The quality of white wine is related to sensory attributes like color, odorand taste. This study focused mainly on taste attributes of white wines. The research hypothesis was to find out if taste-related attributes alone, determined by sensory experiment, could discriminate Chardonnay versus non-Chardonnay wines. Sensory analyses were performed with a trained panel on commercial white wines made from single varieties. Black glasses and nose clips were used to remove sensory interference and to first assess only taste attributes. Initial tests were then performed to evaluate the possibility to discriminate against Chardonnay wines only due to taste. In a second series of experiments, Rate All That Apply (RATA) experiments were performed in a set of Chardonnay versus non-Chardonnay wines. An initial sensory experiment revealed that some of the Chardonnay wines could be discriminated against by taste only but that recognition by using olfaction was more powerful which confirmed our research hypothesis in part. The second series of RATA sensory analysis revealed that some specific descriptors such as fat, salt, bitter and acid are involved in the taste discrimination of Chardonnay versus non-Chardonnay wines, especially with Sauvignon Blanc wines. These findings suggest that while modal sensory approach remains more robust for varietal identification, taste alone offers some discriminatory power.

An experiment involving the ageing of Syrah red wine was conducted over a period of 24 months, during which the impact of four different micro-agglomerated corks was examined. An untargeted UHPLC-Q-Orbitrap metabolomics analysis was performed and provided valuable insights into the chemical dynamics of red wine evolution. Forty-three specific discriminating compounds were found for non-aged wines, including various CHO and CHON-types molecules. Thirteen specific discriminating compounds were found for 24-months-aged wines including CHO, CHNOS and CHOS compounds. Among them, sulfonated flavanols and pyranoanthocyanins were identified and emerged as key molecular markers of wine ageing. This metabolomics analysis also enabled us to identify specific chemical markers of cork oxygen transfer rate (OTR) influence. Analysis revealed specific molecules linked to corks with low and high OTR such as anthocyanins and proanthocyanins respectively. This research enhances our comprehension of intricate chemical changes during red wine ageing and underscores the potential impact of cork OTR on wine composition.

A Syrah red wine ageing experiment was set up during 24 months to measure the influence of different microagglomerated corks on wine composition and color. Two new wine ageing indices based on targeting phenolic composition (I-ox, oxidation index and I-su, sulfonation index) or colorimetric one (Hue) are proposed. The results showed that the slopes of evolution of these indices varied according to the wine as well as the index studied, and that the initial composition played a predominant role in these evolutions. In addition, the oxygen transfer rate (OTR) of the cork modulates the rate of evolution of the oxidation index and color, but had no impact on the sulfonation index. Partial least squares (PLS) regressions were used in order to establish some models that can predict the ageing index slope based on accelerated ageing tests (AATs), voltammetric parameters and phenolic composition measured before bottling. The models involved different explaining variables for each test and showed good predictive capacities with correlation coefficients (R-2) > 0.79.

Cork stoppers have a significant impact on aging as a place of gas exchange. This study investigates the effects of different cork closures on red wines using 1H NMR metabolomics approach. The objective is to understand how different cork stoppers affect the chemical evolution of wine during aging. Six Syrah wines from the Côtes du Rhône and Languedoc-Roussillon regions, matured in either steel tanks or oak barrels, were bottled with four micro-agglomerated cork stoppers. Over 24 months, wines were analyzed using 1H NMR spectroscopy. Data were processed using multivariate analyses: principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal projections to latent structures discriminant analysis (OPLS-DA). The analyses revealed significant changes along the wine aging process. Distinct chemical signatures were identified for wines at the initial and 24-month stages. At the initial stage, wine maturation conditions, stainless steel tank or oak barrel, seem to impact wine constituents, including methanol, ethyl lactate, acetic acid, myo-inositol, and isobutanol. Finally, corks with higher oxygen transfer rate (OTR) showed higher content in acetoin, suggesting its application as an oxygenation marker of wines. The findings highlight the complex role of cork permeability in red wine aging, suggesting that the choice of cork can be strategically used to steer the aging process and enhance wine quality.

A Syrah red wine ageing experiment was set up during 24-months and the influence of four micro-agglomerated corks were investigated. Specific phenolic ageing markers were selected and hemi-synthesized: vitisin B, malvidin-ethyl-catechin, and epicatechin-sulfonate. A targeted quantification method of these markers was then developed and validated by using ultra-high performance liquid chromatography - triple quadrupole mass spectrometry (UHPLC-QqQ-MS) operating in MRM (Multiple Reaction Monitoring). Results showed a significant decline in native grape polyphenol levels (anthocyanins, flavanols) as ageing progresses while pyranoanthocyanins, ethyl-linked pigments, and flavanol-sulfonates content increased. The cork oxygen transfer rate emerged as a pivotal factor and had significant effects on polyphenolic concentration evolution but had no significant impact on flavanol-sulfonate formation. These results provide valuable insights into the chemical evolution ongoing during wine ageing, accentuating the pivotal role of cork stopper selection in preserving wine quality over time.

