Search Results (38)

The production of winter wines in Southeastern Brazil represents a relatively recent but expanding viticultural approach, with increasing adoption across diverse wine-growing regions. This system relies on the double-pruning technique, which allows for the harvest of grapes during the dry and cooler winter season, favoring a greater accumulation of sugars, acids, and phenolic compounds. This study aimed to characterize the phenological stages, thermal requirements, yield, and fruit quality of the fine wine grape cultivars ‘Sauvignon Blanc’, ‘Merlot’, ‘Tannat’, ‘Pinot Noir’, ‘Malbec’, and ‘Cabernet Sauvignon’ under double-pruning management in a subtropical climate. The vineyard was established in 2020, and two production cycles were evaluated (2022/2023 and 2023/2024). Significant differences in the duration of phenological stages were observed among cultivars, ranging from 146 to 172 days from pruning to harvest. The accumulated thermal demand was higher in the first cycle, with a mean of 1476.9 growing degree days (GDD) across cultivars. The results demonstrate the potential of Vitis vinifera L. cultivars managed with double pruning for high-quality wine production under subtropical conditions, supporting the viability of expanding viticulture in the state of São Paulo. ‘Cabernet Sauvignon’ and ‘Sauvignon Blanc’ showed the highest yields, reaching 3.03 and 2.75 kg per plant, respectively, with productivity values of up to 10.8 t ha⁻¹. ‘Tannat’ stood out for its high sugar accumulation (23.4 °Brix), while ‘Merlot’ exhibited the highest phenolic (234.9 mg 100 g⁻¹) and flavonoid (15.3 mg 100 g⁻¹) contents. These results highlight the enological potential of the evaluated cultivars and confirm the efficiency of the double-pruning system in improving grape composition and wine quality in non-traditional viticultural regions. Full article

Sustainable viticulture practices could be useful tools for ensuring grape and wine quality, especially in the context of climate change. A promising and innovating approach is the use of bioelicitors in order to stimulate productivity and metabolite biosynthesis in an environmentally friendly way. However, the result depends on the variety, the phenological stage, concentration of the biomolecule applied, and climate conditions. The present study examined the impact of the plant hormone abscisic acid on the phenolic compound accumulation in the autochthonous, red-colored Greek grapevine variety Mouhtaro. During 2018 and 2019 vintages berry quality characteristics, and metabolome were evaluated at three stages: véraison, beginning and mid, and harvest. Abscisic acid (ABA) was given at doses of 0.04% w/v and 0.08% w/v during the véraison stage. According to the results, the ABA-treated grape berries were smaller and exhibited lower total soluble solid levels and increased titratable acidity compared to the control. Although no significant differences were observed in amino acids or anthocyanin and stilbene accumulation upon ABA treatment, application of ABA at the higher dose resulted in increased concentrations of phenolic acids, flavan-3-ols, and flavonols. Therefore, the application of ABA could be considered as a promising method for improving the grape quality characteristics of Mouhtaro. Full article

Demonstrating the authenticity and traceability of quality wines based on parameters that reflect their composition and provenance contributes to protecting wine authenticity and to increasing consumer confidence in moderate wine consumption, which is associated with numerous health-promoting properties. A wine’s phenolic fingerprint is increasingly used to assess its authenticity, even though wine phenolic composition is influenced by genetic and environmental factors, as well as vineyard management and enological practices, and storage conditions. This study presents a comprehensive analysis of the bioactive characteristics (total polyphenols—TPs, total flavonoids—TFs, antioxidant activity—AA, and total anthocyanins—TAs) by spectrophotometric analysis and phenolic compound profile (by UHPLC-HRMS analysis) of 19 white and 21 red wines with a Protected Designation of Origin (PDO) from four vineyards located in the wine-growing region of Oltenia, Romania. Multivariate statistical analysis, specifically principal component analysis and heat map analysis, applied to analytical data, enables the discrimination of wines based on grape variety and terroir, and across four consecutive vintages (2019–2022). The phenolic profiles of the wines obtained under standardized winemaking conditions depend on the climatic data specific to each harvest year (temperature, precipitation, duration of sun exposure during grape berry phenological stages, and ripening). The phenolic biomarkers of red wines, such as epicatechin, catechin, gallic, caffeic, t-ferulic acids, t-resveratrol and hesperidin, represent specific biomarkers of warmer and sunnier harvest years with lower precipitation, as observed in the 2021 harvest year. Additionally, our results contribute to the identification of specific phenolic biomarkers for geographical and varietal discrimination, as well as to the promotion of high-quality wines produced in a renowned wine-growing region of Romania. Full article

