山银花多糖提取工艺优化及其抗氧化活性研究

Optimization on extraction process of polysaccharide from Lonicerae flos and its antioxidant activity

目的:研究纤维素酶提取山银花多糖的最佳工艺条件,并探讨其体外抗氧化活性。方法:以山银花多糖得率为响应值,在单因素试验基础上,以酶解时间、液料比、酶解p H、酶添加量为试验因素,采用响应面法建立数学模型,筛选最佳提取工艺条件。山银花多糖抗氧化活性检测使用DPPH、·OH和O_2^-·自由基清除能力体系。结果:纤维素酶酶解提取山银花多糖最佳条件为:酶解时间80 min,液料比14.6 mL/g,酶解pH 5.2,酶添加量8.0 mg/mL,酶解温度50℃,在此条件下山银花多糖实际得率为15.76%,与理论预测值16.05%相对误差小于5%。液料比对多糖得率影响最显著,酶添加量、酶解pH次之,酶解时间影响最小。山银花多糖具有较强的抗氧化活性,对DPPH、·OH和O_2^-·自由基清除的半数抑制浓度IC_(50)分别为0.941、1.238、1.786 mg/mL。结论:获得山银花多糖纤维素酶酶法提取的最佳条件,该工艺条件方便可行,获得的多糖具有较强的自由基体外清除能力。

Objective:To optimize process extraction of polysaccharides from Lonicerae flos by cellulase enzymolysis approach and study its antioxidant activity in vitro. Methods:The mathematical model was established by response surface method(RSM)based on the results of single factor experiments;polysaccharides extraction rate was set as response value,and enzymolysis extraction time,ratio of water to material,pH value and cellulase concentration were experimental factors. Antioxidant activity of polysaccharides was evaluated by DPPH,·OH and O2-· free radical elimination method. Results:The optimum conditions obtained by RSM were as follows:enzymolysis extraction time 80 min,the ratio of water to feedstock 14.6 mL/g,pH value of enzymolysis 5.2,the cellulase concentration 8.0 mg/mL,enzymolysis temperature 50℃. Under the optimal conditions,the predicted extraction rate 16.05% was very close to the experimental extraction rate of 15.76%,the difference was less than 5%. The polysaccharide yield was most significantly affected by water to material ratio,followed by cellulase concentration,pH value of enzymolysis and extraction time. IC50 of DPPH,· OH and O2-· free radical were 0.941,1.238 and 1.786 mg/mL,respectively. Conclusion:The polysaccharide extraction process from Lonicerae flos by cellulase enzymolysis approach was convenient and feasible,and extracted polysaccharides had good free radical scavenging activity in vitro.