Effects of moisture content, seed size, loading rate and seed orientation on force and energy required for fracturing cumin seed ( Cuminum cyminum Linn.) under quasi-static loading

Force and deformation curve of agricultural material must be provided for proper design of harvesting, processing machineries. In this research, fracture resistance of whole cumin seed was measured in terms of average compressive force, seed rupture force and energy absorbed. In this study 10 treatments were performed as randomized complete block design with 20 replications. Cumin seeds were quasi-statically loaded in horizontal and vertical orientations with moisture contents in three levels: 5.7%, 9.5%, and 15% seed size in three levels: small, medium, and large; loading rates in two levels: 2 and 5 mm/min; and two seed orientations: horizontal and vertical. The results showed that the force required for initiating seed rupture decreased from 15.7 to 11.96 N and 58.2 to 28.8 N, and the energy absorbed at seed rupture increased from 1.8 to 8.6 mJ and 7.6 to 14.6 mJ, with increase in moisture content from 5.7% to 15% d.b., for vertical and horizontal orientations, respectively. This showed that seeds are more flexible in horizontal orientation. Rupture force requires less energy under vertical loading than horizontal loading. Maximum energy absorbed was found to be 15.3 mJ for small seed with 15% moisture content under horizontal loading. Minimum energy observed was 1.73 mJ for large seed with 5.7% moisture content under vertical loading. The highest mechanical strength (60 N) is related to a small seed with a moisture content of 5.7% under horizontal loading and the lowest (10.8 N) is attributable to a large seed with a moisture content of 15% under vertical loading. Energy absorbed by the small seed at high moisture content increased in horizontal orientations of loading.