Some Physical Properties of Caper Seed

Some physical properties of caper seed were evaluated as a function of moisture content. In the moisture range from 6·03 to 16·35% d.b., the dimensions of the major, medium and minor axes varied from 3·09 to 3·67 mm, 2·40 to 2·90 mm and 1·52 to 1·87 mm, respectively. In the above moisture range, the arithmetic and geometric mean diameters increased from 2·34 to 2·81 mm and from 2·24 to 2·71 mm, respectively. The sphericity, surface area, projected area and thousand seed mass increased from 0·725 to 0·738, from 15·81 to 23·07 mm2, from 7·37 to 9·25 mm2, and from 6·60 to 7·75 g, respectively, while the bulk density, true density and porosity decreased from 438 to 399 kg m−3, 806 to 678 kg m−3 and 45·7 to 41·1%, respectively. The terminal velocity and angle of repose increased from 6·1 to 7·7 m s−1 and 21 to 32°, respectively, and the static coefficient of friction on four structural surfaces increased from 0·547 to 0·698 for rubber, 0·523 to 0·656 for plywood (with wood grains parallel to the direction of movement), 0·402 to 0·469 for galvanised metal sheet and 0·356 to 0·456 for aluminium sheet.