大连刺参多糖的提取纯化及体外抗氧化活性研究

以大连刺参为原料,多糖提取率为指标,通过单因素实验和响应面试验法优化木瓜蛋白酶提取刺参多糖的酶解工艺条件;以蛋白脱除率为指标,通过单因素实验和正交试验法,优化D-葡萄糖酸-δ-内酯(GDL)对刺参多糖的脱蛋白工艺;并检测经过提取纯化后的刺参多糖的体外抗氧化活性。结果表明,刺参多糖的最佳提取工艺为:加酶量1.60%、pH7.30、温度54.0 ℃,在此条件下刺参多糖提取率为5.34%;最佳脱蛋白工艺条件为:反应温度60 ℃、反应时间2 h、GDL溶液(w/w,20%)加入量2.5 mL,蛋白脱除率为95.8%。提取纯化的刺参多糖清除DPPH自由基、羟自由基、超氧阴离子和ABTS自由基的IC₅₀分别为0.3、4.5、3.9、0.85 mg/mL。刺参多糖浓度为3.0 mg/mL时,ABTS+自由基的清除能力最强,达到90.4%,且与阳性对照V_C的清除能力相差不大。说明刺参多糖具有较好的体外抗氧化活性。

Extraction,Purification and Antioxidant Activities in Vitro of Polysaccharide from Dalian Sea Cucumber (Stichopus japonicus)

Polysaccharide was extracted from sea cucmber (Stichopus japonicus) by enzymolysis method, and the enzymatic conditions of papain were optimized through the single factor and response surface methodology by using the yield of polysaccharide as the index. The results showed that the optimal extraction conditions of polysaccharide were as follows:Enzyme dosage 1.60%, pH7.30, temperature 54.0℃. Under these conditions, the yield of polysaccharide was 5.34%. D-glucono-δ-lactone (GDL) was further used for the deproteinization of polysaccharide, and the deproteinization process was optimized with single factor and orthogonal experiment. The optimal conditions for deproteinization were as follows:Reaction temperature 60℃, reaction time 2 h, addition of GDL solution (w/w, 20%) 2.5 mL. The protein removal rate reached 95.8% under optimal conditions. The IC₅₀ of DPPH, hydroxyl free radical, superoxide anion and ABTS+ free radical were 0.3, 4.5, 3.9 and 0.85 mg/mL, respectively. When the concentration of sea cucumber polysaccharide was 3.0 mg/mL, ABTS free radical scavenging ability was the strongest, reached 90.4%, and the scavenging ability was similar to that of V_C. Therefore, the polysaccharide would have good antioxidant capacities in vitro.