Migration of polyphenols from natural and microagglomerated cork stoppers to hydroalcoholic solutions and their sensory impact

During bottling aging, the wine comes into contact with the cork stopper due to the horizontal position of the bottle. The release of compounds, such as cork phenolic compounds, thus take place between the cork and the wine, depending on the type of cork stopper and the surface treatments applied. Many publications describe the extraction of these phenolic compounds in wine or hydroalcoholic solutions from natural corks, but few address microagglomerated corks, which are increasingly used by winemakers to seal their bottles. The aim of this study was therefore to compare the polyphenols, mainly hydrolysable tannins, transferred from natural and microagglomerated corks treated with supercritical CO2 into hydroalcoholic solutions. For this purpose, polyphenols released in macerates of natural and microagglomerated cork stoppers were identified and quantified by HPLC-DAD-ESI-QQQ. Suberic acid was also quantified. In this study, despite the high intra-“natural cork stopper” variability, significant differences were found between both types of stoppers for all polyphenols, the agglomerated corks releasing significantly less polyphenols; i.e., 25 times less. In contrast, suberic acid was extracted from both types of corks in similar concentrations; therefore, its extractability was not impacted by the type of stopper. A sensory profile was also carried out on the macerates. Macerates of natural cork stoppers were perceived with notes of “cardboard, dust, plank, wood” and “cork taint” significantly higher than supercritical CO2 treated microagglomerated cork stopper macerates. Moreover, the natural cork macerate with the highest content in polyphenol was perceived as being more bitter than that of microagglomerated cork stoppers

Phenolic Compounds of Grapes and Wines: Key Compounds and Implications in Sensory Perception

Phenolic compounds are a wide family of thousands of natural bioactives well-known for their overwhelming demonstrated health benefits. Particularly in wines, polyphenols and quality are closely interconnected. Indeed, these compounds possess a critical role due to their contribution to organoleptic wine quality as color, astringency, and bitterness. The profile or the composition of certain polyphenols has been even proposed as an analytical tool for authenticity certification. In this sense, although important progress has been achieved, the understanding of the relationship between the quality of a particular wine and its phenolic composition remains one of the major challenges in enology research. But why? If there is an adjective to define wine, it is “complex.” This final complexity of a wine begins with the enormous polyphenolic variability that may be present in grapes influenced by ripening, genetic, or environmental factors, among others. Winemaking process (alcoholic and malolactic fermentation) and wine aging with or without wood contact produce endless reactions giving rise to complex transformations (copigmentation, cycloaddition, polymerization, and oxidation) of polyphenols. This chapter gathers the most relevant information about the composition, variations, and transformations of phenolic compounds from grape to wine including their influence on sensory properties

J. Agric. Food Chem.

Stilbene metabolites are attracting great interest because many of them exhibit similar or even stronger biological effects than their parent compounds. Furthermore, the metabolized forms are predominant in biological fluids; therefore, their study is highly relevant. After hemisynthesis production, isolation, and structural elucidation, three glucuronide metabolites for oxyresveratrol (ORV) were formed: trans-ORV-4′-O-glucuronide, trans-ORV-3-O-glucuronide, and trans-ORV-2′-O-glucuronide. In addition, two glucuronide metabolites were obtained for gnetol (GN): trans-GN-2′-O-glucuronide and trans-GN-3-O-glucuronide. When the metabolism of ORV and GN is studied in vitro by human and rat hepatic enzymes, four of the five hemisynthesized compounds were identified and quantified. Human enzymes glucuronidated preferably at the C-2′ position, whereas rat enzymes do so at the C-3 position. In view of these kinetic findings, rat enzymes have a stronger metabolic capacity than human enzymes. Finally, ORV, GN, and their glucuronide metabolites (mainly at the C-3 position) decreased nitric oxide, reactive oxygen species, interleukin 1β, and tumor necrosis factor α production in lipopolysaccharide-stimulated macrophages

