湿法糖基化处理大豆11S蛋白后的表面活性变化

Changes in Surface Activity of Soybean 11S Protein Treated by Glycosylation by Means of Wet-Heating

为改善大豆11S蛋白的表面活性,从脱脂豆粕中提取大豆11S蛋白,采用湿热糖基化法将大豆11S蛋白分别与不同分子质量(4、10、70 ku)的葡聚糖在80℃下反应1、2、3、4、5 h,进行糖基化改性处理,研究糖基化改性产生的大豆11S蛋白-葡聚糖轭合物的表面活性变化。结果表明,糖基化可以改变大豆11S蛋白的结构,从而对其表面活性产生影响,低分子葡聚糖(4、10 ku)湿法糖基化反应有利于增加大豆11S蛋白在等电点附近的溶解性;湿法糖基化处理后轭合物的乳化稳定性、持水性、Zeta电位值普遍增加;乳化活性、持油性、表面疏水性普遍降低。此外,低分子质量葡聚糖与大豆11S蛋白糖基化反应程度更深,对表面活性改善效果更明显。

To improve the surface activity of soybean 11S protein,soybean 11S protein extracted from defatted soybean meal and dextran with different molecular weights(4,10,70 ku)were incubated at 80℃ for 1,2,3,4,5 h by means of wet-heating to fabricate conjugates.The surface activities of soybean 11S protein-dextran conjugates produced by glycosylation modification were studied.The results showed that the glycosylation could change the protein structure of soybean 11S protein to affect its surface activity.Soybean 11S protein glycosylated with low-molecular-weight dextran(4,10 ku),in general,showed an improvement of solubility at the isoelectric point,emulsifying stability,water holding capacity,and Zeta potential value,but a reduced emulsifying activity,oil holding capacity and surface hydrophobicity.In addition,the dextrans with 4 and 10 ku presented higher reactivity than dextran(70 ku)when glycosylated with the soybean 11S protein,reaping a better effect of improving surface activity.