Influence of chips,lees and micro-oxygenation during aging on the phenolic composition of a red Sangiovese wine

A red Sangiovese wine was aged using separate or combined different technological treatments and techniques (chips, chips and micro-oxygenation, chips and lees and micro-oxygenation), to evaluate their influence on phenolic compounds.     

Micro-oxygenation and oak chip treatments of red wines: Effects on colour-related phenolics,volatile composition and sensory characteristics. Part II: Merlot wines

The character of Merlot wines after the treatments of micro-oxygenation and subsequent chips addition, as regards the colour-related phenolics, volatile composition and sensory characteristics, was studied. An increase in the degree of polymerisation of red pigments and a decrease in the value of the red component of the colour (a^*) and the degree of co-pigmentation were observed. The concentrations of monomeric anthocyanins and anthocyanin-derived pigments, such as hydroxyphenyl-pyranoanthocyanins and anthocyanin-ethyl-flavan-3-ol adducts, significantly decreased. With regard to the wine aroma, the micro-oxygenation produced a decrease of some esters, alcohols and benzenic compounds and increased some terpenes and C₁₃-norisoprenoids. With regard to sensorial analysis, micro-oxygenation treatment resulted in higher scores for the red fruit and spicy attributes and caused the presence of new attributes (nutty and sweet fruit). This technique produces a lower level of the typical oak chip aromas (vanilla and woody) in Merlot wines.     

Micro-oxygenation and oak chip treatments of red wines: Effects on colour-related phenolics,volatile composition and sensory characteristics. Part I: Petit Verdot wines

In this paper, the effects of micro-oxygenation before malolactic fermentation and oak chip treatments on Petit Verdot red wines have been evaluated. Our attention was focused on the colour characteristics, the phenolic compounds related to the colour of red wine, the volatile compounds, and the sensory characteristics of the wines. The micro-oxygenation treatment promoted the stabilisation of red wine colour by increasing the formation of colour-related phenolic compounds (higher concentrations of pyranoanthocyanins and anthocyanin-ethyl-flavan-3-ol adducts). Red wine aroma quality was improved with the addition of oak chips (eugenol and 4-vinyl-guaiacol concentration increased). Micro-oxygenation treatment resulted in higher scores for the plum/currant and spicy attributes, as well as the appearance of tobacco and nutty notes which were absent in the non-treated wines. Nevertheless, the typical oak chip aromas (vanilla and woody) were observed to a lesser extent in wines obtained by micro-oxygenation.     

Influence of different aging systems and oak woods on aged wine color and anthocyanin composition

The evolution of a red wine, Cigales appellation in origin, was studied during its storage in three different aging systems (barrels, chips, and staves) made of different kinds of oak wood (American, French, and Hungarian). The results obtained were analyzed in order to determine the content of anthocyanins in wine according to the aging system used. The studied variables were monoglucosides of delphidin, cyanindin, peonidin, petunidin and malvidin (as acetic and p-coumaric esters), as well as vitisin A, malvidin-3-O-caffeylglucoside, and color variables. The relationship between the anthocyanins and color variables stressed the importance of these compounds during the formation of pigments characteristic of aged wine, and highlighted how they are affected by the aging system chosen.Analysis of the results allowed us to define the evolution of the wine accordingly to the aging system and the botanical species of wood used. Wine treated with chips evolved more quickly than wines treated with the other two systems, because there was a higher loss of anthocyanins and an increase in brownish tonalities. On the other hand, wine treated with Hungarian oak wood suffered a slightly higher loss of anthocyanins than those aged with French and American oak wood.     

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).     

Nitrogen compounds and polysaccharides changes during the biological ageing of sherry wines

Biologically aged sherry wines are elaborated by the so called “criadera” and “solera” system, which essentially involves development of the yeast on the wine surface forming a film velum for several years. In this work, a study on the changes that take place in polysaccharide and nitrogen compounds during the elaboration of sherry wines has been undertaken. The evolution of monosaccharides derived from polysaccharides as well as of amino acids and polypeptides have been investigated in wine samples at different stages of the elaboration process (young wines, “sobretablas”, “criaderas” and “solera”). Mannose, galactose, glucose and arabinose were detected in all analyzed wines; mannose being the most abundant carbohydrate, particularly in wines that aged longer. Glucose and galactose content also increased during the biological ageing of these wines, whereas arabinose concentration lowered during all period. Nitrogen compounds experimented a decrease and even some amino acids were not detected at the end of the ageing. Considering the increase in mannose and the decrease in amino acid levels, it is presumable that autolysis and growth of yeast occur at the same time during the elaboration of the sherry wines.     

