Influence of training system on chromatic characteristics and phenolic composition in red wines

Chromatic characteristics and phenolic composition of red wines elaborated from Sousón and Brancellao grapes (Vitis vinifera L.), whose vines were trained in cordon and Guyot systems, were determined. This comparison was possible because there were no significant differences between yields for each one. Hue was the only significantly different chromatic parameter for both training systems and cultivars. In Sousón cultivar, saturation, colour intensity and red percentage were greater for Guyot system. Sousón cultivar trained in Guyot system and Brancellao cultivar trained in cordon system were characterized by higher total anthocyanin concentration. However, greater ionization index and flavanols reagent with dimethyl aminocinemaldehyde were associated with Guyot and cordon systems, respectively, independently on cultivar. Furthermore, gentisic acid, as well as malvidin-3-glucoside, petunidin-3-acetylglucoside and malvidin-3-caffeoylglucoside in less extension, permitted to differentiate training systems in both Sousón and Brancellao cultivars. Principal component analysis was also performed for a better understanding of the differences found.     

Changes in chromatic characteristics and phenolic composition during winemaking and shelf-life of two types of red sweet sparkling wines

The Brachetto variety is the most important aromatic red grape used for the production of sweet sparkling wines in Italy. The phenolic composition and chromatic characteristics were studied in base and red sweet sparkling wines made from this variety. The present work represents the first study on sparkling wines manufactured with Brachetto grapes. The amount of pigments extracted in the base wine was low as a consequence of the necessity for short maceration time (48 h) and low alcohol content (< 3.5% v/v). The second fermentation (prise de mousse) caused a pigment content decrease, accompanied by both a color intensity decrease and a tonality increase. In terms of phenolic compounds and chromatic characteristics, lightly sparkling wines (final bottle pressure < 1.7 bar) agreed with fully sparkling wines (final bottle pressure > 3.0 bar) at the end of the second fermentation and, therefore, the chromatic quality was independent on the winemaking methodology used, excepting for lightness and color intensity.Response surface methodology was applied to predict the effect of two independent variables, namely time and temperature of storing, on the phenolic composition and chromatic properties in both lightly and fully sparkling wines. So, it is possible to evaluate the development of two types of sweet sparkling wines during their ageing in bottle and their commercial shelf-life. A central composite design (CCD) and response surface methodology (RSM) were used for this purpose. Quantitative changes were observed in the color parameters. Although the time variable strongly influenced them, the two sparkling wines were stable enough only at low temperatures after 12 months of ageing. During the wine ageing in bottle, an increase in the formation of polymeric red pigments can be suggested taking into account the losses observed in monomeric anthocyanins. The results obtained showed that the color of fully sparkling wines was more stable than that of lightly ones and, therefore, the shelf-life of the former ones could be longer.     

Pomegranate varietal wines: Phytochemical composition and quality parameters

Some well-known varieties of pomegranate, including Wonderful and Mollar de Elche, were used for the elaboration of varietal pomegranate wines as an interesting alternative to employ secondary quality and over-ripe fruit. The evolution of quality parameters with a technical relevance and the phytochemical composition of these fruit wines throughout the different winemaking stages were monitored. Noticeable changes occurred during wine elaboration, especially over the fermentation period. In addition, a significant role of the cultivar used in the phenolics profile was noted. Anthocyanins were the main bioactives conditioning both antioxidant capacity and colour parameters. Results pointed out that the elaboration of pomegranate wine from different varieties is a suitable means of industrialisation for underused fruits. Moreover, attending to the rich-in-phytochemicals composition of these novel quality drinks, pomegranate wine consumption could be suggested as a promising source of phenolic antioxidants with a plethora of health-promoting functions.     

