| In recent years, raw milk adulteration is common in China. It′s found that some illegal manufactures adulterate some cheap non-lactoprotein and non-protein nitrogen in raw milk in order to obtain high profits and increase protein content, reduce cost. Not only to deceive consumers, or to even hazardous their health. In order to prevent such phenomeno, rapid detection methods are needed to detect milk proteins and audlteration of various raw milk situation. This paper aimed at studying on detecting milk proteins and establish fingerprint of milk proteins by Capillary Electrophoresis.This study was mainly conducted in four aspects. Firstly, selection a suitable method to separate and determine bovine milk proteins by comparing capillary (uncoated) zone electrophoresis and capillary (coated) zone electrophoresis. Secondly, applying the selected method of capillary electrophoresis to establish fingerprint of milk proteins. The better method of electrophoresis condition was optimized. Using standard sample, acurate qualitative and quantitative analysis for five protein in milk. Evaluating the similarity of fingerprints though the content similarity and index F and relative index Fr of chromatographic fingerprints. Thirdly, using the established capillary electrophoresis fingerprint to detect non-lactoprotein and non-protein nitrogen in raw milk. Finally, selection the suitable method to detect the distribution of protein in milk mixtrue and qualitative and quantitative analysis for milk adulartion.The results were as follows:1.The experiment proved that the two capillary zone electrophoresis methods, comparing with separation conditions, separation effect, quantitative characteristics and methodological study, Polyacrylamide coated capillary zone electrophoresis was better than the others. The electrophoresis condition of LPA coated capillary zone electrophoresis was optimized.2.Application of coated capillary zone electrophoresis method analysis of 10 raw milk origin of the Holstein cow milk protein, identified 10 peaks of milk protein. It can be used for qualitative identification. Good reproducibility, stability and recovery of the method meet the quantitative test results. With compare to raw milk fingerprints from different places, fingerprints similarity and content similarity were good. In addition, using index F and relative index Fr of chromatographic fingerprints to evaluate the merits of fingerprints. It can establish Fingerprint of raw milk protein from the above results.3.Using the established fingerprint of milk proteins analysis milk adulteration. According to the imitated adulteration by adding non-protein nitrogen and non-lactoprotein, we could qualitatively determine the raw milk adulteration. 4.Application of coated capillary zone electrophoresis method detect mixed milk with added goat milk.By comparing chromatograms from different species of milk through capillary zone electrophoresis method, to differentiate the two kinds of milk and find out the characteristics of casein. It was found that the ration of different casein peak area was good linear with different percentage of mixed milk. It can be used as quantitative detection of mixed milk indicators.The subject analysis milk proteins by capillary electrophoresis. The optimum conditions for the electrophoresis separation: separation voltage 25KV, pH=3.0, 25℃column, UV detection at 214nm. The correlation coefficients of five standard proteins concentrations were above 0.9986. the capillary electrophoresis fingerprints(CEFP)of milk proteins were established. the fingerprint congruence coefficients of 8 electropherograms in 10 were above 0.950. The method had a very good separation, defined some caseins as the qualitative detection of casein. It was found that the ration of different casein peak area was good linear with different percentage of mixed milk. Its congruence coefficients was above 0.997. It can be used as Quantitative detection of mixed-milk indicators.
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