金钱菇多糖的流变学性质研究
Rheological properties of Jinqian mushroom
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摘要: 从金钱菇子实体水提残渣中纯化获得了一个多糖组分JQPs,采用DHR-3型旋转流变仪研究了JQPs溶液流变学性质,为其在食品工业中的应用提供理论支持。静态流变学实验结果表明,JQPs溶液流动指数n<1,为假塑性流体,浓度越高其假塑性越明显。通过对溶液流动曲线的拟合,发现幂律方程可以作为描述JQPs溶液流动曲线的模型;动态粘弹性实验表明JQPs溶液的G’和G″在1100rad/s扫描频率下与测试浓度和测试温度均具有一定的相关性。一定温度下,随着浓度的增加,G’的增加速率超过G″,当浓度达到2.0%时曲线重合,开始形成弱凝胶。浓度为2.5%的JQPs溶液的G’和G″随着温度的升高而逐渐减小,在15℃时基本重合,开始形成弱凝胶。Abstract: A polysaccharide fraction JQPs was isolated and purified from Jinqian mushroom. In this study,the rheological properties of polysaccharide of JQPs were investigated.The viscoelastic properties were determined as a function of concentration and temperature by using rheometer. The results showed that the JQPs solution exhibited pseudoplastic flow behavior.The low concentration solution exhibited almost Newtonian flow behavior at low shear rate region. With the increase of shear rate,the viscosity decreased and the non- Newtonian behavior became more and more obvious.The storage modulus G' and loss modulus G″ were in correlation with temperature and frequency.With the increase in polysaccharide concentrations,the G' increased more rapidly than the G″. At the concentration of 2.0%,the polysaccharide solution showed weak gel behavior. With the increase in polysaccharide temperature,the G' decreased more rapidly than the G″,the polymer solution( 2.5%) revealed weak gel behavior at 15℃. The study could provide theoretical foundation and reference for JQPs application in food industry.