Introduction

White and rosé winemaking requires particular attention to the risks associated with the oxidation phenomena. Colour and aroma are key determinants of wine quality and freshness for these wines and oxidative stability is therefore at the heart of winemakers’ concerns, especially given the current trend to limit chemical inputs, particularly sulphites.

In this context, research is leading to a better understanding of wine oxidation mechanisms and the development of new tools aiming at improving the longevity of wines during aging and storage in the cellar and beyond after bottling.

Research work carried out at the IUVV (Institut Universitaire de la Vigne et du Vin) have allowed the detailed characterisation of a new inactivated yeast with guaranteed glutathione content that is unique and effective in relation to the oxidative stability of wine.

Abstract

This results from the application of an optimised production process to a single strain of Saccharomyces cerevisiae yeast to maximise the biosynthesis and accumulation of intracellular glutathione and other compounds of interest.

Non-targeted metabolomics characterisation has demonstrated the unique composition of the new inactivated yeast and its impact on wine compared with other inactivated yeasts. In addition to its high content in reduced glutathione, the presence of other reducing peptides further increases the positive impact of this specific inactivated yeast on the oxidative stability of wine.

Numerous application trials have been carried out on white and rosé vinifications during the 2017 and 2018 vintages, and the resultpublication winemak-in Glustatars show that early treatment before fermentation (after pressing, during clarification or in pre-fermentation cold storage) with the specific inactivated yeast allows for better preservation of aromatic compounds and colour, as well as increased antiradical activity in wines up to bottling.

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