This study investigated the effects of different concentrations (0, 5, 10, 20, 50, and 100 μmol/g protein) of tea polyphenols (TP) on the oxidative modification and the physicochemical, structural, and gelling properties of myofibrillar protein (MP) from grass carp (Ctenopharyngodon idellus) oxidized by a hydroxyl radical-generating system. The results showed that low concentrations (5 and 10 μmol/g protein) of TP could effectively inhibit the formation of carbonyl groups and dityrosine, the loss of sulfhydryl groups and α-helix conformation, and the change of the tertiary structure of MP caused by hydroxyl radicals. Moreover, the presence of TP in all concentrations decreased the surface hydrophobicity of MP. TP at 10 μmol/g protein had better effects on preventing the oxidation-induced cross-linking and aggregation of myosin heavy chain (MHC) and actin of MP, keeping the stability of MP solutions with lower turbiscan stability index (TSI) values, and improving gelling properties characterized by higher hardness and gel strength of MP gels. By contrast, excessive presence of TP (20, 50, and 100 μmol/g protein) showed pro-oxidative effects on oxidatively stressed MP, which was detrimental to the MP and contributed to the denaturation and irregular aggregation of MP, the loss of MP solution stability, and lower gelling capacity with poor texture and gel strength. The concentration-dependent effects of TP on MP depended on the extent of MP oxidative modification and MP-TP interactions, indicating that a proper amount of TP has the potential to protect MP from oxidation and to enhance the gelling capacity of surimi during processing.

这项研究调查了茶多酚（TP）不同浓度（0、5、10、20、50和100μmol/ g蛋白质）对肌原纤维蛋白（MP）的氧化修饰以及理化，结构和胶凝特性的影响）从草鱼（Ctenopharyngodon idellus））被产生羟基自由基的系统氧化。结果表明，低浓度的TP（5和10μmol/ g蛋白）可以有效抑制羰基和二氢酪氨酸的形成，巯基的丢失和α-螺旋构象以及MP引起的三级结构的变化。羟基自由基。此外，所有浓度的TP的存在都会降低MP的表面疏水性。TP在10μmol/ g蛋白下对预防肌球蛋白重链（MHC）和MP的肌动蛋白的氧化诱导的交联和聚集具有更好的效果，同时保持MP溶液的稳定性和较低的Turbiscan稳定性指数（TSI）值，并且改善胶凝特性，其特征是MP凝胶具有更高的硬度和凝胶强度。相比之下，TP过多（20、50，和100μmol/ g蛋白）对氧化应激的MP表现出促氧化作用，这对MP有害，并导致MP的变性和不规则聚集，MP溶液稳定性的损失以及较低的胶凝能力，且质地和凝胶较差强度。TP对MP的浓度依赖性效应取决于M​​P的氧化修饰程度和MP-TP相互作用，这表明适量的TP有潜力保护MP免受氧化并在加工过程中增强鱼糜的胶凝能力。