Toward a Molecular Understanding of the Typicality of Chardonnay Wines: Identification of Powerful Aromatic Compounds Reminiscent of Hazelnut

Abstract

Chardonnay wines impart a unique complex aroma characterized by its buttery, yellow stone fruit, melon, bready, and woody notes. Among the terms used in the sensory analysis of these wines, this study investigated hazelnut-like attributes. Multidimensional gas chromatography coupled to olfactometry identified five pyrroles reminiscent of hazelnut: 1-ethylpyrrole-2-carboxaldehyde, 1H-pyrrole, 2-acetyl-1H-pyrrole (first identification in wine), 1-methylpyrrole-2-carboxaldehyde, and 1H-pyrrole-2-carboxaldehyde. Quantitative analyses demonstrated their significantly higher abundance in Chardonnay wines. However, they proved irrelevant in sensory terms, given the low amounts measured in wine compared to their olfactory detection threshold. Nevertheless, the presence of methanethiol derivatives from these pyrroles was investigated in wine. 1-Methylpyrrole-2-methanethiol and 1-ethylpyrrole-2-methanethiol were identified and exhibited hazelnut-like aroma. These compounds, which have not been observed in natural products to date, are potent volatile compounds with detection thresholds of 0.7 and 1.4 ng/L, respectively, in model wine. These findings open up promising perspectives concerning the interpretation of the typical aromatic nuances of some Chardonnay wines.

Exploring the Typicality, Sensory Space, and Chemical Composition of Swedish Solaris Wines

“…Often, typicality assessments are combined to sensory descriptive and physico-chemical analyses [22,23]. Different studies have investigated the chemical compounds, volatile and non-volatile, responsible for typical sensorial attributes of a number of relevant wine categories [19,[28][29][30]. However, these compounds are not exclusive to one single grape variety, but their transformation during winemaking and the subsequent interactions with other compounds will contribute to the wine identity [31,32].…”

Vino de Tea (pine heartwood wine) from La Palma (Spain): ethnographic and physic-chemical characterization of a unique fermented product

“…The presence and concentration of varietal aromatic compounds has been used for the differentiation and characterization of wine, in conjunction with secondary aromas [24]. The final net contribution of all these compounds to the final aroma depends on whether their concentration in the wine is above the perception threshold [25].…”

Strategies for the identification and sensory evaluation of volatile constituents in wine

“…By applying it with organomercuric ( p ‐hydroxymercuribenzoic acid, p ‐HMB) trapping, several new volatile thiols ( 23 , 24 ) were extracted from and identified in Bordeaux red wines without any disturbance from polyphenols (Bouchilloux, Darriet, & Dubourdieu, 1998; Bouchilloux, Darriet, Henry et al., 1998). Sequential vacuum distillation, a form of vacuum distillation, has been used to extract several new volatile compounds ( 58 , 59 ) responsible for hazelnut aromas in wines (Gros et al., 2017). This extraction process can be easily performed with common laboratory equipment and allows the throughput of a relatively large volume of wine samples with minimal handling.…”

“…In many cases, direct analysis of crude wine volatile extracts by GC–O/MS is still likely to produce overwhelming amounts of detection signals. For instance, a single run of some crude wine volatile extracts could yield 75–90 odorous zones (OZs) on GC–O (Allamy et al., 2018; Gros et al., 2017) and even greater numbers of MS signals. This makes it difficult to locate a clear OZ or MS peak of interest, even when GC capillary columns of different polarities have been frequently tested.…”