Convective Drying of Apple: Mathematical Modeling and Determination of some Quality Parameters

In present study, the effects of drying air temperatures (50, 60 & 70°C) and velocities (0.6, 1.2 & 1.8 m s-1) on the drying kinetics of apple slices were investigated using a hot-air tray dryer. In addition, the effects of the drying variables on the quality characteristics (such as shrinkage & color) of dried apple were evaluated. In order to select the appropriate drying model, ten mathematical drying models were fitted to the experimental data. According to the statistical criteria (R2, SSE & RMSE) the Aghbashlo et al. (2009) model was found to be the best model to describe the drying behavior of apple slices. Multiple regression analysis was used to find the correlation of the new model coefficients with the temperature and air velocity. The ANOVA results indicated that the drying-air conditions had no significant effect on final shrinkage, Hunter color values and total color differences of dried apple. © 2010 Friends Science Publishers