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•Novel application of front-face fluorescence spectroscopy in wine analysis.•Third-order multivariate calibration was used to resolve catechin mixture.•MCR-ALS showed best performance ...in wine analysis.
In this work, an analytical approach based on third-order multivariate calibration and front-face fluorescence spectroscopy to determine the levels of (+)-catechin and (-)-epicatechin in wine samples was evaluated. An extra reaction mode (pH gradient) was incorporated into excitation-emission fluorescence second-order data, leading to higher predictivity and selectivity for catechin detection. Application of a Multivariate curve resolution-alternating least squares (MCR-ALS) algorithm resolved the systems, even in the presence of uncalibrated interferences, and yielded suitable figures of merit. Through the method, the level of (+)-catechin was directly determined, and the concentration of (-)-epicatechin was determined by the difference in total catechins (Epi + Cat) between synthetic samples. Finally, the levels of catechin were satisfactorily determined in real wine samples at mg L-1 levels with minimal sample treatment and in accordance with a reference method based on chromatographic separation.
Winemaking is an important agricultural economic activity worldwide, and variation in terroir gives birth to unique wines with different phenolic properties that reveal characteristics of each ...region, variety and vintage. We have comprehensively analyzed the phenolic components and antioxidant properties of 108 Chinese wines from five regions and four varieties produced from 2003 to 2019 by the LC-IM-QTOF-MS assay and multivariate statistical analysis. The results showed that the varieties of Cabernet Sauvignon, Cabernet Gernischt, and Merlot could be traced in Chinese red wines through the concentration of tannins. PCA showed that the first two principal components of the monomeric phenols explained 97.95% of the variance, and three regression variables were identified: (+)-catechin (CA), (−)-epicatechin (EC), and gallic acid (GA). CA and EC proved to be more stable than GA in different vintages. A cluster heatmap analysis showed that regional origin was significantly correlated with the phenolic content related to the antioxidant properties of the wine. The result reveals the similarities and differences in Chinese wines according to their regional origin, variety, and vintage.
•(+)-Catechin and (−)-epicatechin are more stable than gallic acid across different vintages.•Regional origin of wine correlates with the phenolic content related to antioxidant properties.•The regular variations of sensory evaluation of Cabernet Sauvignon wines from 2003 to 2019 were discussed.•LC-IM-QTOF-MS was used to assay 17 monophenols in 108 wines.
In the present work, we have studied the effect that some extraction techniques, such as ultrasound or microwaves, produce on the aroma of red wines, when applied to processes of extractive nature, ...such as pre-fermentative maceration or ageing with oak chips (Spanish oak – Quercus pyrenaica and French oak – Quercus robur). The volatile profile has been studied by means of gas chromatography coupled with olfactometric and mass spectrometric detection. Sensory analysis of all the wines produced has also been conducted. Although no indications were found to show that the pre-fermentative treatment with microwaves or ultrasound modified the sensory profile of the wines, the application of such energies during the ageing phase showed some positive trends at sensory level, also confirmed by the olfactometric measurements. The application of ultrasound during the ageing of the wines resulted in a greater contribution of red fruits, aromatic intensity and wood than that obtained through microwaves. Regarding the type of oak chips, Spanish oak provided more volatile compounds than French oak and with a lower proportion of undesirable aromas. At the sensory level, Spanish oak also showed greater aromatic intensity and higher values for the wood descriptor, being preferred by the panel of judges.
•Ultrasound and microwaves were applied to red wine production.•Volatile composition was influenced due to extraction techniques.•Olfactometric and sensory profiles were not modified in pre-fermentative maceration.•Wines presented betters ratings when extraction techniques were used during ageing.•Spanish oak provided wines with higher aromatic intensity than French oak.
