Physical Properties of Guar Seeds

A study on the guar seeds (Cyamopsis tetragonoloba) was performed to investigate the effect of moisture content on the selected physical properties. Moisture contents of seeds were varied from 5.2% to 25.0%, dry basis (d.b.). Seed geometric parameters, such as average length, width, thickness, geometric-mean diameter, surface area, volume, increased but sphericity decreased with increase in moisture content. The 1,000-seed mass increased linearly with moisture content. Bulk density of guar seeds decreased linearly when moisture content was raised from 5.2% to 25.0% d.b. On the other hand, true density decreased till moisture content was increased up to 20%. Further increase in seed moisture resulted in increased true density, which has not been observed in other food grains. The porosity decreased till seed 15.3% moisture and then increased with further addition of moisture. Angle of repose, coefficients of static friction on three different surfaces (plywood, mild steel, and galvanized iron), and terminal velocity increased linearly with seed moisture content.