Propriedades mecânicas do feijão mungo (Vigna radiata (l.) r. wilczek) após a secagem e durante o armazenamento hermético

Abstract

Mung beans are a grain legume of Asian origin, the majority of cultivars of which have green seeds. It is cultivated mainly for human consumption, due to its considerable levels of vitamins, proteins and medicinal properties. In addition, production can also be used for animal feed and crop rotation. The handling of grains during harvest and post-harvest depends on the mechanical properties they present. These properties are used in sizing projects for machines and equipment used in processing. Thus, the objective of the present work was to evaluate the mechanical properties of mung beans after drying and throughout storage. The grains were harvested and threshed manually, with approximately 15% water content (b.u.). The drying process was carried out in an experimental fixed-bed convective dryer, in which the grains were subjected to drying at temperatures of 40 and 50 ºC with an air flow equal to 1.0 m s-1, until reaching the final water content of 11.5 ± 0.3% (b.u). After drying, the grains were stored in 200 mL Polyethylene Terephthalate bottles, covered with aluminum foil, to prevent the passage of light and subsequently placed in a laboratory environment. Analyzes were carried out every 60 days, for a period of 180 days. To evaluate the mechanical properties, fifteen repetitions of each treatment were performed, subsequently subjected to the uniaxial compression test. The rupture force, deformation, absorbed energy, tenacity modulus and hardness of the grains were determined. It was concluded that: drying temperatures of 40 and 50 °C and storage time of 180 days did not influence the variables of rupture force, deformation, absorbed energy, tenacity modulus and hardness of mung bean grains.