Physical properties of calabash nutmeg (Monodora myristica) seeds Original Research Article

Physical properties often required for the designing of cleaning, dehulling and sundry grain processing machineries were determined for calabash nutmeg seeds, at moisture content of 7.67% (wet basis). The average of each of the three principal diameters and seed mass were 18.1, 13.7, 12.4 mm and 1.18 g respectively. Mean values for sphericity and roundness were 67.97% and 64.27%. True density, bulk density and porosity were 833.2, 429.4 kg m3 and 48.4% respectively. The coefficient of static friction was 0.47 parallel to the plywood grain, 0.73 perpendicular to the plywood grain, 0.52 on galvanized steel, 0.58 on mild steel and 0.47 on Formica®. Dynamic angle of repose on the four structural materials ranged from 28.10° to 32.22°. The suspension air velocity for the whole seed, kernel (cotyledon only), split halves of cotyledon, and hull were 13.8, 4.92, 4.43 and 3.15 m s−1 respectively. The specific heat capacity of the seed at 80 °C was 1.85 kJ kg−1 K−1.