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Denis Dubourdieu - One of the best experts on this subject based on the ideXlab platform.
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New insights into intrinsic and extrinsic factors triggering premature aging in White Wines
2015Co-Authors: Alexandre Pons, Valérie Lavigne, Denis Dubourdieu, Maria Nikolantonaki, Kentaro Shinoda, Philippe DarrietAbstract:Two grape antioxidants, ascorbic acid and glutathione, and a flavan-3-ol, catechin, were analyzed and related to the production or depletion of volatile compounds (phenylacetaldehyde, methional, and sotolon) that act as markers of premature aging in dry White Wines. This research assessed the impact of adding ascorbic acid (AA, 80 mg/L) and glutathione (GSH, 10 mg/L) to a Sauvignon Blanc wine sealed with two closures with different permeability to oxygen on wine flavor development over 10 years’ bottle storage. A decrease in AA was correlated with the closure’s oxygen permeability, while GSH depletion (90 % in 12 months) was associated with the dissolved oxygen content at bottling. Sensory analysis revealed significant differences in the development of wine oxidation flavors, correlated with the closure, as well as AA and GSH content. Wines spiked with AA and GSH at bottling were preferred by panelists to controls, without GSH. The sensory data were in complete agreement with analytical results, showing that these Wines had the lowest sotolon content. We also demonstrated that, on the basis of analyzing the oxidation markers (sotolon, methional, and phenylacetaldehyde), high catechin levels in White Wines contributed to their formation in a temperature-dependent manner.
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Identification of a Sotolon Pathway in Dry White Wines
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Alexandre Pons, Valérie Lavigne, Yannick Landais, Philippe Darriet, Denis DubourdieuAbstract: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 ox...
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Identification of a sotolon pathway in dry White Wines
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Alexandre Pons, Valérie Lavigne, Yannick Landais, Philippe Darriet, Denis DubourdieuAbstract: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. In model wine solution maintained at 40 degrees C for 6 months, sotolon was produced by the oxidative degradation of ascorbic acid. By use of GC-MS, 2-ketobutyric acid, produced by the oxidative degradation of the ascorbic acid in the model wine solution, was identified as a potent precursor of sotolon in this pathway. Ascorbic acid is an exogenous compound, added before bottling, but 2-ketobutyric acid was found even in White Wines that had not been supplemented. Consequently, this sotolon formation pathway is also valid in White Wines with no added ascorbic acid. In addition, we showed that Saccharomyces cerevisiae strains were capable of producing variable concentrations of this ketone during alcoholic fermentation. In model wine solution, certain yeast strains released large quantities of 2-ketobutyric acid, similar to those found in oxidized dry White Wines. In view of these results, the role of yeast strains in this premature-aging phenomenon of dry White Wines is discussed. Finally, these investigations revealed that one chemical mechanism responsible for the low concentrations of sotolon found in prematurely aged White Wines made from various grape varieties was an aldol condensation between 2-ketobutyric acid and acetaldehyde.
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Distribution and organoleptic impact of sotolon enantiomers in dry White Wines.
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Alexandre Pons, Valérie Lavigne, Yannick Landais, Philippe Darriet, Denis DubourdieuAbstract:The enantiomers of sotolon, a flavor compound typical of oxidized White Wines, were separated by preparative HPLC to determine their perception thresholds and distribution in Wines. The enantiomeric ratios of chiral sotolon were evaluated in several dry White Wines using gas chromatography and a chiral column (β-cyclodextrin) connected to a 2 m precolumn (BP20). The perception threshold of (S)-sotolon (0.8 µg/L) in model wine solution was 100 times lower than that of the (R) form (89 µg/L), indicating that (S)-sotolon contributes to the characteristic aroma of prematurely aged dry White Wines. Both enantiomers are detected in White Wines. Analysis of commercial dry White Wines from various vintages and origins revealed three types of distribution patterns: the racemic form, an excess of R, and an excess of S. The proportions found in these Wines may be partially explained by the slow racemization kinetics (20 months) of optically active sotolon.
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Changes in the sotolon content of dry White Wines during barrel and bottle aging.
