Free Sulfur Research Articles

Explore the impact of free sulfur dioxide on red and white wine

Explore the impact of free sulfur dioxide on red and white wine

A Multifunctional Secondary Based on Heterogeneous Co-MnO@NC for Depth-Induced Deposition and Conversion of Polysulfides in Li─S Batteries.

The conductive carbon-based interlayer, as the secondary current collector in the self-dissolving battery system, can effectively capture escaping cathode active materials, inducing deep release of remaining capacity. In the multi-step reactions of Li─S batteries, the environmental tolerance of the conductive carbon-based interlayer to polysulfides determines the inhibition of shuttle effects. Here, a modified metal-organic framework (Mn-ZIF67) is utilized to obtain nitrogen-doped carbon-coated heterogeneous Co-MnO (Co-MnO@NC) with dual catalytic center for the functional interlayer materials. The synergistic coupling mechanism of NC and Co-MnO achieves rapid deposition and conversion of free polysulfide and fragmented active sulfur on the secondary current collector, reducing capacity loss in the cathode. The Li─S battery with Co-MnO@NC/PP separator maintains an initial capacity of 1050mAhg-1 (3C) and excellent cycle stability (0.056% capacity decay rate). Under extreme testing conditions (S load = 5.82mgcm-2, E/S=9.1µLmg-1), a reversible capacity of 501.36mAhg-1 is observed after 200 cycles at 0.2C, showing good further practical reliability. This work demonstrates the advancement application of Co-MnO@NC bimetallic heterojunctions catalysts in the secondary current collector for high-performance Li─S batteries, thereby providing guidance for the development of interlayer in various dissolution systems.

Simultaneous Determination of 8 Antioxidants and Free Sulfur Migrating from Container Closure System into Antibody Drug using High Performance Liquid Chromatography

<p>Background: The additives from container closure systems used in biopharmaceuticals, including antioxidants and vulcanizing agents, may leach into drug products during production or storage and result in patient exposure. Thus, there is an urgent demand for developing a robust and sensitive method for the simultaneous determination of these additives. </p> <p> Method: An approach utilizing vortex-assisted liquid-liquid microextraction coupled with highperformance liquid chromatography has been developed for the simultaneous determination of 8 antioxidants and free sulfur in biopharmaceutical samples. The extraction parameters, such as the choice of extraction solvent, HCl volume, vortex time, and disperser solvent, were optimized to ensure maximum extraction efficiency. </p> <p> Results: The optimized method was validated successfully, exhibiting acceptable recovery rates ranging from 89.2% to 109.0%, excellent repeatability (2.9% to 5.1%, n=6), and intermediate precision (3.7% to 5.9%, n=12), and satisfactory linearity with an R2 value of 1.000 for all the additives. Additionally, the limits of detection and quantification were determined to be in the range of 1.9– 30.0 μg/L and 7.5–120.0 μg/L, respectively. </p> <p> Conclusion: The proposed method was effectively applied to the analysis of additives in biopharmaceutical samples.</p>

Assessment of Wine Quality, Traceability and Detection of Grapes Wine, Detection of Harmful Substances in Alcohol and Liquor Composition Analysis

Abstract: Wine production is the result of the interaction between various strains and grapes, and its good quality is also affected by many factors. Aureobasidium, Cladosporium, Candida, Filobasidium, Hanseniaspora, Hannaella, Saccharomyces, Wickerhamomyce, Alternaria, Starmerella, Acetobacter, Papiliotrema, Bradyrhizobium, Leuconostoclia, Gluconobacter, Comamonas, and Massilia, are significantly correlated with changes of physiological properties and volatile compounds. Phenolic compounds, shortened as phenolics, are a vital parameter to the quality of wine, and wine phenolics include two main families: non-flavonoids, which consist of hydroxybenzoic acids (HBAs), hydroxycinnamic acids (HCAs), and stilbenes, and flavonoids, comprising flavonols, flavan-3-ols, and anthocyanins. Wine quality is determined by either sensory tests or physicochemical tests, and the latter analyse the wine’s chemical parameters such as sugar, pH, and alcohol level. The most important constituents found in wine are Terpenes; Aldehydes, Pyrazines, Esters, Ketones and diketones, Mercaptans, and Lactones. In wine quality analysis, the most chief variables are volatile acidity, alcohol, sulphates, citric acid, density, total sulfur dioxide, chlorides, pH, fixed acidity, free sulfur dioxide, and residual sugar. Some classifiers utilized for wine quality prediction in machine learning are: k-Nearest Neighbor (KNN), Random Forest, Decision Tree, Support Vector Machines, Linear Regression, Stochastic Gradient Descent, Artificial Neural Networks (ANN), and Naive Bayes. This article is aimed to review wine quality parameters, detection and traceability of wine, and detection of harmful substances in alcohol and liquor composition analysis.

