Monitoring proteolysis during ripening of full-fat and lowfat cheddar cheeses by reverse-phase HPLC

Proteolysis during ripening of full-fat and low-fat Cheddar cheese was investigated by applying reverse-phase HPLC to the pH 4.6 water-soluble N fraction of cheese. The separated N compounds were divided into four MW ranges. The number of separated peaks and the amount of N compounds separated in each of the MW ranges increased with ripening time. Significant within-cheese, within-variety, and between-varieties differences in the amounts and proportions of N compounds with different MW were observed as related to ripening time. Reverse phase HPLC of the pH 4.6 water-soluble N fraction of cheese can provide detailed quantitative information on proteolytic activities during ripening.