Central Institute of Agricultural Engineering, Nabi Bagh, Bhopal-462038
The physical properties of the cumin seeds were evaluated as a function of moisture content. The average length, width and thickness of cumin seeds were 4.75, 1.37 and 1.28 mm respectively at 7.78% (db) moisture content. The geometric mean diameter, density and terminal velocity were observed as 2.067 mm, 0.466 g/cm3 and 2.45 m/s. The static coefficient of friction varied from material to material and depends on the roughness of the seeds. The highest coefficient of static friction was found over mild steel and lowest over sunmica sheet. The angle of repose and seed rupture force were found to be 34° and 43.67 N in the moisture range from 7.78 to 20.65% (db). Studies on rewetted cumin seeds showed that length, width, thickness, diameter of equivalent sphere, mass of 1000 seeds and porosity increased linearly with the increase in moisture content. The angle of repose increased from 33 to 46 degrees and porosity from 50.96 to 55.31%. The bulk density initially increased from 484.55 to 492.82 kg/m3 then decreased to 432.08 kg/m3. Ttrue density increased linearly from 1054 to 1130 kg/m3 in the moisture range of 7.78 to 20.65% (db).
