Stefanoudaki Evagelia, Williams Mark, Chartzoulakis Kostas, Harwood John
National Agricultural Research Foundation (NAGREF), Institute of Olive Trees and Subtropical Plants, 73100 Chania, Crete, Greece.
J Agric Food Chem. 2009 Aug 12;57(15):7048-55. doi: 10.1021/jf900862w.
Two irrigation treatments were applied to olive trees of the major commercial Cretan variety cv. Koroneiki, (a) irrigation with 0.4 evaporation class "A" pan and (b) rain-feed only, in two successive crop years to assess the effect of irrigation on olive oil quality. Olive fruits were harvested at their semiblack maturity stage. Data obtained indicated that irrigation increased fruit weight and oil content, but the standard quality indices (free fatty acids, peroxide value, K(232), and K(270)) of the oil were not affected significantly. However, irrigation affected some aspects of olive oil composition. There were changes in the proportions of polyunsaturated fatty acids (PUFAs), triacylglycerol molecular species, sterols, and aliphatic alcohols. Furthermore, the concentrations of the dialdehydic form of elenolic acid linked to 3,4-DHPEA (3,4-DHPEA-EDA) and the isomer of oleuropeine aglycon (3,4-DHPEA-EA) were higher in oils from non-irrigated trees. Tocopherol and total volatiles were higher in the oil produced from the non-irrigated trees. Such oil was graded more pungent when compared to oils produced from fruits of irrigated trees, although both oils were graded satisfactory by consumers.
在两个连续的作物年度中，对克里特岛主要商业品种科罗内基（cv. Koroneiki）的橄榄树进行了两种灌溉处理，（a）以0.4蒸发皿“A”级进行灌溉，（b）仅靠雨水灌溉，以评估灌溉对橄榄油品质的影响。橄榄果实在半黑成熟阶段采收。获得的数据表明，灌溉增加了果实重量和含油量，但油的标准品质指标（游离脂肪酸、过氧化值、K(232)和K(270)）未受到显著影响。然而，灌溉影响了橄榄油成分的某些方面。多不饱和脂肪酸（PUFAs）、三酰甘油分子种类、甾醇和脂肪醇的比例发生了变化。此外，与3,4-二羟基苯乙醇（3,4-DHPEA）相连的elenolic酸的二醛形式（3,4-DHPEA-EDA）和橄榄苦苷苷元的异构体（3,4-DHPEA-EA）在未灌溉树木的油中的浓度较高。生育酚和总挥发物在未灌溉树木生产的油中含量较高。与灌溉树木果实生产的油相比，这种油的辛辣味评级更高，尽管两种油在消费者评价中都被评为令人满意。
