Convective drying kinetics of strawberry

Abstract

The drying kinetics of strawberry in a laboratory dryer was studied. The pre-treated with alkaline ethyl oleate solution and untreated strawberries were dried at selected temperatures of 50, 55 and 65 degrees C with a constant air velocity of 1.2 m/s. The drying rate curves showed that drying process took place only in the falling rate period. Thin-layer drying models of Lewis, Henderson and Pabis, logarithmic, Page, Wang and Singh evaluated based on coefficient of determination (R-2), reduced chi-square (chi(2)) and root means error (RMSE). The logarithmic model was found to be a better model for describing the characteristics of strawberry for both of the temperatures of 50 and 55 degrees C. The values obtained from Wang and Singh were found to be more reasonable for temperature of 65 degrees C than the other models. The transport of water during drying was described by Fick's equation and effective diffusivity varied from 4.95 x 10(-10) to 1.42 x 10(-9) m2/s. (c) 2007 Elsevier B.V. All rights reserved.