Search Results (46)

Dry-farmed vineyards of Vitis vinifera L. cv. País in central–southern Chile represent one of the oldest viticultural systems in the Americas; however, objective compositional evidence supporting valley-scale typicity remains limited. This single-vintage study evaluated whether dry-farmed País wines from the Maule and Itata valleys exhibit compositional and sensory differences under standardized winemaking conditions. Ten monovarietal wines (2018 vintage; n = 5 per valley) were produced by controlled microvinification and analysed for general chemistry, phenolic composition, polysaccharides, chromatic attributes (CIELAB), and volatile compounds (SPME–GC–MS), together with descriptive sensory analysis by a trained panel. Total phenols (~1.2 g GAE L⁻¹), anthocyanins (~130 mg malvidin-3-glucoside equivalents L⁻¹), and tannins were low and comparable between valleys. However, differences were observed in specific compositional domains: Maule wines showed higher flavanols, polysaccharides, and aldehydes, whereas Itata wines exhibited higher ester levels. Sensory evaluation revealed differences in colour intensity, floral aroma, retronasal red-fruit notes, and astringency. Multivariate analysis (PCoA) revealed a structured but partial separation between valleys; however, this pattern was not supported by PERMANOVA, indicating limited statistical evidence for multivariate differentiation. These findings, based on a single vintage, suggest subtle compositional and sensory differences rather than strong valley-level typicity. Full article

The aim of this study was to assess the energy potential of woody grapevine (Vitis vinifera L.) shoots depending on the cultivation system, cultivar, and fruit colour. Field studies were conducted in 2024 at the Mendel University Vineyard in Lednice (Czech Republic) on Chardonnay, Merlot, Riesling, and Zweigelt cultivars, cultivated using the Guyot and Cordon systems. The cultivar analysis covered both the amount of biomass produced during pruning and its energy and emission properties. Laboratory tests of the energy potential of the biomass obtained were carried out at the University of Life Sciences in Lublin. The results showed that the varietal factor significantly influenced the biomass parameters—Chardonnay was characterised by the highest total plant weight (773.57 g), while Zweigelt (8.60 pcs.) had the highest number of shoots with the lowest unit weight (74.82 g). The Cordon system generated significantly higher biomass yields and more favourable combustion properties compared to Guyot. Differences in fruit colour indicate that, among the studied cultivars, white-berried varieties produce heavier shoots, whereas red varieties produce a greater number of shoots. The analysis of gas emissions showed a significant influence of the cultivar and training system, with the highest CO, CO₂, and NOx emissions recorded for the Zweigelt cultivar. The results emphasise that an integrated approach, taking into account both genotypic factors, training systems and phenotypic characteristics of the vines, is crucial for optimising the use of wine biomass as an energy source in the context of a circular economy. Full article

To reveal the characteristic physicochemical indicators of wines of different quality grades and explore their feasibility as auxiliary indicators for grading, 23 wines from the Manas subregion of Xinjiang were used as test materials. Sensory evaluation, colour difference analysis, and electronic tongue technology were employed, combined with nontargeted metabolomics and quantitative analysis, to analyze differences in phenolic compounds, colour parameters, and taste characteristics among wines of different grades. Finally, a quality evaluation model for Cabernet Sauvignon wine was constructed using partial least squares regression (PLSR). The results revealed significant differences in the L* values, a* values, and C*ab values among wines of different grades. Grade A wines presented lower L* values, higher a* values, and higher C*ab values, indicating lower brightness, deeper red tones, and higher saturation. Taste characteristic differences were primarily manifested in Grade A wines, which have higher acidity, astringency, bitterness, and richness but exhibit lower bitterness aftertaste and astringency aftertaste. The results of the quantitative analysis and correlation analysis indicate that the differences in sensory characteristics among different grades of wine stem from variations in their polyphenolic compound contents. The higher anthocyanin content in Grade A wine is associated with higher a* values; higher flavonoid content is closely related to higher astringency and bitterness values; and lower flavanol content is associated with lower bitterness aftertaste and astringency aftertaste values. The PLSR model results indicate that when sensory characteristic parameters and phenolic compound content are used as predictor variables (X) and grade is used as the response variable (Y), the PLSR model has a calibration set R² = 0.97 and a validation set R² = 0.92, the calibration set RMSE is 0.13, and the validation set RMSE is 0.25. The model demonstrates good fitting performance, establishing an objective method for evaluating wine quality that avoids evaluation errors caused by the subjective factors of winemakers and tasters. This study is the first to conduct a comprehensive evaluation of the sensory characteristic and chemical components of three grades of wine, providing data support and theoretical references for the improvement of wine quality evaluation systems. Full article

