Wine Quality Research Articles

Impact of phenylalanine on Hanseniaspora vineae aroma metabolism during wine fermentation

Hanseniaspora vineae exhibits extraordinary positive oenological characteristics contributing to the aroma and texture of wines, especially by its ability to produce great concentrations of benzenoid and phenylpropanoid compounds compared with conventional Saccharomyces yeasts. Consequently, in practice, sequential inoculation of H. vineae and Saccharomyces cerevisiae allows to improve the aromatic quality of wines. In this work, we evaluated the impact on wine aroma produced by increasing the concentration of phenylalanine, the main amino acid precursor of phenylpropanoids and benzenoids. Fermentations were carried out using a Chardonnay grape juice containing 150 mg N/L yeast assimilable nitrogen. Fermentations were performed adding 60 mg/L of phenylalanine without any supplementary addition to the juice. Musts were inoculated sequentially using three different H. vineae strains isolated from Uruguayan vineyards and, after 96 h, S. cerevisiae was inoculated to complete the process. At the end of the fermentation, wine aromas were analysed by both gas chromatography–mass spectrometry and sensory evaluation through a panel of experts. Aromas derived from aromatic amino acids were differentially produced depending on the treatments. Sensory analysis revealed more floral character and greater aromatic complexity when compared with control fermentations without phenylalanine added. Moreover, fermentations performed in synthetic must with pure H. vineae revealed that even tyrosine can be used in absence of phenylalanine, and phenylalanine is not used by this yeast for the synthesis of tyrosine derivatives.

Establishing the processing factor and degradation kinetics of hexaconazole residues in vinification and its residual impact on wine quality and aroma characteristics by GCxGC-ToF/MS analysis

Hexaconazole (HX), a triazole fungicide, is widely used for controlling mildews in commercial viticulture, and residues at harvest are a challenge. The pesticide residues in the harvested grapes may impact the grape and wine quality. In this study, we have investigated the fate of HX residues in the vinification with wine aroma and quality. HX was applied at the recommended dose (RD) and 10 times RD (10 RD). The HX residue dissipation exhibited first-order kinetics with a half-life of 3.5 and 2.5 days for RD and 10 RD, respectively. The processing factor from grape to wine ranged from 0.04 to 0.09, the transfer rate ranged from 2.46% to 6.47%. The HS-SPME-GCxGC-ToF/MS analysis revealed a significant impact on volatile organic compounds (VOCs). The concentration of key VOCs varied in control as esters (147.62 μg L−1), alcohols (144.81 μg L−1), acids (82.92 μg L−1) and in HX RD treated wines showed reduction in alcohols (111.32 μg L−1), esters (91.57 μg L−1) and acids (67.10 μg L−1). In 10 RD, alcohols, esters, acids were declined as 131.42 μg L−1, 118.65 μg L−1, and 75.73 μg L−1 respectively. In HX RD, 28 were up and 58 VOCs were down-regulated. 40 VOCs were up and 46 were down-regulated in HX 10 RD wine. The pathway enrichment analysis revealed impact of HX residues on glycolysis and pyruvate metabolism. Quality analysis showed variation in total flavonoids, phenols, and anthocyanin content. The results revealed that HX residues have a negative impact on wine aroma and metabolism during vinification.

Co-inoculation of Meyerozyma guilliermondii and Saccharomyces cerevisiae reduced alcohol content and improved flavor profiles of red pitaya (Hylocereus polyrhizus) wine

Abstract Red pitaya (Hylocereus polyrhizus) is cultivated in tropical and subtropical regions worldwide. Red pitaya is rich in nutritional and medicinal ingredients. Oenological yeasts play vital roles in wine fermentation by metabolizing a variety of aromatic compounds that affect the flavor and sensory properties of wine. In this study, we examined the influence of Meyerozyma guilliermondii on the physicochemical parameters, sensory properties, and aroma chemical composition of red pitaya wine co-inoculated with Saccharomyces cerevisiae. The results showed that mixed inoculation of M. guilliermondii and S. cerevisiae reduced the alcohol content of red pitaya wine. Moreover, using M. guilliermondii and S. cerevisiae as fermentation starters increased the content of volatile alcohols, aldehydes, ketones, and other compounds, as well as the types of alcohols, aldehydes, and ketones. In addition, M. guilliermondii did not affect the sensory characteristics of the red pitaya wine. Therefore, co-inoculation of M. guilliermondii and S. cerevisiae was helpful in enhancing the richness and complexity and improving the aromatic flavor properties of red pitaya wine. The results obtained in this study could serve as a reference for the production of red pitaya wine and other fruit wines.

