Volatile compounds associated with desirable flavour and off-flavour generation in ewe´s raw milk commercial cheeses

This study investigated relationships between the volatile profile and balanced flavour of high sensory quality ewe’s raw milk commercial cheeses, and those relations between certain volatile compounds and off-flavours in defective cheeses. Commercial cheeses were selected in the routine sensory quality control from 27 farmhouses. High sensory quality cheeses showed a particular desirable balanced flavour and volatile profile. However, an imbalanced composition of volatile compounds was found in off-flavour cheeses. Rancid off-flavour was mainly related to an excessive concentration of n-butanoic and n-hexanoic acids, and their corresponding ethyl esters, generated by strong lipolysis during ripening. Animal off-flavour was associated with the generation of 3-methylbutan-1-ol, 2-phenylethanol and 4-methylphenol originated by amino acid catabolism after intense proteolysis. Finally, acid off-flavour was related to an excessive abundance of acetic acid generated mainly by strong glycolysis at early stages of ripening.