The impact of oxygen exposure before and after bottling on the polyphenolic composition of red wines

The impact of moderate oxygen exposure after bottling on wine phenolic composition and colour properties has been investigated on four Grenache red wines showing high and low phenolic contents, obtained by flash release (FR) and traditional soaking (Trad), respectively, and processed with (Mox, 4.6 mg l⁻¹ O₂) or without (noMox) micro-oxygenation. Four oxygen transfer rate (OTR) conditions (0.8, 1.9, 8.0, and 11.9 μl oxygen/bottle/day) were ensured by using synthetic closures with controlled oxygen permeability and storage under controlled atmosphere. Wine phenolic composition and colour were monitored by triplicate analysis of bottles sampled at bottling (T0) and after 5 and 10 months of ageing. Phenolic composition was determined by reverse-phase HPLC-DAD–MS analysis, performed directly on the wines and after phloroglucinolysis for proanthocyanidins. Colour was evaluated by UV–visible spectrophotometry and tristimulus colorimetry. At T0, FR wines contained larger amounts of catechins, proanthocyanidins and hydroxycinnamic acids and slightly lower amounts of anthocyanins than the Trad wines while the Mox wines showed higher levels of some derived pigments, especially carboxypyranoanthocyanins, resulting from reactions of anthocyanins with pyruvate. During ageing, a progressive decrease of proanthocyanidins and hydroxycinnamic acid concentrations was observed, independently of OTR. In contrast, the loss of free SO₂, flavan-3-ol monomers and the conversion rate of anthocyanins to new pigments, especially into sulphite bleaching resistant pigments, increased with OTR levels. Among derived pigments, carboxypyranoanthocyanins levels increased both with micro-oxygenation and with OTR and can be considered as oxidation markers while flavan-3-ol–anthocyanin adducts were formed in larger amounts with lower oxygen exposure.     

Evolution of polyphenolic compounds in red wine from Cabernet Sauvignon grapes processed by pulsed electric fields during aging in bottle

The evolution of the Folin–Ciocalteu index, colour intensity and the principal individual polyphenols throughout 12 months of aging in bottles of red wine from Cabernet Sauvignon grapes treated and untreated by pulsed electric fields (PEF) have been compared. PEF technology allowed bottling of wines with higher Folin–Ciocalteu index, colour intensity and individual polyphenols concentrations using a shorter maceration time. For both wines, aging did not affect the colour intensity, whereas the Folin–Ciocalteu index decreased. The evolution of the principal individual polyphenols during the 12 months of storage followed a similar pattern in both wines. At the end of aging, there were no significant differences observed in the content of monomeric anthocyanins between both wines, however, the content of flavan-3-ols, flavonols and hydroxycinnamic acids and derivatives was higher in PEF treated wine. These results indicate that PEF could be a suitable technology for obtaining wines with higher phenolic content or reducing the maceration time during vinification.     

Pre-bottling use of dehydrated waste grape skins to improve colour,phenolic and aroma composition of red wines

Different dehydrated waste grape skins from the juice industry were added into aged and young red wines as an innovative way of compensating for colour loss before bottling. After addition of grape skins, colour intensity of wines increased a mean 11% and a maximum of 31% with predominance of the red component. Total polyphenols mean increase was 10% with a maximum value of 20%. Analysis of low molecular weight phenolic compounds by HPLC–DAD showed a significant (p < 0.05) content increase of the bioactive compounds gallic acid, (+)-catechin, (−)-epicatechin, and (E)-resveratrol. Anthocyanins content also increased at an average of 50 mg/l. The volatile profile of wines analysed by SBSE–GC–MS was only moderately influenced by the treatments. Mixtures of dehydrated waste grape skins were useful to improve the colour and polyphenol profile of red wines, considering them a useful tool for correcting colour loss before bottling.     

Polyphenolic compounds and antioxidant properties of selected China wines

Thirty-seven China wines, produced from different geographical origins, were examined in this study. The antioxidant activity of wines was measured by different analytical methods: oxygen radical absorbance capacity (ORAC), reducing power, 2,2-azino-di-(3-ethylbenzothialozine-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH·), hydroxyl radical-scavenger activity, superoxide radical-scavenger activity, lipid peroxidation and chelating capacity. Furthermore,total phenols, total flavonoids, total flavanols and total anthocyanins of wines were determined. As expected, the red wines had much higher phenolic content and antioxidant capacity than rosé wines or white wines. Among the red wines, Cabernet Sauvignon and Muscat Hamburg, respectively, represented the wines with the highest and lowest phenolic contents and antioxidant capacity. Among the white wines, Italian Riesling had the lowest phenolic content and antioxidant capacity. Taken together, a close relationship between phenolic contents and antioxidant capacity, for all wines, was observed.     