Traditional winter pruning in dormancy (BBCH-00) as control (C) and three late pruning treatments, LP1 (wool stage—BBCH-05), LP2 (two leaves folded—BBCH-12), and LP3 (four leaves folded—BBCH-14), were applied on Kékfrankos grapevines. The evolution of the phenological growth stages, grape juice, wine analytical parameters, and phenolic composition were evaluated. The quantitative aspects of the grape berry, bunch, yield, and cane were also assessed. Our goal was to reach a decrease in sugar content and an increase in acidity. Delaying or postponing the phenological phases to bring technological and phenolic ripening closer together was also one of our objectives. These were accomplished, but the negative aspects of late pruning, which resulted in a reduction in the diameter and weight of the canes, should also be taken into account. We also found that, the later the late pruning, the more the yield was reduced. By postponing pruning, the phenological phases were also extended. Full article

High-altitude and cold climate regions such as São Joaquim, in Santa Catarina, Brazil, a recent wine-growing region, are characterized by wines with pronounced acidity, ideal for sparkling wine production. The cultivars with potential for producing sparkling wines in this region were unknown. This research evaluates quality sparkling wines from Ribolla Gialla, Riesling Renano, Solaris, Sangiovese, Canaiolo Nero, Chardonnay, and Pinot Noir. The study considered the phenological, productive, and qualitative performance of these varieties in the 2017/2018 and 2018/2019 seasons. Ribolla Gialla, Riesling Renano, and Sangiovese, with later bud break and better productive aspects, are the best viticultural adaptations for the region. Riesling Renano maintains higher acidity. Sparkling wines from Solaris, Chardonnay, and Ribolla Gialla showed the most balanced chemical parameters. Sangiovese produced sparkling wine with the highest aroma intensity and toasted notes. Considering phenological, productive, and qualitative parameters, Riesling Renano, Ribolla Gialla, and Sangiovese are the most promising varieties for sparkling wine production in São Joaquim. Quality sparkling wines can be produced in this region using varieties different from those traditionally used in Brazil, enhancing the diversity of Brazilian viticulture. Full article

In Mexico, viticulture represents the second source of employment in the agricultural area after the fruit and vegetable sector. In developed countries, remote sensing is widely used for vineyard monitoring; however, this tool is barely used in the developing countries of Iberoamerica. In this research, our overall objective is to characterise two vineyards in the state of Queretaro (Mexico) using Sentinel-2 and meteorological data, specifically spectral and thermal indices. Results show that spectral indices obtained from Sentinel-2 bands have adequately characterised the phenological dynamics of the different varieties of the vineyards. The Modified Soil-Adjusted Vegetation Index (MSAVI) was adequately used to discriminate between the first stages of vineyards, while the Normalized Difference Vegetation Index (NDVI) was useful for monitoring vineyards during the rest stages of vineyards. Thermal indices have shown that the best grape varieties are those that can adapt to both cooler and warmer temperatures, have a reasonable ripening period, and can produce wines with balanced acidity and flavours. In conclusion, the combination of meteorological (including thermal indices) and remote sensing data (NDVI and MSAVI) provide information for choosing a suitable grape variety for this region. Full article

