Effect of moisture content on some physical properties of green wheat

Determination of physical characteristics of grain and agricultural commodities is important in the design of harvesting, handling, and processing equipment. Physical properties of green wheat (frikeh) kernels were established over moisture content range from 9.3 to 41.5% (w.b.) which covers the moisture range from harvesting to storage. Increasing of moisture content was found to increase axial dimensions, mass of 1000 seeds kernel surface area, kernel volume, and static friction coefficient, while decreasing bulk density, true density, and porosity. Kernel length, width, thickness, and effective mean diameter increased from 6.24 to 6.66 mm, 3.65 to 4.22 mm, 3.43 to 3.85 mm, and 4.19 to 4.75 mm, respectively. Mass of 1000 seeds was found to increase from 32.57 to 51.95 g. Kernel surface area, volume, and sphericity were found to increase from 47.07 to 61.02 mm(2), 28.84 to 41.95 mm(3), and 0.685 to 0.721, respectively. Bulk density, true density, and porosity were found to decrease with moisture content increase from 711.3 to 675.4 kg/m(3), 1333.2 to 1241 kg/m(3), and 46.65 to 45.59, respectively. Static friction coefficients were found to increase as moisture content increases. Static friction coefficient was largest between green wheat kernels and plywood surface ranging from 0.41 to 0.62, while the largest increase in static friction coefficient with moisture content was observed for stainless steel and ranged from 0.22 to 0.64. (c) 2006 Elsevier Ltd. All rights reserved.