Effect of grain moisture content on the physical properties of some selected sorghum varieties

Determination of physical characteristics of grain of biomaterials is important in the design of harvesting, handling, and processing equipment. This helps in understanding the problem of separating grains from undesirable materials during threshing and winnowing, as well as in designing post-harvest handling equipments. Physical properties of sorghum grains from ten varieties (7 released and 3 breeding lines) were investigated under three different grain moisture content of 10%, 20% and 30% dry basis (d.b.). Results from the experiment revealed wide variation among the sorghum varieties on the physical properties measured. Arithmetic Mean Diameter ranged from 4.233 mm to 4.872 mm, while the Geometric Mean Diameter of the varieties ranged from 4.215 mm to 4.864 mm. Sphericity for the different sorghum varieties fall within the range of 0.86 to 0.96. It was also observed that the surface areas of the sorghum varieties are between 52.2 mm2 to 70.00 mm2. The results further showed that Aspect ratio ranged from 0.84 to 0.94 and the Angle of repose for the sorghum varieties were from 31.510 to 34.250. Result from the study revealed that, increase in moisture content led to increase in the surface area, arithmetic mean diameter, geometric mean diameter, sphericity and angle of repose. Variety and changes in moisture content significantly affected the physical properties determined.