INVESTIGATION AND DETERMINATION OF OPTIMUM CONDITIONS OF DATES FRUIT FOR DESTONING WITH NEEDLE-CUP MECHANISM (C.V. ESTAMER

This study was carried out to find the optimum Estameran date fruit preparation conditions for depitting with needle cup depitting machine in a full factorial experiment with 4 factors of fruit diameter at 4 levels (16-18 mm, 18-20 mm, 20-22 mm and 22-24 mm), moisture content at 3 levels (14-16, 16-18 and 18-20%), fruit surface treatment at 3 levels (edible oil, rice flour, and control) and fruit orientation at two levels (upright and upsidedown) in a completely randomized design with 4 replications. Based on the results moisture content and surface treatment which both are of fruit conditioning charachers, are the main factors affecting the fruit recovery and by controlling moisture content at low levels and using proper treatment material, high levels of fruit recovery could be achived. maximum mean fruit recovery, 99.22%, were attained at moisture content of 14-16% and treating fruit surface with rice flour. The edible oil at the same condition resulted in 96.30% of fruit recovery. Results showed that the total average amount of fruit whole and break pits in depitted dates in 14-16% moisture content, placed downward in depitting cups and treated with edible oil for diameter ranges of 16-18mm, 18-20mm, and 20-22mm were zero and 6.65% for diameter range of 22-24mm. these criterion for rice flour for 16-18mm and 18-20mm of fruit diameter were zero and 1.25% and 2.5% for 20-22mm and 22-24mm of fruit diameter ranges respectively. In general it could be concluded that machine depitting of Estameran date at least for 3 diametre ranges of 16-18mm, 18-20mm, and 20-22mm is possible with proper preparation of the fruit. upside down placemet of oil-trated Estameran fruits is the most proper condition for depitting operation based on the results and ease of implementation. This ooperation must be combined with fruit grade and moisture content control to gain the desired results.