不同提取方法对荔枝干粗多糖提取率及其自由基清除活性的影响

目的]通过比较提取率和抗氧化活性,从3种多糖提取方法中筛选出适合荔枝干多糖的提取方法。方法]优化热水浴、微波超声协同和纤维素酶活法各提取参数条件,比较三者在多糖得率、含量以及对ATBS和DPPH自由基清除方面的差异。结果]热水浴法多糖提取率随温度升高而逐渐增加,但温度较高时其升幅降低;微波超声协同法液料比变化对提取率有影响,但提升幅度较小;纤维素酶活法也存在类似现象。在最优条件下纤维素酶活法具有最低的提取率和最高的多糖比率。另外,纤维素酶提取法所得多糖清除ATBS自由基能力较强,其次为热水浴法,最后为微波超声协同法。结论]热水浴法具有提取率高、操作简便、多糖含量和抗氧化活性较高等优势,更适合于荔枝干多糖的提取。

Effecto f Dif ferent Extraction Me thods on the Extratc ion Rate and Free Ra dical Scavenging Capacti y of Dry Litchi Crud e Polysaccha-ride

Objective] In order to screen an extraction method for dry litchi, three different polysaccharide extraction methods were compared with their extraction rate and antioxidant activity.Method] The parameters of conventional hot water, microwave-ultrasounic coordination and cellulose methods were optimized to reach optimal yield.Then the crude polysaccharide, polysaccharide content and their DPPH and ATBS scav-enging capacity were compared. Result] In conventional hot water method, the extraction rate was increased with the improvement of tempera-ture.But at the high temperature stage, the increase was limited;in microwave-ultrasonic coordination method, the change ratio of liquid to mate-rial also had effect on extraction rate;the similar phenomenon was also found in cellulose method , which had the lowest extraction rate, but the highest polysaccharide rate.The antioxidant activity test showed that the polysaccharide from cellulose extraction method had the strongest ATBS free radical scavenging activity, then the conventional hot water and microwave-ultrasonic coordination method.But a little difference was found in DPPH test, due to the increase activity from microwave-ultrasonic coordination method.Conclusion] Due to the highest extraction rate, easy op-eration, higher polysaccharide content and antioxidant activity, the conventional hot water method was fit to dry litchi polysaccharide extraction.