Automated solid-phase extraction for sample preparation followed by high-performance liquid chromatography with diode array and mass spectrometric detection for the analysis of resveratrol derivatives in wine.
ABSTRACT A method has been developed for the simultaneous determination of resveratrol in all its forms (free isomers and glycosylates) in wines by high-performance liquid chromatography with diode array and mass spectrometric detection. Prior to injection into the column, preconcentration of the sample by automated solid-phase extraction is carried out. In the detection by UV absorption, quantitation was carried out at 280 and 305 nm, and in detection by mass spectrometry, quantitation was performed in the selected ion monitoring mode at m/z 228 and at m/z 238. A comparative study between both detection systems was carried out.
- SourceAvailable from: Enrique J. Martinez de la Ossa[show abstract] [hide abstract]
ABSTRACT: Resveratrol is a phenolic compound that is present in grapes and has significant benefits for human health. The development of methods to obtain concentrates of this compound is currently a major challenge in the food industry. In the work described here, resveratrol from grape seeds, stems, skin and pomace of the Palomino fino grape variety was extracted by supercritical carbon dioxide extraction. The effect of pressure (100, 400 bar), temperature (35, 55 °C) and the addition of modifier (5% v/v of ethanol) was evaluated to identify optimal resveratrol extraction from this by-product. Extraction yields and concentrations of resveratrol in the extracts were determined. The best results were obtained on working at high pressure and low temperature using 5% v/v ethanol as a co-solvent.Journal of Food Engineering. 01/2010;
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ABSTRACT: A simple CZE method has been developed for the simultaneous determination of eight polyphenolic compounds. The influence of several experimental conditions such as buffer (concentration and pH) and temperature were studied. Optimum separation was achieved in less than 25 min by using a BGE of 50 mM Na(2)B(4)O(7) and 10 mM Na(2)HPO(4) at pH 9.6, a temperature of 25°C and an applied voltage of 25 kV. Good linearities for all eight analytes were obtained with correlation coefficients higher than 0.99. The LODs were between 0.03 and 5.05 μg/mL and the RSD values of the migration times were found to be less than 1%. The optimal separation conditions were then used for the identification and the quantitation of polyphenolic compounds in Cypriot wine samples using six different sample preparation procedures. In particular, two direct injection methods (without any extraction step), three different liquid-liquid extraction procedures and an SPE procedure were examined. These sample pre-treatment methods were also compared in order to determine the one that is the most effective, in regard to analyte recovery, time, difficulty, and reproducibility. Liquid-liquid extraction using diethyl ether as the organic solvent proved to be the most effective.Electrophoresis 11/2010; 31(23-24):3895-902. · 3.26 Impact Factor
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ABSTRACT: Resveratrol-enriched wine is considered an interesting new food product with added value as a consequence of the numerous health-promoting properties ascribed to it. Postharvest white grapes have been UVC-treated to produce stilbene-enriched grapes that were then used in a novel winemaking process to obtain a white wine enriched in resveratrol. For this goal UVC-treated grape pomace was added to must during alcoholic fermentation to increase stilbene extraction in wine. Wine from UVC grapes thus contained significant higher resveratrol content than its respective control. However, wine quality was compromised. The UVC wine showed high colour intensity, hue, and astringency due to the high extraction of other phenolic compounds additionally to resveratrol.Food Research International - FOOD RES INT. 01/2010; 43(8):2179-2185.