Proteolysis in Camembert cheese during ripening

dCamembert cheese is produced by ripening with Penicillium camemberti or P. caseicolum. Remarkable proteolysis by proteolytic enzymes proceeds during this short ripening period. The degradation of milk proteins in the cheese during ripening was monitored by nitrogen distribution, SDS-polyacrylamide gel electrophoresis (PAGE), urea-PAGE and peptide analysis. The increase of water soluble nitrogen was greatest at the final stage of ripening. alpha(S1)-Casein was degraded earlier than beta-casein. alpha(S1)-Casein was degraded at first by chymosin. As the amounts of mold protease in cheese increased, degradation products of alpha(S1)-casein and beta-casein increased markedly on 10 days and after. These changes proceeded from the surface to the center. Most kinds of free amino acids increased a little during the first 2 days of ripening. Further rapid increase of them was observed during the following 10 days of ripening. In the increased free amino acids, Glu, Ser and Pro were found in quantity. Therefore, these milk caseins in the cheese were presumed to be degraded to low molecular peptides and amino acids. These results showed that proteolysis in the cheese occurred in the whole at the initial stage, and then it proceeded from the surface to the center in the final stage.