Search Results (1,320)

The strategic choice of training system is essential for adapting viticulture to current climate change, ensuring a balance of physiological efficiency and the sustainability of productivity and oenological quality. This study evaluated the effects of vertical shoot positioning and foldable lyre systems (set at angles of 20°, 30° and 40°) on the physiological performance and yield of ‘Merlot’ grapevines. The experiment was conducted in a humid temperate region in Brazil over two consecutive seasons. The experiment followed a randomized block design. The variables evaluated included: the number of clusters per shoot, cluster weight, pruning weight, Ravaz Index, leaf area and yield; gas exchange parameters such as net CO₂ assimilation rate, stomatal conductance, transpiration rate, rubisco carboxylation efficiency, intercellular CO₂ concentration and photosynthetic photon flux density; and chemical composition of berries such as pH, Total Soluble Solids and Titratable Acidity. The data were subjected to an analysis of variance, and the means were compared using Tukey’s test at a 5% probability level. The results indicated that canopy architecture significantly influenced solar radiation interception, with the 30° and 40° foldable lyre systems achieving the highest mean daily radiation levels, exceeding the vertical positioning system by 73.7% and 76.6%, respectively. Although gas exchange at the leaf level remained comparable across all systems, agronomic performance varied considerably. The 40° foldable lyre system achieved the highest yield (22.99 t ha⁻¹), representing a 63.1% increase over the vertical positioning system (14.10 t ha⁻¹). The number of buds in the foldable lyre systems increased by around 70%, which is closely in line with the observed increase in yield. In addition, the foldable lyre systems provided about 40% more leaf area than the vertical positioning system. These findings suggest that divided canopy systems, such as foldable lyre systems, particularly at 30° and 40°, optimize bud load, fruitfulness per shoot, light interception and significantly increase yield without compromising individual physiological efficiency and berry chemical composition, with a balance between vegetation and fruit load preserved and with positive effects on the ripeness and quality of the grapes. Full article

Raisins come from dried Vitis vinifera L. grapes. They are consumed worldwide, and their shape, color, texture, and taste largely determine consumer preference and market success. Consumers often select raisins based on visual appeal—namely color—without insight into how this relates to nutritional quality. Therefore, this study evaluated raisins of different colors based on non-targeted metabolomics to reveal the nutritional differences among differently colored raisins and to measure the differences in antioxidant capacity. Compared with green raisins (‘Sultanina’), 377–381 differential metabolites were identified in other colored varieties. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that these metabolites were enriched in pathways such as ‘biosynthesis of other secondary metabolites’ and ‘amino acid metabolism’. The comparison of the antioxidant capacity of raisins of different colors shows that the darker the color of the raisins, the stronger their antioxidant capacity. Correlation analysis between total antioxidant capacity and 14 differential metabolites showed a significant positive correlation. Notably, syringetin levels in black raisins (‘Blackcurrant’ and ‘Sweet Sapphire’) were substantially higher—148.31 and 515.94 times greater, respectively—than in green raisins (‘Sultanina’). This elevated syringetin content may significantly contribute to the enhanced antioxidant capacity of black raisins. Furthermore, based on the positive ion mode, the relative contents of 24 and 12 differential metabolites were relatively high in green and red raisins, respectively. The negative ion model identified that 19 and 4 differential metabolites had relatively high contents in green and red raisins. These metabolites may be linked to the unique health benefits of red and green raisins. This study provides valuable insights for consumers selecting raisins based on health needs and for companies developing raisin-based health products. Full article

Kyoho grape, a leading table grape variety in China, is prone to rapid postharvest deterioration due to its soft texture and high respiration rate. Despite the use of low-temperature storage and modified atmosphere packaging (MAP), systematic studies defining the optimal combination of subzero temperature and gas composition for Kyoho grapes remain lacking. This study aimed to fill this gap by evaluating the synergistic effects of subzero temperature and MAP on quality preservation. Results demonstrated that storage at −1 °C most effectively maintained fruit firmness, stem freshness, and key biochemical components. Based on this temperature, a gas composition of 3% O₂, 15% CO₂, and 82% N₂ was identified as the most effective, extending postharvest shelf life to 54 days. Additionally, a kinetic shelf-life prediction model based on firmness changes was developed with relative errors below 10%, demonstrating high accuracy. This study establishes an integrated preservation strategy combining subzero temperature (−1 °C) and optimized MAP (3% O₂, 15% CO₂, 82% N₂) that significantly extends the shelf life of Kyoho grapes, providing a practical solution for enhancing postharvest quality. Full article

