Etude du rôle des micro-organismes et des enzymes au cours de la maturation des fromages. II. - Influence de la présure commerciale

Abstract

The role of rennet in cheese ripening was studied in an aseptic model curd [see DSA 38, 1057] free from microbial proteases. Casein breakdown was investigated by fractional precipitation, gel chromatography with or without dissociating solvents, and acrylamide agarose gel electrophoresis. Rennet alone released sufficient peptides (mainly of high mol. wt.) to give soluble N (pH 4.6) values similar to those for commercial cheese, e.g. Saint-Paulin. After 40 days' ripening, peptides of mol. wt. below 3000 represented only 5% of total N. Rennet acted mainly on alpha s1-casein, which had virtually disappeared from electropherograms after 20 days' ripening, whereas 2/3 of beta -casein was unaltered after 40 days' ripening, representing the major proportion of intact caseins