铁皮石斛多糖酶解法提取工艺优化及抗氧化活性研究

Optimization of enzymatic extraction of polysaccharides from Dendrobium officinale and the antioxidant activity

目的:通过正交实验探究铁皮石斛多糖5种酶解法的最优提取工艺,并比较不同酶解法对铁皮石斛多糖相对分子质量、黏度以及抗氧化活性的影响。方法:以铁皮石斛为原料,用纤维素酶、果胶酶、淀粉酶、甘露聚糖酶、葡聚糖酶分别进行酶解条件的正交实验,对照传统水提法,对不同提取工艺下多糖的得率、相对分子质量、黏度、体外抗氧化能力进行比较和研究。结果:得到5种酶解法的最优提取工艺;不同提取方法按照多糖得率由高到低依次为:葡聚糖酶(55.41%)>果胶酶(53.12%)>纤维素酶(51.93%)>甘露聚糖酶(48.42%)>淀粉酶(46.90%)>水提多糖(38.76%);相比较于传统热水提取法,经酶解后提取所得多糖的相对分子质量和黏度均显著降低,其中淀粉酶降低相对分子质量作用稍弱;不同提取方法的多糖呈现不同的抗氧化能力,以果胶酶酶解的多糖抗氧化活性最强,总体优于传统水提法所得多糖。结论:酶解法显著提高多糖的提取率,所得多糖相对分子质量、黏度等物化性质显著降低且以果胶酶提取多糖的抗氧化活性最显著。不同酶解法对铁皮石斛多糖结构和连接方式的影响有待进一步探索。

Objective:To explore the optimal extraction process of five enzyme extraction methods for Dendrobium officinale polysaccharides(DOP)by using orthogonal method,and the effects of enzyme extraction on molecular weight,viscosity,and antioxidant activity of DOPs.Methods:Orthogonal experiments were conducted on polysaccharides enzyme extraction by using cellulase,pectinase,amylase,mannanase,and glucanase,respectively.Meanwhile,DOP was extracted by using traditional water extraction method.The yield,molecular weight,viscosity,and in vitro antioxidant capacity of polysaccharides from different extraction processes were evaluated.Results:Five optimal extraction processes for enzyme extraction method were obtained.The yield of polysaccharides obtained by different extraction methods were as follows:glucosidase(55.41%)>pectinase(53.12%)>cellulase(51.93%)>mannanase(48.42%)>amylase(46.90%)>water extraction(38.76%).Compared with traditional hot water extraction methods,the molecular weight and viscosity of polysaccharides obtained by enzyme extraction methods significantly reduced,and amylase had a slightly weaker effect on reducing molecular weight.Polysaccharides extracted by different methods exhibited different antioxidant abilities.Polysaccharides obtained by pectinase had the strongest antioxidant activity and overall superior to polysaccharides obtained by using traditional water extraction methods.Conclusion:Enzyme extraction methods significantly improved the extraction rate of polysaccharides,and the physicochemical properties such as molecular weight and viscosity significantly reduced.