SYMPOSIUM - PROTEOLYTIC-ENZYMES AND CHEESE RIPENING - PROTEOLYTIC-ENZYMES AND THEIR RELATION TO CHEESE RIPENING AND FLAVOR - AN OVERVIEW

Proteolytic events taking place during cheese ripening are described, and the characteristics of the various proteolytic systems involved are reviewed. Some emphasis is placed on the proteolytic enzymes from starter bacteria because these, in particular, have been subjects of recent and current research. In cheese, the concerted action of residual milk-clotting enzyme, indigenous milk proteinases, and starter proteinases provides suitable substrates for the starter peptidases, which ultimately generate small peptides and free amino acids. Deviations from such a delicately balanced process may lead to deviations from the desired cheese texture and flavor. A bitter flavor defect may develop in the ripening cheese when the degradation of slowly accumulating bitter peptides by suitable peptidases is inhibited. Cheese flavor is thought to be mainly generated by the further, nonproteolytic conversion of amino acids via enzymic and nonenzymic reactions.