The use of chitosan and an inactivated yeast to reduce the amount of sulfur dioxide in wine

This study aims to evaluate the sulfur dioxide dynamics in two wines, dry white wine Fetească albă and dry red wine Fetească neagră made in Târnave vineyard, and to observe their evolution after application of Bactiless and Longevity to lower the level of SO2. The wines from 2020 harvest were produced using traditional winemaking techniques. The experimental variants were: Control, Longevity (20, 30, 40, 0, and 40 g/hL) with Bactiless (20, 35, 50, 50 and 0 g/hL). For all the samples studied in this work, it was determined a decrease concentration of free and total sulfur dioxide. The best results obtained for the Fetească albă wine was the decrease of free SO2 from 35.00 mg/L to 25.33±0.60 mg/L and total SO2 from 120.50 mg/L to 117.50 mg/L by using 50 g/hL of Bactiless (CFAV4). For the Fetească neagră wine, the best results obtained were the decrease of free SO2 from 32.50±0.29 mg/L to 14.83±0.18 mg/L and total SO2 from 85.00±0.87 mg/L to 75.00±0.86 mg/L by adding 40 g/hL of Longevity and 50 g/hL of Bactiless (CFNV3). With an allowed SO2 concentration, the evaluated wines maintained their varietal characteristics and organoleptic properties.

CHARACTERIZATION OF FATTY ACID ETHYL ESTER BIODIESEL (CWO100) PRODUCED FROM COMPOSITE WASTE OILS, ETHANOL AND KOH

There is an urgent need to convert Composite waste oils (CWOs) from domestic and industrial sources using circular system thinking approach due to the growing concern of their socio-economic, environmental and governance effects and impacts of increased human anthropogenic activities. CWO was first pre-treated by sieving, heated to reduce moisture/water concentration and the acid value lowered with the addition of sufficient KOH, then base transesterification reaction with ethanol (1:1), 1% KOH at 700C for 2 h. The physio-chemical and fuel properties of the CWO100 was analyzed using standard analytical methods, and the data statistically using SPSS version 20.0. CWO100 (FAEE) has lowest value of water and sediment, acid value, free fatty acid, carbon residue and sulphur, and the highest values for viscosity, specific gravity, density, colour, flash point, iodine. Most of its parameters are within the ASTM/EN standards except in CWOs that requires pre-treatment. CWO100 is better than petroleum diesel and can be applied in diesel engines, plants with little or no modification as a major alternative now and thereafter.

Sensory attributes and quality perception of red natural wines: a comparative study in Spain and France

Although the definition of natural wine remains contested and still lacks official recognition, it can be broadly described as a wine made with organic or biodynamic grapes without oenological additives in the cellar and minimal intervention in all winemaking stages. Despite growing interest in natural wines, uncertainty prevails about their sensory and quality attributes among both consumers and experts. In light of this research gap, this study aims to determine, first, if there are specific sensory dimensions allowing to differentiate natural wine as a wine category from conventional wines; second, if this sensory dimension affects the perception of the quality; and third, to characterise the physicochemical differences in terms of basic oenological parameters between natural wines and their conventional counterparts. To do so, 24 red wines (12 self-defined as natural and 12 conventional wines) were sensory and chemically characterised. The sensory evaluation was first carried out by winemakers from Spain. It consisted of a descriptive task (labelled sorting task) followed by a quality evaluation under two conditions: with and without information regarding the production method. A second panel of French experts carried out the same quality assessment, also with and without information. The aim was to find out whether expectations existed linked to each type of wine and to explore potential cross-cultural effects. The results of the labelled sorting task showed that natural wines tended to be different from conventional wines, but the difference was not clear-cut. However, natural wines were perceived to be of lower quality than their conventional counterparts, both with and without the information provided, regardless of the origin of winemakers. Results of the chemical analysis showed that natural wines presented higher values for volatile and total acidity and turbidity, while they had lower values for total and free sulphur. The study points to the existence of sensory dimensions with an impact on overall quality associated with the production method.

