Halil Unal

Geometric and Mechanical Properties of Mung Bean (Vigna Radiata L.) Grain: Effect of Moisture

In this research, selected geometric and mechanical properties of mung bean grain were evaluated as a function of moisture content. Five levels of moisture content ranging from 7.28 to 17.77% d.b. (dry basis) were used. The average length, width, thickness, arithmetic and geometric mean diameters, sphericity, thousand grain mass and angle of repose ranged from 5.145 to 6.199 mm, 3.760 to 4.474 mm, 3.537 to 4.223 mm, 4.147 to 4.965 mm, 4.090 to 4.893 mm, 0.795 to 0.789, 52.3 to 64.6 g, and 25.87 to 29.38° as the moisture content increased from 7.28 to 17.77% d.b., respectively. The bulk density was found to be decreased from 821.3 to 745.2 kg/m3, whereas the grain volume, true density, porosity, terminal velocity, and projected area were found to be increased from 27.88 to 47.33 mm3, 1230.0 to 1456.7 kg/m3, 30.43 to 46.57%, 4.86 to 5.29 m/s, and 17.48 to 19.26 mm2, respectively. There is a 43% increase in surface area from grain moisture content of 7.28 to 17.77% d.b. The static coefficient of friction on various surfaces increased linearly with the increase in moisture content. The rubber as a surface for sliding offered the maximum friction followed by galvanised iron, medium density fibreboard, stainless steel, aluminium and glass sheet. As moisture content increased from 7.28 to 17.77%, the rupture forces values ranged from 67.39 to 39.44 N; 63.86 to 42.18 N, and 53.96 to 41.79 N for thickness (Z axis), length (Y-axis) and width (X-axis), respectively.

Some engineering properties of white kidney beans ( Phaseolus vulgaris L.)

Some engineering (physical and mechanical) properties of white kidney bean grains ( Phaseolus vulgaris L.) were determined as a function of moisture content in the range of 10.01 to 25.00% dry basis (d.b.). The average length, width and thickness were 8.638, 16.747 and 4.958 mm, at a moisture content of 10.01% d.b., respectively. Nonetheless, the thousand grain mass increased from 472.5 to 696.2 g, the projected area from 128.13 to 198.83 mm 2 , the true density from 1128.05 to 1290.85 kgm -3 , the porosity from 39.79 to 56.38% and the terminal velocity from 5.51 to 8.50 ms -1 in the moisture range from 10.01 to 25.01% d.b. The static coefficient of friction of white kidney bean grains increased linearly against surfaces of six structural materials, namely, rubber (0.501 to 0.727), stainless steel (0.384 to 0.468), aluminium (0.345 to 0.499), galvanized iron (0.346 to 0.489), medium density fibreboard (MDF) (0.325 to 0.426) and glass (0.287 to 0.345) as the moisture content increased from 10.01 to 25.00% d.b. The shelling resistance of white kidney bean grains decreased as the moisture content increased from 105.18 to 71.44 N. Key words: Engineering (physical and mechanical) properties, white kidney beans, moisture content, thousand grain mass, static coefficient of friction.

Comparison of some physical and chemical characteristics of buckwheat (Fagopyrum esculentum Moench) grains

ABSTRACT Several physical and chemical characteristics of two buckwheat varieties (commercial buckwheat and the Güneş variety) were determined and compared in terms of linear dimensions, length, width, thickness, arithmetic and geometric mean diameters, sphericity, surface area, aspect ratio, volume, weight of thousand grains, bulk and densities, porosity, terminal velocity, angle of repose, coefficient of static friction, rupture strength, apparent colour of buckwheat varieties, ash, protein, antioxidant capacity, total phenolic content and minerals (P, K, Mg, Na, Ca, Fe, Zn, Cu, B Cr and Pb) content. Multilinear models for two buckwheat varieties were developed and presented to predict the grain volume. All properties of the varieties that provide useful data to engineers in equipment design and post-harvest technology for the buckwheat grains were statistically different. These differences could be due to the individual characteristics of the varieties, environmental and growth conditions.