DEVINE

This research aims to better understand and control the microbiological and physicochemical processes involved in the aging of vin jaune under flor, in order to ensure the quality and typicity of this emblematic product of the Jura. It contributes to the economic, cultural, and environmental sustainability of the wine industry in the Bourgogne-Franche-Comté region. Research on yeast film growth in wine has so far relied mainly on targeted approaches, focusing on specific factors such as assimilable nitrogen or ethanol. While informative, these studies fail to capture the multifactorial impact of the wine matrix. The complex interactions among phenolics, minerals, dissolved oxygen, sugars, and other metabolites remain largely unexplored.

The project aims to address this gap through an integrated strategy. First, non-targeted metabolomics using high-resolution mass spectrometry (HRMS) will be applied to a wide range of flor wines, providing for the first time a comprehensive chemical fingerprint and its evolution during ageing. These metabolites reflect both the physiological state of Saccharomyces cerevisiae strains and the environmental conditions they experience. By comparing metabolic profiles across strains inoculated as biofilms in diverse wine matrices, we will identify markers associated with faster and more stable film formation. To complement this, biofilm development will be characterized by Confocal Light-Scanning Microscopy (CLSM) and Dynamic Full-Field Optical Coherence Tomography (D-FF-OCT), enabling in situ imaging of biofilm architecture. This approach will allow us to explore how thickness and structural heterogeneity relate to metabolic activity, providing insights into intra-biofilm differences in metabolite production.

Analytical tools such as Fourier Transform Infrared spectroscopy (FTIR) will characterize the matrices, while both targeted and untargeted metabolomic analyses will be carried out at different stages of ageing. Statistical methods will be used to link metabolite patterns, matrix composition, and yeast performance.

The ultimate goal is to pinpoint the factors, or combinations of factors, that most strongly drive yeast growth and biofilm formation, as well as the matrix traits correlated with these processes. By integrating metabolomics, OCT microscopy and statistical modelling, this project will provide new insights into the determinants of velum yeast development and the multifactorial influence of the wine matrix.