Wine Quality Research Articles

The Metabolomic Profiling of the Flavonoid Compounds in Red Wine Grapes and the Impact of Training Systems in the Southern Subtropical Region of China.

Flavonoids play an important role in forming wine grapes and wine quality characteristics. The flavonoids of three winter red wine grapes, Yeniang No. 2 (YN2), Marselan (Mar), and Guipu No. 6 (GP6), were analyzed by ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QQQ-MS). Furthermore, the flavonoids in GP6 grapevines using two types of training systems, namely, trellis (T) and espaliers (E), were also compared in this study. Overall, 196 flavonoid metabolites, including 96 flavones, 38 flavonols, 19 flavanones, 18 polyphenols, 15 anthocyanins, 7 isoflavones, and 3 proanthocyanidins, were identified. The flavonoid profiles were remarkably different among these three grape varieties, while they did not change much in the GP6 managed on trellis and espaliers. Grape varieties with different genetic backgrounds have their own unique flavonoid profiles. Compared with Mar-T, isoflavones and flavonols presented higher contents in GP6-T and YN2-T, which mainly contain glycitein, genistin, calycosin, kaempferide, isotrifoliin, and ayanin. The anthocyanin content was significantly higher in YN2-T than in the other two varieties. YN2 and GP6-T present a more stable color, with significantly more acetylated diglucosides and methylated anthocyanins in YN2-T and GP6-T than in Mar-T. Notably, GP6 had more varied flavonoids and the better characteristics to its flavonoid profile out of these three varieties, due to it containing a higher number of anthocyanins, flavone, and flavonols and the greatest number of different flavonoid metabolites (DFMs), with higher contents than YN2 and Mar. Compared with the trellis training system, the espaliers training system increased the content of flavonoids detected in GP6 grape berries; however, the composition of flavonoids strictly depends on the grape variety.

Soil Microbial Communities and Wine Terroir: Research Gaps and Data Needs.

Microbes found in soil can have a significant impact on the taste and quality of wine, also referred to as wine terroir. To date, wine terroir has been thought to be associated with the physical and chemical characteristics of the soil. However, there is a fragmented understanding of the contribution of vineyard soil microbes to wine terroir. Additionally, vineyards can play an important role in carbon sequestration since the promotion of healthy soil and microbial communities directly impacts greenhouse gas emissions in the atmosphere. We review 24 studies that explore the role of soil microbial communities in vineyards and their influence on grapevine health, grape composition, and wine quality. Studies spanning 2015 to 2018 laid a foundation by exploring soil microbial biogeography in vineyards, vineyard management effects, and the reservoir function of soil microbes for grape-associated microbiota. On the other hand, studies spanning 2019 to 2023 appear to have a more specific and targeted approach, delving into the relationships between soil microbes and grape metabolites, the microbial distribution at different soil depths, and microbial influences on wine flavor and composition. Next, we identify research gaps and make recommendations for future work. Specifically, most of the studies utilize targeted sequencing (16S, 26S, ITS), which only reveals community composition. Utilizing high-throughput omics approaches such as shotgun sequencing (to infer function) and transcriptomics (for actual function) is vital to determining the specific mechanisms by which soil microbes influence grape chemistry. Going forward, understanding the long-term effects of vineyard management practices and climate change on soil microbiology, grapevine trunk diseases, and the role of bacteriophages in vineyard soil and wine-making would be a fruitful investigation. Overall, the studies presented shed light on the importance of soil microbiomes and their interactions with grapevines in shaping wine production. However, there are still many aspects of this complex ecosystem that require further exploration and understanding to support sustainable viticulture and enhance wine quality.

Exploring Corbières red wine typicity: evaluation of the impact of winemaking processes on the chemical composition and organoleptic properties of wines from different terroirs

Aromatic and polyphenolic compounds play an important role in the quality of red wines, contributing not only to flavour, but also to colour, astringency and bitterness. To explore the influence of climate and oenological practices on the chemical and sensory profile of wines, red blends from five terroirs of the Corbières appellation were analysed, taking into account two production years (2018 and 2019). The wines were a blend of at least two of four main grape varieties: Syrah, Grenache, Carignan and Mourvèdre. Volatile compounds were evaluated by HS-SPME-GC-MS, while wine pigments and derived pigments were evaluated by spectrophotometric measurements. In addition, the wines were compared using a quantitative descriptive analysis sensory profile method. The percentage of the blend significantly influenced the polyphenolic and aromatic characteristics of the wines, showing distinct 'typicity' characteristics between sub-regions. Maceration techniques, on the other hand, did not did not allow us to discriminate between sub-regions, but enabled a better understanding of chemical and sensory differences between samples.