As a result of climate change, the phenology of grapes has been altered, mainly by increasing the sugar content and decreasing the acidity of ripe grapes. This shift, when the must is fermented, affects the quality of the wine. In this regard, the use of selected Saccharomyces and non-Saccharomyces yeasts to mitigate these undesirable effects in wine fermentations entails new strategies to improve their control and also to obtain wines better adapted to current consumer preferences. This work focuses on the use of a commercially available strain of Lachancea thermotolerans immobilized in biological support to form “microbial biocapsules”, comparing its effect with a free format and spontaneous fermentation on alcoholic fermentation and volatile compound composition. These biocapsules, consisting of yeast cells attached to fungal pellets, are being tested to improve wine sensory attributes and also to facilitate yeast inoculation in fermentative and clarification winemaking processes, as well as to reduce time and production costs. The composition of young wines obtained with L. thermotolerans, inoculated as free or biocapsule formats, were compared with those obtained by the traditional method of spontaneous fermentation using native yeast by quantifying 12 oenological variables and the contents in 12 major volatiles, 3 polyols, and 46 minor volatile compounds. The analytical data matrix underwent statistical analysis to compare and establish significant differences at p ≤ 0.05 level between the different wines obtained. Among the major volatiles and polyols, only ethyl acetate, 1,1-diethoxyethane, methanol, 2-methyl-1-butanol, acetoin, ethyl lactate, and glycerol showed significant differences in L. thermotolerans wines. Also, from the minor volatile metabolites, eight showed a significant dependence on the format used for L. thermotolerans, and the other nine volatiles were dependent on both yeast and inoculation format. Only 27 volatiles were selected as aroma-active compounds with odor activity values higher than 0.2 units. Statistical analysis showed a clear separation of the obtained wines into groups when subjected to Principal Component Analysis, and the fingerprinting of wines made with biocapsules shows intermediate values between the two remaining inoculation formats, particularly in the fruity/ripe fruit, green, and floral series. The organoleptic evaluation of wines results in significantly higher values in taste, overall quality, and total score for wines obtained with biocapsules. Full article

Green leaf volatiles (GLVs) are important in giving grape a fresh and green aroma. But the changes in GLVs during the phenological development of grapevines are not well known. This study analyzed the GLVs and transcription levels of associated biosynthetic genes in six grape species from the Loess Plateau region at five stages of maturation. Thirteen GLVs were detected, showing unique patterns for each grape type at various growth phases. The primary components in six grapes were (E)-2-hexenal, (E)-2-hexen-1-ol, and hexanal. With the exception of Cabernet Franc in 2019, the overall GLV contents of the six types generally increased during growth and development, peaking or stabilizing at harvest. And Sauvignon Blanc, Cabernet Gernischt, and Cabernet Sauvignon exhibited higher total contents among the varieties. PLS-DA analysis revealed 3-hexenal’s high VIP scores across two years, underscoring its critical role in grape variety classification. Correlation analysis revealed a strong positive correlation between the levels of hexanal, 1-hexanol, (E)-2-hexen-1-ol, (Z)-3-hexenyl acetate, nonanal, and (E, E)-2,6-nonadienal and the expression of VvHPL and VvAAT genes in the LOX-HPL pathway. Specifically, VvHPL emerges as a potential candidate gene responsible for species–specific differences in GLV compounds. Comprehending the changing patterns in the biosynthesis and accumulation of GLVs offers viticulturists and enologists the opportunity to devise targeted strategies for improving the aromatic profile of grapes and wines. Full article

