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

采用流变学测量、颗粒跟踪、光学镊子等方法，从宏观、微观和分子观察等方面探讨了添加多糖作为增强剂提高鱼糜凝胶质量的机理。对含不同多糖的鱼糜凝胶的宏观性能进行了评价。对照凝胶的模量较低，但随着多糖的加入而增加。对于淀粉增强鱼糜凝胶，低浓度淀粉的加入量与对照凝胶的模量相似。然而，在较高浓度下观察到模量的增加，这表明淀粉从蛋白质凝胶网络中吸收水分，增加了蛋白质凝胶期的蛋白质浓度。另一方面，即使在低多糖浓度下，添加KCl和不添加KC增强鱼糜凝胶的模量也明显增加。更有可能的是，KC作为一种功能性填料，通过水胶体的阴离子基团和带正电的蛋白质与苏里米蛋白相互作用。利用粒子跟踪和光学镊子进行了微观测量，研究了凝胶的局部物理性质。通过在大应变下位移颗粒，直到颗粒从捕获中释放出来，并跟踪释放颗粒的后坐力，测量了卡拉胶凝胶的时间依赖性弛豫。不同角叉胶凝胶的微粒反冲应力弛豫表明了凝胶微流变特性的非线性特征。

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.