Classification of South African red and white wines according to grape variety based on the non-coloured phenolic content

The phenolic content of South African wines was investigated for the purpose of their classification according to variety or cultivar. Twenty-two phenolic compounds were quantified by liquid chromatography in 55 red wines of five varieties and in 38 white wines of three varieties. Data were compared to literature values reported for wines from across the globe. ANOVA was used to determine significant concentration differences between the different varieties. Further grouping of the data was investigated by principal component analysis and cluster analysis. Finally, linear discriminant analysis was used to derive classification functions for the effective recognition of red and white wine varieties which allowed 100.0% and 97.4% correct recognition of red and white wines, respectively.     

Original article: Prediction of the colour and polyphenolic composition of the young red wines from the phenolic potential of the grapes

The phenolic potential of the grapes of Tannat, Cabernet Sauvignon and Merlot produced in the south region of Uruguay was analysed in four years. The grapes of Tannat had the highest total phenolic richness (A280 = 80.0), total anthocyanin potential (ApH1 = 2540 mg L^?1) and extractable anthocyanin potential (ApH3.2 = 1269 mg L^?1), although there were important differences between the years. Representative winemaking of each vineyard was carried out. The differences verified in the grapes phenolic indexes were related to the colour and polyphenolic composition of the wines. The correlations between the phenolic indexes of the grapes and the colour and polyphenolic composition of the wines were very high. The estimation of the polyphenolic richness and the extractability of the anthocyanins of the grapes allow to improve the management of the winemaking and the prediction of the chromatic characteristics and the global polyphenolic composition of the 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.     

Evaluation of the antiradical and reducing properties of selected Greek white wines: correlation with polyphenolic composition

The total hydroxycinnamate (THC) and total flavanol (TF) contents were determined in 26 selected Greek white wines of ‘Appellation of Origin of High Quality’ using well‐established spectrophotometric methodology. Furthermore, two parameters related to the antioxidant capacity of wines, the antiradical activity (A_AR) and the reducing power (P_R), were also determined using the stable DPPH· radical and a ferric reducing power assay respectively. THC content varied from 64.4 to 197.1 mg l^?1 chlorogenic acid equivalents (CGAE), whereas TF content exhibited larger variation, ranging from 3.3 to 205.3 mg l^?1 catechin equivalents (CTE). A_AR and P_R were found to range from 0.47 to 0.60 mM Trolox equivalents (TRE) and from 0.32 to 2.05 mM quercetin equivalents (QE) respectively. Regression analysis at 95% significance level indicated that reducing effects are likely to be exerted by the flavanol fraction (SF < 0.05), as opposed to antiradical efficiency which is primarily affected by the sum of THC and TF contents (SF < 0.05), suggesting that synergistic phenomena account for the overall antioxidant status of white wines. © 2002 Society of Chemical Industry     

Free radical scavenging and antibacterial activities of southern Serbian red wines

Free radical scavenging and antibacterial activities were determined for several red wines from different grape varieties from the southern Serbia wine region. The amount of polyphenols and anthocyanins in selected wines was investigated and the potential antibacterial activity of the wines against pathogenic strains of Staphylococcus aureus and Escherichia coli was also determined. The free radical scavenging and antibacterial activity of the wines was correlated with polyphenolic and anthocyanin content. The significant differences in the antioxidant and antibacterial activities between the wines from grape cultivars (Cabernet Sauvingon and Pinot Noir) and the indigenous varieties (Vranac and Prokupac) were not confirmed. The hypothesis of a protective effect of red wine is supported by our results that show that the red wines with higher amounts of polyphenols and anthocyanins had higher antioxidant and antibacterial properties.     

