We hypothesised that the protection against oxygen (PAO) of must and wine during vinification by avoiding contact with air can preserve the primary volatile organic compounds (VOCs) of Nerello ...Mascalese. PAO was performed in two seasons (2020 and 2021) using carbon dioxide pellets (CO2,s) and gas (CO2,g), inactivated yeasts and ascorbic acid during fermentation; the control wine was made via traditional vinification without adding the aforementioned components. During fermentation, the two winemaking processes mainly differed in terms of the application of aeration during maceration/fermentation in the pump-over and délestage activities, and the care taken to avoid contact with oxygen during racking. In both years, higher concentrations of polyphenols and total anthocyanins were found in the PAO wine (about 16 % and 20 % respectively). The concentrations of nerol, citronellol and geraniol were significantly higher in the PAO wine in both seasons, albeit with small differences which affected the sensory evaluation. The free/bound terpenes ratio was 0.35 (PAO) and 0.55 (Control). Bound C13-norisoprenoids contents were higher than the free ones; in the PAO wine, free 3-oxo-α-ionol and bound vomifoliol concentrations were slightly higher than in the control wine. Thiols were measured in Nerello for the first time. In 2020 in particular, sulfanylhexan-1-ol was present in larger amounts in the PAO wine. Applying PAO in the production of Nerello Mascalese modified certain VOCs, as well as the overall free/bound ratio due to the increase in bound VOCs, thus influencing the aroma of the wine.
Aim: A study on Sauvignon blanc (SB) cultivar in France showed that curettage had an effect on the resilience of GTD grapevines. No experiments, however, have been conducted on its effects on wine ...quality, particularly on white Sauvignon blanc cultivar wines.Methods and results: Grapevines from Sauvignon blanc cultivar that had expressed Esca-foliar symptoms were used for the study, with some of them having been curetted in 2014. Subsequently, bunches from Control (asymptomatic), Curetted and Esca-symptomatic vines were harvested in 2017 and 2018 in order to produce white wine. Technical and chemical results on both must and wine showed that wines from curetted plants were similar to those from asymptomatic vines. There were differences, however, for Esca-diseased vines, where the alcoholic fermentation of musts was faster than for the other modalities. Olfactometry results showed that, for the one-year-old 2017 vintage wines, no differences were detected, although they were for the 2018 vintage.Conclusion: The results of the chemical analyses and wine tasting showed that the wines from curetted and asymptomatic grapevines were similar, and that their quality was the same.Significance of the study: The quality of wines from curetted vines compared to asymptomatic ones was confirmed and validated through chemical and sensory analyses of the must and the one-year-old wines.
Maintaining wine oxidative stability and reducing SO2 addition remains a challenge in white winemaking. This study aimed to evaluate the antioxidant capacity of two yeast derivatives (YDs) with a ...specific composition: one was rich in reducing compounds, including glutathione (YDR), and the other was rich in lipid compounds (YDL). Both YDs were evaluated for their antiradical activity in model wine solution (by the DPPH method) and for their capacity to consume oxygen in model wine solution and in white wine. Antiradical activity in both matrixes and oxygen consumption rate in wine were higher for YDL than for YDR. However, the addition of YDR to wine limited the production of acetaldehyde and preserved glutathione content to a greater extent after wine oxygenation. The sensory analysis confirmed that both YDs, in particular YDL, limited the occurrence of oxidation off-odours when no SO2 was added. These data suggest that the use of YDs could be effectively implemented in low-sulfite winemaking in order to improve the antioxidant protection of white wine.
•The use of yeast derivatives (YDs) as antioxidants in white wine was evaluated.•Antioxidant activity were evaluated by DPPH and Oxygen Consumption Rate method.•The addition of YDs to white wine limited the production of acetaldehyde.•The addition of YDs to white wine permitted to preserve wine glutathione content.•YDs limited the color browning and oxidation off-odours in absence of SO2 addition.
