the effect of drying kinetic on shrinkage of potato slices

Objective: potato is the fourth important food crop after wheat, rice and maize. shrinkage of food materials has a negative consequence on the quality of the dehydrated product. the main objective pursued in this paper is to investigate the shrinkage amount of potato slices during drying process using vacuum-infrared method. methods: in this work, the effect of the infrared radiation powers (100, 150 and 200 watt) and absolute pressure levels (20, 80, 140, 760 mmhg) at different thickness (1, 2 and 3 mm) on bulk volumetric shrinkage were investigated. results: data analysis showed that shrinkage percentage decreased with decrease of sample thickness and increase of infrared power. it was found that either thickness or infrared power had any significant effects (p < 0.01) on shrinkage of potato slices in this drying system. the regression model is a three-variable linear that coefficient of determination is 0.532 and implies that the model can explain 53.2 % of the volume ratio changes.