超声辅助糖基化反应改善蚕蛹蛋白乳化性的研究

Study on Improving the Emulsification of Silkworm Pupa Protein by Ultrasonic-Assisted Glycosylation

为提高蚕蛹蛋白的乳化稳定性,利用超声辅助低聚异麦芽糖接枝改性蚕蛹蛋白。在研究超声功率、超声时间、pH等因素对蚕蛹蛋白乳化性影响的基础上,利用Box-Behnken试验优化改性条件,并通过荧光光谱、紫外光谱和扫描电子显微镜研究蚕蛹蛋白改性前后的结构变化。结果表明,超声辅助低聚异麦芽糖接枝改性蚕蛹蛋白的最佳条件为:超声功率580 W,超声时间2 min,蚕蛹蛋白与低聚异麦芽糖的质量比1∶2.94,pH 8.10。在此条件下,改性后蚕蛹蛋白的乳化稳定性指数为44.84 min,比未改性蚕蛹蛋白提高了200.20%;改性后蚕蛹蛋白的分子结构发生了明显变化,其表面疏水性显著降低,冻干后的蚕蛹蛋白颗粒也变得多孔和疏松。

To improve the emulsification stability of silkworm pupa protein,ultrasonic-assisted isomaltose oligosaccharide grafting was used to modify silkworm pupa protein.On the basis of studying the effects of ultrasonic power,ultrasonic time,pH and other factors on the emulsification of silkworm pupa protein,Box-Behnken was used to optimize the modification conditions.The structural changes of silkworm pupa protein before and after modification were studied by fluorescence spectroscopy,ultraviolet spectroscopy and scanning electron microscopy.The results showed that the optimal conditions for the ultrasonic-assisted glycosylation modification were as the following:ultrasonic power 580 W,ultrasonic time 2 min,mass ratio of protein and isomaltose oligosaccharide 1∶2.94,and pH 8.10.Under these conditions,the emulsification stability index of the modified silkworm pupa protein was 44.84 min,which was 200.20%higher than that of the unmodified silkworm pupa protein.After modification,the molecular structure of silkworm pupa protein changed obviously.Its surface hydrophobicity reduced significantly,and the lyophilized silkworm pupa protein particles became porous and loose.