Lachancea thermotolerans fermentative metabolism is enhanced by chitosan under winemaking conditions

Wine industry is currently exploring different alternatives to sulphur dioxide as an antimicrobial agent, and chitosan is emerging as a highly promising option due to its multiple applications. In the context of climate change, the use of Lachancea thermotolerans to regulate pH and acidity levels during fermentation has become a promising alternative to other physicochemical approaches. This work analysed the impact of chitosan in sequential-mixed fermentations between L. thermotolerans and Saccharomyces cerevisiae. The presence of chitosan significantly affected the overall fermentation kinetics, resulting in faster fermentations and lower residual sugars, all without an increase in ethanol production. Wines produced under these conditions exhibited increased lactic acid levels (up to 50% more) and decreased malic acid content. This differences significantly influenced final pH (around 0.2 units) and acidity content (up to 1.65 g/L more) when compared to sulphur dioxide-supplemented controls. Chitosan also notably affected to other fermentative by-products, such as glycerol, contributing to improved wine complexity and quality. The addition of chitosan in wine fermentation impacted not only the fermentative performance of key non-Saccharomyces yeasts but the overall quality of the final product. This study provides new insights into the different effects of chitosan during the wine fermentative process.

Emerging Roles of Epigenetics in Grapevine and Winegrowing.

Epigenetics refers to dynamic chemical modifications to the genome that can perpetuate gene activity without changes in the DNA sequence. Epigenetic mechanisms play important roles in growth and development. They may also drive plant adaptation to adverse environmental conditions by buffering environmental variation. Grapevine is an important perennial fruit crop cultivated worldwide, but mostly in temperate zones with hot and dry summers. The decrease in rainfall and the rise in temperature due to climate change, along with the expansion of pests and diseases, constitute serious threats to the sustainability of winegrowing. Ongoing research shows that epigenetic modifications are key regulators of important grapevine developmental processes, including berry growth and ripening. Variations in epigenetic modifications driven by genotype-environment interplay may also lead to novel phenotypes in response to environmental cues, a phenomenon called phenotypic plasticity. Here, we summarize the recent advances in the emerging field of grapevine epigenetics. We primarily highlight the impact of epigenetics to grapevine stress responses and acquisition of stress tolerance. We further discuss how epigenetics may affect winegrowing and also shape the quality of wine.

Pre-Fermentative Cryogenic Treatments: The Effect on Aroma Compounds and Sensory Properties of Sauvignon Blanc and Chenin Blanc Wine—A Review

Low-temperature treatments preceding alcoholic fermentation are becoming increasingly popular and have been used in winemaking as a tool to improve wine colour, aroma, and quality. Additionally, the pre-fermentative treatment of grapes with cryogenic agents protects the grape juice (must) from oxidation by reducing the diffusion of atmospheric oxygen into the liquid phase during the winemaking process. Resultant wines were reported to have enhanced varietal aromas, increased complexity, and higher thiol levels. Indications are that increased contact time between skin and juice improves the extraction of the compounds and/or precursors. Recently, there has been considerable interest in the production of wines with enhanced varietal aromas and improved quality by applying innovative winemaking technologies. This review aims to provide an overview of the aroma and organoleptic quality of Sauvignon blanc and Chenin blanc wines produced from grapes that were subjected to pre-fermentative cryogenic treatments including the impact aroma compounds, i.e., volatile thiols and methoxypyrazines.

The effect of probe density coverage on the detection of oenological tannins in Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) experiments.