Effects of High-Hydrostatic-Pressure Treatment on Polyphenols and Volatile Aromatic Compounds in Marselan Wine.

This study investigated the effects of high-hydrostatic-pressure (HHP) treatment of varying intensity (100-600 MPa) and duration (10-30 min) on polyphenols and volatile aromatic compounds in Marselan red wine. The types and concentrations of polyphenols and volatile aromatic compounds were compared before and after HHP treatment; the results indicated that HHP treatment at 300 MPa for 20 min significantly increased the total polyphenol content to 369.70 mg/L, a rise of 35.82%. The contents of key polyphenols, such as resveratrol and protocatechuic acid, were significantly enhanced. Furthermore, while the total content of volatile aromatic compounds did not change significantly under this condition compared to the untreated samples, the concentration of ester compounds significantly increased to 1.81 times that of the untreated group, thereby enriching the floral and fruity aromas of the wine and effectively improving its aromatic profile and sensory quality. Principal component analysis (PCA) further validated the positive impact of HHP treatment on the flavor characteristics of Marselan red wine. These findings provide technical support for the use of HHP in improving wine quality.

A Comparative Study of Microbial Communities, Biogenic Amines, and Volatile Profiles in the Brewing Process of Rice Wines with Hongqu and Xiaoqu as Fermentation Starters.

Rice wine is primarily crafted from grains through saccharification and liquification with the help of Qu. Qu plays an important role in the formation of the flavor quality of rice wine. Hongqu and Xiaoqu represent two prevalent varieties of Qu that are typically utilized in the brewing process of rice wine and play a crucial role in its production. In this study, GC, GC-MS, HPLC, and metagenomic sequencing techniques were used to contrast the microbial flora, biogenic amines, and aroma characteristics developed during the fermentation of rice wines, with Hongqu and Xiaoqu being used as initiating agents for the brewing process. The results show that the content of higher alcohols (including n-propanol, isobutanol, 3-methyl-1-butanol, and phenethyl alcohol) in rice wine brewed with Xiaoqu (XQW) was significantly higher than that in rice wine brewed with Hongqu (HQW). Contrarily, the concentration of biogenic amines in HQW surpassed that of XQW by a notable margin, but tyramine was significantly enriched in XQW and not detected in HQW. In addition, a multivariate statistical analysis revealed distinct disparities in the constitution of volatile components between HQW and XQW. Hexanoic acid, ethyl acetate, isoamyl acetate, ethyl caproate, ethyl decanoate, 2-methoxy-4-vinylphenol, etc., were identified as the characteristic aroma-active compounds in HQW and XQW. A microbiome analysis based on metagenomic sequencing showed that HQW and XQW had different dominant microorganisms in the brewing process. Burkholderia, Klebsiella, Leuconostoc, Monascus, and Aspergillus were identified as the primary microbial genera in the HQW fermentation period, while Pediococcus, Enterobacter, Rhizopus, Ascoidea, and Wickerhamomyces were the main microbial genera in the XQW brewing process. A bioinformatics analysis revealed that the concentrations of microbial genes involved in biogenic amines and esters biosynthesis were significantly higher in HQW than those in XQW, while the content of genes relevant to glycolysis, higher alcohol biosynthesis, and fatty acid metabolism was significantly higher in XQW than in HQW, which are the possible reasons for the difference in flavor quality between the two kinds of rice wine from the perspective of microbial functional genes.

