38 research outputs found
Impact of Glutathione on Wines Oxidative Stability: A Combined Sensory and Metabolomic Study
This paper is a comprehensive study regarding the role of glutathione as a natural antioxidant on white wines aging potential. It includes sensory and ultrahigh resolution mass spectrometry (FTICR-MS) metabolomics of aged chardonnay wines from 2008 to 2009 vintages, made after glutathione spiking at alcoholic fermentation or bottling. The closure effect was also considered. The sensory analysis revealed a clear vintage, closure and glutathione effect on wines oxidative character after several years of bottle aging. Spearman rank correlation was applied to link the sensory analysis and the exact mass information from FT-ICR-MS. FTICRâMS along with multivariate statistical analyses put in evidence that glutathione efficiency against wines sensory oxidative stability is related to wines antioxidant metabolome consisting of N- and S- containing compounds like amino acids, aromatic compounds and peptides. The chemical composition and origin of wines antioxidant metabolome suggests that its management since the very beginning of the vinification process is a key factor to estimate wines aging potential
Incidence of phenolic compounds oxidation on white wine aromatic component
Les rĂ©actions d'oxydation impliquant les composĂ©s phĂ©noliques semblent induire des modifications non nĂ©gligeables du profil chimique et sensoriel des vins. Les travaux concernent lâĂ©tude des mĂ©canismes rĂ©actionnels impliquant certains thiols volatils, contributeurs de lâarĂŽme distinctif et de la complexitĂ© des vins des diffĂ©rents cĂ©pages avec les composĂ©s phĂ©noliques oxydĂ©s des vins blancs, principalement les flavan-3-ols. En solution modĂšle de composition proche du vin, une rĂ©activitĂ© diffĂ©rente des thiols volatils selon leur nature chimique vis Ă vis des formes oxydĂ©es des flavan-3-ols a Ă©tĂ© Ă©tablie. La synthĂšse et la caractĂ©risation des adduits par RMN entre les principaux composĂ©s phĂ©noliques des moĂ»ts et des vins blancs et le 3-sulfanylhexanol, prĂ©sentant des nuances dâagrumes, a ensuite Ă©tĂ© rĂ©alisĂ©e en conditions dâoxydation chimique et enzymatique. La suivi cinĂ©tique de la formation des adduits par CLHP-ESI-SM a permis de mettre en Ă©vidence une rĂ©activitĂ© du thiol spĂ©cifique vis Ă vis dâun substrat polyphĂ©nolique, dâĂ©tablir le rĂŽle catalytique des mĂ©taux (Fe2+) et la capacitĂ© antioxydante du dioxyde de soufre vis Ă vis de ces mĂ©canismes rĂ©actionnels. La comprĂ©hension de mĂ©canismes fondamentaux de la rĂ©activitĂ© de la (+)-catĂ©chine et de la (-)-Ă©picatĂ©chine en conditions Ćnologiques avec les thiols volatils nous a permis de dĂ©cliner les travaux Ă lâĂ©tude de lâinfluence de la prĂ©sence des flavan-3-ols au cours de la vinification et de lâĂ©levage des vins sur ces composants de lâarĂŽme des vins blancs.Oxidation reactions involving phenolics might change wines chemical and sensory profile. The present work concern the study of reactional mechanisms implying certain volatile thiols, responsible of distinctiveness and complexity of various wines, with white wines oxidized phenolic compounds, mainly flavan-3-ols. In a model wine solution, a different volatile thiol reactivity pattern according to their chemical nature with respect to oxidized flavan-3-ols forms was established. The adducts synthesis and characterization by NMR between the principal white musts and wines phenolic compounds and the 3-sulfanylhexanol, presenting citrus fruits nuances, were carried out under chemical and enzymatic oxidation conditions. Their formation monitoring by HPLC-ESI-MS highlighted a specific reactivity of thiol with polyphenolic substrate and established the catalytic role of metals (Fe2+) as well as, the antioxidant effect of sulphur dioxide into these mechanisms. The comprehension of fundamental mechanisms for the reactivity of (+)-catechin and of (-)-epicatechin with volatile thiols in oenological conditions enabled us to elucidate the influence of flavan-3-ols into white wines aroma compounds during wine making and ageing
Incidence de lâoxydation des composĂ©s phĂ©noliques sur la composante aromatique des vins blancs
