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.     

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.     

Effect of aging in new oak, one-year-used oak, chestnut barrels and bottle on color, phenolics and gustative profile of three monovarietal red wines

This study provides specific information about the influence of storage in bottle and in 225-L barrels made from oak (new and used for 1 year) and chestnut wood on color indexes, spectrophotometric evaluable polyphenols, anthocyanins, phenolic acids and gustative attributes of three monovarietal red wines (Piedirosso, Cabernet Sauvignon and Merlot). The results of the analysis of variance show that wood type has a significant influence on chromatic characteristics, on vanilline reactive flavans, on low molecular weight phenolics and on astringency of wines. The effect depends on the type of wine. Therefore, both traditional and alternative wood containers could be used as an instrument to regulate the polymerization, oxidation and copigmentation reaction of wine phenolics and the sensory properties of red wine. The maturation in chestnut wood could be an interesting challenge to widen the supply of red wines maturated in wood, but its use needs more care than oak.     

Statistical interpretation of the color parameters of red wines in function of their phenolic composition during aging in bottle

The relationships between the color parameters (colorimetric indexes and CIELAB variables) and the phenolic components (anthocyanins, pyranoanthocyanins, hydroxybenzoic and hydroxycinnamic acids, flavanols and flavonols) of young red wines from Vitis vinifera L. cv. Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000, Navarra, Spain), have been investigated during 26 months of wine aging in bottle (a period embracing their commercial life), through the application of different statistical analysis (principal component, correlation and polynomial regression). The results of the principal component analysis first indicated that for each variety a high degree of interrelation existed between the color parameters and the anthocyanin pigments. Moreover, it was found that for each variety the color parameters were correlated with the anthocyanins during aging in bottle. Finally, by the application of polynomial regression analysis, both anthocyanins (simple glucosides and acetyl-glucosides) and pyranoanthocyanins (anthocyanin-pyruvic acid adducts) were selected as the variables that best described the different color parameters during aging in bottle. However, differences were found between varieties in relation to the type of anthocyanin pigment selected for describing each color parameter, finally indicating the importance of the grape variety factor in the definition of the wine chromatic characteristics.     

Identification of 5-hydroxymethyl-2-furfural (5-HMF) in Cava sparkling wines by LC-DAD-MS/MS and NMR spectrometry

The aim of this study was to elucidate the structure of a potential ageing marker for Cava sparkling wine. In order to clarify the structure of this compound, NMR spectroscopy and hyphenated UHPLC-DAD-MS/MS techniques were used. We identified the hitherto unknown compound as 5-hydroxymethyl-2-furfuraldehyde (5-HMF). This is the first time that this compound has been reported in sparkling wines. A survey, based on the analysis of 80 commercial sparkling wines, showed that 5-HMF is present between 0.25 and 12.81 mg/L, and is compared with those reported for other types of wine. Hypothetical origin of 5-HMF in Cava sparkling wine is discussed.     

Fractionation and partial characterization of protein fractions present at different stages of the production of sparkling wines

Soluble proteins from sparkling wines (var. Chardonnay) manufactured industrially following the Champenoise method were analysed by analytical anion-exchange FPLC (fast protein liquid chromatography). Samples of the must, the unfined wine, the fined wine and the sparkling wines after 3, 6, 9, 12, 15 and 18 months of ageing with yeast lees were taken. Eight main must protein fractions were collected and characterized by isoelectric focusing and capillary electrophoresis. Six fractions consisted of proteins with isoelectric points (pIs) from 4.27 to 3.04. Two fractions, according to their UV spectra, seemed to contain phenolic compounds. A comparison of FPLC profiles of the must, the unfined wine and the fined wine indicated that both fermentation and stabilization processes decrease the concentration of those proteins with less affinity for the anion-exchange column and with a higher pI. No changes in the protein profiles of sparkling wines were observed during the first 18 months of ageing with yeast..     

