Impact of Closure OTR on the Volatile Compound Composition and Oxidation Aroma Intensity of Sauvignon Blanc Wines during and after 10 Years of Bottle Storage.

The oxygen transfer rate (OTR) of closures is a well-known parameter impacting the quality of Sauvignon blanc wines (SBw) within the first years of storage, but little research has been published on its long-term effects. The chemical changes in oxidation odor intensity in three SBw sealed with natural cork and other closures that had different known OTRs, ranging from <0.1 to 4.

Isolation of Taste-Active Triterpenoids from : Sensory Assessment and Identification in Wines and Spirit.

Six new triterpenoids (-), two known genins ( and ), and five known functionalized triterpenoids (-) were isolated from a heartwood extract. The purification protocol was guided by LC-HRMS by searching for structural analogues of bartogenic acid on the basis of their putative empirical formula. The structures of the new compounds were unequivocally elucidated using HRESIMS and 1D/2D NMR experiments.

Natural allelic variations of Saccharomyces cerevisiae impact stuck fermentation due to the combined effect of ethanol and temperature; a QTL-mapping study.

Background: Fermentation completion is a major prerequisite in many industrial processes involving the bakery yeast Saccharomyces cerevisiae. Stuck fermentations can be due to the combination of many environmental stresses. Among them, high temperature and ethanol content are particularly deleterious especially in bioethanol and red wine production.

Triterpenoids from Quercus petraea: Identification in Wines and Spirits and Sensory Assessment.

Eight new triterpenoids (1-8), the known genin (9), and two known functionalized triterpenoids (10 and 11) were isolated from a Quercus petraea heartwood extract. The structures of the new compounds were unequivocally elucidated using HRESIMS and 1D/2D NMR experiments. Sensory analyses were performed in a non-oaked wine on the pure compounds 1-11.

Taste-guided isolation of sweet-tasting compounds from grape seeds, structural elucidation and identification in wines.

This work aimed at improving knowledge about sweetness in dry wines. Following on from the empirical observations of winegrowers, we assessed the contribution of grape seeds to wine sensory properties. An inductive fractionation method guided by gustatometry was used to isolate and characterize sweet-tasting compounds from grapes.

Study of the contribution of massoia lactone to the aroma of Merlot and Cabernet Sauvignon musts and wines.

Organic extracts of musts and red wines marked by dried fruit and cooked fruit aromas were analyzed by gas chromatography coupled to olfactometry and mass spectrometry. Thanks to this analytical approach we identified a fragrant lactone corresponding to an odorant zone reminiscent of coconut and dried figs as 5,6-dihydro-6-pentyl-2H-pyran-2-one (C10 massoia lactone). Using chiral GC-GC-MS, we show that only the (R)-C10 massoia lactone is found in musts and wines.

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

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.

Taste-Guided Isolation of Bitter Lignans from Quercus petraea and Their Identification in Wine.

Quercoresinosides A and B (1 and 2), two new lignans, were isolated from a toasted Quercus petraea heartwood extract along with a known compound, 3-methoxy-4-hydroxyphenol 1-O-β-d-(6'-O-galloyl)glucopyranoside (3). The purification protocol was based on a taste-guided approach that sought to reveal new bitter compounds released from oak wood into wines and spirits. HRMS and NMR data were used to establish that compounds 1 and 2 are lignan derivatives bearing a glucosyl unit and a galloyl unit at the same positions.

Identification and analysis of piperitone in red wines.

The present study concerns the search for new aroma compounds associated with the flavor of aged and prematurely aged red wines. Sensory descriptive analysis associated with gas chromatography-olfactometry was first performed to find specific odoriferous zones. One of the zones, reminiscent of mint, was found in red wines with a prune flavor.

Development of a quantitation method to assay both lyoniresinol enantiomers in wines, spirits, and oak wood by liquid chromatography-high resolution mass spectrometry.

Wine taste balance evolves during oak aging by the release of volatile and non-volatile compounds from wood. Among them, an enantiomer of lyoniresinol, (+)-lyoniresinol, has been shown to exhibit bitterness. To evaluate the impact of (+)-lyoniresinol on wine taste, a two-step quantitation method was developed and validated.

Identification of S-3-(hexanal)-glutathione and its bisulfite adduct in grape juice from Vitis vinifera L. cv. Sauvignon blanc as new potential precursors of 3SH.

Two main precursors (S-3-(hexan-1-ol)-l-cysteine and S-3-(hexan-1-ol)-l-glutathione) of 3-sulfanylhexanol (3SH, formerly named 3-mercaptohexanol) have been identified so far in grape juice but a correlation between precursor concentrations in grape juices and 3SH concentrations in wines is not always observed. This suggests that there may be other compounds associated with the aromatic potential. In this work, S-3-(hexanal)-glutathione (Glut-3SH-Al) and its bisulfite (Glut-3SH-SO3) adduct were identified in Sauvignon blanc grape juice by liquid chromatography coupled to Fourier transform mass spectrometry experiments.

New Approach for Differentiating Sessile and Pedunculate Oak: Development of a LC-HRMS Method To Quantitate Triterpenoids in Wood.

Oak aging is a crucial step in winemaking during which the organoleptic properties of wine are modified. Various parameters affect the chemical composition of oak wood including botanical origin, which has been previously shown to be a determinant factor. This study focused on the development of a LC-HRMS method to assay four recently discovered taste-active triterpenes (three sweet and one bitter).

