Physico-chemical characterisation of Slovak wines

Oxygen contribution to phenolic evolution during aging of red wines

Grapes and wines represent the most important source of edible stilbenes and other phenolic metabolites, which demonstrate a wide range of valuable biological activities. However, there is no information about the profile and content of phenolic compounds in Russian wines. We firstly analyzed phenolics (stilbenes, phenolic acids, and flavonols) in some representatives of Russian wines, including eleven red and seven white Russian wines from Fanagoria, Krasnodarsky Territory. The Russian red wines contained six stilbenes (trans-resveratrol, cis-resveratrol, trans-, cis-piceid, trans-piceatannol, δ-viniferin), while the white wines contained only five stilbenes (cis-resveratrol, trans-, cis-piceid, trans-piceatannol, trans-resveratrol). More than a half of the total stilbenes in the wines (65% of all stilbenes) were presented by trans-piceid and cis-piceid, while trans-resveratrol reached 16% of all the stilbenes. The red wines also contained six phenolic acids and six flavonols, while the white wines contained six phenolic acids and only three flavonols. Myrecitin-3-O-glucoside, quercetin-3-O-glucoside, and myricetin were the major flavonols in the red wines, while dihydroquercetin-3-O-rhamnoside was the major flavonol in the white wines. The red wines contained markedly higher amounts of stilbenes, phenolic acids, and flavonols than the white wines. Thus, the data showed that young red Russian Fanagoria wines represent a rich source of phenolic compounds. The study also revealed that younger wines were more abundant in phenolics, and wine storage for six months in the dark at +10 °C led to a decrease in the total content of phenolics, primarily monomeric stilbenes and quercetin-3-O-glucoside and quercetin flavonols.

Lysozyme is an enzyme with muramidase activity which can lyse Gram-positive bacteria, including wine lactic acid bacteria. This enzyme provides a practical method for delaying or preventing the growth of Oenococcus oeni and consequently the onset of malolactic fermentation during the vinification of red and white wines. This paper reports the impact of lysozyme on the chemical and sensorial properties of commercially vinified red (Cabernet Sauvignon and Shiraz) and white (Riesling) wines. The addition of lysozyme to these wines had little or no effect on the content of alcohol, free and total sulfur dioxide and titratable acidity, and pH value. The lysozyme retained 75-80% activity in the Riesling wine after six months, however no detectable activity remained in the Cabernet Sauvignon and Shiraz wines after two days. Upon addition of lysozyme to both of the red wines, a rapid initial decrease (up to 17%) in red wine colour density and phenolic content occurred in association with the formation of a light precipitate. The reduction in red wine colour was also noted by the sensory panel. When added to the Riesling wine, lysozyme did not cause an increase in browning over the six month storage time, but did induce heat instability (haze), suggesting that white wines may require protein stabilisation following treatment with lysozyme. Sensory assessment by triangle difference testing revealed that, during the six month storage period, treatment with lysozyme did not cause important changes to either the aroma or palate of the red and white wines tested.

This study examined the influence of pectinase-producing non-Saccharomyces yeasts on the chemical and sensory attributes of red and white wines with added pectin. Merlot and Chardonnay wines were produced with or without a mixture of pectinase-producing non-Saccharomyces yeasts (Cryptococcus adeliensis, Issatchenkia orientalis, and Pichia kluyveri) added to the must prior to alcoholic fermentation conducted by a commercial strain of Saccharomyces cerevisiae. To ensure sufficient substrate was present, varying concentrations of apple pectin (up to 1.25 g/L for red wines and 1.00 g/L for white wine) were added at the start of fermentation. After bottling, trained panelists (n = 10) analyzed these wines for aroma, flavor, taste, and mouthfeel attributes. For both wines, significant interactions were noted between the presence of non-Saccharomyces yeasts and pectin addition which affected pH, titratable acidity, and concentrations of D-galacturonic acid. While no significant sensory differences were observed among the red wines, limited changes were noted for white wines. However, a strong positive correlation was found between the D-galacturonic acid and buttery aroma for Chardonnay and with flavor for Merlot. Increasing D-galacturonic acid concentrations, through utilization of non-Saccharomyces yeasts, may improve the wine quality as a buttery aroma is often associated with high-quality Chardonnay. For both red and white wines, the utilization of these particular non-Saccharomyces yeasts significantly influenced chemical properties but yielded minor sensory changes without any faults. PRACTICAL APPLICATION: With the recent trend to reduce alcohol content in commercial wines, the interest in non-Saccharomyces yeasts has grown. This study showed that the addition of non-Saccharomyces yeasts, perhaps due to their pectinase activity, influenced the chemical characteristics of red and white wines with limited sensory differences, making these yeasts a useful tool for winemakers to modify wine properties.

