Phenolic Content Of Red Wines Research Articles

FARKLI DEPOLAMA KOŞULLARININ MERLOT ŞARAPLARINDA ANTOSİYANİN PROFİLİ ÜZERİNE ETKİSİ

Grape variety and health, soil and climate, agricultural techniques used, winemaking processes, storage time and temperature are the most important agents in the phenolic content of red wine. In this study, the effects of storage temperature and time on the distribution of anthocyanin compounds, and the total monomeric anthocyanin (TMA) content of Merlot wines were investigated at the beginning of storage and the following quarterly periods. The amount and distribution of delphinidin 3-glucoside, pelargonin 3-glucoside, malvidin 3-glucoside, cyanidin 3-glucoside, and peonidin 3-glucoside anthocyanins in wine samples were defined quantitatively by modifying HPLC method. When the change in TMA content in wines was evaluated, it was determined that there was a decrease of 13.77% at 4-5 °C, 24.28% at 8-10 °C, 43.93% at 12-14 °C, and 66.29% at 18-20 °C compared to the values before storage at the last of 24 months of storage.

Analysis of red wines using an electronic tongue and infrared spectroscopy. Correlations with phenolic content and color parameters

The objective of this work was to develop a methodology based on multiparametric methods (FTIR and a voltammetric e–tongue based on SPE) to evaluate simultaneously fourteen parameters related to the phenolic content of red wines. Eight types of Spanish red wines, elaborated with different grape varieties from different regions and with different aging, were analyzed with both systems. Input variables used for multivariate analysis were extracted from FTIR spectra and voltammograms using the kernel method. PCA analysis could discriminate wines according to their phenolic content with PC1, PC2 and PC3 explaining the 99.8% of the total variance between the samples for FTIR analysis and 85.8% for the e-tongue analysis. PLS calculations were used to establish regression models with phenolic content parameters measured by UV–Vis spectroscopy (TPI, Folin-Ciocalteu, CIELab and Glories) with high correlation coefficients (R2 > 0.85), and low RMSEs (<3.0) and number of factors (<4). Both, PCA and PLS, were carried out using the full cross validation method. As time is a critical factor in the food industry, the main advantage of these multivariate techniques is their capability to evaluate many parameters in a single experiment and in shorter time than using independent classical techniques.

Antioxidant activity, phenolic compounds and colour of red wines treated with new fining agents

Nowadays the clarification and stabilization of red wines is generally done with conventional fining agents, like bentonite and activated coal, which pose a major challenge to environmental security and wastes management. This stimulated the use of many new techniques in order to discover alternative fining agents that don’t have negative influence on color, phenolic compounds and quality parameters. The aim of this research is to determine, how alternative fining agents, in different doses, affect antioxidant activity and colour parameters of 'Cabernet Sauvignon' red wines. Experimental material is from North-East Romania and was fined with mesoporous materials, bentonite and activated coal. Discriminant analysis classified 'Cabernet Sauvignon' wines according to the different fining agents based on total polyphenolic compounds and total antioxidant activity. Alternative fining agents, as mesoporous materials, have less impact on the colour and phenolic content of red wines in contrast to activated coal and bentonite treatments that can conduct to unsatisfying characteristics. Mesoporous materials are preferable and could be an exceptional adsorbent for polyphenolic compounds.

Effect of enological tannin addition on astringency subqualities and phenolic content of red wines

AbstractFour Italian red wine varieties (Sangiovese, Montepulciano, Barbera, Nero d'Avola) were used to investigate the effect of enological tannins on astringency characteristics and phenolic content of red wines. Wines were treated with three tannins of different origins (G = grape, E= oak, and P = exotic wood) at two concentrations (10, 20 g/hl) and aged for 1 year. Wines were evaluated for astringency and for 16 subqualities using check‐all‐that‐apply questions. In addition, polymeric pigments, tannins, flavans, total anthocyanins, and color parameters were analyzed. Enological tannin promoted color stability by pigmented polymers formation. Astringency intensity was not enhanced, even better an improvement of mouthfeel sensations was achieved with wood‐derived tannins. Multivariate analysis revealed a great influence of the variety on astringency and phenolic characteristics of wines. Therefore, the initial phenolic composition of wine seems to be the main driver of the evolution of wine during aging.Practical applicationsTannin addition is an enological practice widely widespread because of many economical benefits. The use of enological tannins during aging can contribute to color stabilization and to an improvement of astringency subqualities of wines. Training on astringency subqualities with touch standards coupled with the check‐all‐that‐apply questions can provide an interesting way to reveal the different aspects of red wine astringency. Despite high astringency and high phenolic content, a wine may present desirable subqualities which can improve wine experience. Finally, a tailored use of enological tannins depends on wine variety.

