Analytical solution for food-drying kinetics considering shrinkage and variable diffusivity

In this work, an analytical solution of a mass transfer equation for drying considering both shrinkage and variable diffusivity was proposed. Experimental drying kinetics for mango slabs at different air temperatures (50, 60 and 70 °C) and 2.5 m s−1 of air velocity were obtained in order to fit proposed model by means of non-linear regression with four different degrees of complexity. Results showed that proposed model is able to reproduce accurately experimental drying kinetics, and that shrinkage must be considered as averaged or moisture-dependent lengths for water diffusion so as to obtain reliable values for effective diffusivity.