Validation of a reversed-phase high-performance liquid chromatographic method for the quantification of primary proteolysis during cheese maturation

A new fast and reliable reversed-phase high-performance liquid chromatographic method is proposed for quantifying all the major casein fractions during cheese proteolysis as an alternative to more complex methodologies. Excellent separation of the caseins, para-kappa-casein (rho-kappa-CN), alpha(s1)-casein (alpha(s1)-CN), alpha(s1)-I-casein (alpha(s1)-I-CN), alpha(s2)-casein (alpha(s2)-CN), and beta-casein (beta-CN) was achieved, in terms of linearity, reproducibility, repeatability, accuracy and certified standard recovery. Validation by quantification of semihard and Maasdam-style cheeses gave comparable results for rho-kappa-CN, beta-CN and alpha(s)-casein (alpha(s)-CN) to published data for both urea-polyacrylamide gel electrophoresis and capillary electrophoresis.