Drying time, moisture diffusivity (De), mass transfer coefficient (hm), Biot number (Bim), activation energy (Eac and Ead), mass shrinkage ratio (Msr) and pH were determined during drying of melon slices at four different air drying temperatures of 40, 50, 60 and 70 ºC, and three slice thicknesses of 2, 4, 6 mm for a constant air velocity of 0.5 m s-1. De, hm, and Bim increased with decrease in moisture content and increase in temperature and slice thickness. Correlations for mass transfer parameters including moisture content, air temperature and slice thickness of the melon slice drying were developed. The value of Msr increased with increase in slice thickness and decrease in air temperature. The activation energy for convective mass transfer (Eac) is higher than that for mass diffusion (Ead). The average values of mass transfer parameters varied from 1.81 to 34.26×10-11 m2 s-1 for De , 1.07 to 10.68×10-9 m s-1 for hm , 0.101 to 0.196 for Bim, 34.61 to 41.06 kJ mol-1 for Ead and 45.24 to 51.30 kJ mol-1 for Eac over the temperature, air velocity and slice thicknesses range.
