On the Study of Osmotic Dehydration and Convective Drying of Cassava Cubes

Abstract

This paper aims to study the hybrid process of osmotic dehydration and convective air drying of foods. Emphasis has been put on cassava cubes (Manihot esculenta Crantz.). Convective drying kinetics of fresh and osmotically dehydrated cassava cubes was evaluated at the following hot air-drying conditions: temperature 50°C, velocity 1.35 m/s, and absolute humidity 0.060 dry water/g. Experimental results of the moisture loss, solids gain, and incorporation of sodium chloride are shown and analyzed. For estimation of the effective mass diffusion coefficient, experiment data of average moisture content of cassava cubes (fresh and osmotically dehydrated) was fitted to the simplified Fick model and a good agreement was obtained. The effective mass diffusivity of the osmotically dehydrated cassava cube was 2.75 x10-10 m2/s and to fresh cassava cubes 5.45x10-10 m2/s.