Effect of the winemaking technique on phenolic composition and chromatic characteristics in young red wines

The effect of six winemaking techniques (traditional, prefermentative maceration, delestage, Ganimede fermentation system, enzymes and tannins addition, or oak chip addition during alcoholic fermentation) on phenolic composition and chromatic characteristics of young red wines, elaborated from Mencía grapes grown in Galicia (northwestern Spain), was studied. The evolution of phenolic compounds from grapes to bottling and its influence on CIELab parameters were investigated. After bottling, 26 phenolic compounds were determined by high-performance liquid chromatography (HPLC), and their influence on colour stability for ageing was evaluated. Principal component analysis allowed the differentiation of the winemaking techniques studied on the base of phenolic composition, which is correlated with polymerization grade of anthocyanins. This paper can contribute to improve the knowledge about the importance of selecting the winemaking technique to elaborate high-quality young red wines and to evaluate their ability for ageing. So, the addition of enzymes and tannins seems to be the most adequate winemaking technique to elaborate red wines for ageing as it results in the formation of major number of pigmented polymers that are stable over time. Nevertheless, the prefermentative maceration, Ganimede autowinemaker and the addition of oak chips can be used for the elaboration of young red wines.     

Some interpretations of colour changes in young red wines during their conservation

During the maturation phase of red wines, extending from the end of vinification until bottling, the presence of oxygen provokes the chemical transformation of pigments, essential for ageing. Storage conditions (oak wood barrels or large tanks) should include a dissolution of oxygen of about 40 mg litre^?1 during 1 year. Under winery or cellar conditions of storage, the autoxidation of ethanol, in the presence of phenolic compounds, produces traces of acetaldehyde. Simultaneously, this acetaldehyde provokes a copolymerisation of anthocyanins and tannins; in the condensed form, the anthocyanins are more coloured than in the free form. Hence aeration provokes an increase in colour, even though concentration of anthocyanins decreases as determined by chemical analysis. As condensation reaches a certain level, the large molecules precipitate and colour decreases. The same oxidation produces an increase in the level of tannin condensation and consequently a decrease in astringency, favourable from the point of view of quality. As a whole, the rate of these condensation reactions is reduced by an excess of SO₂.     

The influence of pectolytic enzyme addition and prefermentative mash heating during the winemaking process on the phenolic composition of Okuzgozu red wine

The effects of pectolytic enzyme addition and mash heating prior to fermentation on the phenolic component of Okuzgozu red wine during the winemaking and ageing processes were investigated. In general, the highest concentration of total phenolics was found in the mash-heated wines, whereas the total flavan-3-ol and total anthocyanin contents in all of the wines, decreased notably during the winemaking and ageing processes. As determined by HPLC, hydroxycinnamic acids were the major phenolic acids in the red wines. After 6 months in the bottle, the enzyme-treated wines had lower phenolic acid concentrations than had the control and mash-heated wines, but no significant (p < 0.05) differences were found in the concentration of total phenolic acids between the control and mash-heated wines. All of the phenolic acid levels decreased with the winemaking and ageing processes whereas only gallic acid increased. The wines treated by the pectolytic enzyme addition had a lower monomeric flavan-3-ol content than had the other wines, and the amount of monomeric anthocyanins extracted did not increase with the addition of enzymes.     

Changes in phenolic composition of Tinta Miúda red wines after 2 years of ageing in bottle: effect of winemaking technologies

The major phenolic compounds (catechins, oligomeric and polymeric proanthocyanidins, and anthocyanins) in Tinta Miúda red wines made by various winemaking technologies (i.e., fermentation with carbonic maceration, fermentation with stem contact and fermentation without stem contact) were analyzed after 2 years of ageing in bottle, and compared with the data on their younger state (i.e., at the time of bottling). The concentrations of all individual phenolic compounds analyzed were significantly changed and their degradation rates (percent of decrease) were highly dependent on the winemaking technology used. The degradation of anthocyanins was, in general, more remarkable than that of catechins and proanthocyanidins. Catechins and proanthocyanidins in carbonic maceration wine appeared more stable than in skin fermentation wines, during ageing in bottle.     

