Red Wine Anthocyanins Research Articles

Red Wine Inspired Chemistry: Hemisynthesis of Procyanidin Analogs and Determination of Their Protein Precipitation Capacity, Octanol-Water Partition, and Stability in Phosphate-Buffered Saline.

Ten dimeric procyanidin (PC) analogs were hemisynthesized from catechin or epicatechin and from five different aldehydes using the same mechanism that produces the important acetaldehyde-mediated adducts of proanthocyanidins (PAs) and anthocyanins in red wine. Protein precipitation capacity (PPC), octanol-water partition coefficient (log P) and stability of the PC analogs were determined. The emphasis was on the PPC because it has been shown to correlate with anthelmintic activity against gastrointestinal nematodes in ruminants and with other beneficial bioactivities in animals, as well. The PPC of PC analogs was greatly improved compared to natural PC dimers, but the capacity was not as great as that of a PC trimer or epigallocatechin gallate. The log P of PC analogs varied from hydrophobic to hydrophilic depending on the intramolecular linkage. Great variation was observed in stabilities of PC analogs in phosphate buffered saline, and the mixtures of degradation products were characterized using high-resolution mass spectrometry.

Rapid determination of free sulfur dioxide in wine and cider by capillary electrophoresis

A novel method for the determination of “true” free sulfur dioxide (SO2) in wine and cider was developed using capillary electrophoresis with direct ultraviolet-visible spectrophotometric detection (CE-UV/vis). Free SO2 was measured in model solutions with different SO2-binding agents present (α-ketoglutarate, pyruvate, acetaldehyde, glucose, fructose, and malvidin-3-glucoside) as well as a variety of white and red wines and ciders. The CE method was compared to three conventional methods for measuring free SO2, the Ripper method, Aeration-Oxidation (AO), and pararosaniline by discrete analyzer (DA). While some statistically significant differences (p<0.05) were found between the four methods in unpigmented model solutions and samples, the values generally agreed. In the presence of anthocyanins in model solution and red wines, free SO2 values found by CE were significantly lower than the other three methods (p<0.05). The difference in values found by Ripper and CE correlated strongly with anthocyanin content (R2 = 0.8854) and even more strongly when accounting for polymeric pigments (R2 = 0.9251). The results in red ciders differed from those in red wines, while the CE measured significantly lower free SO2 values than the other three methods, the difference in free SO2 values measured by CE and Ripper correlated more closely with anthocyanin concentration (R2 = 0.8802) than absorbance due to bleachable pigment (R2 = 0.7770). The CE method was found to be rapid (4 min/injection), sensitive (LOD=0.5 mg/L, LOQ=1.6 mg/L free SO2 in wine, 0.8 and 2.8 mg/L, respectively, in cider), robust, and repeatable (average RSD = 4.9%) and did not suffer from the issue of over-reporting free SO2 in pigmented samples often observed with currently accepted methods.

Study of the Effect of Antibiotics in Drinking Water on the Content of Antioxidant Compounds in Red Wines

The presence of antibiotic residues in drinking water may be a source of contamination, which could affect the diffusion of polyphenols into the wine must during the traditional fermentation process. Antibiotic residues such as ivermectin, hydroxychloroquine, ciprofloxacin, and azithromycin on the diffusion of polyphenols and anthocyanins during wine fermentation were studied. Different samples were taken at different periods (0, 48, 96, and 168 h) to analyse the total polyphenols, anthocyanin content, and antioxidant capacity, which were correlated with Peleg's equation to establish the diffusion kinetics of these compounds. The results indicated that the presence of antibiotics reduced between 40 and 50% the diffusion of the total polyphenols and monomeric anthocyanins in red wine. The use of ivermectin showed the highest kinetic parameter k1 compared with the use of other antibiotics. This suggested that the chemical structure and molecular weight of the antibiotics could play an important role in inhibiting the metabolism of yeasts affecting the ethanol and CO2 production. Consequently, cell membranes would be impermeable and would not allow the release of polyphenols and anthocyanins. Therefore, it is necessary to establish strategies that allow future water quality control in wine production companies.

