Predictive Modelling of Osmotic Dehydration of Food Materials

Duduyemi Oladejo, Oluoti K.O, Adedeji K.A., Raji N.A.

Abstract— During osmotic dehydration of food materials, water and/or other substances are removed from the material with molecular infiltration; shrinkage follows depending on the extent of net mass loss. Molecular diffusion is one of the generally accepted and necessary tools for finding simple predictive models that describe mass transfer across plant membranes. The mass transfer resistances across a semi-permeable medium were investigated with Fickian molecular diffusion model and a combined molecular and convective model. The effects of intercellular and trans-membrane resistances studied with two-parameter kinetic models described the behaviours of solute impregnation and dewatering processes of osmotic dehydration.  Predicted depth of solute impregnation in an imaginary food matrix was 4.0 mm with satisfactory deduction that combined molecular and convective model is a better description of the transport models. The solutions of the models also revealed that concentration gradient across the membranes depends linearly on process variables and the influences of membranous resistance were not negligible.