ABSTRACT
This study reports the development and optimization of a real-time loop-mediated isothermal amplification (qLAMP) method for rapid detection of Acetobacter aceti strain in red wine samples. ...Our results showed that the primers and probes designed for 16S rRNA were effective for A. aceti detection. The quantification limit of real-time polymerase chain reaction (qPCR) and qLAMP in pure culture was 2.05 × 101 colony forming units (CFU) mL−1. qLAMP had a sensitivity of 6.88 × 101 CFU mL−1 in artificially contaminated Changyu dry red wine (CDRW) and Changyu red wine (CRW), and 6.88 × 102 CFU mL−1 in artificially contaminated Greatwall dry red wine (GDRW), which was 10 times higher than that of qPCR. In conclusion, this newly developed qLAMP is a reliable, rapid and accurate method for the detection and quantification of A. aceti species in red wine samples. Furthermore, our work provides a standard reference method for the quantitative detection of A. aceti and other acetic acid bacteria during the fermentation and storage of red wine samples.
This work involves a real-time loop-mediated isothermal amplification (qLAMP) method applied to Acetobacter aceti detection in red wine.
► Resveratrol, total phenols and antioxidant potential in wines were examined. ► Effect of thermovinification and separation of pomace on four varieties were examined. ► Resveratrol content depends ...on variety, no obvious correlation with technology. ► Thermovinification increased total phenols and antioxidant potential. ► Correlation was observed between total phenols and antioxidant potential.
In this paper, the influence of winemaking techniques and cultivars on the resveratrol content, total phenolic content and antioxidant potential of red wines was studied. Wines were made from the cultivars Merlot, Cabernet Sauvignon, Pinot Noir and Prokupac. Applied winemaking technologies included thermovinification and separation of must from pomace. The analysis of trans- and cis-resveratrol in wines was performed by HPLC, while the total phenolic content and antioxidant potential was determined by spectrophotometric methods. The total resveratrol content in analysed samples ranged from 0.35 to 4.85mg/l; Merlot wines had the highest average resveratrol content, while the lowest was found for native cultivar Prokupac. Although the resveratrol content depended on grape variety, correlation between the winemaking technology applied and the resveratrol level in wines was not observed. The total phenolic content (TPC) varied from 544.4 to 1410.4mg/l expressed as gallic acid equivalents, and the antioxidant potential, assayed by DPPH in terms of SC50 (mean scavenging concentration), ranged from 0.58 to 2.91μl/ml. Obtained results showed that thermovinificated wine samples had higher amount of phenolic compounds. Significant negative correlation was observed (p<0.05) between the total phenolic content and SC50, but there was no significant correlation (p>0.05) between the resveratrol content and SC50 or TPC. This study could contribute to the establishment of optimal conditions for producing red wines which contain more beneficial phenolic compounds.
A beverage made of red wine vinegar and grape juice (Yamanashi-no-megumi(TM)) was developed as a supplemental fluid containing polyphenols, which has been clinically shown to enhance the colonic ...transit. In this study, we assessed the mechanism of its prokinetic action by analyzing the effects on both the colonic phosphodiesterase activity of rats (n = 4) and the isolated colonic strip preparation of guinea pigs (n = 4). The 7% (v/v) solution of the beverage significantly decreased the phosphodiesterase activity by 9% (n = 4). The beverage in concentrations of 0.7, 2.1 and 7% (v/v) relaxed the colonic strips pre-contracted by 1μmol/L of carbachol in a concentration-related manner with 50, 58 and 79%, each response of which was diminished to 11, 19 and 46%, respectively in the presence of 100μmol/L of L-nitro-arginine methyl ester. These results obtained by biochemical, functional and pharmacological analyses suggest that the beverage could relax the colon through both cAMP-associated and nitric oxide-dependent pathways, which may partly explain clinically observed prokinetic effect of the beverage.
One of the main opportunities in the use of non-Saccharomyces yeasts is its great intraspecific variability in relation to the synthesis of secondary products of fermentation. Thus, mixed or ...sequential fermentation with non-Saccharomyces can increase the synthesis of certain metabolites that are important for colour stability, such as acetaldehyde and pyruvic acid (vitisin precursors) or vinylphenols (vinylphenolic pyranoanthocyanin precursors). Furthermore, the selection and use of non-Saccharomyces yeast strains with good yields in the production of certain volatile compounds (ethyl lactate, 2,3-butanediol, 2-phenylethyl acetate), with limited formation of higher alcohols, is a way to improve the aromatic profile of red wine. The main aim of this work was to evaluate the influence of sequential and mixed fermentations with Schizosaccharomyces pombe and Torulaspora delbrueckii strains on red wine's sensory quality. Anthocyanins and aromatic profiles, as well as glycerol and organic acid content, were analysed in the red wines obtained. Results show that, in general, mixed fermentations can promote an increment in polyols synthesis, while sequential fermentations can enhance the herbaceous aroma. Moreover, the use of T. delbrueckii in mixed fermentations allowed an increase to the fruity character of red wine. The use of S. pombe in sequential fermentations increased the stability of the colouring matter by favouring vitisins and vinylphenolic pyranoanthocyanin formation.
