Physical properties of Pearl Millet Grain

Abstract

Physical properties of grains are essential requirement for design of structures, machineries and equipment. Physical properties of pearl millet grain varieties ('Pusa composite 383', 'Pusa composite 701', 'Pusa composite 1201' and 'Pro agro 9444') were evaluated at varying moisture content (range: 10-30% db). The mean value of properties were recorded for length (2.997-3.172 mm), width (2.433-2.609 mm), thickness (2.036-2.209 mm), geometric mean diameter (2.453-2.629 mm), sphericity (0.821-0.833), projected area (5.745-6.509 mm2), thousand grain mass (9.114-10.123 g), grain volume (6.324-7.833 mm3), bulk density (711.9- 827.5 kg/m3), true density (1216.97-1314.17 kg/m3), porosity (37.02-41.47 %). Moreover, static friction coefficients against wood (0.220-0.397), mild steel (0.237-0.403), galvanised iron (0.231-0.408) and aluminium (0.245-0.423), emptying angle of repose (28.83-33.57 degree), filling angle of repose (24.34-29.38 degree) and rupture strength (22.36-49.47 N) were also determined. Mean values of properties like size, sphericity, projected area, thousand grain mass, grain volume, coefficient of friction at different surfaces and angle of repose increased with increase in grain moisture content; bulk density, true density and rupture strength decreased. Varietal differences were significant (p≤0.05) for some of the properties under investigation. Regression yielded high R2 values for linearly varying properties with moisture content except sphericity representing shape of the grain.