RESUMEN

The primary cause of bottled wine sediment is tartrate crystal precipitation. To prevent this, wines undergo a stabilization process before bottling. The most commonly used method is cold stabilization, which induces the precipitation of tartrate crystals that are then removed, thereby eliminating the excess ions that cause instability in wine. Another approach to tartaric stabilization is using enological stabilizers with a colloid protective effect, which prevents the formation of tartrate crystals. The most commonly used tartaric stabilizers are sodium carboxymethylcellulose (CMC) and metatartaric acid. However, both have drawbacks: they are semi-synthetic products, and metatartaric acid degrades over time, losing its stabilizing effect. This study aims to compare the effects of cold stabilization, stabilization with CMC, and metatartaric acid on the chemical composition, particularly the volatilome, of white, rosé, and red wines. Cold stabilization significantly impacted the wine volatilome, especially in white and rosé wines, by decreasing total alcohols and increasing total esters. It also reduced the color intensity of rosé and red wines by lowering monomeric anthocyanins. In contrast, enological stabilizers had minimal impact on the wines' phenolic composition, chromatic characteristics, and volatilome. The sensory impact of cold stabilization is complex; it can potentially enhance the aroma of white and rosé wines by increasing ester VOCs and decreasing higher alcohols, but it negatively affects the color of rosé and red wines.

RESUMEN

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability.

Asunto(s)

RESUMEN

The colour of the different Port wine styles and indication of age (IOA) categories is a distinctive quality parameter influenced by the grapes and ageing process. The impact of Port wine styles and IOA on phenolic composition is mostly unknown. This work aims to study the chromatic characteristics (CIELab) and their relation with the phenolic composition of White, Tawny, and Ruby Port wines and evaluate the feasibility of its utilisation for their discrimination. Port wine styles and IOA categories can be discriminated by their chromatic characteristics, using different data analysis models. The higher b* values, corresponding to the brownish/yellowish colour of Tawny and White Ports belonging to higher IOA categories, seem more related to the sugar browning than the oxidative change in phenolic compounds. However, this last process is essential for the red colour (a*) decrease of Tawny Port wines with higher IOA.

Asunto(s)

RESUMEN

Trichloroanisole (TCA) in wine results in a sensory defect called "cork taint", a significant problem for the wine industry. Wines can become contaminated by TCA absorption from the atmosphere through contaminated wood barrels, cork stoppers, and wood pallets. Air-depleted solvent-impregnated (ADSI) cork powder (CP) was used to mitigate TCA in wines. The ADSI CP (0.25 g/L) removed 91% of TCA (6 ng/L levels), resulting in an olfactory activity value of 0.14. A Freundlich isotherm described ADSI CP TCA adsorption with irreversible adsorption and a KF = 33.37. ADSI CP application had no significant impact on the phenolic profile and chromatic characteristics of red wine. Using headspace sampling with re-equilibration, an average reduction in the volatile abundance of 29 ± 15%, 31 ± 19%, and 37 ± 24% was observed for the 0.10, 0.25, and 0.50 g/L ADSI CP, respectively. The alkyl esters and acids were the most affected. The impact observed was much lower when using headspace sampling without re-equilibration. Isoamyl acetate, ethyl hexanoate, ethyl hexanoate, and ethyl decanoate abundances were not significantly different from the control wine and 0.25 g/L ADSI CP application. Thus, ADSI CP can be a new sustainable fining agent to remove this "off-flavor" from wine, with a reduced impact on the wine characteristics.

Asunto(s)

RESUMEN

In white wine production, a great effort is made to avoid extensive contact with oxygen, which might adversely affect color and aroma. In this work, the impact of bulk transportation on white wine oxygen uptake and the effect of deoxygenation on white wine dissolved oxygen levels, as well on the phenolic composition and chromatic characteristics of white wines stored for nine months, were studied. Transportation increased the white wine dissolved oxygen content (117 and 181% in the wines studied) that increased the free sulfur dioxide loss during storage. Moreover, deoxygenation of white wines reduced the increase in the yellow color of white wines during storage, probably related to the higher levels of free sulfur dioxide that remain in these wines during storage. Furthermore, the amount of wine phenolics also have a decisive influence on wine color characteristics evolution, with increased levels of total phenolic compounds increasing the variation in the b *(measure of yellowness) values of the wines after nine months of storage. Results show the negative impact of bulk transportation on white wine color characteristics; however, wine deoxygenation is a good practice to minimize those aspects, preserving color characteristics.

