Wine aroma is one of the most important attributes for wine quality. To understand the volatile compounds responsible for wine aroma, wine is typically extracted with an organic solvent using liquid-liquid extraction (LLE), then analyzed by gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA) to determine the most important compounds. This protocol requires large quantities of organic solvent. The extracts also contain high levels of alcohols and acids that interfere with analysis. A simple Lichrolut-EN resin-based solid phase extraction was compared to traditional LLE to study the aroma compounds in Merlot wine. The extracts were passed through a solvent-assisted flavor evaporation device and analyzed by AEDA. In general, SPE was comparable to LLE in obtaining aroma extracts suitable for GC-O analysis, but it was faster and used much less organic solvent. SPE extract had higher flavor dilution values than LLE for esters and lactones but lower values for acids, alcohols, phenolics, and sulfides. AEDA detected ethyl 2-methylpropanoate, ethyl butanoate, ethyl 2-methylbutanoate, ethyl isovalerate, ethyl octanoate, isoamyl acetate, 2,3-methyl-1-butanol, b-damascenone, butanoic acid, 3-methylbutyric acid, hexanoic acid, vanillin, guaiacol, eugenol, 4-vinylphenol, 4-vinylguaiacol, 4-methylguaiacol, cis/trans-whisky lactone, γ-nonalactone, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, homofuraneol, sotolon, methional, 3-(methylthio)propanol, 3-isopropyl-2-methoxypyrazine, 3-isobutyl-2-methoxypyrazine, and 3-hydroxy-2-butanone as the most important odorants for Merlot wine.

Funding Support: Oregon Wine Research Institute, China Scholarship Council