Physical Properties of Dates Fruits

Date palm (Phoenix dactylifera L.) is a monocotyledon of the family of the Palmae. The date palm is grown in Kutchh region of Gujarat. The physical properties of dates fruits (Variety: Zahidi) are necessary for the design of the equipment to handle, transport, process and storage. In this study some physical properties of dates fruits determined as a function of moisture content namely, dimensions, arithmetic and geometric mean diameter, sphericity, surface area, 1000 unit mass, bulk density, true density, porosity, angle of repose and coefficient of static friction. The average values of length, breadth and thickness of date palm fruit at different moisture content 69.5 and 61.56 % (w.b.) were found to be 33.65 and 33.12 mm, 22.12 and 22.03 mm, 20.02 and 19.95 mm respectively. The arithmetic and geometric mean diameter of fresh date fruit ranged from 24.29-26.59 mm and 23.51-25.96 mm respectively. The value of sphericity for different moisture content varied from 0.73 to 0.737. The bulk density varied from 491 to 477 kg/m3. The true density decreased from 576 to 533 kg/m3. The porosity varied from 10.56 to 14.75 % for the moisture content of 61.56 and 69.5% (w.b.). The angle of repose increased from 18.76 to 21.34o. It was found that the coefficient of static friction of date fruits varied from 0.31-0.35 (wood surface), 0.30-0.33 (steel surface) and 0.25-0.27 (glass surface).