Flavour and off-flavour compounds of Swiss Gruyère cheese. Identification of key odorants by quantitative instrumental and sensory studies

Potent odorants of a typical sample of Gruyère cheese and of a Gruyère exhibiting a potato-like off-flavour were quantified by isotope dilution analysis. The studies of sensory models revealed that 2-/3-methylbutanal, methional, dimethyltrisulphide phenylacetaldehyde, 2-ethyl-3,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, methanethiol, as well as acetic, propionic, butyric 3-methylbutyric and phenylacetic acids comprise the typical flavour of Gruyère cheese. The potato-like character of one sample showing an aroma defect, however, was mainly attributed to a too high concentration of methional.