Studies on the mechanism of texture improvement by polysaccharide additions to Surimi gels using particle tracking and NMR

通过流变学、粒子跟踪、光镊等宏观、微观和分子观察手段，研究了多糖作为增稠剂改善鱼糜凝胶品质的机理。研究了不同多糖对鱼糜凝胶宏观性质的影响。对照凝胶显示出低模量，但随着多糖的添加而增加。对于淀粉增强鱼糜凝胶，添加低淀粉浓度显示出与对照凝胶相似的模量。然而，在较高浓度下观察到模量的增加，表明淀粉从蛋白质凝胶网络中吸收水，增加蛋白质凝胶相中的蛋白质浓度。另一方面，一个明显的增加模量观察KC增强鱼糜凝胶与和不添加KCl，即使在低多糖浓度。KC更可能是作为一种功能性填料，通过亲水胶体的阴离子基团和带正电荷的蛋白质与鱼糜蛋白质相互作用。角叉菜胶凝胶的时间依赖性弛豫是通过在大应变下使颗粒移位直到颗粒从捕获物中释放并跟踪释放的颗粒的反冲来测量的。不同角叉菜胶凝胶颗粒反冲力的应力松弛表明凝胶的微观流变特性具有非线性特征。

The mechanism of polysaccharide addition as a reinforcer to improve Surimi gels' quality was investigated by macroscopic, microscopic, and molecular observation using rheological measurements, particle tracking, and optical tweezers. The macroscopic property of Surimi gels with different polysaccharides was evaluated. The control gel showed a low modulus but increased with the addition of polysaccharides. For starch reinforced Surimi gels, the addition of low starch concentration showed similar moduli with the control gel. However, an increase in the moduli was observed at higher concentrations, suggesting that starch absorbed water from the protein gel network, increasing the protein concentration in the protein gel phase. On the other hand, an apparent increase in the moduli was observed for KC reinforced Surimi gels with and without the addition of KCl even at low polysaccharide concentration. It is more likely that KC acted as a functional filler that interacts with the Surimi proteins via the anionic groups of the hydrocolloid and the positively charged proteins.Microscopic measurement using particle tracking and optical tweezer was performed to investigate the gels' local physical property. The time-dependent relaxation of carrageenan gels was measured by displacing the particle at a large strain until the particle was released from the trapped and tracking the recoil of the released particle. The stress relaxation of the particles' recoil for the different carrageenan gels suggests nonlinear features of the gels' microrheological properties.