考马斯亮蓝法检测不同乳中乳清蛋白含量

目的建立考马斯亮蓝法(coomassie brilliant blue method, CCB)检测乳品中蛋白质的方法,并对几种常见乳中总蛋白质含量及乳清蛋白含量进行检测比较。方法用考马斯亮蓝G-250显色,以牛血清蛋白为对照品,采用可见分光光度法在检测波长595nm处测定各种乳中蛋白质的含量。结果该方法在0.005～0.1 mg/mL范围内与吸光度呈现良好的线性关系(r=0.9995),回收率为99.45%、相对标准偏差(relative standard deviation,RSD)为2.03%;不同种类乳中蛋白质含量存在差别,乳清蛋白占比也有很大的不同。结论考马斯亮蓝法检测蛋白,显色灵敏,具有简便,快捷,成本低等特点。各种乳蛋白检测比较中,马乳的乳清蛋白占比最接近母乳,这为马乳的进一步开发提供了新的理论基础。

Determination of whey protein content in different kinds of milk by coomassie brilliant blue method

Objective To establish a method for determination of protein in dairy products by coomassie brilliant blue method (CCB), and to compare the total protein content and whey protein content of several common milks. Methods Coomassie brilliant blue G-250 was used for color development, and bovine serum albumin was used as a reference. The content of protein in various milk was determined by visible spectrophotometry at the detection wavelength of 595 nm. Results The method showed a good linear relationship with absorbance in the range of 0.005-0.1 mg/mL (r=0.9995), the recovery rate was 99.45%, and the relative standard deviation (RSD) was 2.03%. There were differences in the protein content of different types of milk, and the proportion of whey protein was also very different. Conclusion The coomassie brilliant blue method is sensitive to color, which is simple, fast and low cost. In the comparison of various milk protein tests, the proportion of whey protein in horse milk is the closest to breast milk, which provides a new theoretical basis for the further development of horse milk.