SCREENING OF CONTAINS OF ANTIOXIDANTS IN TRADITIONAL WINES OF THE TRANSCARPATHIAN REGION

Antioxidants play an important role in human health by performing various functions, including anticancer. Among antioxidants, the most common are polyphenols, including anthocyanins, the main sources, of which are berries and fruits. Red grape wines are a potentially important source of antioxidants, and red wine polyphenols have anticancer and antioxidant effects and have a positive effect on blood red blood cells. This is obviously related to the so-called "French paradox" of wine, because the regular consumption of dry red wine by the French dramatically reduces the incidence of cardiovascular disease and cancer.&#x0D; Transcarpathia has long traditions of grape wines production, known aboard of the country. This was facilitated by special climatic conditions, soil factors of the grape provinces of Transcarpathia and the skill of the winemakers. In this work we report, a high total content of polyphenolic compounds and anthocyanins in red wines derived from European grape varieties based on the screening of antioxidant content in traditional wines of Transcarpathia. Wines from grapes of the hybrid variety "Isabella" and European varieties "Merlot" and "Cabernet Sauvignon" were studied in three main wine-growing regions of the region. Among the studied red wines (harvested in 2020), the highest total content of polyphenolic compounds is observed in wine from Merlot grapes (2.75 g´L-1), which was obtained in Berehove district. In the same wine, there is the highest total content of anthocyanins (0.715 g´L-1, is 26% of the gross content of polyphenols). Such wine can have a high anti-cancer effect, and its consumption in moderate amounts will have a preventive effect on human health. At the same time, it is shown that the antioxidant properties of red grape wines persist for a short time after uncorking the bottles.

Reactivity comparison of three malvidin-type anthocyanins forming derived pigments in model wine solutions

Malvidin-3-O-glucoside (MvG), malvidin-3-O-(6-O-acetyl)-glucoside (MvAG), and malvidin-3,5-O-diglucoside (MvDG) are three representative malvidin-type anthocyanins in red wine. In this study, the influence of structural differences on the formation efficiency of two types of derived pigments ((−)-epicatechin-ethyl-anthocyanins and pyranoanthocyanins) was investigated in model solutions using UHPLC-MS. The results showed that the yields of MvAG were higher than those of MvG to form both types of derived pigments, and the formation rate of pyranoanthocyanin was also relatively higher. In contrast, acetylation slowed the formation of (−)-epicatechin-ethyl-anthocyanins, indicating that the rate of covalent reactions may be linked to the affinity of (−)-epicatechin to copigment with anthocyanins. The condensation rate of MvDG with (−)-epicatechin, mediated by acetaldehyde, was much lower than that of the two monoglucosidic anthocyanins and also exhibited lower yields. In addition, pyranoanthocyanin was not generated from MvDG due to the absence of a free hydroxyl group at the C5 position.

A new cyanine from oxidative coupling of chlorogenic acid with tryptophan: Assessment of the potential as red dye for food coloring

A red pigment was prepared by reaction of chlorogenic acid (CGA) with tryptophan (TRP) in air at pH 9 (37% w/w yield) and evaluated as food dye. The main component of pigment was formulated as an unusual benzochromeno[2,3-b]indole linked to a TRP unit, featuring a cyanine type chromophore (λmax 542, 546 nm, 1% extinction coefficient of the sodium salt = 244 ± 2). The chromophore showed a minimal pH dependence and proved stable for at least 3 h at 90 °C, both at pH 3.6 or 7.0, whereas red wine anthocyanins showed a substantial (30%) and betanin a complete abatement after 1 h at the acidic pHs. An intense coloring of different food matrices was obtained with the pigment at 0.01 % w/w. No toxicity was observed up to 0.2 mg/mL on hepatic and colonic cell lines. These data make this dye a promising alternative for red coloring of food.

