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

• Computational model was developed to predict heat and mass transfer considering sample shrinkage and porosity.
• Model is capable of predicting shrinkage, density and porosity of sample.
• Model can be used to study local moisture and temperature profiles within the sample at any time instance.

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.