Influence of variety and commercial yeast preparation on red wine made from autochthonous Hungarian and Canadian grapes. Part I: phenolic composition

Eight wines were made from two Canadian hybrid grape varieties (Maréchal Foch, Baco Noir) and two Hungarian Vitis vinifera varieties (Kadarka, Lemberger). One half was kept untreated; the other half received a commercial yeast preparation (OptiRed^®) before fermentation. Significant differences were found between varieties for basic measures of wine quality, including pH, titratable acidity, ethanol, colour density, hue and total phenolics. Quercetin was identified only in Maréchal Foch and Baco Noir wines, and quercetin-glucoside only in Baco Noir. Varietal differences were also found in the concentrations of the 11 other colourless phenolic monomers measured, especially gallic acid, protocatechuic acid, tyrosol, caftaric acid, catechin, caffeic acid, GRP, epicatechin, p-coumaric acid, ferulic acid and trans-resveratrol. The Canadian wines had higher concentrations of the four anthocyanins measured (malvidin, delphinidin, petunidin and peonidin), higher anti-oxidative capacity, and were characterised by lower ratios of monomeric/polymeric phenolics. Addition of OptiRed^® had little impact on the basic measures of wine quality. Concentrations of gallic acid, protocatechuic acid, caftaric acid and catechin were, on average, 6% higher in wines made from OptiRed^®-treated musts. A trend was observed for all varieties in OptiRed^®-treated wines of a greater proportion of the procyanidins being presented as polymeric rather than monomeric phenolics.     

Nutraceutical value and toxicological profile of selected red wines from Morocco

The polyphenolic composition, antioxidant properties and multielement profile of selected red wines from Morocco were evaluated. The polyphenolic contents resulted higher than those reported elsewhere for the same variety of wines; the highest quantity was found in Cabernet Sauvignon, followed by Merlot, and last by Syrah wine. All of the wines tested showed very similar anthocyanin and flavonol patterns: individual compound contents resulted generally higher in comparison to conventional wines. The content of trans-resveratrol was significantly higher than that of cis-resveratrol in all of the wine samples. Particularly, Merlot showed the highest concentration of trans-resveratrol while Syrah exhibited the highest levels of cis-resveratrol. Reducing capacity resulted higher than antiradical property for all of the wines. The metal concentrations were below the official limits. The elemental pattern of wines were very similar, excepted V, Mn, Fe, Cu, As and Mo, for which Syrah markedly differed from the other wine samples.     

Impact of Pressing Conditions on the Phenolic Composition,Radical Scavenging Activity and Glutathione Content of Brazilian <Emphasis Type="Italic">Vitis vinifera</Emphasis> White Wines and Evolution During Bottle Ageing

The pre-fermentation techniques applied during the production of white wine, such as skin maceration or grape pressing, can directly affect the quality of the final product. There is a constant search for methods that can enhance the sensorial characteristics, such as varietal aromas, and phenolic composition of white wines. The aim of this study was to investigate the effect of different pressing conditions on the phenolic composition, antioxidant activity and glutathione content of white musts and wines produced in southern Brazil and to evaluate these characteristics during bottle ageing. By applying different pressures, three fractions of musts were obtained: free-run must, light pressed must and heavy pressed must. The musts and their corresponding wines were analysed by spectrophotometric and chromatographic assays. Pressing positively affected the chemical composition of the musts and wines, and the wines produced with pressed fractions of the musts presented higher polyphenol content and radical scavenging power. The main phenolic compounds affected by the pressing conditions were caftaric acid, catechin and epicatechin. During bottle ageing, an increase in certain individual phenolic compounds could be observed by liquid chromatography. Samples produced with heavy pressed musts presented a higher browning index. Furthermore, the application of pressure to the grape musts during winemaking increased the contents of total glutathione by factors of up to 22 and 15 for light pressed and heavy pressed musts, respectively. After 8 months of bottle ageing, the glutathione content decreased in all samples.     

