葛仙米多糖理化性质和流变学特性的研究

Physicochemical Properties and Rheological Properties of Nostoc sphaeroids Kütz Polysaccharide

为研究葛仙米多糖的流变学特性,以室内培养的葛仙米为原料,通过水提醇沉法得到葛仙米多糖;采用MCR-302型旋转流变仪考察质量浓度、酸碱性、温度、V_C和H_2O_2对多糖溶液表观黏度的影响,探究多糖溶液在扫描频率范围内的动态黏弹性,来反映其流变学特性。结果表明:其多糖含量为96.95%、重均分子量为1.324×10~5Da、由阿拉伯糖、半乳糖、葡萄糖、木糖、甘露糖及葡萄糖醛酸组成;葛仙米多糖溶液是假塑性非牛顿流体,具有剪切稀释的特性;溶液黏度随质量浓度的增大而增加;在20~80℃内,溶液黏度随着温度的升高而降低;溶液p H=3.0和p H=11.0时的黏度小于p H=7.0;V_C和H_2O_2可以降低多糖溶液的黏度;在扫描频率0.1~10 Hz内,储能模量(G')和损耗模量(G″)随葛仙米多糖溶液质量浓度的增加而增大。此外,葛仙米多糖与透明质酸具有协效增稠性。

In order to study the rheological properties of the Nostoc sphaeroids Kütz polysaccharide,the cultivated-indoor of Nostoc sphaeroids Kütz as raw materials,taking the Nostoc sphaeroids Kütz polysaccharide by water extraction and alcohol precipitation method as the research object.Using MCR-302 type rotary rheometer to investigate the effects of concentration,pH,temperature,VCand H2O2on the apparent viscosity of polysaccharide solution and explore the dynamic viscoelasticity of polysaccharide solution in scanning frequency range to reflect its rheological properties.The results showed that the content of polysaccharide was 96.95%,the average molecular weight of polysaccharide was 1.324×10^5Da,the monosaccharide composition analysis showed that it was composed of arabia,glucos,galactose,xylose,mannose and glucuronic acid.Nostoc sphaeroids Kütz polysaccharide solution was pseudoplastic non-Newtonian fluid with shear thinning properties;The viscosity of Nostoc sphaeroids Kütz polysaccharide solution increased with the increasing concentration.In the range of 20～80℃,the viscosity of polysaccharide solution decreased with the increase of temperature.The viscosity of polysaccharide solution at pH=3.0 or pH=11.0 was lower than pH=7.0.VCand H2O2could reduce the viscosity of polysaccharide solution.The storage modulus（G＇）and loss modulus（G″）increased with increasing concentration of Nostoc sphaeroids Kütz polysaccharide solution in scanning frequency 0.1～10 Hz.In addition,Nostoc sphaeroids Kütz polysaccharide had synergistic thickening interaction with hyaluronic acid.