This study was aimed to study the dehydration kinetics of mango kernel with specific reference to sample thickness, drying temperature and mango varieties, and was performed prior to the preparation of flour from mango kernel. Kernels of four mango varieties (Boishakhi, Amrapali, Fazli and Ashwina) were separated manually and dried at 65˚C by slicing into 4, 6 and 8 mm thickness to know the thickness effect on drying kinetics. Again, 6 mm thick slices of kernels were dried at 55, 60 and 65˚C to know the temperature effect. Kinetics analysis resulted that the drying rate decreasing with the increase of thickness and decreasing of temperature. Ashwinas kernels having the highest initial moisture content (M0) had the highest drying rate constant (m), while the lowest m was noticed for Boishakhis kernels having the lowest M0. The values of the power-law index (n) of the drying model were 0.83, 0.32, 0.31 and 0.70 for kernels of Boishakhi, Amrapali, Fazli and Ashwina mango, respectively. The activation energy of water diffusion was in the range of 7.002-7.515 KCal/g-mole. Conclusively, this study revealed that moisture diffusivity and drying rate are greatly influenced by drying parameters and kernel varieties.
Key words: Mango kernel, Hot air drying, Rate constant, Activation energy
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