Department of Food Technology, Vocational School of Technical Sciences, Namik Kemal University, 59030 Tekirdağ, Turkey.
Department of Chemical and Physical Properties of Food, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland.
Molecules. 2019 Mar 21;24(6):1130. doi: 10.3390/molecules24061130.
The phenolic compound contents and antioxidant activities of the leaf extracts of nine olive genotypes were determined, and the obtained data were analysed using chemometric techniques. In the crude extracts, 12 compounds belonging to the secoiridoids, phenylethanoids, and flavonoids were identified. Oleuropein was the primary component for all genotypes, exhibiting a content of 21.0 to 98.0 mg/g extract. Hydroxytyrosol, verbascoside, luteolin 7--glucoside, and luteolin 4'--glucoside were also present in noticeable quantities. Genotypes differed to the greatest extent in the content of verbascoside (0.45⁻21.07 mg/g extract). The content of hydroxytyrosol ranged from 1.33 to 4.03 mg/g extract, and the aforementioned luteolin glucosides were present at 1.58⁻8.67 mg/g extract. The total phenolic content (TPC), DPPH and ABTS scavenging activities, ferric reducing antioxidant power (FRAP), and ability to inhibit the oxidation of -carotene-linoleic acid emulsion also varied significantly among genotypes. A hierarchical cluster analysis enabled the division of genotypes into three clusters with similarity above 60% in each group. GGE biplot analysis showed olive genotypes variability with respect to phenolic compound contents and antioxidant activities. Significant correlations among TPC, FRAP, the values of both radical scavenging assays, and the content of oleuropein were found. The contents of 7--glucoside and 4'--glucoside correlated with TPC, TEAC, FRAP, and the results of the emulsion oxidation assay.
测定了 9 个油橄榄基因型叶片提取物的酚类化合物含量和抗氧化活性，并采用化学计量学技术分析了所得数据。在粗提物中，鉴定出 12 种属于次级胆汁酸、苯乙醇和类黄酮的化合物。橄榄苦苷是所有基因型的主要成分，其含量为 21.0 至 98.0mg/g 提取物。羟基酪醇、毛蕊花糖苷、木樨草素 7--葡萄糖苷和木樨草素 4'--葡萄糖苷也以可观的量存在。基因型之间在毛蕊花糖苷含量上差异最大（0.45⁻21.07mg/g 提取物）。羟基酪醇的含量范围为 1.33 至 4.03mg/g 提取物，上述木樨草素葡萄糖苷的含量为 1.58⁻8.67mg/g 提取物。总酚含量（TPC）、DPPH 和 ABTS 清除活性、铁还原抗氧化能力（FRAP）以及抑制 -胡萝卜素-亚油酸乳液氧化的能力在基因型之间也有显著差异。层次聚类分析将基因型分为三组，每组的相似度均在 60%以上。GGE 双标图分析显示了油橄榄基因型在酚类化合物含量和抗氧化活性方面的变异性。TPC、FRAP、两种自由基清除测定值以及橄榄苦苷含量之间存在显著相关性。7--葡萄糖苷和 4'--葡萄糖苷的含量与 TPC、TEAC、FRAP 和乳液氧化测定结果相关。
