大豆蛋白-大豆膳食纤维凝胶的流变特性

为研究恒定的蛋白纤维质量比及不同蛋白浓度对大豆蛋白复合大豆膳食纤维(SPI-SF)凝胶的影响,选用小形变振荡流变仪进行粘弹性测定,并以幂律模型分析流变数据。实验结果表明:SPI-SF的储能模量(G')和损耗模量(G")随蛋白浓度的增加大幅增加,且随时间的延长而逐渐增加;蛋白浓度3%的SPI-SF的G'G",而蛋白浓度4%~8%的SPI-SF的G'G",表明除蛋白3%的SPI-SF外其他SPI-SF均形成了凝胶。由幂律模型拟合得到相关系数n'和n',及参数A和z,由n'、n'的变化趋势可知,蛋白浓度4%~8%SPI-SF形成的凝胶为弱凝胶,且通过其参数A的增大、1/z的减小可知:随蛋白浓度的增加,SPI-SF凝胶的粘性减弱而弹性增强。

Rheological properties of the soybean protein-soybean dietary fiber gel

The rheological properties of soybean protein-soybean dietary fiber gel (SPI-SF) were determined using a mall deformation oscillation. The rheological data were analyzed with the power law models to study the effect of protein concentration on the gel with a constant mass ratio of protein and fiber. Results showed as follow. The storage modulus (G'') and Loss modulus (G") of all SPI-SF samples increased substantially as a gradual increase of the protein concentration; G'' < G" of the SPI-SF with 3% protein and G'' > G" of the SPI-SF with 4%-8% protein indicated that all SPI- SF formed gels except the SPI-SF with 3% protein. The correlation coefficients of n'' and n'', and the power law parameters of A and z were fitted by the power law model, and the trends of n'' and n'' indicated that SPI-SF gels of 4%-8% protein were weak. With an increase of parameter A and a decrease of parameter 1/z decreased, the viscosity became weaker and the elasticity became stronger in the SPI- SF gel along with an increase of the protein concentrations.