Observation and comparison of gas formation during holmium:YAG laser lithotripsy of cystine, uric acid, and calcium oxalate stones: a chromatographic and electron microscopic analysis.

The primary aim of the present in vitro study is to analyze the chemical content of the bubbles occurring during the fragmentation of cystine stones with both the high-power and low-power holmium:YAG (Ho:YAG) lasers. The secondary aim is to discuss their clinical importance. Three types of human renal calculi calcium oxalate monohydrate (COM), cystine, and uric acid were fragmented with both low-power and high-power Ho:YAG lasers in separate experimental setups at room temperature, during which time it was observed whether gas was produced. After laser lithotripsy, a cloudy white gas was obtained, after the fragmentation of cystine stones only. A qualitative gas content analysis was performed with a gas chromatography-mass spectrometry (GC-MS) device. The fragments in the aqueous cystine calculi setup were dried and taken to the laboratory to be examined by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and X-ray diffraction analysis. No gas production was observed after fragmentation in the COM and uric acid stones. Free cystine, sulfur, thiophene, and hydrogen sulfide gas were produced by both low-power and high-power Ho:YAG laser lithotripsy of the cystine stones. In the SEM-EDX mapping analysis, a free cystine molecule containing 42.8% sulfur (S), 21% oxygen (O), 14.9% carbon (C), and 21% nitrogen (N) atoms was detected in the cystine stone experimental setup. The evidence obtained, which shows that hydrogen sulfide emerges in the gaseous environment during Ho:YAG laser fragmentation of cystine stones, indicates that caution is required to prevent the risk of in vivo production and toxicity.

Foliar Spray with Selenium to Mitigate the Impact of Water Stress on Chemical, Enzymatic, and Hormonal Parameters of Garlic Allium sativum L.

The current research explored the beneficial role of selenium (Se) in alleviating the negative impacts of water stress on the chemical, enzymatic, and hormonal parameters of garlic plants via manipulating chemo-physiological mechanisms. A field experiment was executed at the research station of the Faculty of Agriculture, University of Kufa, Iraq in September 2022 using a randomized complete block design with three replicates based on a strip-plot system. Three water levels (100%, 80%, and 60%) were set up in the whole plots while foliar application of selenium (Se) with three concentrations (0, 10, and 20) mg.L-1 were assigned to the subplots. Our findings revealed a significant increase in the leaf content of free proline acid, sulfur, and ABA, as well as an increase in the activity of the antioxidant enzymes SOD and CAT when reducing irrigation levels from (100% to 60%) of the water requirement. While there was a significant decline in the plant hormones GA3 and IAA content in garlic leaves @ (60%) level of irrigation. The plants treated with foliar selenium @ (20 mg.L-1) enhanced most of the studied characteristics of garlic plants grown at different water levels. Moreover’ the full water requirement in combination with foliar Se @ (20 mg.L-1) provided the highest values of GA3 and IAA which were both comparable to the interaction treatment of water level @ (80%) and foliar Se @ (20 mg.L-1).

The effect of oil raw material composition in the synthesis of bio‐sorbents based on inverse vulcanization on the ability to remediate hydrocarbon‐contaminated water. A novel method for decontaminating water/fuel emulsions

AbstractSolid crosslinked biopolymers made by inverse vulcanization of soybean (PSB) or sunflower (PSF) oil with sulfur are characterized and tested to decontaminate water from hydrocarbons (HC): gasoline, diesel, two lubricant oils, and water/gasoline emulsion. The physicochemical structure of the biopolymers is studied by FTIR spectroscopy, Differential scanning calorimetry, contact angle measurement, and mechanical testing. Also, the morphological structure is analyzed by scanning electron microscopy. Moreover, the polymer decontamination capability and reusability are tested gravimetrically. Both biopolymers are formed by CS bonds, and their elastic behavior dominates. However, PSF is more hydrophilic, has a larger amount of free sulfur and a less compact structure, and also sorbs ca. 60% more HC than PSB. The results indicate that the unsaturated feedstock has a strong effect on the polymer structure and the capacity to remediate contaminated water or solids. Also, both materials can be reused to remediate water for more than five consecutive cycles. In addition, inverse vulcanization of oils and sulfur is an ecological way of obtaining environmentally‐improved materials with great potential and applications, providing a complete atomic economy and high performance to remediate water from water/HCs dispersed and, more importantly, from water/gasoline emulsions.