Oxidation reactions involving phenolics might change wines chemical and sensory profile. The present work concern the study of reactional mechanisms implying certain volatile thiols, responsible of distinctiveness and complexity of various wines, with white wines oxidized phenolic compounds, mainly flavan-3-ols. In a model wine solution, a different volatile thiol reactivity pattern according to their chemical nature with respect to oxidized flavan-3-ols forms was established. The adducts synthesis and characterization by NMR between the principal white musts and wines phenolic compounds and the 3-sulfanylhexanol, presenting citrus fruits nuances, were carried out under chemical and enzymatic oxidation conditions. Their formation monitoring by HPLC-ESI-MS highlighted a specific reactivity of thiol with polyphenolic substrate and established the catalytic role of metals (Fe2+) as well as, the antioxidant effect of sulphur dioxide into these mechanisms. The comprehension of fundamental mechanisms for the reactivity of (+)-catechin and of (-)-epicatechin with volatile thiols in oenological conditions enabled us to elucidate the influence of flavan-3-ols into white wines aroma compounds during wine making and ageing.Les rĂ©actions d'oxydation impliquant les composĂ©s phĂ©noliques semblent induire des modifications non nĂ©gligeables du profil chimique et sensoriel des vins. Les travaux concernent lâĂ©tude des mĂ©canismes rĂ©actionnels impliquant certains thiols volatils, contributeurs de lâarĂŽme distinctif et de la complexitĂ© des vins des diffĂ©rents cĂ©pages avec les composĂ©s phĂ©noliques oxydĂ©s des vins blancs, principalement les flavan-3-ols. En solution modĂšle de composition proche du vin, une rĂ©activitĂ© diffĂ©rente des thiols volatils selon leur nature chimique vis Ă vis des formes oxydĂ©es des flavan-3-ols a Ă©tĂ© Ă©tablie. La synthĂšse et la caractĂ©risation des adduits par RMN entre les principaux composĂ©s phĂ©noliques des moĂ»ts et des vins blancs et le 3-sulfanylhexanol, prĂ©sentant des nuances dâagrumes, a ensuite Ă©tĂ© rĂ©alisĂ©e en conditions dâoxydation chimique et enzymatique. La suivi cinĂ©tique de la formation des adduits par CLHP-ESI-SM a permis de mettre en Ă©vidence une rĂ©activitĂ© du thiol spĂ©cifique vis Ă vis dâun substrat polyphĂ©nolique, dâĂ©tablir le rĂŽle catalytique des mĂ©taux (Fe2+) et la capacitĂ© antioxydante du dioxyde de soufre vis Ă vis de ces mĂ©canismes rĂ©actionnels. La comprĂ©hension de mĂ©canismes fondamentaux de la rĂ©activitĂ© de la (+)-catĂ©chine et de la (-)-Ă©picatĂ©chine en conditions Ćnologiques avec les thiols volatils nous a permis de dĂ©cliner les travaux Ă lâĂ©tude de lâinfluence de la prĂ©sence des flavan-3-ols au cours de la vinification et de lâĂ©levage des vins sur ces composants de lâarĂŽme des vins blancs
Incidence of phenolic compounds oxidation on white wine aromatic component
Les rĂ©actions d'oxydation impliquant les composĂ©s phĂ©noliques semblent induire des modifications non nĂ©gligeables du profil chimique et sensoriel des vins. Les travaux concernent lâĂ©tude des mĂ©canismes rĂ©actionnels impliquant certains thiols volatils, contributeurs de lâarĂŽme distinctif et de la complexitĂ© des vins des diffĂ©rents cĂ©pages avec les composĂ©s phĂ©noliques oxydĂ©s des vins blancs, principalement les flavan-3-ols. En solution modĂšle de composition proche du vin, une rĂ©activitĂ© diffĂ©rente des thiols volatils selon leur nature chimique vis Ă vis des formes oxydĂ©es des flavan-3-ols a Ă©tĂ© Ă©tablie. La synthĂšse et la caractĂ©risation des adduits par RMN entre les principaux composĂ©s phĂ©noliques des moĂ»ts et des vins blancs et le 3-sulfanylhexanol, prĂ©sentant des nuances dâagrumes, a ensuite Ă©tĂ© rĂ©alisĂ©e en conditions dâoxydation chimique et enzymatique. La suivi cinĂ©tique de la formation des adduits par CLHP-ESI-SM a permis de mettre en Ă©vidence une rĂ©activitĂ© du thiol spĂ©cifique vis Ă vis dâun substrat polyphĂ©nolique, dâĂ©tablir le rĂŽle catalytique des mĂ©taux (Fe2+) et la capacitĂ© antioxydante du dioxyde de soufre vis Ă vis de ces mĂ©canismes rĂ©actionnels. La comprĂ©hension de mĂ©canismes fondamentaux de la rĂ©activitĂ© de la (+)-catĂ©chine et de la (-)-Ă©picatĂ©chine en conditions Ćnologiques avec les thiols volatils nous a permis de dĂ©cliner les travaux Ă lâĂ©tude de lâinfluence de la prĂ©sence des flavan-3-ols au cours de la vinification et de lâĂ©levage des vins sur ces composants de lâarĂŽme des vins blancs.Oxidation reactions involving phenolics might change wines chemical and sensory profile. The present work concern the study of reactional mechanisms implying certain volatile thiols, responsible of distinctiveness and complexity of various wines, with white wines oxidized phenolic compounds, mainly flavan-3-ols. In a model wine solution, a different volatile thiol reactivity pattern according to their chemical nature with respect to oxidized flavan-3-ols forms was established. The adducts synthesis and characterization by NMR between the principal white musts and wines phenolic compounds and the 3-sulfanylhexanol, presenting citrus fruits nuances, were carried out under chemical and enzymatic oxidation conditions. Their formation monitoring by HPLC-ESI-MS highlighted a specific reactivity of thiol with polyphenolic substrate and established the catalytic role of metals (Fe2+) as well as, the antioxidant effect of sulphur dioxide into these mechanisms. The comprehension of fundamental mechanisms for the reactivity of (+)-catechin and of (-)-epicatechin with volatile thiols in oenological conditions enabled us to elucidate the influence of flavan-3-ols into white wines aroma compounds during wine making and ageing
