Shrinkage and porosity effects on heat and mass transfer during potato drying.

Fruits and vegetables are porous in nature and undergo pronounced shrinkage during convective drying
process. Therefore, shrinkage and porosity should be taken into consideration while predicting heat and
mass transfer. This work was conducted to study shrinkage and porosity changes along with simultaneous
heat and mass transport during the process. Potato slices were subjected to drying for 7 h at
62 �C. It was observed that shrinkage varies linearly with respect to moisture content and reduction in
radial dimension of potato slices was around 35%. Porosity undergoes rapid increase after attaining certain
moisture content in final stages of drying. The work was extended to study the influence of shrinkage
and porosity on heat and mass transfer. Simulated results were validated with experimental values. This
model can be employed to predict temperature, moisture, density profiles and to study shrinkage and
porosity of various fruits and vegetables.