Differences in the phenolic composition and sensory profile between red wines aged in oak barrels and wines aged with oak chips

The aim of this study was to evaluate the similarities or differences in the phenolic composition and the sensory characteristics between wines traditionally aged in new French and American barrels for different periods of time, and wines aged for 30 days with different kinds (different geographical origin al toasting degree) of oak chips. This study was carried out with two grape varieties, Mencía and Tinta del País, and in two consecutive vintages. The results obtained indicated that it was not possible to obtain wines aged with chips with sensory characteristics similar to those aged for a long time in new barrels, independently. However, the results showed that the use of oak chips could be a good alternative for elaborating young wines with slight olfactory and gustative wood notes quite similar to wines aged in new barrels for short periods of time (about three months).     

Chemical and sensory changes in white wines fermented in the presence of oak chips

Summary Three samples of French oak and one sample of American oak were analyzed by different gas chromatographic-mass spectrometric (GC/MS) methods. Two methods of quantifying the main volatile compounds in oak wood were compared, namely, Direct Thermal Desorption coupled with GC/MS and analysis of mixtures of water-ethanol and wines that had been in contact with oak chips by extraction using an organic solvent followed by GC/MS analysis of the extract. The ratio of the two oak lactones released into the wine by the oak chips was the same as the ratio observed in original, untreated wood. These substances are of particular sensory importance in wines aged in oak wood barrels. Thus, the use of oak chips in white wines may be advantageous. The wines steeped with the oak chips improved their acceptability rating 2 points on a scale of 9.     

Anthocyanin pattern of Tempranillo wines during ageing in oak barrels and storage in stainless-steel tanks

The anthocyanin fingerprint of Tempranillo wines made with grapes from two different vineyards of Rioja Alta has been studied by high-performance liquid chroatography during their ageing in oak barrels and their storage in stainless-steel tanks. The data were submitted to multifactorial analysis of variance, taking into account several factors: vineyard, age of wines, type of wine (free run wine and a coupage of free run wine and press wine), and type of container (oak barrels or stainless-steel tanks). The results indicate that both the length of ageing or storage and the vineyard where the grapes were grown affect the anthocyanin fingerprint of wines. The effect of the other two factors (type of wine and type of container) on the anthocyanin fingerprint of wines was quite low, despite the differences observed in several spectrophotometric parameters related to colour and phenolics.     

Volatile composition and sensory characteristics of Chardonnay wines treated with American and Hungarian oak chips

Toasted or non-toasted chips of oak woods of different geographical provenances were macerated in Chardonnay wines (4 g/l) during a period of 25 days. Oak lactones were detected in significant quantities in wines treated with American oak. Only trace amounts of oak lactones were detected in the wines treated with Hungarian oak. Toasting of the oaks increased the quantities of the compounds derived from the thermal degradation of lignin: vanillin, eugenol, guaiacol and its derivatives and the pyrolysis of cellulose and hemicellulose: furfural and 5-methyl furfural, and decreased the concentrations of the two isomers of oak lactones. The concentrations of the majority of the volatile compounds did not present statistically significant differences between 15 and 25 days. However, the wines preferred by the tasters and with maximum intensity of the sensory attributes acquired were those treated with oak chips for 25 days. Chemical and sensorial analyses of wines revealed that the effect of the toasting of oak chips on wine characteristics was greater than the type of oak used. All wines studied were positively evaluated by the panellists.     

Immobilized yeasts in κ-carragenate to prevent browning in white wines

Yeasts immobilized in κ-carragenate gel beads of variable size were used to delay accelerated browning of sherry pale white wines at 35°C. Based on the results, the wines maintained into contact with no gel took 27 days to reach the browning limit level for commercial wines of this type (A420 value of 0.180 au). However, the wines containing gel beads 1, 2 or 3 mm thick reached such a level 24, 30 and 33 days later, respectively, than the previous ones. After 27 days of contact with gel beads, the wines exhibited decreased contents in phenolic acids, hydroxycinnamic esters and flavan-3-ol monomers and dimers. On the other hand, the yeast gels substantially delayed browning of wines stored at 19°C in bottles for 1 year. Thus, while the wine stored without gels reached the commercial rejection limit for A420, those stored in contact with gel beads exhibited virtually no browning and only slight changes in their sensory properties, although they were still acceptable for consumption.     