Polyphenolic content of Vranec wines produced by different vinification conditions

Macedonian Vranec wines were analysed by HPLC coupled with DAD and MS detections and by spectrophotometric methods. ESI-IT MS and MS–MS methods with alternating ionisation polarity were used for identification of the phenolic compounds. Both, nonflavonoids (stilbens, hydroxybenzoic and hydroxycinnamic acids and derivatives) and flavonoids (flavonols, flavan-3-ols and anthocyanins) were detected in the samples. Vranec wines were produced under different fermentation conditions: maceration time of 3, 6 and 10 days, two doses of SO₂ (30 and 70 mg l⁻¹) and two yeasts for fermentation, in order to examine their effects on the extraction of phenolic compounds from grapes into the wine.     

Determination of phenolic compounds in wines: Influence of bottle storage of young red wines on their evolution

Various analytical methods based on the HPLC-DAD technique were used to determine 38 phenolic compounds in red wines. While anthocyanins and hydroxycinnamic acids were determined by direct injection of wine samples, hydroxybenzoic acids, catechins, procyanidins and flavonols required an analytical pretreatment involving liquid–liquid partitioning with ethyl ether followed by solid-phase extraction on C₁₈ mini-columns. The proposed analytical methods were used to establish the phenol composition of Mencía and Brancellao, two varietal young red wines, and its influence on colour stability during storage in bottles for one year. At the end of malolactic fermentation, Mencía wine was found to contain much greater amounts of anthocyan pigments than was Brancellao wine. This resulted in a higher colour density but a weaker hue in Mencía wine than in Brancellao wine. Phenolic compounds evolved similarly in both wines during storage; changes in such compounds involved a decrease in the levels of monomeric anthocyanins, phenolic acids, epicatechin and flavonols, and an increase in those of procyanidins. The absence of a relationship between the changes in colour density and monomeric anthocyanins in both wines suggests that copigmentation and polymerization with other phenolic compounds (viz. phenolic acids, catechins and/or flavonols) prevail over degradation of the pigments.     

Impact of using Trepat and Monastrell red grape varieties on the volatile and nitrogen composition during the manufacture of rosé Cava sparkling wines

The impact of using Trepat and Monastrell red grape varieties during the manufacture of rosé sparkling Cava wines on the nitrogen and volatile composition compared to a white Cava manufactured with a blend of typical white grape varieties (Xarello: Macabeo: Parellada) has been investigated. The wines were industrially manufactured in a cellar, and the concentrations of outstanding nitrogen compounds and 23 target volatile compounds belonging to different chemical classes were determined in the base wines and in the corresponding Cava wines after 9, 12, 15 and 18 months of aging on lees. After the application of multivariate statistical analysis, the results showed the large effect of the variety employed in the manufacture of Cavas compared to the changes in wine composition due to the aging time. Depending on the composition, Trepat and White Cava wines were more similar than those manufactured with the variety Monastrell. However, the sensory study showed that the two rosé Cava wines had good sensory attributes and even slightly better foam characteristics than the white ones. The sensory study highlighted for the first time the adequacy of using Monastrell red grape variety to manufacture rosé sparkling wines.     

Comparative study of phenolic compounds in Cabernet Sauvignon wines made in traditional and Ganimede fermenters

Chemical profiles of anthocyanin and non-anthocyanin phenolics of Cabernet Sauvignon wine made by two different winemaking techniques (traditional vinification and Ganimede method) were determined by high performance liquid chromatography–mass spectrometry (HPLC–MS). Particularly, effect of extraction on and subsequent stability of the phenolic compounds from the end of fermentation to bottling were investigated. The results showed that the total anthocyanin content was higher in the young wines produced in the Ganimede fermenter. The anthocyanin contents in these wines subsequently decreased significantly after two years of ageing. By contrast, the traditional vinification was slightly better than the Ganimede to yield the non-anthocyanin phenolics. This indicates that the Ganimede fermenter might be suitable for the production of brightly coloured red wines for early consumption, which could save time and labour cost for industrial production of highquality wines.     

Effects of mechanical thinning on fruit and wine composition and sensory attributes of Grenache and Tempranillo varieties (Vitis vinifera L.)