RESUMEN

BACKGROUND: The use of holm oak (Quercus ilex) chips as a potential alternative wood and the application of hydrostatic high pressure (HHP) as an alternative technique to accelerate the release to the wine of wood-related compounds within a short processing time were evaluated. METHODS: Five treatments were investigated: (i) bottling without any treatment (B); (ii) and (iii) bottling after maceration (5 g/L) of holm oak chips with HHP treatments (400 MPa, 5 and 30 min) (HHP5, HHP30); (iv) bottling after maceration during 45 days with chips (M), and; (v) maceration in tanks without chips (T). The effects of treatments on general parameters, polyphenols, color, and sensorial characteristics of red and white wines were investigated over 180 days. RESULTS: HHP5, HHP30, and M increased the polyphenols content, thus modified the chromatic characteristics regarding B and M treatments of white wines, also the tasters differentiated HHP5, HHP30, and M from B and T. However, these effects were not observed in red wines. Thus, the effect of the wood depends on the type of wine in which it is used. CONCLUSIONS: This research contributes to better knowledge about these chips as a new alternative wood species and the use of HHP as a useful technology to accelerate the aging of wines.

RESUMEN

In this work, the effect of pre-fermentative skin maceration (PFSM) on the chemical composition of the macromolecular fraction, polysaccharides and proteins, phenolic compounds, chromatic characteristics, and protein stability of Albariño monovarietal white wines was studied. PFSM increased the extraction of phenolic compounds and polysaccharides and reduced the extraction of pathogenesis-related proteins (PRPs). PFSM wine showed significantly higher protein instability. Sodium and calcium bentonites were used for protein stabilisation of wines obtained with PFSM (+PFSM) and without PFSM (-PFSM), and their efficiencies compared to fungal chitosan (FCH) and k-carrageenan. k-Carrageenan reduced the content of PRPs and the protein instability in both wines, and it was more efficient than sodium and calcium bentonites. FCH was unable to heat stabilise both wines, and PRPs levels remained unaltered. On the other hand, FCH decreased the levels of wine polysaccharides by 60%. Sodium and calcium bentonite also decreased the levels of wine polysaccharides although to a lower extent (16% to 59%). k-Carrageenan did not affect the wine polysaccharide levels. Overall, k-carrageenan is suitable for white wine protein stabilisation, having a more desirable impact on the wine macromolecular fraction than the other fining agents, reducing the levels of the wine PRPs without impacting polysaccharide composition.

RESUMEN

Aflatoxins B1 and B2 are two highly toxic mycotoxins that have been sometimes found in wines. Currently, no technological solution is available to reduce or eliminate aflatoxins from wines when they are present. Therefore, this work aims to study the efficiency of already approved wine fining agents like activated carbon, potassium caseinate, chitosan, and bentonite for aflatoxins B1 and B2 removal from white and red wines. It was observed that the fining agents' efficiency in removing aflatoxins was dependent on the wine matrix, being higher in white than in red wine. Bentonite was the most efficient fining agent, removing both aflatoxins (10 µg/L total) from the white wine and 100% of aflatoxin B1 and 82% of aflatoxin B2 from red wine. The impact of bentonite on white wine chromatic characteristics was low (color difference, ΔE* = 1.35). For red wine, bentonite addition caused a higher impact on wine' chromatic characteristics (ΔE* = 4.80) due to the decrease in total anthocyanins, although this decrease was only 1.5 points of color intensity. Considering the high efficiency of bentonite in aflatoxins B1 and B2 removal and despite the impact on red wine color, bentonite is a very good technological solution for aflatoxin removal in white and red wines.

