17H-10 |
|
A. E. Watkins1, B. P. MARKS1, A. M. Booren2, E. T. Ryser2, and A. Orta-Ramirez2. (1) Dept. of Agricultural Engineering, Michigan State Univ., 210 A.W. Farrall Hall, East Lansing, MI 48824-1323, (2) Dept. of Food Science & Human Nutrition, Michigan State Univ., 3385 Anthony Hall, East Lansing, MI 48824-1225 Convection cooking is an important method for commercial processing of ready-to-eat meat products. As impingement ovens become increasingly common in the meat processing industry, more detailed information on the relationships between oven conditions and product characteristics are needed in order to optimize process design and operation. Our objective was to develop a computer model for predicting cooking yield (due to moisture and fat transport), temperature profile, and Salmonella inactivation during impingement cooking of ground and formed meat products. A computer model for impingement cooking was developed using the finite element method. Coupled heat and mass transfer was modeled with the mass transfer portion comprised of both moisture transport and fat transport. The condensing-convective boundary conditions were modeled by treating condensation as a true mass transfer process, rather than by using "effective" convection coefficients. A Salmonella inactivation model was integrated into the cooking model. The heat and mass transfer model was validated using data collected from an industrial moist-air impingement oven at 121-232oC, 50-86% air moisture content, and 12-22 m/s gas (exit) velocities. Salmonella inactivation was validated using data from a pilot-scale impingement oven. The model satisfactorily predicted the results observed in the commercial oven. Patty surface temperature increased with increasing oven steam fractions. The standard error of prediction for center temperature (n=54) was 5oC. Yield estimations neglecting fat transfer (n=54) were shown to overestimate cooking yield by up to 10%. These additional losses were accounted for by incorporating fat transport into the model as a second mass transfer component. The cooking model can be used by meat processors to estimate the effects of changes in oven settings on product yield and safety. This may encourage processors to adapt current cooking strategies to maximize yield and throughput while continuing to maintain product safety.
Session 17H, Food Engineering: Thermal processes
|