HEAT AND MOISTURE TRANSFER IN COMPOSITE FOOD THEORETICAL-ANALYSIS OF INFLUENCE OF SURFACE CONDUCTANCE AND COMPONENT ARRANGEMENT

Heat and moisture transfer in composite bodies undergoing drying was s imulated using a previously developed mathematical model which include d the chemical potential of moisture as a mass transfer potential. Com posite bodies included layered cylinders and concentric spheres consis ting of a starch granule hydrate (H) and a hydrate of starch granules- sucrose 3:1 mixture (S). The influence of the following factors on hea t and moisture transfer was examined: convective surface mass transfer conductance, initial moisture, and component arrangement. The three f actors significantly influenced moisture transfer while they had sligh t influence on heat transfer. Overall drying rate of each composite bo dy was influenced interactively by moisture fluxes, which were caused by a surrounding drying medium and by a mass transfer potential differ ence across the interface of H and S.