Background and Aims: Cost-effective yield control is required by the wine industry in order to reduce the existing worldwide wine surplus and to improve grape quality. The object of this study was to evaluate the chemical and sensory effects on the resulting wines of mechanical cluster thinning performed at different intensities on Grenache, and at different timings (pea size and veraison) on Tempranillo. Methods and Results: The experiments were conducted with a machine harvester in 2007 on two commercial vertical shoot-positioned vineyards in Spain's Rioja region. In both varieties, mechanical thinning was effective in yield reduction and resulted in more ripened fruit, and wines with higher alcohol and pH values, more intense colour and increased phenolic content. Regardless of the thinning intensity, sensory changes were less noticeable in Grenache than in Tempranillo wines. Of the latter, those from vines thinned during veraison were less aromatic and sour, but had increased astringency. Conclusions: Yield management through mechanical thinning induced changes to the chemical composition of fruit and wines as well as to the wines' aroma, taste and mouthfeel. The extent of the sensory implications seems to depend on several factors such as the variety and timing of thinning application. Significance of the Study: This is one of the first studies addressing the effects of mechanical thinning on the sensory properties of the resulting wine and has implications for viticultural management practices.     

The impact of closures, including screw cap with three different headspace volumes, on the composition, colour and sensory properties of a Cabernet Sauvignon wine during two years' storage

This paper presents the results from an investigation to assess the development of a Cabernet Sauvignon wine bottled with different closures including a screw cap (ROTE, roll-on-tamper-evident) and different ullage volumes (4, 16 and 64 mL of air). The wines were filled manually, sealed using commercial equipment and stored under controlled temperature and humidity conditions. The concentration of free and total SO₂, and phenolic compounds including anthocyanins, selected pigments, pigmented polymers and tannins, and colour measurements using spectral and CIELAB methods, have been determined in the wines over a two-year storage period. In addition, sensory analysis of the aroma and palate properties of the wines was performed after 6, 9, 11, 18 and 24 months' storage. The wines sealed under the screw cap with either 4 or 64 mL ullage volumes were clearly different from each other and the other treatments in the study, and these differences were seen within the first year after bottling. The wines bottled under the more commercially relevant conditions, screw cap with 16 mL headspace, synthetic closure or natural bark closure, were more similar in both composition and sensory characters, although subtle differences between different closures were evident. 'Rubbery' and 'struck flint' like aromas (generically termed reduced aroma) were detected in some of the wines in the study but were not a large or dominating character. The scores for this character were highest in the wine sealed under the screw cap with the smallest ullage volume.     

Colour and phenolic compounds in sweet red wines from Merlot and Tempranillo grapes chamber-dried under controlled conditions

Chamber drying under controlled temperature and humidity conditions of the red grape varieties Merlot and Tempranillo grown in Andalusia (Spain), and the fortification and maceration of the musts in the presence of skin from both types of grapes, to obtain sweet red wines, has been studied. Changes in colour and in monomeric and polymeric phenols during the vinification process were examined. Chamber drying increased the sugar content to about 31.4 °Brix within 48 h in Merlot grapes and 72 h in Tempranillo grapes. This drying process also causes skin rupture, facilitating the access of phenolic compounds to the pulp. The resulting musts exhibited slight browning and increased red hues, due to a high concentration of anthocyanins; maceration in the presence of grape skins for 24 h provided the best results. The end-product contained highly acceptable tannin, colour and phenolic compounds for marketing as a high quality sweet red wine, in comparison with other commercial sweet red wines.     

Varietal and geographic classification of French red wines in terms of pigments and flavonoid compounds

Thirty-four French red wines originating from six different grape varieties and three different production areas were analysed in duplicate for 15 anthocyanins, ten flavonoids and three colour parameters, F-statistics, principal component analysis and stepwise discriminant analysis were used to identify and to explain differences among samples. Clear difference between wines made from different varieties were mainly related to anthocyanin 3-acylglucosides. Malvidin and peonidin 3-acetylglucosides were found in increasing concentrations in wines made respectively from Grenache, Carignan, Cinsault, Merlot, Carbernet Sauvignon and Cabernet Franc grapes; the concentrations of peonidin and malvidin 3-p-coumarylglucosides were higher in the Cinsault wines studied. Cabernet Sauvignon and Merlot wines made near Bordeaux had a less intense colour and a higher malvidin 3-glucoside content than wines from the same varieties produced near Narbonne. Wines made from Merlot, Cabernet Sauvignon and Cabernet Franc grapes contained more catechin, epicatechin and myricetin when produced in the south than in the north (Narbonne, Bordeaux, Angers). Of the samples analysed, 96%, and all of the nine extra wines, were correctly classified according to the variety of the grapes using four anthocyanins and catechin selected by step wise discriminant analyses.     

