魔芋胶溶液浓度对其流变学特性的影响研究

Effects of concentrations of konjac glucomannan solutions on their rheological properties

目的研究魔芋胶溶液浓度对其流变学特性的影响。方法配制质量分数为0.1%~1.0%的魔芋胶溶液,通过稳态流动、应变扫描、频率扫描以及粘弹性-温度扫描、粘度-温度扫描研究粘度特性随剪切速率及温度的变化情况,粘弹性随应变、频率及温度的变化及考察模量相交点、松驰时间等与结构特性相关的各因素。结果在0.1%~1.0%浓度范围内,魔芋胶溶液的零剪切粘度、粘度、剪切稀化指数、特征松驰时间及弹性模量、粘性模量、损耗正切与浓度之间存在较高的相关性。另外,浓度的改变影响频率扫描中G’=G’’时的频率、模量及松驰时间,亦影响粘弹性-温度扫描中凝胶-溶胶转换时温度的高低与模量的大小。结论魔芋胶溶液的浓度明显影响其流变学特性,在实际应用中可根据需要选择合适的浓度进行使用。

Objective To investigate the effect of konjac glucomannan solution concentrations on its rheological properties. Methods The konjac glucomannan solutions with the mass fraction of 0.1%-1.0% were prepared. The viscosity characteristics changing with shear rates and temperatures, the viscoelasticity changing with strain, frequency and temperature, and the modulus intersection point and relaxation time were studied through steady-state flow, strain sweep, frequency sweep and viscoelasticity-temperature sweep. Results Within the concentration range of 0.1%-1.0%, there was a high correlation between the zero shear viscosity, viscosity, shear thinning index, characteristic relaxation time and elastic modulus, viscous modulus, and loss tangent of konjac glucomannan solutions and the concentration. In addition, the change of concentration affected the frequency, modulus and relaxation time when G’=G’’ in the frequency sweep, and also affected the temperature and modulus during the gel-sol conversion in the viscoelastic-temperature sweep. Conclusion The concentration of konjac glucomannan solutions obviously affects its rheological properties, which can be used according to the needs in practical application.