determination of some physical properties of native lentil seeds of zabol as a function of moisture content

Taking into account the necessity of determination of physical properties to design of storage, handling, and processing systems for agricultural products, the object of this study was intended to determine some physical characteristics of native lentil seed of zabol such as axial dimensions, surface area, geometric mean diameter, sphericity, filling angle of repose, bulk and true densities, true volume, porosity as well as coefficient of static friction against various  surfaces. analysis of data showed that all physical properties of the lentil seeds were significantly affected with the moisture content in the studied range (4.7% to 19.8% w.b.). the axial dimensions of lentil seeds namely length, width, thickness and also one thousand seed mass of lentil seeds respectively increased from 3.88 to 4.56 mm, 3.69 to 4.21 mm, 2.05 to2.29 mm and 12.14 to 22-73 as the moisture content increased. the values of surface area (11.29-15.12 mm2) and geometric mean diameter (3.08 - 3.49 mm) of lentil seeds increased with increasing moisture content while the sphericity (79.61 to 76.69%) decreased. the filling angle of repose of the seeds increased significantly with an increase in moisture content. so, it changed from 26.57 at moisture content 4.7 to 29.74 at moisture content 19.8 (w.b. %). the values of bulk and true densities of lentil seeds decreased respectively from 546 to 476 kg/m3 and 1390 to 1270 kg/m3 as the moisture content increased. the true volume (6.15 – 6.71 mm3) and porosity (60.71 to 62.68 %) of lentil seeds increased linearly with increasing moisture content. the values of the coefficient of static friction increased as the moisture content of lentil seeds increased and also the values of this parameter with respect to galvanized iron (0.61-0.64) and fiberglass (0.60-0.64) were greater than that on the glass surface (0.53-0.62).