Effect of moisture content on the physical properties of mung bean varieties grown in Abakaliki, Ebonyi State, Nigeria

Abstract

Some selected physical properties of five varieties of mung bean grain seeds (EBSUpant1, EBSUpant2, EBSUpant3, EBSUpant4, and EBSUpant5) grown by the Department of Crop and Landscape Management, Ebonyi State University, Abakaliki, such as geometric properties (linear dimensions, sphericity, geometric and arithmetic mean diameters and surface area), gravimetric properties (true density, bulk density and porosity) and frictional properties (angles of repose and coefficient of friction) were determined as a function of moisture content in the range of 8.59 to 21.48, 8.35 to 20.90, 8.48 to 21.20, 8.69 to 21.73, and 8.88 to 22.20 % (w.b.), respectively. The results showed that the mean values of all geometric properties increased with increasing moisture content. EBSUpant3 had the highest value of geometric properties among the mung bean varieties. The arithmetic and geometric diameters were lower than the length and higher than the width and thickness for the five varieties studied. Among the varieties, EBSUpant2 had the highest values of gravimetric properties, in all moisture contents studied. The maximum and minimum values of bulk density were obtained for EBSUpant2 (712.08 kg m^-3) and EBSUpant4 (650.05 kg m^-3). The angles of repose ranged from 25.72 to 29.88°, 25.64 to 29.70°, 25.68 to 29.79°, 25.75 to 29.96° and 25.81 to 30.12° for EBSUpant1, EBSUpant2, EBSUpant3, EBSUpant4, and EBSUpant5 respectively. At all moisture contents, the coefficient of static friction was the greatest against galvanized iron sheet (0.378-0.435), followed by plywood (0.362-0.403), and the least for stainless steel sheet (0.352-0.395). Among mung bean seed varieties, EBSUpant3 and EBSUpant5 showed the least and the greatest static coefficients of friction in all moisture contents studied, respectively.