CONTRIBUTION OF STARTER LACTOCOCCI AND NONSTARTER LACTOBACILLI TO PROTEOLYSIS IN CHEDDAR CHEESE WITH A CONTROLLED MICROFLORA

Cheddar cheeses were manufactured under controlled microbiological con ditions to study the relative contribution of starter and non-starter bacteria to cheese ripening. In each of two trials, four cheeses were manufactured with or without a starter culture (starter-free cheeses w ere chemically acidified using glucono-delta-lactone). Adjunct culture s of mesophilic lactobacilli were added to one chemically-acidified an d one starter cheese. Assessment of proteolysis showed a major contrib ution by the starter in comparison to the non-starter bacteria to the formation of free amino acids and, to a lesser extent, water-soluble n itrogen. Reversed phase-HPLC of ethanol-soluble and -insoluble fractio ns of the water-soluble extracts detected some peptides (produced by l actobacilli) which were present in profiles of the starter-free cheese containing the adjunct but were not present in its corresponding cont rol.