Search Results (147)

Bentonites used for wine clarification vary widely in their ability to remove proteins and alter wine composition, yet the role of their intrinsic properties remains unclear. To address this, eight commercial bentonites with diverse physico-chemical characteristics were analyzed. The doses required for complete protein removal and stabilization were determined and then applied to clarify a Malvazija istarska (Vitis vinifera L.) white wine. Clarified wines were compared with one another and with a non-clarified control using ICP-OES for elemental composition, HPLC-DAD for phenolic compounds, and HS-SPME-GC/MS for volatile compounds. Protein removal efficiency correlated positively with Na/Ca ratio, cation exchange capacity, swelling capacity, negative ζ-potential, and internal specific surface area, and negatively with particle size and external specific surface area. Sodium and calcium showed the greatest increases in wine concentrations. Effects on individual low-molecular-weight phenols were inconsistent, though all bentonites removed a fraction of total phenols. Volatile compounds, particularly esters, were significantly reduced. When compared on a per-gram basis, bentonites that were more efficient in protein removal also showed greater removal of phenols and volatile compounds; however, at full application doses, many of these differences diminished or reversed. Overall, the study advances understanding of bentonite–wine interactions and supports more informed selection of bentonites in oenological practice. Full article

We report a novel tablet-based reverse titration system for rapid, point-of-use measurement of water hardness, overcoming key limitations of conventional EDTA titration. Reagents are encapsulated in pullulan matrix giving two separate tablets. The first tablet contains the Eriochrome black T (EBT) and N-cyclohexyl-3-aminopropanesulfonic acid (CAPS) buffer, while the second encapsulates ethylenediaminetetraacetic acid (EDTA) disodium salt dihydrate. The system employs a trimodal detection strategy: qualitative screening via immediate color change with the EBT tablet, semi-quantitative estimation through combined tablet dissolution and adjusting the sample volume to a reference level, and quantitative determination using reverse titration, where water is gradually added until the red wine endpoint appears. This approach enhances interference tolerance from competing metal ions and improves accuracy over traditional methods. Testing with real water samples showed excellent agreement with standard titration. The tablets remain stable for over seven months, and the system eliminates the need for skilled personnel, laboratory equipment, or bulky instrumentation. This low-cost, user-friendly, and interference-tolerant platform enables rapid and accurate water hardness assessment at the point of use. Full article

Multiclass evaluation metrics derived from the confusion matrix—such as accuracy, precision, and recall—are widely used yet rarely formalized with respect to their structural invariance. This paper introduces a closed-form analytical framework demonstrating that core metrics remain stable under confusion matrix transposition and class label permutation. A minimal sufficient set of metrics is identified—Overall accuracy, Macro-averaged precision, Macro-averaged recall, and Weighted precision—from which all other commonly reported metrics can be derived. These invariance properties are established algebraically and validated numerically using both the Wine dataset and CIFAR-10 with a convolutional neural network. The results confirm robustness across models and datasets and clarify metric behavior under structural transformations. The proposed framework reinforces reproducibility and interpretability in multiclass evaluation, with implications for diagnostic screening, fraud detection, and classification audits. Full article

In the present paper, extracts from pomace after cherry wine production were used as biocomponents of antioxidant packages. In the study, the highest concentrations of polyphenolic compounds were obtained when a 50% ethanol solution was used as the extraction solution. The addition of extracts provided statistically significant (p < 0.05) changes in water vapor transmission for the films obtained. The WVTR results are at a very low level, as values ranging from 7.96 ± 0.33 [g/m² d] (sample 2) to 10.95 ± 0.33 [g/m² d] (sample 1) were obtained. The addition of extract also affected the oxygen barrier. Samples without extract addition showed an OTR value of 2.42 ± 0.23 [cm³/m² d 0.1 MPa]. A statistically significant (p < 0.05) reduction in this parameter was affected by the addition of extract to the matrix. Oxygen barrier properties ranged from 0.50 ± 0.05 (sample 3) to 0.94 ± 0.04 (sample 1), indicating high barrier properties of the packaging material. The addition of extracts caused an increase in opacity: films 3 and 4 were characterized by the highest value of the parameter, which was, respectively: 18.14 ± 27.02 and 18.97 ± 29.83 [%]. The research carried out in this study allows us to conclude that bioactive films with high application potential have been achieved and, in addition, represent a natural and ecological alternative to the materials currently used. Full article

