Effects of Moisture Content on Physical and Mechanical Properties of Desma (Novella pentadesma) Seed

The effects of moisture content on physical and mechanical properties of desma seed were investigated in the moisture range of 9.2 to 17.8% (w.b.). The physical properties which include geometric mean diameter, bulk density and angle of repose were determined using standard known procedures and increased with increasing moisture content up to 17.8%. Their maximum values at 17.8 % moisture content were 12.88±1.65 mm, 667.47±10.2 kg/m3, and 35.97±0.24 degrees, respectively. The mechanical properties which include force and stress were determined using Instron machine (ZDM50-2313/56/18, Germany) and decreased with increase in moisture content up to 17.8% at peak, break and yield points of compression. The energy and deformation increased with increase in moisture content at all points of compression. The peak values of force, stress, energy and deformation at 17.8% moisture content were 98.62?3.46 N, 10.50?0.14 N/mm2, 0.24?0.06 Nm and 2.36?0.61 mm, respectively. The results are important in the design of desma seed oil expelling machine.