Anthocyanin profile of young red wines of Tannat,Syrah and Merlot made using maceration enzymes and cold soak

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.     

Practical interventions that influence the sensory attributes of red wines related to the phenolic composition of grapes: a review

The phenolic composition of red wines is complex and intimately involved in colour, taste, mouth‐feel and aroma. There have been significant advances in knowledge of compounds with relatively simple structures, but understanding of those with more complex and probably diverse structures is challenging. A number of phenolic compounds may form temporary complexes with anthocyanins and/or be involved in reactions that lead to relatively stable coloured compounds. A wide range of phenolic compounds is implicated in the oral sensory attributes of red wines. Of particular importance are flavan‐3‐ols, including proanthocyanidins (PAs). The generally observed decline in the extractability of PAs during berry ripening is due to binding with cell wall material, which may occur within the developing berry and also from tissues brought into contact during processing. Studies have shown that exposure/reduced vigour results in an increasing proportion of skin PAs being extractable during wine making. Temperature and light influence anthocyanin with temperature probably being more important and the most sensitive stage being 1–3 weeks after véraison. Skin PAs are extracted earlier than those from seeds during wine‐making. Recent results suggest some rearrangement of skin and/or seed PAs occurs during vinification which involves the cleavage of large polymers or the aggregation of small ones. The polymeric material is particularly influential in wine astringency and is transformed by incorporation of anthocyanins into tannin‐like compounds during wine‐making and storage. Although some grape‐derived phenolic compounds contribute to the aroma of red wines, likely of greater importance are the effects of nonvolatile phenolics on the volatility of a diverse range of aroma compounds. Advances in analytical techniques are likely to provide greater insights into the structures and conformations of phenolic polymers and the role of cell wall material in relation to phenolic extraction and reaction during vinification. In relation to aroma, much more research is required to reveal the details of the interactions involving phenolics with volatile compounds. It seems likely that the ability to influence the relative extraction and subsequent reaction of skin and seed phenolics is important in the production of full colour, aromatic and long‐lived wines.     

Prediction of red wine colour and phenolic parameters from the analysis of its grape extract

Herein, the phenolic composition and colour attributes of red grapes extracts (obtained with a fast methodology) were correlated with those of their corresponding wines to predict the final quality properties of wines. The phenolic parameters were evaluated as total phenolic compounds (TPC), total anthocyanins (TA) and total condensed tannins (TCT), whereas the chromatic parameters were evaluated as colour intensity (CI), tonality (To), and the percentages of yellow, red and blue tones. All of them were determined by usual UV–Vis spectrophotometric methods. To get robust models, grapes of five red varieties were collected at three different ripening stages throughout the 2009 vintage. Good correlations between the results from grapes and wines were obtained, showing high regression coefficients and low prediction errors for TPC (R² = 0.929, RMSE = 5.99%), TA (R² = 0.953, RMSE = 7.23%) and CI (R² = 0.954, RMSE = 7.58), concluding that these wine phenolic properties can be predicted reliably from the extracts obtained with an optimised fast extraction method from grapes on the ripening controls along the maturity process.     

Effect of the dry ice maceration and oak cask fermentation on colour parameters and sensorial evaluation of Tempranillo wines

The impact of dry ice maceration (DIM) and oak cask fermentation (OCF) on characteristics of Tempranillo wines elaborated in a warm climate has been studied as an alternative procedure to traditional red winemaking (CT) to obtain highly coloured wines. Oenological and colour parameters were measured to determine the influence of these techniques on wines along the winemaking process. DIM and OCF techniques were found significantly different to CT for colour intensity and percentage of blue. Moreover, both induced easily perceptible changes in CIELAB coordinates (lower L*, higher a* and values) than CT and also affect main wine's sensory attributes (e.g. increased polyphenols extraction in DIM and to a lesser extent OCF, and therefore produced wines with higher colour than CT). Although differences tend to decrease with ageing, these practices seem feasible alternatives to improve quality characteristics of young red wines from grapes grown in warm climates.     

