沙田柚不同组织部位酚类物质组成及其抗氧化活性研究

Phenolic compositions and antioxidant activity of different tissue parts of Shatianyou (Citrus grandis L. Osbeck)

中文关键词:  沙田柚  游离酚  结合酚  抗氧化活性

英文关键词:Citrus grandis L. Osbeck  free phenolics  bound phenolics  antioxidant activity

中文摘要:

      目的 揭示沙田柚不同部位酚类物质组成和抗氧化活性的差异。方法 提取沙田柚油胞层、白皮层、囊衣和籽中游离酚和结合酚, 测定其总酚、总黄酮含量, 单体酚组成和抗氧化活性, 并采用皮尔森相关性分析确定酚类物质含量与抗氧化活性之间的相关性。结果 沙田柚各部位酚类物质主要以游离酚为主, 其总酚、总黄酮含量变幅分别为2.01~13.28 mg GAE/g DW和3.79~15.2 mg RE/g DW, 油胞层和白皮层总酚、总黄酮含量均高于囊衣和籽。从沙田柚各部位鉴定出柚皮苷、橙皮素、甜橙黄酮、对羟基苯甲酸、对香豆酸和阿魏酸共6个单体酚, 柚皮苷是各部位中最主要的黄酮类化合物且以白皮层中含量最高。沙田柚各部位铁离子还原能力(ferricreducing antioxidant power, FRAP)和氧自由基吸收能力(oxygen radical absorbance capacity, ORAC)变幅分别为7.36~69.26 mmol TE/g DW和116.91~625.1 μmol TE/g DW, 甜橙黄酮是各部位发挥FRAP活性的重要成分, 而柚皮苷是各部位发挥ORAC活性的重要成分。结论 沙田柚副产物, 尤其是果皮(油胞层和白皮层), 是天然酚类物质的来源。

英文摘要:

      Objective To reveal the differences of phenolic compositions and antioxidant activity in different parts of Shatianyou (Citrus grandis L. Osbeck). Methods Free and bound phenolics of flavedo, albedo, septum and seed of Shatianyou were extracted. The total phenolic and flavonoid content, the phenolic composition, together with the antioxidant activity of both free and bound phenolic extracts were determined. Pearson correlation tests were conducted to determine the correlation between phenolic contents and antioxidant activity. Results Phenolics and flavonoids existed mainly in free form in different parts of Shatianyou, of which the total phenolic and flavonoid content were 2.01-13.28 mg GAE/g DW and 3.79-15.2 mg RE/g DW, respectively. Flavedo and albedo showed higher phenolic and flavonoid content than those of septum and seed. Six individual phenolics, including naringin, hesperetin, sinensetin, p-hydroxybenzonic, p-coumaric acid and ferulic acid, were detected in different parts of Shatianyou. Naringin was the most abundant flavonoid compound in each part, and its content was highest in albedo. The ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) in different parts of Shatianyou were 7.36-69.26 mmol TE/g DW and 116.91-625.1 μmol TE/g DW, respectively. Sinensetin was an important component for each part to exert FRAP activity, while naringin was an important component for each part to exert ORAC activity. Conclusion By-products of Shatianyou, especially pummelo peel (flavedo and albedo), are natural source of phenolics.