Search Results (113)

Grapevine water relations are increasingly influenced by drought under climate change, with significant implications for yield, fruit composition and wine quality. Stable isotopes of hydrogen, oxygen, carbon and nitrogen (δ²H, δ¹⁸O, δ¹³C and δ¹⁵N) provide sensitive tracers of plant water sources and physiological responses to stress. Here, we combined dual water isotopes (δ²H, δ¹⁸O), carbon and nitrogen isotopes (δ¹³C, δ¹⁵N), and high-resolution micrometeorological/soil observations to diagnose drought dynamics in Vitis vinifera cv. Sauvignon blanc (Orlești, Romania; 2023–2024). Dual-isotope relationships delineated progressive evaporative enrichment along the soil–plant–atmosphere continuum, with slopes LMWL ≈ 6.41 > stem ≈ 5.0 > leaf ≈ 2.2, consistent with kinetic fractionation during transpiration (leaf) superimposed on source-water signals (stem). Weekly leaf δ¹⁸O covaried strongly with relative humidity (RH; r = −0.69) and evapotranspiration (ET; r = +0.56), confirming atmospheric control of short-term enrichment, while stem isotopes showed buffered responses to soil water. We integrated Δ¹⁸O (leaf–stem), RH, ET, and soil matric potential at 60 cm (Soil₆₀) into an Isotopic Drought Index (IDI), which captured the onset, intensity, and persistence of the July–August 2024 drought (IDI_0–100 > 90; RH < 60%, ET > 40 mm wk⁻¹, Soil₆₀ > 100 cb). Carbon and nitrogen isotopes provided complementary, integrative diagnostics: δ¹³C increased (less negative) with drought (r = −0.52 with RH; +0.49 with IDI), reflecting higher intrinsic water-use efficiency, whereas δ¹⁵N rose with soil dryness and IDI (leaf: r ≈ +0.48 with Soil₆₀; +0.42 with IDI), indicating constraints on N acquisition and enhanced internal remobilization. Together, multi-isotope and environmental data yield a mechanistic, field-validated framework linking atmospheric demand and edaphic limitation to vine physiological and biogeochemical responses and demonstrate the operational value of an isotope-informed drought index for precision viticulture. Full article

Wine samples (72) of different types (white, rose and red), dry, originating from different regions of Greece (Northern Greece, Central Greece, Peloponnese, Aegean Islands, and Crete), were analyzed for Ochratoxin A (OTA) presence. Wine samples, originating from Greek (Assyrtiko and Xinomavro) and international (Syrah and Sauvignon blanc) noble grapevine varieties vintaged from 2020 to 2023, were analyzed using a modified QuEChERS extraction protocol followed by HPLC with a fluorescence detector to detect and quantify OTA. Moreover, conventional oenological parameters were measured according to OIV official methods, and climatic conditions of the regions of concern were retrieved. Interestingly, in general, OTA contaminated wines showed low concentrations (<2.0 μg/L). The highest concentrations of OTA were detected in Sauvignon blanc (7.5 μg/L) regarding the white wines and Xinomavro (2.07 μg/L) regarding the red ones. In addition, the highest OTA concentrations were recorded in wines produced in areas either with high mean annual temperatures, like Viotia (24.16 °C) for white and Larissa (23.9 °C) for red wines, or with high rainfall between May and September (Larissa 69.76 mm) for white wines. Consequently, it was observed that concentrations of OTA in wine are relatively higher in the warmer regions of Greece compared to the cooler areas. The effect of climate change on vines and mycotoxin presence in wine needs urgent consideration by well-constructed modelling studies and efficient interpretation of existing data. The evaluation of OTA presence in grape products originating from various cultivars and regions is imperative not only for providing crucial data to predict its fate under climate change, but also to ascertain the potential risk of human exposure to this chemical compound. Full article

