大豆分离蛋白及其与魔芋葡苷聚糖凝胶化作用的动态粘弹性研究

Dynamic Viscoelastic Studies on Gelation of Soybean Protein Isolate and Its Mixtures with Konjac Glucomannan

利用动态流变仪研究了胶凝时间、温度、频率及应变等因素对大豆分离蛋白及其与魔芋葡苷聚糖相互作用的动态粘弹性影响。实验结果表明:在高浓度下大豆分离蛋白与魔芋葡苷聚糖所形成的凝胶大都呈现出储存模量G′>损耗模量G″,表明凝胶动态模量中弹性的贡献已超过了粘性,溶液发生了凝胶化,并形成了三维交联的网络结构。碱性凝固剂的加入提高了凝胶的粘弹性。当频率在一定范围内变化时,未加碱样品其凝胶粘弹性在低频区可用频率依赖性来表征,而在高频区,加碱和未加碱样品其凝胶粘弹性不随频率变化而变化,都保持G′大于G″。

Interaction between konjac glucomannan （KGM） and soybean protein isolate （SPI） has been studied by means of dynamic viscoelastic measurements. The factors such as gelling time, temperature, frequency and strain were revealed in this study. The storage modulus G＇ was larger than the loss modulus G＂ for the gel mixtures of KGM and SPI at high concentration. It showed that the association of molecular chains and sol-gel transition was occurred and a three dimensional network was formed between KGM and SPI. An alkaline coagulant treatment for mixtures of KGM and SPI improved the viscoelastic properties of the gel. The frequency dependence of G＇ and G＂ for mixtures of KGM and SPI without alkaline at lower frequencies range from 10^-2 to 10^1 rad/s were observed, but at higher frequencies the frequency dependence of G＇ and G＂ for mixtures of KGM and SPI with or without alkaline were not confirmed in this study.