ABSTRACT
The jenipapo (Genipa americana L.) is a native species with medicinal importance and is widely used in Brazil. Due to the need for knowledge about the preprocessing of this species, this work was developed to evaluate the drying kinetics of the jenipapo leaves (G. americana L.), and also to determine the effective diffusivity of water during the process. The leaves were collected with an initial moisture content of 2.30 ± 0.05 (decimal db), and dried in three conditions of air temperature (35.3, 46.0 and 65.0°C) until they reach the equilibrium moisture content. The experimental data set were twelve mathematical models, recommended to represent the drying process of agricultural products. The magnitudes of the coefficient of determination (R2), the mean relative error (P), the average estimated error (SE) and the chi-square (X2), were used in order to verify the adequacy level of the models. The Henderson, modified Pabis and Midilli models presented appropriate adjustments to the experimental data, with the model Midilli, due to its simplicity, chosen to represent the drying kinetics of the jenipapo leaves. By increasing the temperature of the drying air from 35.3 to 46.0 and 65.0ºC, there was a reduction in the drying time of the jenipapo leaves, from 91.1 to 62.5 and to 24.2 hours, respectively. The effective diffusion coefficient increases with the temperature’s raise, and this relationship is described by the Arrhenius equation, which shows activation energy for liquid diffusion of 33.9 kJ mol-1.
Keywords
Model Midilli; dehydration; medicinal plants; activation; energy