Influence of the elimination and addition of seeds on the colour,phenolic composition and astringency of red wine

Several winemaking techniques have been developed to eliminate seeds to prevent the release of high amounts of very astringent proanthocyanidins, especially when the grapes are unripe. However, there is no scientific information on the effects of this practice. The aim of this paper is to study how the elimination and addition of seeds influence the colour, phenolic composition and astringency of red wine. The elimination of around 80% of the seeds led to a significant decrease of colour intensity and anthocyanin concentration. The addition of seeds originated wines with a greater concentration of total anthocyanin, but did not significantly affect the wine colour. These wines also presented significantly higher levels of proanthocyanidins, a greater proportion of epicatechin-3-gallate, a lower mean degree of polymerization, and, in particular, a drastic increase in astringency. Wines obtained with the elimination of seeds, on the other hand, had exactly the opposite characteristics.     

Time course of the colour of young red wines from Vitis vinifera L. during ageing in bottle

The colour characteristics of red wines from Vitis vinifera L. cv Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000) from Navarra (Spain), was studied during 26 months of ageing in bottle through the evaluation of the wine visible spectrum and of several colorimetric indices (colour intensity, %red, %yellow, %blue, %dA and tint) and CIELAB variables (L*, C*, h, a* and b*). During ageing in bottle, the spectrum of Tempranillo wine (pH 4.3) mainly changed in the absorbance range between 420 and 500 nm, whereas Graciano (pH 3.5) and Cabernet Sauvignon (pH 3.6) wines registered a decrease in absorbance in the interval between 500 and 560 nm. The time course of the different wine colour parameters was found to fit either a second‐order polynomium or a linear model, depending on the grape variety employed. CIELAB variables could be described in terms of their colorimetric index counterparts, showing b* and h relative greater errors. Although the wine total chromatic changes in CIELAB units registered after 26 months of ageing in bottle indicated changes perceivable by the human eye (ΔE* ≥ 2.7) for the three varieties studied, Graciano and Cabernet Sauvignon wines showed a more balanced colour evolution than Tempranillo wine.     

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.     

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.     

Effect of sulphur dioxide and must extraction on colour,phenolic composition and sensory quality of red table wine

Red wines were made during 1992 from Vitis vinifera var Roriz grapes using a high and a low level of extraction and three levels of total sulphur dioxide (0, 75 and 150 mg SO₂ kg⁻¹). From this single experiment, the effects of total SO₂ and extraction on anthocyanin composition and colour were observed by HPLC, spectrophotometry and tristimulus colorimetry. High extraction produced a wine with more total pigments and total phenols than low extraction and increased the amount of organic acids extracted during fermentation. More anthocyanins were extracted with increasing SO₂ levels. On maturation, all wines lost colour and increased in brownness. Wines made without SO₂ browned more than the wines made with SO₂. The anthocyanins normally present in wines were all rapidly lost to trace levels at 24 months. Vitisin A, a more stable and highly coloured anthocyanin than malvidin 3-glucoside, showed a slower decrease in concentration than malvidin 3-glucoside and contributed significantly to the wine colour during aging. At the first analysis, the wines made without SO₂ had a higher percentage colour due to polymers than the wines made with SO₂. Polymerisation progressed during maturation, although the initial differences were maintained. Sensory analysis after 6 and 18 months storage by expert tasters revealed differences mainly related to the colour attributes, indicating that when wines are made using modern hygienic techniques, total SO₂ has a negligible effect on aroma and flavour attributes. © 1998 Society of Chemical Industry.     

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.     

Browning of white wines: correlation with antioxidant characteristics, total polyphenolic composition and flavanol content

Browning is a serious problem in relation to white wine quality, which mostly affects the sensory attributes. It is well known to be associated with polyphenol oxidation, and therefore it may be accompanied by changes in the antioxidant capacity. On the basis of this consideration, thirteen experimental white wines, vinified and stored under identical conditions, were subjected to accelerated browning, and efforts were made to distinguish compositional parameters that might be related to the extent of browning development. Further, the relation of browning with the reducing power and the antiradical activity were assessed. Regression analysis at 95% significance level indicated that the antiradical activity is likely to be exerted principally by the flavanol fraction (r² = 0.92) and to a lesser extent by total phenols (r² = 0.85), as opposed to reducing power, which is mainly affected by total phenols (r² = 0.78), suggesting that synergistic phenomena account for the overall antioxidant status of white wines. In addition, the total phenolic and flavanol concentration correlated significantly with the browning rate constants and provided strong evidence that browning development might be predominately associated with flavanol (r² = 0.84) and to a lesser extent with total phenolic (r² = 0.79) oxidation.     

