Medium and higher molecular weight volatile thiols in aged cheddar cheese and their relation to flavor

Attention has been given to expand our knowledge in respect to the role of sulfur compounds in the flavor of aged Cheddar cheese. A new method, based on the concentration of reduced thiol compounds and their analysis by a sulfur-specific GC detector shows the presence of 39 thiol compounds in the aged Cheddar cheeses. Of these 14 were tentatively identified by Kovat's indices and the presence of 4-mercapto-4-methyl pentan-2-one confirmed with a pure standard. These 14 thiol compounds possess an additional alcohol, aldehyde, or ketone functional group.; The results of this method were substantiated by other analyses (descriptive sensory analysis and electronic nose). Sensory analysis showed that there were four different sulfur descriptors (total sulfur, egg-like, match-like and catty) that differenced the eleven cheeses. Total sulfur and catty were correlated to age of the cheese and catty and match-like were also correlated. The electronic nose, using a mass spectrometer in NCI mode, gave similar differentiation patterns to the sensory and also suggest that 4-mercapto-4-methyl pentan-2-one was associated with the differentiation of the aroma.; The three analytical approaches all confirm the importance of sulfur compounds to the flavor of aged Cheddar cheese and all help support the significance of the poly functional thiols in Cheddar cheese flavor, especially the 4-mercapto-4-methyl pentan-2-one (catty) compound.; An additional 15 medium and higher molecular weight thiols were partially characterized by Kovat's Retention Indexes, and their molecular weights were estimated within a range of a few grams.