A novel optical fibre device is proposed for real-time measurements of near infrared chromatic refractive index signature of a liquid medium in the 1100-1700 nm range. This inline optical fibre chromatic refractive index analyser is based upon collocated fibre long period gratings written adjacently in the core by femtosecond laser inscription yielding 8 attenuation bands associated with different cladding modes, yielding 8 independent measurements across the entire wavelength range. This fibre device is tested on a series of chemical compounds associated with wines. The results for each compound yielded distinctive chromatic responses. The limits of detection for this fibre devices ranged from 1x10(-3) to 6x10(-5) mol/L for the compounds associated with wines. This demonstrates a potential usefulness of such an optical fibre sensor capable of monitoring in real-time effective chromatic refractive index signatures that is not offered by any current technology.

Metabolic skeletal muscle (SM) dysfunction, triggered by increased oxidative stress and mitochondrial impairment, is a pivotal contributor to obesity-associated insulin resistance (IR). Addressing obesity and SM IR demands substantial lifestyle changes including regular exercise and dietary adjustments that are difficult to follow over time. This prompted exploration of alternative approaches. Grape polyphenols (GPPs) have demonstrated a positive impact on metabolism, although few studies have focused on SM. Since grape polyphenolic content and composition depend on tissue and ripening, we explored the antioxidant potential of GPPs from skin (Sk) and seeds (Sd) extracted before veraison (Bv) and at mature (M) stages, on palmitate-induced IR in primary human SM cells. Despite their important difference in polyphenol (PP) content: Sd-BvPP > Sd-MPP/Sk-BvPP > Sk-MPP, all extracts reduced lipid peroxidation by 44–60%, up-regulated the heme-oxygenase 1 protein level by 75–132% and mitochondrial activity by 47–68%. Contrary to the other extracts, which improved insulin response by 50%, Sd-BvPP did not. Our findings suggest that compounds other than stilbenoids or anthocyanin-type molecules, present only in grape Sk, could play an active role in regulating SM oxidative and metabolic stress and insulin sensitivity, paving the way for further exploration of novel bioactive compounds.

Fourteen Syrah red wines with different initial composition and antioxidant properties (polyphenols, antioxidant capacity, voltammetric behaviour, colour parameters and SO2) were selected. Three different accelerated ageing tests (AATs) were then performed on these wines: thermal test at 60 degrees C (60 degrees C-ATT), enzymatic test with laccase (Laccase-ATT) and chemical test with H2O2 (H2O2-ATT). The results showed high correlations between the initial phenolic composition and antioxidant properties of the samples. Partial least squares (PLS) regressions were used in order to establish some models that can predict the AATs test results based on their different initial composition and antioxidant properties. The PLS regression models had overall very good accuracy and involved different explaining variables for each test. The models taking into account all the measured parameters and the phenolic composition alone showed good predictive capacities with correlation coefficients (r2) > 0.89.

Today, inactivity and high-calorie diets contribute to the development of obesity and premature aging. In addition, the population of elderly people is growing due to improvements in healthcare management. Obesity and aging are together key risk factors for non-communicable diseases associated with several co-morbidities and increased mortality, with a major impact on skeletal muscle defect and/or poor muscle mass quality. Skeletal muscles contribute to multiple body functions and play a vital role throughout the day, in all our activities. In our society, limiting skeletal muscle deterioration, frailty and dependence is not only a major public health challenge but also a major socio-economic issue. Specific diet supplementation with natural chemical compounds such as grape polyphenols had shown to play a relevant and direct role in regulating metabolic and molecular pathways involved in the prevention and treatment of obesity and aging and their related muscle comorbidities in cell culture and animal studies. However, clinical studies aiming to restore skeletal muscle mass and function with nutritional grape polyphenols supplementation are still very scarce. There is an urgent need for clinical studies to validate the very encouraging results observed in animal models.