Characterization of wine polyphenols with a carbon/nanoparticle TiO2 electrode

The positive effects of polyphenolic compounds on the sensory characteristics of wine and human health indicate a great need for a simple, fast and easily accessible method to determine the content of polyphenols in wine. The aim of this study is the electrochemical characterization of polyphenolic compounds in natural wine samples using a modified carbon paste electrode with TiO2 nanoparticles (MCPE/npTiO2) and improved voltammo­gram processing to obtain indicative data for polyphenols. The most marked influence of the modification of CPE with TiO2 nanoparticles was an increased sensitivity to electrooxi­dation, which is reflected in an increase of the anodic peak current. Of the five tested poly­phenols, i.e., gallic acid (GA), caffeic acid (CA), catechin (CT), quercetin (QV) and resveratrol (RE), the current maximum of the first two oxidation peaks increased only for GA by a factor of about 2 and for CT by a factor of about 1.5. Of the three red wines, Vranac (VR), Merlot (ME), Cabernet Sauvignon (CS); three white wines, Graševina (GR), Temjanika (TE), Char­donnay (CS) and one rose wine, Belrose Mediterranée Rosé (RO) tested, an increase by a factor of about 2.5 was observed for two red wines (VR, CS) and by a factor of 1.5 for one red wine (ME), one white wine (GR), and the rose wine (RO), while no increase in the current signal was observed for one of the white wines (CS). The most significant increase in the voltam­metric signal of GA at the MCPE/npTiO2 compared to other studied polyphenols can be explained by its higher affinity for adsorption on TiO2 nanoparticles. The investigated modified electrode provides an improved, linear and reproducible voltammetric response in wine samples. Consequently, MCPE/npTiO2 represents a good basis for the further deve­lopment of an integrated sensor/data system with the possibility of a broader application for the detection of polyphenols, especially GA, as an aroma and visually relevant parameter in winemaking.

Investigating biological mechanisms of colour changes in sustainable food systems: The role of Starmerella bacillaris in white wine colouration using a combination of genomic and biostatistics strategies

This study explores the biological mechanisms behind colour changes in white wine fermentation using different strains of Starmerella bacillaris. We combined food engineering, genomics, machine learning, and physicochemical analyses to examine interactions between S. bacillaris and Saccharomyces cerevisiae. Significant differences in total polyphenol content were observed, with S. bacillaris fermentation yielding 6 % higher polyphenol content compared to S. cerevisiae EC1118. Genomic analysis identified 12 genes in S. bacillaris with high variant counts that could impact phenotypic properties related to wine color. Notably, SNP analysis revealed numerous missense and synonymous variants, as well as stop-gained and start-lost variants between PAS13 and FRI751, suggesting changes in metabolic pathways affecting pigment production. Besides that, high upstream gene variants in SSK1 and HIP1R indicated potential regulatory changes influencing gene expression. Fermentation trials revealed FRI751 consistently showed high antioxidant activity and polyphenol content (Total Polyphenol: 299.33 ± 3.51 mg GAE/L, DPPH: 1.09 ± 0.01 mmol TE/L, FRAP: 0.95 ± 0.02 mmol TE/L). PAS13 exhibited a balanced profile, while EC1118 had lower values, indicating moderate antioxidant activity. The Weibull model effectively captured nitrogen consumption dynamics, with EC1118 serving as a reliable benchmark. The scale parameter delta for EC1118 was 23.04 ± 2.63, indicating moderate variability in event times. These findings highlight S. bacillaris as a valuable component in sustainable winemaking, offering an alternative to chemical additives for maintaining wine quality and enhancing colours profiles. This study provides insights into the biotechnological and fermented food systems applications of yeast strains in improving food sustainability and supply chain, opening new avenues in food engineering and microbiology.

A Parallel Approach to Enhance the Performance of Supervised Machine Learning Realized in a Multicore Environment

Machine learning models play a critical role in applications such as image recognition, natural language processing, and medical diagnosis, where accuracy and efficiency are paramount. As datasets grow in complexity, so too do the computational demands of classification techniques. Previous research has achieved high accuracy but required significant computational time. This paper proposes a parallel architecture for Ensemble Machine Learning Models, harnessing multicore CPUs to expedite performance. The primary objective is to enhance machine learning efficiency without compromising accuracy through parallel computing. This study focuses on benchmark ensemble models including Random Forest, XGBoost, ADABoost, and K Nearest Neighbors. These models are applied to tasks such as wine quality classification and fraud detection in credit card transactions. The results demonstrate that, compared to single-core processing, machine learning tasks run 1.7 times and 3.8 times faster for small and large datasets on quad-core CPUs, respectively.