The evolution of the winemaking industry towards intelligent and digitalized systems is crucial for precision winemaking and ensuring product safety. In this context, the Internet of Things (IoT) provides a key strategy for real-time monitoring and data management throughout the winemaking process. However, comprehensive multi-parameter IoT-based monitoring and time-series prediction of physicochemical parameters during storage are currently lacking, limiting the ability to assess storage conditions and provide early warning of quality deterioration. To address these gaps, a multi-parameter IoT monitoring system was designed and developed to track conductivity, dissolved oxygen, and temperature in real time. Data were transmitted via a 4th-generation (4G) mobile communication module to the TLINK cloud platform for storage and visualization. An 80-day storage experiment confirmed the system’s reliability for long-term monitoring, and analysis of parameter trends demonstrated its effectiveness in assessing storage conditions and wine quality evolution. Furthermore, Long Short-Term Memory (LSTM), Gated Recurrent Unit (GRU), Temporal Convolutional Network (TCN) models, and Autoregressive Integrated Moving Average (ARIMA) were implemented to predict physicochemical parameter trends. The TCN model achieved the highest predictive performance, with coefficients of determination (R²) of 0.955, 0.968, and 0.971 for conductivity, dissolved oxygen, and temperature, respectively, while LSTM and GRU showed comparable results. These results demonstrate that integrating IoT-based multi-parameter monitoring with deep learning time-series prediction enables real-time detection of abnormal storage and quality deterioration, providing a novel and practical framework for early warning throughout the wine storage process. Full article

The identification of melatonin in grapes has led to the publication of numerous studies on melatonin in wines, and the aim of this study was to perform a systematic review and meta-analysis of published data on melatonin concentrations in wines. In this context, international databases such as Scopus, Web of Science and PubMed were searched for relevant articles (437) up to 29 March 2025. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. A total of 15 studies from eight countries, involving various wine types and analytical methods, were included in the meta-analysis. Considerable analytical variation was observed across studies, and high-performance liquid chromatography (HPLC) coupled with either mass spectrometry (MS) or fluorescence (FL) detection was shown to be the most accurate and sensitive method for quantifying melatonin. The highest concentrations were found in Spanish red Tempranillo wine, Romanian white Noah wine, and Romanian rosé Lidia wine. Red wines, particularly those produced from Cabernet Sauvignon (CS) grapes, were the most frequently studied. The results of this work provide a clearer picture of melatonin levels in wine. Further research is needed to explore the implications of melatonin content in wine for human health and the wine industry. Full article

High-acidity fruit wines, such as sea buckthorn wine, are valued for their nutritional benefits but often suffer from excessive tartness and limited aroma complexity, which restrict their consumer acceptance. The application of non-Saccharomyces yeasts with acid tolerance and flavor-enhancing potential offers a promising strategy to address these challenges. In this study, a highly acid-tolerant yeast strain, Pichia kudriavzevii GAAS-JG-1, was isolated from a naturally fermented apricot system and systematically characterized in terms of its taxonomy, physiological properties, and fermentation potential. The experimental results demonstrated that Pichia kudriavzevii GAAS-JG-1 maintained robust growth activity (OD₆₀₀ = 1.18 ± 0.09) even under extremely acidic conditions (pH 2.0). Furthermore, the strain exhibited a strong tolerance to high ethanol concentrations (16%), elevated sugar levels (350 g/L), and substantial sulfur dioxide exposure (500 mg/L). Optimal growth was observed at 35 °C (OD₆₀₀ = 2.21 ± 0.02). When co-fermented with Saccharomyces cerevisiae in sea buckthorn wine, the ethyl acetate content increased significantly from 303.71 μg/L to 4453.12 μg/L, while the ethyl propionate levels rose from 5.18 μg/L to 87.75 μg/L. Notably, Pichia kudriavzevii GAAS-JG-1 also produced novel flavor compounds such as methyl acetate and ethyl 3-methylthiopropionate, which were absent in the single-strain fermentation. These findings highlight the potential of Pichia kudriavzevii GAAS-JG-1 as a valuable non-Saccharomyces yeast resource with promising applications in the fermentation of high-acidity specialty fruit wines. Full article