Réactivité, synthèse, couleur et activité biologique d'Ellagitannins C-glycosidiques et Flavano-Ellagitannins

Les composés phénoliques sont des substances qui jouent un rôle important en oenologie. Ils sont responsables de la couleur et de l'astringence des vins. Les polyphénols présents dans le vin sont majoritairement des flavonoïdes qui proviennent du raisin, mais dans le cas des vins de qualité, l'élevage en fûts de chêne permet au vin de s'enrichir en composés extractibles du bois et notamment en ellagitannins C-glycosidiques. Au cours de ce travail, le mécanisme postulé pour l'évolution des ellagitannins C-glycosidiques dans le vin a été démontré par la formation de divers produits de substitution nucléophile entre la vescalagine et différents nucléophiles. L'hemisynthèse des flavano-ellagitannins a été réalisée en milieu organique par condensation entre la vescalagine et les flavan-3-ols correspondants. Leur formation a également été montrée en milieu hydroalcoolique modèle du vin. L'hémisynthèse d'anthocyano-ellagitannins et de thioléther d'ellagitannin a également été réalisée

Réactivité, synthèse, couleur et activité biologique d'ellagitannins C-glycosidiques et flavano-ellagitannins

Les vins de qualité son généralement élevé en fûts de chêne pendant 6 à 18 mois ce qui permet au vin d'améliorer ces qualités organoleptiques. Au cours de ce contact avec le bois, le vin s'enrichit en ellagitannins C-glycosidiques. Au cours de ce travail, nous nous sommes notamment intéressés au mécanisme d'évolution des ellagitannins C-glycosidiques en milieu acide conduisant à formation de divers produits de substitution nucléophile entre la vescalagine et différents nucléophiles présent dans le vin. L'hemisynthèse des flavano-ellagitannins (les acutissimines et les épiacutissimines) a été réalisée par une substitution nucléophile en milieu acide entre la vescalagine et la catéchine ou l'épicatechine. Leurs identifications et leurs dosages dans un vin rouge élevé en fûts de chêne a été effectuées par HPLC-ESI-MS. L'orientation stéréospécifique de l'attaque nucléophile sur le carbocation intermédiaire a été rationalisé par modélisation moléculaire. L'hémisynthèse du premier membre d'une nouvelle famille de composés, les anthocyano-ellagitannins, a également été réalisé par la condensation entre la malvidine et la vescalagine. La formation de ces produits dans le vin représente la première hypothèse vérifiée de l'évolution chimique des ellagitannins C-glycosidiques dans les vins.Great red wines are generally aged in oak barrels for a period from 6 to 18 months, which contributes to improve their organoleptic quality. During this contact with wood in the barrel the wine solution extracts many substances including some C-glucosidic ellagitannins. During this work, we focused on the evolution of C-glucosidic ellagitannins in acidic medium leading to the formation of various products from nucleophilic substitution reactions with vescalagine and various nucleophilic species present in wine. The hemisynthesis of flavano-ellagitannins (acutissimins and epiacutissimins) was achieved via a nucleophilic substitution reaction between vescalagin and catechin and epicatechin in an acidic medium. Their identification and quantification in a red wine aged in oak barrel were carried out by HPLC-ESI-MS. The remarkable stereospecificity of these substitution reactions was examined by molecular modelling of the benzylic cation intermediate. The hemisynthesis of the first member of a new class of compounds called anthocyano-ellagitannins was achieved via a nucleophilic substitution reaction between vescalagin and malvidin. This new complex shows a bathochromic shift of about 15 nm compared to the maximum wavelength of the initial anthocyanin.BORDEAUX1-BU Sciences-Talence (335222101) / SudocSudocFranceF

Structures of polymeric pigments in red wine and their derived quantification markers revealed by high‐resolution quadrupole time‐of‐flight mass spectrometry

