Resumen de Gas chromatography coupled with mass spectrometry detection for the volatile profiling of vitis vinifera cv. Carménère wines

Ana María Domínguez, Eduardo Agosin

• The volatile metabolome of Vitis vinifera C. V. Carménère wines, a unique Chilean winegrape variety, was characterized in this work. After solvent extraction with dichloromethane (LLE) or head space solid phase microextraction (HS-SPME), the resulting volatile compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). Specific methods were carried out too for the determination of methoxypyrazines andthiols. Almost 150 compounds corresponding to aliphatic and aromatic alcohols, organic acids, acetate and ethyl esters, lactones, terpenes, norisoprenoids, pyrazines, thiols and phenolic compounds were found in these wines. Both extraction techniques were complementary; HS-SPME allowed to identify several important compounds that were not detected by liquid-liquid solvent extraction, in particular b-damascenone, nerolidol, citronellol, linalool, ethyl 2-methyl-butyrate and geranyl acetone. Several varietal volatile compounds with significant odorant properties were also identified: 3-mercaptohexyl acetate (3MHA), 3-mercaptohexan-l-ol (3MH), benzenemethanethiol (BM), 2-furanmethanethiol (2FM); and 2-isobutyl-3-methoxypyrazine (IBMP) while 2-isopropyl-3-methoxypyrazine (IPMP) and 4-mercapto-4-methylpentan-2-one (4MMP) were not detected. Twenty two of these compounds, including b-damascenone, several thiols, ethyl octanoate, 2-phenylethanol, and 2-isobutyl-3-methoxypyrazine, showed significant odor activities values (OAV), and were clearly related with the cooked fruits, berries-like and herbaceous notes characteristic of Carménère wines. Olfactometric techniques are underway to validate the sensory impact of these compounds.