Anthocyanins are the main pigments of young red wines. The aim of this work was to evaluate the anthocyanin composition of red wines produced by alternative procedures of winemaking and different ...grape varieties. For this purpose, wines of Tannat, Syrah and Merlot were made by traditional maceration (TM), addition of maceration enzymes (ENZ) and cold soak (CS). Syrah wines had the highest proportions of malvidin (86.0 ± 1.0) and peonidin (5.5 ± 0.4), while Tannat wines had the highest of delphinidin (6.9 ± 0.8), petunidin (13.2 ± 0.6) and nonacylated glucosides (73.6 ± 0.6). Cold soak increased the anthocyanins contents in Tannat and Merlot wines. In turn, maceration enzymes affect the anthocyanin profile and the stability of the colour of wines. Discriminant analysis of data showed significant separation of the wines of each variety as the anthocyanin profile showed the varietal fingerprint, despite the different winemaking procedures.
•Fining influence colour and composition of red wines.•Different fining agents had different incidence on colour of wines.•Bentonite had negative impact on the anthocyanin contents and wine ...colour.•Gelatin decreased significantly tannins concentrations.•Wine polyphenol composition is an indicator for a better choice of the fining agent.
This work aimed to evaluate the effect of four fining agents on the colour and pigment composition of red wines of Tannat. The wines were analysed 15days after fining and immediately after separation of sediments and bottling. Colour was evaluated by spectrophotometry and polyphenols were analysed by spectrophotometry and HPLC–DAD. The colour intensity of wine was significantly decreased by bentonite and egg albumin. The most remarkable effects on wine phenolic composition were produced by bentonite and gelatin, which significantly decreased anthocyanin and tannin concentrations, respectively. Results show that each fining agent has very different impact on the wine attributes, and their effects depended as well on the composition of the clarified wine. The use of non-traditional agents of fining, as vegetable proteins, may have less impact on the colour and anthocyanin content of red wines.
•Malvidin 3-feruloyl-glc was identified in all skin, wine and pomace samples of Tannat.•The p-coumaroyl-derivatives were poorly extracted from grape to wine.•Caffeoylated-anthocyanin synthesis would ...take place during vinification.•Methoxylated anthocyanins would be less extractable but more stable in wines.•The pomace retained methoxylated and acylated pigments which are particular stable.
The purpose of this investigation was to assess the grape pigment extraction during red-winemaking. The pigment content and profile of skin, wines and pomace of Vitis vinifera grapes with different pigment profiles Syrah, Marselan and Tannat was thoroughly studied. The p-coumaroylated anthocyanin proportions were 37% in pomace, compared to 19% in skins and just 5% in wines, highlighting their poor extraction. Di-methoxylated based anthocyanins, increased their relative contribution in pomace and wines compared to skins, indicating they were less extracted, but more stable once extracted. Remarkably, the caffeoylated anthocyanins presented significantly higher concentrations in pomace than in skins (1.9 fold on average), suggesting that their synthesis could take place during vinification. Malvidin 3-feruloyl-glucoside was found in the Tannat samples being the first evidence of an anthocyanin acylated with ferulic acid in wine. Pigment extraction was selective depending on anthocyanin B-ring substitution pattern and acylation profile.
The aim of this research was to determine the effectiveness of the substitution of grape juice of grapes with different maturation degree and prefermentative hot maceration to obtain Pinot Noir and ...Tannat red wines with lower alcohol content and pH and higher color and phenolic compound concentrations. Immature grape juice was extracted of grapes harvested in veraison and kept at 4 °C until its use. In technological maturity, the grapes harvested were destemmed, crushed and distributed in 12 containers per cultivar. Six were controls while in the other six 3 L of the original grape juice were substituted by 3 L of unripe grape juice. Next, three containers from each experimental group were traditionally macerated, while the other three were submitted to a prefermentative hot maceration (one hour at 60–70 °C). All treatments performed a fermentative maceration of 7 days. Wines produced from substituted musts had lower alcohol content (14% off) and pH (9% off) and higher titratable acidity (48% more), but no other important changes in wine components were detected. Prefermentative hot maceration increased wine color intensity (50%), total phenolic compounds (66%), total anthocyanin (42%), proanthocyanidin (65%) and polysaccharide (95%) concentrations. The joint consideration of both techniques is an interesting tool to simultaneously mitigate the problems caused by climate change with respect to the maturity of the grape and improve the color of the wine and its concentration in polysaccharides and phenolic compounds.
