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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. • An UHPLC-Q-Orbitrap metabolomic analysis was used to identify wine ageing markers. • Specific CHO and CHON-types molecules discriminated young from aged wines. • An increase in CHO, CHONS and CHOS compounds with ageing time was evidenced. • Pyranoanthocyanins are significant ageing and cork oxygen transfer markers. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of three different cold maceration times on the color, volatiles, and sensory of Syrah wine. The results showed that the physicochemical parameters were not influenced by maceration time. Extending the maceration time significantly increased the color intensity and decreased the hue of the wines. The content of monomeric anthocyanins and monomeric phenols increased gradually with the prolongation of immersion time, however, there was no significant difference between 72 and 120 h. Malvidin-3- O -glucoside was the most abundant monomer in anthocyanins, accounting for 67 % of the total content. Moreover, the highest flavanol content (95.42 ± 0.66 mg/L) was found in 120-h sample. The aroma contents of wines macerated for 72 and 120 h were significantly higher than that of 24 h (p < 0.05). Sensory evaluations showed that extended maceration enhanced the color intensity and floral-fruity aromas of the Syrah wines, while increasing astringency. • Different cold maceration time significantly affect the quality of Syrah wine. • Extended maceration time significantly increases the color intensity of wines. • The content of phenols increases with the maceration time prolongs. • Extended maceration time increased the volatiles of wine, especially esters. • 72 h maceration is beneficial for obtaining suitable color and flavor of wine. [ABSTRACT FROM AUTHOR]

• A UHPLC-QqQ-MS method to quantify selected polyphenols was developed and validated. • Different polyphenol kinetics patterns were observed during 24 months of ageing. • The cork OTR influenced the evolution of polyphenols during bottle ageing. • Specific polyphenol wine oxidation markers were evidenced. 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. [ABSTRACT FROM AUTHOR]

Highlights • 1H NMR and LC-MS unveiled the chemical variability of red and white wines. • Secondary metabolites were influenced by seasonality, training system and rootstock. • Primary metabolites were influenced only by seasonality. • Harvest season was the main factor of variability for both varietal wines. • The effect of rootstocks was basically on caffeic acid derivatives. Abstract São Francisco River Valley (SFRV) is a wine-producing semi-arid region in Brazil. Therefore, we used a 1H NMR and UPLC-MS-based metabolomic approach coupled to chemometrics to evaluate the variability in Chenin Blanc and Syrah wines for two harvest seasons, two vine training system and six rootstocks. Overall, the secondary metabolites were influenced by the three factors studied, whereas the primary metabolites were only by the seasonality. Chenin Blanc wines made in December presented higher content of an unidentified carbohydrate. In Syrah wines, glycerol, tartaric acid, succinic acid and 2,3-butanediol were greater in December, while proline and lactic acid were more abundant in July. For training system, caffeic acid derivatives were increased in wines produced from espalier. Lyre system increased phenolic compounds, organic acids and apocarotenoids. The effect of the rootstocks was less pronounced, affecting basically caffeic acid derivatives. Thus, we expect that our results may assist the winemakers to improve the SFRV wine quality. [ABSTRACT FROM AUTHOR]

Highlights • Tannase and cellulase in conjunction enhance grape pomace extraction of phenolics. • Optimization provides practical enzyme doses, time and temperature for the extraction. • Gallic acid liberation by tannase raises grape pomace extracts antioxidant capacity. • Cellulase favours the liberation of p -coumaric acid and malvidin-3- O -glucoside. • Cellulase and tannase simultaneously employed favour the liberation of phenolic acids. Abstract Phenolic compounds are highly valuable products that remain trapped in grape pomace, an abundant winery by-product. Therefore, efficient extraction procedures of these compounds represent a route for grape pomace valorisation. Here we performed a screening of the factors affecting the aqueous enzymatic extraction of phenolic compounds from Syrah grape pomace, including the following independent variables: temperature, pH, pectinase, cellulase and tannase; and a subsequent optimization through response surface methodology. At the optimal region, the enzymatic treatment enhanced the extraction yield of phenolics by up to 66% and its antioxidant capacity by up to 80%, reducing the incubation time and enzyme doses in respect to previous studies. We found that tannase raises the antioxidant capacity of the extract by the liberation of gallic acid, while cellulose favours the liberation of p -coumaric acid and malvidin-3- O -glucoside. We also tested the procedure in different grape pomace varieties, verifying its wide applicability. [ABSTRACT FROM AUTHOR]