Polyphenols are a group of compounds found in grapes, musts, and wines. Their levels are crucial for grape ripening, proper must fermentation, and final wine characteristics. Standard chemical analysis is commonly used to detect these compounds, but it is costly, time-consuming, and requires specialized laboratories and operators. To address this, this study explores a functionalized acoustic sensor for detecting oenological polyphenols. The method involves utilizing a Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) to detect the target analyte by using a gelatin-based probe layer. The sensor is functionalized by optimizing the probe coverage density to maximize its performance. This is achieved by using 12-mercaptododecanoic acid (12-MCA) to immobilize the probe onto the gold sensor surface, and dithiothreitol (DTT) as a reducing and competitive binding agent. The concentration of 12-MCA and DTT in the solutions is varied to control the probe density. QCM-D measurements demonstrates that the probe density can be effectively adjusted using this approach, ranging from 0.2×1013 molecules cm-2 to 2×1013 molecules cm-2 . This study also investigates the interaction between the probe and tannins, confirming the sensor ability to detect them. Interestingly, the lower probe coverage achieves higher detection signals when normalized to probe immobilization signals. Moreover, significant changes in mechanical properties of the functionalization layer are observed after the interaction with samples. The combination of QCM-D with gelatin functionalization holds great promise for future applications in the wine industry. It offers real-time monitoring capabilities, requires minimal sample preparation, and provides high sensitivity for quality control purposes. This article is protected by copyright. All rights reserved.

Feasibility assessment of a low-cost visible spectroscopy-based prototype for monitoring polyphenol extraction in fermenting musts.

Polyphenols have long been used to evaluate grape and wine quality and it is necessary to measure them throughout various winemaking stages. They are currently assessed predominantly through analytical methods, which are characterized by time-consuming procedures and environmentally harmful practices. Non-destructive spectroscopy-based devices offer an alternative but they tend to be costly and not readily accessible for smaller wineries. This study introduces the initial steps in employing a portable, user-friendly, and cost-effective visible (VIS) spectrophotometer prototype for direct polyphenol measurement during winemaking. Grapes (cv Syrah, Bobal, and Cabernet Sauvignon) at different maturation stages were fermented with or without stems. Throughout fermentation, parameters such as color intensity, total polyphenol index, total anthocyanins, and tannins were monitored. Concurrently, VIS spectra were acquired using both the prototype and a commercial instrument. Chemometric approaches were then applied to establish correlation models between spectra and destructive analyses. The prototype models demonstrated an acceptable level of confidence for only a few parameters, indicating their lack of complete reliability at this stage. Visible spectroscopy is already utilized for polyphenol analysis in winemaking but the aspiration to automate the process in wineries, particularly with low-cost devices, remains unrealized. This study investigates the feasibility of a low-cost and user-friendly spectrophotometer. The results indicate that, in the early stages of prototype utilization, the goal is attainable but requires further development and in-depth assessments. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

New insight in characterization of red wine astringency using soft tribology method

AbstractThe variation of friction coefficient (μ) of model wine and model saliva mixtures with entrainment speed (VR) on simulated oral surfaces was evaluated by oral tribology. Combined with techniques of dynamic light scattering (DLS), atomic force microscopy (AFM), rheometer, and quartz crystal microbalance with dissipation monitoring (QCM‐D), the correlation between characteristics of the model wine and model saliva mixtures (particle size and morphology, suspension viscosity, adsorption film thickness, and viscoelasticity) and the oral lubrication loss was established. The results showed that the higher the concentration of tannin in the model wine, the larger the size of the complexes with the model saliva, and the higher the thickness, viscoelasticity, and roughness of the adsorption film formed, which resulted in the increase of friction coefficient in the boundary lubrication regime. Different from previous results, it is found that the maximum value of the friction coefficient (μmax) in the boundary regime has the best positive correlation with the astringency perception intensity of the model wine accordingly.