Wine law, sustainable innovation and the emergence of a wine constitution

Innovation is essential for addressing the current challenges of the wine sector and ensuring its sustainable future. Law plays a pivotal role in fostering and disseminating innovation. At the same time, innovations can present legislators with significant challenges and cause legal disruption. This paper evaluates the innovativeness of European Wine Law in light of the ongoing sustainability transformation. The focus of EU regulations is wine quality and authenticity, mainly through the protection of Geographical Indications (GIs). In Regulation (EU) 2021/2117, the EU legislator recently introduced new rules on fungus-resistant grape varieties, de-alcoholised products, and digital labelling. We describe the effects of these rules on the respective innovation systems and assess how, vice versa, these innovations exert disruptive pressure on wine law. While the legal framework shows remarkable flexibility, a reconfiguration seems necessary at the level of GIs. The sustainability transformation implies an openness to innovation even for traditional producers. Regulatory Sandboxes in GI product specifications could allow for more experimentation without compromising heritage. A wine constitution could guide the transformation towards a more resilient and sustainable wine system.

Study on the changes during the fermentation of the wine prepared from palm (Phoenix sylvestris) sap

The sugary sap of different palm trees is fermented to create palm wine, an alcoholic beverage. This work was aimed at studying the changes that occur during the fermentation process of wine made from the sap of the wild date palm species Phoenix sylvestris. At first, the best age of the palm tree was determined by observing total soluble solid and sap yield for 24 h and was found to be middle-aged palm plants (15–40 years old). Pure wine yeast (Saccharomyces cerevisiae SC22) and a natural starter culture were added to the palm saps, adjusting the total soluble solid (TSS) to 21.5° brix (°Bx). Total titratable acidity, pH, volatile acidity, reducing sugar, non-reducing sugar, total sugar, alcohol content, ester content, and aldehyde contents were the parameters under investigation. The statistical analysis showed significant (p ≤ 0.05) changes in the physico-chemical and volatile constituents of palm sap during the fermentation process in both systems. Sensory evaluation revealed that palm wine fermented with pure yeast culture was significantly superior to natural, spontaneously fermented wine. The acceptability test showed that the ideal characteristics of palm wine are cloudy in appearance, fruity in aroma, and sweet in taste.

Зависимость качества винопродукции сорта Красностоп АЗОС от подкормок разными группами веществ

Abstraсt. The impact of climatic changes in external conditions on the terroirs of the planet forces the grape plant to acquire new properties and characteristics that can negatively affect the quality of the wine made from them. Many countries around the world are faced with the problem of producing grape raw materials with high sugar content and insufficient ripening of phenols. One of the effective methods of reducing the negative impact of unfavorable terroir factors is the use of various fertilizers, including foliar fertilizers. In viticulture at the present stage, there is no systematic scientific knowledge about the mechanisms of action of certain drugs on the quality parameters of grapes and wine. The objects of study are preparations of various spectrums of foliar action: complex amino acid-humic fertilizer with vitamins and microelements of the CAGS brand; Chlorella extract (amino acid complex, highly effective natural biostimulator of plant growth.); Agrumax (mineral complex); biodux – growth regulator arachidonic acid, a complex of biologically active polyunsaturated fatty acids of the fungus Mortierella alpina; must and wine from the Krasnostop AZOS variety. The work used: modern instrumental and analytical methods for studying fruit crops and grapes; methods of technochemical and microbiological control in winemaking; wine parameters were determined according to GOST methods and original certified methods of the winemaking center of the NCFSCHVW; polyphenolic and anthocyanin substances in wine were studied using the technique of V.G. Gerzhikova, Research Institute "Magarach". Agricultural technology is generally accepted, adapted to the local terroir. Work on studying the impact of foliar preparations on the quality of must and wine, analysis of wine materials from the Krasnostop AZOS variety and their organoleptic evaluation, allows us to conclude that with an increase in the concentration of the extract, phenolic substances, and the total content of biologically active substances in it, the hygienic value and general quality of the wine itself; the highest tasting score was given to wine samples from the variants of treating grapes with foliar preparations from the group of biologically active substances: Chlorella algae extract and Biodux. Keywords: grape quality, microfertilizers, microwinemaking, wine quality, tasting analysis Financing source: The research was carried out within the State Task of Ministry of Science and Higher Education of the Russian Federation for the FSBSI NCFSCHVW.

