酸枣水提物不同提取工艺优化及抗氧化活性研究

Optimization of different extraction processes of sour jujube juice and study on its antioxidant activity

以酸枣为研究对象,优化超声法、酶解法、超声辅助酶解法3种提取方法工艺参数,并比较3种提取方法提取物总酚、总糖含量及抗氧化活性。采用响应面法优化提取工艺,利用ABTS自由基、DPPH自由基和羟自由基清除试验评价酸枣汁的抗氧化活性。结果表明,在最佳提取工艺条件下超声法提取率为67.37%;酶解法提取率为69.47%;超声辅助酶解法提取率为74.49%。其中超声辅助酶解法的最佳提取工艺参数为:液料比131(mL/g),加酶量2.1%(以果肉粉末总重计),酶解时间1.2h,超声时间29min,超声功率146W。不同提取方法对酸枣汁中的总酚含量没有显著影响,与超声法、酶解法相比,超声辅助酶解法可以显著提高酸枣汁中总糖含量。体外抗氧化试验表明酸枣汁具有较高的抗氧化活性,并且超声辅助酶解法提取的酸枣汁抗氧化能力高于其他两种方法,表明超声辅助酶解法可以作为一种对酸枣果肉水溶性物质高效提取的方法。

The effect of three different methods,including ultrasonic extraction,enzymatic extraction and ultrasound-assisted enzymatic extraction,and the extraction of sour jujube juice was optimized.Moreover,the total phenol,total sugar content and antioxidant activity of the extracts were compared.The response surface method was used to optimize the extraction process,and the antioxidant activity of jujube juice was evaluated by ABTS scavenging,DPPH scavenging and hydroxyl radical scavenging test.The results demonstrated that under the control of the optimal conditions,the extraction rates of ultrasonic method,enzymatic method and ultrasonic-assisted enzymatic hydrolysis were67.37%,69.47% and 74.49%.The optimal ultrasonic-assisted enzymatic hydrolysis extraction technology was:liquid-solid ratio131(mL/g),enzyme amount 2.1%(based on the total weight of pulp powder),enzymolysis time 1.2 h,ultrasonic time29 min,and ultrasonic power 146 W.Different extraction methods had no significant effect on the total phenolic content in jujube juice.Compared with ultrasonic and enzymatic methods,ultrasonic assisted enzymatic method could significantly increase the total sugar content in jujube juice.The antioxidant test showed that the jujube juices of different extraction methods had high antioxidant activity,and the antioxidant capacity of the jujube juice extracted by ultrasound-assisted enzymatic method was higher than the other two ones.This indicated that the ultrasonic assisted enzymatic hydrolysis method could be used as a method for efficiently extracting water-soluble substances from jujube pulp.