PH—Postharvest Technology: Physical properties of chick pea seeds

Several physical properties of chick pea seeds were evaluated as functions of moisture content. The average length, width, thickness, the geometric mean diameter, unit mass and volume of seed were 9·342 mm, 7·722 mm, 7·752 mm, 8·358 mm, 0·324 g and 0·238 cm3, respectively, at a moisture content of 5·2% d.b. Studies on rewetted seed showed that as moisture content increased from 5·2 to 16·5% d.b., bulk and kernel density decreased from 800 to 741·4 kg m−3 and from 1428 to 1368 kg m−3, respectively. With increasing moisture content, porosity increased from 43·97 to 45·8%, projected area from 1·16 to 1·42 cm2, angle of repose from 24·5 to 27·9° and terminal velocity from 8·3 to 9·8 m s−1. The rupture strength decreased as the moisture content increased and the highest rupture strength occurred while loading along the Z- axis. The static and dynamic coefficients of friction of chick pea seed against galvanized sheet metal, plywood and rubber surfaces increased with moisture content in the range from 5·2 to 16·5% d.b. The highest coefficient of friction was against a rubber surface, ranging from 0·44 to 0·76.