Effect of moisture content on some physical properties of barley

Physical properties of barley (Hordeum vulgare L) seeds were determined as a function of moisture content. Several properties were studied in the moisture range from 13.15 to 45.82% dry basis, the length increased from 8.10 to 8.62 mm, the width from 3.42 to 3.74 mm, the thickness from 2.61 mm to 2.84 mm, the arithmetic and geometric diameter of seeds from 4.71 to 5.07 mm and from 4.16 to 4.50 mm, respectively. Besides, the 1000-seed mass increased from 39.46 to 51.13g. the surface area increased from 54.60 to 63.79 mm(2), the porosity increased from 42.69% to 44.44%, the angle of repose increased from 18.18 degrees to 27.31 degrees, and the static coefficient of friction showed an increase of 60.17%, 38.41% and 59.35% for the surfaces of plywood, galvanized steel and aluminum, respectively. From the experimental determinations it could be observed that only the apparent and true density decreased from 699.38 to 647.04 kg m(-3) and from 1220.30 to 1164.62 kg m(-3) respectively. In the range of evaluated moisture, all these properties except length - showed moisture dependence according to linear relationships; the length exhibited a behavior of second-order polynomial. Finally, the sphericity behaves differently presenting a maximum of 53.15% for a moisture content of 35.29%. (c) 2012 Elsevier B.V. All rights reserved.