银耳多糖与大豆分离蛋白的相互作用及流变性能

研究银耳多糖（Tremella fuciformis polysaccharide，TFP）与大豆分离蛋白（soybean protein isolate，SPI）的相互作用，利用浊度、纳米粒度仪、激光共聚焦扫描显微镜、流变仪、荧光光谱法和傅里叶变换红外光谱法等对TFP与SPI的复合凝聚过程进行表征。结果表明：pH值、SPI与TFP质量比和盐离子浓度对凝聚体的形成影响较大，当SPI∶TFP＞1时，与复合物形成相关的关键pH值（pHc和pHφ1）向高pH值方向移动。当SPI∶TFP＜1时，pHφ1向低pH值方向移动。随着体系中TFP比例的增大，浊度的最大吸收峰逐渐降低（pHopt逐渐减小）。当SPI∶TFP＝1∶1时，两者在pH 3.0处的相互作用最强，此时体系总体的黏度最大（约为1.30 Pa·s），形成的聚集体最多且粒径最大。NaCl浓度较低（＜20 mmol/L）时能促进SPI-TFP凝聚体形成，NaCl浓度较高（≥20 mmol/L）时由于屏蔽作用会抑制凝聚体的形成。当剪切频率10 Hz、NaCl浓度20 mmol/L、SPI与TFP质量比1∶1时，体系具有最高的黏弹性模量，储能模量为9.24 Pa，损耗模量为3.40 Pa。本研究为TFP在植物蛋白饮料中的开发和应用提供了一定理论基础。

Interaction between Tremella fuciformis Polysaccharide and Soybean Protein Isolate: Rheological Properties of Their Mixtures

In order to study the interaction between Tremella fuciformis polysaccharide (TFP) and soybean protein isolate (SPI), the complex coacervation process between them was characterized by turbidity measurement as well as using a nano particle size analyzer, a laser confocal scanning microscope, a rheometer and Fourier transform infrared (FTIR) spectroscopy. The results showed that pH, the ratio of SPI to TFP and salt concentration had great influence on the formation of coacervates. When the SPI/TFP ratio was larger than 1, the critical pH associated with complex formation (pHc and pHφ1) shifted to higher pH. When the SPI/TFP ratio was less than 1, pHφ1 shifted to a lower level. The maximum absorption peak for turbidity gradually decreased (pHopt gradually decreased) with increasing level of TFP. When the SPI/TFP ratio was 1, the interaction between them was the strongest at pH 3.0, and the viscosity of the system was the largest (1.30 Pa·s). In addition, the largest amount of coacervates was formed with the largest particle size. The formation of SPI-TFP coacervates was promoted by low salt concentrations (c(NaCl) < 20 mmol/L) but inhibited by high salt concentrations (c(NaCl) ≥ 20 mmol/L) due to shielding. When the shear frequency was 10 Hz, the NaCl concentration was 20 mmol/L, and the SPI/TFP ratio of 1:1, the highest viscoelastic modulus was obtained, along with storage modulus of 9.24 Pa and loss modulus of 3.40 Pa. This study may provide a theoretical basis for the application of TFP in plant protein based beverage.