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Valérie Lavigne, Alexandre Pons, Philippe Darriet, Denis DubourdieuAbstract:GC-MS in electron ionization mode (EI) was used as a simple, sensitive method for assaying sotolon [4,5-dimethyl-3-hydroxy-2(5)H-furanone] in various dry White Wines. The impact of barrel-aging conditions, that is, whether yeast lees were present or not, on the formation of sotolon in dry White Wines was then studied. The sotolon content was highest in dry White Wines aged in new barrels without lees, often exceeding the perception threshold (8 µg/L). These results demonstrated that yeast lees were capable of minimizing the formation of sotolon in dry White Wines during aging. The sotolon and oxygen contents of several bottle of the same White wine were also compared 7 years after bottling. At the range of dissolved oxygen concentrations generally measured, between 5 and 100 µg/L, the sotolon content remained below its perception threshold in wine. The perception threshold was exceeded only in Wines with oxygen concentrations above 500 µg/L. The presence of dissolved oxygen in the wine samples analyzed al...
Régis Gougeon - One of the best experts on this subject based on the ideXlab platform.
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Molecular Characterization of White Wines Antioxidant Metabolome by Ultra High Performance Liquid Chromatography High-Resolution Mass Spectrometry
Antioxidants, 2020Co-Authors: Remy Romanet, Florian Bahut, Maria Nikolantonaki, Régis GougeonAbstract:The 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.
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The Antioxidant Potential of White Wines Relies on the Chemistry of Sulfur-Containing Compounds: An Optimized DPPH Assay
Molecules, 2019Co-Authors: Remy Romanet, Jordi Ballester, Christian Coelho, Youzhong Liu, Florian Bahut, Maria Nikolantonaki, Régis GougeonAbstract:The DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay is an easy and efficient method commonly used to determine the antioxidant capacity of many food matrices and beverages. In contrast with red Wines, White Wines are poorer in antioxidant polyphenolics, and the more hydrophilic sulfur-containing compounds in them may contribute significantly to their antioxidant capacity. The modification of the classical DPPH method, with a methanol-buffer and the measure of EC20 (quantity of sample needed to decrease the initial DPPH concentration by 20%) has shown that sulfur-containing compounds such as cysteine (0.037 ± 0.003), glutathione (0.054 ± 0.003) or methanethiol (0.104 ± 0.003) appeared to bear antioxidant capacity comparable to well known phenolic compounds, such as catechin (0.035 ± 0.003), caffeic acid (0.057 ± 0.003) and ferulic acid (0.108 ± 0.003), respectively. In the case of White Wines, the comparison with REDOX-sensory scores showed that results from this modified DPPH assay are strongly correlated with sensory attributes (r = 0.73, p < 0.1). These results provide an unprecedented illustration of the important contribution of these sulfur-containing compounds to the radical quenching ability of White Wines.
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Molecular and Macromolecular Changes in Bottle-Aged White Wines Reflect Oxidative Evolution–Impact of Must Clarification and Bottle Closure
Frontiers in Chemistry, 2018Co-Authors: Christian Coelho, Jordi Ballester, Maria Nikolantonaki, Perrine Julien, Laurence Noret, Mathilde Magne, Régis GougeonAbstract:Chardonnay Wines from Burgundy, obtained from musts with three levels of clarification (Low, Medium and High) during two consecutive vintages (2009 and 2010) and for two kinds of closures (screw caps and synthetic coextruded closures) were analyzed chemically and sensorially. Three bottles per turbidity level were opened in 2015 in order to assess the intensity of the reductive and/or oxidative aromas (REDOX sensory scores) by a trained sensory panel. The chemical analyses consisted in polyphenols and colloids quantification, followed by a proteomic characterization. For the two vintages, the REDOX sensory scores appeared to be driven both by the type of closure and to a lesser extent by the level of must clarification. Vintages and must racking prefermentative operations were also distinguished by chemical analyses. All White Wines from the lowest must turbidity had the lowest REDOX sensory scores. Such Wines exhibited lower concentrations in tyrosol and grape reaction product and higher concentrations in colloids with relatively low molecular weights. Among these macromolecules, grape proteins were also quantified, two of them exhibiting concentrations in bottled Wines, which were statistically correlated to oxidative evolution in White Wines.
Juan Cacho - One of the best experts on this subject based on the ideXlab platform.
