Various molecular compounds are responsible for the complex mixture of fragrances that give wine its aroma. In particular, the ‘cooked fruit’ aroma found in red wines from hot and/or dry vintages or from the vinification of late harvested grapes has been intensively investigated in recent years. Lactones and especially γ-nonalactone were found to be responsible for the ‘cooked fruit’ aroma and are able to modulate its intensity. 1,2 This project aimed to study γ-nonalactone formation in order to better predict the intensity of the ‘cooked fruit’ character of wines in relation to the grape maturity. Thanks to our previous work, one precursor of γ-nonalactone has already been identified and quantified in must and wine: the 4-oxononanoic acid. 3 This work is devoted to study alternative γ-nonalactone formation pathways, especially from the products of C18 unsaturated fatty acid peroxidation. 4 That why 4-hydroxy-2-nonenal was suggested as a potential γ-nonalactone precursor. For its quantification in must and wine, the SPE-GC-MS analysis was developed, validated and applied to assaying this compound in must and wine from Bordeaux area. Then, the strereoselective biotransformation of 4-hydroxy-2-nonenal into R/S-γ-nonalactone was investigated. Finally, the impact of grape ripening and over-ripening phenomena on 4-hydroxy-2-nonenal content in must was studied.
In conclusion, our results demonstrated the presence of 4-hydroxy-2-nonenal in musts and wines and its biotransformation to γ-nonalactone during alcoholic fermentation of red grape varieties. The role of 4-hydroxy-2-nonenal as a precursor of the odorous γ-nonalactone in wine is revealed for the first time.
(1) Pons, A.; Lavigne, V.; Eric, F.; Darriet, P.; Dubourdieu, D. Identification of Volatile Compounds Responsible for Prune Aroma in Prematurely Aged Red Wines. J. Agric. Food Chem. 2008, 56 (13), 5285–5290.
(2) Allamy, L.; Darriet, P.; Pons, A. Molecular Interpretation of Dried-Fruit Aromas in Merlot and Cabernet Sauvignon Musts and Young Wines: Impact of over-Ripening. Food Chem. 2018, 266, 245–253.
(3) Ferron, P. de; Thibon, C.; Shinkaruk, S.; Darriet, P.; Allamy, L.; Pons, A. Aromatic Potential of Bordeaux Grape Cultivars: Identification and Assays on 4-Oxononanoic Acid, a γ-Nonalactone Precursor. J. Agric. Food Chem. 2020, 68 (47), 13344–13352.
(4) Schneider, C.; Tallman, K. A.; Porter, N. A.; Brash, A. R. Two Distinct Pathways of Formation of 4-Hydroxynonenal. J. Biol. Chem. 2001
Presenting author: Philippine de Ferron – Phd Student -Bordeaux University – Institut des Sciences de la Vigne et du Vin – Unité de Recherche Oenologie EA-4577 – USC 1366 INRA
Additionnal authors: Cécile Thibon | Institut des Sciences de la Vigne et du Vin – Unité de Recherche Oenologie EA-4577 – USC 1366 INRA, Svitlana Shinkaruk | Bordeaux University – Institut des Sciences de la Vigne et du Vin – Unité de Recherche Oenologie EA-4577 – USC 1366 INRA, Alexandre Pons | Bordeaux University – Institut des Sciences de la Vigne et du Vin – Unité de Recherche Oenologie EA-4577 – USC 1366 INRA
Keywords: flavor, γ-nonalactone, precursors, maturity, 4-hydroxy-2-nonenal