Some physical and mechanical properties of round red lentil grains

Abstract

The physical properties of round red lentil grains were determined as a function of moisture content in the range of 12.23% to 21.40% dry basis (d.b.). The average diameter and thickness were 4.28 and 2.59 mm, at a moisture content of 12.23% d.b., respectively. In the above moisture range, the arithmetic and geometric mean diameters increased from 3.7175 to 4.1473 mm and from 3.6179 to 4.0170 mm, respectively, while the sphericity decreased from 0.8458 to 0.8334. In the moisture range from 12.23% to 21.40% d.b., studies on rewetted round red lentil grains showed that the thousand grain mass increased from 40 to 50 g, the projected area from 24.46 to 37.80 mm(2), the true density from 800 to 950 kg m(-3), the porosity from 17.50% to 44.21%, and the terminal velocity from 6.00 to 7.60 m s(-1). The bulk density decreased from 660 to 530 kg m(-3) with an increase in the moisture content range of 12.23% to 21.40% d.b. The static coefficient of friction of round red lentil grains increased linearly against surfaces of six structural materials, namely, rubber (0.49-0.60), aluminum (0.47-0.55), stainless steel (0.37-0.44), galvanized iron (0.42-0.50), glass (0.34-0.40), and MDF (medium density fiberboard) (0.31-0.36) as the moisture content increased from 12.23% to 21.40% d.b.