Oil quality and quantity of three olive cultivars as influenced by harvesting date in the middle and southern parts of Jordan
2009
Al-Maaitah, M.I. (Mu'tah Univ., Al-Karak (Jordan). Plant Production Dept.) | Al-Absi, K.M. (Mu'tah Univ., Al-Karak (Jordan). Plant Production Dept.) | Al-Rawashdeh, A. (Mu'tah Univ., Al-Karak (Jordan). Nutrition and Food Technology Dept.)
Olive fruits of three promising Jordan cultivars (Nabali, Improved Nabali and Abo-shoka) were harvested at different harvesting dates at two locations in order to investigate the influence of cultivar and harvesting date on oil quality. The olive fruits were harvested manually at 15 day intervals throughout the experiment period, starting in October 15, 2006. The results showed that with later harvesting there was an increase in oil content, acidity, peroxide value and average fruit weight, while there was a decrease in fruit moisture and chlorophyll content at both locations. Refractive index (at 25 degree C) remains almost constant. The olive cultivars did not respond similarly. At the Al-Mshaqar orchard, cv. Improved Nabali had the highest peroxide value and moisture percentage, while cv. Abo-shoka had the highest chlorophyll content and average fruit weight. The highest oil percentage (fresh weight basis) was obtained for Nabali. However, at Wadi-bin Hamad orchard, cv. Improved Nabali had the highest acidity. Abo-shoka had the highest chlorophyll content, moisture percentage and average fruit weight. The highest oil accumulation was for Nabali. The result proved that olive cultivar and harvesting date combine together to influence oil quality and quantity. In the light of the results, it is concluded that the optimum harvesting date to obtain the best olive oil quality and quantity is dependent on location, cultivar and harvesting date. It could be recommended that the harvest be delayed to obtain both best quality and quantity. The current results indicate that the acidity and peroxide value of the three cultivars did not exceed the maximum limit for extra virgin olive oil.
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