Determination of selected engineering properties of Moringa oleifera seed

Abstract

Engineering properties of agricultural products are very important in the design and manufacturing of processing machines. The methods adopted in the study were standard laboratory procedures for the determination of the engineering properties selected. In this research, the dimensional, gravimetric and frictional properties of Moringa oleifera seeds were determined as design parameters for the development of post-harvest equipment. The selected properties were: length, width, thickness, arithmetic and geometric diameters, surface areas, sphericity, moisture content, bulk and true densities, porosity, one thousand and unit seed weights, angle of repose and coefficient of static friction. The moisture contents used in the study were 7.82% and 15.82% dry basis (db). The mean seed length of 9.217±1.407 mm, width of 8.012±1.349 mm and thickness of 5.443±1.382 mm was found at moisture contents of 7.82% (db) respectively. While the mean seed length of 11.460±1.106 mm, width of 10.079±1.065 mm and thickness of 7.377±1.079 mm were obtained at moisture content of 15.82% (db) respectively. The mean arithmetic diameter, geometric mean diameter, sphericity and surface area at moisture content of 7.82% (db) were 7.557±1.3407 mm, 7.366±1.374 mm, 0.7964±0.048 mm, 176.185±64.416 mm2 respectively. Also, the mean arithmetic diameter, geometric mean diameter, sphericity and surface area at moisture content of 15.82% (db) were 9.639±1.049 mm, 9.475±1.065 mm, 0.826±0.030 mm, 285.476±65.753 mm2 respectively. The mean true density, bulk density, average porosity, unit mass and thousand seed mass at 7.82% (db) moisture content were found to be 0.5100±0.025 gcm-3, 0.247±0.0580 gcm3; 58.86%, 0.339±0.061 g, and 272.051±11.827 g respectively. Also, the average true density, bulk density, average porosity, unit mass and thousand seed mass at 15.82% (db) moisture content were 0.610±0.030 gcm-3, 0.253±0.005 gcm-3, 58.52%, 0.350±0.055 g, and 273.396±8.079 g respectively. The mean angle of repose, average static coefficient of friction on three different surfaces that include: glass, galvanized steel, and plywood at 7.82% (db) moisture content was found to be 17.834±0.350o, 0.437±0.003, 0.481±0.002, and 0.569±0.003 respectively. Also, the mean angle of repose, average static coefficient of friction on three different surfaces that include: glass, galvanized steel, and plywood at 15.82% (db) moisture content were found to be 19.345±0.409o, 0.471±0.002, 0.570±0.002, and 0.612±0.013 respectively. These parameters would serve as inputs for the efficient design of post-harvest equipment for M. oleifera seeds.