Climate fluctuations due to global warming significantly impact the wine grape industry. This study introduces the Standardized Temperature Adaptation Index (STAI), which is specifically designed to isolate temperature trends and quantify the effects of temperature fluctuations on low-temperature stress affecting Cabernet Sauvignon branches and yields in the wine grape production regions of Xinjiang. A low-temperature fluctuation experiment was conducted on Cabernet Sauvignon branches to simulate the temperature conditions and fluctuations experienced by wine grapes during the overwintering period. The treated branches then underwent recovery growth experiments, during which key physiological stress parameters were measured to assess the impact of temperature fluctuations on grape growth and development during overwintering. The results indicated that under identical low-temperature conditions, increased temperature fluctuations led to a 62% reduction in the budding rate of Cabernet Sauvignon branches, a 6% increase in relative conductivity, and elevated levels of proline, malondialdehyde, and soluble proteins. Additionally, the activities of superoxide dismutase, peroxidase, and catalase initially rose and then declined, indicating that temperature fluctuations intensified low-temperature stress. Data analysis from four wine grape production regions in Xinjiang between 2000 and 2020 revealed that temperature fluctuations corresponded with the peaks and troughs of yield fitting curves, demonstrating a negative correlation. As temperature fluctuations increased, yields decreased. The STAI introduced in this study is a straightforward, standardized measure that accurately reflects the effects of temperature fluctuations on grapes and is a valuable tool for future research on temperature variability and its impacts. Full article

A lack of distinctive features has become a significant factor limiting the development of kiwi wine. However, the rapidly growing trend of healthcare-oriented composite fruit wine with health functions and diverse flavors presents a way to address this issue. A kiwi wine fermentation method was investigated by incorporating the medicinal and edible fruits of Cornus officinalis. The results indicate that adding Cornus officinalis introduced a unique component known as iridoid glycosides to the wine. Additionally, the concentrations of phenols, total iridoid glycosides, and most aroma compounds in the wine increased after the addition of crushed Cornus officinalis following alcoholic fermentation. As the proportion of Cornus officinalis in the kiwi wine rose, so did polyphenolic substances and total iridoid glycosides; however, this diminished the wine’s clarity. Additionally, a yeast addition of 200 mg/L demonstrated optimal fermentation capabilities, and a bentonite addition of 1.1 g/L exhibited an outstanding clarifying effect. These results not only enhance nutritional value and quality but also provide a theoretical foundation for the production of high-quality Cornus–kiwifruit composite wine. Full article

‘King of the North’ (‘KON’), as a cold-hardy grape, has many advantages, such as tolerance to a wide range of soil conditions and harsh winter climate. Due to the adapting demand of North Dakota’s fruit and wine industry, optimized quality of wine from regionally productive grapevines is required. In this study, yeast strain, one of the primary fermentation tactics, was tested on ‘KON’ grapes. Five different commercial yeast strains, including 71B, EC1118, Maurivin B, Rhône 4600, and W15, were added to initiate fermentation. The analysis of grape must characteristics and the fermentation dynamic changes indicated a high correlation between color and acid metrics. Yeast strains have influenced the color dynamic changes and fermentation process. The panelist sensory evaluations confirmed that yeast strains contributed differently to the perceived aromas and flavors within ‘KON’ wines. Rose, apple, grape, and apricot aromas were distinguished in ‘KON’ wines. The lemon taste was the dominant flavor detected in ‘KON’ wines. However, wines were also varied based on the extent of the aroma or taste observed. Therefore, exploring the use of different yeast strains for fermentation provides information for further application to cold-hardy grape cultivars and other high-acid fruit, aiding winemakers in using North American grapes with diverse fruit chemistry. Full article

Winemakers are increasingly adopting partial or total dealcoholisation of wines and alcoholic beverages in response to market trends and the impact of climate change on wine alcohol content. In this study, the patented very low-temperature vacuum wine distillation technology known as GoLo was used to dealcoholise various types of red, white, and rosé wines from different Spanish designations of origin (DOs) in order to examine changes in oenological parameters as pH, sulphites, total acidity, volatile acidity, and sugars and the perceptible differences among a set of wines through sensory analysis and the chemical analysis related, such as turbidity, total phenolic content, and a profile of volatile compounds. The results indicate that there is an increase in the overall polyphenol content in the range of 8 to 12%, turbidity increased in the range of 13 to 70%, and sulphites decreasing in the range of 20 to 40%. The aroma profile also reveals that the most volatile and less soluble compounds—such as esters (reduction between 60% and 96%), terpenes (reduction between 45% and 80%), and aldehydes (reduction between 86% and 95%)—are lost in varying percentages during the dealcoholisation process, depending on the type of wine. Meanwhile, other more soluble compounds like phenols and acids undergo transformations during GoLo’s dealcoholisation process, leading to an increase in their concentrations up to more than 90% in the case of phenols in white wines or 35% for acids in red wines. Full article