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volatile composition and sensory properties of north west spain White Wines
Food Research International, 2013Co-Authors: Mar Vilanova, Ana Escudero, Maria Grana, Juan CachoAbstract:Abstract The aroma and volatile composition of Wines from five White grape cultivars from NW Spain ( Loureira , Blanco lexitimo , Torrontes , Treixadura and Albarino ) have been studied by gas chromatography–mass spectrometry (GC–MS) and quantitative descriptive analysis (QDA) during three consecutive vintages (2007–2009) in order to characterize these Wines. Relationships between the instrumental (volatile) and sensory variables were analyzed through the application of partial least squares regression (PLS1). The results showed significant differences among White Wines (P 1), thus contributing to the final wine aroma. Partial least squares regression (PLS1) was applied to significant volatile compounds with OAV > 0.2 and significant aroma descriptors with geometric mean (%GM) > 10. PLS1 yielded a satisfactory model for the prediction of three important aroma descriptors in this set of Wines, floral, herbaceous and ripe fruit aromas, and aroma intensity from instrumental analysis data. This work contributes to knowledge about the sensory profiles and its relation to the volatile composition of Galician White grape cultivars.
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analysis occurrence and potential sensory significance of five polyfunctional mercaptans in White Wines
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Laura Mateovivaracho, Juan Cacho, Julian Zapata, Vicente FerreiraAbstract:A previously developed analytical method has been improved, validated and adapted for the analysis of 2-furfurylthiol (FFT), 4-methyl-4-mercapto-2-pentanone (MP), 3-mercaptohexyl acetate (MHA), 3-mercaptohexanol (MH) and benzylmercaptan (BM) in 136 White Wines from different parts of the world. The overall uncertainty of the determinations was found to be around 20%, which was considered satisfactory given the low levels at which these compounds are found. The levels ranged from the method detection limits (0.5; 0.6; 2.0; 8.0 and 0.5 ng/L for FFT, MP, MHA, MH and BM, respectively) to 225; 87.9; 591; 7255 and 131 ng/L, which implies that nearly all of them can reach more than 100 Odor Units in some Wines. The levels are significantly linked to both the grape variety (with the exception of FFT) and to the origin (in the case of Sauvignon Blanc samples), however, the range of variation within groups are so large that clear clusters could not be observed. Different sensory tests carried out on White wine models showed that all these compounds, even at low concentration, play an outstanding role on the aroma of wine, contributing to fruity, fresh and green notes. In some Wines they are at concentrations high enough to act as genuine impact compounds.
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volatile components of zalema White Wines
Food Chemistry, 2007Co-Authors: Jose M Gomezmiguez, Isabel M Vicario, Juan Cacho, Vicente Ferreira, Francisco J HerediaAbstract:Abstract The volatile composition of young White Wines from Vitis vinifera cv. Zalema, an autochthonous grape variety in Huelva (southern Spain), has been studied by gas chromatography-olfactometry (GC-O) and techniques of quantitative analysis. This is the first time that an olfactometric analysis has been reported in Wines made from this grape variety. The quantitative chemical study has shown 71 volatile compounds, of which 23 were in concentrations above their thresholds. On the basis of the odour activity values (OAVs), the most potent odorants were fermentative compounds, mainly fatty acids and their ethyl esters. Two norisoprenoids, β-damascenone and β-ionone, two alcohols (isoamyl alcohol and β-phenylethanol), three volatile thiols, 4-mercapto-4-methyl-2-pentanone, 3-mercaptohexyl acetate and 3-mercapto-1-hexanol, and two carbonyl compounds (acetaldehyde and phenylacetaldehyde) also exhibited OAVs > 1. The GC-O study corroborated these results, showing that five esters (isoamyl acetate, ethyl hexanoate, ethyl butyrate, ethyl isovalerate and ethyl octanoate), isoamyl alcohol and β-damascenone can be considered as the most powerful odorants of Zalema Wines.
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impact odorants of different young White Wines from the canary islands
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Ricardo Lopez, Juan Cacho, Natalia Ortin, Juan P Pereztrujillo, Vicente FerreiraAbstract:Five young monovarietal White Wines from the Canary Islands made from Gual, Verdello, Marmajuelo, White Listan, and Malvasia grape cultivars were studied to determine the characteristics of their most important aromas and the differences among them. The study was carried out using gas chromatography−olfactometry (GC-O) to detect the potentially most important aroma compounds, which were then analyzed quantitatively by gas chromatography−flame ionization detection and gas chromatography−mass spectrometry. The strongest odorants in the GC-O experiments were similar in all cases, although significant differences in intensity between samples were noted. Calculation of the odor activity values (OAVs) showed that 3-mercaptohexyl acetate was the most active odorant in the Marmajuelo and Verdello Wines, as were 3-methylbutyl acetate in the Gual wine, β-damascenone in the Malvasia wine, and ethyl octanoate in the White Listan wine. However, the most important differences between varieties were caused by the three ...
