Drying Kinetics of Nephelium Lappaceum (Rambutan) in a Drying Oven

Nephelium Lappaceum (Rambutan) is a local seasonal fruit that has a short storage life. In this study, the effects of temperature on the drying of Nephelium Lappaceum samples were investigated. The present investigation was conducted at drying temperatures of 40 degrees C, 50 degrees C, 60 degrees C, 70 degrees C and 80 degrees C for 24 hours, and the drying kinetics of Nephelium Lappaceum were evaluated. The experimental data were fitted to five thin layer mathematical models, including the Lewis, Page, Handerson and Pabis, logarithmic and two-term model. These models were evaluated by comparing the coefficient of determination (R-2), chi square (chi(2)), reduced sum square error (SSE) and root mean square error (RMSE). The logarithmic model best fit the experimental data. The effective diffusivity, D-eff, was calculated using Fick's diffusion equation, and the value of D-eff varied from 1.34 x 10(-10) to 4.36 x 10(-10) m(2)/s. The activation energy, E-a, and diffusivity constant, D-0, were 24.99 kJ/mol and 2.23 x 10(-6) m(2)/s, respectively. (C) 2015 The Authors. Published by Elsevier Ltd.