Effect of rewetting on selected physical properties of 'Asontem' cowpea variety

Abstract

The physical properties relevant to the design and manufacture of handling, storage and processing equipment were determined under varying grain moisture content for 'Asontem' cowpea variety between 8.07%wb and 22.54%wb. The length, width, thickness, geometric mean diameter, surface area, volume, 1000 grain mass, bulk density, true density, filling angle of repose and the static coefficient of friction increased with increasing moisture content during rewetting. In the moisture content range of 8.07% w.b. to 22.54% w.b., the length, width and thickness increased non-linearly from 7.00 to 7.29mm, 6.27 to 6.33mm and 4.54 to 4.69mm, respectively. The geometric mean diameter, surface area, volume and 1000 grain mass increased from 5.83 to 5.99mm, 107.03 to 113.09mm 2, 104.45 to 113.45mm 3 and 120.15 to 130.58g, respectively while bulk density and true density decreased non-linearly from 752.95 to 682.93kg/m 3 and 1219.90 to 1161.39 kg/m 3, respectively. The filling angle of repose increased non-linearly from 27.81 to 32.31 while the coefficient of static friction also increased non-linearly from 0.29 to 0.41, 0.31 to 0.45 and 0.25 to 0.32 for plywood, mild steel and rubber respectively. Mild steel offered the highest coefficient of friction followed closely by plywood then rubber. © 2006-2012 Asian Research Publishing Network (ARPN).