Accurate and non-destructive evaluation of grape quality is crucial for intelligent viticulture, yet most existing approaches address cultivar classification and soluble solid content (SSC) prediction as independent tasks based on single-modality data, limiting robustness and practical applicability. This study proposes DualStream-RTNet, a unified multimodal deep learning framework that simultaneously performs grape cultivar classification and SSC prediction by integrating RGB-HSV fused images and PCA-compressed hyperspectral spectra. The dual-stream architecture enables the complementary learning of external chromatic–textural cues and internal physicochemical information, while a Transformer-enhanced fusion module strengthens global representation and cross-modal correlation. A dataset of 864 berries from five grape cultivars was used to validate the model. DualStream-RTNet achieved 93.64% classification accuracy, outperforming ResNet18 and other CNN baselines, and produced more compact and consistent confusion-matrix patterns. For SSC prediction, it consistently yielded the highest performance across cultivars, with R2p values up to 0.9693 and RMSE as low as 0.2567, surpassing the PLSR, SVR, LSTM, and Transformer regression models. These results demonstrate the superiority of the proposed framework in capturing both visual and spectral characteristics. DualStream-RTNet provides an efficient and scalable solution for comprehensive grape quality assessment, offering strong potential for real-time sorting, precision grading, and smart agricultural applications. Full article

This study evaluates viticultural parameters of the Golia grape variety in relation to variable climatic conditions over the 2020–2024 period and analyzes their impact on wine quality. The data show significant climatic variability, with warming trends causing earlier flowering and ripening by 11–13 days. Grape production varied depending on climatic conditions, with 2021 and 2024 recording the highest number of shoots per trunk and increased fertility in 2024. Low winter temperature led to reduced bud viability and affected the overall health of the vines and harvest yields. Average annual precipitation, especially from the growing season, significantly influenced actual yield (AY), while higher annual temperatures and sunshine duration (Sun) resulted in lower grape weight. Greater sugar concentrations accumulated in years with higher temperatures, while higher acidity levels registered at lower temperatures. Higher precipitation (Pp) coupled with thermal accumulation promoted higher dry extract and alcoholic strength (AS), significantly enhancing the perception of honey notes (R² > 0.7, p-value < 0.05). Furthermore, higher thermal regimes negatively impacted the expression of delicate aromatic compounds, diminishing specific notes such as rose and exotic fruits. Full article

Superconducting-qubit control is fundamentally constrained by decoherence, finite bandwidth, and hardware-limited drive amplitudes, making high-fidelity state preparation sensitive to optimizer initialization under non-convex open-system dynamics. We propose a hybrid reinforcement learning (RL)–quantum optimal control (QOC) pipeline in which a lightweight, tabular, model-free RL agent is trained offline in simulation to generate feasible, bounded seed pulses, which are subsequently refined via GRAPE under Lindblad dynamics. Hard amplitude constraints are enforced consistently across both stages, ensuring strict feasibility throughout optimization. Performance is evaluated using a budget-matched protocol based on fidelity evaluations (F-evals), enabling controlled comparison with random-start multi-start GRAPE. On a transmon-like qubit benchmark with relaxation and dephasing, RL warm-starting reduces the median online refinement effort in the adopted finite-difference GRAPE implementation from 7568 to 3543 F-evals (2.14× reduction) while achieving terminal state fidelity ≥0.995 under identical constraints and evaluation budgets. We provide a theoretical interpretation of the improvement in terms of basin-of-attraction probability shaping in constrained control landscapes and an amortized cost analysis showing that the offline RL cost is recovered after a small number of reuse cycles. The results support the view that learning-based initialization can improve warm-start quality relative to uninformed feasible multi-start in constrained open-system quantum-control benchmarks, while broader practical comparison against stronger physics-guided seeds remains for future work. Full article

The authentication of wines with Protected Designation of Origin (PDO) status is a key requirement for quality assurance, traceability, and consumer trust, particularly in traditional wine-producing regions such as the Douro Demarcated Region (Portugal). Among the certification criteria, the reliable identification of grape varieties remains technically challenging, especially when rapid and non-destructive analytical approaches are required. In this study, Fourier-transform infrared spectroscopy coupled with chemometric analysis was evaluated as a rapid screening approach for the differentiation of monovarietal Douro wines produced under standardized microvinification conditions. Twenty-one monovarietal wines were analyzed using mid-infrared spectra (1800–1000 cm⁻¹) and classification models were developed using Partial Least Squares Discriminant Analysis (PLS-DA). The PLS-DA models showed preliminary discriminatory capacity, with apparent error rates of 10.2% for calibration and 19.3% under leave-one-out cross-validation. The results indicate that FTIR-ATR spectroscopy combined with chemometrics captures chemically relevant spectral variability associated with grape varietal differences and shows potential as a rapid exploratory screening approach within PDO traceability frameworks. Although the study is based on a limited number of biological replicates from a single vintage and sub-region, the findings provide a methodological baseline for future multi-vintage and multi-region investigations aimed at consolidating FTIR-based approaches for varietal authentication of Douro wines. Full article