Anthocyanin,phenolic composition,colour measurement and sensory analysis of BC commercial red wines

This research established a database of analytical values associated with 173 commercial red wines from 7 vintages (1995–2001), 4 varieties (Pinot noir, Merlot, Cabernet Franc, Cabernet Sauvignon) and 13 vineyard locations within BC. Wines were analyzed for sulfur dioxide, pH, titratable acidity, phenolics, tartaric esters, flavonols, as well as copigmented, monomeric, polymeric, and total anthocyanins. Colour was evaluated using colour density, hue, and L, a¹, b¹ and chroma measurements. The sensory astringent qualities were characterized on a subset of 78 wines, using a panel of 12 judges. The panel evaluated the magnitude of the astringency, astringent aftertaste, oakiness and bitterness, as well as 3 astringent sub-qualities (surface roughness, drying, puckering). Data were analyzed by analysis of variance, principle component analyses, and canonical discriminant analyses to track the influence of variety, vintage and vineyard location. Trends were observable despite large variation in winemaking techniques. Red colour, colour density, copigmented, monomeric, polymeric and total anthocyanins were lowest in Pinot noir and highest in Cabernet Sauvignon wines. Younger wines had higher concentrations of copigmented, monomeric, and total anthocyanins than did older wines. Canonical discriminant analysis of the analytical and sensory determinations were successful in distinguishing the wines according to where the grapes were grown.     

Browning development in white wines: dependence on compositional parameters and impact on antioxidant characteristics

Browning is a serious problem in relation to white wine quality and mostly affects the sensory attributes, whereas its impact on the dietary value of wines has never been investigated. Browning, however, 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, 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 consequences of browning on the reducing power and antiradical activity were assessed. It was shown that none of the parameters examined (titratable acidity, pH, total SO₂, total polyphenols and total flavanols) play an important role in browning onset, but SO₂ appeared to exert a statistically significant influence (r²=0.6394, P<0.05) on the percentage change in the antiradical activity. Evidence also suggested that browning development might be prominently associated with decreases in both antiradical activity (r²=0.7891, P<0.01) and reducing power (r²=0.6925, P<0.05).     

Chemometric and phenolic attributes of blended wines assessed by multivariate techniques

The aim of the study was to investigate the quality of blended wines produced from Vitis vinifera L. Cabernet Sauvignon, Merlot and Sauvignon blanc grapes. Wines were processed according to accepted conventional methods for white and red wines. Blended wines were produced with different ranges (25, 50, 75 and 100%) of Cabernet Sauvignon, Merlot and Sauvignon blanc wines. Produced wines were evaluated for total phenols (mg/L), total tartaric esters (mg/L caffeic acid), total flavonols (mg/L quercetin), chemometric parameters such as D280%, D420%, D520%, D620%, dA%, CD%, T, CI%, R%, Y% and B%, CIELAB parameters, protein, total and volatile acidity. Analyses on an n‐dimensional scale demonstrated the relationships among the wines of different grape origins and different blending ratios. On the basis of these differences, two main groups were plotted using principal component analysis and cluster analysis. The results demonstrate the possibilities of optimizing wines on the basis of defined parameters. Copyright © 2015 The Institute of Brewing & Distilling     

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.     

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.     

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.     

Varietal differentiation of Tannat,Cabernet-Sauvignon and Merlot grapes and wines according to their anthocyanic composition

The aim of this paper was to establish the correspondence between the anthocyanic profiles of grapes and wines produced in Uruguay. For this purpose, Tannat, Cabernet-Sauvignon and Merlot vineyards in 2002 and 2003 were considered. Grapes samples were taken in the harvest and were peeled, and the skins were stored at −20 °C until analysis. After that, skins were macerated in a 12% ethanol and pH 3,2 solution for 24 hours. Vinifications were carried out with 50 kg of grapes and two replications per vineyard. The anthocyanic composition of the skins extracts and the wines were analysed by H.P.L.C. Delphinidin, petunidin and non-acylated glucosides proportions were significantly higher in Tannat skins and wines. Malvidin and acetates proportions were significantly higher in Cabernet-Sauvignon grapes and wines. Peonidin and coumarates proportions were higher in Merlot skins and wines. The relation between the acetyl and coumarylic forms allowed the differentiation of Cabernet-Sauvignon grapes and wines from Merlot and Tannat, but not these among themselves. The combined consideration of the anthocyanic forms proportions allowed the discrimination of the totality of the grapes and wines samples of each variety.