Multivariate statistical analysis for the classification of oak-aged wines based on their chromatic characteristics

The objective of this study was to characterise oak-aged wines according to the ageing conditions by measuring colour and phenolic compounds, and to study the correlations between the studied variables to understand the relationship among them, and help to clarify some of the mechanisms involved in the modification of colour during wine ageing. The results show that the colour of aged wines can be mainly attributed to polymeric compounds and not to monomeric anthocyanins; the cluster analysis showed that the samples could be mainly separated as regards the age of the barrel. The discriminant analysis achieved a good sample separation regarding oak origin and barrel age.     

The effect of microwave assisted extraction on the isolation of anthocyanins and phenolic acids from sour cherry Marasca (Prunus cerasus var. Marasca)

The aim of this study was to evaluate the influence of microwave assisted extraction on the isolation of anthocyanins and phenolic acids from sour cherry Marasca. A general factorial design was used to study the effect of temperature (from 50 to 70 °C), irradiation time (5–12 min) and microwave power (350–500 W) on individual, total anthocyanins and individual and total phenolic acids. Optimal microwave assisted extraction conditions differed for anthocyanins and phenolic acids, especially in terms of temperature and irradiation time, so lower temperature (60 °C) and shorter time (6–9 min) was more convenient for anthocyanins extraction, while phenolic acids gave higher extraction yield at higher temperatures (70 °C) and longer irradiation time (10 min). The optimal microwave power did not differ significantly for studied compounds, ranging about 400 W. Compared to conventional extraction, microwave assisted one showed higher efficiency for all studied compounds.     

Influence of prefermentative maceration temperature on the colour and the phenolic and volatile composition of rosé wines

Prefermentative maceration for 8 h at 5, 10 and 15 °C was used to make rosé wines, and changes in their colour (colour intensity (CI), tone and CIELAB parameters), phenolic compounds (classic indices and individual compounds) and volatile compounds (major and minor) were monitored from the must stage to wines until 6 months after bottling. The 15 °C maceration temperature provided wines with the highest CI, a* and C* values, the greatest malvidin‐3‐glucoside content and the lowest alcohol and ethyl acetate levels. Only in these wines were terpenols released after 6 months in the bottle. The wines produced at 5 °C had the highest ester levels, which also remained more stable during storage. When using maceration temperature as the differentiating variable in a discriminant analysis, volatile compounds were important contributors. However, colour and phenolic compound parameters were important when sampling time was used as the differentiating variable. The best scoring wines in an informal sensory evaluation test were those subjected to 15 °C maceration, while the least appreciated were those macerated at 5 °C. Copyright © 2005 Society of Chemical Industry     

Antiproliferative effects of cherry juice and wine in Chinese hamster lung fibroblast cells and their phenolic constituents and antioxidant activities

Cherries are good sources of bioactive phenolic compounds that are widely considered to be potentially healthy. Here we investigated the protective activities of juice and wine products of tart and sweet cherries and their constituent anthocyanins (e.g., cyanidin 3-glucoside and cyanidin 3-rutinoside) against oxidative stress induced by hydrogen peroxide (H₂O₂) in Chinese hamster lung fibroblasts (V79-4). Total phenolics in the cherry juices and wines were 56.7–86.8 mg of gallic acid equivalents (GAE)/l and 79.4–149 mg GAE/l, respectively. Total anthocyanins in the cherry juices and wines were 7.9–50.1 mg of cyanidin 3-glucoside equivalents (CGE)/l and 29.6–63.4 mg CGE/l, respectively. Both cherry juices and wines exerted protective effects against oxidative stress induced by H₂O₂ on V79-4 cells and also enhanced the activities of antioxidative enzymes, such as superoxide dismutase and catalase, in a dose-dependent manner. The protection of V79-4 cells from oxidative stress by phenolics was mainly attributable to anthocyanins. The positive correlation between the protective effects against oxidative stress in V79-4 cells and the antioxidant enzyme activities was stronger for cyanidin 3-glucoside than for cyanidin 3-rutinoside.