Effects of oak barrel aging monitored by 1H-NMR metabolomics

Abstract

The study of wine evolution during barrel aging is an important aspect of wine quality. Our previous works have shown that wine metabolome monitoring by

1H-NMR approaches allows determining the impact of different winemaking processes including traitements using enzymes or finning agents [1]. In this study, the effects of oak barrel aging were investigated by 1H-NMR metabolomics. Targeted and untargeted 1H-NMR analyses were performed on wines conserved in barrels provided by four different barrel manufacturers. Wine samples were taken after one and twelve months. The collected data were statistically processed by principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and partial orthogonal least squares discriminant analysis (OPLS-DA). Cross permutation tests and ANOVA were performed to validate the results and determine the compounds significantly impacted. The results of chemometrics analyses show the relevance of 1H-NMR metabolomics for studying the impact of oak barrel aging. The targeted analysis allowed us to identify the compounds that evolved during barrel aging. The untargeted analysis proved to be particularly interesting for the study of the specific signature of each barrel makers. 1H-NMR metabolomics is a rapid method that could be used as a decision support tool for winemaking.