Physical Properties of Radish (Raphanus sativus L.) Seed as a Function of Moisture Content

The physical properties of radish (Raphanus sativus L.) seed were determined as a function of moisture content in the range of 6.95-19.08% dry basis (d.b.). The length L, width W and thickness T of seeds ranged from 3.34-3.53, 2.52-2.77 and 2.01-2.27 mm, respectively, as the moisture content increased from 6.95-19.08% d.b. In this moisture range, the 1000-seed mass increased from 11.9-13.85 g, the projected area from 4.76-5.86 mm(2), the sphericity from 0.77-0.80, the porosity from 30.17-33.07% and the terminal velocity from 7.16-7.93 m On the other hand, the bulk density decreased from 698.6-652.3 kg m(-3) and the true density from 1000.41-974.66 kg m(-3). Within the moisture content range, the static coefficient of friction of radish seed increased linearly against surfaces of four structural materials, namely, rubber (0.354-0.410), aluminum (0.295-0.346), stainless steel (0.245-0.306) and galvanized iron (0.308-0.368).