The colour evolution of malvidin-3-O-glucoside (Mv-3-O-glc) elicited by caffeic acid (CAF), (+)-catechin (CA), or syringic acid (SI) was spectrophotometrically monitored in model wine solution, modulating the malvidin-to-polyphenol molar ratio (1:1 to 1:20) and the pH (2.8–3.8). The spectral features provided the thermodynamic parameters Gibbs free energy (ΔG⁰) and equilibrium constant (K_eq), showing that the copigmentation extent is maximized at pH 3.6 and a higher molar ratio (1:20), and that copigments have different efficiency. In a long-term evolution (12 months), transient complexes evolved into different colour characteristics. Spectrophotometry and colorimetry (chroma C*, hue H*, and lightness L*) revealed the formation of stable pigments with peculiar orange-reddish colour when CAF was present; however, in the case of CA, an accentuated yellow tone was observed. SI showed minimum impact in the long-term evolution of Mv-3-O-glc. This study expands knowledge on oenological copigmentation, further exploring its potential implication in the colour of aged red wines. Full article

Grape pomace is the largest by-product in the oenological industry, and in recent years, there have been multiple attempts to turn it into a high-value product, such as a fining agent. However, most of these attempts have usually been conducted with low volumes of wine, and/or in static conditions, using a long contact time between the fibre and wine. To speed up the fining process, this study evaluated the effectiveness of three pomace fibres and a commercial fibre in improving the safety of a young red wine, previously contaminated with ochratoxin A, histamine, and various pesticides, using a continuous filtration system. All the pomace fibres were capable of reducing the OTA concentration by around 50%, and one of the tested fibres exhibited a strong ability to decrease most of the pesticides present in the wine, with the results being even better than when this fibre was used in static conditions. All the tested fibres similarly reduced the tannin concentration of the wines, without having a major impact in the colour index. These results prove that pomace grape fibres are an effective fining agent suitable for use in a continuous filtration system, allowing for a reduction in the fining time from days to hours. Full article

The Tempranillo grape variety is the most widely cultivated red grape cultivar in Spain. However, it has been observed that this variety may not always exhibit the optimal colour properties in warm climates such as Andalusia (southern Spain). Several strategies have been proposed to enhance productivity and resilience to stress or improve the quality of both grapes and wines. The foliar application of agricultural plant extracts has been identified as a highly effective method of promoting the synthesis of secondary metabolites in the grapevine. The objective of the current research was to analyse the incidence of foliar application of different extracts from winemaking by-products (grape stems: GS, grape pomaces: GP and wine lees: WL) on Tempranillo grapevine leaves, studying the impact on the quality of the resulting wines. The oenological and colour characteristics of the wines were assessed to evaluate the impact of these extracts on wines during the winemaking process. The detailed composition of the wines revealed that GS and WL extracts led to significant differences in wine colour properties. Wines derived from grapes treated with both extracts exhibited heightened colour intensity, accompanied by discernible alterations in CIELab coordinates, with lower L* and higher a* and C*ab values in comparison to CT. These results are encouraging, and the foliar application of GS extracts at veraison appears to be a feasible alternative to enhance the colour of wines from red grape cultivars with colour difficulties in warm climates. Full article

Underwater aging of alcoholic beverages has gained growing interest in recent years as a novel strategy for product differentiation. This study investigated the effects of 12 months of underwater aging at 13 m depth on the chemical, volatile, and phenolic profiles of wine-based liqueurs, compared to traditional cellar aging. Individual bottles were analysed using an E-nose, achieving 96% correct classification in the cross-validated confusion matrix. Chemical analysis revealed no significant differences in pH, ethanol content, total and volatile acidity. Although total phenolic content did not differ significantly, underwater-aged liquors exhibited higher levels of anthocyanins, suggesting reduced degradation of phenolic compounds in the anaerobic underwater environment. This was supported by higher levels of free alpha-amino nitrogen and total proteins, suggesting slower oxidation. As a result, underwater-aged liquors showed a lower b* index (yellowness), likely due to the reduced oxidation of red colour compounds. Underwater aging induced some changes in the volatile profile, with a significant increase in certain furanones and pyranones, such as 5-hydroxymethylfurfural, 4-hydroxydihydro-2-(3H)-furanone and 3,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one, responsible for strawberry, toasted, and caramel notes. This increased production could be attributed to the unique underwater environment, characterised by oscillating vibrations, blue-green light, lower and more constant temperatures and reduced oxygen levels. Full article

