刺云实胶/魔芋葡甘聚糖复合凝胶流变性能研究

Research on Rheological Properties of Tara Gum/Konjac Glucomannan Blend Hydrogel

摘要:

为了获得性能更优良的食品凝胶体系，本研究将刺云实胶(TG)与魔芋葡甘聚糖(KGM)按一定比例复配制得复合凝胶，通过旋转流变仪研究其流变性能，用统计力学和动力学相结合的方法，对KGM与TG分子链的链间作用进行深入研究。实验结果表明，TG/KGM凝胶在高温下为假塑性流体,二者具有良好的相容性，复配溶胶体系的剪切应力和黏度均随着KGM组分比例的增加而增加，抗剪切能力有所增强。在选定的频率范围0.1~100 rad/s内，TG/KGM的损耗模量G”低于其储能模量G’，KGM的添加使得模量上升。而在85~25℃的降温过程中，随着KGM的增加，复配体系中G’和G”模量下降，溶胶向凝胶的转化温度点发生右移，以上表明相比于单一多糖，适量的KGM与TG复配，可以大大提高凝胶耐热性，形成稳定性高的凝胶。分析得出，在不同质量比的TG/KGM凝胶体系中，当m(TG):m(KGM)=0.9:0.6（即TK6）时，可得到综合性能优异、胶凝能力强、稳定性高且黏度适中的凝胶体系。研究表明，制备的TG/KGM凝胶有望成为一种新型食品凝胶，可以为TG和KGM的合理应用提供理论指导。

Abstract:

In order to obtain blend hydrogel system which has better performance and is more suitable for applying in food industry, rheological properties of Tara Gum/Konjac Glucomannan (TG/KGM) gel system in different proportion were studied by rotational rheometer in this research, the interaction between KGM molecular chain and TG molecular chain was studied by means of statistical mechanics and dynamics as well. Result reveals that TG/KGM gel behaved like pseudoplastic fluid at high temperature and the two polymers had good compatibility. The shear stress, viscosity and shear resistance all increased with the increase of the proportion of KGM. In the selected frequency range 0.1~100 rad/s, the loss modulus G”of TG/KGM is lower than storage modulus G ', and the addition of KGM caused both modulus rised. However, during the cooling process of 85~25℃, G 'and G' modulus decreased with the increase of the proportion of KGM, and the conversion temperature of sol to gel gradually increased, Thus, it is showed that compared with the single polysaccharide, the proper proportion of TG/KGM could greatly improve the heat resistance and form the gel with higher stability. Especially when m(TG):m(KGM)=0.9:0.6 (TK6), a gel system with more excellent comprehensive properties, higher gelling ability, higher stability and more moderate viscosity can be obtained. This kind of TG/KGM gel is expected to become a new type of gel applying in food industry, which can provide theoretical guidance for the rational application of TG and KGM.