Marselan wine is characterized by distinctive flavors of blackcurrant, cranberry, and spice, which are significantly influenced by environmental factors such as region and climate. In this study, we analyzed the dynamic changes in the microbial community, physicochemical indices, and flavor compounds during the spontaneous fermentation of Marselan wine in Xinjiang using high-throughput sequencing (HTS), high-performance liquid chromatography (HPLC), and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS). The results indicated that the sugar content decreased from 259.12 g/L to 22.45 g/L, while the ethanol content increased to 13.63 ± 0.15% vol after 12 days of fermentation. The predominant aromatic components identified in Marselan grapes include isophorone, 2,3-pentanedione, 2-hexenal, and melonal. After fermentation, ethanol, phenethyl alcohol, isoamyl acetate, ethyl acetate, and ethyl hexanoate were produced, imparting rose, cream, and fruit flavors to wine. The key microorganisms involved in the spontaneous fermentation of Marselan wine include Saccharomyces, Starmerella, Pichia, Pseudomonas, Sphingomonas, and Aspergillus. These microorganisms contributed substantially to the main physicochemical indices and flavor profiles. Saccharomyces and Pichia enhanced the formation of most alcohols and esters, whereas Aspergillus, Acremonium, and Fusarium inhibited the synthesis of numerous volatile compounds. These findings provide valuable theoretical references for improving the quality of Marselan wines in Xinjiang. Full article

Greek wines made from the indigenous grape varieties Assyrtiko, Malagousia, Moschofilero and Roditis are attracting the interest of wine producers and consumers due to their aromatic characteristics. However, there are few studies that focus on the unique wine characteristics of each variety and the relationship between the composition of volatile compounds and sensory properties. Monovarietal white wines (2018 vintage) were analyzed by gas chromatography–mass spectrometry to quantify 34 volatile compounds. Multivariate statistical analyses were used to investigate correlations between volatiles and sensory attributes identified by a trained panel. The results showed that the strongest aroma compounds were a group of terpenes, isoamyl acetate and phenylethyl acetate. Terpenes such as geraniol, α-terpineol, linalool and cis-rose oxide correlated with floral notes, especially in Moschofilero wines. In addition, isoamyl acetate contributed to the aroma of tropical fruits, especially banana, in the Roditis wines, while phenylethyl acetate correlated with rose, vanilla and fruity notes in both the Moschofilero and Roditis samples. The Assyrtiko wines and the Malagousia wines were mainly associated with compounds such as cis-3-hexen-1-ol and cis- and trans-furan linalool oxides, which may enhance fresh fruit and citrus aromas through synergistic effects. The common background aroma of the studied wines was mainly determined by higher alcohols, fatty acids and ethyl esters. This study provides a basis for understanding the typical aroma of white wines from indigenous Greek grape varieties, which will help producers develop targeted wine styles and will be useful for consumer promotion. Full article

Exposure to short-wavelength light, including UV-A and blue light, can degrade high-value products like rosé wine, which are usually packaged in colourless bottles. This study investigates the optimisation of sol–gel coatings enhanced with UV-absorbing additives (Tinuvin 479 and semaSORB 20109) to provide photoprotection for rosé wines. Coatings with varying additive concentrations (0.5%, 0.75%, 1%, and 1.5%) were applied to glass substrates via spin coating and cured with UV light. Then, optical and mechanical characterisation was performed. The 1.5% concentration semaSORB 20109 bilayer coating demonstrated improved photoprotective properties without compromising colour properties, leading to successful application on glass bottles by spray coating. Accelerated degradation tests confirmed that the optimised coating effectively protected against photodegradation, as indicated by the stability of polyphenol levels and colour parameters in rosé wines. The results suggest that these coatings could be a suitable option for commercial-scale applications, enhancing the light resistance of colourless-bottled products. Full article

