Moisture dependent physical and mechanical properties of Mazafati date pit

Abstract

Knowing the physical and mechanical properties is very important for automating the activities associated with the date pit. The objective of this study was to determine physical and mechanical properties of date pit of Mazafati cultivar as a function of moisture content. The physical properties of the pits were determined in the moisture content range of 7% to 40% (wb). The date pits was compressed along the width at 0.08, 0.46, 0.55 and 0.64 (db) moisture contents to determine required force, deformation, and energy per volume (toughness) at rupture point. The results showed that the greatest length, width, thickness were 24.43, 9.21, 7.15 mm, respectively at moisture content of 40 % (wb). With increase moisture from 7% to 40% (wb) the true density of pits decreased from 1380 to 1209 kg.m^-3, the bulk density decreased from 729 to 655 kg.m^-3, the porosity decreased from 42.60 to 46.31%, the emptying angle of repose increased from 31.04 to 49.63 degree, and the filling angle of repose increased from 29.82 to 42.79 degree. The greatest friction coefficient of the date pits was obtained on plywood surface and the minimum value on iron surface at all moisture content levels. The greatest rupture force and toughness of the date pits were 1925.58 N and 5.34 mJ.mm^-3, respectively at moisture content of 0.08 (db). The greatest deformation at rupture point was 6.1 mm at moisture content of 0.46 (db).