Mathematical modeling of thin layer microwave drying kinetics of elephant foot yam (Amorphophallus paeoniifolius)

The effect of microwave power ranging from 180 W to 900 W was studied on elephant foot yam. The various factors of the sample that were investigated were drying time, drying rate, kinetic rate constant, effective moisture diffusivity. It was observed that the drying rate was increasing with increase in microwave power and drying time decrease with increase in microwave power. Various thin layer drying models were considered for the evaluation of parameters of drying kinetics, out of which semi empirical Midilli et al. model presented the best fit for all conditions of drying, giving a high value of R2 ( 0.998) and low value of RSS, RMSE and Chi square. The Fick’s diffusion method was also used to estimate the effective moisture diffusivity and values were found to be in range of 4.44 x 10^-9 m²/s to 4.2 x 10^-8 m²/s at the drying conditions. The modified Arrhenius type equation was used to calculate the activation and the resulting range was from 24.7 Wg^-1 for varying thickness of the sample.