Osmo-convective Dehydration of Fresh Foods: Theory and Applications to Cassava Cubes

Abstract

This chapter focuses on the hybrid process of osmotic dehydration and convective air drying of foods. Emphasis has been done to cassava cubes (Manihot esculenta Crantz.). The fresh cassava cubes had a water activity content of about 0.954, 60.45% moisture on a wet basis, 2.27% sucrose, and 0.13% sodium chloride on a wet basis. Herein, the kinetics of osmotic dehydration of cassava cubes were studied under an optimized operating condition of the convective drying kinetics of fresh and osmotically dehydrated cassava cubes which were evaluated at different drying conditions. Under mathematical point of view, different lumped approaches are used to estimation of average effective mass diffusivities (moisture and solids). Transient results of moisture loss, solids gain, sodium chloride, and sucrose incorporation, and moisture content are presented, compared with experimental data, and discussed. The hybrid process has generated a dry product with 11% moisture, 16.89% sucrose, and 5.94% sodium chloride on a dry basis at better operation conditions. The product obtained from the cassava cubes hybrid process can be used in the food production at cassava base.