• Ageing tests (60 °C-ATT, Laccase-ATT and H 2 O 2 -ATT) were applied to Syrah red wines. • The results of the tests were independent from each other. • Composition and antioxidant parameters could predict the results of the three tests. • PLS models were precise and powerful to predict these tests. Fourteen Syrah red wines with different initial composition and antioxidant properties (polyphenols, antioxidant capacity, voltammetric behaviour, colour parameters and SO 2) were selected. Three different accelerated ageing tests (AATs) were then performed on these wines: thermal test at 60 °C (60 °C-ATT), enzymatic test with laccase (Laccase-ATT) and chemical test with H 2 O 2 (H 2 O 2 -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. [ABSTRACT FROM AUTHOR]

This study reports the effect of different doses of nitrogen applied to soil and/or leaves of Syrah and Chardonnay grapevines in the Languedoc-Roussillon (France) over two years. In 2011, nitrogen treatment involved both foliar urea sprayings and soil application at two different levels, with two controls – irrigated without nitrogen and no irrigation nor nitrogen. In 2012, the same grapevines received either soil or foliar nitrogen using the same controls. Results showed that foliar application increased the amino acid content to a greater extent than soil application, but that a combination of both was the most effective. For the first time, significantly elevated proline levels in response to drought were demonstrated for the grapevine. Increased contents of aromatic compounds and glycosylated precursors closely mirrored the applied nitrogen dose. Wines produced from N-fertilized Syrah grapes in 2011 showed a statistically significant effect of irrigation and fertilization on positive sensorial perception. [ABSTRACT FROM AUTHOR]

[Display omitted] • Methoxypyrazines are not present in Shiraz grape but are in bunch stem (rachis) • Rootstock can influence methoxypyrazine (MP) concentrations in the rachis of Shiraz. • Vine vigour associated with rootstock had positive correlations with MPs in rachis. • Exclusion of sunlight from bunches increased MP concentrations in rachis. • Terroir (related to climate, soil, vine management) also influences MPs in rachis. Vitis vinifera L. cv Shiraz appears unable to synthesise 3-alkyl-2-methoxypyrazines (MPs) in the berry, but can still produce significant concentrations in rachis. MPs are readily extracted from rachis during fermentation, producing Shiraz wines with uncharacteristic "green" flavours. Recently, rootstocks were shown to significantly alter MP concentrations in Cabernet Sauvignon rachis compared to own-rooted varieties, but whether Shiraz followed a similar trend required investigation. This study considered the effect of thirteen rootstocks on the concentrations of 3-isobutyl-2-methoxypyrazine (IBMP), 3-isopropyl-2-methoxypyrazine (IPMP), and 3- sec -butyl-2-methoxypyrazine (SBMP) in the rachis of Shiraz bunches sampled during multiple vintages across several Australian growing regions. Although IBMP was the most abundant, all measured MP concentrations were significantly affected by vintage, rootstock, and region. In addition, vine vigour showed positive correlations with IBMP, which were attributed to changes in canopy coverage impacting rachis light exposure. This hypothesis was explored with light exclusion trials, which significantly increased rachis IBMP concentrations. [ABSTRACT FROM AUTHOR]

• Dealcoholized red wine (DW) was reformulated with flower extracts (FEs). • FEs had no adverse effect on the chemical parameters of the DW. • FEs significantly improved the aroma profile and sensory quality of the DW. • Rose FE had the greatest impact on aroma compounds and sensory acceptance of the DW. There is an increasing market share of dealcoholized wines due to rise in patronage by wine consumers. However, the aroma of such wines deteriorates the more the alcohol content is reduced. Improving the aroma with edible flowers may curb this problem. To improve the aroma of a dealcoholized Merlot red wine, extracts of peach, rose, and lily flowers (FEs) were added to develop three reconstituted dealcoholized wines (RDWS). RDWS were compared with the original wine and the dealcoholized wine (DW) based on chemical properties, aroma compounds, and sensory characteristics. The FEs had no effect on the chemical parameters of RDWS. The FEs improved the volatile composition of RDWS, especially ethyl octanoate, isoamyl octanoate, linalool, and geraniol. Sensory analysis showed that aroma intensity and fruity and floral notes improved in RDWS compared to DW. Among the FEs, rose was the best and can improve the aroma of dealcoholized Merlot red wine. [ABSTRACT FROM AUTHOR]