In this study, a total of 34 Spanish minority varieties were studied during four seasons from 2020 to 2023, and their behavior was characterized according to their main phenological stages (bud break, bloom, veraison, and maturity) and complete cycle. We focused on the varieties prospected in the central Spanish plateau and conserved in the “El Encín” grapevine collection, aiming to identify the potential for adaptation of these varieties and for them to be considered by winegrowers as an alternative to current climate change conditions. The growing degree days required for the expression of the phenological stage, and the duration of each stage, were compiled. Characteristics of oenological interest were also monitored, such as °Brix, pH, and titratable acidity in must at the time of harvest. This study was carried out in years with atypical snowfall and cold spells (winter 2021), as well as with heat waves (summer 2022), with average temperatures 3–5 °C higher than normal and absolute maximum temperatures over 40 °C. Both cases also exceeded records of historical series (1957–2019). Veraison has been identified as the stage most susceptible to damage from high temperatures, in addition to the maturation and duration of the complete cycle. The varieties were classified into five groups according to the duration of each phenological stage (very early, early, medium, late, and very late). Some varieties with late or very late maturation and with must characteristics of 20–23 °Brix, 3–5 g/L of titratable acidity, and pH 3.5–4.5, as well as others, retained stability in their phenological periodicity and must quality. The results suggest that special attention should be given to thoroughly evaluating these varieties, and that the strategies contemplated should be considered as a feasible cultivation alternative in viticulture to mitigate the effects of climate change. Full article

In the pursuit of enhancing the wine production process through the utilization of new technologies in viticulture, this study presents a novel approach for the rapid assessment of wine grape maturity levels using non-destructive, in situ infrared spectroscopy and artificial intelligence techniques. Building upon our previous work focused on estimating sugar content (${}^{\circ }$Brix) from the visible and near-infrared (VNIR) and short-wave infrared (SWIR) regions, this research expands its scope to encompass pH and titratable acidity, critical parameters determining the grape maturity degree, and in turn, wine quality, offering a more representative estimation pathway. Data were collected from four grape varieties—Chardonnay, Malagouzia, Sauvignon Blanc, and Syrah—during the 2023 harvest and pre-harvest phenological stages in the vineyards of Ktima Gerovassiliou, northern Greece. A comprehensive spectral library was developed, covering the VNIR–SWIR spectrum (350–2500 nm), with measurements performed in situ. Ground truth data for pH, titratable acidity, and sugar content were obtained using conventional laboratory methods: total soluble solids (TSS) (${}^{\circ }$Brix) by refractometry, titratable acidity by titration (expressed as mg tartaric acid per liter of must) and pH by a pH meter, analyzed at different maturation stages in the must samples. The maturity indicators were predicted from the point hyperspectral data by employing machine learning algorithms, including Partial Least Squares regression (PLS), Random Forest regression (RF), Support Vector Regression (SVR), and Convolutional Neural Networks (CNN), in conjunction with various pre-processing techniques. Multi-output models were also considered to simultaneously predict all three indicators to exploit their intercorrelations. A novel multi-input–multi-output CNN model was also proposed, incorporating a multi-head attention mechanism and enabling the identification of the spectral regions it focuses on, and thus having a higher interpretability degree. Our results indicate high accuracy in the estimation of sugar content, pH, and titratable acidity, with the best models yielding mean $R^2$ values of 0.84, 0.76, and 0.79, respectively, across all properties. The multi-output models did not improve the prediction results compared to the best single-output models, and the proposed CNN model was on par with the next best model. The interpretability analysis highlighted that the CNN model focused on spectral regions associated with the presence of sugars (i.e., glucose and fructose) and of the carboxylic acid group. This study underscores the potential of portable spectrometry for real-time, non-destructive assessments of wine grape maturity, thereby providing valuable tools for informed decision making in the wine production industry. By integrating pH and titratable acidity into the analysis, our approach offers a holistic view of grape quality, facilitating more comprehensive and efficient viticultural practices. Full article

