微波-超声波协同影响菜籽蛋白糖基化改性

Synergistic Effect of Simultaneous Microwave and Ultrasonic Treatment on Glycosylation of Rapeseed Protein

采用微波-超声波协同作用强化菜籽蛋白的糖基化改性,并对所得糖基化产物进行了功能性质和分子结构的对比分析。结果表明,当改性条件为微波功率500 W、超声波功率300 W、协同作用时间7 min时,菜籽蛋白的接枝度可达67.1%,显著高于湿热法和微波法制备的糖基化产物,有效提高了蛋白质糖基化反应的效率;协同作用可显著改善所得糖基化产物的溶解性、乳化活性、起泡能力、泡沫稳定性,分别提高至55.7%、13.9 m^2/g、50.0%和80.0%;糖基化产物的表面疏水性和圆二色谱结果分析表明,微波和超声波处理使得菜籽蛋白的分子展开,表面疏水性和分子柔性增加,从而促进了糖基化反应的进行,改善了蛋白质糖基化产物的功能特性。

The microwave-ultrasonic synergism(MUS)was applied in the glycosylation of rapeseed protein(RP)and the functional properties and molecular structure of RP-dextran conjugates were investigated.The results indicated that the grafting degree of RP was up to67.1%under the following reaction conditions:microwave power500W,ultrasonic power300W,and treatment time7min,which was even higher than that obtained by wet heating and microwave methods.Therefore,the combined treatment could significantly increase the efficiency of glycosylation reaction.Compared with rapeseed protein and the RP-dextran conjugates prepared by other methods,the solubility,emulsifying activity,foaming capacity,and foam stability of the RP-dextran conjugates prepared by MUS were significantly improved to55.7%,13.9m2/g,50.0%and80.0%,respectively.The results of surface hydrophobicity and circular dichroism(CD)spectroscopy indicated that combined microwave and ultrasonic treatment led to protein unfolding and increased the molecular flexibility of RP,thereby promoting the glycosylation reaction of RP and improving the functional properties of RP-dextran conjugates.