Anthocyanins are important bioactive compounds crucial for the sensory characteristics of red wines. Anthocyanin profiles of 205 monovarietal red wines from the Canary Islands were investigated. Eleven anthocyanins were identified and determined using HPLC-DAD. Anthocyanin concentrations of red wines produced in Canary Islands fell within the usual range observed in red wines from other regions. Red wines elaborated with international grape cultivars presented, in general, higher mean concentrations than those elaborated using autochthonous cultivars. The influence of grape cultivar, production island, denomination of origin, and wine aging on the anthocyanin concentration was studied, leading to the deduction that aging was the parameter with the highest influence. A high number of significant correlations between the anthocyanins determined were found out supporting a common organic synthetic way for these coloured phenolics. Application of multivariate analysis techniques, such as principal component analysis and discriminant analysis, tended to classify the red wine samples according to grape cultivar, geographical production areas, and aging. This study could contribute to the quality control and verification within the wine industry, which is an interesting tool in the prevention of fraud and for increasing consumer confidence. Full article

This study evaluates the effect of protein hydrolysates, obtained from grape seed meal (industrial waste), as colour stabilisers in red wines from warm climates. Protein hydrolysates were added to the wine after fermentation and maceration. Assays were performed using different types and doses of protein hydrolysates. Two grapevine-growing seasons were monitored over 8 months. Attention was focused on different families of polyphenolic compounds, copigmentation, and polymerisation, and colour changes were assessed by differential tristimulus colourimetry. Regardless of doses and typology, wines with protein hydrolysates suffered a decrease in the amount of phenolics and an increase in % polymerisation. Only wines treated with 3 g/L of hydrolysates showed lower colour intensity and greater clarity and hue after 8 months, while treatment with 0.5 g/L produced brownish wines. The addition of hydrolysates from a low hydrolysis time did not affect the copigmentation balances or produced negative visually perceptible colour differences over time. These results indicate that the post-fermentation addition of protein hydrolysates does not seem to significantly improve the stabilisation of the wine colour, in contrast to the addition at other stages. This information is of great interest to wineries to consider the application of this novel technique at the optimal time. Full article

Wine ageing represents an important stage during wine production when the final wine composition is formed. In this study, 2020 and 2021 vintage Merlot red wines were subjected to 12-month ageing in a stainless-steel tank, Excellence oak barrels with medium, medium-plus and medium-long toasting, and a Premium oak barrel with medium toasting. The aim was to investigate the influence of different ageing vessels on the main chemical composition, element content, phenolic profile, antioxidant activity, and wine colour during ageing. The results showed that changes in ethanol, total sugars, pH, and density were minimal, mostly not significant. Slight changes in malic and lactic acid concentration occurred due to malolactic fermentation. Statistically, more changes that are significant occurred in the phenolic profile, and they affected the antioxidant activity of the wine. In both wine vintages, anthocyanin content decreased, followed by an increase in polymeric colour. Elements and individual phenolic compounds changed significantly, depending on vessel type, ageing time, wine vintage, and initial concentrations. The PCA biplots of the mentioned compounds showed that vessel type had a significant influence on wine composition, especially after 12 months of ageing. According to the CIELab parameters, a slight colour change occurred in both wine vintages, but this is not visible to the human eye. According to the obtained results, various changes in the phenolic profile of Merlot wine occurred during ageing, which strongly depended on the ageing vessel used, the ageing time, and the initial wine composition. Full article

Background: Thermovinification is a non-conventional winemaking practice that replaces the traditional method of grape maceration. Methods: This study evaluated the influence of thermovinification temperature on the quality of Syrah wines. The treatments included traditional winemaking with 7 days of maceration during alcoholic fermentation at 23 °C (TW—control); and thermovinification for 2 h at 55 °C (TV55), 65 °C (TV65), and 75 °C (TV75). The red wines were made through microvinification (10-litre glass). Phenolic compounds (n = 26) were quantified by high-performance liquid chromatography and a colour analysis using the CIELab/CIEL*C*h systems and a sensory analysis was conducted to evaluate the acceptability of the thermovinified wine. Results: The results indicate that thermovinification increased the content of bioactive compounds and intensified the colour of the wine, reducing L* and a*. However, the content of phenolic acids decreased, except for trans-caftaric acid, which was approximately 50 times higher. A higher temperature of thermovinification (75 °C) promoted the degradation of all anthocyanins. Among flavonols, kaempferol-3-O-glucoside, quercetin-3-β-D-glucoside, and isorhamnetin-3-O-glucoside were higher in TV65 and TV75 wines. Greater amounts of stilbenes were quantified in TV65. Among the flavan-3-ols, TV75 stood out, especially for (+)-catechin, (−)-epicatechin, procyanidin A2, and procyanidin B1. Conclusions: The thermovinification at 65 °C is optimal for minimising anthocyanin degradation and improving Syrah wine quality. Full article

