Resveratrol In Wine Research Articles

Resveratrol and a novel tyrosinase in Carignan grape juice.

Polyphenol levels in wines are affected by the wine-making process. Resveratrol is one polyphenol which has been the subject of a commendable amount of recent research. In this work, we found that resveratrol is immediately degraded by tyrosinase. A novel tyrosinase was purified from Carignan grapes. The purification process included salting out and separation on a cation-exchange column, followed by gel filtration. Tyrosinase was purified in a homogeneous form by SDS-PAGE and was characterized: its specific activity toward 3-(3,4-dihydroxyphenyl)-L-alanine (DOPA) increased by a factor of 24 with an overall recovery of 3% of initial activity. The apparent molecular mass of the purified tyrosinase was 40 kDa as determined by SDS-PAGE, and 42 kDa as determined by gel filtration. Its activity was optimal at pH 6 and at 25 degrees C. The enzyme exhibited high activity toward phenylenediamine, epicatechin, pyrogallol, DOPA, and resveratrol. Tyrosinase activity was inhibited by KCN, thiourea, and SO(2). Resveratrol levels were stable following the removal of proteins from the juice, suggesting that early spraying of grapes with SO(2) is an important factor affecting the final amount of resveratrol in wine.

Biological control ofBotrytis cinereacausing grey mould disease of grapevine and elicitation of stilbene phytoalexin (resveratrol) by a soil bacterium

Botrytis cinerea Pers. was found to be highly pathogenic to the grapevine plant, producing the characteristic grey mould symptoms within 7 days of inoculation on vitroplants. A bacterial strain, isolated from soil, belonging to the genus Bacillus was found to be an antagonist of this disease causing fungus. The fungal attack on the grapevine acts as an elicitor to the production of phytoalexines like resveratrol. This compound was also formed when the leaves of the grapevine vitroplants were inoculated with the bacteria alone, and this activity was enhanced when a mixture of the pathogen and the antagonist bacteria was applied. Since resveratrol in wine is considered to be beneficial to human health provided moderate consumption, this bacteria can be used as a potential biological control agent as well as a biological elicitor of resveratrol. The article includes the details of the fungal parasite, its biological control and resveratrol elicitation.

Biological control of Botrytis cinerea causing grey mould disease of grapevine and elicitation of stilbene phytoalexin (resveratrol) by a soil bacterium

Botrytis cinerea Pers. was found to be highly pathogenic to the grapevine plant, producing the characteristic grey mould symptoms within 7 days of inoculation on vitroplants. A bacterial strain, isolated from soil, belonging to the genus Bacillus was found to be an antagonist of this disease causing fungus. The fungal attack on the grapevine acts as an elicitor to the production of phytoalexines like resveratrol. This compound was also formed when the leaves of the grapevine vitroplants were inoculated with the bacteria alone, and this activity was enhanced when a mixture of the pathogen and the antagonist bacteria was applied. Since resveratrol in wine is considered to be beneficial to human health provided moderate consumption, this bacteria can be used as a potential biological control agent as well as a biological elicitor of resveratrol. The article includes the details of the fungal parasite, its biological control and resveratrol elicitation.

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.

Direct Analysis of Resveratrol in Wine by Micellar Electrokinetic Capillary Electrophoresis.

Resveratrol is an antioxidant found in grapes and other plants. It has been reported to have health benefits including anticarcinogenic activity and protection against coronary heart disease. Previous methods for its quantification in wines have relied on HPLC and GC. However, an alternative method utilizing capillary electrophoresis (CE) has been developed in our laboratory. The CE procedure resolves cis- and trans-resveratrol isomers, using a micellar mode of separation. The detection limit for resveratrol was 1.25 µM using UV detection at 310 nm. This procedure was employed for the direct analysis of trans-resveratrol in wines. The direct analysis method used was advantageous because the analysis time was greatly reduced and sample preparation procedures that might result in resveratrol isomerization were avoided. The CE procedure was used to determine the level of trans-resveratrol in several California red wines, and the values obtained were in close agreement with those reported using other methods.

Resveratrol in Wine: Extraction From Skin During Fermentation and Post-fermentation Standing of Must From Gamay Grapes

Resveratrol (<i>cis</i>- and <i>trans</i>-isomers) was analyzed in skin, seeds and must of grape berries of Gamay from starting must to skin separation and in wine after malolactic fermentation. Its concentration increases in must while decreasing in skin and remains quite constant in seeds during alcoholic fermentation. Extraction from the skin correlates well with the increase of ethanol concentration in must up to day 6. After malolactic fermentation, the amount of resveratrol is about twice that measured at the end of alcoholic fermentation indicating a pool of resveratrol probably in the form of glucosides and (or) as on oligomeric form from which free resveratrol could be liberated by enzymatic activity of malolactic bacteria.

Hydroxylated Stilbenes in Selected American Wines

Hydroxylated stilbene contents of a number of commercial American red wines were determined by gas chromatography−mass spectrometry. Six stilbenols were eluted. Two of these were identified as cis and trans isomers of 3,5,4‘-trihydroxystilbene (resveratrol), while the others were tentatively identified as mono-, di-, tri-, and tetrahydroxystilbenes. cis- and trans-resveratrol were present in the wines at concentrations ranging from 0.1 to 31.9 ppm for cis and from 0.0 to 13.4 ppm for trans. The concentrations of resveratrol in wines made from Vitis rotundifolia (muscadine) grapes were higher (P > 0.05) than those present in wines made from Vitis vinifera and Vitis labruscana grapes. Tetrahydroxy contents of Muscadine and Concord wine were, in general, lower than that of the V. vinifera wines. A method for analyzing hydroxylated stilbene compounds in wine by flame ionization detection is reported. Keywords: Resveratrol; stilbenol; red wine; muscadine; Vitis

Concentration of resveratrol in wines from Catalonia, Spain

Abstract The concentration of thetrans and cis isomers of resveratrol (3,5,4’ ‐trihidroxystilbene) was analysed in 121 commercially available wines from within the Catalonia and Cava appellation areas. The trans‐resveratrol was detected at an average concentration of 0.12 mg l‐1 in white wine, 0.09 mg l‐1 in cava, 0.28 mg l‐1 in cava (rosé), 0. 56 mg l‐1 in rosé and 1.78 mg l‐1 in red wine. The average values for the cis isomer were 0.12 mg l‐1 in white wine, 0.09 mg l‐1 in cava, 0.20 in cava (rosé), 0.58 mg l‐1 in rosé and 1.33 mg l‐1 in red wine.

Analysis of resveratrol in Burgundy wines

Recent studies have shown that resveratrol (3,5,4'‐trihydroxystilbene), a phytoalexin related to grape disease resistance, could occur in American and Bordeaux wines. It was also suggested that resveratrol might have cardioprotective activities in humans, as a result of drinking wine. We report here the presence of this compound in Burgundy wines. Analysis of resveratrol in wine was carried out using gas chromatography and gas chromatography—mass spectrometry.

Concentration of the Phytoalexin Resveratrol in Wine

Resveratrol is a phytoalexin found in grapes. Recent research had shown that orally administered resveratrol lowered lipid levels in the liver of rats. Wine had been shown to lower serum lipid levels in humans. The concentration of resveratrol was measured in selected wines using HPLC and spectrophotometry. Geographical origin, variety, growing methods, and winemaking procedures all seemed to affect resveratrol concentration. Analysis of wines indicated that resveratrol may be the active ingredient in wines causing reduction of serum lipids.