Effect of Strain of Starter Culture and of Manufacturing Procedure on Bitterness and Protein Breakdown in Cheddar Cheese

Abstract

Summary Eleven strains of Streptococcus cremoris were examined for their effect on bitterness in Cheddar cheese at six months of age. Four strains produced non-bitter cheese. The other seven strains produced bitter cheese, the intensity varying with the strain. According to nitrogen analyses of the cheese, strains producing bitter cheese hydrolyzed bitter-tasting peptides less extensively. The relation between bitterness and pH of cheese was studied by producing sweet and acid cheese with each strain, in addition to normal cheese. For each of the seven strains producing bitter cheese, bitterness in sweet cheese was less intense than in normal cheese, although sweet cheeses were often bitter. This experiment indicates that the selection of suitable strains for starter would control bitterness more satisfactorily than raising the pH of cheese. The results reconcile apparent anomalies between bitterness related to low pH and bitterness in cheese with a high pH. Strains were associated with significant differences in pH of cheese made by the same manufacturing procedure; these differences were unrelated to the intensity of bitterness. When the manufacturing procedure was changed to give cheese with a lower pH, the cheeses at six months of age generally contained greater amounts of acid-soluble, TCA-soluble and amino nitrogen. Differences in TCA-soluble nitrogen and in amino nitrogen were associated with the different strains.