Influence of soil management on vegetative growth, yield, and wine quality parameters in an organic “Pedro Ximénez” vineyard: field and UAV data

The use of cover crops in vineyards is expected to increase due to the strong encouragement by European agricultural policy and their contribution to reducing soil erosion. This paper presents the results obtained over three years in a vineyard of the “Pedro Ximénez” variety organically grown in southern Spain. The influence on production, vigor, and grape quality of a seeded cover crop versus tillage was compared using field data and imagery acquired by an uncrewed aerial vehicle. The vines under tillage showed greater vegetative development and yield than those with cover crops between rows. The grapes from the vines under the cover crop treatment ripened earlier and presented higher values of total soluble solids, characteristics that can be useful in the protected designation of origin where the study field is placed. However, the strong yield reduction caused by the cover crop treatment encourages future research to explore other cover crop species that could contribute to improving soil properties without compromising the profitability of the vineyard. This is the first time that the influence of cover cropping on the agronomic and oenological parameters of organically grown white vineyard varieties such as “Pedro Ximénez” has been assessed using field and UAV data.

The effectiveness of PCA and various hyperparameter settings in SVM and KNN for wine quality estimation

Wine is popular around the world and wine quality evaluation is focused by the wine companies. Wine quality prediction through machine learning is expected to mitigate the waste of time and money of artificial wine quality prediction. Previous researches focused on simple applications and comparisons of the machine learning methods on the wine dataset, but the exploration of optimal parameters of models lacked. Therefore, this research mainly aimed to determine wine quality based on known data by implementing various machine learning models and find the optimal model for predicting the wine quality. For the optimal model, the detailed value of parameter and setting are aimed to be explored. This paper trained five machine learning algorithms and tested them on a wine dataset. The impact of standardization on different machine learning models was tested. Except for decision tree and AdaBoost, standardization is an effective method to improve the performances of different methods. Support vector machine (SVM) with rbf kernel performed best among different SVM classifiers. K-nearest neighbor (KNN) of twenty-five neighborhood points combined with principal component analysis (PCA) of five principal components showed 90.94% accuracy and it is the optimal algorithm.

Forecasting red wine quality: A comparative examination of machine learning approaches

This research explores the forecast of red wine quality utilizing machine learning algorithms, with a particular emphasis on the impact of alcohol content, sulphates, total sulfur dioxide, and citric acid. The original dataset, comprised of Portuguese "Vinho Verde" red wine data from 2009, was bifurcated into binary classes to delineate low-quality (ratings 1-5) and high-quality (ratings 6-10) wines. A heatmap verified the potent correlation between the chosen variables and wine quality, paving the way for their inclusion in our analysis. Four machine learning techniques were employed: Logistic Regression, K-Nearest Neighbors (KNN), Decision Tree, and Naive Bayes. Each technique was trained and assessed through resulting metrics and graphical visualizations, with diverse proportions of data assigned for training and testing. Among these techniques, Logistic Regression achieved an accuracy score of 72.08%, while KNN slightly surpassed it with an accuracy rate of 74%. The Decision Tree technique rendered the peak accuracy of 74.7%, while Naive Bayes underperformed with a score of 60.2%. From a comparative viewpoint, the Decision Tree technique exhibited superior performance, positioning it as a viable instrument for future predictions of wine quality. The capacity to predict wine quality carries significant implications for wine production, marketing, customer satisfaction, and quality control. It enables the identification of factors contributing to high-quality wine, optimization of production processes, refinement of marketing strategies, enhancement of customer service, and potential early identification of substandard wines before reaching consumers, thereby safeguarding the brand reputation of wineries.

Geographical location influence ‘Cabernet Franc’ fruit quality in Shandong province

