Drying kinetics of cecropia pachystachya leaves

Abstract

The species Cecropia pachystachya has important medicinal purposes and its leaves have been used in pharmaceutical research, so the drying of this product may help maintaining its chemical properties and ensure safe storage. Thus, the objective of this study was to select mathematical models to represent the drying kinetics of Cecropia pachystachya leaves, determine the effective diffusion coefficient and obtain the activation energy during drying at different temperatures. Leaves were dried in an oven under five temperature conditions (40, 50, 60 and 70 °C), until reaching hygroscopic equilibrium moisture content. Among the models analyzed, the Logarithmic model best represented the drying kinetics at temperatures of 40 and 60 °C, whereas Modified Henderson & Pabis and Dryceleaves represented temperatures of 50 and 70 °C, respectively. The effective diffusion coefficient increased with increasing air temperature, and the activation energy for liquid diffusion in the drying process was 64.53 kJ mol-1.