黑牛肝菌多糖提取工艺比较及其体外抗氧化活性研究

Study on comparative of polysaccharide extraction processes from Boletus aereus and their in vitro antioxidant activity

以得率为标准,从3种多糖提取方法(热水提取法、超声提取法、超声辅助复合酶法)中筛选并优化出黑牛肝菌多糖的最佳提取流程,进而获取黑牛肝功多糖体外抗氧化活性信息。利用单因素实验选出多糖得率最高提取法,利用响应面法进一步优化提取方法,采用分级醇沉法对多糖进行分级,采用DPPH自由基清除法、ABTS自由基清除法、羟自由基清除法以及还原力测定法了解黑牛肝菌多糖的体外抗氧化活性。结果发现:热水提取法、超声提取法、超声辅助复合酶提取法的多糖得率分别为5.64%、6.74%、18.47%。优化后的超声辅助复合酶提取法最佳工艺方案为:复合酶比例(m纤维素酶:m蛋白酶)2:1,酶解温度42.7℃,酶解时间67 min,酶添加量为1.92%,超声时间为20 min,预期得率18.867%;各级醇沉黑牛肝菌多糖均具有良好的抗氧化活性,抗氧化能力与多糖浓度和醇沉浓度呈正比,80%乙醇沉淀获得的多糖综合体外抗氧化活性最佳。超声辅助复合酶提取法可显著提高黑牛肝菌多糖得率,获得的黑牛肝菌多糖具有良好的体外抗氧化活性。

Using the yield as the standard,the optimal extraction methods for polysaccharides from Boletus aereus was screened and optimized among three extraction methods(hot water extraction,ultrasound extraction,and ultrasound-assisted composite enzyme method).Subsequently,the in vitro antioxidant activity of B.aereus polysaccharides was investigated.A single-factor assay was used to select the method with the highest polysaccharide yield.The response surface methodology was employed to further optimizing.Polysaccharides were graded using a stepwise alcohol precipitation method.The in vitro antioxidant activity was evaluated by DPPH assay,ABTS assay,hydroxyl free radical scavenging assay,and reducing power assay.The polysaccharide yields of hot water extraction,ultrasound extraction,and ultrasound-assisted composite enzyme extraction were 5.64%,6.74%,and 18.47%,respectively.The optimized process for ultrasound-assisted composite enzyme extraction was as follows:enzyme ratio(cellulase:protease)of 2:1,enzymatic hydrolysis temperature of 42.7℃,enzymatic hydrolysis time of 67 min,enzyme addition of 1.92%,ultrasound time of 20 min,and an expected yield of 18.867%.The B.aereus polysaccharides obtained exhibited excellent antioxidant activity.Their antioxidant capacities were positively correlated with polysaccharide concentration and alcohol precipitation concentration.The polysaccharides obtained by 80%ethanol precipitation showed the best overall antioxidant activity in vitro.Ultrasound-assisted composite enzyme extraction significantly improves the polysaccharide yield of B.aereus.The obtained polysaccharides exhibit excellent in vitro antioxidant activity.