Physical properties of bambara groundnuts Original Research Article

The physical properties of bambara groundnut and other grains and seeds are necessary for the design of equipment to handle, transport, process and store the crop. The physical properties of bambara groundnut have been evaluated as a function of grain moisture content varying from 5% to 35% (wb). In this moisture range, grain length, width, thickness and geometric diameter increased from 10.5 to 14.65 mm, 9.48 to 11.65 mm, 8.50 to 10.90 mm and 9.65 to 12.55 mm respectively; the grain surface area and volume increased from 304 to 495 mm2 and from 425 to 900 mm3, respectively; the sphericity decreased from 0.90 to 0.87; the 1000-seed mass increased from 500.2 to 800.6 g; true and bulk densities decreased from 1.285 to 1.160 g/cm3 and from 0.795 to 0.696 g/cm3, respectively; the porosity and angle of repose increased with increase in moisture content up to 43.8% and 23.5°, respectively, at 20% moisture content; the sphericity decreased from 0.895 at 5% moisture content to 0.820 at 35% moisture content. The coefficient of static friction increased from 0.39 to 0.66, 0.29 to 0.58 and 0.25 to 0.49 for plywood, galvanised iron and aluminium, respectively.