毛细管电泳检测奶粉中添加的大豆分离蛋白

采用毛细管电泳方法对乳蛋白和大豆分离蛋白进行检测。选择聚丙烯酰胺涂层毛细管,在紫外检测波长214 nm、分离电压25 kV条件下测出五种乳蛋白在不同线性范围内的线性相关系数均大于0.998,各乳蛋白的迁移时间和峰面积的相对标准偏差(RSD)分别小于0.34%和4.50%,奶粉样品加标回收率范围为88.07%~102%;通过对比大豆7S和11S组分、大豆分离蛋白及乳蛋白的电泳图谱,定性确定出大豆分离蛋白8个特征峰,各特征峰的迁移时间和峰面积的RSD分别小于0.36%和4.87%,方法重现性较好。建立了奶粉中添加大豆分离蛋白的半定量检测方法。

Detection of Added Soy Protein Isolate in Milk Powder by Capillary Electrophoresis

This paper described a method for the determination of lactoprotein and soy protein isolate by capillary electrophoresis(CE).CE Separation was performed by using a polyacrylamide coated capillary with running voltage of 25 kV and UV detection at 214 nm.The linear correlation coefficient of 5 lactoprotein in different linear ranges were above 0.998,the RSDs of migration time and peak area for the proteins were less than 0.34% and 4.50% respectively,and the recoveries for the spiked milk powder sample were in the range of 88.07%~102%.Eight characteristic peaks of the soy protein have been identified with the RSDs of migration time and peak area less than 0.36% and 4.87%.The method had good reproducibility and was used for the semiquantitative detection of soy protein isolate in milk powder.