Effect of Moisture Content on Physical Properties of Barley Seeds

In this article, the size, dimensions, volume, bulk and particle densities, empyting and filling angles of repose and friction coefficients against different surfaces were evaluated for two varieties of barley, Sahra and Valfajr, as a function of moisture content in the range of ۱۰.۱۲ to ۴۲.۱۷ (w.b.%). Most physical properties of barley varieties were significantly affected by moisture content variation. The length, width, thickness and unit mass of Sahra variety increased from ۹.۸۸ to ۱۰.۱۶ mm, ۳.۳۷ to ۳.۸۹ mm, ۲.۵۴ to ۲.۸۰ mm and ۰.۰۴۸ to ۰.۰۷۴ g, respectively, as the moisture content increased. The respective values for Valfajr varied from ۸.۳۷ to ۸.۸۷ mm, ۳.۰۳ to ۳.۲۱ mm, ۲.۲۱ to ۲.۳۷ mm and ۰.۰۳۷ to ۰.۰۴۳ g, respectively. In Sahra variety, sphericity, geometric mean diameter, bulk density, particle density and porosity increased from ۴۴.۵۹ to ۴۷.۴۰%; ۴.۳۸ to ۴.۷۹ mm; ۵۶۸.۱۰ to ۶۱۳.۶۸ kg m-۳; ۱,۰۹۹.۶۵ to ۱,۲۴۵.۷۲ kg m-۳ and ۴۸.۳۴ to ۵۰.۷۴%, respectively. The coefficient of static friction increased linearly against all the tested surfaces as the moisture content increased. In Valfajr variety, sphericity increased from ۴۵.۷۹ to ۴۵.۸۹%; geometric mean diameter increased from ۳.۸۲ to ۴.۰۶ mm; bulk density increased from ۵۷۹.۶۸ to ۶۰۸.۵۸ kg m-۳; particle density varied from ۱,۴۱۰.۸۲ to ۱,۲۳۰.۶۱ kg m-۳; porosity varied from ۵۸.۹۱ to ۵۰.۵۵% and the coefficient of static friction increased linearly against all the tested surfaces as the moisture content increased. The angle of repose for emptying and filling increased linearly as well.