Influence of grape variety and their phenolic composition on vasorelaxing activity of young red wines

Red wine has been reported to exert beneficial effects in preventing cardiovascular diseases probably due to their polyphenols constituents. The vasorelaxant capacity and phenolic composition of four monovarietal young red wines Merlot, Tempranillo, Garnacha and Cabernet-Sauvignon obtained from grapes from 2004 vintage, cultivated under the same climatic and agricultural conditions, wine-making technology and storage conditions, were determined using vascular reactivity assay in rat aortic and high-performance liquid chromatography, respectively. Primary cultures of vascular smooth muscle cells from Wistar rats were also used to evaluate their survival prevention activity as well. Every studied wine present vasorelaxation effect, but the higher value corresponds to the analyzed Merlot wine, especially rich in phenolic compounds, mainly catechins and oligomeric proanthocyanidins and anthocyanin glycosides. This study further demonstrated previous investigations about the phenolic composition of wines relation with their vasorelaxation activity.     

Effect of storage on the phenolic content,volatile composition and colour of white wines from the varieties Zalema and Colombard

Different quality attributes and chemical components of wines change during storage as a function of a series of factors. Thus, in young white wines, changes in phenolics, that lead to modifications of their colour as a result of oxidation processes, are well-known. These reactions can also alter their volatile profile giving rise to the appearance of new aromas, which in some cases are undesirable. In this study we have carried out a thorough evaluation of the changes in the colour, volatiles and phenolics of Zalema and Colombard wines during 1 year of storage under different conditions of temperature and position. The phenolics and colour were more affected than was the volatiles profile and wines kept in the cold could be clearly distinguished from the others, whilst the position of the bottles onlt slightly affected the wines during storage. Results showed that the blending of Zalema wines with Colombard wines may be an appropriate means of enhancing the acidity of the former without dramatically affecting its character.     

Effect of ripening stage of grapes on the low molecular weight phenolic compounds of red wines

Different red wines were elaborated to study the effect of the date of the grape harvest on the levels of individual low molecular weight phenolic compounds, which are chiefly responsible for the wine color. Two red grape varieties and two consecutive years were studied at three different harvesting stages of grapes, and the changes during the 18 months of wine aging (12 months in oak barrels and 6 months in the bottle) were also followed. The results showed that the wines made from grapes harvested 1 week later than the usual date generally had higher contents of some simple phenols, which can act as cofactors that can maintain the color intensity and violet tonalities in aged wines. Besides, these wines had lower levels of caftaric and coutaric acids, which are two of the main substrates for oxidation and browning processes.     

Influence of the refrigeration technique on the colour and phenolic composition of syrah red wines obtained by pre-fermentative cold maceration

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.     

Changes in phenolic compounds and colour in pale Sherry wines subjected to fining treatments

 Changes in the concentrations of hydroxybenzoic acids, hydroxycinnamic acids and their esters, monomeric and dimeric derivatives of flavan-3-ol, and flavonols, as well as in the UV-visible absorbances of pale Sherry wines were studied. The wines were subjected to four different fining treatments: casein + bentonite, casein + bentonite + activated charcoal, casein + bentonite + polyvinylpyrrolidone (PVPP) and casein + bentonite + Riduxhigh. Based on the results, the treatments including activated charcoal and PVPP were the most effective at decreasing the overall concentration phenolic compounds, with no significant difference between them. Likewise, these treatments provided the best results in relation to wine colour in the visible spectral region, and particularly at 420 nm, at which wavelength browning compounds are usually measured. Received: 24 March 1997 / Revised version: 11 June 1997     

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.     

Changes in phenolic compounds and colour in pale Sherry wines subjected to fining treatments

 Changes in the concentrations of hydroxybenzoic acids, hydroxycinnamic acids and their esters, monomeric and dimeric derivatives of flavan-3-ol, and flavonols, as well as in the UV-visible absorbances of pale Sherry wines were studied. The wines were subjected to four different fining treatments: casein + bentonite, casein + bentonite + activated charcoal, casein + bentonite + polyvinylpyrrolidone (PVPP) and casein + bentonite + Riduxhigh. Based on the results, the treatments including activated charcoal and PVPP were the most effective at decreasing the overall concentration phenolic compounds, with no significant difference between them. Likewise, these treatments provided the best results in relation to wine colour in the visible spectral region, and particularly at 420 nm, at which wavelength browning compounds are usually measured. Received: 24 March 1997 / Revised version: 11 June 1997