italianoenglishfrançaisdeutschespañolportuguês
Language
Search
  • » Infowine Premium
  • » First characterization of thiol precursors in Colombard and Gros Manseng: comparison of two cultivation practices
  • The Future of Oenological Webinars
    Let's Create Together the Most Interesting Content for the Industry!
    We are excited to involve you in the process of creating our oenological content! Your feedback is essential to providing you with articles, webinars and trainings that are truly useful for you and...
    Published on: 01/31/2024

First characterization of thiol precursors in Colombard and Gros Manseng: comparison of two cultivation practices

Gabriel Dournes et al. | Univ Montpellier | INRAE | Institut Agro - France

Organic production of wine in the past years has known an important augmentation. This type of cultivation practice switches synthetic phytosanitary product for copper-based protection as fungicide. While the effect of copper on soil and vine is understood, few data are published concerning its impact on wine aromas and even less concerning varietal thiol. The aim of this work was to characterize the thiol aromatic potential of Colombard and Gros Manseng grapes and to investigate the effect of copper on thiol precursor biogenesis.

30 parcels were selected (15 conventional and 15 organic) with sampling at harvest for 18 of them and 3 sampling dates during ripening for the other 12 parcels. Chemical analyses of thiol precursors were performed by adapting an UPLC-MS/MS method based upon Stable Isotope Dilution Assay.

With this first characterization, it was demonstrated that both varieties presented concentrations of glutathionylated (G3SH) and cysteinylated (Cys3SH) precursors of 3-sulfanylhexan-1-ol up to 454 µg/kg and 21 µg/kg respectively. No precursors of the 4-sulfanyl-4-methylpentan-2-one were detected. So, Colombard and Gros Manseng were ranked in the top of varietal thiol producers with Sauvignon and Pinot Gris grapes (Pena-Gallego et al. 2012).

By comparing the copper protected parcels to the others, a significant decrease was identified (p-value = 0.01) of G3SH content in organic Gros Manseng grapes which was around 30%. This could represent a loss in 3SH of 1000 ng/kg in finished wines if a conversion rate of 3% between G3SH and 3SH was considered. On the opposite, Colombard grapes remained unaffected by the copper spraying with no effect on the precursors content at harvest.

The accumulation kinetics of thiol precursors under the two protection methods (copper or not) was also analysed. No accumulation of thiol precursors between seven days prior and after the harvest was observed in Colombard grapes which was inconsistent with literature on other grape varieties such as Sauvignon B. or Melon B.. Gros Manseng grapes showed significant accumulation for conventional culture (161 µg/kg to 356 µg/kg) over the two last weeks of ripening. Furthermore, copper treated parcels of Gros Manseng had no accumulation through the two-week study. However, Pearson test did not show a direct correlation between copper content and G3SH suggesting a possible interaction of copper with thiol precursors making them not analyzable under our conditions or a modification of vine metabolism.

For the first time two grapes varieties (Colombard and Gros Manseng) were characterised, varieties that have high potential towards varietal thiols such as Sauvignon. A negative copper effect was identified on Gros Manseng variety for both precursors content at harvest and accumulation kinetics while Colombard remained unaffected.

Video of the seminar held during Macrowine virtual (June 23-30, 2021)

Annual subscription to Infowine: The subscription, at a cost of € 60 (VAT included) entitles you to one year's access to all the documents published on the site, including the historical archive (click here).

Published on 10/18/2022
Pictures
Premium Contents Area
  • First characterization of thiol precursors in Colombard and Gros Manseng: comparison of two cultivation practices
Price:27 €(Tax included)
Related sheets
    Low intervention?
    Infowine Focus
    Wine is fundamentally a high-intervention product, and along all stages from harvest to bottling it's our job to guarantee safety and quality, but it's also up to us to research, experiment, and ad...
    Published on:01/02/2023
    Diversity in winemaking
    Infowine Focus
    Producing a wine according to our oenological objective, wanting to express the variety, but adapting practices according to the sanitary status of the grapes, is continuous experimentation. We aga...
    Published on:09/28/2022
    Sensory characterisation of grapes and yeast strains
    Infowine Focus
    Phenolic composition of grapes has an important impact on the final intrinsic quality of (red) wines. Wine taste, mouthfeel and colour are driven principally by phenolic compounds present in grapes...
    Published on:08/29/2022
    Sparkling wines
    Infowine Focus
    For the production of quality sparkling wines, it is important to ensure the separation of the correct phenolic profiles of must fractions. Find out how UV-Visible spectroscopy, together with chemo...
    Published on:08/17/2022
    The aroma and taste of wine
    Infowine Focus
    Chemical, biochemical and physiological factors influence the composition of the retronasal aroma during wine consumption, but not only tannins influence mouthfeel: anthocyanins do too. New methods...
    Published on:01/05/2022
    Improve, enhance and modulate aromatic evolution
    Infowine Focus
    What's the importance of varietal thiols, esters and glycerol content from an organoleptic quality point of view? How do volatile compounds evolve during wine aging and storage conditions? Are ther...
    Published on:12/28/2021
© All Right Reserved
ISSN 1826-1590 VAT: IT01286830334
powered by Infonet Srl Piacenza
- A +
ExecTime : 1,609375