假肠膜明串珠菌胞外多糖的构象特征及理化性质和生物活性研究  

Conformational characteristics,physicochemical properties and biological activity of exopolysaccharide produced by Leuconostoc pseudomesenteroides

作　　者：王斌斌 周志江[2] 韩烨[2] WANG Binbin;ZHOU Zhijiang;HAN Ye(School of Life Science,Shanxi Normal University,Taiyuan 030000;School of Chemical Engineering and Technology,Tianjin University,Tianjin 300354)

机构地区：[1]山西师范大学生命科学学院,太原030000 [2]天津大学化工学院,天津300354

出　　处：《中国食品添加剂》2022年第5期1-10,共10页China Food Additives

基　　金：国家科技支撑计划课题(2015BAD16B01);天津市科技计划项目(19YFZCSN00100)。

摘　　要：以假肠膜明串珠菌Leuconostoc pseudomesenteroides PC胞外多糖(Expolysaccharides,EPS)为研究对象,运用X射线衍射光谱技术和刚果红、圆二色光谱、β-消除反应方法分析PC EPS构象特征,并对其水溶解性、Zeta电位、特性黏度、乳化性和体外益生性进行综合分析。结果表明,PC EPS总体结晶度较低,主要以大量无定型态形式存在,且呈单股无规则线团形式,其链构象不受浓度影响;该多糖糖肽键连接键型为O型,多糖水溶解指数为96%。当PC EPS浓度从0.125增大至2mg/mL时,其Zeta电位值从-2.7±0.1mV变为-7.3±0.2mV,绝对值增大、溶液的稳定性逐渐增强。另外,PC EPS在双蒸水中的特性黏度为238.27mL/g;2.0mg/mL PC EPS对大豆油和葵花籽油的乳液活性分别为(57.57±0.13)%和(54.17±0.06)%,72h后其对大豆油、葵花籽油和花生油的乳化能力仍保持最初活力的50.6%、54.2%和52.1%。体外益生性实验显示,在添加2g/L PC EPS培养基中,Lactobacillus delbrueckii与Lac.paracasei的最大生长量较对照组分别增加约25.5%和19.8%;Lac.casei的生长对数期提前约12h;Lac.plantarum的最大生长量增加、延滞期缩短。综上所述,PC EPS具有极高水溶解性、较强的植物油乳化性、溶液体系稳定性,为其在食品工业中用作增稠剂、稳定剂和益生成分添加剂提供了理论依据。Exopolysaccharides(EPS)made from Leuconostoc pseudomesenteroides PC was studied,its conformational characterization of PC EPS was analyzed by X-ray diffraction spectroscopy,Congo red staining,circular dichroism spectroscopy andβ-elimination.The water solubility,Zeta potential,intrinsic viscosity,emulsifying properties and in vitro probiotic properties of PC EPS were also analyzed.The overall crystallinity of PC EPS was low and structure was amorphous.It was composed of a single strand of irregular coils and its chain conformation was not affected by the concentration.The glycopeptide bonds linkage is an O-form and its water solubility index is 96%.When the concentration was increased from 0.125 to 2mg/mL,Zeta potential of PC EPS solutions decreased from-2.7±0.1mV to-7.3±0.2mV.As the absolute value increased,the stability of the solution also gradually increased.In addition,the intrinsic viscosity of the PC EPS in water was 238.27mL/g.PC EPS showed a high emulsifying activity with soybean oil(57.57±0.13%)and sunflower seed oil(54.17±0.06%).After 72 h,its emulsifying ability with soybean oil,sunflower oil and peanut oil remained above 50.6%,54.2%and 52.1%of their initial values,respectively.In vitro probiotic experiments,compared with the control group,adding 2g/L PC EPS increased the maximum biomass of Lactobacillus delbrueckii and Lac.paracasei by 25.5 and 19.8%,respectively.The PC EPS group also shortened the lag phase of Lac.casei by 12 hours,increased the maximal biomass and shorten the lag phase of Lac.plantarum.In summary,PC EPS has excellent water solubility,strong vegetable oil emulsification ability and good stability.It has great potential as a thickener,stabilizer and prebiotic additive in food industry.

关 键 词：假肠膜明串珠菌 胞外多糖 构象 理化性质 生物活性 

分 类 号：TS202.1[轻工技术与工程—食品科学] TS201.7[轻工技术与工程—食品科学与工程]