Can a Corn-Derived Biosurfactant Improve Colour Traits of Wine? First Insight on Its Application during Winegrape Skin Maceration versus Oenological Tannins.

In winemaking, oenological tannins are used to preserve wine colour by enhancing the antioxidant activity, taking part in copigmentation, and forming polymeric pigments with anthocyanins. As a novel processing aid, in this study, a biosurfactant extract was evaluated as a solubilizing and stabilizing agent of anthocyanins in red wine. The biosurfactant extract under evaluation was obtained from a fermented residual stream of the corn milling industry named corn steep liquor (CSL). Two red winegrape varieties (Vitis vinifera L. cv. Aglianico and Cabernet sauvignon) were studied for anthocyanin content and profile, and colour traits, during simulated skin maceration for 7 days at 25 °C, as well as polymerization and copigmentation at the end of maceration. A model wine solution was used as a control, which was added either with the CSL biosurfactant or with four different oenological tannins (from grape skin, grape seed, quebracho, and acacia). The results showed that CSL biosurfactant addition improved the colour properties of skin extracts by the formation of more stable compounds mainly through copigmentation interactions. These preliminary results highlighted that the effectiveness of CSL biosurfactant is variety-dependent; however, there is no significant protection of individual anthocyanin compounds as observed for delphinidin and petunidin forms using quebracho tannin.

Inactivation of &lt;i&gt;Brettanomyces bruxellensis&lt;i&gt; and &lt;i&gt;Saccharomyces cerevisiae&lt;i&gt; in dry and sweet wines by high hydrostatic pressure

The aim of the research was to investigate a potential application of high hydrostatic pressure (HHP) for reduction/elimination of Brettanomyces bruxellensis and Saccharomyces cerevisiae in wines. Dry red wine was inoculated with B. bruxellensis and sweet white wine was inoculated with S. cerevisiae yeast. Both wines were treated by HHP under 100 and 200 MPa for 1, 3, 5, 15 and 25 min. The culturability was determined immediately after the treatment and again after 30, 60 and 90 days of storage. The phenolic content and chromatic characteristics were evaluated spectrophotometrically immediately after the treatment and after 90 days of storage. The culturability of B. bruxellensis was not confirmed immediately after the most invasive treatment (200 MPa for 15 and 25 min). With the same parameters, only a decrease in the culturability of S. cerevisiae was observed. During storage, opposing results were observed for two yeasts treated with 200 MPa for 15 and 25 min: there was a complete reduction of S. cerevisiae in the wine treated, but the culturability of B. bruxellensis completely recovered in all wines, implying that B. bruxellensis yeast entered a viable but not culturable (VBNC) state after HHP exposure. Regarding the chemical analyses, applied process parameters induced a slight decrease of anthocyanins in red wine, while changes of total phenolics and total colour difference value were negligible. In conclusion, HHP could potentially be successful for microbial stabilisation of sweet wines and consequently assure a lower use of sulphur dioxide, while inactivation of B. bruxellensis could only be successful in the early stages of wine contamination.

In vitro gastrointestinal absorption of red wine anthocyanins – Impact of structural complexity and phase II metabolization

Malvidin-3-O-glucoside, malvidin-3,5-O-diglucoside, malvidin-3-O-(6-O-coumaroyl)-glucoside-5-O-glucoside from Chinese Vitis davidii red wine were used to investigate the role of glucoside, diglucoside and coumaroylated glucoside moieties on their transport efficiency through MKN-28 gastric and Caco-2 intestinal cells. Due to the already described conversion of 3-O-glucosylated anthocyanins into 3-O-glucuronidated, the 3-O-glucuronidated metabolite of malvidin-3-O-glucoside was also tested. The antiproliferative activity was higher for the glucuronidated metabolite in both cell lines. All anthocyanins were transported through MKN-28 gastric cells and Caco-2 intestinal cells with transport efficiencies ranging from 4% to 9% in MKN-28 and from 3% to 5% in Caco-2. No significant differences on transport efficiencies were observed at 180 min among the different anthocyanins in MKN-28. The transport efficiency of malvidin-3-O-glucuronide at 180 min was about 3–4% in Caco-2 and MKN-28 cells. Computational studies were performed to evaluate the interaction between anthocyanins and glucose gastric transporters GLUT1 and GLUT3, which supported the experimental findings.

