Date of Award
Doctor of Philosophy
Mary Jo Hitchcock
Grayce E. Goertz, Betty L. Beach, John H. Gibbons
Energy utilization characteristics for commercial food service equipment were determined to provide data to establish the cost of energy in the preparation of food products. Twenty pounds of frozen pre-cooked breaded chicken quarters were cooked to an end point temperature of 180°F using a deep fryer, a braiser, a two-pan bake oven, and a convection oven.
Kilowatt-hour readings were made to measure energy consumption of each piece of equipment. An alternate technique was developed to estimate energy consumption of each piece of equipment by using energy ratings in combination with measuring the on-time of the thermostat signal light. The energy consumption data from the meters were compared to the energy consumption data as estimated by the thermostat timing technique.
A seven-member taste panel evaluated quality characteristics of color, tenderness, juiciness, flavor, and overall acceptability of the chicken quarters cooked in the four pieces of equipment. For the quality characteristic of color, the chicken cooked in the bake oven was judged by the panel as lower in desirability than chicken cooked in the other equipment. Chicken cooked in the four types of equipment was similar for each of the other quality characteristics.
Pearson product-moment correlation coefficient data indicated that no significant relationship existed between cooking kilowatt-hour (kwh) consumption and sensory acceptance scores.
A linear relationship existed between cooking time and on-time of the thermostat signal light. The predictability percentage from cooking time to on-time of the thermostat signal light was: deep fryer 38.7, braiser 98.8, bake oven 88.8, and convection oven 53.0. This indicated that cooking time can be used to predict the on-time of the thermostat signal light with some degree of accuracy for the braiser and bake oven.
The braiser was found to be most energy intensive for warm-up and least energy intensive for cooking the chicken. The deep fryer was least energy intensive for warm-up and most energy intensive for cooking. For total kwh consumption, the braiser was highest and the convection oven lowest.
The deep fryer required the least amount of time to warm-up, and the braiser the most time. The braiser cooked the chicken in the shortest amount of time, whereas the bake oven required the longest time. The deep fryer needed the least amount of total time while the bake oven required the most. This information could be important in scheduling of equipment use for food preparation to conserve energy and reduce operating costs.
The estimation of energy consumption from the on-time of the thermostat signal light as predicted from cooking time can be used by any operator of similar electrical commercial food service equipment. The kwh consumption can then be converted to BTU's and placed on the standardized recipe to provide energy utilization information for the planning of food preparation.
Romanelli, Frank, "Energy Utilization Characteristics of Selected Electrical Commercial Food Service Equipment. " PhD diss., University of Tennessee, 1976.