Changes in soluble nitrogenous compounds, caseins and free amino acids during ripening of artisanal prato cheese; a Brazilian semi-hard cows variety

Proteolytic changes, during ripening (1–60 days) of 12 batches of artisanal Prato cheese, a Brazilian semihard cows’milk variety, were evaluated by determining the soluble nitrogenous compounds, caseins and their degradation products and free amino acids. Levels of pH 4.4-soluble nitrogen (pH 4.4-SN) and 12% TCA-soluble N, expressed as% TN, at the end of ripening were 21.4 and 12.5, respectively.% Aminoacid nitrogen/TN increased significantly (P<0.05) during ripening to final values of 4.32. The degradation patterns of αs1- and β-caseins were similar in all cheese batches and αs1-casein was hydrolysed more extensively than β-casein during ripening. The total content of free amino acids increased aproximately 8 times throughout ripening with average final values of 2454 mg/100 g total solids. γ-Amino butyric acid, leucine, lysine, glutamic acid, tryptophan and phenylalanine were the most abundant free amino acids in all batches studied, representing of 62% of total free amino acids.