RESUMEN

BACKGROUND: Due to the current dominance of a few grape varieties in the wine market, the aim of this work was to study the detailed phenolic and volatile composition, chromatic characteristics, and sensorial properties of red wines elaborated with new Vitis vinifera grapes (Moribel and Tinto Fragoso) identified using the High Perfomance Liquid Chromatography-Diode Array Detector-Electrospray Ionization-Tandem Mass Spectrometry (HPLC-DAD-ESI-MS/MS), Gas Chromatography- Mass Spectrometry (GC-MS), CIELab color space, and Napping ® techniques. RESULTS: Tinto Fragoso wine showed higher phenolic content than Moribel, with more anthocyanins, flavonols, and stilbenes. These wines also contained anthocyanin diglucosides not reported for Vitis vinifera wines. The odor activity values of free volatile compounds were calculated to indicate their influence on wine aroma, the fruity aromas of Moribel standing out particularly. The wines studied were positively evaluated by the tasters. Moribel's sensory profile was characterized by red fruit aromas and Tinto Fragoso showed more aromatic intensity and persistence in the mouth. CONCLUSION: The results obtained from the first characterization of red wines made from novel Vitis vinifera grapes suggest that Moribel and Tinto Fragoso could be appropriate raw materials for the elaboration of quality young red wines. Tinto Fragoso provided wines with sensorial properties different from those of Tempranillo, and could be an alternative to the well known red wines on the market. © 2018 Society of Chemical Industry.

Asunto(s)

RESUMEN

Data in this article presents the changes on phenolic compounds and headspace aroma abundance of a red wine spiked with 4-ethylphenol and 4-ethylguaiacol and treated with a commercial crustacean chitin (CHTN), two commercial crustacean chitosans (CHTB, CHTD), one fungal chitosan (CHTF), one additional chitin (CHTNA) and one additional chitosan (CHTC) produced by alkaline deacetylation of CHTN and CHTB, respectively. Chitin and chitosans presented different structural features, namely deacetylation degree (DD), average molecular weight (MW), sugar and mineral composition ("Reducing the negative sensory impact of volatile phenols in red wine with different chitosan: effect of structure on efficiency" (Filipe-Ribeiro et al., 2018) [1]. Statistical data is also shown, which correlates the changes in headspace aroma abundance of red wines with the chitosans structural features at 10 g/h L application dose.

RESUMEN

"Brett character" is a negative sensory attribute acquired by red wines when contaminating Dekkera/Brettanomyces yeasts produce 4-ethylphenol and 4-ethylguaiacol, known as volatile phenols (VPs), from cinnamic acid precursors. In this study, chitins and chitosans with different structural features, namely deacetylation degree (5-91%) and molecular weight (24-466kDa) were used for the reduction of this sensory defect. Chitins and chitosans decreased 7-26% of the headspace abundance of VPs without changing their amounts in wines. The efficiency of reduction increased with the deacetylation degree and applied dose. Reduction of headspace abundance of VPs by chitosans enabled significant decreases in the negative phenolic and bitterness attributes and increased positive fruity and floral attributes. Results show that chitosan with high deacetylation degrees, including fungal chitosan, which is already approved for use in wines, is an efficient approach for reducing the negative sensory impact of VPs in red wines.

Asunto(s)

RESUMEN

In the recent research, the copigmentations of malvidin-3-O-glucoside with eight types of phenolic copigments have been investigated. The influence of the pigment/copigment molar ratio, the reaction temperature, the pH and the ethanol content of solutions has been examined. The results showed that the copigmentation effect was dependent on not only the particular structures of the phenolic compounds but also the factors of the reaction systems. The increase of the copigment concentration can strengthen the copigmentation effect, improve the solution color, and enhance the red-purple features. Different temperatures had different influences on the copigmentation reactions. The destruction of the copigmentation complexes can result in the hypsochromic shift of the reaction solution when the temperature was higher than 20°C. The bathochromic shift of the solution gradually progressed with the increase of the pH value. A significant copigmentation feature was spotted when pH reached 3.0, which demonstrates obvious red-purple characterization. The addition of the ethanol weakened the copigmentation effect. According to measurement through color analysis, it was found that the color differences caused by ethanol in red wine were typically attributed to quantitative changes. Remarkably, all of the above delicate color deviations caused by the structural or environmental factors can be precisely and conveniently depicted via the CIELAB space analysis.

