Experimental characterization and modeling of thin-layer drying of mango slices

Convective air drying characteristics of mango slices at different drying temperatures (60°C, 70°C and 80°C), at an air velocity of 0.5 m/s and for constant sample thickness (3 mm) were investigated. Results indicated that drying took place in the falling rate period. Drying time decreased considerably with increased drying temperature. Three mathematical models; namely, Newton (Lewis), Henderson and Pabis, and Page were selected to describe and compare the drying characteristics of mango slices. Comparisons were based on the coefficient of determination (R²), sum square error (SSE), root mean square error (RMSE) and reduced-chi square (χ²). Among the tested models, the Page model achieved the best fit. Moisture transfer from mango slices was described by applying the Fick’s diffusion model. Effective moisture diffusivity (Deff) values increased with increasing drying temperature and were found to range from 4.97 x 10^-10 m²/s to 10.83 x 10^-10 m²/s. The temperature dependence of the effective diffusivity was described by the Arrhenius-type relationship and the activation energy for the diffusion of the moisture associated with the mango slice was found to be 37.99 kJ/mol.