Effect of Combining Single-Strain Cultures as Cheese Starter on Bitterness in Cheddar Cheese at Six Months of Age

Abstract

Summary Five strains of Streptococcus cremoris were used to investigate how bitterness in pasteurized-milk cheese was influenced by different combinations and proportions of paired strains in the starter. The combination of strains as starter influenced bitterness in cheese at six months of age as follows: (a) The intensity of bitterness decreased as the proportion of the nonbitter-cheese-producing strain in the starter increased; (b) the intensity of bitterness was less in cheese made with Strain ML 1 in the combination than with Strain E 8 , even though the intensities of bitterness were low in cheeses made with either ML 1 or E 8 alone; and (c) the combination of two bitter-cheese-producing strains yielded bitter cheese. The results showed that nonbitter cheese could be produced even if one strain produced bitter cheese when used alone as starter. Being able to use a bitter-cheese-producing strain as one of a pair of strains in a starter simplifies the problem of selecting strains for rotation in a phage-control program. The intensity of bitterness was higher in cheese where the average chain lengths of TCA-soluble peptides and amino acids were higher.