Distinguishing organic wines from normal wines on the basis of concentrations of phenolic compounds and spectral data

This study was undertaken to determine whether it is possible to distinguish organic wines from normal wines on the basis of chemical composition and spectral data. A total of 58 wine samples including organic and normal red and white wines from France and Germany were analysed. The concentrations of several phenolic compounds, including trans-resveratrol, were determined using reversed-phase high-performance liquid chromatography with both diode array and coulometric electrode array detection. In addition, total phenols, total acids, pH and SO₂ were determined. The ultraviolet-visible (UV-vis) spectra of wines were measured, and the absorbances at four different wavelengths were determined. The data were processed statistically using principal component analysis (PCA). Despite several different combinations of variables, separation of white wines was only achieved according to geographical origin. PCA differentiated well between organic Burgundy red wines and normal Burgundy wines. The separation was based on the concentrations of caffeic and gallic acids, total phenol content and the absorbance ratios A₂₅₄/A₂₇₆, A₂₇₆/A₃₂₀ and A₃₂₀/A₅₂₀. PCA was unable to differentiate organic white wines from corresponding normal wines. The mean trans-resveratrol concentrations of 16 organic red wines and 16 normal red wines were 5.6 mg/l and 2.9 mg/l, respectively. The highest concentration, 14,5 mg/l, was found in an organic red wine from the Loire district in France.     

The application of an improved method for trans-resveratrol to determine the origin of Greek red wines

A rapid and sensitive method has been developed for the determination of trans-resveratrol in wine. This method consists of a solid phase extraction step followed by a rapid HPLC quantification step (30 min). The improvement of this method consists of the washing step of the solid phase extraction method carried out at pH 8.0 (12% ethanol in a phosphate buffer solution), thus permitting a more efficient removal of the interfering phenolic compounds in conjunction with the required low volume of tested sample. Trans-resveratrol content was determined for 29 red Greek wines of appellation of origin. The concentrations found varied between 0.550 and 2.534 mg/l. The wines produced by grape varieties grown in the Greek islands (Rhodes, Crete and Paros) were richer in trans-resveratrol. The grape variety Mandilaria, in particular, was the Greek variety with the highest trans-resveratrol content.     

Detection of ochratoxin A and cis- and trans-resveratrol in red wines and their musts from Calabria (Italy)

The natural occurrence of ochratoxin A (OTA) and cis- and trans-resveratrols in red wines has been widely reported. The aim of this work was to evaluate the ochratoxin A (OTA) and both cis- and trans-resveratrol content of red wine (from must to wine) in a pilot-scale vinification process in Calabria (Italy). Eleven samples were collected at different stages of vinification and analysis was carried out by HPLC. Wine from manufacturer 3 contained the highest amount of trans-resveratrol (3.41?mg?l^?1). This wine was characterized by an Aglianico–Magliocco grape variety. Interestingly, data regarding OTA showed that the value of this contaminant was low in all analyzed samples and, in each case, below the legal limit (2.0?mg?l^?1 (ppb)). Overall, the results demonstrated the high quality of wines produced in Calabria.     

Characterization of Polish Wines Produced from the Multispecies Hybrid and Vitis vinifera L. Grapes

Phenolic profile, antioxidant activity, and color parameters of Polish wines, produced from the multispecies hybrid and Vitis vinifera L. grapes were analyzed. A principal component analysis was applied, in order to differentiate the investigated wines in terms of content of phenolic compounds. The white wines turned out to be similar to each other in terms of color parameters and the results of principal component analysis, while the red wines strongly differed in this respect. However, the white wine produced from the multispecies hybrid grapes contained a higher level of phenolic acids and flavonoids, as compared to the white wines obtained from the hybrid cultivars. Out of the red wines, Rondo wine, produced from the multispecies hybrid grapevine was the richest in total phenolic and phenolic acids content. Caffeic acid and quercetin were the predominant phenolics in majority of the wines tested.     