Leaf removal is a cultural practice mainly aimed at improving cluster zone microclimates and impacting primary and secondary metabolites, such as volatiles. This research aimed to assess the impact of defoliation on free and glycosylated aromas of a neutral (‘Nebbiolo’) and a semi-aromatic (‘Aleatico’) red variety. Defoliation was performed at fruit set (BBCH 71) and, for ‘Nebbiolo’, also at berries touch (BBCH 81) phenological stages. Skins and pulps were separately analyzed by Solid Phase Extraction–Gas Chromatography/Mass Spectrometry. Results showed that the response to defoliation was variety-dependent. For ‘Nebbiolo’, especially when performed at the berries’ touch stage, defoliation had a significant effect on the accumulation of free volatiles and glycosidic precursors. Differently, free and bound ‘Aleatico’ volatiles were less impacted by defoliation. Interestingly, in both grapevine varieties, defoliation significantly enhanced the accumulation of aroma precursors in grapes’ skins, which is of particular relevance for red wine production and their aging potential. Moreover, results could be helpful for the management of grape quality, as defoliation is currently considered as a strategy to address climate change issues. Full article

Climate change is a critical challenge for the global grape and wine industry, as it can disrupt grapevine growth, production, and wine quality. Climate change could influence the cost-effectiveness and growth of the wine industry in different wine regions since grapevine development is deeply dependent on weather (short-term) and climate (long-term) conditions. Innovation and new technologies are needed to meet the challenge. This review article addresses the impact of climate change on grapevines, such as vine phenology, pest and disease pressure, crop load, and grape and wine composition. It also reviews recent advances in the areas of viticultural manipulation and relevant technologies to potentially reduce the impact of climate change and help growers improve grape quality. Remote sensing is used for vineyard microclimate monitoring; thermal sensors combined with UAVs, aircraft, or satellites are used for water management; soil electrical conductivity sensors have been developed for soil mapping. Viticultural manipulations, such as regulated deficit irrigation for water use efficiency and berry-ripening delay for growing quality fruit, are also discussed. The review assesses future directions for further technological development, such as soil and vine water monitoring devises, precision viticulture, and artificial intelligence in vineyards. Full article

Climate change and compostinS1g methods have an important junction on the phenological and ripening grapevine phases. Moreover, the optimization of these composting methods in closed-loop corporate chains can skillfully address the waste problem (pomace, stalks, and pruning residues) in viticultural areas. Owing to the ongoing global warming, in many wine-growing regions, there has been unbalanced ripening, with tricky harvests. Excessive temperatures in fact impoverish the anthocyanin amount of the must while the serious water deficits do not allow a correct development of the berry, stopping its growth processes. This experiment was created to improve the soil management and the quality of the grapes, through the application of a new land conditioner (Zeowine) to the soil, derived from the compost processes of industrial wine, waste, and zeolite. Three treatments on a Sangiovese vineyard were conducted: Zeowine (ZW) (30 tons per ha), Zeolite (Z) (10 tons per ha), and Compost (C) (20 tons per ha). During the two seasons (2021–2022), measurements were made of single-leaf gas exchange and leaf midday water potential, as well as chlorophyll fluorescence. In addition, the parameters of plant yield, yeast assimilable nitrogen, technological maturity, fractionation of anthocyanins (Cyanidin-3-glucoside, Delphinidin-3-glucoside, Malvidin-3-acetylglucoside, Malvidin-3-cumarylglucoside, Malvidin-3-glucoside, Peonidin-3-acetylglucoside, Peonidin-3-cumarylglucoside, Peonidin-3-glucoside, and Petunidin-3-glucoside), Caffeic Acid, Coumaric Acid, Gallic Acid, Ferulic Acid, Kaempferol-3-O-glucoside, Quercetin-3-O-rutinoside, Quercetin-3-O-glucoside, Quercetin-3-O-galactoside, and Quercetin-3-O-glucuronide were analyzed. The Zeowine and zeolite showed less negative water potential, higher photosynthesis, and lower leaf temperature. Furthermore, they showed higher levels of anthocyanin accumulation and a lower level of quercetin. Finally, the interaction of the beneficial results of Zeowine (soil and grapevines) was evidenced by the embellishment of the nutritional and water efficiency, the minimizing of the need for fertilizers, the closure of the production cycle of waste material from the supply chain, and the improvement of the quality of the wines. Full article