• Rosé musts from three varieties showed different phenolic compositions and colors. • Depending on must compositions, different fermentation impacts were highlighted. • Changes involved anthocyanin conversion to derived pigments and adsorption on lees. • Anthocyanin reactions during Syrah must fermentation had limited impact on color. • Adsorption of higher molecular weight pigments on lees resulted in color loss. Rosé wines show large color diversity, due to different phenolic pigment compositions. However, the mechanisms responsible for such diversity are poorly understood. The present work aimed at investigating the impact of fermentation on the color and composition of rosé wines made from Grenache, Cinsault, and Syrah grapes. Targeted MS analysis showed large varietal differences in must and wine compositions, with higher concentrations of anthocyanins and flavanols in Syrah. UV–visible spectrophotometry and size exclusion chromatography data indicated that Grenache and Cinsault musts contained oligomeric pigments derived from hydroxycinnamic acids and flavanols which were mostly lost during fermentation due to adsorption on lees. Syrah must color was mainly due to anthocyanins which were partly converted to derived pigments through reactions with yeast metabolites with limited color drop during fermentation. This work highlighted the impact of must composition, reflecting varietal characteristics, on changes occurring during fermentation and consequently wine color. [ABSTRACT FROM AUTHOR]

The effect of adding an enzymatic hydrolysate of grape seeds (EH-GS) during Syrah wine fermentation in a warm climate has been evaluated. We focused on the polyphenolic composition as well as the application of differential and tristimulus colorimetry to colour data. This is the first attempt at using this oenological alternative to avoid common colour losses of red wines elaborated in a warm climate. The addition of 250 g (simple dose, SW) of EH-GS to 120 kg of fermentation material promoted a significant ( p < 0.05) increase in the polyphenolic content of stored wines, especially in benzoic acid, hydroxycinnamic acid derivative, flavonol and anthocyanin levels. This increase could promote a higher copigmentation percentage and maximum colour stabilization ( C ∗ ab ) without significantly changing the wine tonality. Unexpectedly, the use of a double quantity (DW) of EH-GS resulted in significantly less chroma than for control wines (CW), demonstrating visually perceptible colour changes (Δ E ∗ ab > 3 CIELAB units). [ABSTRACT FROM AUTHOR]

The effects of pH and Cu 2+ treatment on the formation of volatile sulfur compounds (VSCs) were investigated in Chardonnay and Shiraz wine samples. Four VSCs were significantly affected by pH, with lower wine pH associated with decreased hydrogen sulfide (H 2 S), methanethiol, dimethyl sulfide, and carbon disulfide concentrations. The effects of pH and Cu 2+ on H 2 S formation from known precursor compounds were subsequently studied in a model wine system. In samples treated with cysteine and glutathione lower pH produced less H 2 S. Nanoparticle tracking analysis was used to study the effects of variable pH concentrations in a model system containing Cu 2+ , tartaric acid, and H 2 S. Differences in Cu 2 + –tartrate complexes particle size and concentration were measured as a function of pH and H 2 S addition, suggesting the type of complexes formed may affect the binding sites of Cu 2+ available to catalyse the formation of VSCs such as H 2 S. [ABSTRACT FROM AUTHOR]

[Display omitted] • Shading reduced sugar accumulation in berries and alcohol levels in resulting wines. • Red and black nets increased the tannins, flavanols and aromatic volatiles of wines. • Wines made from net-covered grapes showed an improvement in sensory characteristics. • The red net was associated with the highest comprehensive score among the treatments. To improve the quality of grapes and wine in warm viticulture regions, the effects of pearl, red and black photoselective nets on the quality of grapes and wine were systematically investigated. Compared with the CK (open field), three nets improved the microclimate conditions and reduced grape sugar and wine alcohol levels. However, the nets differentially affected other quality profiles of the grapes and wine. The pearl net reduced the total flavanol contents in grapes and total aromatic volatiles in wine. The red net increased the total flavanol, tannin and total aromatic volatile contents in wine by approximately 40%, 95% and 10%, respectively, and the percentages for the black net were 30%, 45% and 3%, respectively. The red and pearl nets were more inclined to improve the taste and aroma sensory qualities of wine than the black net did. The red net had the highest comprehensive scores via principal component analysis. [ABSTRACT FROM AUTHOR]

