不同成熟期灵武长枣酚类组分及抗氧化活性差异分析

Changes in Phenolic Components and Antioxidant Activity of Jujube Fruits(Zizyphus jujuba Mill. cv. Lingwuchangzao) during Different Growth Stages

对不同成熟期(白绿、微红、大半红、全红)灵武长枣酚类成分组成、含量及其活性的差异进行研究,以期发现不同成熟期灵武长枣抗氧化功能品质的变化规律。以宁夏不同成熟期的灵武长枣为研究材料,比较总酚、总黄酮及酚类物质的组成及抗氧化能力(DPPH自由基清除率、抗亚油酸过氧化能力和总还原力)的差异性。结果表明:1)4个成熟期的灵武长枣总酚含量变化范围为2 996.60~5 801.84μg/g(以没食子酸计),总黄酮含量变化范围为33.12~122.12μg/g(以芦丁计),白绿期总酚和总黄酮含量最高,两者随着果实的成熟逐渐下降。2)灵武长枣中检出的酚类物质主要有根皮苷、阿魏酸、肉桂酸、柚皮素和根皮素,各含量均呈现先上升后下降趋势,微红期含量最高。3)灵武长枣抗氧化活性表现为白绿>微红>大半红>全红。抗氧化能力与总黄酮、总酚含量呈显著相关性(P<0.05),与检测出的5种酚类物质相关性较弱(P>0.05),决定其抗氧化能力的酚类物质仍有待进一步确定。白绿期灵武长枣的抗氧化活性均比其他成熟期高,因此从该时期获取天然抗氧化活性物质更为合适。

Phenolic components in Lingwuchangzao jujubes(Zizyphus jujuba Mill. cv. Lingwuchangzao) during four ripening stages(S1, green ripe; S2, representing Lingwuchangzao with red surface area of 25%–50%; S3, 50%–75%; S4, 100%) and related antioxidant activities were investigated. The contents of total phenols, total flavonoids and phenolic compositions, and antioxidant properties including the abilities to inhibit lipid peroxidation and scavenge 2,2-diphenyl-1-picrylhydrazyl(DPPH) and reducing power were investigated. The results showed that the content of phenolic compounds had a significant correlation with antioxidant activities. The contents of total phenols varied from 2 996.60 to 5 801.84 μg/g and the contents of total flavonoids were in the range of 33.12 to 122.12 μg/g. Jujubes at stage S1 showed the highest level of total phenols. The main phenolic compounds of during different ripening stages of Lingwuchangzao jujubes were detected. The antioxidant capacity was significantly correlated with the contents of total flavonoids and total phenols(P < 0.05). Jujubes at stage S1 exhibited the highest antioxidant activity and at stage S4 presented the lowest one. These results showed that the extracts of Lingwuchangzao jujubes at stage S1 had high free radical scavenging activity as a potent natural antioxidant with commercial value. The antioxidant performance of Lingwuchangzao jujubes at the green ripe stageis better than at other ripening stages. Jujubes at the green ripe stage may be more suitable to gain natural antioxidants.