Impact of oak tannin selection and barrel toasting on the oxidative stability of dry white wine

International audience; The article focuses on the impact of selecting barrel toasting and oak tennin on the dry white wine's oxidative stability. It reports that the management of the barrel ageing is the most important step for the production of premium quality wines and its role in the micro-oxygenation and enrichment of odorant compounds. The oak wood contains the antioxidant capacity. The barrel ageing on the oxidative stability of white wine includes experimental setup, analysis and chemical profiles.

Molecular Characterization of White Wines Antioxidant Metabolome by Ultra High Performance Liquid Chromatography High-Resolution Mass Spectrometry

International audience; 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-met…

Biovi : a research program for reducing chemical input in vine and wine

Decrease of chemical inputs during vine management and winemaking is of great importance from a political and societal point of view. In our ongoing project we propose alternative tools to chemicals in the vineyard and the cellar. We have compared a conventional vineyard protection strategy to an alternative strategy using copper and biocontrol products (Biocontrol) against downy and powdery mildews. Both strategies were compared regarding sanitary quality, berries and/or must enological parameters, and physical, biochemical and biological characteristics (berry surface observation, proteomic, metabolomic, volatilomic, metagenomic analyses). Musts obtained with both strategies were then use…

An Off-On-Off Fluorescent Sensor for pH Windows Based on the 13aneN4-Zn 2+ System

International audience; The new ligand L was prepared and features a 13-membered tetraaza macrocyclic ring with a 1,8-naphthalimide fluorophore appended to a C atom of its backbone. The protonation constants of L as well as its complexation constants with Zn2+ ions were determined in 1:1 water/methanol solutions by potentiometric titrations. Fluorimetric pH titrations were performed with L alone and L in the presence of Zn2+ ions (1:1), and the species distributions (%) versus pH were compared. A window-shaped fluorescence trend was observed with pH for the L/Zn2+ system, which behaves as an off-on-off pH sensor. The on window is centred in the 6.5-7.5 pH range, in correspondence with the f…

MOOC : "Open Wine University 2"

Plan du cours Semaine 1 : Introduction Entre sol et climat Micro-organismes du vin Premiers pas en dégustation + support sur la vinification des vins blancs et des vins rouges Semaine 2 : Le vin en danger ? Climat et viticulture Principales maladies et ravageurs de la vigne Economie mondiale du vin après la crise du phylloxéra Semaine 3 : Façonner le vin Géologie et sols des terroirs bourguignons Vin et diversité microbienne Marchés du vin Semaine 4 : Maîtriser son terroir Construction du terroir de la vigne Vinification des vins spéciaux : l'exemple de la production de vins jaunes du Jura Défauts du vin Semaine 5 : Mettre le vin à table Mise en bouteille du vin Vieillissement du vin Le vin…

The Antioxidant Potential of White Wines Relies on the Chemistry of Sulfur-Containing Compounds: An Optimized DPPH Assay

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 &plusmn

Molecular and Macromolecular Changes in Bottle-Aged White Wines Reflect Oxidative Evolution–Impact of Must Clarification and Bottle Closure

This article is part of the Research Topic "The Chemistry of Wine Ageing" Adresse de correspondance: Institut Universitaire de la Vigne et du Vin, Dijon, France PMCID: PMC5897750; International audience; 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 poly…

Inoculation of Torulaspora delbrueckii as a bio-protection agent in winemaking

International audience; In 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 implantati…

Impact of Oak Wood Barrel Tannin Potential and Toasting on White Wine Antioxidant Stability

International audience; Wines aged in oak wood barrels with various uniform tannin contents (which were classified according to their total ellagitannins contents as predicted by Near Infrared Spectroscopy on the untoasted wood) and different toasting levels (high precision toasting by radiation) were distinguished according to their overall abilities to resist against oxidation. Wine trials were carried out on two different vintages (2015, 2016) and three grape varieties (Sauvignon blanc, Sémillon, Chardonnay). Regardless of the vintage and the wine matrix, a relationship was established between wine oxidative stability (based on EPR spin trapping methodology) and oak barrel tannin potenti…

