MICROWAVE-DRYING CHARACTERISTICS OF BASIL

Abstract

The effect of microwave-drying technique on moisture content, moisture ratio, drying rate; drying time and effective moisture diffusivity of basil leaves (Ocimum Basillium L.) were investigated. By increasing the microwave output powers (180-900 W) and the sample amounts (25-100 g), the drying time decreased from 28 to 6.5 min and increased from 16 to 44 min, respectively. To determine the kinetic parameters, the drying data were fitted to various models based on the ratios of the differences between the initial and final moisture contents and equilibrium moisture content versus drying time. Among the models proposed, the semi-empirical logarithmic model gave a better fit for all drying conditions applied. The activation energy was calculated using an exponential expression based on Arrhenius equation. The relationship between the drying rate constant and effective moisture diffusivity was also estimated and gave a linear relationship.