香菇多糖的微波预处理-超声波提取工艺及其抗氧化活性研究

MICROWAVE PRETREATMENT-ULTRASONIC EXTRACTION TECHNOLOGY OF LENTINAN FROM MUSHROOM AND ITS ANTIOXIDANT ACTIVITY

为了研究香菇多糖的微波预处理-超声波提取工艺及其体外抗氧化活性,以香菇多糖得率为考察指标,对解析剂比、微波时间、液料比、提取温度、提取时间进行单因素试验,在此基础上选取主要影响因素进行正交试验,优选微波预处理-超声波提取的最佳工艺条件;对所制备的香菇多糖进行分级醇沉,并以超氧阴离子自由基(O2-·)、羟基自由基(·OH)和1,1-二苯基-2-苯基自由基(DPPH·)清除能力评价其体外抗氧化活性。结果表明:香菇多糖提取的最佳工艺条件为:提取温度70℃,解析剂比6∶1,微波时间120 s,液料比35∶1,提取时间20 min,该工艺条件下香菇多糖得率达9.45%。香菇多糖具有一定的抗氧化活性,当香菇多糖质量浓度为2.5 mg/m L时,香菇多糖对O2-·、·OH和DPPH·清除率分别为45.25%、61.01%和76.12%。对香菇多糖进行分级醇沉结果表明香菇多糖主要成分为大分子多糖;对不同分级的多糖进行抗氧化活性研究表明大分子多糖抗氧化活性较小分子多糖强,即香菇多糖的抗氧化活性主要由大分子多糖决定。微波预处理-超声波提取技术具有省时高效的特点,能较好地保护多糖的抗氧化活性,特别适用于多糖类物质的提取。

Lentinan is the structural component of the cell wall,which has antioxidant,antibacterial,regulating immunity,anti-virus,anti-aging and anti-tumor and other biological activities. The present study was to investigate the microwave pretreatment-ultrasonic extraction technology of lentinan from mushroom and its antioxidant activity in vitro. The analytical agent ratio,microwave time,liquid to material ratio,extraction temperature,extraction time were studied by single factor test,while the lentinan yield was as evalution index. The extraction conditions was optimized through orthogonal experiments. Lentinan was classified into three degrees using alcohol precipitation method and their antioxidant activity was evaluated through the experiments of scavenging ability ofultra oxygen anion free radical（O-2·）,hydroxyl radicals（·OH）and 1,1-diphenyl-2-phenyl-free radical（DPPH·）,respectively. The results showed that the optimum extraction conditions were as follows：analytical agent ratio of6∶1（m L/g）,microwave time of 120 s,liquid to material ratio of 35 ∶1（m L/g）,extraction temperature of 70 ℃,extraction time of 20 min. Under the optimum conditions,the yield of lentinan was up to 9.45%. When the lentinan concentration was 2.5 mg/m L,the O-2·,·OH and DPPH· scavenging yields were 45.25%,61.01% and76.12%,respectively. The results of alcohol precipitation classification showed that the main ingredients of lentinan were macromolecular polysaccharide. The antioxidant activity of macromolecular polysaccharide was better than small molecules polysaccharide. The antioxidant activity of lentinan was mainly decided by macromolecular polysaccharide. The microwave pretreatment-ultrasonic extraction technology had the advantages of saving time,high efficiency and protecting the antioxidant activity of polysaccharide well,which was especially suitable for the extraction of polysaccharide substance.