研究了表没食子儿茶素没食子酸酯(EGCG)对鲤鱼鱼糜凝胶理化流变学性质的影响。凝胶强度,纹理,持水量(WHC),水的动态分布,测定了添加不同水平(0、0.02、0.04、0.06、0.08和0.1%)EGCG的鱼糜凝胶的流变学特性。结果表明,随着EGCG含量的增加,凝胶强度,硬度,WHC,鱼糜凝胶的固定化水含量呈现先升高后降低的趋势,与对照相比,EGCG0.02%和EGCG0.04%显示出更好的凝胶性能。0.02%的EGCG凝胶强度最高(406.62g·cm),硬度(356.67克),WHC(64.37%),和固定水含量(98.958%)。当EGCG的量高于0.06%时,凝胶性能显著降低。粘度,G\',和G″的流变性能也表现出相同的趋势。鱼糜凝胶的化学相互作用,肌原纤维蛋白(MP)的二级结构,和EGCG与鲤鱼肌球蛋白的分子对接结果表明,EGCG主要通过氢键等非共价相互作用影响鲤鱼肌球蛋白的结构和聚集行为,疏水相互作用,和静电相互作用。EGCG0.02%和EGCG0.04%的微观结构致密均匀,具有较好的凝胶形成能力。较低浓度的EGCG通过与MP的适当交联形成了大量的化学相互作用,例如鱼糜凝胶内部的二硫键和疏水相互作用,并增加了MP的有序β-折叠结构,这促进了致密三维网络凝胶的形成。
The influence of epigallocatechin gallate (EGCG) on the physicochemical-rheological properties of silver carp surimi gel was investigated. The gel strength, texture, water-holding capacity (WHC), dynamic distribution of water, and rheological properties of surimi gels added with different levels (0, 0.02, 0.04, 0.06, 0.08, and 0.1%) of EGCG were measured. The results showed that with the increase of EGCG content, the gel strength, hardness, WHC, and immobilized water contents of surimi gels showed a trend of first increasing and then decreasing, and EGCG 0.02% and EGCG 0.04% showed better gel performance as compared with the control. EGCG 0.02% had the highest gel strength (406.62 g·cm), hardness (356.67 g), WHC (64.37%), and immobilized water contents (98.958%). The gel performance decreased significantly when the amounts of EGCG were higher than 0.06%. The viscosity, G\', and G″ of the rheological properties also showed the same trends. The chemical interaction of surimi gels, secondary structure of myofibrillar protein (MP), and molecular docking results of EGCG and silver carp myosin showed that EGCG mainly affected the structure and aggregation behavior of silver carp myosin through non-covalent interactions such as those of hydrogen bonds, hydrophobic interactions, and electrostatic interactions. The microstructures of EGCG 0.02% and EGCG 0.04% were compact and homogeneous, and had better gel formation ability. The lower concentrations of EGCG formed a large number of chemical interactions such as those of disulfide bonds and hydrophobic interactions inside the surimi gels by proper cross-linking with MP, and also increased the ordered β-sheet structure of MP, which facilitated the formation of the compact three-dimensional network gel.