Identification and Organoleptic Contribution of (Z)-1,5-Octadien-3-one to the Flavor of Vitis vinifera cv. Merlot and Cabernet Sauvignon Musts

Abstract

The main goal of this research was to identify key aroma compounds involved in the dried fruits (prune and dried fig) aroma of musts. An odoriferous zone (OZ) was detected by gas chromatography coupled with olfactometry (GC-O) and identified as (Z)-1,5-octadien-3-one (geranium). A quantitation method by SPME-GC-MS (CI, MeOH) was developed and validated for assaying this very fragrant ketone in musts for the first time (LOD, 0.15 ng/L; LOQ, 0.5 ng/L). Concentrations of (Z)-1,5-octadien-3-one in musts marked by dried fruits flavors reached 90 ng/L, thus exceeding its detection threshold (D = 9 ng/L). Moreover, sensory experiments showed that this compound contributes to the dried fig nuance at concentrations ranging from 64 to 96 ng/L. Above that level, it contributes to the geranium nuance of the must. Its affinity with sulfur dioxide was also established; 30 mg/L of sulfur dioxide causes a decrease of concentration of 60%.

Recent advancements in understanding the terroir effect on aromas in grapes and wines

“…Although not an aroma compound, glutathione is of particular importance in aroma expression in wines, because it acts as a preserving agent for white and rosé wine aromas (in particular for volatile thiols) during wine production and ageing. Wines produced in the Bordeaux area showed lower levels of glutathione in warm years, but this effect was not independent of a possible effect of water deficit (Pons et al, 2015;Pons et al, 2017). There is, however, scientific evidence for a temperature effect on glutathione, whereby antioxidant compounds like glutathione and ascorbate tend to decrease in plants under high temperatures (Szymańska et al, 2017).…”

“…Recently, several compounds involved in dried fruit aromas in must and red wines have been identified, including massoia lactone (Pons et al, 2017a), γ-nonalactone and furaneol (Pons et al, 2008), 3-methyl-2,4-nonanedione (MND, Pons et al, 2011) and (Z)-1, 5-octadien-3-one (Allamy et al, 2017). The aromatic expression of this family of compounds is specific to the phenomenon of over-ripening in grapes and is detected in wines resulting from their vinification.…”

“…Low temperatures induce higher levels of (-)-rotundone in Syrah, which is generally an appreciated character of this variety (Zhang et al, 2015a, Zhang et al, 2015bCaputi et al, 2011). High temperatures increase dried fruit aromas in red wine which may lead to decreased aroma complexity and premature ageing (Pons et al, 2017a;Pons et al, 2017b), in particular for Merlot (Allamy et al, 2017;. Some compounds which play an important role in the ageing bouquet of fine red wines, such as DMS and possibly tabanones, are more abundant in wines from Cabernet-Sauvignon and Merlot when grapes ripen in warm conditions (Le Menn et al, 2019).…”

Temperature Variability at Local Scale in the Bordeaux Area. Relations With Environmental Factors and Impact on Vine Phenology

“…It is possible that, in the case of the Bordeaux area, the effect of soil type overrules a potential impact of thermal amplitude. It is also possible that, independently from thermal amplitude, lower maximum temperatures promote grape quality potential: high temperatures induce cooked fruit aromas which are not associated with premium wine quality (Allamy et al, 2017;Pons et al, 2017).…”

Influence of curettage on Esca-diseased <i>Vitis vinifera</i> L. cv. Sauvignon blanc plants on the quality of musts and wines

“…Other volatile components are impacted by the level of berry maturation. The family of lactones proves a good marker of maturity level (Allamy et al, 2017). The lactone smell is described, for example, as "coconut-like" (gamma-octalactone) and "peach-like and milky" (gamma-decalactone) (Câmara et al, 2006).…”