Moisture Dependence of Some Physical and Morphological Properties of Chard (Beta vulgaris L. var. cicla) Seeds

摘要

Various physical properties of chard (Beta vulgaris L. var. cicla) seed were determined as a function of moisture content. The lengths of the major, medium and minor axes varied from 5.50 to 4.71, 4.88 to 4.03 and 4.28 to 3.53 mm, respectively, as themoisture content increased from 14.1 to 22.2% (dry basis). In the same moisture range, the arithmetic and geometric mean diameters increased from 4.09 to 4.89 and 4.06 to 4.86 mm, respectively. Studies on rewetted chard showed that the sphericity decreased from 1.152 to 1.135, whereas and projected area increased from 63.23 to 88.17 mm~2, respectively, with increase in moisture content from 14.1 to 22.2% (dry basis). The bulk density and true density decreased from 277.78 to 242.72 kg/m~3 and 740.74 to689.66 kg/m~3, whereas angle of repose increased from 23.96 to 26.57°, respectively. The static coefficients for friction of chard seeds were determined steel, plywood, wood, glass and galvanized sheet at various moisture contents. The static coefficient of friction increased on five structural surfaces namely, steel (0.300-0.422), galvanized sheet (0.393-0.530), plywood (0.499-0.712), wood (0.576-0.859) and glass (0.200-0.285) in the moisture range from 14.1 to 22.2% (dry basis).