三七多糖酶解提取工艺优化及抗氧化活性

Optimization of Enzymolysis Extraction Process and Antioxidant Activity of Panax notoginseng Polysaccharides

以提取率为指标,酶解温度、酶解时间及酶添加量为变量,采用单因素与正交试验优化α-淀粉酶提取三七多糖(Panax notoginseng polysaccharides,PNP)工艺;采用苯酚-硫酸法、间羟基联苯法、Bio-Rad微量蛋白法、1-苯基-3-甲基-5-吡唑酮柱前衍生高效液相色谱(1-phenyl-3-methyl-5-pyrazolone pre-column derivatization high performance liquid chromatography,PMP-HPLC)法分别测定PNP的理化性质和单糖组成;以DPPH·、ABTS+·和羟基自由基清除率为指标,分析PNP抗氧化活性。结果表明,最佳工艺为酶解温度60℃、酶解时间2 h、酶添加量4%,此时PNP提取率为6.45%、PNP总糖含量67.33%、糖醛酸含量13.47%、蛋白质含量12.00%、单糖组成及摩尔百分比分别为葡萄糖79.06%、半乳糖8.23%、半乳糖醛酸6.33%、阿拉伯糖5.07%、鼠李糖1.31%;对于3种自由基,PNP的清除能力低于抗坏血酸,但均呈现不同程度的清除作用,并且清除率均与浓度呈正相关,具有抗氧化活性。

With the extraction rate as the objective and the enzymolysis temperature,enzymolysis time,and en-zyme dosage as variables,the process ofα-amylase-assisted extraction of Panax notoginseng polysaccharides(PNP)was optimized by single factor and orthogonal test.The physicochemical properties and monosaccharide composition of PNP were determined by the phenol-sulfuric acid method,m-hydroxybiphenyl method,Bio-Rad microprotein method,and 1-phenyl-3-methyl-5-pyrazolone pre-column derivatization high performance liquid chromatography(PMP-HPLC)method,respectively.The antioxidant activity of PNP was analyzed with DPPH·,ABTS+·,and hydroxyl radicals as indicators.The results showed that the optimum conditions were as follows:enzymolysis temperature of 60℃,enzymolysis time of 2 h,and enzyme dosage of 4%.The extraction rate was 6.45%.The total sugar content of PNP was 67.33%;the uronic acid content was 13.47%;the protein content was 12.00%,and the monosaccharide composition and mole percentage were glucose(79.06%),galactose(8.23%),galacturonic acid(6.33%),arabinose(5.07%),and rhamnose(1.31%),respectively.For three kinds of free radicals,PNP had a lower scavenging ability than ascorbic acid,but all of them had different scav-enging effects,and the scavenging rate was positively correlated with the concentration,so it had antioxidant activity.