Development of an efficient molecular-marker assisted selection strategy for berry color in grapevine

Marker-assisted selection (MAS) represents one of the most effective strategies to reduce costs and time in plant breeding programs. MAS benefits from the identification of markers in strong linkage disequilibrium (LD) with causative genes and from the development of fast, scalable, and reproducible screening techniques. In grape, berry color is a valuable trait, highly related to the sensory characteristics of fresh grape and wine quality.The present work aims to develop a MAS strategy to select skin color by High-Resolution Melting (HRM), a ‘close-tube’ method capable of detecting polymorphisms within PCR-amplified DNA fragments. To identify molecular markers associated with the berry skin color phenotypic trait, the total genome of 3 white-berry and 3 red-berry accessions were sequenced using Illumina technology and aligned to the reference genome PN40024 v4. The sequencing results revealed the presence of three highly polymorphic regions on chromosome 2 between 15 Kbp and 17 Kbp for red berry genotypes. HRM analyses were carried out on a total of 95 genotypes, 70 of which comprised a berry color segregating population: [‘Italia’ (white berry) x cv ‘Crimson Seedless’ (red berry)] and 25 genotypes belonging to a commercial grapevine germplasm collection consisting of 11 red and 14 white berry accessions. The HRM profiles of the three regions tested strongly correlated with the phenotypic trait of color.The results of this work represent an effective, fast, and reliable genotyping strategy that enables the discrimination of genotypes based on the presence or absence of berry pigmentation.

Non-Thermal Technology Approaches to Improve Extraction, Fermentation, Microbial Stability, and Aging in the Winemaking Process

Research into non-thermal wine processing technologies is constantly evolving due to the increasing trend towards high-quality, minimally processed, and preservative-free wines. Technologies such as high-power ultrasound, high hydrostatic pressure, pulsed electric field, ultra-high pressure homogenization, and, more recently, cold plasma are some of the best examples currently being explored. This article provides an overview of the latest scientific research into these five non-thermal technologies and their current status in relation to winemaking. By exploring the potential applications of these technologies, it becomes possible to enhance extraction, shorten maceration time, inactivate microorganisms and oxidative enzymes, reduce the addition of chemical additives, accelerate aging, improve wine quality, and much more. However, further experiments are necessary to better comprehend the short- and long-term impacts on the overall quality of the wines produced, especially in terms of sensory characteristics and consumer acceptance. Optimizing processing conditions and scaling up are also of paramount importance to ensure better performance of these technologies at the various stages of winemaking. Additionally, a combined technologies approach has been highlighted as one of the future directions to overcome the limitations of processing with a single technology.

Emotional response to sherry wines and its relationship with emotional intelligence, level of expertise and gender

Emotional elicitation during wine consumption is a complex fenomena based on subjective experience and influence by physiological, cognitive and behavioural changes. The present study used a quasi-experimental design to examine consumers’ emotional responses during blind tastings of sherry wines, considering variables such as consumer experience, gender and Emotional Intelligence (EI). 66 participants were classified as non-expert (34) and expert (32) consumers to participate in blind tastings. Their emotional responses were measured using the EsSense25 Scale and the Perceived Emotional Intelligence was assessed through the Trait Meta-Mood Scale. Few differences were observed on emotional elicitation based on gender or consumer experience (non-expert vs expert), however the interaction of these variables was a good predictor of emotional response variance. Wine type also has an effect on emotional response, emphasising the role of sherry wine characteristics in consumer emotions. Furthermore, the Emotional Attention, one of the three dimensions of Emotional Intelligence, was found as a good predictor for the emotional responses to wine consumption. This relationship may be a key factor in understanding the differences between responsible consumption and excessive consumption, as indicated by research focused on binge drinking.

