Distribution and sensory impact of new oak wood-derived compounds in wines
Despite the numerous research studies carried out in recent years, the study of wine aroma remains of great interest due to its complexity. Wine maturation in oak barrels is described as an important step in the production of quality wines. In fact, oak wood develops several aromatic nuances through its toasting which can be released into the wine. A great deal of work has been performed in order to identify the wood-derived volatile compounds that contribute to wine aroma (e.g., whisky-lactone, maltol, eugenol, guaiacol, vanillin). However, these compounds only partially explain oak wood aroma and its contribution to wine richness and complexity. Recently, two new unsaturated aldehydes have been identified as being responsible for the “woody” character of oak wood (Quercus petraea): (2E,4E,6Z)-nonatrienal (1) reminiscent of puff pastry odor and trans-4,5-epoxy-(E)-2-decenal (2) reminiscent of metal odor. These compounds are quantified for the first time in wood, wines and spirits by using SPE extraction and optimized GC-MS NCI (NH3) separation and detection. Their olfactory detection thresholds are 16 ng/L (1) and 60 ng/L (2) in a model wine solution. We demonstrated that their distribution in oak wood samples was impacted by toasting treatments and was ranged from some ng/g to 85 ng/g for (1) and 210 ng/g for (2). Analysis of 66 wines revealed those highest levels of (1) (441.3 ng/L) and (2) (524.4 ng/L) were found in a red wine and a white wine, respectively. Moreover, at these levels, these aldehydes modify the balance of the fruity expression in both types of wine. A further study highlighted the role of fatty acids, principally linoleic and α-linolenic acids, as aroma precursors. Additional results concerning these precursors in oak wood and wine were also discussed. They provide new insights into the contribution of oak wood ageing to the complexity of wine aroma.
Issue: ICGWS 2023
1Univ. Bordeaux, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, F-33140 Villenave d’Ornon, France
2Bordeaux Sciences Agro, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, F-33170 Gradignan, France
3Tonnellerie Seguin Moreau, Merpins, France
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trans-4,5-epoxy-(E)-2-decenal, 2,4,6-nonatrienal, oak wood maturation, fruity aroma modulation, fatty acids