Partial characterization of peptides from red wines. Changes during malolactic fermentation and ageing with lees

The peptide fraction of an industrially manufactured red wine has been studied during malolactic fermentation, carried out in stainless-steel tanks or in the barrel and ageing in the barrel, with or without lees, for 12 months. Peptides were fractionated using Sephadex LH-20 and Cosmosil 140 C₁₈-OPN columns, giving two fractions in relation to peptide polarity. The most important changes were detected during malolactic fermentation and during the ageing in barrel with lees. The peptides present in the wine could be glycopeptides from grape or yeast. Most amino acids in the most polar peptides were aspartic acid and/or asparagine, glutamic acid and/or glutamine, serine, glycine, α-alanine and tyrosine and, in the less polar fraction, were glycine, α-alanine and leucine. The amino acid distribution is most different in the most polar fraction, among the studied wines, owing to autolysis and hydrolysis of the polypeptides and proteins.     

Conventional and enzyme-assisted autolysis during ageing over lees in red wines: Influence on the release of polysaccharides from yeast cell walls and on wine monomeric anthocyanin content

HPLC with refractive index detection (HPLC/RI) was used to study the autolytic release of polysaccharides from the cell walls of six strains of Saccharomyces cerevisiae and the commercial yeast species Sacch. uvarum in a model medium over a nine month period of ageing over lees. The effect of adding β-glucanase was also studied. In the presence of this enzyme autolysis was complete within 2–3 weeks; conventional autolysis needed to proceed for at least five months before large quantities of released polysaccharides could be detected. The final polysaccharide profile of the model medium obtained by enzyme-assisted autolysis was, however, different to that obtained by conventional autolysis, with more fragments of smaller molecular weight and a greater grouping of molecular sizes in the HPLC/RI peaks. The influence on the monomeric anthocyanin content of commercial red wines was examined by HPLC with photodiode array detection (HPLC/PDAD). Ageing over lees without enzymes appeared to have a protective effect on the total monomeric anthocyanin content, while the use of β-glucanase led to a large reduction in their concentration, probably via the undesirable activity of β-glucosidase impurities.     

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.     

The magnitude of copigmentation in the colour of aged red wines made in the Canary Islands

In order to study the magnitude of the copigmentation phenomenon in aged red wines, 84 samples of Listán negro wines were collected from several wineries in the Canary Islands. They were analysed at 1 and 2 years of age. The contribution of free anthocyanins, copigmented anthocyanins and polymeric pigments to the colour of wine, and the total phenols were determined. Moreover, coloured anthocyanins, total anthocyanins, percentage of total anthocyanins in coloured form and chemical age factor, and the chromatic characteristics of the wines were determined. The contribution to colour due to copigmented anthocyanins in these aged red wines remained at 22.3 and 18.5% (mean values) after 1 and 2 years of age, respectively, and the free anthocyanins at 37.0 and 32.5%. A comparison between the results obtained by Somers and Boulton methods has been established.     

Changes in the volatile composition of red wines during aging in oak barrels due to microoxygenation treatment applied before malolactic fermentation

Microoxygenation is a wine-making technique consisting in the addition of small and controlled amounts of oxygen. This study has examined the effect of this technique on the volatile composition of two red single variety wines during two successive vintages. The microoxygenation treatment was applied at the end of alcoholic fermentation and before beginning malolactic fermentation. Once the microoxygenation treatment had finished, wines were aged in new American oak barrels for 12 months. The results obtained showed that the microoxygenation treatment did not cause significant changes in the varietal and fermentation volatile compounds, however microoxygenation slowed down the extraction of some of the volatile compounds extracted from wood. A varietal and vintage effect was also observed for some of the compounds studied.     

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.     

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.     

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.     

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.     

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.     

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.     

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.