Great Bordeaux red wines are known for their distinctive aging bouquet. However, the nature of volatile chemicals underpinning this sensory expression is not fully understood. This work investigated ...the empyreumatic aging bouquet of a collection of premium Bordeaux red wines using silver-ion (Ag+) solid-phase extraction, cryogenic heart-cutting multidimensional gas chromatography mass spectrometry/olfactometry, and comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry. In doing so, a substantial number of “meaty” odors were revealed. Three detected “meaty” notes were tentatively or unequivocally attributed to furan thiols. Among them, 2-methyltetrahydrofuran-3-thiol (1) with a pleasant “meaty” aroma was reported in wine for the first time. Its trans isomer (trans-1a) was resolved from its racemate by chemical modification, which confirmed its presence in wine. The odor detection threshold of trans-1a in the model wine was determined at 55 ng/L. Moreover, an additive effect between 1 and literature-known 2-methyl-3-furanthiol was observed. By a new ultra high-performance liquid chromatography quadrupole Orbitrap high-resolution mass spectrometry method, the concentration of trans-1a, in addition to those of 2-methyl-3-furanthiol and 2-furfuryl thiol, was measured in the wines at ng/L levels.
•MeSA can be assayed in wines at concentrations over its olfactory detection threshold.•MeSA is extracted during alcoholic fermentation from V.vinifera grape skins and stems.•MeSA in wines can be ...related to grapevine alteration level by several pathogens.
Methyl salicylate (MeSA) is a plant metabolite that induces plant defence resistance and an odorous volatile compound presenting green nuances. This volatile compound was shown to be present in wine samples, sometimes at concentrations above its olfactory detection threshold. MeSA is localized in grapes, particularly in the skins and stems, and is extracted during red wine vinification. It was detected at the highest concentrations in wines of several grape varieties, made from grapes affected by cryptogamic diseases, namely downy mildew caused by Plasmopara viticola, and black rot caused by Guignardia bidwellii. It has also been detected in wines from vines affected by Esca, a Grapevine Trunk Disease. MeSA can also be considered to be a chemical marker in grapes and wine indicative of the level of development of several vine cryptogamic diseases.
Non-Saccharomyces yeasts have been used for many years due to their technological potential, particularly as a “booster” of wine fruity aroma in mixed fermentations with Saccharomyces cerevisiae. ...Recently, a new application has emerged, bioprotection, which consists in colonizing the environment in the context of sulfite reduction in wines. The chemical and sensory impact of non-Saccharomyces yeast according to different modes of application in a context of fermentation without addition of SO2 was evaluated through trial with Merlot N. (Vitis vinifera L.). An effective niche occupation by non-Saccharomyces yeasts was highlighted during the prefermentary stages by Quantitative-PCR and MALDI-TOF MS identification. Chemical analysis (GC-MS and GC MS/MS) of finish wine showed the significant impact of the dose applications, with bioprotection characterized by linear esters and sequential application by acetates of higher alcohol contents. Moreover, a separation according to the species used in bioprotection was revealed. Finally, using a panel trained, the sensory analysis confirmed that the use of non-Saccharomyces yeast was a fruity booster in sequential inoculation and, to a less extent, when used as bioprotection. This study shows for the first time that the use of non-Saccharomyces yeast as a bioprotection has a significant impact on the aromatic profile of wines.
•Occupying the niche by T. delbrueckii as a bioprotection, unlike S. cerevisiae.•The dosage of non-Saccharomyces significantly impact the chemical composition of red wine.•Impact of bioprotection on the chemical and aromatic profile red wine in low SO2.
This study evaluated the impact of closure type on unoaked 100 %-Merlot, oak-aged 70%-Merlot/30%-Cabernet Sauvignon, and 30%-Merlot/70%-Cabernet Sauvignon during a 10 year period. Closures were ...microagglomerate corks, screw caps, and synthetics with the known oxygen transfer rate (OTR), ranging from 0.1 to 4.6 mg/y, including natural corks. Oxidation intensity perception, dissolved oxygen, sulfite, and 3-methyl-2,4-nonanedione (MND) were monitored on a regular basis. After 10 years of aging, additional aroma impact markers were evaluated (3-sulfanylhexan-1-ol, H2S, DMS, methional, and phenylacetaldehyde). Low OTR levels (≤0.3 mg/y) delayed the oxidation of red wines in this long-term experiment. In addition, our results led us to hypothesize that the MND concentration in young wines might be linked with their ability to produce it during bottle aging that is with their aging potential. Finally, we found that the kinetic accumulation of MND in wines was first strongly impacted by its intrinsic composition and thereafter by the OTRT0 of the stopper.
