Monitoring red wine maturation in oak barrels using 1H NMR-based metabolomics

Wine maturation in oak barrels is a well-known winemaking practice that, among other things, brings roundness and complexity to wine. Studying wine evolution during barrel maturation is crucial to ensure wine quality. Red wines produced in a wine growing estate of the Bordeaux region were monitored after one and twelve months of maturation in oak barrels in the estate’s cellar. Wines were kept in oak casks from three different manufacturers. The evolution of the wine constituents during maturation was monitored by 1H NMR-based metabolomics combined with multivariate statistical analysis. NMR spectra were submitted to targeted and untargeted approaches. The wine maturation effects were thereby monitored and the discriminant metabolites identified. The wines analysed after one month of maturation exhibit higher contents of amino acids, catechin and epicatechin, acetoin and choline than the wines analysed twelve months after maturation; for their part, the latter wines showed higher contents of acetic acid, ethyl lactate, arabinose and glucose. In addition, significant differences were observed between the wines depending on the barrel manufacturers.