阿魏酸存在下酪蛋白的酶促交联与一些性质变化

Oxidative cross-linking of casein by peroxidase in the presence of ferulic acid and impacts on some selected properties

在pH值为9.5,阿魏酸存在和37℃的条件下,利用辣根过氧化物酶(EC1.11.1.7)和过氧化氢对酪蛋白进行氧化交联,并用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳和紫外吸收分析确认交联作用。在蛋白质质量分数为0.04%时,交联酪蛋白的乳化活性指数、乳化稳定性分别比酪蛋白提高25.2%和7.0%。利用葡萄糖酸–δ–内酯制备酪蛋白和交联酪蛋白的酸化凝胶,扫描电子显微镜观察可以看出交联酪蛋白凝胶的微观结构中空穴减少,形成了更为致密的结构。

Horseradish peroxidase （EC 1.11.1.7） and peroxide hydrogen was used to oxidative cross-link casein in presence of H202 and ferulic acid at 37 qC and pH =9.5. Cross-linking of casein occurred was first demonstrated by SDS-PAGE and spectroscopic analysis. Cross- linked casein was then prepared and used to analyze its emulsifying activity index, emulsifying stability index and rnicrostructure of acidified gel. The emulsifying activity index and emulsifying stability index of cross-linked casein at concentration of proteins of 0.04% （w/w） were enhanced about 25.2% and 7% compared to that of casein at same concentration of proteins, respectively. The gel microstructure of cross-linked casein prepared by acidification of glucono-δ-lactone was observed by scanning electron microscopy as more compact and uniform structure.