ANALYSIS OF WHEY PROTEINS DURING RIPENING OF AFUEGAL-PITU CHEESE BY REVERSED-PHASE HPLC

Evolution of the whey proteins fractions and proteolysis indices from 12 batches of the artisan cheese Afuega'l Pitu variety were studied by reversed phase high performance liquid chromatography (RP-HPLC) over the ripening period. The correlation coefficients between the whey pro tein contents and ripening time were very low, indicating that the whe y protein content did not change as the cheese aged. However, soluble nitrogen content and the percentage of total nitrogen in the soluble f orm showed correlation coefficients higher than 0.9 with increasing ri pening time. Analysis of variance showed significant differences (p < 0.05) between dairies for most of the variables with the exception of beta-lactoglobulin A and bovine serum albumin. These variables were al so significantly different between the two manufacture zones. Converse ly, no significant differences (p < 0.05) were observed between the tw o varieties of cheese, red and white, for whey protein content or for proteolysis indices.