Comparison of polyphenols and aroma in red wines from Portuguese mainland versus Azores Islands

trans-Resveratrol (trans-3,5,4′.trihydroxystilbene), piceid (resveratrol 3-O-β-D-glucopyranoside), together with their isomers and quercetin were measured in red wines from cultivars grown in Portuguese mainland and Azores Islands. Crude hydroxystilbenes and quercetin were extracted by solid-phase extraction-C₁₈ cartridges, and eluted with ethyl acetate. Recoveries of added trans-resveratrol and quercetin were between 90.2 to 101% (mean 96.8%) and between 95.2 and 97.6% (mean 96.2%), respectively. The precision measured by coefficients of variation (overall mean) ranged from 1.8 to 3.3%, and the calibration curves were linear with the mean correlation coefficients of 0.9997 and 0.9978 for trans-resveratrol and quercetin, respectively. The wine polyphenolic compounds were separated by reverse-phase C18 HPLC column and identified by UV fast scanning, retention times and HPLC/MS. The average content of total stilbenes was 4.75 and 6.33 mg/l, that of quercetin was 4.38 and 5.57 mg/l, and the trans/cis ratio was 8.32 and 10.89 for piceid and 5.2 and 4.09 for resveratrol in Portuguese mainland and Azorean wines, respectively. The Azorean wine (Basalto) was notable in having the highest trans-resveratrol concentration. The aroma profile of red wine samples from different regions were compared using SPME/GC-MS headspace methodology.     

Determination of trans-resveratrol in red wine by adsorptive stripping square-wave voltammetry with medium exchange

In the present paper, a method for the determination of trans-resveratrol in red wine samples, by adsorptive stripping square-wave voltammetry (Ad-SSWV) in a glassy carbon electrode, is presented. In 0.10 M perchloric medium, trans-resveratrol experiments an adsorptive–oxidative process, which promotes the appearance of a peak at 0.72 V. Calibration graph have been constructed from 5.0 to 35 ng/mL. Detection limit of 4.2 ng/mL has been calculated, according to Clayton criterion. Extraction of trans-resveratrol from red wine with diethylether and posterior clean-up with C18 cartridges is carried out. Recovery percentages close to 100% have been calculated with different red wine samples. The accumulation of analyte in the electrode is carried out at +0.60 V for 60 s, in the presence of 0.10 M HClO₄ and 10% of ethanol; the measurement stage is performed after a medium exchange, in 0.10 M HClO₄ and 30% of ethanol. The standard addition method was employed for the analysis of real samples, since a matrix effect is observed in red wine extract. The method has been applied to several commercial red wines samples, and the results have been satisfactorily validated by HPLC.     

Polyphenols,anthocyanins, and trans-resveratrol in red wines from the Hungarian Villány region

Epidemiological data indicate that moderate red wine consumption leads to less coronary heart disease and shows anti-carcinogenic effects. Especially, red wine phenolics have been linked to these effects. Sixty-seven red wines from the Hungarian Villány region, of vintages from 1996 to 2003 were analysed for their polyphenolic and anthocyanin composition by means of RP-HPLC/UV–Vis. Varieties with generally high concentrations of polyphenols are Kékfrankos, Merlot and Zweigelt, while anthocyanin content was highest in Shiraz, Oportó, Kékfrankos and Zweigelt. In agreement with other authors, our results show that trans-resveratrol content is mainly dependent on variety and vintage year. Principal component analysis (PCA) revealed that flavan-3-ols and delphinidin- and petunidin-3-glucosides are mainly responsible for the separation of wines according to polyphenolic composition. We could not discriminate between varieties or wineries based on polyphenol content, but could for vintage years.     

