Development of a fractionation method for the detection and identification of oak ellagitannins in red wines

Abstract

During maturation and ageing in oak barrels wines improve their organoleptic properties. Ellagitannins can be released from wood to the wine and be involved in oxidation reactions and seem to influence the astringency and colour properties of the wine. Nevertheless, the ellagitannins levels are lower than those of other wine constituents and, consequently, they are not easily detected. This study has developed a two-step fractionation method consisting of a solid phase extraction in C-18 Sep-Pak cartridges followed by size exclusion chromatography in hand-packed Sephadex LH-20 minicolumn for the detection of oak ellagitannins in different types of wines. An HPLC method has also been developed which allows the separation of compounds with the same m/z ratios, facilitating the ellagitannin identification by means of the mass spectrometric analyses. The main oak ellagitannins (grandinin, vescalagin, roburin E and castalagin) were isolated, detected separately and identified in a spiked wine and in three real ones, proving the usefulness of the fractionation method.

Hydrolyzable tannin analysis in food

“…Mass spectrometry detectors also offer valuable information for the identification of HTs, the negative ion mode of electrospray ionisation generally being employed (Arapitsas et al, 2007;Buendi´a et al, 2010;Fischer et al, 2011;Franceschi, Vrhovsek, & Guella, 2011;García-Estévez et al, 2010;Gasperotti, Masuero, Vrhovsek, Guella, & Mattivi, 2010;Harborne & Williams, 2000;Hatano et al, 1988;Kool, Comeskey, Cooney, & McGhie, 2010;MuellerHarvey, 2001;Mullen, Yokota, Lean, & Crozier, 2003;Määttä, Kamal-Eldin, & Törrönen, 2003;Määttä-Riihinen et al, 2004;Reed, Krueger, & Vestling, 2005;Soong & Barlow, 2005). When positive ion mode is used, the metal adducts of Na and K are usually identified (Franceschi et al, 2011;Furuuchi et al, 2011).…”

Effect of the type of oak barrels employed during ageing on the ellagitannin profile of wines

“…wood (García-Estévez et al 2010). The identity of the pure ellagitannins was assigned from the data obtained in the HPLC-diode array detector-MS and in 1 H and 13 C nuclear magnetic resonance analyses (García-Estévez et al 2010) and compared with that in the literature (Glabasnia and Hofmann 2006;Fridrich et al 2008). (-)-Gallocatechin was purchased from Sigma-Aldrich (St Louis, MO, USA), and solvents (analytical grade) were purchased from Prolabo (Briare, France).…”

Wine Polyphenols: Potential Agents in Neuroprotection

“…In wine, hydrolyzable tannins arise during maturation and ageing of wines in oak barrels [86]. Castalagin and vescalagine are the main representative compounds of ellagic tannins [87]. Their levels are about 100 mg/L in aged white wines, while red wine levels are about 250 mg/L after aging in oak barrels for two or more years [15, 88].…”