Technological affinity index for interaction between lactic acid bacteria and Saccharomyces cerevisiae strains to modulate the fruity and floreal aroma of Catarratto wines

Microbial interactions during the fermentation process influence the sensory characteristics of wines. Alongside alcoholic fermentation, malolactic fermentation also plays a crucial role in determining the aromatic traits of wines. The time (t), rate (m) and volatile organic compounds (VOCs) of malolactic fermentation are linked to the interaction between yeasts and lactic acid bacteria. The study investigated the interactions between Lactiplantibacillus plantarum or Oenococcus oeni with Saccharomyces cerevisiae by using the Technological Affinity Index (TAIndex). The co-inoculation of L. plantarum/S. cerevisiae resulted in a higher TAIndex than the co-inoculation of O. oeni/S. cerevisiae conditions. A low TAIndex led to increased aromaticity of the wines. The time and rate of malolactic fermentation have a strong impact on the synthesis of VOCs with a high olfactory impact. Therefore, knowledge of the TAIndex could play a decisive role in improving winemaking planning to produce wines with higher fruit and floral perceptions.

Deciphering Terroirs’ Code: Vineyard Site Selection for Phenolic Performance in ‘Kalecik Karası’ Grape Cultivar (V. vinifera L.)

AbstractUnderstanding the complex interplay between environmental factors and grape quality is crucial for the viticulture industry, as it directly influences wine quality and the distinctiveness of products. This significance underpinned our comprehensive study, which aimed to dissect the relationships between ‘terroir’, including the altitude, regional climate, soil characteristics, vineyard management practice, and the composition of grapes in cv. ‘Kalecik Karası’ (Vitis vinifera L.). Six vineyard sites ranging from 115 to 1180 m altitude were studied. Total soluble solids (TSS, °Brix) titratable acidity, pH and color index of red grapes (CIRG) were evaluated as the main maturity indices and phenolic composition based on anthocyanin and tannin was analyzed. According to the results of the study, we deduced the critical importance of adopting region-specific viticultural practices tailored to the unique environmental conditions of each terroir. This approach not only optimizes grape quality but also accentuates the uniqueness of the wines produced, reflecting the inherent qualities of their origin. The highest altitude Nevşehir (1180 m) showed high levels of total and extractable anthocyanin highlighting the region’s favorable conditions for these compounds (355.26 mg kg−1 and 364.00 mg kg−1), while exhibiting the second lowest skin tannin (1979.40 mg kg−1 and 2180.78 mg kg−1) in both years. Particularly for cultivars like ‘Kalecik Karası’, our study demonstrated how specific terroirs could significantly affect their phenolic composition and, consequently, wine quality. By aligning viticultural practices with the distinct characteristics of each terroir, producers can enhance both the quality and distinctiveness of their wines. This emphasizes the necessity of ongoing research and adaptation in viticultural strategies to fully harness the potential of diverse grape varieties and terroirs, ensuring the production of high-quality wines that truly reflect their origin.

Effect of different deficit irrigation regimes on vine performance, grape composition and wine quality of the “Primitivo” variety under mediterranean conditions

Climate change represents one of the current major challenges and the improper use of water resources is an impeding threat. Agricultural research can play a crucial role by developing innovative strategies and techniques to reduce water use without affecting crop productivity and quality, particularly in grapevine growing in Mediterranean areas, as both productivity and wine quality are quintessential for the economic and ecologic sustainability of this crop. The present study aimed to define a deficit irrigation strategy for the “Primitivo” grapevine cultivar, taking into account the overall pathway of the vineyard performance in terms of leaf functionality, starch reserves, vine productivity, and wine quality. The trial was carried out in Southern-Italy on a three year-old, drip irrigated vineyard, imposing four deficit irrigation regimes for two consecutive seasons, consisting of 29 (T29), 55 (T55), 85 (T85) and 100% (T100) of crop evapotranspiration (ETC). Mild water restriction (T85) did not affect vegetative nor reproductive vine performance. Deficit irrigation at 55% ETC lowered leaf functionality, starch accumulation, vine vigour and yield, due to a reduction of cluster weight; however, wine acidity and phenolic compounds were increased. T29 further decreased yield, as also the number of clusters was reduced. The most water-stressed treatment revealed a low concentration of malic acid in the must and a consequent increase of the ethanol sensation in the wine. After 9 months ageing, T85 had the highest wine colour intensity suggesting this treatment as the most promising in terms of quality and quantity of wine as well as for water saving.

The impact of simultaneous inoculation with Torulaspora delbrueckii and Hanseniaspora uvarum combined with Saccharomyces cerevisiae on chemical and sensory quality of Sauvignon blanc wines.

