PHYSICAL PROPERTIES OF SORGHUM (SORGHUM BICOLOR) GRAINS AS A FUNCTION OF MOISTURE CONTENT

Experiments were conducted to evaluate some moisture dependent physical properties of newly evolved variety of Sorghum ( Cv . Phule suchitra ) by MPKV Rahuri in the simulated moisture content range of 10.94 to 24.22 % (d. b.). The data on physical properties are essential to the design engineers for designing of various processing machineries. The sample of Phule suchitra was pr ocured from AICRP on sorghum. Cleaned and graded sample was used for experimentation. The sample was conditioned with predetermined quantity of distilled water and was placed in polythene bag in refrigerator for 8 days. It was observed that length, breadth and thickness were increased linearly with increase in moisture content. Grain size was increased from 4.09 to 4.53 mm with corresponding increase in moisture content from 10.94 to 24.22 % (d. b.). Similar trend was observed for AMD, SMD and EQD. Spheric ity was decreased from 81.79 to 79.63 % with increase in moisture content. Surface area, volume and thousand grain weight was linearly increased from 46.39 to 56.16 mm 2 , 29 to 38 mm 3 and 42.47 to 45.21 g respectively. It was observed that bulk density and true density decreased with increase in moisture content in the simulated range. Bulk density was decreased from 775.85 to 699.69 kg/m 3 . Whereas, true density was decreased from 1147.1 to 995.3 kg/m 3 . The porosity value does not show any specific trend, i t varied for every biological material. The values of angle of repose were increased from 26.75 to 29.31 with corresponding increase in moisture content. Values of Static coefficient of friction were found to be ranged between 0.58 to 0.66, 0.60 to 0.72 and 0.70 to 0.77 for glass, GI sheet and plywood surface, respectively. Minimum Static coefficient of fric tion was found for glass surface (0.58) whereas, maximum static coefficient of friction was found for plywood surface (0.70) at initial moisture content of 10.94 % (d. b.)