Effect of Microwave Power and Sample Thickness on Microwave Drying Kinetics Elephant Foot Yam (Amorphophallus Paeoniifolius)

Abstract

Elephant foot yam was dried under different microwave power ranging from 180 W to 900 W and sample thickness (5-15 mm) to study their effect on microwave drying kinetics. Drying time, drying rate, kinetic rate constant, effective moisture diffusivity and rehydration ratio are various factors studied. Increase in microwave power and decrease in sample thickness increased drying rate and decrease the drying time. The Fick’s diffusion method was also used to model the experimental data. The effective moisture diffusivity values were found to be in the drying conditions range of 4.44 x 10-9 m2/s to 1.17 x 10-7 m2/s. The modified Arrhenius type equation was used to calculate the activation and the resulting range was from 23.47 to 9.23 Wg-1 for varying thickness of the sample. On the other hand, the interaction effect of drying conditions on the average drying rate, drying time, drying rate constant and effective moisture diffusivity with high significance has been explained by the second order quadratic polynomial model.