Classification of Spanish white wines using their electrophoretic profiles obtained by capillary zone electrophoresis with amperometric detection

Abstract

A method was developed for the simultaneous detection of eight polyphenols (t-resveratrol, (+)-catechin, quercetin and p-coumaric, caffeic, sinapic, ferulic, and gallic acids) by CZE with electrochemical detection. Separation of these polyphenols was achieved within 25 min using a 200 mM borate buffer (pH 9.4) containing 10% methanol as separation electrolyte. Amperometric detection of polyphenols was carried out with a glassy carbon electrode (GCE) modified with a multiwalled carbon nanotubes (CNT) layer obtained from a dispersion of CNT in polyethylenimine. The excellent electrochemical properties of this modified electrode allowed the detection and quantification of the selected polyphenols in white wines without any pretreatment step, showing remarkable signal stability despite the presence of potential fouling substances in wine. The electrophoretic profiles of white wines, obtained using this methodology, have proven to be useful for the classification of these wines by means of chemometric multivariate techniques. Principal component analysis and discriminant analysis allowed accurate classification of wine samples on the basis of their grape varietal (verdejo and airén) using the information contained in selected zones of the electropherogram. The utility of the proposed CZE methodology based on the electrochemical response of CNT-modified electrodes appears to be promising in the field of wine industry and it is expected to be successfully extended to classification of a wider range of wines made of other grape varietals.

Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

“…CE detection often relies on UV spectroscopy using diode array devices, but other techniques, such as amperometric detection (AD), have also been found to be very useful for the analysis of wines . For ED, 1 mm diameter glassy carbon electrodes were used.…”

Liquid Chromatographic Approach for the Discrimination and Classification of Cava Samples Based on the Phenolic Composition Using Chemometric Methods

“…In order to go into detail in the characterization of potential markers of wines classes defined by origins, varieties, blends, vintages, etc., HPLC with mass spectrometry (MS) detection is able to generate a rich set of discriminant features that could further submitted to structural elucidation [20,21]. Apart from HPLC, other separation techniques have been used such as thin-layer chromatography [22], GC-MS [23] and capillary zone electrophoresis [24,25].…”

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“…29 Red grapes and red wines earn star status for their high levels of resveratrol, with Spanish grapes taking the top prize, providing as much as 1,890 micrograms in a 5-ounce glass. 30,31 Grapes only have resveratrol in the skins and the amount varies according to the type of grape and whether the plant is exposed to fungal infection, a form of stress that the plant responds to by producing resveratrol to fend off infection. 32,33 Metabolism and Bioavailability: Since much of the basic research on resveratrol has been conducted in cultured cells exposed to unmetabolized resveratrol at concentrations, often 10-100 times greater than peak concentrations observed in human plasma after oral consumption, the information about the bioavailability of resveratrol in humans is important.…”