凌枣黄酮提取及自由基清除能力研究

Extraction technique and free radical scavenging activity of flavonoids prepared from Ling Jujube

对凌枣黄酮回流提取工艺和凌枣黄酮提取液的自由基清除能力进行了研究,凌枣黄酮回流提取的最佳工艺条件为:液固比30∶1(mL/g)、提取时间2h、提取温度75℃、乙醇浓度75%。在最佳提取条件下,凌枣黄酮的得率为5.01mg/g;三种体外抗氧化体系(还原力、羟自由基清除力及DPPH自由基清除力)结果表明,凌枣不同部位黄酮均具有抗氧化作用,作用大小呈浓度-剂量效应,在不同浓度范围内,不同部位凌枣黄酮的自由基清除能力顺序均为:枣肉黄酮>全枣黄酮>枣核黄酮>枣皮黄酮,结果表明凌枣果肉中含有较高活性或浓度的黄酮类组分,但凌枣各部位黄酮的自由基清除能力均低于同浓度的维生素C。

Reflux extraction technique and free radical scavenging activity of flavonoids of ling jujube were investigated. Optimum conditions were as follows.ratio of liquid to solid 30：1 （mL/g）, extraction time 2h, extraction temperature 75℃,75% of ethanol concentration, under the optimal conditions,fiavonoids yield of ling jujube flavonoid was 5. 01mg/g , three kinds of in vitro antioxidant system（reducing power,hydroxyl radical scavenging,and DPPH radical scavenging） results showed that flavonoid had different degree of antioxidant effects in different parts of ling jujube, the result showed a concentration-dose effect,in different concentration range,free radical scavenging activity of flavonoids from different parts of ling jujube was：flavonoids in the pulp〉flavonoids in entire Ling jujube〉flavonoids in the pit〉flavonoids in the peel,these results showed there were high activity or concentration flavonoids in ling jujube pulp,but free radical scavenging activity of different part of ling jujube were all lower than that of ascorbic acid.