Moisture-dependent Physical Properties of Detarium microcarpum Seeds

Abstract

Physical properties of Detarium microcarpum seed were investigated as a function of moisture content with a view to exploring the possibility of developing its bulk handling and processing equipment. In the moisture range of 8.2%-28.5% (d.b.), the major, intermediate and the minor axes increased from 2.95-3.21 cm, 1.85-2.61 cm, and 0.40-1.21 cm respectively. The arithmetic mean, geometric mean and equivalent sphere effective diameters determined at the same moisture level were significantly different from each other with the arithmetic mean diameter being of the highest value. The seed can be described as an irregularly shaped spherical disc. In the above moisture range, the surface area, one thousand seed weight, particle density and porosity increased linearly with moisture content from 354.62-433.19 cm 2 , 3.184-3.737kg, 1060-1316 kg/m 3 and 30% to 53.1% respectively, while bulk density decreased with increase in moisture content from 647.6-617.2 kg/m 3 . Angle of repose increased linearly with moisture content from 13.9 o -28.4 o . Static and kinetic coefficients of friction increased linearly with moisture content and varied with structural surface. Highest value of static coefficient of friction at each moisture level in the above range was on galvanized steel sheet, while the lowest value was on fiber glass. For the kinetic coefficient of friction, the highest values were on Hessian bag material, while the lowest values were on fiber glass.