Concentration of volatile compounds in Chardonnay wine fermented in stainless steel tanks and oak barrels

The influence of the type of container used in alcoholic fermentation on the formation of volatile compounds in wine from Chardonnay variety was studied. To do so, must from Chardonnay variety was fermented in both stainless steel tanks and in new Nevers oak barrels. The results obtained showed that wine fermented in barrels had a greater concentration of higher alcohols and esters than wine fermented in tanks. Concentration of isoamyl acetate, ethyl hexanoate, ethyl octanoate and ethyl decanoate was four times higher in wine fermented in oak barrels than in wine fermented in stainless steel tanks. With regard to the concentration of acids, a greater concentration of medium-chain fatty acids (C6:0–C10:0) was noticeable in wine fermented in oak barrels. Given that these acids are toxic for the yeasts, they may be responsible for the slower fermentation rate of wine fermented in oak barrels.     

Colour correction in white wines by use of immobilized yeasts on κ-carragenate and alginate gels

Pale white wines of the sherry type were subjected to different colour correction treatments based on the use of gel beads consisting of variable proportions of yeasts immobilized on two different polysaccharides (κ-carragenate and alginate). All treatments were found to reduce colour in the control wine, the reduction increasing in a non-proportional way with the increase in yeasts concentration and the decrease in polysaccharide/yeasts ratio. On the same polysaccharide/yeast ratios, κ-carragenate gels proved more efficient than alginate gels. Except for some acids, the concentrations of phenolic compounds were reduced by all treatments (especially those involving κ-carragenate). Based on their colour-correcting ability, moderate retention of human healthy phenolic compounds and similarity to activated carbon in sensory terms, κ-carragenate gels containing a 2 g/L concentration of yeasts in a 2:2 polysaccharide/yeasts ratio represent an effective alternative to fining agents traditionally used in the production of white wines.     

Employment of near infrared spectroscopy to determine oak volatile compounds and ethylphenols in aged red wines

The aim of this work was to study the ability of NIR spectroscopy to determine oak volatile compounds and ethylphenols levels in aged red wines. For this purpose 510 wines aged with different storage time and in different oak barrel types were analyzed. Calibration models were developed from SBSE-GC–MS and NIR data using partial least squares (PLS) regression. In order to validate the calibration, full cross validation was employed. Results showed that the calibration statistics were very good (R² > 0.86) for all the compounds studied. In wines aged in French and in American and French oak barrels, and in “reserva” and “gran reserva” wines, the residual predictive deviation (RPD) obtained was higher than 1.5 in all the compounds and it was higher than 2 in some of the cases. In conclusion, near infrared spectroscopy can be used as a rapid tool to determine oak volatile compounds and ethylphenols in aged red wines.     

Phenolic profile in varietal white wines made in the Canary Islands

In the Canary Islands there are some lesser-known varieties of white grapes. The aim of this study is to examine the differences in phenolic compounds and colour coordinates between three varietal white wines, Listán blanco, Verdello and Gual, cultivated in a very special region due to its location and its low irrigation. Using a HPLC method, we have measured 19 compounds of different phenolic groups. The wines of this study presented high values of these compounds. The Gual variety had the highest significant values of the cis and trans-resveratrol, trans-piceid and total resveratrol content with an average of 3.94 mg/L. The ratio of trans-coutaric acid/trans-caftaric acid concentration allowed the differentiation also of Gual variety. Furthermore, caftaric acid has been shown to be a chemotaxonomic parameter for white wines.     

Influence of oak woods of different geographical origins on quality of wines aged in barriques and using oak chips

Wine ageing in wood barrels is a traditional practice in quality wine-making areas. It is generally believed that the organoleptic characteristics of wines aged in barrels are deeply influenced by wood geographical origin, as well as by age of barrels (new or used).     

