没食子酸抑制猪肉肌原纤维蛋白氧化及其与蛋白的交联作用

The Inhibition Effect of Gallic Acid on Oxidation of Pork Myofibrillar Proteins and the Crosslinking Interaction between Gallic Acid and Proteins

构建肌原纤维蛋白Fenton氧化体系(10μmol/L FeCl3,100μmol/L VC和1 mmol/L H2O2),并以没食子酸(10,50,100,150μmol/g蛋白)作为抗氧化剂添加到该体系中,通过测定蛋白质羰基、巯基、二级结构、溶解度、电泳(SDS-PAGE)和粒度,研究没食子酸的抗氧化效果及其在氧化条件下与肌原纤维蛋白的交联作用。结果表明,加入没食子酸后,与氧化的对照组相比,羰基、巯基和溶解度逐渐降低;粒度逐渐增加;二级结构中α-螺旋含量增加,β-折叠、β-转角以及无规则卷曲含量降低;肌球蛋白重链(MHC)强度增加,随着没食子酸浓度增加,MHC和肌动蛋几乎没有损失,且没食子酸与蛋白之间的交联是可被还原的。没食子酸具有一定的抑制蛋白氧化的效果,同时,没食子酸也会与肌原纤维蛋白发生交联反应,从而对其抗氧化活性和蛋白结构产生影响。

Fenton oxidation system(10 μmol/L FeCl3, 100 μmol/L VC and 1 mmol/L H2 O2) of myofibrillar protein was established. The gallic acid(10, 50, 100, 150 μmol/g protein) was used as antioxidants and added in the system.The carbonyl content, sulphydryl content, secondary structure, solubility, SDS-PAGE and particle size of myofibrillar protein were determined to investigate the inhibition effect of gallic acid on oxidation of pork myofibrillar proteins and the crosslinking interaction between gallic acid and proteins. Compared with the oxidized control group, the addition of gallic acid decreased the carbonyl content, sulphydryl content and solubility. The particle size increased gradually. The α-helical content increased, β-sheet, β-turns and unordered content decreased. The intensity of myosin heavy chain(MHC)increased. With the increase concentrations of gallic acid, the intensity of MHC and actin almost showed no change. The crosslinking interaction between gallic acid and proteins were reducible. In conclusion, gallic acid inhibited protein oxidation and cross linked with myofibrillar protein, thus affected the antioxidant activity of gallic acid and protein structure.