Fining of Red Wines with Pomace Cell Wall Material: Effect on Wine Phenolic Composition

Fining is a winemaking technique used to remove unwanted wine components that affect clarification, astringency, color, bitterness, and aroma. One of the objectives of fining is often to reduce the wine tannin content due to its effect on wine astringency. Proteinaceous agents are commonly used with this objective, but problems related with their possible allergenic properties or the excessive enrichment of wine with proteins, which may cause stability and turbidity problems, have led to the search for new fining agents. In this way, the cell wall material from processed grape pomace could be a good alternative since it has a high affinity for tannins. In this work, the effect of cell wall material from processed pomace from Monastrell and Cabernet Sauvignon grapes on the reduction of the phenolic content of red wines is studied and the results are compared with those obtained with commercial fining products. Also, the varietal effect due to the different composition of the cell wall material from these two varieties has been evaluated. The concentration and composition of wine anthocyanins and tannins, before and after the fining process, were analyzed by HPLC and their molecular mass distribution by SEC. The results showed that, at laboratory scale, pomace cell walls have a fining effect that exceeds that of most the protein-based fining agents, even when used at their highest recommended doses. The cell wall material significantly reduced the wine phenolic content, the reduction ranging from 48 to 68% for anthocyanins and from 44 to 64% for tannins, although varietal differences exist regarding the cell wall-binding capacity. Monastrell cell walls exhibited the highest capacity and could be used at much lower doses than those used in this study, reducing the formation of lees and the wine adsorbed on them. The results indicate that this material could be an appropriate alternative for protein-based fining agents in red wine and their use would avoid allergen-related effects.

Chemical Gradients in Pilot-Scale Cabernet Sauvignon Fermentations and Their Effect on Phenolic Extraction

The phenolic content of red wine is responsible for the color and mouthfeel of the wine. Phenols are extracted from the skins and seeds of the crushed grapes through contact with the juice. Formation of a skin cap at the top of the fermentation decreases this contact, necessitating cap management techniques such as punch-downs or pump-overs. While it is clear that these techniques are necessary for extraction, the kinetics of phenolic release, adsorption, and reaction in this heterogeneous system are not well understood. To better understand these kinetics, pilot-scale (2000 L) Cabernet Sauvignon fermentations were performed in two consecutive harvests (2011 and 2012) using a tank modified with a custom sampling array that allowed sampling of the fermentations at four depths (two in the cap and two in the liquid), with three replicate sampling points at each depth. Chemical gradients were observed for several phenolics, including gallic acid, (+)-catechin, (−)-epicatechin, caftaric acid, malvidin-3-O-glucoside, total anthocyanins, and condensed tannins. Chemical gradients for skin phenolics, such as the anthocyanins, were observed to develop early during fermentation and to diminish as fermentation progressed. Phenolics found primarily within the seed, such as (+)-catechin, exhibited chemical gradients throughout the fermentation. Seed extraction trends were confirmed with phloroglucinolysis. Interestingly, the phenolic gradients were eliminated following a pump-over event, but were re-established during the subsequent few hours and approached a saturation point ~8 hrs after the pump-over for skin phenolics, while saturation behavior was not as pronounced for the seed phenolics.

Effects of Cap and Overall Fermentation Temperature on Phenolic Extraction in Cabernet Sauvignon Fermentations

The phenolic content of red wine is responsible for the color, mouthfeel, and aging potential of the wine. Although many fermentation parameters and winemaking techniques affect phenolic extraction, it is generally agreed that one of the prime factors is fermentation temperature; however, temperature is not uniform during fermentation and thermal gradients form between the cap and the liquid. To determine the effects of temperature on phenolic extraction, research scale (120 L) Cabernet Sauvignon fermentations were performed in which the cap and must were either maintained at the same temperature or a constant thermal gradient was maintained between the two during the period of active fermentation. All fermentations were sampled twice daily and phenolic content was determined by reverse-phase high-performance liquid chromatography for the monomeric phenolics and UV-vis spectroscopy for the total anthocyanins and condensed tannins. These experiments showed that cap and must temperature had noticeable effects on phenolic extraction based on where the phenolics originated. For skin phenolics, temperature affected the rate of extraction but not the final concentration, and increasing temperatures favored faster extraction. For seed phenolics, increases in fermentation temperature increased both the rate of extraction and the final concentration. Results showed that must temperature was more important than cap temperature in driving extraction of phenolics.