Evolution of the phenolic content of red wines from Vitis vinifera L. during ageing in bottle

The evolution of the phenolic content, as measured by spectrophotometric methodologies [total polyphenols (TP), low-polymerized polyphenols (LPP), total anthocyanins (TA), catechins (CAT), proanthocyanidins (PRO) and o-diphenols (OD)], was studied in young red wines from Vitis vinifera L. cv Tempranillo, Graciano and Cabernet Sauvignon during 26 months of ageing in bottle. Although the wines showed differences in their initial phenolic profiles, the evolution trend of the different families of phenolic compounds was similar in the wines from the three grape varieties. TA markedly decreased during ageing in bottle (43% for Tempranillo, 65% for Graciano and 66% for Cabernet Sauvignon), following a first-order kinetic. Calculation of the kinetic parameters revealed that the disappearance rate of TA was 2-fold lower for Tempranillo wine than for Graciano and Cabernet Sauvignon wines, which exhibited similar kinetics. This decrease in TA (due to the disappearance of monomeric anthocyanins), together with a increase registered in CAT and PRO (due to the cleavage of proanthocyanidins and their structural tranformations), was consistent with a decrease in LPP, suggesting the occurrence of condensation reactions during ageing in bottle. The evolution trends observed for TP and OD during ageing in bottle were the results of changes in the different groups of phenolic compounds involved in both determinations. Global phenolic determinations, usually performed in wineries, provided useful information in relation to the evolution of wine polyphenols during ageing in bottle.     

Sensory and chemical effects of two alternatives of prefermentative cold soak in Malbec wines during winemaking and bottle ageing

Two alternatives of cold soak (CS), traditional external refrigeration (CS‐T) and use of solid CO₂ (CS‐DI), were evaluated in Malbec wines and contrasted against a control (C) during winemaking and up to 24 months of bottle ageing. Sugar consumption up to 5 g L day^‐1 was observed in CS‐T during the CS period. Both the viability of the population of Saccharomyces and non‐Saccharomyces were maintained during CS. CS‐T was detrimental for the anthocyanin and phenolic content and caused a reduction of absorbance in the visible spectrum of the wines relative to C and CS‐DI. CS‐DI had an early positive effect in the anthocyanin content and chromatic properties, but this effect subsided after 6 months of bottle ageing relative to C. From a sensory standpoint, CS‐T had the lowest colour saturation and a marked acetaldehyde character. CS‐DI wines were the most saturated in colour at press and early ageing, whereas a balsamic‐like aroma developed during bottle ageing. C wines were characterised by red fruits aroma, reduction and astringency early during winemaking, but a decrease in astringency and the reduction character occurred during bottle ageing.     

Biotechnologies in sparkling wine production. Interesting approaches for quality improvement: A review

Sparkling wines are produced by a secondary fermentation of a base wine followed by a prolonged ageing in contact with lees. In the traditional method, the refermentation takes place in the same bottle used for market distribution. The autolysis of yeasts occurs during the ageing of sparkling wines, thus causing the release of many parietal and cytoplasmic compounds which have a great influence on sparkling wine’s quality. The modern technologies for the production of sparkling wine are very different from the one developed by Abbot Dom Pierre Pérignon in the 17th century. Over the years, many advances have been made, this paper aims at reviewing the recent knowledge in the application of biotechnologies for the improvement of sparkling wine’s quality, in particular the factors affecting foaming properties and sensory qualities. Future perspectives and trends are also considered.     

Phenolic compounds and antioxidative properties of selected wines from the northeast of Thailand

The phenolic contents and antioxidative properties of selected wines, produced in the northeast of Thailand, were evaluated and compared, particularly those produced at Suranaree University of Technology (SUT) Farm as a case study. Nine wine varieties were used to evaluate their total phenolic content (TPC) by Folin–Ciocalteu method, free radical scavenging efficacy by DPPH method and reducing power by ferric reducing-antioxidant power (FRAP) method. The red wines had significantly higher (p < 0.05) amounts of total phenols, flavonoids and antioxidant activities (AA) compared to white wines. Capillary electrophoresis (CE) was used as a powerful and high performing tool for analysis of principal phenolic compounds in the wines. t-Resveratrol was found in Shiraz, Zinfandel and blended wine varieties. (+)-Catechin was found in all wine varieties, except in Chasselar Dore. (+)-Catechin was present in wines at a higher level than (−)-epicatechin. In red wine, gallic acid was the dominant phenolic acid found.     

