Studies on influence of moisture content on engineering properties of kodo and kutki millets

Abstract

Minor millets like kodo and kutki millet were studied for their engineering properties at different moisture contents (10–20%, db, dry basis). The results showed thatthe geometric properties of grain viz., length (2.26 mm-2.69 mm), breadth (1.39 mm-2.15 mm), thickness (1.24 mm-2.07 mm), arithmetic mean diameter (1.66 mm-2.30 mm), geometric mean diameter (1.59 mm-2.28 mm), square mean diameter (2.82 mm-3.97 mm), equivalent diameter (2.02 mm-2.85 mm), sphericity (0.67–0.86), aspect ratio (0.59–0.86) and surface area (8.96 mm2-16.85 mm2) increased linearly with increase in moisture content. The gravimetric properties of grain viz., unit volume (3.91 mm3-12.9 mm3), thousand kernel weight (1.87 g-4.36 g) increased; bulk density (520 kg m3-709 kg m3), true density (1056 kg m3-1852 kg m3) and porosity (34.6%-64.1%) decreased with increase in moisture content. The angle of repose (27.1°-32.8°) showed an increasing trend. Coefficient of static friction of these minor millets against different contact surfaces showed an increasing trend with moisture content. The grain hardness showed a decreasing trend with increasing moisture content