氧化条件下没食子酸对猪肉肌原纤维蛋白结构及凝胶特性的影响

构建肌原纤维蛋白Fenton氧化体系（10μmol/L Fe Cl₃,100μmol/L V_C和1 mmol/L H₂O₂）,以没食子酸（10、50、100、150μmol/g蛋白）作为抗氧化剂添加到氧化体系中,通过测定蛋白质表面疏水性、色氨酸荧光强度、凝胶强度、保水性、白度、流变特性及微观结构,研究在氧化条件下,没食子酸的抗氧化效果及其对蛋白质结构和凝胶特性的影响。结果表明,随着没食子酸浓度的增加,蛋白质的表面疏水性逐渐增加,凝胶强度和保水性呈下降趋势,凝胶白度略有上升,其微观结构受到破坏;色氨酸荧光强度随没食子酸浓度的增加而增加,但在150μmol/g时略有降低;且较高浓度下（50、100、150μmol/g）,蛋白失去典型的流变特征。总的来说,低浓度没食子酸在起到抗氧化作用的同时,对肌原纤维蛋白结构及凝胶特性的影响较小,而较高浓度的没食子酸破坏了蛋白的凝胶结构。 

Effect of gallic acid on constructure and gel properties of pork myofibrillar protein under oxidation conditions

Fenton oxidation system( 10 μmol / L Fe Cl_3,100 μmol/L VCand 1 mmol / L H_2O_2) of myofibrillar protein was established and gallic acid( 10,50,100,150 μmol / g) was added as antioxidant. The surface hydrophobicity,tryptophan intensity,gel strength,water-holding capacity,whiteness,rheological properties and microstructure of myofibrillar protein were investigated to illuminate the antioxidant effect of gallic acid and its effect on protein structure and gel properties. With the increase of gallic acid concentration,surface hydrophobicity was increased gradually,gel strength and water-holding capacity were decreased,whiteness of gel was increased slightly and microstructure was destroyed. Tryptophan fluorescence intensity was increased with the increasing of gallic acid concentration,but showed slightly lower at 150 μmol / g. At higher concentrations( 50,100,150 μmol / g),the typical characteristics of rheological properties were lost. In conclusion,low concentrations of gallic acid showed antioxidant activity and had slight effect on the structure and gel properties,but high levels of gallic acid had damage effect on the protein gel properties.