Classification of red and white wines by denomination of origin according to phenolic composition and colour characteristics and correlation with standard parameters

The two main phenolic compounds, namely anthocyanins and tannins, and some chromatic characteristics have been determined in 437 samples of red and white wines from northwest of Spain, which were commercialised in two consecutive years (2005 and 2006). The variation range for total polyphenol index (TPI) was 4.1–16.6 and 27.8–91.9 in white and red wines, respectively. Standard parameters were also investigated. The classification successful by Denominations of Origin was near 50% for both red and white wines. Statistical correlations among standard and colour parameters were established to find a simple methodology usually used in winery that permits to provide more complete information for the oenologist. So, a significant correlation was found for TPI or chromatic intensity and volume mass in red wines (0.547–0.583, P < 0.01), while tonality can be estimated from pH (0.601, P < 0.01). No lineal relationship was found in white wines.     

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.     

Effect of high pressure treatments on the physicochemical properties of a sulphur dioxide-free red wine

The application of high hydrostatic pressure (HHP) in winemaking for substitution of the use of sulphur dioxide is still at a very early stage of development, since knowledge about the effect on physicochemical and sensorial characteristics of the wine during storage is very scarce. In this work, the evolution of colour, antioxidant activity and total phenolic compounds of SO₂-free red wines treated by HHP and aged in bottles was followed for 12 months. The pressurised wines were compared with wine samples prepared with addition of 40 ppm of SO₂ and without any of these two treatments. After 12 months, the pressurised wines presented higher values of CIELab parameters (a^∗, b^∗, and L^∗) and a lower monomeric anthocyanin content (45–61%) when compared to the unpressurised ones. The pressurised wines showed also a better global sensorial assessment, with the pressure treatments imparting aged-like characteristics to the wines. The wine deposits of pressurised wines had higher total phenolic content, namely proanthocyanidins (3- to 10-fold). The results demonstrate that HHP can influence long term red wine physicochemical and sensorial characteristics, hypothesised to be due to an increase of condensation reactions of phenolic compounds, forming compounds with higher degree of polymerisation that became insoluble in wine along storage.     

A comparison of analytical methods for measuring the color components of red wines

The monomeric and polymeric pigments of 20 young red wines were analysed using most recent of the approaches available for phenolics measurements in wine, including: (i) HPLC with silica-based reversed-phase, (ii) HPLC with polymeric-based reversed-phase columns, (iii) the spectrophotometric Adams’ tannin and polymeric pigments assay, (iv) the Boulton’s copigmentation assay, and (v) the Somers’ unbleached polymeric color assay. Moreover, a modification of an existing HPLC method, i.e. the addition of SO₂ to the mobile phases, allowed the unbleached polymeric pigments to be analysed by HPLC for the first time. The wines displayed a variation in their color density at 520 nm that ranged by 10-fold, and included wines made from Pinot noir, Merlot, Cabernet sauvignon, Cabernet franc, Sangiovese, Cagnulari and Cannonau grapes. The total color of wines was an aggregate number of three components: copigmentation (8–30%), total free anthocyanins (24–35%), and polymeric pigment (35–63%). Cross-comparison between the selected method was performed and discussed. In particular, the polymeric pigments estimated by HPLC with polymeric-based reversed-phase column were in good agreement with the result of the reversed-phase C₁₈ column (R² = 0.9703) and the sum of small and large polymeric pigments estimated by the Adams’ assay (R² = 0.9511). The level of copigmentation can be almost completely described by the levels of monomeric pigments (R² = 0.9464) and not by the tannin content as has often been suggested (copigmentation vs tannin: R² = 0.4827).     

Polyphenols and colour variability of red wines made from grapes harvested at different ripeness grade

Several red wines were elaborated in order to study the influence of the grape harvesting date (degree of maturity of the grape) on their chromatic characteristics and polyphenolic contents. Wines made from two grape varieties, at three different harvesting dates and from two consecutive vintages, were selected for this study. The results showed that the harvesting date of grapes (directly correlated with the degree of maturity of the grapes), influenced the chromatic characteristics of the wines, although their polyphenolic compositions were clearly different, especially in Cabernet Sauvignon wines. In general, higher intensities of blue or violet tones were detected in wines made from the grapes collected on the second harvesting date, in which the ratios anthocyanins/proanthocyanidins and anthocyanins/(proanthocyanidins + catechins) were the lowest. These ratios are proposed as probable indicators of the aptitude for wine ageing.     