Influence of some technological practices on the quantity of resveratrol in wine

A study of the effects of some prefermentative and fining practices on the resveratrol concentration in wine was carried out. The trans- and cis-resveratrol contents in a red wine obtained using must hyperoxidation were reduced to about 50% compared with those of control wines; this decrease was greater than that observed for total phenols and catechins. In contrast, sparging the red grapes with SO₂ and ascorbic acid before crushing them resulted in the trans-resveratrol concentration being greater than that of the control wines. Moreover the amounts of trans- and cis-resveratrol in commercial and synthetic wines were determined before and after addition of charcol, polyvinylpolypyrrolidone (PVPP), bentonite, casein, gelatine, and two inert materials, cellulose and diatomaceous earth (kieselgur), used as a filter aid. The results showed that PVPP, charcoal and casein were more effective at removing trans- and cis-resveratrol both in synthetic wine and in commercial wines. In all the wines tested the other fining agents gave a limited decrease (2?–?5%) of trans- and cis-resveratrol. After charcoal and PVPP treatments, significant correlations were observed between the percentage of residual resveratrol and the total phenols in the wines.     

Antioxidant activity and phenolic content of 16 raisin grape (Vitis vinifera L.) cultivars and selections

Six raisin grape cultivars and 10 new raisin grape selections were analyzed for antioxidant activity (ABTS assay) and for total and individual phenolic compounds. Samples were freeze–dried and values are reported on a dry weight basis. Antioxidant activity across the 16 samples ranged from 7.7 to 60.9 μmol Trolox/g DW, with A95-27 exhibiting the greatest activity. Total phenolic content, determined in gallic acid equivalents using the Folin–Ciocalteau assay, ranged from 316.3 to 1141.3 mg gallic acid/100 g DW and was strongly correlated (r = 0.990) with antioxidant results. Concentrations of individual phenolics were determined by HPLC. trans-Caftaric acid was the predominant compound in all samples. A95-15 contained the lowest concentration (153.5 μg/g DW) of caftaric acid, while Fiesta contained the highest concentration (598.7 μg/g DW). Selections A56-66, A95-15, and A95-27 had much higher levels of catechin (86.5–209.1 μg/g DW) and epicatechin (126.5–365.7 μg/g DW) than the other samples.     

An Alternative Method for the Determination of Some of the Antioxidant Phenolics in Varietal Turkish Red Wines

The concentration of eight biologically important phenolic compounds (β‐coumaric acid, gallic acid, ferulic acid, caffeic acid, trans‐resveratrol, quercetin, (+)‐ catechin and (?)‐ epicatechin) of red wines produced on a pilot plant scale were determined using gas chromatography with mass spectrometric detection in the selective ion monitoring mode (GC/MS‐SIM). The procedure involved an easy fractionation and liquid‐liquid extraction method. For derivatization, BSA [N,O‐bis‐trimethylsilyl aceta‐mide] / TMCS was used. The results showed that the p‐coumaric acid, gallic acid, ferulic acid, caffeic acid, trans‐resveratrol, quercetin, (+)‐ catechin and (?)‐epicatechin levels in the wine samples ranged between 2.05 and 4.21 mg/L; 21.78 and 60.83 mg/L; 0.33 and 0.82 mg/L; 1.50 and 4.06 mg/L; 0.96 and 3.93 mg/L; 2.66 and 3.14 mg/L; 8.72 and 11.30 mg/L; 5.50 and 9.58 mg/L, respectively. Although the quercetin and trans‐resveratrol levels of Turkish red wines were similar to previously reported values, (+)‐ catechin and (?)‐ epicatechin levels were lower than the values of red wines originating from other countries.     

