Effect of slice thickness and hot-air temperature on the kinetics of hot-air drying of Crabapple slices

Abstract

This study was investigated the effects of hot-air temperature and slice thickness on drying characteristics of Crabapple slices. Drying experiments were carried out in the ranges of 60-90 °C. The thickness conditions of Crabapple slices for thin layer drying were 3mm and 5mm. The increase in the temperature of the hot-air and the decrease in the thickness of the slicing causes the drying time to be significantly shortened. Fick’s diffusion model was applied to describe the water transfer of the Crabapple slices, and the effective diffusion coefficients varied from 0.6142 × 10^-8m²/s to 1.9867 × 10^-8m²/s in a given range of drying temperature. The effective diffusivity increases with increasing temperature. The activation energy values of Crabapple were 17.46 and 23.82 kJ/mol for the thickness of 3 and 5 mm, respectively. The Page model was revealed to be a better fit to describe the drying curve of Crabapple compared to other models.

Keywords:
crabapple slices; hot-air drying; drying kinetics; effective diffusion coefficients; activation energy