29D-19 |
Predicting changes in temperature and quality in frozen foods undergoing variable boundary conditions during storage and distribution |
F. ERDOGDU1, B. A. Anderson2, and R. P. Singh2. (1) Food Engineering Dept., Mersin Univ., Ciftlikkoy-Mersin, 33342, Turkey, (2) Dept. of Biological & Agricultural Engineering, Univ. of California, Davis, 1 Shields Ave., 2030 Bainer Hall, Davis, CA 95616-5294 Increasing trade of frozen foods highlight an interest in quality changes (loss of nutrients, vitamins, textural changes, etc.) during storage and shipment. The most important parameter resulting in adverse quality changes is cumulative effect of time-temperature changes occurring due to the exposed boundary conditions during storage and distribution. The objective of this research was to develop a mathematical model to predict the change in temperature and temperature dependent food quality during storage and distribution and determine the effects of product composition for different boundary conditions. Temperature changes and quality losses for different shaped foods were determined using explicit finite difference models implemented in a computer program. Effects of product composition, different boundary conditions (temperature fluctuations, convective and radiative conditions) were predicted. Temperature changes were further related to the kinetics of quality attributes using available literature data. Beef patties of different compositions (low fat and high fat of different moisture content) packed in carton boxes were used during the experiments of different scenarios (starting with freezing the product). These scenarios included the temperature fluctuations in the freezer due to the operations of fans and then exposure to room temperature and sunlight for different times to simulate the shipment and conditions encountered at loading docks. The developed model predicted the temperature changes and quality losses with respect to different compositions and boundary conditions. Excellent agreement was obtained between predicted values and experimental temperature data. The results showed that the environmental time temperature changes dramatically influenced the responses of food products and hence the other quality changes. Computer-aided mathematical models can assist in predicting temperature profiles and quality changes with the known product composition and boundary conditions, similar to those obtained by using temperature sensors. However, reliable data in the selected quality attributes is necessary to improve on overall quality of a shipment.
Session 29D, Food Engineering: Thermal processes
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