Potential of Cooperage Byproducts Rich in Ellagitannins to Improve the Antioxidant Activity and Color Expression of Red Wine Anthocyanins.

Cooperage byproducts are an important source of phenolic compounds that could be used for wine technology applications. The effects of the addition of two types of oak wood shavings (American, AOW, and Ukrainian, UOW) on the antioxidant activity and color of red wine anthocyanins, in a wine model solution, were evaluated by spectrophotometric and colorimetric analyses. Phenolic compounds from shavings, mainly ellagitannins, were determined by ultra-high-performance liquid chromatography/mass spectrometry (UHPLC/MS). Antioxidant and copigmentation effects varied depending on the type of shavings (AOW and UOW) and the phenolic concentration (100, 400, and 500 mg/L). Phenolic compounds from shavings improved the color characteristics (darker and more bluish color) and the copigmentation effect of red wine anthocyanins, being UOW a better source of copigments than AOW shavings. The best antioxidant activity was found for the 400 and 500 mg/L model solutions for both types of shavings. Results show a winemaking technological application based on the repurposing of cooperage byproducts, which could improve color and antioxidant characteristics of red wines.

Research of anthocyanins in red special wine "Nikala"

Research of anthocyanins in red special wine "Nikala"

Comparison of the in vitro gastrointestinal bioavailability of acylated and non-acylated anthocyanins: Purple-fleshed sweet potato vs red wine

Acylated anthocyanins from purple-fleshed sweet potato (PFSP) have been reported to have multiple benefits to human health. Although, the bioavailability of these anthocyanins remains unknown. In the present study, a characterization of the gastrointestinal bioavailability of PFSP anthocyanins was assayed and compared with the bioavailability of Red Wine anthocyanins. Acylated anthocyanins showed higher resistance to overall simulated digestions when compared to less complex anthocyanins from Red wine, with degradation at the intestinal level of about 30% and 45%, respectively. Transport rates of absorption of acylated anthocyanins were not dependent on the cell type. However, a higher transport efficiency was observed in gastric cells (8%) when compared to the intestinal cells (5%). Glucose and proteins, but not starch, decreased the transport efficiency of anthocyanins in about 3–7% in gastric cells and 2–3% in intestinal cells. These results bring new insights and lay the groundwork for further research on acylated anthocyanins bioavailability.

Rapid Quantification of Four Anthocyanins in Red Grape Wine by Hydrophilic Interaction Liquid Chromatography/Triple Quadrupole Linear Ion Trap Mass Spectrometry.

The identification and quantification of four anthocyanins (cyanidin-3-O-glucoside, peonidin-3-O-glucoside, delphinidin-3-O-glucoside, and malvidin-3-O-glucoside) in red grape wine were carried out by hydrophilic interaction liquid chromatography/triple quadrupole linear ion trap MS (HILIC/QTrap-MS/MS). Samples were diluted directly and separated on a Merck ZIC HILIC column with 20 mM ammonium acetate solution-acetonitrile mobile phase. Quantitative data acquisition was carried out in the multiple reaction monitoring mode. Additional identification and confirmation of target compounds were performed using the enhanced product ion mode of the linear ion trap. The LOQs were in the range 0.05-1.0 ng/mL. The average recoveries were in the range 94.6 to 104.5%. The HILIC/QTrap-MS/MS platform offers the best sensitivity and specificity for characterization and quantitative determination of the four anthocyanins in red grape wines and fulfills the quality criteria for routine laboratory application.

Experimental and Theoretical Data on the Mechanism by Which Red Wine Anthocyanins Are Transported through a Human MKN-28 Gastric Cell Model.