Rationale The quantification of polymeric pigment families in red wine through their derived quantification markers released during phloroglucinolysis will allow the understanding of their formation kinetics and evolutions during aging which has not been achieved until now and is in urgent need. The identification of these quantification markers was achieved by high‐resolution mass spectrometry (HRMS) in this study. Methods HRMS was used to clarify the fragmentation patterns in positive mode of polymeric pigments and identify their derived quantification markers released during phloroglucinolysis. Results With HRMS, identification of (epi)catechin‐malvidin‐3‐O‐glucoside adducts was simplified to MS/MS, and the fragmentation pattern of malvidin‐3‐O‐glucoside‐(epi)catechin adducts was clearly demonstrated. The attribution of four detected ions at m/z 1071.2765 in red wine to the trimeric structure of (epi)catechin‐[malvidin‐3‐O‐glucoside‐A type linkage‐(epi)catechin] and [malvidin‐3‐O‐glucoside‐A type linkage‐(epi)catechin]‐(epi)catechin was achieved for the first time by MS/MS and evidence given by phloroglucinolysis. Moreover, four kinds of derived quantification markers released from polymeric pigments during phloroglucinolysis were also identified. Conclusions The fragmentation pathways of polymeric pigments in red wine and their derived quantification markers released during acidic chemical depolymerisation were clarified which will allow their quantification in red wine

Color Characterization of Bordeaux Red Wines Produced without Added Sulfites

Nowadays, the development of naturalness as a concept is illustrated in the oenological field by the development of wine produced with lower inputs, sometimes even without any addition of SO2 throughout the winemaking process, up to the bottling stage. Despite the increase in the offer of these wines, they remain poorly explored in the literature and require characterization. This study was developed to evaluate the color of Bordeaux red wines without SO2 addition using colorimetric and polymeric pigments analysis. From a batch of commercial Bordeaux red wines with and without SO2 addition, and experimental wines produced from homogenous grapes according to different winemaking processes, colorimetric analyses (CIELab and color intensity (CI)) revealed a large difference in wine color depending on the presence or absence of SO2. Indeed, wines without SO2 were significantly darker and presented with a deeper purplish color. According to these observations, polymeric pigments were quantified using UPLC-DAD/ESI QTof, and a higher concentration of polymeric pigments bound by the ethylidene bridge was observed in wines without SO2. This correlated with differences observed for CIELab and CI. Finally, a comparison with polymeric tannins bound by ethylidene bridge was made and revealed that no differences were observed between wines with and without added SO2. This underlines the affinity difference between tannins and anthocyanins to react with acetaldehyde to form ethylidene bridges

J. Agric. Food Chem.

A solid-phase extraction method was applied for the identification of a series of unconventional crown (macrocyclic) B-type proanthocyanidin tetramers (m/z 1169.2557, 1185.2507, 1201.2456, and 1217.2405) and pentamers (m/z 1457.3191, 1473.3140, 1489.3090, 1505.3039, and 1521.2988) containing (epi)catechins only (procyanidins) or (epi)catechins and (epi)gallocatechins (prodelphinidins). These compounds were identified in red wine by high-performance liquid chromatography–high-resolution mass spectrometry coupled with online hydrogen/deuterium exchange (HDX) after purification with a C18 solid-phase extraction phase from the original wine sample. The number and type of monomer units present in each procyanidin and prodelphinidin are discussed on the basis of the experimental measured masses, their retention time distribution among observed isomers, tandem mass spectrometry fragmentations, and the HDX-induced shift of the theoretical monoisotopic mass. The elution in reverse-phase high-performance liquid chromatography shifted to lower retention times when the ratio of (epi)gallocatechin units in these molecules increased with respect to the content of (epi)catechin units, as a consequence of the increase of polarity

Anthocyanin composition and extraction from Grenache noir (<em>Vitis vinifera</em> L.) vine leaf using an experimental design. I - By ethanol or sulfur dioxide