The utilisation of non-Saccharomyces yeasts in co-inoculation and non-thermal technologies for must sterilisation is becoming increasingly prevalent due to their notable utility and potential. This new approach optimises the fermentation process and contributes to facilitating the production of wines with distinctive characteristics, improving their stability, and without organoleptic repercussions. Two trials were conducted concurrently, designated as A and B, using the same Tempranillo red must. In each trial, UHPH-treated and untreated must (serving as the control) were compared. The non-Saccharomyces yeasts (Lachancea thermotolerans and Metschnikowia pulcherrima) were identical in both trials, and fermentations were terminated by a Saccharomyces cerevisiae inoculated after 7 days (ternary fermentation). In Trial A, different percentages of the initial inoculum were employed with respect to the total volume that must be fermented, with the objective of evaluating the influence and competitiveness between yeasts. Trial B was designed to investigate the impact of two nutrients that provide vitamins, energy, and protection from oxidative stress on the development of these yeasts and their metabolic expression. Microbiological analysis and measurements of oenological parameters were carried out, acidification was assessed, volatile compounds were analysed, and the colour spectrum was measured by spectrophotometry. It was observed in both trials that the prevalence of Lachancea thermotolerans (Lt) was longer than that of Metschnikowia pulcherrima (Mp) and that the use of quercetin + thiamine had a positive effect on yeast growth. Furthermore, the combination of Lt and Mp yeasts demonstrated remarkable synergy, resulting in the production of a substantial quantity of lactic acid (>5 g/L). With regard to aroma compounds, the UHPH must have exhibited a nearly twofold increase in ethyl lactate. Additionally, the total polyphenol index (TPI) was observed to be 8–10% higher in wines derived from UHPH musts, indicating that this technology may potentially safeguard against oxidation. Full article

Polyphenols are responsible for wine colour and astringency, and, as antioxidants, they also have beneficial health properties. In this work, we developed a robust full-scan high-resolution mass spectrometry method for the quantification of 90 phenolic compounds in wine samples (either red, rosé, or white wine), using a UHPLC-Orbitrap^TM system. With this method, we could conduct a detailed analysis of phenolic compounds in red, rosé, and white wines with great selectivity due to sub-ppm mass accuracy. Moreover, accessing the full-scan spectrum enabled us to monitor all the other compounds detected in the sample, facilitating the adaptability of this method to new phenolic compounds if needed. Full article

Sulphur dioxide (SO₂) is usually used in winemaking due to its effectiveness as an antimicrobial and antioxidant agent. However, there is growing interest in finding alternatives to SO₂ because of its adverse effects on human health. Therefore, in this work, a low-SO₂-producing Saccharomyces cerevisiae strain was selected and the AIR-MIXINGTM M.I^TM (A.M.) system, capable of determining a high extraction of polyphenols, was used to produce a red wine without added sulphites. A tank managed with the traditional pumping-over technique was used as a comparison. Microbiological and chemical monitoring of both fermentations performed by plate counts and HPLC analyses, respectively, did not indicate significant differences as regards the yeast growth kinetics and the degradation of the sugars, while it highlighted a faster extraction kinetics of colour and total polyphenols in the fermentation carried out with the A.M. system. Both experimental wines showed a total SO₂ content <10 mg/L, but in the wine produced with A.M., a higher content of the polymeric forms of anthocyanins and non-anthocyanin phenols was found in favour of a higher stability of the wine achieved in a shorter time than the control. Furthermore, a higher concentration of reduced glutathione, a compound well-known for its antioxidant activity, occurred in wine obtained with the A.M. system. In conclusion, the use of low-SO₂-producing yeasts in combination with the A.M. system could be a suitable approach to produce wines without sulphites added. Full article

The elemental composition of wine is influenced by endogenous sources and interventions from winemakers. The ICP-MS analysis of Fruška Gora wines (113) from vintages spanning across a decade (2011–2020), produced by 30 wineries and representing 18 autochthonous and international wine varieties, allowed a comprehensive insight into their elemental composition. Based on the mean concentrations of 23 investigated elements, B, Fe, and Mn, which were determined in mg per L of wine regardless of its colour or origin, were the most abundant. Red and white wines showed significant concentration differences in the case of B, Mn, and Sr (higher in red) as well as Be, Al, V, As, Mo, and Pb (higher in white). The elements of the highest toxicological concern were found in all (Pb and As) or almost all of the samples (Cd and Hg). Pb levels (maximum 47.1, 61.6, and 73.2 μg/L in red, rose, and white, respectively) were well below the legal limit. The applied risk assessment approaches (hazard quotient and index, margin of exposure) revealed no health concerns associated with consumption of Fruška Gora wines, except for a slightly increased lifetime cancer risk in the case of high wine consumption, and thus supported the promotion of Fruška Gora wines in the highly competitive international market. Full article