Physical properties of coriander seeds (Coriandrum sativum L.)

Physical properties of kernels, grains, and seeds are necessary for the design of equipment to handle, transport, process and store the crop. The physical properties of coriander seeds have been evaluated as a function of seed moisture content, varying from 7.10% to 18.94% (d.b.). In the moisture range, seed length decreased linearly from 4.74 to 4.61 mm, and width, thickness, arithmetic mean diameter, and geometric mean diameter increased linearly from 3.67 to 3.93 mm, 3.39 to 3.54 mm, 3.93 to 4.03 mm and 3.88 to 3.99 mm respectively with increase in moisture content. The sphericity, seed volume, and seed surface area increased nonlinearly from 0.820 to 0.867, 24.97 to 28.52 mm3, and 42.09 to 45.62 mm2, respectively. One thousand seed weight increased linearly from 8.72 to 9.71 g. The true density increased nonlinearly with moisture content from 332 to 349 kg/m3 while bulk density decreased linearly 234.1 to 220.2 kg/m3 in the range of moisture content between 7.10% and 18.94%, d.b. Also, porosity values of coriander seeds increased nonlinearly from 33.03% to 35.79%. The highest static coefficient of friction was found on the plywood surface. The static coefficient of friction increased nonlinearly from 0.435 to 0.877, 0.425 to 0.775, 0.379 to 0.839, 0.364 to 0.781, 0.344 to 0.650, and 0.325 to 0.694 for plywood, polypropylene knitted bag, polyvinyl chloride, galvanized iron, cast polypropylene and stainless steel surfaces, respectively. The angle of repose increased linearly from 24.9° to 30.7° with the increase of moisture content.