In-situ Formation of Sulphur-Trapped Petroleum Coke via Thermal Cracking of Vacuum Residue: A Practical Approach to Reduce Environmental Pollution

Environmental regulations restrict the use of high-sulphur petroleum coke as a solid fuel due to the emission of a substantial amount of sulphur oxides (SOx) upon combustion. Therefore, the free sulphur present in petroleum coke needs to be reduced to achieve lower SOx emissions. This paper describes a novel and efficient method for the trapping of free sulphur in petroleum coke during its formation from vacuum residue in the presence of an additive. Among the various additives tested, calcium oxide (10 wt%) was found to be most effective for maximum trapping of free sulphur in petroleum coke. This sulphur-trapped petroleum coke reduces SO2 emissions by 67% upon combustion; hence, it can be used as a better fuel than regular high-sulphur petroleum coke. Thus, by replacing regular petroleum coke with this newly developed sulphur-trapped petroleum coke, environmental pollution can be reduced significantly.

A FUNDAMENTAL STUDY ON CYCLIC TETRASULFIDE AS A SULFUR DONOR AND CO-AGENT FOR RUBBER CROSSLINKING

ABSTRACT Sulfur donors are used commonly in rubber crosslinking, usually in conjunction with elemental sulfur. In the crosslinking process, sulfur donors release in situ free sulfur. The difference between two sulfur donors, bis(triethoxysilylpropyl)-tetrasulfide (TESPT) and cyclic tetrasulfide (CTS), both of which contain at least one tetrasulfidic group in the molecule, is analyzed. Chemical model studies are deployed to assess the chemical reactivity of the two molecules. The difference in reactivity of the two sulfur donors was observed in chemical model studies in reaction with 2,3-dimethyl-2-butene, as followed by Raman spectroscopy, gas chromatography coupled with mass spectroscopy, and nuclear magnetic resonance analysis of the products of reaction. These studies represent a fundamental analysis and comparison between the two tetrasulfidic compounds, and the findings of these experiments can be extrapolated to crosslinking processes in rubber.

Milk volatilome as affected by somatic cell count in Holstein cows

The aim of the current trial was to study the impact of a high somatic cell count (SCC) on milk volatilome of fresh raw milk, and its evolution during storage of processed fluid milk. Six Holstein cows were selected from our research dairy herd based on test-day SCC records. Three cows were used to produce low-SCC milk (20 × 103 cells/mL). The three other cows had one-quarter infected by Staphylococcus aureus. Infected and healthy udder halves were milked separately, and high-SCC milk was standardized to 400 × 103 cells/mL by mixing these two milks. The profile of milk volatile organic compounds (VOCs) was determined on raw milk and during the storage of processed milk. The processing included a standardization to 3.25% fat, followed by homogenization, and thermization (65 °C/30 min). This procedure was repeated four times over a period of 7 days. A total of 40 VOC were identified using the solid-phase microextraction technique followed by gas chromatography separation, mass spectrometry analysis, and database search. These VOC were grouped into seven different families, including alcohols (n = 4), free fatty acids (n = 5), sulfur compounds (n = 3), esters (n = 7), ketones (n = 7), aldehydes (n = 12), and aromatic hydrocarbons (n = 2). In raw milk, high SCC was associated with a tendency for lower concentrations of ethyl-hexanoate (P = 0.07), acetone (P = 0.06), and benzaldehyde (P = 0.07) and lower concentrations of trans-2 hexenal (P = 0.04). On the contrary, high SCC was associated with a tendency for greater concentrations of acetic acid (P = 0.09) and hexanoic acid (P = 0.07) and greater concentrations of 2-nonanone (P = 0.02) and pentanal (P = 0.01). Concentrations of most VOC increased during the storage of processed milk. Lower concentrations of butanoic acid (P = 0.09; tendency) and ethyl hexanoate (P = 0.04), and greater concentration of 1-ocen-3-ol (P < 0.01) were observed in high-SCC milk at all times of storage evaluated. Increases in concentrations over time were less pronounced for ethanol (P < 0.01), ethyl butanoate (P = 0.05), and propanal (P = 0.10) in high SCC as compared with low SCC milk. In conclusion, an increase in SCC has a limited effect on milk volatilome, when a SCC standard of 400 × 103 cells/mL for bulk milk is respected.

