Influence of drying conditions on the effective moisture diffusivity and energy of activation during the hot air drying of garlic

Abstract

Garlic (Allium sativum L.) is a vegetable spice that is a strong source of vitamin C and has antiseptic properties. The drying behavior of the garlic slices was investigated in a thin layer hot air drying at slice thicknesses of 2, 3 and 4 mm and air temperatures of 50, 60 and 70 degreesC. Fick's second law was used to calculate the moisture diffusivity coefficient, which varied from a minimum of 2.524 10-10 m2/s when the sample thickness was 2 mm and air temperature of 50 degreesC to a maximum value of 7.566 10-10 m2/s at the sample thickness of 4 mm and air temperature of 70 degreesC. The variation of effective diffusivity coefficient was depended on temperature by Arrhenius relationship. The energy of activation (Ea) for garlic slice varied from 30.424 to 36.365 kJ/mol.