CAPILLARY ISOTACHOPHORETIC MEASUREMENT OF LOWER MOLECULAR-WEIGHT PEPTIDES AND BIOCHEMICAL-CHANGES DURING RIPENING OF CAMEMBERT CHEESE

Proteolysis in Camembert cheese was evaluated over a 4-week period of ripening. The proportion of various nitrogenous compounds increased during ripening. The Dowex-50 X-16 fraction and the non-adsorbed fraction contained more nitrogen than the other fractions. The nitrogen of the X-16 fraction showed a gradual increase in LMWP with progress of ripening. The X-16 fraction contained free amino acids, di- and tripeptides. An attempt was made to evaluate the proteolysis of LMWP in Camembert cheese by using a computer simulation system of capillary isotachophoresis (IP). By comparing the simulated R(E) values of IP with the observed qualitative index values of LMWP and amino acids, quantitative results were obtained. The step zones for 4 week ripened cheese calculated from the isotachopherogram were higher than in young cheese. The quantity of the compounds of R(E) 2.91, 4.00 and 4.46 in the X-16 fraction tended to increase during ripening of cheese. These compounds were glycyl-glycine dipeptide, leucine-leucine dipeptide and leucine, respectively. The quantity of the compounds of R(E) Of the X-8 fraction decreased during ripening, and the compounds corresponded to oligopeptides.