Thin layer drying characteristics and modeling of melon slices (Cucumismelo).

The thin-layer drying characteristics of melon slices were investigated under four air temperatures, 40, 50, 60 and 70 °C, two different thicknesses of 4 and 6 mm, and natural convective airflow of 0.01 m/s. Data were analyzed to obtain diffusivity values from the period of falling drying rate. Four mathematical models for describing the thin-layer drying behavior of melon were investigated. The results show that the Midilli et al. is the most appropriate model for drying behaviour of thin layer melon slices. An analysis of variance (ANOVA) revealed that temperature and slice thickness significantly affected the drying time, drying rate, effective diffusivity, and activation energy. The effective diffusivity varied from 1.21×10 −8 m 2 /s to 4.18×10 −8 m 2 /s for slice thickness of 4mm, and from 1.69×10 −8 to 8.54×10 −8 m 2 /s for slice thickness of 6 mm. The activation energy for the moisture diffusion was determined to be 36.40 and 49.47 kJ/mol for the slice thicknesses of 4 and 6mm, respectively.