshell grill (Taylor, Rockton, IL). The h values were calculated as a function of heat flux and the difference between grill and patty surface temperatures. The heat flux was measured using a thin film heat flux sensor HFS-3 (Omega Eng., Inc., Stamford, CT). A T-type thermocouple was used to determine the patty surface temperature while the grill surface temperatures were determined using K-type thermocouples installed in the grill. A split-split plot design with six replicates was conducted. Analysis of variance (ANOVA) was carried out with SuperANOVA 1.1 software. The heat transfer coefficient values were in the range of 250 to 650 W/m²°C. The h value increased at the beginning and then decreased to a constant value towards the end of the cooking process. ANOVA table indicated that there are some significant differences in the values for the factors considered in the studies, with the surface characteristics of the top and bottom plates being the most dominant.