The gastric absorption of red wine anthocyanins was evaluated using a gastric MKN-28 cell barrier model. Anthocyanin transport was not affected by the presence of 4% ethanol and decreased with the increase of pH. Gastric cells pretreated with anthocyanins were found to increase anthocyanin transport. The presence of d-(+)-glucose was found to decrease anthocyanin uptake, suggesting the involvement of glucose transporters. RT-PCR assays revealed that GLUT1, GLUT3, and MCT1 transporters were expressed in MKN-28 cells. Computational studies were performed to provide a structural characterization of the binding site of hGLUT1 to glucose or different anthocyanins under different forms. Docking results demonstrated that anthocyanins can bind to glucose transporters from both intracellular and extracellular sides. Anthocyanins seem to enter into the transporter by two main conformations: B ring or glucose. From MD simulations, hGLUT1 was found to form complexes with all anthocyanins tested in the different protonation states.

Bioconversion of Pinot noir anthocyanins into bioactive phenolic compounds by lactic acid bacteria

There has been increasing interest in red wine anthocyanins in relation to changes brought about by lactic acid bacteria in the human digestive system. Anthocyanins are modified multiple times prior to being absorbed, so that intact anthocyanins are unlikely to survive the process, although the parent compounds may still act as local antioxidants within the digestive system. Metabolites such as phenolic acids are easier to absorb, and are thus more bioavailable. This study has investigated the biotransformation of the representative Pinot noir anthocyanin, malvidin-3-glucoside, into metabolites by Lactobacillus plantarum at pH 3.4, 4.2, 5.9 and 7.0 incubated anaerobically at 37 ◦ C for up to 24 hours. The metabolites were identified by HPLC-MS. Anthocyanin glycosides were found to be completely hydrolyzed by all selected strains at pH 5.9 after 24 h of incubation. The anthocyanins were quite stable under acidic conditions (pH 3.4) but were highly unstable at neutral pH due to both chemical and microbial degradation. The main metabolites were phenolic acids such as gallic acid and protocatechuic acid. They showed greater antioxidant activity than the parent anthocyanins, as indicated by radical scavenging assays and through an assessment of reducing strength using cyclic voltammetry.

Characterization of Selected Organic and Mineral Components of Qvevri Wines

The organic and mineral components of 20 qvevri wines from selected wineries throughout Europe were evaluated to gain insight into one of the oldest known methods of wine production. The pH, residual glucose, titratable acidity, specific organic acids (acetic, lactic, malic, and tartaric acids), phenolics (total phenolics and anthocyanins in red wines), total antioxidants, and selected minerals (phosphorus, calcium, magnesium, manganese, potassium and zinc) of the samples were measured. The data were compared with previously reported values for conventional wines. Qvevri wines were less acidic than conventional wines, containing higher levels of acetic and lactic acids but lower levels of tartaric acid. They also contained higher levels of antioxidants and total phenolics, the latter up to 10 times more abundant in the white wine varieties than in conventional wines. Despite fermentation in clay vessels, the mineral content of qvevri wines was within the normal reported range, although phosphorus levels were slightly higher. This is the only study that has considered the compositional nature of qvevri wines.

Advanced ultra high pressure liquid chromatography–tandem mass spectrometric methods for the screening of red wine anthocyanins and derived pigments

