Effect of temperature and volume changes on effective diffusivities of sucrose and NaCl during osmotic dehydration of vegetable tissue

Abstract

Osmotic dehydration of pumpkin (Cucurbita pepo, L.) fruits was carried out with binary solutions of sucrose and NaCl at different temperatures and solute concentrations. Water loss and solids gain kinetics were experimentally determined and fitted using a diffusional model. Pumpkins samples were considered as finite cylinders and the analytical solution of the unsteady diffusion equation was used considering the external resistance to the mass transfer negligible. The influence of shrinkage and temperature on the effective diffusion coefficients was also assessed in this work.