The flavanol composition of red wine, stemming from grape skins and seeds, is a determinant factor of its quality. It has been proposed that the wine flavanol structure depends on the grape cultivar ...but with skin-derived flavanols prevailing in traditional red winemaking from mature grapes. However, this has not been confirmed for many cultivars. This study analysed the flavanol composition in grapes, wines, and pomace of Syrah, Marselan, and Tannat,
Vitis vinifera
cultivars known for their potential to yield tannic wines. Across two vintages, 20 wines were produced through traditional winemaking. Flavanols were analysed by HPLC–MS/MS before and after acid-catalysed depolymerisation of proanthocyanidins. Grapes of different ripeness were considered as vineyard with different agronomical characteristics. Nevertheless, each cultivar exhibited a characteristic flavanol composition in both grapes and wines. Notably, all Marselan wines had high proportions of seed-derived flavanols (high proportions of monomers, dimers and low of prodelphinidins), from grapes with high skin flavanol content. In contrast, Tannat and Syrah wines had high proportions of skin-derived flavanols, irrespective of the corresponding seed flavanol levels in grapes. Flavanol extractability from skins mainly regulated wine composition, being unusually low in Marselan, rising with ripeness in Syrah, and consistently high in Tannat, masking the high seed flavanol contents of its grapes. Therefore, wines with high proportions of seed-derived flavanols can be obtained from fermentative macerations of ripe grapes. Pomaces were found to be a rich source of flavanols, primarily from seeds where they largely remain unextractable.
Summary
The anthocyanin composition of Tannat red wines obtained with four winemaking techniques was evaluated in different years. The wines were elaborated with traditional maceration (TM), cold ...pre‐fermentative maceration, delayed extraction of anthocyanins and extended maceration. Two vinifications were carried out for each technique, employing 70 kg of grapes in each one. The anthocyanin composition of wines was analysed by high‐performance liquid chromatography–diode array detection. The results confirm the fundamental role of the grape composition on the anthocyanin composition of the wines. The winemaking had an important effect on the total concentration of anthocyanins and also may modify the anthocyanic profile of wines. The wines obtained with TM had higher or similar content of anthocyanins than those elaborated with the other techniques. Canonical discriminant analysis of data showed that vintage has a greater effect on anthocyanin concentration than winemaking techniques.
Resumen
Este estudio resume los principales resultados de ensayos realizados en Uruguay con la variedad Tannat durante 25 años. Los vinos de este cultivar son emblemáticos del Uruguay. Tienen una ...gran tipicidad, con un color y composición polifenólica particulares. Se evaluaron distintas técnicas de vinificación, con el objetivo de mejorar la calidad de los vinos y mitigar los efectos del cambio climático. Las opciones evaluadas fueron: (I) empleo de enzimas de maceración, (II) maceración pre-fermentativa en frío, (III) extracción diferida de antocianos, (IV) maceración extendida, (V) extracción diferida de antocianos con maceración extendida, (VI) maceración pre-fermentativa en caliente, (VII) empleo de taninos enológicos. Los testigos de cada ensayo fueron vinos elaborados de manera tradicional (MT). La MPC fue la técnica que tuvo mayor impacto en el color y la composición fenólica de los vinos. Los contenidos de antocianos solamente fueron incrementados por la MPC y ENZ. Los contenidos de taninos poliméricos fueron incrementados muy significativamente por MPC, ME y la MPF. A su vez, los mismos tratamientos incidieron significativamente en los contenidos de taninos monoméricos. Los resultados obtenidos fueron diferentes según la técnica de elaboración, respondiendo a los objetivos procurados en cada caso, pero los efectos fueron distintos en cada año. Esto indica que el efecto de cada técnica está condicionado por el clima y su impacto en la composición de la uva.
Abstract
This study summarizes the main results of trials carried out in Uruguay with the Tannat variety for 25 years. The wines of this cultivar are emblematic of Uruguay. They have a great typicity, with a particular color and polyphenolic composition. Different vinification techniques were evaluated, with the aim to improving the quality of the wines and mitigating the effects of the climate change. The options evaluated were: (I) use of maceration enzymes, (II) cold pre-fermentative maceration, (III) delayed extraction of anthocyanins, (IV) extended maceration, (V) delayed extraction of anthocyanins with extended maceration, (VI) hot pre-fermentative maceration, (VII) use of oenological tannins. The controls of each test were wines made in the traditional way (MT). The MPC was the technique that had the greatest impact on the color and phenolic composition of the wines. Anthocyanin contents were only increased by MPC and ENZ. The polymeric tannin contents were very significantly increased by the MPC and the MPF. In turn, the same treatments had a significant impact on the monomeric tannin contents. The results obtained were different according to the winemaking technique, responding to the proposed aims, but the effects in each year were different. This indicates that the impact of each technique was strongly conditioned by the climate and its effect on the composition of the grapes.