De-alcoholised white and red wines decrease inflammatory markers and NF-κB in atheroma plaques in apoE-deficient mice

Wine polyphenols attenuate the development of atherosclerosis, which involves an inflammatory process. We studied the beneficial effect of de-alcoholised white and red wines (DWW and DRW, respectively) on the development of atheroma plaques and on the expression of biomarkers. We administered control or de-alcoholised wine-rich diets to apoE-deficient mice for 12 or 20 weeks. We then used optical microscopy or immunofluorescence to examine atherosclerotic lesion development in the thoracic aorta and aortic root and assessed the presence of cytokines and adhesion molecules by qPCR and immunofluorescence in total aorta and aortic root, respectively. Atherosclerotic lesions in thoracic aorta were significantly decreased in mice supplemented with DWW (30 %) and DRW (62 %) for 20 weeks. In addition, the expressions of interferon-γ, interleukin-1β, the monocyte chemoattractant protein-1 and CD68 were reduced by DRW. The adhesion molecule P-selectin, vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 were decreased by 52, 76 and 45 %, respectively, in mice fed DRW for 12 weeks, whereas DWW reduced these parameters in a minor extent. The NF-κB expression in total aorta was significantly decreased in the mice treated with de-alcoholised wines for 12 weeks. DRW is shown to be more effective than DWW on cytokines and adhesion molecule expression, in the early stages of the inflammatory events associated with atherosclerosis development, probably due to the high phenolic content of red wine. Downregulation of NF-κB expression may be involved in the mechanism by which de-alcoholised wines modulate atherosclerosis.

Differential effects of polyphenols and alcohol of red wine on the expression of adhesion molecules and inflammatory cytokines related to atherosclerosis: a randomized clinical trial

Few clinical studies have focused on the alcohol-independent cardiovascular effects of the phenolic compounds of red wine (RW). We aimed to evaluate the effects of ethanol and phenolic compounds of RW on the expression of inflammatory biomarkers related to atherosclerosis in subjects at high risk of cardiovascular disease. Sixty-seven high-risk, male volunteers were included in a randomized, crossover consumption trial. After a washout period, all subjects received RW (30 g alcohol/d), the equivalent amount of dealcoholized red wine (DRW), or gin (30 g alcohol/d) for 4 wk. Before and after each intervention period, 7 cellular and 18 serum inflammatory biomarkers were evaluated. Alcohol increased IL-10 and decreased macrophage-derived chemokine concentrations, whereas the phenolic compounds of RW decreased serum concentrations of intercellular adhesion molecule-1, E-selectin, and IL-6 and inhibited the expression of lymphocyte function-associated antigen 1 in T lymphocytes and macrophage-1 receptor, Sialil-Lewis X, and C-C chemokine receptor type 2 expression in monocytes. Both ethanol and phenolic compounds of RW downregulated serum concentrations of CD40 antigen, CD40 ligand, IL-16, monocyte chemotactic protein-1, and vascular cell adhesion molecule-1. The results suggest that the phenolic content of RW may modulate leukocyte adhesion molecules, whereas both ethanol and polyphenols of RW may modulate soluble inflammatory mediators in high-risk patients. The trial was registered in the International Standard Randomized Controlled Trial Number Register at http://www.isrctn.org/ as ISRCTN88720134.