Dehydrodicatechins resulting from (epi)catechin oxidation have been investigated in different foods and natural products, but they still offer some analytical challenges. The purpose of this research is to develop a method using ultra-high performance liquid chromatography coupled with trapped ion mobility spectrometry and tandem mass spectrometry (UHPLC−ESI−TIMS−QTOF−MS/MS) to improve the characterization of dehydrodicatechins from model solutions (oxidation dimers of (+)-catechin and/or (−)-epicatechin). Approximately 30 dehydrodicatechins were detected in the model solutions, including dehydrodicatechins B with β and ε-interflavanic configurations and dehydrodicatechins A with γ-configuration. A total of 11 dehydrodicatechins B, based on (−)-epicatechin, (+)-catechin, or both, were tentatively identified in a grape seed extract. All of them were of β-configuration, except for one compound that was of ε-configuration. TIMS allowed the mobility separation of chromatographically coeluted isomers including dehydrodicatechins and procyanidins with similar MS/MS fragmentation patterns that would hardly be distinguished by LC-MS/MS alone, which demonstrates the superiority of TIMS added to LC-MS/MS for these kinds of compounds. To the best of our knowledge, this is the first time that ion mobility spectrometry (IMS) was applied to the analysis of dehydrodicatechins. This method can be adapted for other natural products.

B-type procyanidin dimers and (+)-catechin dimeric oxidation products were analyzed in grape seed extracts and red wines (UHPLC-Q-Orbitrap MS). The different dimers had different fragmentation patterns according to their interflavan linkage position. Oxidation dimeric compounds had a specific fragment ion at m/z 393, missing for B-Type dimers fragmentations. A fragment ion at m/z 291 occurred and was specific for oxidation dimeric compounds with a COC linkage. Higher level oxidation products had abundant specific fragments: m/z 425, 397 and 245. These fragmentations were useful to identify them in complex samples such as grape seed extracts and wines. Three grape varieties and three ripening stages were selected and the corresponding seed extracts were obtained. The analyses revealed an increasing trend for the oxidation markers during grape ripening. The analysis of Syrah wines (2018, 2014, 2010) showed a decreasing trend of these molecules during wine ageing which might be due to further oxidation.

Red wine is a very complex medium in which condensed tannins undergo many modifications during winemaking and bottle ageing. These reactions have an impact on the organoleptic properties. This work aimed to highlight tannins evolution related to wine evolution by studying three vintages of Syrah wines. An accelerated oxidation was also undertaken in order to evaluate the ability of this oxidation to imitate natural evolution. After chemical depolymerization of the tannins, the monitoring of 6 types of markers at two oxidation levels was investigated. An evolution of the tannin oxidation state during ageing evidenced by the increase of the markers of the second oxidation level was observed. In the 2018 oxidized wine sample, the first oxidation level markers were similar to the 2014 vintage but the second oxidation level markers were higher than other vintages, indicating a more advanced state of tannin oxidation.

Two experimental Syrah red wines with different polyphenol contents were used to study the impact of acetaldehyde addition on olfactory perception. Free acetaldehyde levels were measured in red wine by Head Space-Gas Chromatography-Mass Spectrometry (HS-GC-MS) to determine the acetaldehyde combination levels for those wines. Significant differences were observed for both sensory threshold and acetaldehyde combination for the wines. A descriptive sensory analysis of the wines was then performed by using a trained panel and a Hierarchical-Check-All-That-Apply (HCATA) analysis of the wines with or without acetaldehyde addition. The results show that classical cited sensory descriptors for acetaldehyde (overripe apple and oxidized apple) varied significantly between the control wines and those with acetaldehyde addition. Non-acetaldehyde related descriptors (fresh vegetable, fresh flowers, cocoa, and meat juice) were also significantly impacted in the samples with increasing acetaldehyde additions. This suggests possible interactions between acetaldehyde and other volatile compounds that can create antagonistic or synergistic effects between the molecules or at the olfactory receptor level.

In order to obtain information on the oxidative behavior of red wines, oxygen consumption rates and electrochemical changes (cyclic voltammetry) were measured for nine red wines subject to three different accelerated ageing tests: chemical (with hydrogen peroxide), enzymatic (with laccase from Trametes versicolor), and temperature (at 60 °C). Oxidative behavior depended both on the wine sample and accelerated ageing test type. A good correlation was observed between electrochemical parameters of charges for reference/non-oxidized wines, in accordance with their antioxidant capacity, and the variation of charges after enzymatic and temperature tests, meaning that cyclic voltammetry could be used in order to predict these two oxidation tests and reflect the wine sensitivity towards respective oxidation targets. However, it was not possible to predict wine chemical oxidation test based on hydrogen peroxide from the electrochemical measurements.

