Papoti Vassiliki T, Tsimidou Maria Z
Department of Chemistry, Laboratory of Food Chemistry and Technology, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
J Agric Food Chem. 2009 May 13;57(9):3470-7. doi: 10.1021/jf900171d.
The impact of sampling parameters, that is, cultivar, leaf age, and sampling date, on the radical scavenging potential of olive leaf extracts was examined via the DPPH(*) and other assays. Total phenol content was estimated colorimetrically and by fluorometry, whereas phenol composition was assessed by RP-HPLC coupled with diode array, fluorometric, and MS detection systems. Oleuropein was not always the major leaf constituent. Considerable differences noted in individual phenol levels (hydroxytyrosol, oleuropein and other secoiridoids, verbascoside, and flavonoids) among samples were not reflected either in the total phenol content or in the radical scavenging potential of the extracts. It can be suggested that olive leaf is a robust source of radical scavengers throughout the year and that differentiation in the levels of individual components depends rather on sampling period than on cultivar or age. The latter does not present predictable regularity. Exploitation of all types of leaves expected in an olive tree shoot for the extraction of bioactive compounds is feasible.
通过DPPH（*）和其他分析方法，研究了采样参数（即品种、叶龄和采样日期）对橄榄叶提取物自由基清除能力的影响。总酚含量通过比色法和荧光法进行估算，而酚类成分则通过RP-HPLC结合二极管阵列、荧光和质谱检测系统进行评估。橄榄苦苷并不总是叶片的主要成分。样品中各酚类物质（羟基酪醇、橄榄苦苷和其他裂环环烯醚萜类、毛蕊花糖苷和黄酮类）含量存在显著差异，但这在提取物的总酚含量或自由基清除能力中均未体现。可以认为，橄榄叶全年都是自由基清除剂的丰富来源，各成分含量的差异更多地取决于采样时期，而非品种或叶龄。后者并不呈现可预测的规律。利用橄榄树枝条上预期的各类叶片来提取生物活性化合物是可行的。