•Use of Schizosaccharomyces pombe in sequential fermentation allows increasing the contents of vitisins, especially A type.•Use of Torulaspora delbrueckii in mixed fermentation allows a potential increase of fruity aromas in the wine.•Mixed fermentations with non-Saccharomyces yeasts may increase polyol content.•3-ethoxy-1-propanol was found as a compound linked to T. delbrueckii's metabolism.•Use of S. pombe in mixed or sequential fermentations allows tempering of its characteristic high acetic acid synthesis.
•Determination ellagic acid, vanillic acid, syringic acid, quercetin, and melatonin in samples of wines.•Wine analysis of sample from Brazil, the São Francisco Valley region, and Mendoza, ...Argentina.•Geographical characterization of South America wines by chemometric tool.
This study aimed to determine ellagic acid, vanillic acid, syringic acid, quercetin, and melatonin in samples of wines from Brazil, the São Francisco Valley region, and Argentine region (Valle de Uco, Luján de Cuyo, Mendoza and Neuquén). The phenolic compounds and melatonin were determined by UHPLC MS/MS and HPLC. Quercetin was the compound found in major quantities in Argentine wines. In some bottles of Brazilian wines, vanillic acid and ellagic acid were found in higher bottles compared to Argentine wines. As for syringic acid, as selected filters in Brazilian wines, they were inferior in Argentine wines samples. PCA and HCA were carried out to group the data obtained according to the region of origin of the wines.
Tannins are responsible for the astringency of red wine where it is considered to be the perception that follows tannin interaction with salivary protein. In this study, the influence of red wine ...polysaccharides on the interactions between tannins and proteins has been investigated. The mean degree of polymerization, subunit composition and molecular mass of tannins was determined for tannins isolated from various red wines. In addition, the composition of total soluble polysaccharides was determined for polysaccharides isolated from the same red wines. The influence of polysaccharides on the interaction between tannins and protein were investigated. The ability of tannins to interact with a hydrophobic surface (tannin activity) did not significantly change after the addition of the corresponding polysaccharides. Rhamnogalacturonan II, the proportion of pigmented tannins and the mean degree of polymerization seemed to encourage protein precipitation either through the formation of insoluble tannin-polysaccharide aggregates or because of protein-polysaccharide interactions.
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•Extraction of tannins and polysaccharides from ten red wines.•Tannin activity determined by high performance liquid chromatography.•No change of tannin activity after the addition of polysaccharides to tannins.•Tannin:polysaccharide ratio (1:2) increased the concentration of tannin precipitable.•Rhamnogalacturonans II improved the tannin-protein precipitation.
This work is focused on the study of the antioxidant properties of red wine anthocyanin derivatives (carboxypyranoanthocyanins, methylpyranoanthocyanins, oxovitisins, and pyranoanthocyanin-phenolics) ...derived from malvidin-3-glucoside. Some antioxidant features were determined using the DPPH assay and the ability to delay lipid peroxidation in a liposome membrane system by monitoring oxygen consumption. The pyranoanthocyanin-phenolics have higher antioxidant potential than that of malvidin-3-glucoside, suggesting that the addition of a catechol or flavanol moiety increases the antioxidant capacity. The only derivatives that showed lower antioxidant features than malvidin-3-glucoside were oxovitisins and methylpyranomalvidin-3-glucoside. Also, the radical scavenging capacity of these pyranoanthocyanins was computationally explored using DFT methods. All pyranoanthocyanins were suggested as good candidates as antioxidant compounds because they easily donate an H atom to the free radicals, originating stable species. Altogether, these results support the fact that the antioxidant potential arising from anthocyanins is not impaired by some of their transformations during red wine aging.
