DRYING KINETICS OF UNRIPE PLANTAIN CHIPS USING CHARCOAL FUELLED CABINET DRYER.

Abstract

This study presents the thin layer drying behavior of unripe plantain slices (Musa paradisiaca) in a developed biomass cabinet dryer. The developed dryer provided an environment with an optimum operating temperature between 50 - 70⁰C meant for drying agricultural materials. The use of thin layer drying mechanisms and equations contribute to better understanding of drying food materials. The thin layer drying behaviour of agricultural products was identified based on the mathematical models which describe the heat and mass transfer phenomena of the products. In order to select a suitable drying model, fourteen different thin layer drying models were fitted to experimental data. Fick’s second law was used to calculate the moisture diffusivity with some simplifications. The results were compared for their goodness of fit in terms of correlation coefficient (R²), reduced chi square (χ2), root mean square error (RMSE), and mean bias error (MBE). Effective moisture diffusivity values of unripe plantain slices during drying were -56.8 x 10^-1, -2.60 x 10^-1 and -6.84 x 10^-1 m²/s for charcoal at 5, 10 and 15 mm thicknesses. Midilli and Kucuk, Modified Henderson and Wangh and Singh models were most suitable to describe the drying behavior of unripe plantain at 5, 10 and 15 mm thicknesses respectively when dried with charcoal and there were good agreements between the experimental and predicted variables