Changes in the color components and phenolic content of red wines from Vitis vinifera L. Cv. “Tempranillo” during vinification and aging

Changes in phenolics and color components during vinification and aging of Tempranillo wines were studied. Different phenolics display different diffusion into the must, and with the exception of proanthocyanidins and acetyl-glucoside anthocyanins, with maximum concentration at the end of postmaceration, the rest of the unacylated and coumarated anthocyanins, monomeric flavanols, and hydroxycinnamic acids reached their maximum at the end of alcoholic fermentation. This resulted in a significant increase in both wine color and stable color, mainly due to the formation of copigmentation complexes, although polymeric pigment formation was also important. Malolactic fermentation produced a significant decrease in flavonoid content while nonflavonoid concentrations were maintained, prompting a considerable loss in wine color, despite the dramatic increase in bisulfite-stable color. Wine oak aging did not produce any significant change in the studied parameters, while bottle aging reduced the level of monomeric anthocyanins and flavanols, and hydroxycinnamic acids. However, wine color remained stable due to a significant increase in stable color. Polymerization reactions of anthocyanins prevailed over pigment degradation reactions, and copigmentation was still relevant after 2 years of bottle aging.

Trans-resveratrol and Other Phenolic Compounds in Turkish Red Wines with HPLC

The moderate consumption of red wine has a relatively great benefit in the prevention of atherosclerosis and coronary heart disease (CDH). Resveratrol, quercetin, and other polyphenolic flavonoids constitute the phenol content of wine, which have also been reported to be cancer preventive agents. The grape varieties, climate, soil, the use of agronomic techniques, the health of grapes and wine making processes are the most important factors on the phenolic content of red wine. In this research, direct injection high-performance liquid chromatography (HPLC) is applied for the determination of trans-resveratrol and some phenolic antioxidants (catechin, epicatechin, quercetin and rutin) in sample wines. The wines are mostly known traditional Turkish red wines produced from different grape varieties originated from different geographical regions.

Evolution of the phenolic content of red wines from Vitis vinifera L. during ageing in bottle

The evolution of the phenolic content, as measured by spectrophotometric methodologies [total polyphenols (TP), low-polymerized polyphenols (LPP), total anthocyanins (TA), catechins (CAT), proanthocyanidins (PRO) and o-diphenols (OD)], was studied in young red wines from Vitis vinifera L. cv Tempranillo, Graciano and Cabernet Sauvignon during 26 months of ageing in bottle. Although the wines showed differences in their initial phenolic profiles, the evolution trend of the different families of phenolic compounds was similar in the wines from the three grape varieties. TA markedly decreased during ageing in bottle (43% for Tempranillo, 65% for Graciano and 66% for Cabernet Sauvignon), following a first-order kinetic. Calculation of the kinetic parameters revealed that the disappearance rate of TA was 2-fold lower for Tempranillo wine than for Graciano and Cabernet Sauvignon wines, which exhibited similar kinetics. This decrease in TA (due to the disappearance of monomeric anthocyanins), together with a increase registered in CAT and PRO (due to the cleavage of proanthocyanidins and their structural tranformations), was consistent with a decrease in LPP, suggesting the occurrence of condensation reactions during ageing in bottle. The evolution trends observed for TP and OD during ageing in bottle were the results of changes in the different groups of phenolic compounds involved in both determinations. Global phenolic determinations, usually performed in wineries, provided useful information in relation to the evolution of wine polyphenols during ageing in bottle.

Relationship among antioxidant activity, vasodilation capacity, and phenolic content of red wines.

The relationship among antioxidant activity, based on the electron-spin resonance determination of the reduction of Fremy's radical, vasodilation activity, and phenolic content was investigated in 16 red wines. The wines were selected to provide a range of origins, grape varieties, and vinification methods. Sensitive and selective HPLC methods were used for the analysis of the major phenolics in red wine: free and conjugated myricetin, quercetin, kaempferol, and isorhamnetin; (+)-catechin, (-)-epicatechin, gallic acid, p-coumaric acid, caffeic acid, caftaric acid, trans-resveratrol, cis-resveratrol, and trans-resveratrol glucoside. Total anthocyanins were measured using a colorimetric assay. The total phenolic content of the wines was determined according to the Folin-Ciocalteu colorimetric assay and also by the cumulative measurements obtained by HPLC. The 16 wines exhibited a wide range in the values of all parameters investigated. However, the total phenol contents, measured both by HPLC and colorimetrically, correlated very strongly with the antioxidant activity and vasodilation activity. In addition, the antioxidant activity was associated with gallic acid, total resveratrol, and total catechin. In contrast, only the total anthocyanins were correlated with vasodilation activity. The results demonstrate that the different phenolic profiles of wines can produce varying antioxidant and vasodilatant activities, which opens up the possibility that some red wines may provide enhanced health benefits for the consumer.