该文以不同pH值的Fenton氧化体系孵育24 h的牦牛肉肌原纤维蛋白（MP）形成的凝胶为研究对象，通过对其白度、持水性、质构等特性的研究，探究不同pH值下蛋白氧化对凝胶特性的影响，分析该条件下化学作用力、流变、微观结构的差异性变化。结果表明：不同pH值下随H2O2 浓度的增加，蛋白凝胶白度、持水、质构显著降低（P<0.05)。疏水相互作用力是维持凝胶的主要作用力，其次是二硫键、离子键和氢键，随着H2O2 浓度的增加，疏水作用力和二硫键显著上升，离子键和氢键显著下降（P<0.05）。pH值为5.0时氧化对凝胶特性影响最为明显，MP凝胶持水性最低，为77.20%，质构强度最差，仅有53.40 g，储能模量、蛋白分子间作用力最小，微观结构松散、无序。pH值为6.0时氧化对凝胶特性影响最弱，MP凝胶质构强度最大，为61.40 g，储能模量、分子间作用力最大，微观结构致密有序。为牦牛肉中蛋白氧化控制提供理论基础。

In this study, the gels formed by yak muscle myofibril protein (MP) incubated for 24 h in Fenton oxidation systems at different pH values were taken as the research objects. Through examining their characteristics such as whiteness, water retention and texture, the effects of protein oxidation on the gel propertiesat different pH values were explored. The differences in chemical force, rheology and microstructure under the conditions were analyzed. The results showed that the whiteness, water-holding capacity and texture of protein gel decreased significantly with an increase of H2O2 concentration at different pH values (P＜0.05). The hydrophobic interaction force was the main force to maintain the protein gel, followed by disulfide bond, ionic bond and hydrogen bond. With the increase of H2O2 concentration, the hydrophobic interaction force and disulfide bond increase significantly, whilst the ionic bond and hydrogen bond decrease significantly (P＜0.05). When the pH value was 5.0, oxidation had the most obvious effect on the gel characteristics. MP gel had the lowest water holding capacity (77.20%), the worst texture strength (only 53.40 g), the smallest storage modulus, and the weakest intermolecular force between proteins, leading to a loose and disordered microstructure. When pH value was 6.0, oxidation had the weakest effect on gel characteristics. MP gel had the highest texture strength (61.40 g), the largest storage modulus and intermolecular force, with the microstructure being compact and orderly. This study provides a theoretical basis for the control of protein oxidation in yak meat.

中央高校基本科研业务费项目（2021XJTD02）