The fining of red wines is a crucial process for enhancing their sensory quality, involving the elimination of compounds that compromise stability or generate undesirable attributes. Against the backdrop of growing interest in sustainable and allergen-free alternatives, this study examines the potential of using cell wall material from white grape pomace (Zalema, Pedro Ximénez and Moscatel varieties) as fining agents in red wine. Cell wall samples were isolated and characterised using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). PCA applied to the cell wall spectra revealed homogeneous matrices dominated by structural polysaccharides, including cellulose, hemicellulose, lignin, pectins and arabinogalactans. Following the fining treatments, significant differences were observed in the generated sediments compared to the control, primarily due to signals attributable to phenols, proteins, and carbohydrates. This demonstrates the active involvement of these compounds in the formation of precipitates. The results confirm that the composition of the cell wall favours interaction with phenols and proteins in wine, thereby contributing to their elimination. Overall, this work demonstrates the potential of cell wall material from white grape pomace as plant-based oenological fining agents, providing new insights into the molecular mechanisms of action. Full article

This study investigated the impact of including 10% of dried brewers’ grain (BG), grape pomace (GP), or olive cake (OC) in the finishing diets of thirty-two Ovella Galega lambs on their growth parameters and carcass quality. Productive parameters such as live weight, average daily gain (ADG), and subcutaneous fat depots were monitored. The following carcass traits were also evaluated: carcass weight, conformation, fatness degree, morphology, and pH. Moreover, the left-half carcasses were sectioned into the main commercial cuts. Results showed that the type of diet did not significantly affect (p > 0.05) the growth performance and carcass characteristic of the animals. All groups reported similar (p > 0.05) live weights, ADG, and pre-slaughter fat thickness. In the same manner, the lack of significant variations observed in the productive parameters was also reflected in the carcass traits, showing comparable (p > 0.05) weights, dressing percentages, conformation, fatness levels, morphometric measures, and pH among treatments. Furthermore, the commercial value of the animals was not compromised (p > 0.05) by the experimental treatments. Thus, these outcomes suggest that the employment of these agri-food by-products, at moderate levels, could represent a viable and sustainable feeding approach for these autochthonous lambs. Full article

Interannual variability in climatic conditions represents a major source of uncertainty in cool-climate viticulture, highlighting the need for cultivar-specific assessments of climate–quality relationships. A multi-year on-farm experiment with six monitoring sites has been conducted in vineyards representative of the Tokaj wine region to monitor and assess vintage effect. This study, as the first part of a broader research project evaluating must components, quantifies relationships between climatic indices and key yield- and sugar-related traits (berry weight, total soluble solids, and total dry extract) in Vitis vinifera L. cv. Furmint grown in the Tokaj wine region over three contrasting vintages. Thermal, radiative, and water-availability variables were calculated for discrete phenological phases and statistically analyzed to identify climatic predictors of berry growth and must composition. Berry weight exhibited pronounced vintage sensitivity, showing consistent associations with precipitation-related variables during early developmental stages. In contrast, total soluble solids and total dry extract displayed weaker and less consistent responses to interannual climatic variability. Several widely used heat-accumulation indices showed limited explanatory power, indicating a moderate climatic sensitivity of sugar-related traits in this cultivar. Overall, the results suggest that early-season climatic conditions exert a stronger influence on berry growth than late-season thermal extremes, while compositional parameters related to sugar accumulation remain comparatively stable. These findings highlight the need to incorporate cultivar-specific response functions into statistical models that assess projected climate-change effects on grape quality. Full article

In the context of global climate change, exploring locally adapted grape varieties has become imperative for the future of the wine industry. Autochthonous red grape varieties from Castilla y León region (Spain) are being studied as a sustainable option due to their local adaptation. This study aimed to evaluate different agronomic variables of nine minority varieties over four years at each vineyard, and their enological potential in two later vintages. Enological parameters and phenolic composition were analyzed in grapes and in the resulting wines to assess quality and typicity. Most of the grape varieties were able the produced good quality wines with distinct enological profiles. Bruñal, Cenicienta and Tinto Jeromo had characteristics associated with more structured wines (>1500 mg/L of total polyphenols and total tannins), making them suitable for oak aging. Estaladiña showed similar features, together with a very high productivity. Mouraz and Negro Saurí showed characteristics suitable for rosé wine production. Gajo Arroba and Mandón exhibited high total acidity (>4 g/L of tartaric acid), indicating their potential use in coupage to improve wine acidity. Overall, these varieties represent a valuable resource to increase wine diversity and resilience under changing climates. Full article

