Establishment And Application Of Milk Protein Fingerprints Based On Gel Filtration Chromatography

More and more adulated milk appears in recent years, some unscrupulous merchantsadulterated raw milk to reap fabulous profits. The action is not only reduce the nutritive valueof milk, but even be harmful to the consumers. Therefore, a rapid method to differentiate andassess quality of milk and adulterated milk is particularly important. This paper aimed atstudying on detecting milk proteins and establish fingerprint of milk proteins by Gel filtrationchromatography.The results were as follows:(1)GFC analysis was performed by an AKTA protein purification system. Data wereacquired and processed by the unicorn workstation. GFC analysis was performed on asuperdexTM7510/300GL column (10×300mm) with0.2mol·L-1NaH2PO4(pH7.0) asmobile phase. The flow rate was0.5mL·min-1. The wavelength of detecter was set at280nm.(2)Application of GFC method analysis of10raw milk origins of Xi’an, Baoji, Xianyangand Yangling, identified5satisfactorily-resolved characteristic peaks of milk protein. It canbe used for qualitative identification. Good reproducibility, stability and precision. Withcompare to raw milk fingerprints from different places, fingerprints similarities were above0.90, in9were above0.950.(3)The established fingerprint of milk proteins was used anglicizing milk adulteration.Comparing chromatograms from different species of adulated milk through peak time, height,area and mixed peaks, to differentiate the adulterant of soybeans, peanuts, soybean proteinpowder, gluten flour, hydrolyzed protein powder and melamine in raw milk.(4)Six types of milk samples were differentiated by GFC fingerprints combined withPCA. The variance contribution of two component parts was89.53%. The peanuts samplesare separated from the milk simples on PC1, the gluten flour samples were also separated onPC1. The soybeans samples, soybean protein powder, hydrolyzed protein powder samples andmelamine samples are separated from milk on PC2.