Viability of total phenol index value as quality marker of sparkling wines, “cavas”

To evaluate the viability of the A280 value for monitoring the development of cava sparkling wine during its ageing in contact with lees and its commercial shelf life, an accelerated test was applied to four types of sparkling wines obtained at industrial scale. All cava types were stored under oxygen and carbon dioxide conditions at 37 °C for 13 weeks. During the accelerated test, a positive relationship between absorbance at 280 nm (A280) and time was observed, while the main phenolic compounds decreased even under nonoxidative conditions. The increase in the phenol index value corresponded (p < 0.01) to an increase in a colourless compound. Both increases occurred mainly under nonoxidative conditions. This compound is a tentatively identified polyhydroxylate structure with a λ_max 284 nm and an accurate mass of 178.0398, which corresponds to the molecular formula, C₆H₁₀O₆. The present study found that sugars are the origin of this compound and play an important role in A280 increase under reductive conditions. The value of A280 could be a simple marker for monitoring the quality of the evolution of sparkling wine during its ageing in contact with lees and its commercial shelf life.     

Influence of winemaking techniques on the resveratrol content, total phenolic content and antioxidant potential of red wines

In this paper, the influence of winemaking techniques and cultivars on the resveratrol content, total phenolic content and antioxidant potential of red wines was studied. Wines were made from the cultivars Merlot, Cabernet Sauvignon, Pinot Noir and Prokupac. Applied winemaking technologies included thermovinification and separation of must from pomace. The analysis of trans- and cis-resveratrol in wines was performed by HPLC, while the total phenolic content and antioxidant potential was determined by spectrophotometric methods. The total resveratrol content in analysed samples ranged from 0.35 to 4.85 mg/l; Merlot wines had the highest average resveratrol content, while the lowest was found for native cultivar Prokupac. Although the resveratrol content depended on grape variety, correlation between the winemaking technology applied and the resveratrol level in wines was not observed. The total phenolic content (TPC) varied from 544.4 to 1410.4 mg/l expressed as gallic acid equivalents, and the antioxidant potential, assayed by DPPH in terms of SC₅₀ (mean scavenging concentration), ranged from 0.58 to 2.91 μl/ml. Obtained results showed that thermovinificated wine samples had higher amount of phenolic compounds. Significant negative correlation was observed (p < 0.05) between the total phenolic content and SC₅₀, but there was no significant correlation (p > 0.05) between the resveratrol content and SC₅₀ or TPC. This study could contribute to the establishment of optimal conditions for producing red wines which contain more beneficial phenolic compounds.     

Influence of the use of bentonite as a riddling agent on foam quality and protein fraction of sparkling wines (Cava)

This paper studies how the use of bentonite to facilitate the riddling process affects the foam properties and the protein fraction of sparkling wines (Cava). In all monovarietal sparkling wines (Macabeu, Xarel.lo, Parellada, Chardonnay and Pinot Noir), the addition of bentonite produced a statistically significant diminution of the Mosalux parameters (HM and HS). This depreciation of the foam quality may be attributed to the direct interaction of bentonite with wine proteins. Concretely the use of bentonite caused a diminution of more of 80% of total the soluble protein. Gel filtration by FPLC showed that bentonite particularly affected the 60 kDa and 20–30 kDa protein fraction. The high molecular fraction, on the other hand, was not affected.     

Cabernet Sauvignon wines from two different clones, characterization and evolution during bottle ageing

Phenolic compounds constitute important quality parameters of wines. Wines produced from different clones of the same grape variety show differences in relation to their chemical composition. The aim of this study was to characterize and differentiate Cabernet Sauvignon wines from two clones in relation to their chemical composition and to examine changes in the phenolic composition and antioxidant activity during wine ageing in the bottle. All wines were produced with Cabernet Sauvignon grapes, clones 685 and 169, from two vineyards, under the same microvinification conditions. The wines were characterized in relation to phenolic composition and antioxidant activity, as well as monitored over 11 months of bottle ageing. A significant difference was observed between the chemical compositions of the wines produced from clones 169 and 685, clone 169 showing the highest phenolic content while clone 685 had better color characteristics. The wines showed high antioxidant activity. Principal components and cluster analyses demonstrated separation of the wine according to the clone. In relation to wine bottle ageing, for both clones evaluated was observed a decrease in all phenolic compound, except of quercetin, and the antioxidant activity of these wines increased during storage.