Flavonols are a class of polyphenol compounds whose importance for wine quality has increased as their structures and properties have become better understood. Here, the acetylated and ...p-coumaroylated derivatives of the flavonol 3-O-glucosides of isorhamnetin, laricitrin and syringetin have been identified for the first time in Vitis vinifera grape skins and wines. First, the MS2 fragmentation patterns of the new flavonol derivatives showed a main signal attributable to the expected flavonol aglycone. In the p-coumaroylated derivatives, the signal corresponding to the intermediate loss of the phenolic acid was also observed. The structures of the aglycones were confirmed by their respective MS3 experiments that matched with those obtained from authentic standards of the aglycones. In addition, the fragmentation signals corresponding to the aglycone radical ions generated through homolytic cleavage assisted identification, and could support future studies of flavonoid compounds by ESI-MS. Using an HPLC-ESI-Q-ToF system, the observed m/z values of the compounds being studied were successfully matched with the expected formula. Surprisingly, just the minority methoxylated flavonol glucosides presented acylation, suggesting a high substrate specificity of the acyltransferases implicated in their synthesis. These findings show higher diversity of grape and wine flavonols. Additional studies and isolation strategies need to be followed to further characterize these metabolites as to test their presence in other grape varieties and it wines.
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•New series of acylated flavonols tentatively identified in grapes and wines.•New derivatives were found only for the minority methoxylated flavonols.•Most of putative aglycones fragmented at MS3 as the authentic standards.•Homolytic cleavage of glucosidic bond complicates MS3 spectra of putative aglycones.•The mass accuracy of the new compounds was confirmed by Q-ToF-MS.
•Maceration enzymes labelled as pigment extractors, mainly increased tannins contents.•Cold maceration increased mainly hydrosoluble and yeast derived wine phenols.•Enological tannins may increase ...wine phenolic contents not expected to be increased.•Rich flavanols wines had very low contents of them at low molecular weight level.•Tannat wines had much higher caftaric acid than reported for other grape varieties.
Low molecular weight phenols of Tannat red wines produced by Traditional Maceration (TM), Prefermentative Cold Maceration (PCM), Maceration Enzyme (ENZ) and grape-Seed Tannins additions (ST), were performed and discussed. Alternatives to TM increased wine phenolic contents but unequally, ST increased mainly smaller flavans-3-ol, PCM anthocyanins and ENZ proanthocyanidins (up to 2250mg/L). However low molecular weight flavan-3-ols remained below 9mg/L in all wines, showing that there is not necessarily a correspondence between wine richness in total tannins and flavan-3-ols contents at low molecular weight. PCM wines had particularly high concentrations of tyrosol and tryptophol, yeast metabolism derived compounds. The use of grape-seed enological tannins did not increase grape seed derived phenolic compounds such as gallic acid. Caftaric acid was found in concentrations much higher than those reported in other grape varieties. Wine phenolic content and composition was considerably affected by the winemaking procedures tested.
Cold Pre-fermentative Maceration (CPM) is an interesting winemaking technique to enhance the extraction of pigments, aroma and flavour compounds from grape skins to wine. This work aimed to evaluate ...the effect of Cold Pre-fermentative Maceration (CPM) on the composition of Tannat red wines produced in Uruguay in several vintages. For this purpose, wines elaborated by CPM were compared with control wines produced by Traditional Maceration (TM) in 4 years. Control wines (TM) were made with classical fermentation on skins. The CPM was carried out with additions of dry ice for 5 days to keep the must at 10 ºC. Wines were analysed at devatting. The impact of CPM on composition and color of wines was different in each year. Color intensity was significantly higher in CPM than control wines in 2007 and 2009 whereas the anthocyanins levels were higher in control wines every year. However, CPM wines had the highest polyphenols contents in 2007, 2009 and 2010 principally due to their catechins and proanthocyanidins contents. Anthocyanin profile was similar in the wines of each vintage, according to the varietal fingerprint. The highest contents of higher alcohols were verified in CPM wines. The Cold Pre-fermentative Maceration could have an important effect on the characteristics of Tannat red wines, although it depends strongly on the composition of the grapes of origin.
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