MATHEMATICAL MODELLING of MOISTURE, VOLUME and TEMPERATURE CHANGES DURING DRYING of PRETREATED APRICOTS

Authors


TÜBITAK Marmara Research Center Food & Refrigeration Technologies Department 41470 Gebze/Kocaeli, Turkey

Abstract

Simultaneous heat and mass transport in dehydration of apricots is presented. the moisture variation of apricots, pretreated with various combinations of sodium-meta-bisulphite and ethyl oleate solutions, was analyzed by Exponential and Page equations. Use of ethyl oleate in addition to sodium-meta—bisulphite as a pretreatment solution was observed to decrease drying times of apricots. the system of differential equations determining the unsteady-state temperature distribution was solved. Thermophysical properties were taken to be moisture dependent. the variation of volume upon drying (shrinkage) was introduced into the solution by taking space intervals to be variable in the apricot side while they were taken to be constants in the stone side. the dominant mass transfer mechanism was diffusion while diffusivity of water changed depending upon the pretreatment solution. Comparison between predicted and experimental data shows good agreement for both moisture and temperature variation of the apricots throughout the drying process.

Ancillary