Polyphenolic composition of Croatian wines with different geographical origins

Twelve samples of commercially available wines produced in three different wine-growing sub-regions of Croatia were analysed, to determine their polyphenolic content and associate the concentration levels of these compounds with the geographical origin of wine. Total phenols were analysed according to the Folin–Ciocalteu method. Fifteen individual polyphenols were analysed by a reverse-phase HPLC method that used gradient elution and diode array detection. Wines made in Central and Southern Dalmatia were richest in total phenols and individual polyphenols. Flavonols and trans-resveratrol pattern were the basis for the classification of samples according to their geographical origin and type of wine.     

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).     

Changes in contents of phenolic compounds during maturing of barrique red wines

Concentrations of derivatives of benzoic and cinnamic acids and furaldehyde were studied during maturing of a red wine (a mixture of Cabernet Sauvignon and Merlot) in barrique barrels (Quercus robur). Samples were taken at three-week intervals over 6 months. The influence of degree of toasting of the wood on the amount of phenolic compounds in barrique wine was also investigated. The samples were pre-separated using a solid-phase extraction on an RP 105 polymeric sorbent and analysed by high-performance liquid chromatography with UV-DAD detection. Gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, benzoic and ellagic acids and p-hydroxybenzaldehyde, vanillin, 2-furaldehyde, 5-methoxy-2-furaldehyde and 5-methyl-2-furaldehyde were identified in the extracts of natural and toasted wood chips and in the extracts of the wine. Syringaldehyde was identified only in the extracts of the toasted wood chips. Ellagic acid can be regarded as a characteristic compound of barrique wine ageing and its constant level during some periods could become a marker of maturity of barrique wines. Due to the absence of furaldehydes in natural wines, these compounds can be considered as typical components of barrique wines and so they can serve as a marker of authenticity of barrique wines.     

Wine consumption habits and consumer preferences between wines aged in barrels or with chips

BACKGROUND: The use of oak wood pieces in winemaking is increasing, but the acceptance of this technique by consumers is unknown. For that reason, the main aim of this study was to measure consumers' opinion of red wines made with this new technique, their acceptance of them and their intention to purchase these wines. A preference ranking test was also carried out. RESULTS: A specific questionnaire was drawn up for this study and 65 frequent red wine consumers tasted four wines, two aged traditionally in barrels and two macerated with chips, and a forced choice preference test was carried out. Fifty‐five per cent of respondents said that they would not buy wines made using oak chips, although most respondents would buy these wines if, after tasting them, they were as pleasant and had the same quality as the wines aged traditionally in barrels. CONCLUSION: Wines obtained with oak wood fragments were not significantly rejected either by consumers who answered the questionnaire or by consumer tasters, which could be due to the large disparity of preferences found among tasters. The results clearly indicate that producers should develop each wine taking into account the specific preferences of each consumer group. Copyright © 2011 Society of Chemical Industry     

Colour of Amontillado wines aged in two oak barrel types

The colour of 123 Amontillado wines from “Condado de Huelva” Designation of Origin, made from white grapes of the Zalema variety and slowly aged in different types of wood casks, has been studied. Colour differences due to different materials from which the casks were manufactured (Spanish and American oak wood) have been appreciated. Tristimulus methods have been applied following the recommendations of the International Commission on Illumination (CIE). Colour parameters (, , , , h _ab10) from CIELAB space and saturation () from CIELUV space have been used for calculus. The results indicated differences for lightness and saturation, which allows one to establish the areas of predominant colour for the characterisation of the colour of this type of wines. Multivariate statistical analysis demonstrated that different groups of selected variables give similar results, meaning that the wines aged in American oak barrels and Spanish oak barrels show significant (p<0.05) differences in colour variables. Three supervised learning methods, classification tree, linear discriminant analysis and back-propagation artificial neural network, have been applied for distinguishing between classes.     

Chemical and chromatic characteristics of Tempranillo,Cabernet Sauvignon and Merlot wines from DO Navarra aged in Spanish and French oak barrels

The oenological quality of Spanish oak wood from Navarra (Quercus petraea Liebl.) in relation to French wood of recognised quality in cooperage has been evaluated. We have studied the effects of the Spanish wood on wine evolution during ageing, in regards to chromatic characteristics, polyphenols, and volatile compounds related to oak wood, in three different mono-varietal wines (cv. Tempranillo, cv. Cabernet Sauvignon and cv. Merlot) from the Origin Denomination Navarra. The results were compared with those obtained for the same wines aged in French oak barrels from central regions of France, obtained from five different French and Spanish cooperages.     

