Assessment of Engineering Properties of Proso Millet (Panicum miliaceum)

Abstract

Engineering properties of grain and kernel are required to design crop production, material handling and processing equipment. A study was conducted to determine the properties of grain and kernel of Panicum miliaceum at different moisture contents in range of 6.5−26.5 % (d.b.). The length, width, thickness and geometric mean diameter of Panicum miliaceum were observed in the range of 2.22−2.36 mm, 2.08−2.24 mm, 1.93−2.21 mm, 2.07−2.27 mm for grain and 1.87−1.98 mm, 1.73−1.97 mm, 1.63−1.80 mm, 1.74−1.91 mm for kernel, respectively. Sphericity ranged between 0.93−0.97 for the grain, and 0.93−0.96 for the kernel. Surface area, volume and thousand-grain weight increased from 12.73 mm2 to 15.64 mm2, 4.25 mm2 to 5.80 mm3, 5.25 g to 6.70 g for grain; and 8.94 mm3 to 11.14 mm2, 2.50 mm3 to 3.50 mm3, 3.21 g to 4.15 g for kernel, respectively. True density of grain and kernel increased with increase in moisture content. Bulk density decreased from 765.5 kg.m-3 to 697.57 kg.m-3. Similarly, in case of kernel, bulk density decreased from 845.33 kg.m-3 to 724.97 kg.m-3. Terminal velocity of grain and kernel ranged from 1.68 m.s-1 to 2.77 m.s-1 and 0.80 m.s-1 to 1.89 m.s-1, respectively and increasing trend was observed with moisture content. The coefficient of internal friction of grain and kernel increased with increase in moisture content from 0.48 to 0.68 and 0.69 to 0.90, respectively. The geometric, gravimetric, aerodynamic and frictional properties of grain and kernel of Panicum miliaceum at different moisture contents were found to be different at 5 % significance level.