EVALUATION OF SOME PROPERTIES OF MORINGA OLEIFERA SEEDS

Abstract

A study of some moisture-dependent engineering properties of Moringa oleifera seed kernels was carried out in relation to post
harvest systems design. The investigation was done at four levels of moisture content:10.0, 17.0, 24.0 and 32.0% wet basis. The
properties studied include dynamic angle of repose, angle of internal friction, angle of surface friction, coefficient of static friction
at the four selected moisture content. The effect of moisture content on these properties of Moringa oleifera seed was investigated.
Other properties studied include bio-yield force (80.297N to 44.127), rupture force (110.037N to 60.658), deformation (2.337mm to
1.22N), energy for rupture (257.185J to 72.802J), compressive strength (5.8378N/mm2 to 3.1864N/mm2) and modulus of elasticity
(140.295N/mm2 to 94.191N/mm2). The angle of internal friction measured on plywood was 42.374° – 52.619°, mild steel 36.630° –
48.514°; angle of repose ranged from 17.643° – 23.500°, coefficient of friction as measured on plywood was from 0.570 – 0.749,
mild steel 0.480 – 0.674. Both linear and quadratic regression equations established had very high coefficients of determination (R2
> 0.9), which indicates that they described the relationships reasonably well. The coefficient of static friction of seed was higher on
plywood surface and lower on mild steel. This information will provide engineering information for designs of materials handling
and postharvest equipment design.