ABSTRACT
Drying is a heat and mass transfer process to remove water or another solvent by evaporation, in most of the cases, from a solid, semisolid, or liquid. Solvent removal by sublimation takes place in freeze drying, while in osmotic dehydration, water is removed from a solid material as liquid due to osmotic pressure and hence concentration difference. It is used in the food, agricultural, ceramic, chemical, pharmaceutical, pulp and paper, mineral, polymer, and textile industries. Drying duration depends on the nature of the product, the drying method or technique applied, and the drying conditions. Drying is an operation with a heavy demand for energy, contributing ~12% of the total energy used in industrial sectors worldwide (Misha et al., 2012). According to Bórquez et al. (1999), drying of food materials is not just a heat and mass transfer process but also a technological process that has a signicant effect on product quality as it contributes to preservation and often to the improvement of the technological properties of products.