Grape quality is a key factor in determining wine quality, and it depends not only on management skills, but also on the geographic location of the producing area. In China, Shandong is the province with the largest wine production, and ‘Cabernet Franc’ is widely planted. This study evaluated the ‘Cabernet Franc’ fruit quality in relation to geographical conditions in five ‘Cabernet Franc’ producing districts of Shandong province, China, including Dezhou Aodeman Winery (DZ), Tai’an Zhongqingsongshi Winery (TA), Penglai Longhu Winery (PL), Rushan Taiyihu Winery (RS), and Rizhao Taiyangcheng Winery (RZ). At the time of veraison and maturity, fruit was harvested from five areas, and compared for cosmetic and internal fruit quality. The soluble sugar content in the Rizhao area was rich, and the weight and volume of single fruit were relatively large. The titratable acid of the berries in Tai'an area was high. RNA-seq analysis showed that the number of genes in the véraison stage was 19,571–20,750, and the number of genes in the mature stage was 19,176–20,735. The analysis found that areas with multiple high-quality characteristics tended to have more DEGs (differential expressed genes). And the DEGs in different areas were mainly distributed on chromosome 7, and at least on chromosome 15. DEGs in 5 areas were enriched on 855 GO terms and 116 KEGG pathways during berries development. Among them, it was found that the up/down-regulation of DEGs was related to the formation of berry quality, which helps to explain the impact of environment on grape quality components. In summary, this study is helpful to understand the influence of cultivation location on the quality of 'Cabernet Franc' in different production areas in Shandong province, and further provide a reference for the production of high-quality wine grapes and winemaking.

СОВРЕМЕННЫЕ ЗАДАЧИ НАУЧНЫХ ИССЛЕДОВАНИЙ В ОБЛАСТИ ВИНОДЕЛИЯ

The article presents the results of research activities for 2023 of the Federal State Budget Scientific Institution All-Russian National Research Institute of Viticulture and Winemaking Magarach of the RAS in the field of winemaking, carried out in accordance with the Program of Fundamental Scientific Research in the Russian Federation for the long term (2021-2030). The methodology of wine quality management with ecostatus has been created, aimed at revealing the individual characteristics of wines caused by natural factors and reducing the risks of negative effects on humans. Promising yeast strains have been identified: Steinberg, Champanskaya G-14, ShM-30, Novocimlyanskaya 3 with a description of their taxonomic affiliation, morphological and physiological-biochemical properties. Two strains of O. oeni active acid-reducing agents are recommended for practical use. The application of technology for the production of young sparkling wines of Crimean autochthonous grape The article presents the results of research activities for 2023 of the Federal State Budget Scientific Institution All-Russian National Research Institute of Viticulture and Winemaking Magarach of the RAS in the field of winemaking, carried out in accordance with the Program of Fundamental Scientific Research in the Russian Federation for the long term (2021-2030). The methodology of wine quality management with ecostatus has been created, aimed at revealing the individual characteristics of wines caused by natural factors and reducing the risks of negative effects on humans. Promising yeast strains have been identified: Steinberg, Champanskaya G-14, ShM-30, Novocimlyanskaya 3 with a description of their taxonomic affiliation, morphological and physiological-biochemical properties. Two strains of O. oeni active acid-reducing agents are recommended for practical use. The application of technology for the production of young sparkling wines of Crimean autochthonous grape varieties: Kokur belyi, Sary Pandas, Soldaiya and Kefesiya is justified. The system of criteria indicators for assessing the quality of grapes for the production of high-quality cognac distillates and cognacs is substantiated. A working collection of 63 natural strains of lactic acid bacteria has been formed. The optimal technological factors of the process of single-stage extraction by infusing with a food water-alcohol solution of green grape shoots of the Vitis vinifera, Vitis abrusca species have been established, allowing to increase the yield of total polyphenols by at least 2.6 times for the production of functional products. The most optimal technological modes of cold treatment of dry and fortified wine materials have been established to substantiate the constructive solution of an energy-saving installation for the purpose of cold treatment of wine materials based on the study of the main factors affecting the mass transfer process of potassium bitartrate crystallization. The obtained results of research work contribute to improving the quality of domestic wine products and expanding its production, including winemaking with ecological and geographical statuses, the production of domestic cognac and grape processing products of a functional orientation. The introduction of scientific developments into production will increase the competitiveness of domestic wine products, accelerate import substitution and ensure the country's food independence.