Wine oligosaccharides were recently characterized and their concentrations, their composition and their roles on different wines remain to be determined. The concentration and composition of oligosaccharides in Cabernet Sauvignon, Syrah and Monastrell wines was studied. Oligosaccharide fractions were isolated by high resolution size-exclusion chromatography. The neutral and acidic sugar composition was determined by gas chromatography. The MS spectra of the oligosaccharides were performed on an AccuTOF mass spectrometer. Molar-mass distributions were determined by coupling size exclusion chromatography with a multi-angle light scattering device (MALLS) and a differential refractive index detector. Results showed significant differences in the oligosaccharidic fraction from Cabernet Sauvignon, Syrah and Monastrell wines. This study shows the influence that the grape variety seems have on the quantity, composition and structure of oligosaccharides in the finished wine. To our knowledge, this is the first report to research the oligosaccharides composition of Cabernet Sauvignon, Syrah and Monastrell wines. [ABSTRACT FROM AUTHOR]

The effect of high levels of the polysaccharide Saccharomyces cerevisiae yeast strain (HPS) and another conventional yeast strain (FERM) on the polysaccharide and phenolic composition of Syrah red wines during alcoholic fermentation and subsequent aging on lees, with or without oak wood chips, and on inactive dry yeast was investigated. The HPS yeast released higher amounts of polysaccharides during alcoholic fermentation than FERM yeast (485 g L −1 and 403 g L −1 , respectively) and after the aging period (516 g L −1 and 500 g L −1 , respectively). The different aging techniques increased the polysaccharide concentration; the concentration was dependent on the aging technique applied. The interaction of the polysaccharides with the phenolic compounds depended on the yeast strain, aging technique, aging period and compound analysed. The HPS wines exhibited better sensory characteristics than the FERM wines after alcoholic fermentation; however, during the aging period, it was difficult to determine which technique produced the best wine due to the interactions of aging technique, aging period and sensory attribute evaluated. [ABSTRACT FROM AUTHOR]

• Grape and wine quality varied from different cluster growing spatial positions. • Microclimate and vine growth of different positions lead to the heterogeneity. • Light promotes the accumulation of flavonols and 3′-hydroxylated anthocyanins. • Wines made from upper clusters had higher alcohol degree and lightness. • Lower clusters give the wine a higher total acidity and red color component. The fan training system with multiple trunks (F-MT) is widely used in the northern China winegrape region with high yield and convenience for burying soil to prevent winter cold. However, the wide distribution of clusters under F-MT usually leads to variations in berry compositions. In two consecutive years, clusters from different spatial positions were collected to determine the phenolic composition in grapes and resultant wines by HPLC-QqQ-MS/MS. Results showed that light exposure promotes the accumulation of flavonols and 3′-hydroxylated anthocyanins in berries. Wines made from upper clusters had higher alcohol degree, lightness, monomeric anthocyanins and flavonols, whereas wines made from lower clusters had relatively higher total acidity, red color component, polymeric anthocyanin and total flavanols. Most of the wine parameters were also significantly affected by vintage. In conclusion, the quality of grapes and wines varied from different cluster positions, graded harvesting helps to maximize the characteristics of grape berries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Monitoring of tannins evolution during ageing through oxidation markers by LC-MS2. • Estimation of accelerated oxidation impact versus natural evolution in enology. • Markers of the second oxidation level of tannins increase during the ageing. • In accelerated oxidation wine the first oxidation level markers are similar to the 2014. • The second oxidation level in forced wine ageing indicating a more advanced state. 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. [ABSTRACT FROM AUTHOR]

• B-type procyanidin dimer and new catechin dimeric oxidation products were analyzed. • Depending on dimer type (B, C O C or C C), specific mass fragments were obtained. • 3 oxidation markers were identified in seeds with an increasing trend with ripening. • 3 oxidation markers were identified in wines with a decreasing trend with ageing. 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 C O C 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. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two young Greek red wines (Syrah and Cabernet) were artificially aged. [•] Eleven different wood chips were used (two of them were used for the first time). [•] Content of resveratrol and catechin, color and sensory properties were improved. [Copyright &y& Elsevier]

