苦丁茶冬青多糖流变学特性研究

Rheological properties of polysaccharide isolated from Ilex kudingcha C.J.Tseng

以苦丁茶冬青多糖(ICP)为对象,研究浓度、剪切力、温度、p H、冻融变化和盐离子浓度等因素对ICP溶液表观粘度和粘弹性的影响。结果显示,ICP溶液表现出"非牛顿流体"特性,具有良好的抗降解性能;ICP多糖溶液的表观粘度随p H的变化而变化;冷藏和冷冻对ICP溶液的粘度基本无影响,ICP溶液的粘度随着温度的升高而下降;高浓度的Na^+、K^+、Mg^(2+)和Ca^(2+)四种盐离子可使ICP溶液的粘度明显下降。动态流变实验结果显示,应变控制在100%以内时,ICP的弹性储能模量G'基本没有变化,ICP溶液的储能模量G'始终大于损耗模量G″,表现出凝胶特性,且G'和G″随Na^+、K^+和Mg^(2+)的添加呈降低趋势。因此,ICP溶液的流变特性受浓度、温度、盐离子等因素的影响。

Effects of concentration, shear force, temperature, pH, freezing-thawing and addition of metallic ions on the apparent viscosity and viscoelasticity of polysaccharide isolated from llex kudingcha C.J.Tseng（ICP） were studied.The results showed that the aqueous ICP solution was a typical non-Newtonianfluid with good anti-degradation property.The pH value affected the apparent viscosity of ICP solution. Freeze- thawing had little effect on the apparent viscosity of ICP solution. However, the apparent viscosity decreased along with the increase of temperature and addition of metallic ions （Na^＋, K^＋ and Mg^2＋ ）.The dynamic rheological results showed that the storage modulus G＇ hadchanged slightly within 100% strain rate, and the storage modulus G＇ were always higher than loss modulus G＂.G＇ and G＂decreased along with theaddition of metallic ions（ Na^＋, K^＋ , Mg^2＋ and Ca^2＋） .These results suggested that concentration, temperatureand addition of metallic ions could affect the rheological property of ICP solution.