ОСНОВНЫЕ ИТОГИ НАУЧНЫХ ИССЛЕДОВАНИЙ ВСЕРОССИЙСКОГО НАУЧНО-ИССЛЕДОВАТЕЛЬСКОГО ИНСТИТУТАВИНОГРАДАРСТВА И ВИНОДЕЛИЯ ИМЕНИ Я.И. ПОТАПЕНКО – ФИЛИАЛА ФГБНУ «ФЕДЕРАЛЬНЫЙ РОСТОВСКИЙ АГРАРНЫЙ НАУЧНЫЙ ЦЕНТР» ЗА 2023 ГОД

The article presents the results of scientific research conducted by the ARRIV&W – branch of the FSBSI FRARC in 2023. As a result of the research, new knowledge was obtained in the field of viticulture and winemaking, data was obtained on the agrobiological potential of autochthonous and introduced varieties in the Don ampelographic collection named after Ya.I. Potapenko, systematization and digitalization of ampelographic resources data was carried out, 3 databases of grape ampelographic resources and the conditions of their growth were created. Varieties resistant to harmful organisms have been identified. Recommendations on the variety assortment and direction of use of autochthonous and introduced varieties have been developed. A method for storing grape plants in in vitro culture, methods for forming a collection and long-term non-transplant storage of grape plants in in vitro culture, ensuring non-transplant storage of microplants for up to 10-12 months have been developed. Breeding material was obtained: 25 sources of valuable traits (large size, productivity, resistance to mildew), 21 seedlings were selected as elite. Two grape varieties were submitted to the State Varietal Testing. An improved technology for obtaining basic planting material has been developed. The technology of adaptation to non-sterile conditions has been improved. Technologies for the production of planting material using PAS and elicitors have been developed. Seven modifications of high-standard grape formations have been developed, and optimal agro-technical parameters for cultivating grapes under various cultivation methods have been determined. Based on the analysis of geophysical, geological, climatic and soil characteristics, experimental data were obtained on the zoning of vineyard lands in the Rostov region, the determination of ecological, agrobiological, technological parameters that determine the terroirs of the Rostov region, the development of technologies that improve the quality wine products.

Douro Vineyards: A Perspective for the Valorization and Conservation of Grapevine Genetic Resources

The wine industry is one of the most important industries globally, particularly for Portugal, making a significant contribution to the Portuguese Bioeconomy. The Douro Demarcated Region (DDR) stands out as one of the largest wine-producing areas in the country. Its centuries-old culture has fostered a rich diversity, developed through vegetative and genetic breeding. Within the wine market, the highest prices for grapes are attained only under optimal edaphoclimatic conditions and when phenotypic characteristics, such as berry size and color, flowering and seed number, align favorably. Viticulture is influenced by environmental factors, diseases, and pests, impacting its economic value, profitability, and, ultimately, the employment and economic conditions of those dependent on the crops. Genetic improvement of phenotypic traits offers a faster and more cost-effective means of achieving desirable characteristics, translating into enhanced productivity and wine quality. This work focuses on presenting information about Douro grapes (region, varieties, diseases/pest, and economic value) and explores grapevine genetic diversity, along with approaches to identify genes associated with various desired traits.

Vine spacing of <i>Vitis vinifera</i> cv. Shiraz/101-14 Mgt. I. root growth and physiological activity

Knowledge of vine reaction to plant spacing under relatively high potential soil conditions is limited. This study comprised effects of vine spacing (with fixed row spacing) of Shiraz (clone SH 9C)/101-14 Mgt on a high potential soil in the Breede River Valley, Robertson, South Africa, on soil conditions, root system distribution, and vine physiological reaction. The vineyard was planted in 2008 to a VSP trellis, with a fixed row spacing of 2.2 m and a row orientation of approximately NNE–SSW (30°). In-row vine spacing changed from 0.3–4.5 m with increments of 30 cm (from 15151–1010 vines/ha), totalling 15 treatments. After the completion of cordon development, results were generated over six seasons. Soil conditions seemed generally uniform and showed no obvious characteristics that could have affected treatments differentially. An increase in density occurred in fine, extension and permanent root categories with closer spacing, increasing the total number of roots/ha. Roots penetrated deeper with closer vine spacing. Vine spacing impacted physiological parameters and revealed a complex interplay between root distribution, vine structure expansion, canopy microclimate, water relations, photosynthetic output, berry temperature, carbon distribution, and day/night recovery that would affect grape composition and wine quality. Optimum vine spacing appeared to be 1.8 m, both closer and wider spacing leading to limitations in physiological activity. Interactions amongst below- and aboveground growth and physiological parameters are comprehensively discussed with a focus on sustainability.