Climate change is intensifying summer stress conditions, with significant impacts on vine physiology and grape production. Kaolin is commonly used to mitigate heat stress, though its effectiveness may vary depending on vineyard conditions. This study aimed to compare the effects of kaolin application (K) with an untreated control (C) on Verdicchio grapevines across two distinct vineyard sites differing in environmental conditions over two consecutive growing seasons, focusing on leaf gas exchange, leaf temperature, grape composition and yield, and wine characteristics. Results showed that the effects of kaolin varied between sites. Under high thermal stress and low vine vigor, kaolin application improved gas exchange, sustained higher photosynthetic rates, and reduced leaf temperature. Conversely, in higher-vigor vineyards, the effects were less pronounced and mainly limited to reductions in leaf temperature. Under low-vigor conditions, K resulted in higher berry weight and lower total soluble solids. Wines from kaolin-treated grapes exhibited slightly reduced alcohol content and pH. These findings suggest that kaolin’s effectiveness is strongly influenced by climatic conditions and vine vigor. In Mediterranean regions, where heatwaves and drought are common, kaolin application may be a promising tool to alleviate heat stress, supporting improved grape yield and composition. Full article

Inter-row mulching with reflective film (RF) has been increasingly adopted in cool-climate vineyards to improve light availability and promote grape ripening. This study investigated the effects of ground-reflected light on the flavoromic profiles of wine grape berries (Vitis vinifera L.) over two consecutive vintages (2020–2021) in the Beijing Fangshan region of Eastern China, an area characterized by high precipitation and limited sunlight during ripening. Physicochemical analyses showed that RF treatment significantly increased total soluble solids (TSSs) and decreased titratable acidity (TA) at harvest. Targeted metabolomic analyses using HPLC–MS and GC–MS identified 21 flavonoids and 35 volatile compounds responsive to altered light conditions. RF treatment markedly enhanced the accumulation of anthocyanins and flavonols, especially malvidin-based derivatives, and increased terpene and norisoprenoid concentrations, while C₆/C₉ compounds were more abundant in control berries. Multivariate analysis revealed that PC1 was mainly associated with anthocyanin accumulation, clearly separating RF-treated samples, whereas PC2 reflected differences in flavonols and flavan-3-ols, with higher flavonols under RF and higher skin- and seed-derived flavan-3-ols in controls. Overall, these findings demonstrate that ground-reflected light plays a critical role in modulating grape flavor composition and provides practical guidance for improving fruit quality in suboptimal climatic regions. Full article

Hanseniaspora uvarum, formerly known as Kloeckera apiculata, is the predominant yeast species in grape musts for most wine fermentations worldwide. Despite its important impact on wine quality, its genetics has only been studied in some detail within the past decade, and methods for targeted manipulations first emerged in 2021. Since then, they have been improved and extended not only with respect to the wide applications of H. uvarum in beverage industries and as an environmental control agent, but also as tools in basic genetic research. In this review, the latest developments and future perspectives are summarized. Full article

Metschnikowia pulcherrima is increasingly valued in sustainable vitiviniculture for its dual role as a biocontrol agent and as a contributor to wine quality. However, a coordinated dual-purpose selection strategy has not yet been systematically implemented for this species. This study aimed to identify native strains with combined wine-related traits and biocontrol potential by screening a collection of 179 isolates for key phenotypic traits—β-glucosidase and β-lyase activities, hydrogen sulfide (H₂S) production, and pulcherrimin biosynthesis—and assessing their genotypic diversity. Dereplication yielded 106 unique strains, from which five with the most favorable wine-related traits and distinct genotypic profiles were selected for subsequent evaluation of antagonistic potential. Safety-related traits, including growth at 37 °C, invasive growth, pseudohyphal formation, and proteolytic activity, were assessed to exclude virulence-associated behaviors. Antagonistic activity against Botrytis cinerea was evaluated through in vitro dual-culture assays and in vivo grape-berry inoculations, revealing strain- and pathogen-dependent inhibition, with volatile-mediated effects generally exceeding direct-contact interactions. Among the tested strains, NLSFS4 showed strong and consistent biocontrol potential. Microvinification trials further confirmed its oenological relevance, demonstrating the ability to modulate wine aroma composition while preserving fermentation performance. Overall, this study highlights the substantial functional diversity within M. pulcherrima and identifies a promising native strain for integrated use in wine fermentation and biological control in sustainable production systems. Full article