Proanthocyanidin profile and antioxidant capacity of Brazilian Vitis vinifera red wines

The free flavan-3-ol and proanthocyanidin (PA) profile and the antioxidant capacity of wines Vitis vinifera L., 2006 and 2007 vintages, from the São Joaquim region, at southern Brazil, are reported here for the first time. Catechin and epicatechin were the two main monomers in the wine samples, followed by gallocatechin and epigallocatechin; and the PA B1 was the main dimer. The terminal units of the PAs were constituted mainly by catechin units, with the co-presence of epicatechin, gallocatechin, epigallocatechin and traces of epicatechin gallate. The epicatechin and epigallocatechin units were the main constituents of the extension units of PAs with the co-presence of catechin and epicatechin gallate. The values for the mean degree of polymerisation ranged from 4.9 to 9.8. The wine samples demonstrated effective scavenging activity against DPPH and ABTS radicals and against lipid peroxidation in vitro. A positive correlation existed between flavan-3-ol content and antioxidant capacity in vitro.     

Stilbene levels and antioxidant activity of Vranec and Merlot wines from Macedonia: Effect of variety and enological practices

The content of the stilbenes trans-resveratrol and piceid as well as the antioxidant activity of Macedonian red wines from the two main grape varieties Vranec and Merlot have been evaluated. Тhe effects of time of maceration, type of yeast and the level of sulphur dioxide applied on stilbene content and antioxidant activity have been studied. The most important factor in winemaking technology is the maceration time since the highest concentrations of trans-resveratrol, piceid and highest antioxidant activity were found following 6 and 10 days of maceration. Concerning the yeast type, higher concentrations of trans-resveratrol and piceid have been obtained with French yeast “Levuline CHP” in comparison to Macedonian yeast “Vinalco”. In contrast, the higher antioxidant activity of wines from both varieties of grapes was observed by application of Macedonian yeast “Vinalco”.     

Nutritional composition of commercial pickled garlic

The effect of pulp treatment on the qualitative and quantitative changes to polyphenol compounds, such as anthocyanins and flavanols, in musts and wines from blackcurrant and cherries was investigated. The following variants of pulp treatment were used: hot maceration, hot maceration and pulp pectinolysis with Rohapect MA Plus and Pectopol PM preparations, and also pulp pectinolysis with Rohapect and Pectopol preparations. The method of treatment affected the content of anthocyanins and flavan-3-ols in the musts. Different types of phenolic compounds reacted differently under must-making conditions. Wines made with different treatments presented statistical differences with the control wine and between them for the parameters studied.As a result of the analysis of cherry musts and wines by HPLC, the following flavan-3-ols were identified: catechin, epicatechin, dimer B₂ and trimer C₁. In the cherry wines studied, in the variants subjected to pectinolysis and fermentation in the pulp, epicatechin occurred in a smaller amount than catechin, while in the wines subjected to thermal treatment it was predominant. In the blackcurrant musts and wines the following flavanols were identified: gallocatechin, catechin, epigallocatechin, dimer B₂, epicatechin and trimer C₁. In the cherry musts and wines the following anthocyanin pigments have been identified: cyanidin 3-glucoside, cyanidin 3-rutinoside and cyanidin 3-glucosylrutinoside, the amount of which was the greatest. Anthocyanins identified in the blackcurrant musts and wines were delphinidine and cyanidine glycosides: delphinidin 3-glucoside, delphinidin 3-rutinoside, cyanidin 3-glucoside and cyanidin 3-rutinoside; their aglycones were also found.     

A review of the content of the putative chemopreventive phytoalexin resveratrol in red wine

Resveratrol, a naturally occurring compound of various fruits such as grapes, is thought to possess chemopreventive properties. The levels of resveratrol in grapes and grape products including wine, varies from region to region and from one year to another. This paper reviews the resveratrol content in red wine based on relevant published data. Red wine contains an average of 1.9 ± 1.7 mg trans-resveratrol/l (8.2 ± 7.5 μM), ranging from non-detectable levels to 14.3 mg/l (62.7 μM) trans-resveratrol. In general, wines made from grapes of the Pinot Noir and St. Laurent varieties showed the highest level of trans-resveratrol. No region can be said to produce wines with significantly higher level of trans-resveratrol than all other regions. Levels of cis-resveratrol follow the same trend as trans-resveratrol. The average level of trans-resveratrol-glucoside (trans-piceid) in a red wine may be as much as 29.2 mg/l (128.1 μM), i.e., three times that of trans-resveratrol.     