A nonparametric adaptive EWMA control chart for monitoring mixed continuous and categorical data using self-starting strategy

In the context of big data-driven smart manufacturing, data is often characterized by high dimensionality, numerous variables, and complex associations. As a result, mixed continuous and categorical data are increasingly common. In the case of data that consist of a combination of continuous and categorical variables with unknown distributions, the application of traditional parametric control charts for monitoring purposes becomes challenging. Therefore, a novel nonparametric adaptive exponentially weighted moving average (EWMA) control chart using a self-starting strategy is proposed in this paper. First, the process of converting continuous data into categorical data is conducted using the data categorization method. The log-linear modeling is subsequently employed to investigate the relationships between various variables. Next, a nonparametric adaptive EWMA statistic is constructed to monitor mixed continuous and categorical data, and the self-starting strategy is employed to gradually expand the size of the in-control (IC) dataset and to update the parameters in real time. Then, a numerical simulation is conducted to compare the IC and out-of-control (OC) performance of the proposed chart with other control charts. According to the simulation result, it can be concluded that the proposed chart offers a more effective means of detecting shifts in the production process. Finally, a concrete illustration of an authentic dataset regarding red wine quality is provided to further clarify the effectiveness of the proposed control chart in monitoring mixed continuous and categorical data.

Berry secondary metabolites and leaf physiological parameters are independently regulated by exogenous methyl jasmonate application in Sangiovese grapevines (Vitis vinifera L.)

The role of jasmonates as elicitor of secondary metabolites is well known, and many experiments have been conducted in grapevine to evaluate their effects on berry and wine quality. Even though most of these studies used foliar jasmonates applications, little investigations have been done to assess the effects on leaves which, in turn, may indirectly affect grape metabolism potentially involving a long distance signaling or crosstalk. In this experiment we jointly investigated the specific effect of jasmonates on grape berry secondary metabolites and leaf physiological parameters to better comprehend their elicitation mechanisms in grapevine. A 10 mM methyl jasmonate (MeJA) solution was applied during the lag-phase only on the leaves or only on the clusters and compared to an untreated control. The MeJA specifically affected leaf physiological parameters and berry metabolism in the treated area. When applied only on the leaves, gas exchange parameters and leaf efficiency were reduced, stimulating the senescence mechanisms, without affecting berry metabolism. On the contrary, MeJA applied on the clusters significantly delayed berry ripening, leading to hypothesize a re-route of the berry carbon resources through the biosynthesis of volatile organic compounds which were strongly increased, especially the monoterpenes in their glycosylated form.

Analysis of targeted phenolic ageing markers in Syrah red wines during bottle ageing: Influence of cork oxygen transfer rate

A Syrah red wine ageing experiment was set up during 24-months and the influence of four micro-agglomerated corks were investigated. Specific phenolic ageing markers were selected and hemi-synthesized: vitisin B, malvidin-ethyl-catechin, and epicatechin-sulfonate. A targeted quantification method of these markers was then developed and validated by using ultra-high performance liquid chromatography - triple quadrupole mass spectrometry (UHPLC-QqQ-MS) operating in MRM (Multiple Reaction Monitoring). Results showed a significant decline in native grape polyphenol levels (anthocyanins, flavanols) as ageing progresses while pyranoanthocyanins, ethyl-linked pigments, and flavanol-sulfonates content increased. The cork oxygen transfer rate emerged as a pivotal factor and had significant effects on polyphenolic concentration evolution but had no significant impact on flavanol-sulfonate formation. These results provide valuable insights into the chemical evolution ongoing during wine ageing, accentuating the pivotal role of cork stopper selection in preserving wine quality over time.