The presence of pesticide residues in wine raises concerns about consumer health and regulatory compliance. This study evaluates the behaviour of seven pesticides (boscalid, penconazole, tebufenozide, kresoxim-methyl, trifloxystrobin, chlorpyrifos and lambda-cyhalothrin) during key stages of vinification, including clarification, fermentation, and racking, using liquid chromatography–tandem mass spectrometry. Penconazole, kresoxim-methyl and trifloxystrobin were not detected at the beginning of the vinification stage. Boscalid, chlorpyrifos and lambda-cyalothrin showed a reduction of 100% whit, a concentration below the limit of quantification at the end of the vinification stage. However, tebufenozide showed the lower elimination rate (88.1%), presenting a concentration at the end of the vinification process of 21.71 µg/kg. Experimental data confirm that pesticide concentrations progressively decline due to a combination of physicochemical transformations, adsorption onto solids, and biochemical processes. The clarification and racking stages are particularly important for reducing residues, primarily by removing suspended solids that adsorb pesticides. Fermentation also contributes to this reduction through microbial metabolism and enzymatic hydrolysis. The effectiveness of these stages depends on the pesticide’s solubility, chemical stability, and interactions with components in the wine matrix. Additionally, a risk assessment based on Acceptable Daily Intake and Estimated Daily Intake was performed to evaluate potential consumer exposure, showing lower risk for all pesticides studied. The findings emphasise the importance of optimising clarification and racking procedures, selecting effective fining agents, and refining filtration techniques to further enhance pesticide removal. Full article

Cancer remains a prevalent global health concern, with key factors such as diet, environment, and genetics playing significant roles in its progression. Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, play a critical role in cancer progression by degrading the extracellular matrix, thereby facilitating tumor growth and metastasis. Wine contains various bioactive compounds, including caffeic acid, gallic acid, kaempferol, naringenin, quercetin, myricetin, resveratrol, epigallocatechin gallate, riboflavin, and folic acid, which have shown promise in inhibiting cancer cell proliferation and metastasis. These compounds have been reported to downregulate the activity and/or expression of MMP-2 and MMP-9, thus potentially suppressing tumor progression. However, excessive alcohol consumption can lead to addiction and elevate the risk of various health complications, including fatty liver disease, cardiovascular damage, stroke, and kidney failure. Despite these concerns, moderate wine consumption has been associated with potential anticancer properties by restricting tumor growth and metastasis. In this review, we summarize and discuss how bioactive molecules in wine regulate MMP-2 and MMP-9 through bioactive compounds derived from wine and explore their implications for cancer treatment. Full article

This paper presents a simplified and computationally feasible multivariate extension. A correlation matrix is constructed using pairwise Spearman’s footrule correlation coefficients, and these coefficients are shown to jointly converge to a multivariate normal distribution. A global test statistic based on the Frobenius norm of this matrix asymptotically follows a weighted sum of chi-square distributions. Simulation studies and two real-world applications (a sensory analysis of French Jura wines and the characterization of plant leaf specimens) demonstrate the practical utility of the proposed method, bridging the gap between theoretical rigor and practical implementation in multivariate nonparametric inference. Full article

The simultaneous determination of 166 pesticides using dispersive liquid–liquid micro extraction combined with gas chromatography–tandem mass spectrometry and ultra-high performance liquid chromatography–tandem mass spectrometry (DLLME–GC-MS/MS+LC-MS/MS) is presented here. In this work, DLLME was extended to complex residues in the ginseng wine matrix. This study first focused on the selection of an appropriate solvent that enabled the dissolution of analytes from ginseng wine. The matrix-matched calibration curves showed good linearity in the range of 2–100 µg L⁻¹ for all pesticides, with coefficients of determination of 0.977–1. The mean recoveries were in the range of 3–124%, with 133 pesticides in the range of 60–130%, and the relative standard deviations (RSDs) were between 0.4% and 31.4%. The limits of detection (LOD) and limits of quantitation (LOQ) were within the ranges of 0.14–140 and 0.5–470 ng L⁻¹, respectively. Therefore, this analytical method contributes to residue analyses of 133 pesticides for the routine laboratory testing of ginseng wine. Research was also carried out by soaking the pesticide-positive samples in ginseng wine to monitor the migration and degradation of pesticides. The results showed that, the migration rates of thifluzamidewaslower than 60%, cyprodinil was 73.7, while azoxystrobin, pyrimethanil, carbendazim, dimethomorph, difenoconazole, pyraclostrobin, propiconazole, quintozene, pentachloroaniline, tebuconazole and phoximwere between 75% and 95%. Quintozene was more easily degraded into pentachloroaniline in the wine. Full article

