Mathematical Modeling Of Thin-Layer Drying Kinetics Of Cape Gooseberry (Physalis Peruviana L.)

Abstract

Drying kinetics of Cape gooseberry was studied and modeled during processing at four temperatures (60, 70, 80 and 90C). Desorption isotherm was obtained at 40C giving a monolayer moisture content of 0.086 g water/g d.m. Experimental drying curves showed that drying process took place only in the falling rate period. Several thin-layer drying models available in the literature were evaluated based on statistical tests as sum squared error (SSE), chi-square (c2) and determination coefficient (R2). Effective moisture diffusivity of Cape gooseberry was in the range of 4.67–14.9 ¥ 10-10 m2/s. A value of 38.78 kJ/mol was determined as activation energy. When comparing the experimental with predicted moisture values, the Midilli–Kucuk model was found to give the best fit quality (SSE < 0.001, c2 < 0.001, R2 > 0.99), showing this equation to predict very accurately the drying time of Cape gooseberry under the operating conditions studied.