Search Results

You are looking at 1 - 10 of 97 items for :

Clear All

catechin directly from red wine with higher affinity prior to chromatographic analysis; (3) to optimize and validate method for the analysis of catechin compounds in red wines by HPLC; and (4) to compare between the results obtained with MIP cartridges and

Open access

. ( 2013 ): Effects of red wine polyphenols and alcohol on glucose metabolism and the lipid profile: a randomized clinical trial . Clin Nutr. , 32 , 200 – 206 . Dupont

Open access

of red wines.) Ind. Bevande , 29 , 606–612. Simoni M. Effetto dell’ossigenazione controllata sulla frazione fenolica dei vini rossi Ind

Restricted access

. Avizcuri , J-M. , Sáenz-Navajas , M-P. , Echávarri , J-F. , Ferreira , V. & Fernández-Zurbano , P. ( 2016 ). Evaluation of the impact of initial red wine composition on changes in colour and anthocyanin content during bottle

Restricted access

Nine phenolic compounds (gallic acid, (+)catechin, vanillic and caffeic acid, p-coumaric acid, resveratrol, myricetin, quercitrin and quercetin) of fourteen Eger (Hungarian) young red wines were investigated using high-performance liquid chromatography in order to obtain data on the 2003 vintage. The grapes were harvested at different sites of the wine-district, vinified with same technology, but stored under different conditions (glass holder or 5-10 years old oak barrel). Same varietal wines originating from different sites of Eger wine-region showed considerable alterations in some phenolic components, and we found distinction in polyphenol content of different varietal wines originating from the same harvesting site. Cluster analysis was performed to acquire information about the similarity among the measured wines. Our study provides new data of polyphenol composition for Eger (Hungary) pure varietal red wines, and the results contribute to better identification of Hungarian red wines on the basis of geographical location.

Restricted access

A simple method is described for separation and determination of the isomers of trans -resveratrol and related compounds from different types of red wine by overpressured layer chromatography (OPLC). Comparison of OPLC with TLC clearly showed the advantages of the forced-flow technique (higher theoretical plate number, good resolution, etc.) over conventional planar layer liquid chromatography. It was established that the glycosides of resveratrol isomers were always present in higher concentrations than free stilbene isomers in red wine samples. This was especially true for the Pinot Noir wine. Exploitation of the advantages of OPLC provides further possibilities of analysis and isolation of stilbene isomers from grapes and wine.

Restricted access

An HPTLC method has been developed to give qualitative and quantitative information on red wine pigments. The samples are prepared by solid-phase extraction (SPE) on C 18 cartridges. Analytical determination is done by chromatography on C 18 silica gel plates with isocratic elution with methanol-water-trifluoracetic acid, 55 + 45 + 1 ( v/v ). This method leads to the clear separation of the three classes of Vitis vinifera anthocyanins with good statistical repeatability and reproducibility for wines of different vintages. It also enables evaluation of the amount of polymeric pigments in red wines.

Restricted access

The potential health benefits of wine are frequently attributed to the antioxidant properties of its phenolic constituents. In this study, the antioxidant efficacies of five phenolic components of a red wine were assessed in the presence of hydrogen peroxide (H2O2) and metal ions ([Fe3+], [Fe2+], [Cu2+]), using functional thin-layer chromatography (TLC). The pH of the red wine sample was adjusted to 2.0 without prior extraction. Chromatographic separation was performed using silica gel 60 F254 TLC plates with toluene-ethyl acetate-formic acid 30:25:5 (ν/ν) as mobile phase. Five phenolic components (one flavonol and four phenolic acids) were identified. In independent experiments, the red wine was challenged with a range of oxidant systems comprising H2O2, redox-active metals (Fe3+ and Cu2+), and hydroxyl radical generators (Fe2+-H2O2 and Cu2+-H2O2). The results showed that all phenolic compounds gradually diminished in a concentration- and time-dependent manner. All systems tested showed that quercetin, caffeic acid, and gallic acid possessed the highest antioxidant efficacies, while chlorogenic acid and p-coumaric acid exhibited lower antioxidant capacities. Based on these results, the ranking order of the antioxidant efficacies of the phenolic components in the red wine sample was as follows: quercetin > caffeic acid > gallic acid > p-coumaric acid > chlorogenic acid. This is the first application of functional TLC to delineate the antioxidant profile of red wine in the presence of different oxidant systems involving redox-active metals and H2O2, and to rank the individual components according to their antioxidant efficacies.

Restricted access

This study demonstrated the suitability of high-performance thin-layer chromatography using a charge-coupled device (CCD) for acquisition of fluorescence images of ochratoxin (OTA), as a tool for analysis of this toxin in red wine. The mean recovery of the method was 92%. The quantification and detection limits were 0.1 μg L −1 and 0.32 ng per spot, respectively. Results from validation confirmed the efficiency of the method, which is sensitive enough to be used by producers and governments for quantification of OTA in wine in monitoring and survey programs. The occurrence of OTA in 34 Brazilian red wines was evaluated and one of the samples contained OTA at a level above the quantification limit.

Restricted access
Acta Alimentaria
Authors: M. Atanacković Krstonošić, J. Cvejić Hogervorst, Lj. Torović, V. Puškaš, U. Miljić, M. Mikulić and Lj. Gojković Bukarica

Most of red wine's health benefits are attributed to polyphenols, which can express different biological effects. During ageing process, numerous chemical reactions occur, alternating phenolic composition of wine. Therefore, this paper focused on the influence of ageing on the evolution of wine phenolics (phenolic acids, flavonoids, stilbenes, and anthocyanins). Wines from 4 local grape varieties (Frankovka, Portugieser, Probus, and Rumenika) were analysed after 1 month and 4 years of ageing. Monomeric anthocyanin and total phenolic contents and antioxidative potential in aged wines were also determined. Among tested phenolics, main components in aged wines remained gallic acid (2.16–19.55 mg l−1) and catechin (8.39–37.21 mg l−1). The most prominent changes of analysed phenolic compounds during ageing were observed for p-coumaric acid (from +173.3% to +763.1%) and malvidin-3-glucoside (from +173.3% to +763.1%). Wine from Rumenika variety maintained the highest content of individual phenols after ageing. Additionally, aged wines had very low content of monomeric anthocyanins. Significant correlation (r= −0.93, P<0.05) between total phenolic content and IC50 values in aged wines was also noticed. Obtained results provide useful information about the quality preservation during aging and storage of these products.

Restricted access