The effect of pretreatments on air drying characteristics of persimmons

Abstract

In this study, whole and peeled persimmons were dried in the ranges of 55–75 °C of drying temperature in a hot air dryer. The effect of drying temperature and pretreatments on the drying characteristics was determined. Immersing in a solution of 20 % sucrose resulted in an increase in the drying rate of persimmons. A non-linear regression procedure was used to fit five thin-layer drying models available in the literature to the experimental moisture loss data. The Page and Modified Page models have shown a better fit to the experimental drying data as compared to other models. The effective diffusivity was determined to be 9.237 × 10−10–10.395 × 10−10 m2 s−1 for the blanched persimmons and 7.755 × 10−10–9.631 × 10−10 m2 s−1 for immersed sucrose solution persimmons. The activation energies for diffusion were calculated to be 56.09 kJ mol−1 (for blanched) and 10.28 kJ mol−1 (for immersed sucrose solution).