CHANGES IN STRUCTURE, DENSITY AND POROSITY OF POTATO DURING DEHYDRATION

Structural changes in potato during drying were studied by light microscopy. It was observed that the degree of shrinkage of potato during low-temperature drying is greater than at high-temperature drying. Shrinkage also affects the physical properties of materials, such as the density and porosity. In the early stage of drying the density increased as the moisture content decreased, reaching a peak and then decreased with further decrease in moisture content. The density at a given moisture content decreased with increasing drying temperature. A model was developed to represent the relationship between the density and moisture content. The total porosity increased steadily as moisture content decreased in the early stages of drying and then increased sharply towards the end of drying. The percentage changes in thickness, length and width of the potato samples during drying increased linearly with decreasing moisture content.