Abstract: Syrah and Chardonnay grapevines were treated with an oak extract in order to determine the effect on glycosidic aroma precursors. Grapevines were treated at three different timings of the veraison (treatment 1, 2 and 3). Aglycons were obtained by enzymatic hydrolysis, and these were identified and quantified by means of gas chromatography–mass spectrometry (GC–MS). Results suggest that after the applications the majority of compounds from the oak extract were assimilated and stored as glycosidic forms in both cultivars. Also, other compounds not present in the extract were affected, with a different behaviour observed depending on the timing of application and the variety. In general, C6 compounds, alcohols, terpenes, phenols and C13-norisoprenoids in Syrah showed a decrease and in Chardonnay an increase. Thus, this study proved a change in the glycosidic aroma profile in grapes after the oak application, so these treated grapes could produce wines with different aromatic quality. [Copyright &y& Elsevier]

Abstract: The vinification technique called pre-fermentative cold maceration is used to enhance the anthocyans diffusion from the skins to the must, increasing the pigments extraction. For using this technique the application of low temperatures is needed. In this study, two different refrigerating methods (dry ice and cooling of grapes) have been assessed regarding the colour and the phenolic composition of the Syrah wines elaborated by applying pre-fermentative cold maceration. Results showed more intense and stable colours when grapes were previously refrigerated in cold-storage rooms, which showed higher values of chroma and more red-bluish hues. As regards phenolic composition, the cold maceration technique used yields to significant differences among the levels of phenolics, having higher levels of anthocyanins and some non-coloured phenols as flavonols in PR wines. Regarding the colour-composition relationships, it has been highlighted the importance of the co-pigments such as flavonols and cinnamic acids for classify the two groups of samples. [Copyright &y& Elsevier]

[Display omitted] • Effects of tebuconazole on wine quality were investigated at enantiomeric level. • The influence of the enantiomers was different for ML and CS wine components. • HS-SPME-GC-MS and GC-IMS were used to analyze the volatile flavor compounds. • Changes in wine components led to changes in wine flavor and appearance. • The racemate and separate tebuconazole enantiomers affect wine quality differently. The impact of chiral tebuconazole on the flavor and appearance of Merlot and Cabernet Sauvignon wines were systematically studied. Gas chromatography-ion mobility spectrometry and headspace-solid phase microextraction coupled with gas chromatography mass spectrometry qualitatively and quantitatively identified the flavor components, and a photographic colorimeter was used for color attribute analysis. Tebuconazole enantiomers had different effects on the flavor and appearance of young wines, especially R -tebuconazole. The flavor differences were mainly manifested in fruity and floral characteristics of the wine due to changes in the concentrations of acids, alcohols, and esters; R -tebuconazole alters the concentrations of key flavor compounds to the greatest extent. Tebuconazole treatment changes the color of young wines, with the final red shade of wine being control group > rac -tebuconazole ≥ S -tebuconazole > R -tebuconazole. Since chiral tebuconazole negatively alters wine, grapes treated with chiral pesticides should be subject to stricter quality control during processing. [ABSTRACT FROM AUTHOR]

• Accentuated cut edges (ACE) technique was applied to Shiraz winemaking. • Thiols, thiol precursors and other volatiles were compared to conventional crushing. • ACE had no effect on thiol precursors in must but concentrations were lower in wine. • Shorter skin contact time significantly increased thiol concentration in wine. • Treatment interaction impacted acetates, higher alcohols, fatty acids, isoprenoids. Varietal thiols are important wine aroma compounds that are generally less abundant in red wines. Accentuated cut edges (ACE), known for accelerating phenolic extraction, was applied to Shiraz winemaking and compared with conventional crushing (NOACE) to examine the effects on varietal thiol precursor extraction and thiol formation. Water addition to grape must and skin contact time (SCT) during fermentation were also assessed. Although there was no difference for precursors in the must, ACE significantly decreased 3- S -glutathionylhexan-1-ol concentration during fermentation. 3-Sulfanylhexan-1-ol and ethyl esters were significantly influenced by crushing method and/or SCT, with NOACE or shorter SCT yielding higher concentrations. Acetates, higher alcohols, fatty acids, and isoprenoids differed according to the interaction of crushing method and SCT, with ACE and shorter SCT significantly enhancing all groups except acetates. Volatiles in Sauvignon blanc and Pinot noir wines produced at commercial scale with ACE were briefly evaluated, suggesting an impact of grape variety. [ABSTRACT FROM AUTHOR]