Prebiotic effects of yacon (Smallanthus sonchifolius Poepp. & Endl), a source of fructooligosaccharides and phenolic compounds with antioxidant activity

Montepulciano is one of the most famous and important red-berried grapes of Italy. This article presents and discusses a comparative study of aroma profile and phenolic content of the Montepulciano wine from the Marches and the Abruzzo regions. The volatile composition of wines was determined by using headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The PDMS fibre was chosen. The dominating esters in Montepulciano wines were ethyl hexanoate, ethyl decanoate, and ethyl octanoate, whereas phenyl ethanol and 3-methyl-1-butanol were dominating alcohols.Phenolic compounds, namely gallic acid, p-coumaric acid, trans-ferulic acid, caffeic acid, trans-resveratrol, (+)-catechin and (−)-epicatechin, were examined using HPLC-MS with direct injection of wine samples. The total phenolic content of the analysed wines was in the range of 30.4-61.9 mg l⁻¹. The presence of high amounts of esters seems to characterise the volatiles of Montepulciano wines from the Marches, whereas a high level of alcohols was found in Montepulciano wines from Abruzzo. Moreover, multivariate chemometric techniques, such as cluster analysis and principal component analysis, supported this thesis. Headspace solid phase microextraction and gas chromatography-mass spectrometry were used to analyse 20 commercial wine samples (Montepulciano monovarietal red wines) from the Marches (10 samples) and Abruzzo (10 samples).     

Matrix effects on the bioavailability of resveratrol in humans

The pharmacokinetics of resveratrol in 11 healthy male volunteers has been assessed in a randomized, crossover, controlled clinical trial after the administration of three grape products: red wine (250 mL), grape juice (1/L), or tablets (red wine extracts enriched with trans-resveratrol). Doses of trans-resveratrol independently of the product administered, were about 14 μg/kg. Biological samples were collected and analysed by capillary gas chromatography–mass spectrometry. cis-Resveratrol, trans-resveratrol and dihydroresveratrol were determined in plasma and urine. Plasma concentration of trans-resveratrol after hydrolysis increased as a response to all grape products and that of cis-resveratrol after wine and grape juice. Free forms of these phenolic compounds were deemed undetectable in plasma. Despite similar trans-resveratrol doses being administered, its bioavailability from wine and grape juice was 6-fold higher, than that from tablets. Resveratrol was better absorbed from natural grape products than from tablets, pointing out the importance of the matrix in its bioavailability.     

Characterization of Goethe white wines: influence of different storage conditions on the wine evolution during bottle aging

The aim of this study was to characterize Goethe white wines, produced in the region around Urussanga, Santa Catarina State, Brazil, in terms of their organic acids and polyphenols content, browning index, and in vitro antioxidant activity and to evaluate the evolution of these wines during bottle storage under two distinct conditions. The wines were analyzed utilizing spectrophotometry and liquid chromatography. In relation to the phenolic compounds investigated, trans-caftaric acid was the major component in all samples, ranging from 42.63 to 52.31 mg L^?1, followed by catechin (18.90 to 28.09 mg L^?1) and epicatechin (2.68 to 4.35 mg L^?1). Samples with higher levels of total polyphenols also had higher antioxidant activity. The antioxidant activity, total polyphenols content, and browning index increased with storage. Quercetin showed the strongest correlation (R = 0.84) with antioxidant activity before and after bottle aging. Samples kept at room temperature with light exposure presented greater degradation of phenolic compounds and lower browning index values than the samples stored under controlled conditions. Principal components analysis (PCA) separated the samples according to storage conditions and wine samples. The results clearly verified that the factors light, temperature, and bottle position affected significantly the chemical composition of white wines.