Background: Stilbenes are a group of naturally occurring phenolic compounds. These compounds are synthetized by plants in response of biotic or abiotic stress situations. The major dietary sources of stilbenes for humans are grape berries and wine. To accurately identify and quantify these compounds, the research community has undertaken considerable efforts to optimise samples preparations and analytical methods. In addition, stilbenes are well-known to possess a wide range of biological activities for human health. One of the most recent and promising properties demonstrated by stilbenes are their anti-obesity effects. Scope and approach: The principal objectives of this review are to address and discuss about: i) stilbenes in grape berries and wine, the factors that can modulate their concentrations and the most efficient sample preparation techniques and analytical methods used for their detection; ii) the most important investigations related to the in vitro and in vivo anti-obesity effects of grape and wine stilbenes and the associated molecular mechanisms. Key Findings and Conclusions: Stilbene concentration in grape and wines can vary substantially. The composition of stilbenes in red wine is much more complex than in white wine. Until today, more than 30 stilbenes have been identified in grapes and wines. The liquid chromatography coupled to mass spectrometry is the most efficient method to investigate stilbene content. Regarding anti-obesity properties of stilbenes, a great number of in vitro and in vivo studies have allowed to demonstrate not only the positive implications of these bioactives but also the underlying mechanisms of the observed effects.

(+)-Catechin—laccase oxidation dimeric standards were hemi-synthesized using laccase from Trametes versicolor in a water-ethanol solution at pH 3.6. Eight fractions corresponding to eight potential oxidation dimeric products were detected. The fractions profiles were compared with profiles obtained with two other oxidoreductases: polyphenoloxidase extracted from grapes and laccase from Botrytis cinerea. The profiles were very similar, although some minor differences suggested possible dissimilarities in the reactivity of these enzymes. Five fractions were then isolated and analyzed by 1D and 2D NMR spectroscopy. The addition of traces of cadmium nitrate in the samples solubilized in acetone-d6 led to fully resolved NMR signals of phenolic protons, allowing the unambiguous structural determination of six reaction products, one of the fractions containing two enantiomers. These products can further be used as oxidation markers to investigate their presence and evolution in wine during winemaking and wine ageing.

(1) Background: Both sensory quality and healthy attributes of Vitis vinifera grapes used for winemaking are closely related with the polyphenolic composition of their skins. (2) Methods: In this study, the polyphenolic characterization (flavan-3-ols, procyanidins, flavonols, stilbenes, anthocyanins) was investigated by ultra performance liquid chromatography coupled to a triple quadrupole mass spectrometer (UPLC-QqQ-MS). Skins from Vitis vinifera Merlot, Tannat, and Syrah red grape varieties cultivated in the south of France at different stages of ripening in 2018 were used. The anti-inflammatory and the antioxidant potential of the extracts were evaluated by the measure of nitric oxide (NO) and the intracellular reactive oxygen species production (ROS) in lipopolysaccharide (LPS)-stimulated macrophages. (3) Results: 41 polyphenols were quantified in all samples. Generally, the flavan-3-ol and procyanidin content decreased during ripening whereas the anthocyanins and stilbenes increased. In addition, as a novelty of this work, a wide identification and characterization of monomeric and oligomeric stilbenes was assessed by using authentic standards isolated in our laboratory, some of them (parthenocissin A and miyabenol C) reported for the first time in Merlot, Tannat and Syrah cultivars. The before-veraison skin extracts of all studied varieties, exhibited higher NO and ROS productions inhibition (>50%) proving both antioxidant and anti-inflammatory properties.

Botrytized sweet wines are made with berries infected by the fungus Botrytis cinerea. The aim of this study was to identify biomarkers of B. cinerea infection in sweet wines with a focus on laccases which are exocellular oxidase enzymes produced by this fungus during fruit contamination. Total proteins from six commercial sweet wines, including three naturally botrytized wines and three non-botrytized wines were analysed by LC-QTOF-MS. Five laccases, namely laccase-1-BcLCC1, laccase-2-BcLCC2, laccase-3-BcLCC7, laccase-8-BcLCC8 and laccase-12-BcLCC12, were identified in both types of wine. Then, a targeted proteomic approach by LC-MRM was used to semi-quantify laccase-2-BcLCC2 and laccase-3-BcLCC7, in the six samples. LC-MRM targeted analysis of the two enzymes allowed the discrimination of botrytized versus non-botrytized sweet white wines.

A rapid Ultra Performance Liquid Chromatography coupled with Quadrupole/Time Of Flight Mass Spectrometry (UPLC-QTOF-MS) method was designed to quickly acquire high-resolution mass spectra metabolomics fingerprints for rosé wines. An original statistical analysis involving ion ratios, discriminant analysis, and genetic algorithm (GA) was then applied to study the discrimination of rosé wines according to their origins. After noise reduction and ion peak alignments on the mass spectra, about 14 000 different signals were detected. The use of an in-house mass spectrometry database allowed us to assign 72 molecules. Then, a genetic algorithm was applied on two series of samples (learning and validation sets), each composed of 30 commercial wines from three different wine producing regions of France. Excellent results were obtained with only four diagnostic peaks and two ion ratios. This new approach could be applied to other aspects of wine production but also to other metabolomics studies.