How stereochemistry influences the taste of wine: Isolation, characterization and sensory evaluation of lyoniresinol stereoisomers.

Wine expresses its beauty by sending a sensory message to the taster through molecules coming from grapes, yeast metabolism or oak wood. Among the compounds released during barrel aging, lyoniresinol has been recently reported as a relevant contributor to wine bitterness. As this lignan contains three stereogenic carbons, this work aimed at investigating the influence of stereochemistry on wine taste by combining analytical and sensorial techniques.

Fermentative conditions modulating sweetness in dry wines: genetics and environmental factors influencing the expression level of the Saccharomyces cerevisiae HSP12 gene.

Yeast lees influence the organoleptic properties of wines by increasing their sweet taste. This effect is in part due to the protein Hsp12p, which is regulated by different stress response pathways in Saccharomyces cerevisiae. This work investigated the genetics and environmental factors influencing the expression level of the HSP12 gene in an enological context.

Development of an analytical methodology using Fourier transform mass spectrometry to discover new structural analogs of wine natural sweeteners.

Volatile and non-volatile molecules are directly responsible for the thrill and excitement provided by wine-tasting. Their elucidation requires powerful analytical techniques and innovative methodologies. In a recent work, two novel sweet compounds called quercotriterpenosides (QTT) were identified in oak wood used for wine-ageing.

Role of 3-methyl-2,4-nonanedione in the flavor of aged red wines.

GC-MS in chemical ionization mode (CI) was used as a simple, sensitive method for assaying 3-methyl-2,4-nonanedione (MND) in 67 red wines. MND content was shown to be lower in nonoxidized red wines and higher in oxidized red wines, that is, systematically exceeding the perception threshold (62 ng/L). Concentrations up to 340 ng/L in the most oxidized red wines were also evidenced.

Identification of new natural sweet compounds in wine using centrifugal partition chromatography-gustatometry and Fourier transform mass spectrometry.

Sweetness contributes notably to the taste-balance of dry wines and increases during oak-barrel aging owing to the release of natural sweeteners from wood. The search for such taste-active molecules, which are sometimes present at very low concentrations in wine or other complex matrixes, requires both reliable purification tools and powerful identification techniques. Here, we report the development of an original inductive method using centrifugal partition chromatography (CPC) and sensorial analysis.

The grape must non-Saccharomyces microbial community: impact on volatile thiol release.

Several studies have reported the beneficial influence of non-Saccharomyces yeasts and their potential applications in the wine industry, mainly in mixed-culture fermentation with S. cerevisiae. The potential impact of 15 non-Saccharomyces strains from 7 species on 4-methyl-4-sulfanylpentan-2-one (4MSP) and 3-sulfanylhexan-1-ol (3SH) release in model medium and Sauvignon Blanc must was evaluated after partial fermentation.

Determination of 3-methyl-2,4-nonanedione in red wines using methanol chemical ionization ion trap mass spectrometry.

A compound associated with oxidized flavor in red wines was recently-identified as 3-methyl-2,4-nonanedione (MND). In order to quantify it, positive chemical ionization (PCI) in an ion trap was studied using conventional liquid reagents such as methanol, acetonitrile, and acetone, as well as non-conventional liquid reagents such as ethyl acetate, diethyl ether, pentane, isohexane, and heptane. Under laboratory conditions, very different response factors were obtained with MND depending on the gas.

Influence of yeast macromolecules on sweetness in dry wines: role of the saccharomyces cerevisiae protein Hsp12.

Yeast autolysis during lees contact influences the organoleptic properties of wines especially by increasing their sweet taste. Although observed by winemakers, this phenomenon is poorly explained in enology. Moreover, the compounds responsible for sweetness in wine remain unidentified.

3-Sulfanylhexanol precursor biogenesis in grapevine cells: the stimulating effect of Botrytis cinerea.

Volatile thiols, compounds that contribute strongly to the varietal aroma, are present in much higher concentrations in sweet wines than in dry wines. This positive effect, due to the presence of Botrytis cinerea on the berries, in fact results from a strong enrichment of cysteine S-conjugate precursors in botrytized berries. In the present study, a convenient model was investigated to reproduce and therefore study this phenomenon.

Identification of a sotolon pathway in dry white wines.

Sotolon (3-hydroxy-4,5-dimethyl-2(5H)-furanone) is a chiral furanone, an aroma compound known to be responsible for premature-aging flavor in dry white wines. Sotolon generally results from mild oxygenation during bottle aging, and until now, its formation pathways had not been elucidated. The ability of the main precursors described in the literature under very different experimental conditions to produce sotolon was tested.

Reassessment of phenotypic traits for Saccharomyces bayanus var. uvarum wine yeast strains.

Among Saccharomyces yeast, S. cerevisiae and S. bayanus var.

Aromatic potential of botrytized white wine grapes: identification and quantification of new cysteine-S-conjugate flavor precursors.

Sweet wines made from botrytized grapes contain much higher concentrations of volatile thiols, especially 3-sulfanylhexan-1-ol (3SH), than dry white wines. Three new specific volatile thiols (3-sulfanylpentan-1-ol (3SP), 3-sulfanylheptan-1-ol (3SHp), and 2-methyl-3-sulfanylbutan-1-ol (2M3SB) were recently identified in Sauternes wines. Like most volatile thiols, these compounds were almost totally absent from must, mainly being formed during alcoholic fermentation.