Thin Layer Modeling of the Convective Drying of Barberry Fruit (<em>Berberis vulgaris</em>)

Abstract

In this study, the drying kinetics of seedless barberry fruit was studied at 55, 65 and 75˚C air temperatures and 1±0.2 m/s air velocity in a laboratory thin layer dryer with forced convection. Samples were subjected to two different pretreatments (citric acid and vapor). The drying of seedless barberry fruit took place in the falling rate drying period. Ten thin layer-drying models were fitted to the experimental moisture ratio. Compared with other models the Midilli <em>et al</em>. (2002) drying model was found to satisfactorily describe the drying curves of barberry with highest amounts of coefficient of determination (r²) and lowest amounts of reduced chi-square(x²), Mean Bias Error (MBE) and Root Mean Square Error (RMSE). The effective moisture diffusivity (D_eff) of barberry increased as the drying air temperature increased. An Arrhenius relation with activation energy values of 45.577 kJ/mol (citric acid pretreatment) expressed the effect of temperature on the diffusivity.