Spectroscopy is a widely used technique that can contribute to food quality assessment in a simple and inexpensive way. Especially in grape production, the visible and near infrared (VNIR) and the short-wave infrared (SWIR) regions are of great interest, and they may be utilized for both fruit monitoring and quality control at all stages of maturity. The aim of this work was the quantitative estimation of the wine grape ripeness, for four different grape varieties, by using a highly accurate contact probe spectrometer that covers the entire VNIR–SWIR spectrum (350–2500 nm). The four varieties under examination were Chardonnay, Malagouzia, Sauvignon-Blanc, and Syrah and all the samples were collected over the 2020 and 2021 harvest and pre-harvest phenological stages (corresponding to stages 81 through 89 of the BBCH scale) from the vineyard of Ktima Gerovassiliou located in Northern Greece. All measurements were performed in situ and a refractometer was used to measure the total soluble solids content (°Brix) of the grapes, providing the ground truth data. After the development of the grape spectra library, four different machine learning algorithms, namely Partial Least Squares regression (PLS), Random Forest regression, Support Vector Regression (SVR), and Convolutional Neural Networks (CNN), coupled with several pre-treatment methods were applied for the prediction of the °Brix content from the VNIR–SWIR hyperspectral data. The performance of the different models was evaluated using a cross-validation strategy with three metrics, namely the coefficient of the determination ($R^2$), the root mean square error (RMSE), and the ratio of performance to interquartile distance (RPIQ). High accuracy was achieved for Malagouzia, Sauvignon-Blanc, and Syrah from the best models developed using the CNN learning algorithm ($R^2>0.8$, $\mathrm{RPIQ}\ge 4$), while a good fit was attained for the Chardonnay variety from SVR ($R^2=0.63$, $\mathrm{RMSE}=2.10$, $\mathrm{RPIQ}=2.24$), proving that by using a portable spectrometer the in situ estimation of the wine grape maturity could be provided. The proposed methodology could be a valuable tool for wine producers making real-time decisions on harvest time and with a non-destructive way. Full article

Grapevines are among the crops that could suffer stronger effects under climate change, although the effect can differ based on cultivars and location. The aim of this work was to analyse the phenological response of the Verdejo variety compared to other two white varieties (Viura and Sauvignon Blanc) cultivated in Rueda Designation of Origin (DO), Spain, under the present climate conditions, and their potential shifts under projected climate change scenarios. Phenological dates referring to budbreak, flowering, véraison and harvest were analyzed for the period 2008–2021 in 13 plots, together with the weather conditions at daily time scale recorded during the same period. The chill and heat units were evaluated to determine the starting date for heat accumulation, as well as the base temperature to reach each phenological stage. The influence of temperature (maximum and minimum) and water availability averaged for different periods between phenological events were evaluated, and the information was used to project potential changes in phenology by 2050 and 2070 under two Representative Concentration Pathway (RCP) scenarios: RCP4.5 and RCP8.5. An advance of all phenological dates was projected, in particular for véraison and ripening. Verdejo could suffer slightly higher advance than Sauvignon Blanc, and, in any case, ripening will happen under warmer conditions. By 2050, flowering could be advanced between seven and nine days, depending on the emission scenario. However, véraison could be advanced about 13 or 14 days under the RCP4.5 scenario and between 16 and 19 days under the RCP8.5 scenario. Ripening could be reached by 2050 up to 20 days and 25 days earlier, respectively, under the RCP4.5 and the RCP8.5 emission scenarios, and up to 29 days earlier by 2070. These projections may imply further impacts on grapes and wines for the aforementioned cultivars associated to harvest under warmer conditions. Full article