CHEMICAL AND MICROBIOLOGICAL CHANGES IN ROQUEFORT STYLE CHEESE DURING RIPENING

Changes in the chemical composition and microbial contents of locally produced Roquefort style cheese were studied over a period of 3 months of ripening. Total nitrogen, soluble nitrogen, non-protein nitrogen, tyrosine, tryptophan, total volatile fatty acids all increased during the ripening while only moisture content decreased. On the other hand, while Penicillium roqueforti was over-growing in the cheese with progressive ripening, the majority of specific bacterial counts tended to decrease up to the end of ripening. Bacillus cereus and the non-enterotoxin producer Staphylococcuc aureus were detected in the fresh cheese, and they survived the whole period of ripening. While all of the cheese samples were free of PR toxin, 16.6% of P,roqueforti isolates were found to produce the material in artificial culture. © 1990, Taylor & Francis Group, LLC. All rights reserved.