Determination of diffusion coefficients in volume-changing systems—Application in the case of potato drying

Abstract

This work was based on a modified Crank approach in order to determine the diffusion coefficient in systems where volume changes occur during dyring. The modified model was applied to the case of potato drying, for both raw and blanched potatoes, at two temperatures: 60 and 80°C. The degree of volume change (shrinkage) was different for raw and blanched potatoes, but only small differences have been observed for the diffusion coefficient of reference, which was evaluated at 2·25 (± 0·13) × 10 −10 m 2/s for raw potatoes and 2·48 (± 0·28) × 10 −10 m 2/s for blanched potatoes.