Changes in the concentration of volatile oak compounds and esters in red wine stored for 18 months in re-used French oak barrels

Studies were made of changes in concentration of oak-wood-derived volatiles and the evolution of esters in red wine during storage in twice-used French oak barrels. Wine samples were taken after 8, 10, 12, 15, and 18 months maturation in the barrels. Results showed that most of the volatile compounds extracted from the wood (furanic compounds, volatile phenols, lactones) reached maximum concentration between 10 and 12 months of barrel storage. After 18 months of maturation many of the compounds showed concentrations similar to those found after 10 to 12 months. However, the concentrations of furfural, 5-methyl furfural, furfuryl alcohol, coniferaldehyde, acetovanillone and phenol in wines aged for 18 months were lower than those reached after 10 to 12 months. The concentration of the ethylphenols increased right up to 18 months of ageing, which can only have a negative impact on the quality of the wine. There were few modifications in the concentration of esters, except for ethyl lactate which reached peak concentration after 12 months maturation and decreased thereafter.     

Influence of some prefermentative treatments on aroma composition and sensory evaluation of white Godello wines

The influence of the static settling time and the addition of ammonium salts on basic parameters, aroma composition and tasting of white Godello wines have been studied. The statistical analysis showed a significant influence of those treatments on several analytical parameters. The static settling time proved to be very influential on total acidity, free sulphur dioxide, esters, terpenols and fatty acids, while the addition of ammonium salts showed a significant effect on higher alcohols and ethyl lactate. According to the odour active value (OAV), 14 out of 47 studied volatile components had OAV >1 in all the analysed wines, while six volatile components showed OAV >1 only for some of them. Ethyl octanoate, isoamyl acetate and ethyl hexanoate showed the highest OAV values. During the tasting session, the two studied factors became relevant, being better valued the wine made with must containing higher limpidity and with the addition of diammonium hydrogen phosphate.     

The development of esters in filtered and unfiltered wines that have been aged in oak barrels

Esters are quite important for the aroma of aged red wine as they contribute to the fruity complex nature of this wine. This research paper measured the development of esters during maturation of Merlot red wines. These wines had different amounts of turbidity. The wine was aged for 18 months either after filtration with diatomaceous earth or without filtration. Both American and French oak barrel were used for storage. The results obtained showed that the unfiltered wine had a greater concentration of esters at the end of the storage period than the filtered wine. Fatty acid and ethanol esters decreased more than isoamyl acetate, independently of filtration. Ethyl octanoate and ethyl decanoate decreased both in filtered and unfiltered wine. Isoamyl acetate was formed in unfiltered wine and ethyl butyrate and ethyl hexanoate decreased in filtered wine while they remained constant in unfiltered wine.     

Consideration of the influence of aging process,type of wine and oenological classic parameters on the levels of wood volatile compounds present in red wines

The contents of the volatile compounds extracted from wood: cis- and trans-whiskylactones, vanillin, syringaldehyde, furfural, 5-methylfurfural, eugenol, guaiacol, p-ethyl-phenol and p-ethylguaicol have been studied in 12 single-variety wines aged in new American oak barrels. The concentration of these compounds were determined after the following combinations of time in wood and time in bottle: 0 months in wood plus 18 months in bottle, 4 months in wood  + 14 months in bottle, 9 months in wood + 9 moths in bottle and 12 months in wood + 6 months in bottle. According to the composition of the wines, it is possible to conclude in general, that, the extraction of these compounds was faster during the first four or 9 months of aging in wood, depending on the wines. After 12 months of oak maturation, the extraction of these compounds slowed down. Furthermore, the final concentrations of these volatile compounds were different among studied wines. These differences could be related to some of the values of some of their oenological parameters, such as the contents of tartaric acid and sulphur dioxide of each wine.