Moisture dependent physical and mechanical properties of green laird lentil (Lens culinaris) grains

Abstract

This study was conducted to investigate some moisture dependent physical and mechanical properties of green laird lentil grains namely, grain dimensions, thousand grain mass, surface area, projected area, sphericity, bulk density, true density, porosity, terminal velocity, static coefficient of friction against different materials. The average diameter and thickness were 6.72 and 2.58 mm, at a moisture content of 11.36% d.b., respectively. In the above moisture range, the arithmetic and geometric mean diameters increased from 5.340 to 5.685 mm and from 4.879 to 5.260 mm, respectively, while the sphericity decreased from 0.727 to 0.744. In the moisture range from 11.36-25.08% d.b., studies on rewetted green laird lentil grains showed that the thousand grain mass increased from 72.00 to 73.90 g, the projected area from 36.98 to 55.60 mm2, the true density from 1170 to 1420 kg m-3, the porosity from 29.91 to 55.63% and the terminal velocity from 5.90 to 7.10 m s-1. The bulk density decreased from 820 to 630 kg m-3 with an increase in the moisture content range of 11.36-25.08% d.b. The static coefficient of friction of green laird lentil grains increased against surfaces of six structural materials, namely, rubber (0.51-0.58), aluminum (0.48-0.57), stainless steel (0.38-0.44), galvanized iron (0.42-0.50), glass (0.35-0.40) and MDF (medium density fiberboard) (0.31-0.36) as the moisture content increased from 11.36-25.08% d.b. © 2007 Asian Network For Scientific Information.