White Wine Antioxidant Metabolome: Definition and Dynamic Behavior during Aging on Lees in Oak Barrels
White winesâ oxidative stability is related to a flow of chemical reactions involving a number of native wine compounds comprising their antioxidant metabolome. By applying the combination of powerful and modern analytical approaches (EPR, DPPH, and UPLC-qToF-MS-based metabolomics), we could define wine antioxidant metabolome as the sum of molecular antioxidant markers (AM) characterized by their radical scavenging (AM-RS) and nucleophilic (AM-Nu) properties. The impact of on-lees barrel aging of chardonnay wines on the antioxidant metabolome was studied for two consecutive vintages. The identification of winesâ antioxidant metabolome allows for a detailed understanding of the transient chemical interplays involved in the antioxidant chemistry associated with well-known antioxidants and opens an avenue towards personalized winemaking. The present study gathers for the first time the dynamics of winesâ antioxidant metabolome during on-lees aging. Monitoring the variations of the wine antioxidant metabolome can provide an avenue to better control the winemaking process using the knowledge of how to optimize the wine aging potential
Molecular Characterization of White Wines Antioxidant Metabolome by Ultra High Performance Liquid Chromatography High-Resolution Mass Spectrometry
International audienceThe knowledge about the molecular fraction contributing to white wines oxidative stability is still poorly understood. However, the role of S- and N-containing compounds, like glutathione and other peptides, as a source of reductant in many oxidation reactions, and acting against heavy metals toxicity, or lipid and polyphenol oxidation as ROS-scavenger is today very well established. In that respect, the aim of the present study is to introduce an original analytical tool for the direct determination of the available nucleophilic compounds in white wine under acidic pH conditions. One step derivatization of nucleophiles has been realized directly in wines using 4-methyl-1,2-benzoquinone (4MeQ) as an electrophilic probe. Derivatization conditions considering probe concentration, pH, reaction time, MS ionisation conditions and adducts stability, were optimized using model solutions containing standard sulfur and amino compounds (GSH, Cys, HCys and Ser-Aps-Cys-Asp-Ser, Asp-Met, Met and Glu). Ultra-high-performance liquid chromatography coupled to a quadrupole-time of flight mass spectrometer (UHPLC-QqTOF-MS) analysis of up to 92 white wines from different cultivars (Chardonnay, Sauvignon and Semillon) followed by Multivariate analysis (PLS DA) and Wilcoxon test allowed to isolate up to 141 putative wine relevant nucleophiles. Only 20 of these compounds, essentially thiols, were detectable in samples before derivatization, indicating the importance of the quinone trapping on the revelation of wine unknown nucleophiles. Moreover, annotation using online database (Oligonet, Metlin and KEGG) as well as elementary formula determined by isotopic profile, provided evidence of the presence of amino acids (Val, Leu, Ile, Pro, Trp, Cys and Met) and peptides with important antioxidant properties. The complimentary set of MS/MS spectral data greatly accelerated identification of nucleophiles and enabled peptides sequencing. These results show that probing wines with 4-methyl-1,2-benzoquinone enhances thiols ionisation capacity and gives a better screening of specific S- N- containing functional compounds as part of the white wines antioxidant metabolome
Inoculation of Torulaspora delbrueckii as a bio-protection agent in winemaking
International audienceIn oenology, bio-protection consists in adding bacteria, yeasts or a mixture of microorganisms on grape must before fermentation in order to reduce the use of chemical compounds such as sulphites. More particularly, non-Saccharvinyces yeasts are used as a total or partial alternative to sulphites. However, scientific data capable of proving the effectiveness of adding these yeasts on grape must is lacking. This study reports the analysis of antimicrobial and antioxidant effects of one non-Saccharamyces yeast, Torulaspora delbruecicii, inoculated at the beginning of the white winemaldng process in two Burgundian wineries as an alternative to sulphiting. The implantation of the T. delbrueckii strain was successful in both wineries and had no impact on fermentation kinetics. Adding T. delbrueckii reduced biodiversity during the pre -fermentation stages compared to sulphited controls and it also effectively limited the development of spoilage microorganisms in the same way as the addition of sulphites. T. delbrueckii could protect must and wine from oxidation as demonstrated by the analysis of colour and phenolic compounds. This is the first evidence that early addition of T. ddbrueckii during wine making can be a microbiogical and chemical alternative to sulphites. However, its contribution seems to be matrix dependent
