Identification of key-odorants in Sauternes Wines

The aim of the present work was to investigate Sauternes wines aromas. The flavor profiles of two wines (vintages 2002 and 2003) were investigated. Key-odorants have been determined by AEDA applied to Amberlite XAD-2 resin extracts. Various complementary techniques were used to identify the compounds (pHMB extraction, chemical synthesis of non-commercial standards, co-injections on two capillary columns, odor description at the sniffing port, GC-MS and GC-PFPD). Among key-odorants, varietal aromas (α-terpineol, linalool) and fermentation alcohols (3-methylbutanol, β-phenylethanol) and esters (ethyl butyrate, ethyl isovalerate, ethyl hexanoate) are relevant. Maturation in oak barrels provides changes in the aroma profile. Guaiacol, eugenol, vanillin, δ-nonalactone and cis-whiskylactone have a FD value ≥27 after maturation. Unreduced carbonyles such as trans-2-nonenal and β-damascenone can also be issued from oak. Polyfunctional thiols emerge as the most interesting odorants. Sotolon, previously described as characteristic of noble rot and indicator of wine oxidation, is underestimated in our XAD-2 extract. A specific extraction procedure has been therefore optimized.