Cinética de secagem de folhas de Alibertia edulis (RICH.) A. Rich. Ex DC

Abstract

The objective of the present study was to evaluate the drying kinetics and diffusivity during the drying process of Alibertia edulis (RICH.) A. Rich. ex DC. leaves. The leaves were harvested with an initial moisture content of approximately 1.50 d.b. and subjected to drying under different controlled temperature conditions (40, 50, 60, and 70 °C) and an air-drying velocity of 0.4 m s⁻¹ in an experimental fixed-bed dryer, until reaching a moisture content of approximately 0.11 d.b. Eight mathematical models commonly used to describe the drying of agricultural products were fitted to the experimental data. Based on the results obtained, the Midilli model was the only one to satisfactorily fit and represent the drying kinetics of Alibertia edulis (RICH.) A. Rich. ex DC. leaves under all drying air conditions. Increasing the temperature resulted in shorter drying times and higher magnitudes of the effective diffusion coefficient. The activation energy was 57.44 kJ mol⁻¹ for the dried Alibertia edulis. leaves under an air-drying velocity of 0.4 m s⁻¹, within the temperature range of 40 to 70 °C.