绿豆多糖制备及抗氧化特性研究

摘要

采用响应面法对绿豆仁中多糖碱液提取工艺进行优化,在此基础上进一步开展分离纯化及抗氧化特性研究.结果表明,碱法提取绿豆多糖(Alkali extraction mung bean polysaccharides,AEMP)最佳工艺参数为碱液浓度0.02 mol/L,液料比20∶1 mL/g,提取温度50℃,提取时间3h,最终AEMP得率9.70 mg GE/g DW.进一步采用DEAE-2纤维柱和SephadexG-100凝胶柱分离纯化绿豆多糖,得到一个中性组分AEMP-1和一个酸性组分AEMP-2.抗氧化特性结果表明AEMP及其纯化组分对羟自由基和DPPH自由基均有良好清除效果,AEMP-2抗氧化活性最强,对羟自由基和DPPH自由基半数抑制浓度IC50值分别为4.71 mg/mL和1.03×10-1 mg/mL.表明绿豆多糖具有良好的抗氧化特性.%Response surface methodology ( RSM) was used to optimize the effects of processing parameters of alkali extraction on the yield of polysaccharides, and on the basis of which, anti - oxidative activity was investigated. The optimal extraction condition of polysaccharides was determined as follows with Alkali extraction mung bean polysaccharides ( AEMP) concentration of alkali solution was0.02 mol/L,ratio of water to raw material was 20:1 mL/g, extraction temperature was 50℃ and treatment time was 3. 0 h. Under this condition, the experimental recovery of crude alkali extraction mung bean polysaccharides (AEMP) was 9.70 mg GE/g DW. AEMP was purified by sepha-dex G - 100 gel chromatogarph after anion - exchange DEAE - 52 cellulose chromatograph. A neutral fraction ( AEMP - 1) and one acid fraction ( AEMP -2) were gained. The result of anti - oxidative activity showed that AEMP and its purified components showed excellent scavenging activity on the hydroxyl radicals and a, a - diphenyl - 1 - picryl-hydrazyl (DPPH) radicals. AEMP -2 had best radicals scavenging activity,and IC50 values was 4. 71 mg/mL (hydroxyl radicals) and 1.03×10-1 mg/mL (DPPH) ,respectively. Therefore,mung bean polysaccharides have a great anti - Oxidant activity.