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sensory and chemical changes of young White Wines stored under oxygen an assessment of the role played by aldehydes and some other important odorants
Food Chemistry, 2002Co-Authors: Ana Escudero, Juan Cacho, Esther Asensio, Vicente FerreiraAbstract:Abstract The aroma of young White Wines altered by oxygen was described by a sensory panel which defined the terms: cooked vegetables, liquor, woody, cider and pungent. Twenty-seven young White Wines stored under oxygen for 1 week were analyzed by the sensory panel and were further analyzed by gas chromatography (GC)-Ion trap mass spectrometry (MS) to determine their contents in hexanal, 4-hydroxy-4-methylpentanone, 2-nonanone, 2-buthoxyethanol, t -2-octenal, 1-octen-3-ol, furfural and 5-methylfurfural, benzaldehyde, t -2-nonenal and eugenol. The degrees of aroma degradation induced by oxidation and the acetaldehyde concentration of the Wines were measured before and after the oxidation process. The sensory analysis showed that wine aroma degradation is primarily caused by the appearance of a cooked-vegetable odour nuance. The acetaldehyde content of the Wines did not vary significantly during the oxidation process, and thereby, cannot be related to the appearance of any of the aroma nuances. Regression data confirm the important role played by eugenol in the woody aromatic nuance, but suggest that important odorants, responsible for the other aromatic nuances, remain unidentified. Some of the compounds analyzed may be used as chemical markers for wine oxidative deterioration. The cooked-vegetable odour nuance can be satisfactorily predicted with quantitative measurements of t -2-nonenal, eugenol, benzaldehyde and furfural.
Christian Coelho - One of the best experts on this subject based on the ideXlab platform.
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The Antioxidant Potential of White Wines Relies on the Chemistry of Sulfur-Containing Compounds: An Optimized DPPH Assay
Molecules, 2019Co-Authors: Remy Romanet, Jordi Ballester, Christian Coelho, Youzhong Liu, Florian Bahut, Maria Nikolantonaki, Régis GougeonAbstract:The DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay is an easy and efficient method commonly used to determine the antioxidant capacity of many food matrices and beverages. In contrast with red Wines, White Wines are poorer in antioxidant polyphenolics, and the more hydrophilic sulfur-containing compounds in them may contribute significantly to their antioxidant capacity. The modification of the classical DPPH method, with a methanol-buffer and the measure of EC20 (quantity of sample needed to decrease the initial DPPH concentration by 20%) has shown that sulfur-containing compounds such as cysteine (0.037 ± 0.003), glutathione (0.054 ± 0.003) or methanethiol (0.104 ± 0.003) appeared to bear antioxidant capacity comparable to well known phenolic compounds, such as catechin (0.035 ± 0.003), caffeic acid (0.057 ± 0.003) and ferulic acid (0.108 ± 0.003), respectively. In the case of White Wines, the comparison with REDOX-sensory scores showed that results from this modified DPPH assay are strongly correlated with sensory attributes (r = 0.73, p < 0.1). These results provide an unprecedented illustration of the important contribution of these sulfur-containing compounds to the radical quenching ability of White Wines.
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Molecular and Macromolecular Changes in Bottle-Aged White Wines Reflect Oxidative Evolution–Impact of Must Clarification and Bottle Closure
Frontiers in Chemistry, 2018Co-Authors: Christian Coelho, Jordi Ballester, Maria Nikolantonaki, Perrine Julien, Laurence Noret, Mathilde Magne, Régis GougeonAbstract:Chardonnay Wines from Burgundy, obtained from musts with three levels of clarification (Low, Medium and High) during two consecutive vintages (2009 and 2010) and for two kinds of closures (screw caps and synthetic coextruded closures) were analyzed chemically and sensorially. Three bottles per turbidity level were opened in 2015 in order to assess the intensity of the reductive and/or oxidative aromas (REDOX sensory scores) by a trained sensory panel. The chemical analyses consisted in polyphenols and colloids quantification, followed by a proteomic characterization. For the two vintages, the REDOX sensory scores appeared to be driven both by the type of closure and to a lesser extent by the level of must clarification. Vintages and must racking prefermentative operations were also distinguished by chemical analyses. All White Wines from the lowest must turbidity had the lowest REDOX sensory scores. Such Wines exhibited lower concentrations in tyrosol and grape reaction product and higher concentrations in colloids with relatively low molecular weights. Among these macromolecules, grape proteins were also quantified, two of them exhibiting concentrations in bottled Wines, which were statistically correlated to oxidative evolution in White Wines.
