FREE AND TOTAL AMINO-ACIDS IN THE NONPROTEIN FRACTION OF AN ARTISAN BLUE CHEESE DURING RIPENING

Changes in the free amino acid content and total amino acid content of the fraction soluble in 5% phosphotungstic acid from three batches of blue cheeses were studied by HPLC over the ripening period. The correlation coefficients between the free and total amino acids and ripening time were positive and higher than 0.85 for most amino acids. Non-protein amino acids showed the lowest correlations with ripening. Principal component analysis performed on the data showed ripening time to be the main cause of variation between the samples analyzed, explaining 60% of the variance; differences between batches were the second most important source of variation (15%). The ripening stage can be approximately estimated from the concentration of certain amino acids.