Wine acidification methods: a review

Global warming is directly linked to a lower concentration in organic acids in grape berries, leading to higher pHs in wine. Because of this lack of acidity, many important factors are impacted, as wine acidity and pH play a crucial role in various equilibriums. Indeed, the lower acidity and the higher pH modify the parameters of wine, such as free and molecular sulfur dioxide availability, colour and sensory aspects. Therefore, it is an ongoing challenge for winemakers to deal with wine acidification and thus preserve wine physico-chemical properties and prevent early spoilage due to microbiological instability induced by high pH. Different acidification methods are allowed by the OIV, chemical acidification being one the most common, followed by physical acidification and microbiological acidification. This review examines these three methods of acidification. The first part details chemical acidification and gives a complete description of various organic acids used in winemaking, and their different properties and regulations; the second part focuses on physical acidification, such as cation exchange resins and electrodialysis; and the last part briefly reviews the novelty of microbiological acidification in wine.

Качество и безопасность продукции в процессе хранения в системе «вино – упаковка, укупорка»

Poor packaging often affects the quality and safety indicators of wine during storage. The need to preserve and prolong wine stability during long-term storage requires a comprehensive study of processes that occur in wines packaged and capped in various ways.&#x0D; This research featured 56 samples of white and red dry wines, which were bottled in four types of packages and stopper for 18 months. The effect of synthetic and natural stopper methods involved a model system that simulated the main composition of wine in line with the EAEU standards. The contents of free SO2 and dissolved oxygen, as well as the microbiology of natural corks, were studied using standard methods. The analysis of volatile substances relied on gas chromatography, mass spectrometry, and solid phase micro-extraction.&#x0D; The study recorded critical changes in the quality of wine products, characterized by increased oxidation markers and low free sulfur dioxide, which fell below 10 mg/dm3. In polyethylene terephthalate bottles, these changes occurred after 12 months of storage, while it took them 18 months to develop in multilayer bags and combined packaging materials. The components of natural and artificial plugs of microbial and chemical origin entered the model systems after 10 days of contact. The microbiological contamination was twice as high as the permissible level. The migration of microbial and chemical substances into the wine samples spoiled their quality and safety.&#x0D; The effect of packaging on the oxidative processes in white and red dry wines during storage resulted in different concentrations of dissolved oxygen and sulfur dioxide. The results can help wine producers to choose the most appropriate packaging and stopper means depending on the wine sort and its subsequent storage conditions. Alternative types of packaging proved to have a limited shelf life.

The exploration of the inverse vulcanization mechanism of tung oil by controlling the oxygen and moisture presence during reactions

Inverse vulcanization is a cost-effective method for producing high sulfur-content copolymers by combining elemental sulfur with organic monomers, which has rapidly gained popularity due to its simplicity of synthesis and wide range of applications. Although numerous examples of sulfur-rich copolymers have been synthesized at different reaction rates and temperatures using various monomers, the precise reaction mechanism remains unclear. In this paper, we used tung oil containing conjugated triene as a monomer to synthesize sulfur-rich copolymers under six different reaction conditions and investigate the effects of oxygen and moisture. Our study, which employed DSC, XRD, 1H NMR, and XPS characterization methods, revealed that oxygen accelerated the reaction rate and decreased the free sulfur content of the products, while moisture shortened the gel times but increased the free sulfur content. These findings confirm that reverse vulcanization involves two simultaneous mechanisms: the free radical mechanism and the anion mechanism. With regard to the radical mechanism, we discuss the source, ease, and reactivity of radicals and show that the creation of radicals depends on the second monomer rather than sulfur. Tung oil not only acts as a comonomer in the reaction but also plays an initiating role in promoting the dissociation of sulfur chains to generate free radicals for addition of non-conjugated double bonds. The effect of the anion mechanism exceeds that of the radical mechanism once certain factors are stimulated, such as the presence of metal ions and sulfide ions. Understanding the detailed mechanisms involved in inverse vulcanization is essential for selecting optimal monomers, which can enhance not only the synthesis process but also the properties of sulfur-rich materials.

