Influence of milk-clotting enzyme in proteolysis during ripening of Cremoso Argentino cheese

The influence of milk-clotting enzyme on the ripening of Cremoso Argentino cheese, a typical Argentinean soft cheese, was studied. Experimental cheeses were made in a laboratory scale vat. Rennet free; starter-free, rennet-free cheeses; and cheeses with half and double the normal dose of rennet were prepared. Normal cheeses were used as the control. Physicochemical and microbiological analyses were performed during the ripening of the cheeses. Proteolysis was evaluated by the determination of different nitrogen fractions, urea-PAGE, RP-HPLC and free amino acids analysis. Results were processed statistically. Results showed that in rennet-free and rennet- and starterfree cheeses, the α s1 -casein remained intact at the end of ripening. On the other hand, an intense proteolysis of α s1 casein with the formation of the α s1 -1 peptide was observed in control cheeses and in cheeses with double dose of coagulant. Cheeses with half dose of coagulant showed a light formation of α s1 -1 peptide. It can be concluded that rennet is the most important enzyme in the ripening of Cremoso Argentino cheese. Secondary proteolysis was not intensive and the lactic acid starter is responsible only of a light proteolysis. β casein was not cleaved during ripening. Cette etude evalue l'influence de l'enzyme de coagulation sur l'affinage de fromage Cremoso Argentino, fromage a pâte molle typique d'Argentine. Deux types de fromages sont produits: le premier est produit sans presure et le second avec des doses de coagulant variees. Des analyses physicochimiques et microbiologiques sont effectuees pendant l'affinage du fromage et l'influence des bacteries lactiques et des enzymes laitieres endogenes est evaluee.