Kinetics of osmotic dehydration under vacuum

Abstract

Osmotic dehydration under vacuum was studied. The effect of vacuum application was explained on the basis of the diffusional osmotic transport parameter, the mass transfer coefficient and interfacial area. A mathematical model is proposed to explain the mechanism of water transport during osmotic dehydration based on a more fundamental parameter, the osmotic pressure. Osmotic pressure ratios were calculated for dehydration under atmospheric conditions and under vacuum. The increased osmotic pressure due to vacuum application was also calculated. The rate of mass transfer during osmotic dehydration of food increases under vacuum. The vacuum applied affects only the rate at which the equilibrium is attained and not the equilibrium osmotic pressureper se.