近江牡蛎膜分离联产制备多糖多肽及其功能特性研究

Co-production and functional property of polysaccharides from southern oyster Crassostrea rivularis by fractional ultrafiltration

为了联产制备近江牡蛎Crassostrea rivularis多肽多糖,提高近江牡蛎高值化利用率,采用不同截留分子量的超滤膜对近江牡蛎酶解液进行分级分离,并将酶解液分成相对分子质量为0~8000(CRRS-A)、8000~200000(CRRS-B)和>200000(CRRS-C)的3个组分,运用比色法、HPLC、UPLC-Q-Tof-MS/MS、傅立叶红外光谱法分别对3种组分的理化性质、体外抗氧化活性及其基本结构进行了分析。结果表明:CRRS-A组分主要由多肽组成,含量达到(87.26±1.65)%,相对分子量<2000,由10种化合物组成,具有较高的体外抗氧化活性,DPPH自由基、羟基自由基清除能力均较高,超氧阴离子清除能力显著高于抗氧化剂还原型谷胱甘肽(GSH),为(116.67±3.22)U/g;CRRS-B组分含有多糖(75.82±0.28)%,还含有己糖醛酸(5.06±0.60)%、甲基戊糖(31.23±1.29)%、硫酸基(23.47±0.70)%、氨基己糖(2.29±0.04)%等糖基,相对分子质量为8300~150000,为吡喃型多糖化合物,体外抗氧化能力总体优于2,6-二叔丁基-4-甲基苯酚(BHT),劣于抗氧化剂GSH;CRRS-C组分为吡喃型糖蛋白,相对分子质量为66000~7152000,体外抗氧化活性较差。研究表明,膜分离方法能对近江牡蛎多肽及多糖进行有效的分离,且近江牡蛎酶解液分级膜分离组分CRRS-A具有较高的体外抗氧化活性,CRRS-B具有高于BHT的体外抗氧化活性,该结果可为近江牡蛎高值化利用提供理论依据。

The hydrolysate was separated into three groups including 0-8000(CRRS-A),8000-200000(CRRS-B),and>200000(CRRS-C)from southern oyster Crassostrea rivularis by enzymatic hydrolysis combined with fractional ultrafiltration and the content,molecular weight(MW)distributions,physical and chemical properties,antioxidant activities and basic structure of each group were determined by colorimetric method,high performance liquid chromatography(HPLC),UPLC-Q-Tof-MS/MS,and Fourier infrared spectrum(FTIR).The results showed that the CRRS-A was primarily comprised of polypeptide(87.26±1.65)%,with MW of less than 2000 and containing 10 compounds.The maximal antioxidant activities including 2,2-diphenyl-1-picrylhydrazide(DPPH)free radical scavenging ability and hydroxyl radical scavenging ability were observed in CRRS-A,and the superoxide radical scavenging ability was significantly higher in CRRS-A than that in antioxidant glutathione(GSH)(116.67±3.22)U/g.The CRRS-B was found to contain polysaccharide(75.82±0.28)%,including glucuronic acid(5.06±0.60)%,methyl pentose(31.23±1.29)%,sulfate radical(23.47±0.7)%,and glucosamine hydrochloride(2.29±0.04)%,with MW of less than 8300-150000,assuming pyranose carbohydrate with high antioxidant activity varying between 2,6-di-tert-butyl-4-4-methylphenol(BHT)and GSH.The CRRS-C was pyranotype glycoprotein with a molecular weight of 6600-7152000 and had poor antioxidant activity in vitro.The findings indicated that fractional ultrafiltration system separated polypeptide and polysaccharide from southern oyster effectively and that the membrane separation components of enzymatic hydrolysates from southern oyster CRRS-A showed high antioxidant activity in vitro,CRRS-B showing better antioxidant activity than for BHT.