• Comprehensive Microarray Polymer Profiling was used to directly profile skins and pulp of Shiraz berries. • The skin was rich in pectins and xyloglucans, the pulp tissues were mainly composed of extensin glycoproteins. • Overripe berries, particularly those from the warmer region site, revealed degradation of their pectin and extensin epitopes. Shiraz is a widely planted cultivar in many of the world's top wine regions where it is used for the production of top-quality single varietal or blended red wines. Cell wall changes during grape ripening and over-ripening have been investigated, particularly in the context of understanding berry deconstruction thereby facilitating the release of favorable compounds during winemaking. However, no information is available on cell wall changes during berry shrinkage in Shiraz. Glycan microarray technology was used to directly profile Shiraz berries for cell wall polysaccharide and glycoprotein epitopes. Skins and pulp tissues were profiled separately and revealed that whereas the skin was rich in pectins and xyloglucans, the pulp tissues were mainly composed of extensin glycoproteins. Overripe (26–28°B) berries, particularly those from the warmer region site, revealed degradation of their pectin and extensin epitopes. [ABSTRACT FROM AUTHOR]

• Five Lachancea thermotolerans (LT) co-inocula were trialled in Merlot fermentations. • Compositional modulations of wines depended on both LT strain and inoculation regime. • LT wines had similar or lower pH/ethanol than Saccharomyces cerevisiae (SC) wines. • Ethyl lactate was up to thirty-fold higher in some LT wines than in the SC control. • Medium chain fatty acids and their ethyl esters were highest in the SC monoculture. Wines from warm(ing) climates often contain excessive ethanol but lack acidity. The yeast Lachancea thermotolerans can ameliorate such wines due to partial conversion of sugars to lactic acid during alcoholic fermentation. This study compared the performance of five L. thermotolerans strains in two inoculation modalities (sequential and co-inoculation) to Saccharomyces cerevisiae and un-inoculated treatments in high sugar/low acidity Merlot fermentations. The pH and ethanol levels in mixed-culture dry wines were either comparable, or significantly lower than in controls (decrease of up to 0.5 units and 0.90% v/v, respectively). The analysis of volatile compounds revealed marked differences in major flavour-active yeast metabolites, including up to a thirty-fold increase in ethyl lactate in certain L. thermotolerans modalities. The wines significantly differed in acidity perception, alongside 18 other sensory attributes. Together, these results highlight the potential of some L. thermotolerans strains to produce 'fresher' wines with lower ethanol content and improved flavour/balance. [ABSTRACT FROM AUTHOR]

• Study considers natural and off-vine matured seeds as sources of copigments. • Adding seeds leads to increase phenolic composition and improve wine color. • Adding overripe-seeds exerts higher quality and stability of color than ripe-seeds. • In addition, the improving effect of overripe seeds kept longer over the time. The post-fermentative double addition of Pedro Ximénez cv seeds obtained from natural matured grapes (ripe seeds, RS) and postharvest sun-dried grapes (overripe seeds, OS) were studied as sustainable enological alternatives to conventional vinification (CW) to improve the stability of Syrah wines produced in a warm climate. The phenolic composition was assessed by rapid resolution liquid chromatography, copigmentation/polymerization processes by spectrophotometry, and color quality and stability by Differential Colorimetry. OSW and RSW wines enriched their total phenolic content, being the effect more pronounced with overripe seeds (by 23% versus 10%). OSW differences were found for gallic acid, monomeric flavan-3-ols, and procyanidins compared to CW, and for (+)-catechin, procyanidin B2-3- O -gallate and the tetramer to RSW. Phenolic changes were related to higher color intensity in seed-added wines. OSW having higher percentage of polymeric pigments maintained for longer time the chromatic improvement, being visually darker and more intense than final CW and RSW. [ABSTRACT FROM AUTHOR]