Trade policy uncertainty and pollution emissions of export enterprises—The case of China‐ASEAN free trade area

AbstractWe propose a theoretical framework to illustrate the impact of trade policy uncertainty on pollution emissions of export enterprises and the underlying mechanism. The magnitudes of the effect and the proposed channels are empirically estimated using the case of the formal establishment of China‐ASEAN free trade area and sulfur dioxide (SO2) emission intensity as a measure of pollution emission intensity. Our analysis relies on high‐precision micro enterprise‐level data and the difference‐in‐difference methodology. The results show that China‐ASEAN free trade area effectively reduced the trade policy uncertainty and the SO2 emission intensity of Chinese enterprises exporting to ASEAN. The study also shows that the export enterprises of different trade modes, ownership types, regions, factor intensity, and pollution intensity industries show significant heterogeneity in the extent of the reduction in the SO2 emission intensity. The mechanism test reveals that the trade policy uncertainty decline mainly reduces the emission intensity of SO2 by raising the competitive and learning effects. The contribution of the learning effect is higher and accounts for 32.54% of the total effect. In addition, through dynamic decomposition at the industry level, we found that the contribution rate of resource allocation effect among enterprises in reducing the total emission intensity of SO2 of enterprises exporting to ASEAN at the industry level is 52.22%. This effect is perhaps the most significant way trade policy uncertainty impacts the SO2 pollution emission intensity.

Kinetics of oxygen consumption, a key factor in the changes of young wines composition

The oxygen that a wine receives during the winemaking process defines its properties. The aim of this work was to evaluate the oxygen consumption capacity of wines and its influence on the modification of their composition. This preliminary work evaluated the changes after 3 months in the chemical composition of twenty-seven Spanish commercial red, white and rosé wines after their air saturation and oxidation process at 35 °C for 7 days. All the wines studied were high oxygen consumers, while the white and rosé wines showed greater variability according to their chemical composition. Wines that consumed a lot of oxygen did so quickly or slowly, while wines that consumed little oxygen did so slowly. All the wines showed a significant decrease in ethyl esters of straight-chain fatty acids (50–58%), ethyl esters of branched-chain fatty acids (48–56%) and alcohol acetates (34–65%) content, and a significant increase in Strecker aldehydes (24%) because of oxygen consumption. This paper presents a preliminary approach to determine the oxidation tendency of different wines showing the importance of controlling the winemaking processes that can increase oxygen availability and of establishing the minimum appropriate level of free sulfur dioxide.

Changes in selected chemical and sensory parameters during aging of red wines produced in Poland

The study of the chemical composition of wines is of continuing interest to researchers, despite extensive knowledge about it. Many analyses focus on the chemical transformations that take place in this beverage as it ages. This study aimed to analyze changes in parameters such as free SO2 concentration, acidity, pH, the concentration of selected organic acids, total polyphenol concentration, and FRAP in five red wine varieties: Rondo, Regent, Cabernet Cortis, Acolon, and Zweigelt produced in Poland which were aged for 3 years. The study also included a sensory analysis of wines. The results indicated that, despite the relatively short aging time of the observed wine, the changes were significantly noticeable. The flavors of the wines, as well as their aromas, evolved, resulting in higher scores in sensory evaluation. Parameters such as free sulfur oxide (IV) concentration, antioxidant activity, and tartaric acid, acetic acid, and citric acid concentrations changed significantly. In addition, an analysis of the results was carried out using the PLS method, in which the relationships between the parameters determined were revealed. Research carried out indicates for the first time that Polish red wines have a relatively high potential for long aging.

White Wine Quality Prediction and Analysis with Machine Learning Techniques

The wine originated 7,500 years ago, and it is one of the most popular alcoholic beverages in the world today. With modern advances in production processes, the quality of wine has been significantly improved. White wines can be graded by measuring various physical and chemical quantities. In reality, it is very rare for white wines to have dramatic quality differences, so precisely capturing these important characteristics will be difficult. In addition, the available dataset for wine quality is relatively small and imbalanced, so it is not easy to train a machine learning model for wine quality prediction. This paper explores the applicability of applying logistic regression machine learning models for wine quality prediction. The Synthetic Minority Oversampling Technique (SMOTE) algorithm is applied to address the imbalanced data issue. The key features in wine production are analyzed to the physical or chemical quantities that are most likely to influence the quality of white wines. In several tests, the random forest model gives good results, and free sulfur dioxide, chlorides, and fixed acidity are the most likely characteristics to influence the quality of white wines.