Asunto(s)

RESUMEN

Activated carbon (AC) could be a solution to remove 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) off-flavours from Dekkera/Brettanomyces contaminated red wines. The relation between AC physicochemical characteristics and removal efficiency of these compounds is unknown. The impact of ACs characteristics on 4-EP and 4-EG removal, phenolic and headspace aroma composition was studied. All ACs reduced significantly 4-EP and 4-EG levels (maximum 73%). Their efficiency was related to their surface area and micropores volume. A higher surface area of mesopores and total pore volume were detrimental for anthocyanins and colour intensity, while a higher surface area and micropores volume were important for removing phenolic acids. Volatile phenols reduction was more important for the positive fruity attribute perception than the abundance of headspace aroma compounds. With an optimal selection of the AC physicochemical characteristics it was possible to remove efficiently the volatile phenols without impacting negatively on the wine sensory quality.

Asunto(s)

RESUMEN

Data in this article presents the changes on phenolic compounds, headspace aroma composition and sensory profile of a red wine spiked with 4-ethylphenol and 4-ethylguaiacol and treated with seven activated carbons with different physicochemical characteristics, namely surface area, micropore volume and mesopore volume ("Reduction of 4-ethylphenol and 4-ethylguaiacol in red wine by activated carbons with different physicochemical characteristics: impact on wine quality" Filipe-Ribeiro et al. (2017) [1]). Data on the physicochemical characteristics of the activated carbons are shown. Statistical data on the sensory expert panel consistency by General Procrustes Analysis is shown. Statistical data is also shown, which correlates the changes in chemical composition of red wines with the physicochemical characteristics of activated carbons used.

RESUMEN

In this study, the prefermentative addition of gallic acid in Cabernet Sauvignon red winemaking was performed. The influence of gallic acid addition on wine phenolic composition, the ratio of copigmentation, and the color parameters were monitored throughout the winemaking process. The results showed that the prefermentative addition of gallic acid enhanced the extraction of total anthocyanins and the copigmentation effect, producing wines with more darkness, redness, yellowness, and saturation. Moreover, the addition of gallic acid contributed to the concentration of total phenolic acids. However, it had a negative effect on the concentrations of flavonols and flavan-3-ols in the final wines. Thus, the prefermentative addition of gallic acid at appropriate levels might be a promising enological technology to obtain wines with high color quality and aging potential.

Asunto(s)

RESUMEN

Copigmentation was investigated in model solutions between the anthocyanin malvidin-3-O-glucoside and three phenolic aldehydes (vanillic, syringic and coniferyl aldehydes) as a function of the pH and the pigment/copigment molar ratio. Tristimulus colorimetry was applied to evaluate the chromatic variations induced by copigmentation process. The results indicated that the greatest magnitude of copigmentation was obtained at pH 3.0 and molar ratio of 1:100, being significantly higher with coniferyl aldehyde, followed by syringic and vanillic aldehydes. The equilibrium constant (K) and Gibbs free energies (ΔG°) determined here show a spontaneous exothermic reaction. Theoretical calculations (ΔGbinding, ΔE) specified the relative arrangement of the pigment and copigment molecules within the complexes. In addition, an atoms in molecules (AIM) analysis was used to explore the main driving forces contributing to the formation of copigmentation complexes.

Asunto(s)

RESUMEN

Phenolic compounds determine the color quality of fruit wines. In this study, the phenolic compound content and composition, color characteristics and changes during 6 months of bottle aging were studied in wines fermented with bog bilberry syrup under three different pHs. The total anthocyanins and total phenols were around 15.12-16.23 mg/L and 475.82 to 486.50 mg GAE/L in fresh wines and declined 22%-31% and about 11% in bottle aged wines, respectively. In fresh wines, eight anthocyanins, six phenolic aids and 14 flavonols, but no flavon-3-ols were identified; Malvidin-3-O-glucoside, petunidin-3-O-glucoside and delphinium-3-O-glucoside were the predominant pigments; Chlorogentic acid was the most abundant phenolic acid, and quercetin-3-O-galactoside and myricetin-3-O-galactoside accounted for nearly 90% of the total flavonols. During 6 months of bottle storage, the amounts of all the monomeric anthocyanins and phenolic acids were reduced dramatically, while the glycosidyl flavonols remained constant or were less reduced and their corresponding aglycones increased a lot. The effects of aging on blueberry wine color were described as the loss of color intensity with a dramatic change in color hue, from initial red-purple up to final red-brick nuances, while the pH of the fermentation matrix was negatively related to the color stability of aged wine.

Asunto(s)