Actual and computer simulated heating rates during the baking of the turkeys
[Thesis]
H.-C. Chang
J. A. Carpenter
University of Georgia
1997
140-140 p.
Ph.D.
University of Georgia
1997
A need for an accurate indication for reaching the endpoint temperatures in the turkey and stuffing, which would provide more safety against pathogens and prevent overcooking of stuffed or unstuffed turkeys by consumers, induced this study. Baking time was 155 min plus 11 min per kg of unstuffed bird, and 200 min plus 8.8 min/kg for stuffed birds. It is unreliable to determine cooking endpoint with baking time based on bird's weight. Continuous temperature monitoring revealed that wing joint and the stuffing were the slowest heating points during the baking processing. However, when birds were removed from the oven and held 20 min on the open oven door after turning off heat, internal temperature at wing joint increased slightly before falling, and accumulated adequate heat lethality against Salmonella. To ensure proper heat treatment, the endpoint temperature of stuffing should be monitored with a thermometer or an accurate temperature indicator to determine that temperature of 74C is attained. Mathematical models were developed to predict the temperature histories of unstuffed turkeys, (averaging 5.9, 6.8, 8.6, 9.5, and 10.4 kg) during baking in an electric oven without forced air movement The finite element method was used to solve simultaneous unsteady state heat transfer equations. Numerical simulation results agreed with experimental data. Predicted temperatures were within 1.33, 1.47, and 1.22C of experimental values in the breast, thigh, and wing joint, respectively. Simulations revealed that initial temperatures strongly influenced cooking time in this study. Cooking birds at a higher oven temperature (176C) resulted in a shorter cooking time, but it might potentially produce over-cooked turkeys. Cooking turkeys at a lower oven temperature (149C) required longer cooking time, but it might not have adequate accumulating heat to inactivate pathogen, Salmonella.