Plant Production

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https://hdl.handle.net/20.500.11888/3214

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Browsing Plant Production by Author "Nihad Said Qasid Ibrahem"

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    The effect of harvesting date on the oil chemical properties of Nabali baladi olive cultivar
    (2016) Nihad Said Qasid Ibrahem; Dr. Hassan Abo Qaoud
    Palestine is considered one of the original olive agricultural sites around the world. Harvesting date is one of the most important factors that contribute to oil quality. This study was conducted to investigate the effect of harvesting date of olives on oil chemical properties using Nabali Baladi (NB) cultivar. The study was conducted in a commercial olive orchards of NB planted in the Asira al Shamaliya village. Nine samples were taken starting from the September 20th 2014 of 10 days interval, each sample was tested for fruit characteristics including maturity index, moisture content ratio, fruit weight, length and width. The oil extracted by mechanical method was tested for acidity, peroxide, UV Light extinctions K, oil fatty acids composition, pigments, polyphenols and oxidative stability index. The oil content ratio was significantly increased during the harvesting dates, clear correlation was observed between the color index and each of the rate of fruit weight, oil content (85% and 98% correlation coefficient) respectively. Acidity, peroxide values were increased during harvesting dates. K232, K272, ΔK were within the limits of the International Oil Council specifications for extra virgin oil. Increasing of the linoleic acid ratio from 7.38% to 14,38% was observed, however, stearic ratio was decreased from 6.53% to 4,47%. Oleic and palmitic ratio was ranged between 71%, 14.7% respectively. Both chlorophyll and carotenoid were decreased from (27.4, 10.9) mg/kg to (14.1,6.3) mg/kg respectively. Total polyphenols have no significant differences during the harvest dates. The lowest value was observed in the last sampling date (129 mg/kg) and the highest value in the 1/11 date (445 mg/kg). The results obtained could be useful for determining the proper harvesting date .