Evaluation of Hungarian Wines for Resveratrol by Overpressured Layer Chromatography

A method, including solid phase extraction sample preparation, overpressured layer chromatographic separation and subsequent densitometric evaluation, was developed for measurement of total resveratrol (cis- and trans-isomers) content of wine. The amount of resveratrol was determined in wine samples from different winemaking regions of Hungary. The total resveratrol was high in Hungarian red wines (3.6–11 mg/L), and much lower in white ones (0.04–1.5 mg/L)

A grape and wine chemodiversity comparison of different appellations in Burgundy: Vintage vs terroir effects.

This study aimed at assessing the ability of high resolution Fourier Transform Ion Cyclotron Resonance - Mass Spectrometry (FTICR-MS) to differentiate grapes and corresponding wines from distinct vineyards managed by a same producer, according to complex chemical fingerprints. Grape extracts (at harvest) and corresponding wines from four different vineyards, sampled immediately after the alcoholic fermentation over three successive vintages, were analysed by FTICR-MS. Thousands of metabolites that are specific to a given vintage, or a given class (wine, skin or must) could be revealed, thus emphasising a strong vintage effect. The same wines were reanalyzed after a few years in bottle. Within the frame of this study, FTICR-MS along with multivariate statistical analyses could reveal significant terroir-discriminant families of metabolites from geographically close - though distinct - vineyards, but only after a few years of bottle ageing. It is supposed that the chemical composition of a wine holds memories of various environmental factors that have impacted its metabolic baggage at the moment of its elaboration. For the first time, such preliminary results indicate that non-targeted experiments can reveal such memories through terroir-related metabolic signatures of wines on a regional-scale that can potentially be as small as the countless "climats" of Burgundy

Authentication approach of the chemodiversity of grape and wine by FTICR-MS.

The metabolic composition of grapes and related wines results from a complex interplay between environmental, genetic and human factors which are not easily or possibly resolvable into their unambiguous individual contributions. Whether it is in the vineyard or in the cellar, several processes can indeed subtly modulate the characteristics of grape and wine, and these modulations often involve 'trace' amounts and interplay of metabolites within a complex matrix. As a consequence, considering wine as a complex biological system, the whole of which being more than the sum of its parts, is likely to provide deeper understanding of specificities associated with varieties and/or geographical origins and/or wine making practices. We show that non-targeted analyses of grape and wine products by ultrahigh resolution mass spectrometry can reveal snapshots of their chemodiversities, and that these chemodiversities, characterized by thousands of metabolites, precisely hold fingerprints of specific environmental parameters such as the "terroir" of a wine or even of oaks used for barrel ageing

ESI-MS of Cucurbituril Complexes Under Negative Polarity

Electrospray ionization mass spectrometry (ESI-MS) is a powerful tool to study host-guest supramolecular interactions. ESI-MS can be used for detailed gas-phase reactivity studies, to clarify the structure, or simply to verify the formation of complexes. Depending on the structure of the host and of the guest, negative and/or positive ESI are used. Here we report the unexpected formation of host-guest complexes between cucurbit[n]urils (n = 7, 8, CB[n]) and amine, styryl pyridine, and styryl pyridine dimer cations, under negative ESI. Non-complexed CB[n] form double charged halide (Br-, Cl-, F-) adducts. Under negative ESI, halide ions interact with CB[n] outer surface hydrogen atoms. One to one host-guest complexes (1:1) of CB[n] with positive charged guests were also observed as single and double charged ions under negative ESI. The positive charge of guests is neutralized by ion-pairing with halide anions. Depending on the number of positive charges guests retain in the gas phase, one or two additional halide ions are required for neutralization. Complexes 1:2 of CB[8] with styryl pyridines retain two halide ions in the gas phase, one per guest. Styryl pyridine dimers form 1:1 complexes possessing a single extra halide ion and therefore a single positive charge. Negative ESI is sensitive to small structural differences between complexes, distinguishing between 1:2 complexes of styryl pyridine-CB[8] and corresponding 1:1 complexes with the dimer. Negative ESI gives simpler spectra than positive ESI and allows the determination of guest charge state of CB[n] complexes in the gas phase