Anthocyanins are responsible for the colour of red grapes and wine. In addition to their contribution to the sensory properties of wine, these compounds are also of interest due to their beneficial biological properties. Wine anthocyanins exhibit a large structural diversity due to variations in glycosylation and acylation patterns, which is further exacerbated by the diverse reactions involving grape-derived anthocyanins during wine ageing. Chromatographic as well as mass spectrometric resolution of wine anthocyanins is often precluded due to the complexity of these compounds. In this paper we report a rapid, high-efficiency ultra high pressure liquid chromatography (UHPLC) procedure with tandem mass spectrometric (MS/MS) detection for the in-depth screening of wine pigments. Selective detection of wine anthocyanins and derived pigments was achieved utilizing MS/MS in neutral loss scanning mode to observe the loss of dehydrated sugar moieties. This facilitated tentative compound identification based on molar mass information as well as the structured elution order of these compounds. In a second experiment, product ion spectra were recorded to allow identification of the anthocyanidin base using characteristic fragmentation patterns. The proposed methodology therefore involves two analyses for the sensitive and accurate identification of anthocyanins and their derived products in red wines. Mass spectra of wine anthocyanins under high energy collision induced dissociation (CID) conditions are reported, some for the first time. Significantly, chemical alteration of anthocyanins during wine ageing results in an off-set of the predominant fragments for each anthocyanidin base, whilst maintaining similar relative intensities. This allows unambiguous assignment of the derived products of anthocyanidin-glycosides. Using this approach, a total of 121 anthocyanins and derived compounds were identified in wines based on their relative reversed phase elution order as well as mass spectral information.

Anthocyanins and Their Variation in Red Wines I. Monomeric Anthocyanins and Their Color Expression

Originating in the grapes, monomeric anthocyanins in young red wines contribute the majority of color and the supposed beneficial health effects related to their consumption, and as such they are recognized as one of the most important groups of phenolic metabolites in red wines. In recent years, our increasing knowledge of the chemical complexity of the monomeric anthocyanins, their stability, together with the phenomena such as self-association and copigmentation that can stabilize and enhance their color has helped to explain their color representation in red wine making and aging. A series of new enological practices were developed to improve the anthocyanin extraction, as well as their color expression and maintenance. This paper summarizes the most recent advances in the studies of the monomeric anthocyanins in red wines, emphasizing their origin, occurrence, color enhancing effects, their degradation and the effect of various enological practices on them.

High-efficiency high performance liquid chromatographic analysis of red wine anthocyanins

The analysis of anthocyanins in natural products is of significant relevance in recent times due to the recognised health benefits associated with their consumption. In red grapes and wines in particular, anthocyanins are known to contribute important properties to the sensory (colour and taste), anti-oxidant- and ageing characteristics. However, the detailed investigation of the alteration of these compounds during wine ageing is hampered by the challenges associated with the separation of grape-derived anthocyanins and their derived products. High performance liquid chromatography (HPLC) is primarily used for this purpose, often in combination with mass spectrometric (MS) detection, although conventional HPLC methods provide incomplete resolution. We have previously demonstrated how on-column inter-conversion reactions are responsible for poor chromatographic efficiency in the HPLC analysis of anthocyanins, and how an increase in temperature and decrease in particle size may improve the chromatographic performance. In the current contribution an experimental configuration for the high efficiency analysis of anthocyanins is derived using the kinetic plot method (KPM). Further, it is shown how analysis under optimal conditions, in combination with MS detection, delivers much improved separation and identification of red wine anthocyanins and their derived products. This improved analytical performance holds promise for the in-depth investigation of these influential compounds in wine during ageing.

Anthocyanin composition in aged Chilean Cabernet Sauvignon red wines

Anthocyanins in aged Cabernet Sauvignon red wines were studied by HPLC–MS. The major anthocyanin in 6, 7, and 8year old red wine extracts was the dimer vitisin A produced by condensation of malvidin-3-O-glucoside mediated by pyruvic acid. In aged wine, the content of malvidin-3-O-glucoside decreased with age with a concomitant increase of vitisin A. The latter is accompanied by several condensation products with molecular weight up to 1500m/z. Differential pulse voltammetry indicated that aged wines have lower antioxidant capacity than young wine (400mV), but higher than malvidin-3-O-glucoside (483mV). Tafel’s plots showed that the electrochemical process occurring in aged wines is different from young wines. Six, seven and eight year old wines show similar behaviour with plots of 234, 177 and 188mV/dec, respectively. These values are higher than the expected 120mV/dec corresponding to a first electronic transfer but smaller compared to the 523mV/dec corresponding to young wine.