Polyphenols synergistically inhibit oxidative stress in subjects given red and white wine

Investigation of heavy metal concentrations in some Turkish wines

Red wine polyphenols, in the absence of alcohol, reduce lipid peroxidative stress in smoking subjects

Background. Wine is one of the oldest traditional alcoholic beverages consumed worldwide. In addition, red and white wines are an excellent source of antioxidant compounds. Numerous studies have focused on the analysis of phenolic acids and flavonoids of several wines originating from organic and conventional cultivars growing grapes. However, to the authors best knowledge, there are no research papers dealing with the phenolic content of wines made on the Ionian Islands so far. Materials and methods. The amount of total phenolics, total flavonoids, total anthocyanins, total tannins, the concentrations of individual phenolic compounds, as well as the antioxidant capacity, were used synergistically to assess the compositional profile of eleven monovarietal wines. Results. As expected, red wines exhibited the strongest antioxidant profile. Vertzami was the richest variety in total phenols and antioxidant capacity, followed by the Avgoustiatis variety and Mavrodaphne variety. Regarding white wines, Thiako white had the highest total phenolic values, while Robola ros contained a similar total phenolic content as the white varieties. A highly positive correlation between the antioxidant capacity and polyphenol composition expressed as total phenolic, total flavonoid, total anthocyanin and total tannin content, was observed. Last, gallic acid and tyrosol were two of the major phenolic compounds detected in all tested wines. Conclusion. Our findings revealed that the amounts of phenolic contents and antioxidant activity vary significantly in different types of wines. The observed differences could be related to a range of variables such as geographical origin, aging, climate and the vinification techniques.

Simulation of retronasal aroma of white and red wine in a model mouth system. Investigating the influence of saliva on volatile compound concentrations

Epidemiological studies suggest that the moderate consumption of alcohol, especially red wine, protects against atherosclerosis. This hypothesis was tested using the C57BL/6 mouse atherosclerosis model. Sixty mice were fed an atherogenic diet for 15 weeks. Two groups of 20 mice received drinking water containing 3.1% alcohol, either or white wine, while the control group received plain water. At the conclusion of the experiment, serum lipoprotein cholesterol concentrations were measured and the formation of fatty streaks in the aortic sinus was quantified. When mice receiving red wine were compared with mice receiving white wine, no significant differences in serum lipoprotein profile or fatty streak formation were observed. Surprisingly, when data from mice receiving either red or white wine were combined, mice receiving alcohol developed a lower mean serum high-density lipoprotein cholesterol concentration [2.34 +/- 0.44 mmol/l (mean +/- SD)] and an increased mean area of aortic fatty streaks (0.46 +/- 0.22 mm2) than controls (2.70 +/- 0.59 mmol/l and 0.31 +/- 0.11 mm2). These results do not support the hypothesis that red wine provides more protection against atherosclerosis than white wine. The mechanisms by which the moderate intake of alcohol increased fatty streak formation in C57BL/6 mice require further investigation.

Comparative contents of some phenolics in beer, red and white wines

Effect of boiling on the total phenolic, anthocyanin and carotenoid concentrations of potato tubers from selected cultivars and introgressed breeding lines from native potato species

A new method has been developed for the quantitation of 1,8-cineole in red and white wines using headspace solid-phase microextraction (SPME) combined with stable isotope dilution analysis (SIDA) and gas chromatography-mass spectrometry (GC-MS). An extensive survey of Australian wines (44 white and 146 red) highlighted that only red wines contained significant amounts of 1,8-cineole (up to 20 μg/L). Hydrolytic studies with limonene and α-terpineol, putative precursors to 1,8-cineole, showed a very low conversion into 1,8-cineole (< 0.6%) over a 2 year period, which does not account for the difference between white and red wines. 1,8-Cineole was chemically stable in model wine solution over 2 years, and absorption from a Shiraz wine by bottle closures was most evident for a synthetic closure only (14% absorption after 1 year). Two commercial ferments at two different locations were monitored daily to investigate the evolution of 1,8-cineole throughout fermentation. Both ferments showed daily increases in 1,8-cineole concentration while in contact with grape solids, but this accumulation ceased immediately after pressing. This observation is consistent with the extraction of 1,8-cineole into the ferment from the solid portions of the grape berries.

Distribution of crown hexameric procyanidin and its tetrameric and pentameric congeners in red and white wines

Background: Moderate alcohol consumption is cardioprotective. The mechanism for this beneficial effect might be reduced inflammatory responses, as suggested by prospective studies and small clinical trials in men. No studies have evaluated the antiinflammatory effects of wine in women.Objective: We investigated whether low-dose intake of white and red wines has differential effects on inflammatory markers in women.Design: In a crossover study, we randomly assigned 35 healthy women to two 4-wk periods of 20 g ethanol/d as white or red wine, preceded by two 4-wk washout periods. Before and after interventions, we measured serum lipids, circulating inflammatory biomarkers, cellular adhesion molecules (CAMs), and adhesion of monocytes to stimulated endothelial cells.Results: HDL cholesterol increased, and the serum concentrations of high-sensitivity C-reactive protein, intercellular adhesion molecule-1, CD40L, and interleukin-6 decreased after either wine (P < 0.01, all). Vascular CAM-1 and E-selectin decreased (P < 0.01) only after red wine. CAM expression by mononuclear cells was blunted after either wine, with a greater suppressant effect of red wine. Enhanced adhesion of monocytes to stimulated endothelial cells was reduced by 51% (95% CI: −57%, −45%) after white wine and by 89% (95% CI: −96%, −82%) after red wine (P = 0.01 for between-wine differences).Conclusions: Moderate wine consumption is associated with beneficial effects on various inflammatory pathways related to endothelial activation in women. Probably because of its higher polyphenol content, red wine shows superior antiinflammatory effects than does white wine. Reducing low-grade inflammation and endothelial activation may be another potential mechanism by which alcoholic beverages exert their cardioprotective effect.