Alcoholic beverages are loved by the majority of consumers because of their diverse characteristics and rich nutritional value; thus, ensuring their quality is necessary for maintaining the rapid development of the alcoholic beverage industry. Due to trace levels of various quality factors and the complexity of the beverage body matrix, pretreatment is usually required before analysis. Among the many pretreatment methods available, microextraction has attracted increasing attention because it aligns with the development direction of green chemistry. This review surveys advancements in microextraction techniques pertaining to three quality aspects in the most frequently consumed alcoholic beverages: baijiu and huangjiu (spirits) and wine and beer (fermented alcoholic drinks). Furthermore, new directions in their development are discussed. Full article

Background and Objectives: Resin composites are widely used in restorative dentistry due to their favorable mechanical properties and aesthetics. However, their clinical performance depends on factors such as chemical composition, microhardness, and exposure to environmental challenges like acidic beverages. Materials and Methods: This study evaluated the effects of coffee, red wine, and Coca-Cola on the surface microhardness and chemical composition of two resin composites (G-ænial A’CHORD and Omnichroma). A total of 40 disk-shaped specimens (20 per composite) were fabricated and divided into four groups: control, red wine, coffee, and Coca-Cola. Specimens were immersed in their respective solutions for 10 days, after which Raman spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy and Vickers microhardness testing were conducted to assess mechanical and chemical changes. Paired t-tests were performed to compare pre- and post-immersion values, with significance set at p < 0.05. Raman and FTIR spectroscopy confirmed structural changes, including peak shifts and intensity variations, particularly in polymer–matrix interactions and filler compositions. Results: The Vickers microhardness test revealed significant reductions in hardness for both composites after immersion, with Omnichroma showing a greater susceptibility to softening than G-ænial A’CHORD (p < 0.01). Red wine and coffee immersion resulted in the most significant decreases, indicating the strong impact of polyphenolic and acidic interactions on the composite structure. Conclusions: These findings indicate that prolonged exposure to acidic and staining beverages compromises the mechanical and chemical integrity of resin composites, with Omnichroma being more affected than G-ænial A’CHORD. The findings suggest that the selection of composite materials should consider resistance to staining agents, especially in high-risk oral environments. Full article

Underwater aging of alcoholic beverages has gained growing interest in recent years as a novel strategy for product differentiation. This study investigated the effects of 12 months of underwater aging at 13 m depth on the chemical, volatile, and phenolic profiles of wine-based liqueurs, compared to traditional cellar aging. Individual bottles were analysed using an E-nose, achieving 96% correct classification in the cross-validated confusion matrix. Chemical analysis revealed no significant differences in pH, ethanol content, total and volatile acidity. Although total phenolic content did not differ significantly, underwater-aged liquors exhibited higher levels of anthocyanins, suggesting reduced degradation of phenolic compounds in the anaerobic underwater environment. This was supported by higher levels of free alpha-amino nitrogen and total proteins, suggesting slower oxidation. As a result, underwater-aged liquors showed a lower b* index (yellowness), likely due to the reduced oxidation of red colour compounds. Underwater aging induced some changes in the volatile profile, with a significant increase in certain furanones and pyranones, such as 5-hydroxymethylfurfural, 4-hydroxydihydro-2-(3H)-furanone and 3,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one, responsible for strawberry, toasted, and caramel notes. This increased production could be attributed to the unique underwater environment, characterised by oscillating vibrations, blue-green light, lower and more constant temperatures and reduced oxygen levels. Full article

Self-Organizing Map (SOM) neural networks can project complex, high-dimensional data onto a two-dimensional plane for data visualization, enabling an intuitive understanding of the distribution and symmetric structures of such data, thereby facilitating the clustering and anomaly detection of complex high-dimensional data. However, this algorithm is sensitive to the initial weight matrix and suffers from insufficient feature extraction. To address these issues, this paper proposes an improved SOM based on virtual winning neurons (virtual-winner SOMs, vwSOMs). In this method, the principal component analysis (PCA) is utilized to generate the initial weight matrix, allowing the weights to better capture the main features of the data and thereby enhance clustering performance. Subsequently, when new input sample data are mapped to the output layer, multiple neurons with a high similarity in the weight matrix are selected to calculate a virtual winning neuron, which is then used to update the weight matrix to comprehensively represent the input data features within a minimal error range, thus improving the algorithm’s robustness. Multiple datasets were used to analyze the clustering performance of vwSOM. On the Iris dataset, the S is 0.5262, the F1 value is 0.93, the ACC value is 0.9412, and the VA is 0.0012, and the experimental result with the Wine dataset shows that the S is 0.5255, the F1 value is 0.93, the ACC value is 0.9401, and the VA is 0.0014. Finally, to further demonstrate the performance of the algorithm, we use the more complex Waveform dataset; the S is 0.5101, the F1 value is 0.88, the ACC value is 0.8931, and the VA is 0.0033. All the experimental results show that the proposed algorithm can significantly improve clustering accuracy and have better stability, and its algorithm complexity can meet the requirements for real-time data processing. Full article

