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; star ter-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 ripe ning of the cheeses. Proteolysis was evaluated by the determination of diff erent nitrogen fractions, urea-PAGE, RP-HPLC and free amino acids analysis. Results were processed statistically. Results showed that in rennet-free and rennet- and starter-free cheeses, th e alpha (s1)-casein remained intact at the end of ripening. On the other ha nd, an intense proteolysis of alpha (s1) casein with the formation of the a lpha (s1)-I peptide was observed in control cheeses and in cheeses with dou ble dose of coagulant. Cheeses with half dose of coagulant showed a light f ormation of alpha (s1)-I peptide. It can be concluded that rennet is the most important enzyme in the ripenin g of Cremoso Argentino cheese. Secondary proteolysis was not intensive and the lactic acid starter is responsible only of a light proteolysis. beta ca sein was not cleaved during ripening.