Analysis of bovine caseins and primary hydrolysis products in cheese by capillary zone electrophoresis

Summary - Casein fractions from milk and various cheeses as weil as isolated casein standards were analysed by capillary electrophoresis under acidic conditions, Capillary electrophoresis was performed on a Waters Quanta 4000 apparatus with a hydrophilically coated or an untreated fused-silica capillary. The four major caseins in an acid precipitate from milk were weil separated. In addition, the various phosphorylation states of the asl- and the as2-caseins and sorne genetic variants of ~-casein were separated. The major casein hydrolysis products formed in cheese, para-x-casein, asl-ca~ein-I and y-caseins, were separated from their parent ca~ein and from most other major caseins. The linearity of the method with respect to injection time and case in concentration was acceptable. With improved repeatability of peak areas the method should be superior to urea-PAGE and an attractive alternative to high-pressure Iiquid chromatography (HPLC) methods for following casein proteolysis in dairy products.