新疆不同红枣品种的总酚含量和抗氧化能力比较

Phenolic Profiles and Antioxidant Activity of Different Jujube Cultivars in Xinjiang

为了研究新疆红枣的遗传多样性,寻找抗氧化能力较强的功能性红枣品种,为保护利用红枣资源提供基础,用Folin-Ciocalteau法测定了7个品种红枣甲醇提取液中的总酚含量,采用体外法评价了红枣甲醇提取物的总抗氧化能力及对DPPH·和羟基自由基(·OH)的清除能力。结果表明:7个参试红枣品种都具有强抗氧化性,并且大多数品种间差异显著,其中哈密大枣、骏枣、灰枣的抗氧化能力较强;不同品种间的总酚含量差异较大,变化值为751.25 mg/100g,其中哈密大枣中含量最高是1 837.48 mg/100g,新疆小圆枣的总酚含量最低为1 086.23 mg/100g;相同品种中果肉和果核间总酚含量差异较大,果肉总酚含量约为果核的6倍。各种抗氧化指标与总酚含量呈显著正相关,酚类物质是红枣抗氧化的重要物质基础之一。

In order to provide basic information for exploring strong antioxidant jujube resources in Xinjiang, three different methods were used to evaluate antioxidant activities of 7 jujube cultivars including total antioxidant activity, hydroxyl radical scavenging and DPPH·radical scavenging. Results showed that 7 jujube cultivars had strong antioxidant capacities, and there was significant difference among most cultivars. Hami jujube, Junzao and huizao＇s antioxidant capacities were the strongest in all cultivars. Total phenol contents varied considerably among cultivars by Folin-Ciocalteau method, Hami jujube having the most 1 837.48 mg/100 g and Xiaoyuanzao having the least 1 086.23 mg/100 g. Total phenol contents have large differences in the pulp and core, pulp total phenol content is about 6 times of the core of the fruit. Three indexes of antioxidant activity and total phenolic contents were significantly correlated, whereas phenolics is one of the most important materials of antioxidant activity of jujube.