This study investigates the incorporation of pomegranate juice into the fermentation process to produce a novel rosé sparkling wine with enhanced antioxidant properties and improved acidity while preserving desirable sensory qualities. Initial trials blended a Glera base wine with 5%, 10%, and 15% pomegranate juice, followed by bottle fermentation to select the optimal formulation. The 10% blend, identified as the best, underwent a second fermentation in an autoclave using the Martinotti method. Chemical analyses were conducted to assess polyphenol content, protein stability, antioxidant activity, and colour, while sensory evaluations determined the flavour balance and acceptability. Results demonstrated that pomegranate juice significantly increased polyphenol content and antioxidant capacity. The 10% blend achieved balanced acidity, sweetness, and carbonation, with pronounced fruity and floral aromas. However, protein stability tests revealed haze formation, emphasizing the need for stabilization refinements. This study highlights the feasibility of integrating pomegranate juice into sparkling wine production. It explores alternative and innovative uses for pomegranate to maximize its potential beyond traditional applications, leverages its unique properties, such as high antioxidant content, to enhance value-added products, and demonstrates its potential to diversify the portfolio of fruit wines while appealing to modern consumer preferences. Full article

Free pectinase is commonly employed as a biocatalyst in wine clarification; however, its removal, recovery, and reuse are not feasible. To address these limitations, this study focuses on the immobilization of a commercial pectinolytic preparation (Pec) onto highly porous polymer microparticles (MPs). Seven microparticulate polyamide (PA) supports, namely PA4, PA6, PA12 (with and without magnetic properties), and the copolymeric PA612 MP, were synthesized through activated anionic ring-opening polymerization of various lactams. Pectinase was non-covalently immobilized on these supports by adsorption, forming Pec@PA conjugates. Comparative activity and kinetic studies revealed that the Pec@PA12 conjugate exhibited more than twice the catalytic efficiency of the free enzyme, followed by Pec@PA6-Fe and Pec@PA4-Fe. All Pec@PA complexes were tested in the clarification of industrial rosé must, demonstrating similar or better performance compared to the free enzyme. Some immobilized biocatalysts supported up to seven consecutive reuse cycles, maintaining up to 50% of their initial activity and achieving complete clarification within 3–30 h across three consecutive cycles of application. These findings highlight the potential for industrial applications of noncovalently immobilized pectinase on various polyamide microparticles, with possibilities for customization of the conjugates’ properties. Full article

The increasing demand for non-alcoholic beverages has led to the development of dealcoholized wines. However, current dealcoholization techniques often negatively impact wine aroma due to the loss of volatile compounds. This study investigates the impact of incorporating an aromatic distillate, collected during the spinning cone column (SCC) dealcoholization process, back into dealcoholized Tempranillo rosé wines. The aromatic distillate was added to dealcoholized wine in varying concentrations (0.5%, 1.0%, and 1.5% v/v). A total of 57 volatile compounds, including 25 varietal and 32 fermentative compounds, were identified and quantified using gas chromatography–mass spectrometry (GC-MS). The addition of the aromatic distillate significantly increased the concentration of several volatile compounds, notably C₆ compounds, terpenes, benzene compounds, and esters. The odor activity values (OAVs) reveal that increasing distillate concentrations led to a higher number of compounds with OAVs greater than 1, indicating enhanced individual aroma contributions. The fruity and sweet aromatic series were predominant in all samples, with their total intensity increasing with higher distillate concentrations. However, the addition of 1.5% v/v of the aromatic distillate (AW3) resulted in an alcohol content exceeding the legal limit for dealcoholized wine, classifying it as a reduced-alcohol wine. The study concludes that adding 1% v/v of the aromatic distillate to dealcoholized Tempranillo rosé wine effectively enhances the aroma profile while remaining within regulatory limits for dealcoholized wine. This approach presents a viable method for producing high-quality, aromatic, dealcoholized wines that meet consumer demand for non-alcoholic beverages. Full article