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 4.6 mg/year, were monitored over a 10 year period. During aging, free SO2 and 3-sulfanylhexanol loss, concomitant with increases in dissolved O2, OD420, and sotolon, were correlated with closure OTR levels. After 10 years of aging, sensory analysis was conducted, supported by additional chemical analysis of aroma impact markers, including methional, phenylacetaldehyde, 2-furanmethanthiol, 4-methyl-4-sulfanylpentan-2-one, ethyl-2-sulfanylacetate, and hydrogen sulfide, as well as total SO2 and dissolved CO2. These analyses revealed that selected SBw were protected from oxidation over a 10 year aging period, provided that the closure OTR did not exceed 0.3 mg/year.
•A methodology was developed to choose the liquid reagent in CI–MS/MS.•The sensitivity of CI and EI ionization modes was evaluated.•A simultaneousassayof volatile thiols and aldehydes was performed ...in wines.•The proposed method using GC–MS/MS (EI) is simple and sensitive.
A rapid, sensitive method for assaying volatile impact compounds in white wine was developed using gas chromatography–tandem mass spectrometry (GC–MS/MS) technology, with a triple quadrupole analyzer operating in chemical ionization and electron impact mode. This GC–MS/MS method made it possible to assay volatile thiols (3SH: 3-sulfanylhexanol, formerly 3MH; 3SHA: 3-sulfanylhexyl acetate, formerly 3MHA; 4MSP: 4-methyl-4-sulfanylpentan-2-one, formerly 4MMP; BM: benzenemethanethiol; E2SA: ethyl 2-sulfanylacetate; and 2FM: 2-furanmethanethiol) and odoriferous oxidation markers (Sotolon: 4,5-dimethyl-3-hydroxy-2(5)H-furanone, methional, and phenylacetaldehyde) simultaneously in dry white wines, comparing electron impact (EI) and chemical ionization (CI) modes. More molecular ions were produced by CI than protonated molecules, despite the greater fragmentation caused by EI. So, even using the best reactant gas giving the highest signal for thiols, EI was the best ionization mode, with the lowest detection limits. For all compounds of interest, the limits of quantification (LOQ) obtained were well below their detection thresholds (ranging from 0.5 to 8.5ng/L for volatile thiols and 65–260ng/L for oxidation markers). Recovery rates ranged from 86% to 111%, reproducibility (in terms of relative standard deviation; RSD) was below 18% in all cases, with correlation coefficients above 0.991 for all analytes. The method was successfully applied to the analysis of compounds of interest in Sauvignon Blanc wines from a single estate and ten different vintages.
The development of an aromatic bouquet during fine wine aging depends on complex transformations occurring in a reductive atmosphere, favorable to the formation and preservation of sulfur odorants, ...such as dimethyl sulfide (DMS) and polyfunctional thiols. The aim of this study was to address their role in the occurrence, evolution, and perceived sensory nuances of the aging bouquet of red Bordeaux wines. These compounds were quantified in 24 wines and scored by a professional wine panel for the degree to which they reflected the aging bouquet olfactory concept. Partial least square (PLS) analysis, combining sensory and quantitative chemical data, predicted that DMS, 2-furanmethanethiol, and 3-sulfanylhexanol concentrations correlated with the typicality score, discriminating highly-typical wines from less-typical ones. Several vintages from three vineyards were then subjected to sensory and chemical analysis to determine how aging bouquet typicality and the intensity of five key aromatic notes (undergrowth, truffle, fresh fruit, toasted, and empyreumatic) evolved during bottle storage in relation to these three sulfur odorants. PCA analysis emphasized their combined impact on aging bouquet typicality and their contribution to undergrowth, truffle, and empyreumatic attributes.
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