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molecular and macromolecular changes in bottle aged White Wines reflect oxidative evolution impact of must clarification and bottle closure
Frontiers in Chemistry, 2018Co-Authors: Christian Coelho, Jordi Ballester, Maria Nikolantonaki, Perrine Julien, Laurence Noret, Mathilde Magne, Regis D GougeonAbstract:Chardonnay Wines from Burgundy, obtained from musts with three levels of clarification (Low, Medium and High) during two consecutive vintages (2009 and 2010) and for two kinds of closures (screw caps and synthetic coextruded closures) were analyzed chemically and sensorially. Three bottles per turbidity level were opened in 2015 in order to assess the intensity of the reductive and/or oxidative aromas (REDOX sensory scores) by a trained sensory panel. The chemical analyses consisted in polyphenols and colloids quantification, followed by a proteomic characterization. For the two vintages, the REDOX sensory scores appeared to be driven both by the type of closure and to a lesser extent by the level of must clarification. Vintages and must racking prefermentative operations were also distinguished by chemical analyses. All White Wines from the lowest must turbidity had the lowest REDOX sensory scores. Such Wines exhibited lower concentrations in tyrosol and grape reaction product and higher concentrations in colloids with relatively low molecular weights. Among these macromolecules, grape proteins were also quantified, two of them exhibiting concentrations in bottled Wines, which were statistically correlated to oxidative evolution in White Wines.
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fluorescence fingerprinting of bottled White Wines can reveal memories related to sulfur dioxide treatments of the must
Analytical Chemistry, 2015Co-Authors: Christian Coelho, Alissa Aron, Chloe Roulliergall, Michael Gonsior, Philippe Schmittkopplin, Regis D GougeonAbstract:For the first time, Excitation Emission Matrix (EEM) fluorescence spectroscopy was combined with parallel factor statistical analysis (PARAFAC) and applied to a set of 320 dry White Wines of the Chardonnay grape variety. A four component PARAFAC model (C1, C2, C3 and C4) best explained the variability of fluorescence signatures of White Wines. Subtle changes were observed in EEMs of White Wines from two different vintages (2006 and 2007), where different concentrations of sulfur dioxide (0, 4, and 8 g·hL–1) were added to the grape must at pressing. PARAFAC results clearly indicated that sulfur dioxide added to the must subsequently influenced White wine chemistry into three distinct sulfur dioxide dose-dependent aging mechanisms. For both vintages, C1 and C2 were the dominant components affected by sulfur dioxide and likely reacting with phenolic compounds associated with some presumably proteinaceous material. Distinct component combinations revealed either SO2 dependent or vintage-dependent signatures, ...
Maria Nikolantonaki - One of the best experts on this subject based on the ideXlab platform.
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Molecular Characterization of White Wines Antioxidant Metabolome by Ultra High Performance Liquid Chromatography High-Resolution Mass Spectrometry
Antioxidants, 2020Co-Authors: Remy Romanet, Florian Bahut, Maria Nikolantonaki, Régis GougeonAbstract:The 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.
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The Antioxidant Potential of White Wines Relies on the Chemistry of Sulfur-Containing Compounds: An Optimized DPPH Assay
Molecules, 2019Co-Authors: Remy Romanet, Jordi Ballester, Christian Coelho, Youzhong Liu, Florian Bahut, Maria Nikolantonaki, Régis GougeonAbstract:The DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay is an easy and efficient method commonly used to determine the antioxidant capacity of many food matrices and beverages. In contrast with red Wines, White Wines are poorer in antioxidant polyphenolics, and the more hydrophilic sulfur-containing compounds in them may contribute significantly to their antioxidant capacity. The modification of the classical DPPH method, with a methanol-buffer and the measure of EC20 (quantity of sample needed to decrease the initial DPPH concentration by 20%) has shown that sulfur-containing compounds such as cysteine (0.037 ± 0.003), glutathione (0.054 ± 0.003) or methanethiol (0.104 ± 0.003) appeared to bear antioxidant capacity comparable to well known phenolic compounds, such as catechin (0.035 ± 0.003), caffeic acid (0.057 ± 0.003) and ferulic acid (0.108 ± 0.003), respectively. In the case of White Wines, the comparison with REDOX-sensory scores showed that results from this modified DPPH assay are strongly correlated with sensory attributes (r = 0.73, p < 0.1). These results provide an unprecedented illustration of the important contribution of these sulfur-containing compounds to the radical quenching ability of White Wines.