• Commercial proteins and grape seed protein were assessed as fining agents. • The study considered two different stage of vinification of warm climate red wine. • Fining agents showed different impact on phenolics and color of red wine. • Differences were also depending on the age of the wine. • Potato and grape seed proteins induced lower color changes regarding control wines. Currently, the wine industry has an increasing interest in developing alternative solutions to traditional animal proteins fining agents. In this study, the impact of different protein fining agents on the turbidity, phenolic composition and color of 2-month and 12-month Syrah red wines was assessed. Wines fined with egg albumin and plant-based proteins from potato, pea, and grape seed as recent alternative, were compared to unfined control wines. Changes on turbidity, phenolic composition and color (by Differential Colorimetry) showed that animal and plant proteins differed in their clarifying efficiency and ability to interact with colorless phenolics and anthocyanins, depending on the age of wine, with important consequences on color quality and stability. Plant proteins showed lower effectiveness to reduce wine turbidity than egg albumin but modified in different way the phenolic composition, inducing lower color differences with respect to control wine and similar stability, especially potato and grape seed proteins. [ABSTRACT FROM AUTHOR]

• Maceration techniques improved extraction of compounds from red grape skin. • Microwave maceration due to high efficiency of polyphenolic compounds extraction. • Wine-making process affect the color of the wine and its antioxidant activity. This study present the effects of different pre-treatment maceration techniques (microwave, thermo-maceration, and enzymatic treatment) on the content of phenolic compounds (by UPLC–PDA) and their redox potential by cyclic voltammetry (CV), antioxidant capacity (ABTS radical cation decolorization assay and FRAP as Ferric Reducing Ability of Plasma), and other basic chemical properties of red wine made from cv. Dornfelder. The pre-treatment maceration technique significantly (p < 0.05) affected the content of total phenolics in Dornfelder must (freshly crushed grapes), with particularly high amounts in the must pre-treated by microwaves (4344.0 mg/100 mL), and the lowest in the must pre-treatment by thermo-maceration (2979.8 mg/100 mL). A positive correlation was found between the content of total phenolics and antioxidant activity (R = 0.69 and 0.52 by ABTS and FRAP assay, respectively) and individual groups of polyphenols (for ABTS assay with anthocyanins, flavonols, flavan-3-ols, respectively R = 0.60, 0.64 and 0.66, while for FRAP method only for anthocyanins R = 0.79). The highest antioxidant activity was also determined for the variant with microwave pre-treatment (must 3.31 mM and 3.05 mM Trolox/100 mL for ABTS and FRAP assay, respectively). Following the fermentation and maturation, the amount of polyphenols decreased. No thermal pre-treatment maceration methods gave lighter or redder must. After winemaking process all the samples were characterized by less red and more yellow shade. [ABSTRACT FROM AUTHOR]

• Anthocyanin derivatives' evolution pattern during wine aging was elucidated. • Color contribution of anthocyanin derivatives in various aging stage was clarified. • Pinotin, A-v-F and vitisin A contribute to wine prolonged aging color greatly. • Machine learning methods showed good predictive performance on wine aging stage. Anthocyanin derivatives and chromatic characteristics of 234 different-vintage red wine were investigated based on a targeted HPLC-MS/MS and CIELAB approach. The K-means cluster analysis showed that the evolution pattern varies amongst anthocyanin derivative classes. Their stabilities are: pinotins > flavanyl-pyranoanthocyanins, vitisin A > monomeric anthocyanin, direct anthocyanin-flavan-3-ols condensation products > vitisin B, anthocyanin ethyl-linked flavan-3-ols products. The proportion of most pyranoanthocyanins becomes more significant among all detected anthocyanin derivatives during wine aging, whereas flavanols-related anthocyanin derivatives (except for flavanyl-pyranoanthocyanins) decreased drastically. PLSR showed that aging tawny characteristics is related to pyranoanthocyanins except for vitisin B, especially pinotins, whereas monomeric anthocyanins and flavanol-related derivates (except for flavanyl-pyranoanthocyanins) contribute to red violet color. But aging color density is more associated with the content of vitisin A and flavanyl-pyranoanthocyanins. Two predictive models based on random forest and support vector machine modeling showed good performance in predicting the extent of wine aging. [ABSTRACT FROM AUTHOR]