L'uB au coeur de la viticulture durable

SPEIPMUB; Ancrée au cœur d’une région viticole historique, l’université de Bourgogne soutient de multiples projets de recherche viti-vinicoles et s’investit dans la formation des futurs professionnels du secteur. Elle est d’ailleurs la seule université française à disposer d’un domaine expérimental, situé à Marsannay-la-Côte. En activité depuis 1955, il apporte à la fois un support pédagogique aux étudiants de l’institut Jules Guyot, qui y effectuent différentes manipulations en conditions réelles, et répond à des demandes d’expérimentations émanant des viticulteurs et vignerons de la région. Dans ce cadre, il teste de nouveaux produits, matériaux ou micro-organismes susceptibles de mieux p…

Quinone Reactions in Wine Oxidation

Sulfites and the Wine Metabolome

International audience; In a context of societal concern about food preservation, the reduction of sulfite input plays a major role in the wine industry. To improve the understanding of the chemistry involved in the SO2 protection, a series of bottle aged Chardonnay wines made from the same must, but with different concentrations of SO2 added at pressing were analyzed by ultrahigh resolution mass spectrometry (FT-ICR-MS) and excitation emission matrix fluorescence (EEMF).Metabolic fingerprints from FT-ICR-MS data could discriminate wines according to the added concentration to the must but they also revealed chemistry-related differences according to the type of stopper, providing a wine me…

Corrigendum to ‘Inoculation of Torulaspora delbrueckii as a bio-protection agent in winemaking’ [Food Research International, Inoculation of Torulaspora delbrueckii as a bio-protection agent in winemaking, Volume: 107 (2018), 451–461]

Measurement of white wines resistance against oxidation by Electron Paramagnetic Resonance spectroscopy

International audience; Free radical theory of aging hypothesizes that oxygen-derived radicals are responsible for the storage-related flavor instability in wine. In an optimal situation, a balanced-distribution exists between oxidants and antioxidants among wines intrinsic/extrinsic metabolites. Based on the kinetic study of POBN-1-hydroxyethyl spin adduct (POBN-1-HER) formation in wines initiated via the Fenton reaction, a novel tool based on EPR spin trapping methodology was developed to quantify wines resistance against oxidation. Antioxidant capacities of wines were evaluated according to POBN-1-HER maximum signal intensity (Imax POBN-1-HER) and rate formation (r(POBN-1-HER)) kinetic p…

Direct NMR evidence for the dissociation of sulfur-dioxide-bound acetaldehyde under acidic conditions: Impact on wines oxidative stability

Abstract SO2 reaction with electrophilic species present in wine, including in particular carbonyl compounds, is responsible for the reduction of its protective effect during wine aging. In the present study, direct 1H NMR profiling used to monitor the reactivity of SO2 with acetaldehyde under wine-like oxidation conditions. The dissociation of acetaldehyde bound SO2 was evidenced suggesting that released free SO2 can further act as an antioxidant. EPR and DPPH assays showed an increasing antioxidant capacity of wine with the increase in the concentration of acetaldehyde sulfonate. The presence of acetaldehyde sulfonate in wines was correlated with the overall antioxidant activity of wines.…

Design of new sensitive α,β-unsaturated carbonyl 1,8-naphtalimide fluorescent probes for thiol bioimaging

International audience; We report herein an efficient synthesis of news naphtalimide-based fluorescent derivatives functionalized with an a,(3-unsaturated carbonyl group. Probes were synthesized from reaction of an amino-naphtalimide precursor with maleic anhydride. Photophysical study of fluorescent probes and cells labelling were performed, and showed that the reactive derivatives exhibit rich turn on fluorescence properties in presence of different biological thiol (Glutathione and Cysteine) making these systems a very promising way for thiol bioimaging.

CCDC 1054357: Experimental Crystal Structure Determination

Related Article: Nicolas Sok, Maria Nikolantonaki, Stephane Guyot, Thanh Dat Nguyen, Anne-Sophie Viaux, Franck Bagala, Yoann Rousselin, Florence Husson, Régis Gougeon, Rémi Saurel|2017|Sens.Actuators,B|242|865|doi:10.1016/j.snb.2016.09.171

CCDC 1054356: Experimental Crystal Structure Determination

Related Article: Nicolas Sok, Maria Nikolantonaki, Stephane Guyot, Thanh Dat Nguyen, Anne-Sophie Viaux, Franck Bagala, Yoann Rousselin, Florence Husson, Régis Gougeon, Rémi Saurel|2017|Sens.Actuators,B|242|865|doi:10.1016/j.snb.2016.09.171