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Molecular and Macromolecular Changes in Bottle-Aged White Wines Reflect Oxidative Evolution–Impact of Must Clarification and Bottle Closure
Frontiers in Chemistry, 2018Co-Authors: Christian Coelho, Jordi Ballester, Maria Nikolantonaki, Perrine Julien, Laurence Noret, Mathilde Magne, Régis GougeonAbstract:Chardonnay Wines from Burgundy, obtained from musts with three levels of clarification (Low, Medium and High) during two consecutive vintages (2009 and 2010) and for two kinds of closures (screw caps and synthetic coextruded closures) were analyzed chemically and sensorially. Three bottles per turbidity level were opened in 2015 in order to assess the intensity of the reductive and/or oxidative aromas (REDOX sensory scores) by a trained sensory panel. The chemical analyses consisted in polyphenols and colloids quantification, followed by a proteomic characterization. For the two vintages, the REDOX sensory scores appeared to be driven both by the type of closure and to a lesser extent by the level of must clarification. Vintages and must racking prefermentative operations were also distinguished by chemical analyses. All White Wines from the lowest must turbidity had the lowest REDOX sensory scores. Such Wines exhibited lower concentrations in tyrosol and grape reaction product and higher concentrations in colloids with relatively low molecular weights. Among these macromolecules, grape proteins were also quantified, two of them exhibiting concentrations in bottled Wines, which were statistically correlated to oxidative evolution in White Wines.
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molecular and macromolecular changes in bottle aged White Wines reflect oxidative evolution impact of must clarification and bottle closure
Frontiers in Chemistry, 2018Co-Authors: Christian Coelho, Jordi Ballester, Maria Nikolantonaki, Perrine Julien, Laurence Noret, Mathilde Magne, Regis D GougeonAbstract:Chardonnay Wines from Burgundy, obtained from musts with three levels of clarification (Low, Medium and High) during two consecutive vintages (2009 and 2010) and for two kinds of closures (screw caps and synthetic coextruded closures) were analyzed chemically and sensorially. Three bottles per turbidity level were opened in 2015 in order to assess the intensity of the reductive and/or oxidative aromas (REDOX sensory scores) by a trained sensory panel. The chemical analyses consisted in polyphenols and colloids quantification, followed by a proteomic characterization. For the two vintages, the REDOX sensory scores appeared to be driven both by the type of closure and to a lesser extent by the level of must clarification. Vintages and must racking prefermentative operations were also distinguished by chemical analyses. All White Wines from the lowest must turbidity had the lowest REDOX sensory scores. Such Wines exhibited lower concentrations in tyrosol and grape reaction product and higher concentrations in colloids with relatively low molecular weights. Among these macromolecules, grape proteins were also quantified, two of them exhibiting concentrations in bottled Wines, which were statistically correlated to oxidative evolution in White Wines.
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New insights into intrinsic and extrinsic factors triggering premature aging in White Wines
2015Co-Authors: Alexandre Pons, Valérie Lavigne, Denis Dubourdieu, Maria Nikolantonaki, Kentaro Shinoda, Philippe DarrietAbstract:Two grape antioxidants, ascorbic acid and glutathione, and a flavan-3-ol, catechin, were analyzed and related to the production or depletion of volatile compounds (phenylacetaldehyde, methional, and sotolon) that act as markers of premature aging in dry White Wines. This research assessed the impact of adding ascorbic acid (AA, 80 mg/L) and glutathione (GSH, 10 mg/L) to a Sauvignon Blanc wine sealed with two closures with different permeability to oxygen on wine flavor development over 10 years’ bottle storage. A decrease in AA was correlated with the closure’s oxygen permeability, while GSH depletion (90 % in 12 months) was associated with the dissolved oxygen content at bottling. Sensory analysis revealed significant differences in the development of wine oxidation flavors, correlated with the closure, as well as AA and GSH content. Wines spiked with AA and GSH at bottling were preferred by panelists to controls, without GSH. The sensory data were in complete agreement with analytical results, showing that these Wines had the lowest sotolon content. We also demonstrated that, on the basis of analyzing the oxidation markers (sotolon, methional, and phenylacetaldehyde), high catechin levels in White Wines contributed to their formation in a temperature-dependent manner.