Indoles are bioactive components found in wine products and are associated with yeast activity. Cava, a Spanish sparkling wine, is characterized by aging in contact with lees, making it a potential matrix for indoles. Therefore, the aim of this study was to determine the indole content in Cava produced at an industrial scale. Nine indoles were analysed by Ultra High-Performance Liquid Chromatography—Tandem Mass Spectrometry in Cava samples with different ageing times (n = 74). Significant amounts of tryptophan (2.3–1680.4 μg/L), tryptophan ethyl ester (0.1–5.2 μg/L), 5-methoxytryptophol (0.3–29.2 µg/L) and n-acetyl serotonin (0.3–2.3 μg/L) were determined. Tryptophan and tryptophan ethyl ester were positively correlated and decreased with ageing time. In fact, a concentration of less than 0.56 μg of the latter indole can become a marker of the most aged Cavas. The ageing time in contact with lees seems to play a key role affecting the indole content, since base wines show high amount of tryptophan and tryptophan ethyl ester while aged sparkling wines have values around the lower 95% confidence limit. Notably, the identification of tryptophan ethyl ester as a potential marker for aging in Cava suggests a new avenue for further research and quality assessment in its production. Full article

Ochratoxin A (OTA) exposure in food is very dangerous to human health. Therefore, the development of a fast and efficient technique for OTA removal has become an urgent research topic in the field of food safety. Nano Fe₃O₄ modified chitosan nanocomposite (nano-Fe₃O₄@CTS) was synthesized as a rapidly separable and safe adsorbent and was used to adsorb OTA in wine. FT-IR, XRD, and VSM characterization methods indicated that chitosan was successfully modified by Fe₃O₄ and exhibited good magnetism. The adsorption and kinetics isotherms between OTA and nano-Fe₃O₄@CTS were studied by the Langmuir equation and the pseudo-second order kinetics equation. The mechanism of OTA adsorption on nano-Fe₃O₄@CTS nanoparticles was the combined effect of physical adsorption and chemisorption. The negative ΔH°, ΔG° and ΔS° values proved that the adsorption was a spontaneous and exothermic process. Nano-Fe₃O₄@CTS with a high maximum adsorption capacity of 5018.07 ng/g at 25 °C can rapidly separate the matrix immobilized OTA from wine, and to a certain extent retains some of the wine quality after OTA removal. Full article

The Maillard reaction (MR) between sugars and amino acids, peptides, or proteins is understood to occur gradually during the production and aging of sparkling wines, where it contributes to caramel, roasted, and toasted aromas. Divalent metal ions can accelerate the MR, although this has not been previously reported in wine or wine-like conditions. In this work, the effect of calcium (Ca) and magnesium (Mg) ions on the concentration of 10 Maillard reaction-associated products (MRPs) was measured in modified sparkling base wine during accelerated aging at 50 °C for four weeks. Chardonnay base wine was modified by the addition of fructose (0.02 M) and a single amino acid (lysine, glycine, cysteine; 0.01 M) in combination with Ca²⁺ or Mg²⁺ at zero, low (10 mg/L), or high (50 mg/L) dose levels. MRPs were quantified by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC/MS), sugar concentration was measured by enzymatic assay, and amino acids and free metal ions were monitored by capillary electrophoresis. Fructose levels did not substantially decrease during aging despite increases in all MRPs, suggesting that trace sugars or α-dicarbonyl species present in the wine matrix likely play a greater role in MRP formation than fructose. Aging duration and amino acid content had a greater effect than metal addition on the composition of the MRPs. Treatments containing cysteine and 50 mg/L Ca²⁺ had elevated concentrations of benzaldehyde and furfural ethyl ether following 4 weeks of accelerated aging. This work identified key MRPs that increase during base wine accelerated aging and informs future research on the relationship between wine composition and aging markers. Full article