Aim: Anthocyanins are water soluble pigments mainly located in grape skin; however, these phenolic compounds are also located in vine leaves. The aim of this work was to identify, quantify and determine for the first time the anthocyanin composition in Grenache noir (Vitis vinifera) leaves. Methods and results: Five anthocyanins were identified and quantified in Grenache noir leaves by HPLC-UV-MS. Of these, cyanidin-3-O-glucoside and peonidin-3-O-glucoside were the main anthocyanins and represented 44 and 37%, respectively, while delphinidin-3-O-glucoside, petunidin-3-O-glucoside and malvidin-3-O-glucoside accounted for only 6, 5 and 8%, respectively. A multi-factorial design experiment was used to build a mathematical model to estimate the best extraction condition (highest anthocyanin extraction yield from leaf extract) for both SO2 and ethanol in the aqueous extraction solvent. For SO2, the optimal extraction parameters were an extraction time ranging between 5.77 and 6 h, a temperature ranging between 20 and 23.7°C and a concentration of 500 ppm of SO2 in the aqueous extraction solvent. Using the hydro-alcoholic extraction solvent, the optimal extraction parameters were an extraction time ranging between 3 and 4.37 h, a temperature set at 20°C and an ethanol concentration in the extraction solvent ranging between 32 and 40%. Conclusion: Only the five mono-glucoside anthocyanins usually detected in grapes have been detected, indentified and quantified in Grenache noir leaves by HPLC-UV-MS. Using a multi-factorial design experiment the optimum conditions for the extraction of these anthocyanins were obtained in hydro-alcoholic solution (i.e., extraction time ranging between 3 and 4.37 h, a temperature set at 20°C and an ethanol concentration ranging between 32 and 40%) and in water with SO2 (i.e., extraction time ranging between 5.77 and 6 h, a temperature ranging between 20 and 23.7°C and a concentration of 500 ppm of SO2 in water). Significance and impact of the study: Five anthocyanins were detected, identified and quantified in Grenache noir leaves by HPLC-UV-MS and the main anthocyanin were with cyanidin-3-O-glucoside and peonidin-3-O-glucoside. Th

Anthocyanins composition and extraction from Grenache noir (<em>Vitis vinifera</em> L.) vine leaf using an experimental design II- by ethanol or sulfur dioxide in acidified water

Aim: Anthocyanins are water soluble pigments located in grape skin as well as in vine leaves. The aim of this work was to identify, and determine the anthocyanin composition in Grenache noir (Vitis vinifera) leaves as well as to estimate the optimum conditions leading to the highest anthocyanin extraction yield. Methods and results: Five anthocyanins were identified and quantified in Grenache noir leaves by HPLC-DAD-MS. Among these anthocyanins, cyanidin-3-O-glucoside and peonidin-3-O-glucoside were the main anthocyanins, representing 43 and 38 %, respectively, while delphinidin-3-O-glucoside, petunidin-3-O-glucoside and malvidin-3-Oglucoside accounted for only 6, 5 and 8 %, respectively. To estimate the highest anthocyanin extraction yield, a multi-factorial design experiment was used to build a mathematical model. The extraction conditions tested were time, temperature and solvent composition (i. e., ethanol or SO2 level in acidified water). Conclusion: Only the five mono-glucoside anthocyanins usually detected in grapes have been detected, identified and quantified in Grenache noir leaves. The optimum extraction conditions of these anthocyanins were obtained for acidified hydro-alcoholic solution (i. e., pH 2, 3 h, temperature ranging between 36.5 and 40 °C and an ethanol concentration ranging between 36.8 and 40 %) and for acidified water with SO2 (i. e., pH 2, between 5.8 and 6 h, a temperature ranging between 38.6 and 40 °C and a concentration of 500 ppm of SO2). Significance and impact of the study: Five mono-glucoside anthocyanins were identified and quantified in Grenache noir leaves. The optimum extraction conditions for of these anthocyanins were estimated in acidified hydroalcoholic solution and in acidified water with SO2. These extraction procedures will allow further investigation of the potential use of these anthocyanins as natural pigment for food as well as for the pharmaceutical and cosmetic industry