Analysis of wines from different grape varieties marked by sometimes intense aromatic nuances of fresh mushroom was performed by GC coupled with olfactometry.
This analysis has led to the identification of several odoriferous zones, which were recalling a fresh mushroom odour. 2 trace compounds responsible for these odoriferous zones, 1-nonen-3-one and 1-octen-3-one, have been identified and their content has been determined by using either a multidimensional GC technique coupled to olfactometry and MS detection (in the case of 1-nonen-3-one) or the preparation of the derivative with O-2,3,4,5,6-pentafluorobenzylhydroxylamine hydrochloride in the presence of the deuterated form, as the internal standard (in the case of 1-octen-3-one), then GC coupled to MS detection.
The assays allowed the quantification of these compounds at concn. levels sometimes well above their detection and recognition olfactory threshold. It was shown that adding nitrogen compounds to the altered wines, such as an amino acid (glycine) or a tripeptide (glutathione), led to lower concn. of 1-octen-3-one in wines and diminished the smell of fresh mushrooms.
The study of the reaction in a model medium, whose composition is close to wine, by LC coupled to MS demonstrated the formation of adducts between 1-octen-3-one and glycine, and 1-octen-3-one and glutathione characterized by NMR
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