Effect of moisture content on some physical and engineering properties of Grass pea (Lathyrus sativus L., Leguminous)

Abstract

In this study, physical and engineering properties such as length, diameter, size, mass of 1000 seeds, sphericity, surface area, volume, true density and bulk density of grass pea were determined. Determination of physical and engineering properties of grain and agricultural products is important in the design of harvesting, handling, and processing equipment. Physical and engineering properties of grass pea were performed over moisture content range from 10.65 to 19.92 (d.b.). Increasing of moisture content was found to increase mass of 1000 seeds kernel surface area, kernel volume, and static friction coefficient, while decreasing bulk density, true density, and porosity. Kernel length, width, thickness, and effective mean diameter increased from 6.342 to 6.43 mm, 5.48 to 5.87 mm, 5.16 to 5.21 mm, and 5.64 to 5.81 mm, respectively. Mass of 1000 seeds was found to increase from 115.27 to 123.75 gr. volume and sphericity were found to increase from 45.55 to 105 mm³ and 0.889 to 0.903, respectively. Bulk density, true density, and porosity were found to decrease with moisture content increase from 783.11 to 700.44 kg/m³, 2486.60 to 1180.62 kg/m³, and 46.65 to 45.59, respectively. Static friction coefficients were found to increase as moisture content increases. Static friction coefficient between grass pea seeds and plywood, glass and galvanized iron steel surface ranging from 0.274 to 0.502, 0.302 to 0.431 and 0.334 to 0.414, respectively. The largest increase in static friction coefficient with moisture content was observed for plywood surface.