Publicação on-line; 49 ref.; 5 tables; 2 illus.; Summary (En)

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.

Keywords: activation energy, embaúba, liquid diffusion, mathematical models, technology of forest products.