Varietal thiol management during the winemaking process

Remi Schneider, Oenobrands Product & Application Manager

Varietal thiol management during the winemaking process

The varietal thiols (4-mercapto-4-methylpentan-2-one (4MMP), 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexylacetate (A3MH) are key odorants of wine.

They are released during the alcoholic fermentation from precursors present in grapes. Different biogenetic pathways have been reported for their.

The first two pathways involved cysteinylated and glutathionylated S-conjugates, cleaved by the yeast β-lyase activity. A third pathway has been also identified involving (E)-2-hexenal and (E)-2-hexenol, even if the sulfur donor hasn’t been yet identified. Recently, some new derivatives (aldehyde forms, SO2-combined forms, glutathione derivatives) have been pointed out. The 3MH levels originating from those pathways could explain from up to 60% of the wine 3MH. Thus a large field of investigation is opened to better understand its biogenesis.

Some viticulture techniques favored thiols precursors accumulation in grapes or musts, such as the vine water status and the nitrogen fertilization management (soil fertilizer or foliar spraying), or the oxidation mechanisms during must elaboration.

However, fermentation conditions hugely influence the thiols release: yeast strain, temperature, nitrogen nutrition. Surprisingly, few studies were dedicated to the thiol precursors transport into the yeast.

The General Amino acid Permease 1 (GAP1) is known to be the main transport system for cysteinylated precursors. Its regulation by the ammonium levels in must explain that the yeast nutrient composition (NH4+ / amino acids ration) and time of addition are two key parameters. For glutathionylated precursors transport into the yeast cell, a recent study showed the importance of Opt1 transporters.

The reports reproduced in these films were presented at the 11th edition of Enoforum (Zaragoza, 31 May-1 June 2018) within the module organized in cooperation with Oenobrands

Published on 06/12/2019
Item available in spagnolo
    • Varietal thiol management during the winemaking process
    • fjrigjwwe9r1video:descrizione
      Remi Schneider, Oenobrands Product & Application Manager
Related sheets
    Malolactic fermentation: knowledge versus practice
    Maret Du Toit, Stellenbosch University - Elda Lerm, Anchor Yeast
    The knowledge, objectives and management of malolactic fermentation (MLF) have evolved greatly in recent years. Until very recently, Oenococus oeni was the main microorganism responsible and its on...
    Published on:07/23/2020
    Emerging non-thermal technologies applied to winemaking
    Antonio MORATA, Universidad Politécnica de Madrid, Spain
    In the keynote speech given at Enoforum 2022, Antonio Morata talked about emerging non-thermal technologies applied to oenology and their impact on the extraction of phenolic compounds from grapes,...
    Price:27 €(Tax included)
    Published on:09/20/2022
    All acids are equal, but some are more equal than others: (BIO)ACIDIFICATION OF WINES
    Hranilovic A. et al., ISVV, University of Bordeaux (France) | The University of Adelaide (Australia)
    Interesting and sustainable oenological solution to combat the lack of acidity in wines and microbial threats: bio- acidification with some strains of Lachancea thermotolerans through the productio...
    Published on:07/13/2022
    Formation of volatile sulphur compounds during fermentation
    R. Jiménez Lorenzo et al., INRA, Université Montpellier, SupAgro
    Among the thousands of molecules comprising the wine aroma, sulfur-containing compounds can be considered as a “double-edged sword”: some of them, deriving from varietal precursors provide fruity p...
    Published on:06/14/2022
    Adaptation of Lactobacilli towards low pH and SO<sub>2</sub> to develop MLF in base musts for sparkling wines
    Sergi Ferrer, ENOLAB (BioTecMed) University of Valencia - Spain
    This work aimed to grow some selected strains of Lactobacillus in grape juice and perform early MLF. With this strategy, beyond performing the MLF homolactic bacteria can contribute clearly to main...
    Price:27 €(Tax included)
    Published on:05/24/2022
    (Bio)acidification of wines
    Dr Ana Hranilovic, University of Adelaide - Australia
    Interesting and sustainable oenological solution to combat the lack of acidity in wines and microbial threats
    Price:27 €(Tax included)
    Published on:04/27/2022
© All Right Reserved
ISSN 1826-1590 VAT: IT01286830334
powered by Infonet Srl Piacenza
- A +
ExecTime : 2,53125