Non-Saccharomyces yeasts have great potential in improving wine quality, showing personality characteristics, and highlighting the terroir of wine. In this study, we evaluated the impact of simultaneous inoculation with the non-Saccharomyces yeasts Torulaspora delbrueckii or (and) Hanseniaspora uvarum in combination with Saccharomyces cerevisiae (EC1118 or VL3) on the aromatic compounds and sensory quality of Sauvignon blanc wines. The growth of yeast groups in the alcoholic fermentation process was tracked using fluorescence in situ hybridization. The presence of non-Saccharomyces yeast notably impacted the distribution of S. cerevisiae and was related to the species of yeast. The co-fermentation of H. uvarum and S. cerevisiae improved the content of total esters, especially acetate esters. Simultaneous inoculation of T. delbrueckii or (and) H. uvarum significantly increased the content of total terpenes, especially linalool. Similar results were found for some higher alcohols and organic acids. Sensory evaluation showed that the wines mixed fermentation with H. uvarum had significantly tropical fruit aroma characteristics. Citrus and mineral notes, typical aroma characteristics of Sauvignon blanc wine, were enhanced by mixed fermentation strategies with T. delbrueckii or (and) H. uvarum and different S. cerevisiae. Hence, co-fermentation by T. delbrueckii or H. uvarum combined with S. cerevisiae could significantly improve the sensory quality of Sauvignon blanc wine.

Spontaneous vinification supports different microbiota, volatilome and leads to wines with different sensory attributes compared to vinifications inoculated with commercial and indigenous to vidiano cultivar Saccharomyces cerevisiae

Commercial Saccharomyces cerevisae yeasts are still the cornerstone of wine-making. However, use of indigenous S. cerevisae strains or spontaneous fermentations are gaining grounds. Still, we have limited understanding of the effects of S. cerevisiae strains on the composition and succession of vinification microbiota and its cascading effects on wine characteristics. We hypothesized that commercial or indigenous S. cerevisiae strains would lead to different vinification microbiota, volatiles, physicochemical and sensory attributes of wines. To verify this we employed vinifications inoculated with indigenous (W12, W13, W17) or commercial S. cerevisiae (GVS107, SH12) and one spontaneous (S). Amplicon sequencing and (GTG)5 analysis showed that fungal inocula dominated the inoculated vinifications, whereas the spontaneous supported a diverse community of Saccharomyces and non-Saccharomyces (NS) yeasts. The bacterial community didn't vary between vinifications, dominated by acetic acid bacteria (AAB), Burkholderia, Asinibacterium and Sphingomonas. The spontaneous fermentation showed a distinct volatilome compared to inoculated fermentations which didn't differ. The distinct fungal microbiota and volatiles in spontaneous vinification were reflected in the distinct oenological and sensory characteristics (nuts, herbaceous) of the wine compared to inoculated vinifications (fruits, blossoms). Saccharomyces were the key mediators of the volatilome in the inoculated fermentations, compared to spontaneous, where NS yeasts moderated volatiles.

Pulsed light treatment helps reduce sulfur dioxide required to preserve Malbec wines

Sulfur dioxide (SO2) has a long history of use as a preservative in wine production to prevent oxidation and microbial spoilage. However, sulfite sensitivities exist in some consumers that range from mild breathing irregularities to more severe allergic symptoms that can include anaphylactic reactions. These adverse effects have inspired the wine industry to develop alternative approaches to either lower or replace the use of sulfites. This study focused on assessing the efficacy of employing continuous Pulsed Light (PL) in conjunction with reducing SO2 applications to inactivate spoilage microorganisms and ensure optimal red wine preservation. Applying PL at an intensity of 4 J/cm2 to wine in combination with a 25 mg/L SO2 treatment generated a 12% and 22% reduction, respectively, in both the number of viable yeast and LAB cells, respectively, while having no substantial effects on color, changes in acidity, total phenolic, and anthocyanin contents after four months of aging. We conclude that PL processing of wine can help reduce the amount of SO2 needed to inactivate wine spoilage microorganisms and prevent loss of wine quality due to chemical oxidation. This combination of markedly reducing SO2 concentration use along with introducing non-thermal PL processing can be done effectively and simply to ensure a safer and stable final wine product for sulfite-sensitive consumers.