• Brazilian red wines from São Francisco valley were studied. • Classification of geographic origin, winemaker, and grape type were achieved. • An Eco-friendly methodology based on color histograms was applied. • PCA-LDA, PLS-DA and SPA-LDA were employed as multivariate classifiers. • Good accuracy, sensitivity, and specificity were obtained. This work proposes the development of a simple, fast, and inexpensive methodology based on color histograms (obtained from digital images), and supervised pattern recognition techniques to classify red wines produced in the São Francisco Valley (SFV) region to trace geographic origin, winemaker, and grape variety. PCA-LDA coupled with HSI histograms correctly differentiated all of the SFV samples from the other geographic regions in the test set; SPA-LDA selecting just 10 variables in the Grayscale + HSI histogram achieved 100% accuracy in the test set when classifying three different SFV winemakers. Regarding the three grape varieties, SPA-LDA selected 15 variables in the RGB histogram to obtain the best result, misclassifying only 2 samples in the test set. Pairwise grape variety classification was also performed with only 1 misclassification. Besides following the principles of Green Chemistry, the proposed methodology is a suitable analytical tool; for tracing origins, grape type, and even (SFV) winemakers. [ABSTRACT FROM AUTHOR]

• Pre-fermentative juice substitution was performed for Cabernet Sauvignon and Shiraz. • Volatile and non-volatile compounds were analysed and sensory attributes were rated. • Shiraz colour and phenolic profiles were negatively impacted by juice substitution. • Sensory profiles of the wines differed depending on the substitution treatment. • An earlier harvest date could still be preferable for managing wine alcohol levels. Pre-fermentative juice substitution with water or early harvest wine has the potential to produce lower alcohol wines without critically modifying colour or tannin properties and only marginally changing volatile and sensory profiles. Whether this approach is suited to producing lower alcohol wines in the absence of excessive grape ripeness remained to be determined. The current study extends on pre-fermentative approaches to alcohol management under milder grape ripening conditions and builds on an existing study with McLaren Vale Cabernet Sauvignon fruit, allowing for a direct comparison under two distinct vintage conditions. Given its importance to Australia, Shiraz was also included and underwent the same consecutive harvest and juice substitution treatments. Cultivar-dependent implications on wine chemical properties were apparent and declines in wine colour and tannin were particularly evident in Shiraz wines, although impacts on overall wine quality and sensory parameters were minor when adjusting musts within the limit of 13.5 °Baumé. [ABSTRACT FROM AUTHOR]

• 19 °Brix was an appropriate maturation to obtain a higher number of pleasant Syrah wine volatiles. • 10 days of maceration was a promising condition to produce Syrah wines with positive odor impact. • GC × GC/MS allowed resolving 5 and 6 co-elutions involving 10 and 12 important Syrah wine volatiles. • GC × GC/MS, GC-O & GC/MS were essential for characterizing Syrah wine volatiles and their odor impact. The influence of different combinations of Syrah grape maturation degree (19, 21 and 23 °Brix) and maceration times (10, 20 and 30 days) on the volatile profile and aroma potential was evaluated for the first time through different chromatographic platforms (GC × GC/TOFMS, GC-O-OSME, GC-FID and GC/MS). GC × GC/TOFMS analyses resulted in 145 identified compounds and among these 29 were determined to be the most important for wine differentiation. The aroma compounds allowed the discrimination of Syrah wines made with grapes macerated for a shorter time (ten days) due to the higher levels of volatile compounds. The evaluation of these wines through GC-O-OSME together with GC-FID, MS resulted in the designation of 19 °Brix as the most appropriate grape maturation degree to obtain a greater number of volatiles with pleasant odor and higher intensity and persistence. GC × GC/TOFMS allowed five and six co-elutions to be resolved, involving, respectively, ten and twelve important wine compounds. [ABSTRACT FROM AUTHOR]

Changes in the principal phenolic compounds and metal content during the vinification process and storage under modified atmosphere (50% N2, 50% CO2) of Merlot and Syrah wines, from grapes cultivated in Greece, have been investigated. Comparing the variation of metals at maceration process, with the variation of monomeric anthocyanins and flavonols, an inverse relationship was noticed, that can be attributed to complexing reactions of polyphenols with particular trace elements. Cu decreased rapidly, whereas a similar behavior that could be expected for Fe and Mn was not confirmed. Differences in the profile of anthocyanins and flavonols in the fresh Merlot and Syrah wines are reported. During 1 year of storage monomeric anthocyanins declined almost tenfold, probably due to polymerization reactions and copigmentation. Also, a decrease in flavonol glycosides and increase in the respective aglycones was observed, attributed to enzymatic hydrolysis. The concentration of total phenols and all metals remained practically constant., (Copyright © 2015 Elsevier Ltd. All rights reserved.)