Study on milk proteins in milk and milk products by capillary electrophoresis

The contents of milk protein were determined by capillary electrophoresis in raw milk,fresh milk in market,pasteurized milk from different plants,ultra-high temperature(UHT)milk from different plants and fields,sterilized flavor milk,lactic acid beverage,reconstituted milk,sour milk and milk powder.The proteins of α-La,β-Lg,α-CN,β-CN and k-CN were separated and analyzed by using polyvinyl alcohol coated capillary column and citric acid buffer solution with running voltage of 20kV and UV detection at 214nm.The results showed that the contents of five proteins decreased systematically in raw milk(fresh milk,pasteurized milk),UHT milk,sour milk,sterilized flavor milk,lactic acid beverage and reconstituted milk.And the contents of proteins in UHT milk decreased with the increase of their shelf life,the contents of proteins was changed with appropriate population.The contents of proteins in milk and milk products were related with their existing form,producing area and processing technology.