30F-9 |
Heat and mass transfer for MAP systems applied to nonrespiring foods |
R. J. SIMPSON, C. A. Acevedo, S. F. Almonacid, and C. A. Cortés. Procesos Químicos, Biotecnológicos y Ambientales, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, 5632, Chile In recent years consumer demand for fresh and chilled foods have been increased, which has led to a diversification in the range of products packaged in modified atmospheres. Even though technological advances have been made, most of the Modified Atmosphere Packaging (MAP) development has been empirical. Mathematical models based on heat and mass transfer is a powerful tool for an optimal design of MAP systems. The aim of this research study was to develop a mathematical model to predict heat and mass transfer phenomena in modified atmosphere packaging for non-respiring foods. A mathematical model was developed to predict temperature and gas concentrations within food material and headspace exposed to variable ambient temperature. The model was applied to MAP system containing CO2, O2, N2 and H2O, with non-respiring foods products. The average convective heat transfer coefficient was determined as a function of headspace height and the convective mass transfer coefficient was estimated utilizing the analogy between heat and mass transfer. The partial differential equations system was solved using an explicit finite difference scheme. The validation study was done using gelatine. The experimental results confirmed the proposed mathematical model and its numerical solution. The simulation results were in good agreement with the observed temperatures and gases histories. The prediction errors obtained in the validation study were under 5% and not statistically significant differences (P<0.05) between the experimental and predicted values was found. The mathematical model can be used not only to determine the package specifications for a given product and given ambient temperatures, but also to predict the amount of time required for the packaging system to attain the designed optimum conditions.
Session 30F, Food Engineering: Transport processes and kinetics
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