OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 OENO IVAS 9 OENO IVAS 2019 9 Chemical and Biochemical reactions, including grape and wines microorganisms impact 9 When organic chemistry contributes to the understanding of metabolism mechanisms

When organic chemistry contributes to the understanding of metabolism mechanisms

Abstract

Many compounds of interest in wine are difficult to analyze since they are present in very small quantities or they are unstable. The need for reliable data led scientists to develop complex method in order to overcome the analytical difficulties and provide accurate quantitative data for grape or wine characterization.

For 10 years, we developed several chemical strategies to obtain analytical standards either as labelled analogues or as diastereomers to develop SIDA and DIDA analytical methods, respectively. These quantification methods afforded accurate and reliable results by suppressing analytical bias due to sample preparation. Several examples will be presented from deuterated analogues: varietal thiols [1], thiol precursors [2], Ochratoxin A [3], and diastereoisomers: Ochratoxin A [4] and hydroxycinnamic acids [5].

Another interesting application based on synthetic compounds lies in their possible exploitation as tracers. Indeed, the scale-up and optimization of chemical syntheses from μg to mg levels provided us with substantial amounts of molecules that could be used in metabolism studies. For example, we recently used labelled thiol precursors as tracers in Sauvignon Blanc musts for metabolism studies. Degradation of such tracers was monitored to highlight several key interconversion mechanisms and bring new elements in varietal thiol biogenesis knowledge [6]. In these applications, the choice of the labelling position (for Ochratoxin A for instance) or multilabelling possibilies (for thiol precursors) offer future opportunity to investigate detoxification process or to obtain insight in the metabolism of aroma precursors, respectively.

References

1. a) A. Roland, R. Schneider, A. Razungles and F. Cavelier, Varietal thiols in wine: Discovery, Synthesis and Applications, Chem. Rev. 2011, 111, 7355. b) R. Schneider, Y. Kotseridis, J.-L. Ray, C. Augier and R.Baumes, Quantitative determination of sulfur-containing wine odorants at sub parts per billion levels.
2. Development and application of a stable isotope dilution assay, J. Agri. Food Chem., 2003, 51, 3243. 2. H.Bonnaffoux, A.Roland, E.Rémond, S.Delpech, R.Schneider, F.Cavelier, First identification and quantification of S-3- (hexan-1-ol)-γ-glutamyl-cysteine in grape must as a potential thiol precursor, using UPLC-MS/MS analysis and stable iso-tope dilution assay, Food Chem., 2017, 237, 877.
3. A.Bouisseau, A.Roland, R.Schneider and F.Cavelier, First Synthesis of a Stable Isotope of Ochratoxin A Metabolite for a Reliable Detoxification Monitoring, Org. Lett., 2013, 15, 3888.
4. A.Roland, P.Bros, A.Bouisseau, F.Cavelier and R.Schneider, Analysis of Ochratoxin A in musts and wines by LCMS/MS: Comparison of Stable Isotope Dilution Assay and Diastereomeric Dilution Assay Methods, Anal. Chim. Acta, 2014, 818, 39.
5. F. Cavelier, A. Roland, A. Bouisseau, J. Martinez, R. Schneider. Method for the esterification of polar molecules, WO 2015 011230
6. H. Bonnaffoux, S. Delpech, E. Rémond, R. Schneider, A. Roland, F. Cavelier, Revisiting the evaluation strategy of varietal thiol biogenesis, Food Chem., 2018, 268, 126.

DOI:

Publication date: June 19, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Florine Cavelier Hugo Bonnaffoux, Anaïs Bouisseau, Stéphane Delpech, Aurélie Roland, Rémi Schneider

Université de Montpellier (France)

Contact the author

Keywords

organic chemistry, analytical chemistry, internal standards, aroma

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

INFLUENCE OF THE NITROGEN / LIPIDS RATIO OF MUSTS ON THE REVELATION OF AROMATIC COMPOUNDS IN SAUVIGNON BLANC WINE

Production of volatile compounds by yeast is known to be modulated by must nitrogen. Nevertheless, various parameter of must quality have an impact on yeast fermentation. In this study we propose to evaluate the impact of nitrogen / lipids balance on a Sauvignon Blanc grape juice (Val de Loire).
Must was prepared from the same grapes at pilot scale. Three modalities were carried out: direct pressing, direct pressing with a pre-fermentation cold stabulation and pellicular maceration before pressing.

Read More

Exploring the mechanisms underpinning grapevine susceptibility to esca in a range of Vitis vinifera L. cultivars

Grapevine susceptibility to fungal diseases, including the vascular disease esca, is a major threat for wine productivity and vineyard perennity worldwide.

Read More

The key role of vineyard parcel in modifying flavor compounds of Cabernet Sauvignon grapes

To produce premium wines in a specific region is the goal of local oenologists. This study aimed to investigate the influence of soil properties on the flavoromics of Cabernet Sauvignon grapes to provide a better insight into single-vineyard wines. Six commercial Cabernet Sauvignon vineyards were selected in the Manas region to collect berries at three harvest ripeness in three seasons (2019–2021). The six vineyards had little difference in mesoclimate conditions while varying greatly in soil composition.

Read More

The application of soil biological indicators to support soil conservation practices and landscape quality in viticulture

Le but de notre travail a été d’étudier l’influence de différents systèmes de la gestion du sol en viticulture sur des paramètres biologiques de sol comme indicateurs de la protection et de la qualité du sol. La conservation de sol est indispensable pour une viticulture durable et la protection du terroir. Nos résultats ont montré, que la matière

Read More

Effect of partial net shading on the temperature and radiation in the grapevine canopy, consequences on the grape quality of cv. Gros Manseng in PDO Pacherenc-du-vic-Bilh

As elsewhere, southwestern France vineyards face more recurrent summer heat waves these last years. Among the possibilities of adaptation to this climate changing parameter, the use of net shading is a technique that allow for limiting canopy exposure to radiations. In this trial, we tested net shading installed on one face of the canopy, on a north-south row-oriented plot of cv. Gros Manseng trained on VSP system in the PDO Pacherenc-du-Vic-Bilh. The purpose was to characterize the effects on the ambient canopy temperatures and radiations during the season and to observe the consequences on the composition of grapes and wines. Two sorts of net were used with two levels of obstruction (50% and 75%) of the photosynthesis active radiation (PAR). They have been installed on the west side of the canopy and compared to a netless control. Temperature and PAR sensors registered hourly data during the season. On specific summer day (hot and sunny) manual measurements took also place on bunches (temperature) and in different spots of the canopy (PAR). The results showed that, on clear days, the radiation is lowered by the shade nets respecting the supplier criteria. The effects on the ambient canopy temperature were inconstant on this plot when we observed the data from the global period of shading between fruit set and harvest. However, during hot days (>30°C), the temperature in the canopy was reduced during afternoon and the temperature of the bunch surface was reduced as well comparing to the control. A decrease of the maturity parameters of the berries, sugar and acidity, was also observed. Concerning the wine aromatic potential, no differences clearly appeared.

Read More