| Abstract
| - Toasting wood to be used in barrels for aging wine and brandy produces agreat number of volatileand odiferous compounds. Some of these have a “toasty caramel”aroma. Analysis by high-performance gas chromatography of toasted oak extracts, combined witholfactory detection, enabledvarious chromatographic peaks with these specific aromas to beisolated. These same odors weresimultaneously studied by heating glucose both with and withoutproline. Aromatic compounds ofinterest were identified thanks to a combination of gas chromatographyand both mass and infraredspectrometry. In addition to already-known substances such as2-hydroxy-3-methyl-2-cyclopenten-1-one (cyclotene) (1) and3-hydroxy-2-methyl-4H-pyran-4-one (maltol) (2),we identified, for the firsttime, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one(DDMP) (3),4-hydroxy-2,5-dimethyl-3(2H)-furan-3-one (furaneol) (4), and2,3-dihydro-5-hydroxy-6-methyl-4H-pyran-4-one(dihydromaltol) (5)as compounds which actively contribute to the “toasty caramel”aroma of heated oak. Their role inthe aroma of wines and spirits is thus well worth studying. Thesemolecules were absent from theglucose pyrolysis but were relatively plentiful after heating in thepresence of proline. Therefore,Maillard reactions were seen to be the cause of these substances in theheated oak wood. Keywords: Oak; thermal degradation; volatile compounds; “toasty” aroma;Maillard reactions
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