Measurement of the Water-Diffusion Coefficient, Apparent Density Changes and Shrinkage During the Drying of Eggplant (Solanum Melongena)

The aim of this work was to estimate shrinkage, apparent density changes, and the effectivediffusion coefficient of water, Deff, during eggplant drying. Drying experiments were performedusing a halogen moisture analyzer. This technology has several advantages overthe traditional methods reported in the literature, as it is quite inexpensive, requires lessenergy, and, in principle, can be used for many different types of foods. The experimentaldata were interpreted using a classical mathematical model that describes the transientmono-dimensional transport of water in food to estimate Deff. Under the experimental conditionsexamined, the Deff, was found to range from 1.13.10−10 to 5.65.10−10 m2/s. Shrinkagemodelling revealed a non-linear dependence of food sample volume on the food’s moisturecontent. In addition, while the apparent density of the food did not change appreciablyduring the first period of drying, a marked decrease was observed during the final dryingperiod.