Direct Analysis of Free and Sulfite-Bound Carbonyl Compounds in Wine by Two-Dimensional Quantitative Proton and Carbon Nuclear Magnetic Resonance Spectroscopy
Recent
developments that have accelerated 2D NMR methods and improved
quantitation have made these methods accessible analytical procedures,
and the large signal dispersion allows for the analysis of complex
samples. Few natural samples are as complex as wine, so the application
to challenges in wine analysis look promising. The analysis of carbonyl
compounds in wine, key oxidation products, is complicated by a multitude
of kinetically reversible adducts, such as acetals and sulfonates,
so that sample preparation steps can generate complex interferences.
These challenges could be overcome if the compounds could be quantified <i>in situ</i>. Here, two-dimensional (<sup>1</sup>Hâ<sup>1</sup>H) homonuclear and heteronuclear (<sup>13</sup>Câ<sup>1</sup>H) single quantum correlations (correlation spectroscopy,
COSY, and heteronuclear single quantum coherence, HSQC) nuclear magnetic
resonance spectra of undiluted wine samples were observed at natural
abundance. These techniques achieve simultaneous direct identification
and quantitation of acetaldehyde, pyruvic acid, acetoin, methylglyoxal,
and α-ketoglutaric acid in wine with only a small addition of
D<sub>2</sub>O. It was also possible to observe and sometimes quantify
the sulfite, hydrate, and acetal forms of the carbonyl compounds.
The accuracy of the method was tested in wine samples by spiking with
a mixture of all analytes at different concentrations. The method
was applied to 15 wine samples of various vintages and grape varieties.
The application of this method could provide a powerful tool to better
understand the development, evolution, and perception of wine oxidation
and insight into the impact of these sulfite bound carbonyls on antimicrobial
and antioxidant action by SO<sub>2</sub>
Sulfonation Reactions behind the Fate of White Wineâs Shelf-Life
White wineâs oxidative stability after several years of bottle aging is synonymous to its organoleptic quality. In order to gain control over the cascade of chemical reactions that are implicated in that phenomenon, fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS)-based metabolomics and sensory evaluation were combined for the analysis of a vertical series of white wines from different vineyard plots. Data mining using supervised cluster analysis allowed the extraction of known and unknown sulfur- and nitrogen-containing molecular features, with oxidative stability molecular markers presenting an increased number of S and O atoms in their formulas. In their majority, S-containing molecular features possessed between 4 to ~12 O atoms, indicating the relatively higher importance of sulfonation reactions as opposed to dimerization reactions. Molecular networking, based on sulfonation reaction transformations, evidences the importance of hitherto unknown and/or minor sulfur dioxide binders (peptides, aldehydes, and polyphenols) on wineâs oxidative stability
Antioxidant activity from inactivated yeast: Expanding knowledge beyond the glutathione-related oxidative stability of wine
International audienceMaintaining wine oxidative stability during barrel ageing and shelf life storage remains a challenge. This study evaluated the antioxidant activities of soluble extracts from seven enological yeast derivatives (YDs) with increased glutathione (GSH) enrichment. YDs enriched in GSH appeared on average 3.3 times more efficient at quenching radical species than YDs not enriched in GSH. The lack of correlation (Spearman correlation ÏÂ =Â 0.46) between the GSH concentration released from YDs and their radical scavenging activity shed light on other non-GSH compounds present. After 4-methyl-1,2-benzoquinone derivatization, UHPLC-Q-ToF MS analyses specifically identified 52 nucleophiles potentially representing an extensive molecular nucleophilic fingerprint of YDs. The comparative analysis of YD chemical oxidation conditions revealed that the nucleophilic molecular fingerprint of the YD was strongly correlated to its antiradical activity. The proposed strategy shows that nucleophiles co-accumulated with GSH during the enrichment of YDs are responsible for their antioxidant activities