Emerging Technologies for Food Processing, 2nd Edition

11.4. Determination of Moisture and Solid Diffusion Coefficients

The shape and size of the food being osmotically dehydrated varies considerably from application to application. The common shapes are slab, cylinder, cube, and sphere. Methods for estimating diffusion coefficients based on the geometry are presented here. Several methods have been reported in the literature for estimating diffusion coefficients for moisture and solute transport during osmotic dehydration, all based on solving Fick's second law for situation under consideration, which can be written for diffused moisture (M_r) and solid ratio (S_r), considering appropriate assumptions and boundary conditions (Crank, 1975; Rastogi et al., 2002):

11.4.1. Infinite Flat Plate

For a well-agitated, ...