Widely Targeted Metabonomic Analysis to Study Effect of GSH on Metabolites of Chardonnay Wine during Simulated Oxidation

The effects of reduced glutathione (GSH) on non-volatile and volatile metabolites of Chardonnay wine during storage under simulated oxidation were investigated. The metabolites of GSH, which play a key role in the storage of white wine, were identified. In this study, GSHs at 0, 10, and 20 mg/L were added to wine samples and stored at 45 °C for 45 days. Wine samples supplemented with 0 mg/L GSH were used as controls (CK). The samples stored for 45 days were analyzed via ultra-high performance liquid chromatography–tandem mass spectrometry and gas chromatography–tandem mass spectrometry. A total of 1107 non-volatile metabolites were detected, and 617 volatile metabolites were identified. Variable Importance in Projection (VIP) of >1.0 and Fold Change (FC) of ≧2.0 were used to screen differential metabolites. A total of 59 important non-volatile and 39 differential volatile metabolites were screened. Among the non-volatile metabolites, 17 substances were down-regulated, whereas 16 substances were up-regulated. Among the volatile metabolites, 3 substances were down-regulated, while 19 substances were up-regulated. After analysis, some lipids were found to play an important role in the changes to non-volatile substances. This study provides theoretical support for further application of GSH in increasing the oxidation stability of white wine.