Cinética de secagem de grãos de feijão mungo (Vigna radiata l.) r. Wilczek

Abstract

Mung bean (Vigna radiata L.) is a grain legume, which in most of its cultivars characterize green color in its seeds. Its cultivation is mainly consumed as food, due to its considerable levels of vitamins, proteins and minerals. Therefore, for good productivity and formation of mung bean grains, it is necessary to maintain the quality formed during its development in the field and in all post-harvest stages. However, the post-harvest stages for this crop must be planned in order to ensure the final quality of the product driven by the drying process. In view of this, the importance of beans through the drying processes, the objective of the present work was to describe the behavior of the drying kinetics through adjustments of different mathematical models to the experimental drying data, in order to select which best model represents the phenomenon, in addition to determining the diffusion coefficient and activation energy at different temperatures. The mung bean grains were harvested with an initial moisture content of approximately 34% (w.b. wet basis) drying at temperatures of 40, 50, 60, 70 and 80 ºC in an experimental fixed layer dryer. Eleven mathematical models were adjusted to the experimental data on moisture ratio of bean grains, used to represent the drying of various agricultural products. Based on the data obtained, it is concluded that Thompson's model can be used to represent the drying kinetics of mung bean grains. The increase in air temperature resulted in a higher drying rate and an increase in the effective diffusion coefficient. The activation energy for net diffusion during the drying process of mung bean grains was 59,78 kJ mol-1. .