Use of Protein Dye‐binding Values as Indicators of the “Chemical Age” of Conventionally Made Cheddar Cheese and Hydrolyzed‐lactose Cheddar Cheese

A dye‐binding method using amido black dye was developed for determining the “chemical age” of Cheddar cheese. Samples of cheese from two manufacturing processes were analyzed during 8 months of ripening: conventional cheese manufacture and a hydro‐lyzed‐lactose process that results in a more rapidly ripening cheese. Free amino acid analyses were also made and those data compared with dye‐binding values (DBVs). The DBVs correlated to the free amino acid values by 0.85 and 0.84 in the conventional and hydro‐lyzed‐lactose processes, respectively. A quadratic model was established between the DBVs and the free amino acid data. In the different cheese samples analyzed this resulted in a multiple correlation coefficient of 0.82 for the following regression equation: μg = 1374–130.4 (DBV) + 2.83 (DBV) 2 . The standard error of estimate of this method was 2.4 mg/g of cheese.