High-throughput LC-MS/MS discrimination of musts and wines contaminated by fresh mushroom off-flavor on the basis of reliable and easily quantifiable analytical markers: 1-hydroxyoctan-3-one and its derivate octane-1,3-diol

Since the 2000's, the development of fresh mushroom off-flavor (FMOff) in wines has been a recurring problem stemming from fungal alteration on grapes. Known mushroom flavors like 1-octen-3-one do not fully explain this defect appearance during winemaking. This study aimed to identify relevant analytical markers in musts and wines to early classify the quality of these oenological matrices. Musts made with grapes naturally affected by grey mold as an apparent alteration and their corresponding wines were analyzed by LC-MS/MS. Two compounds were identified and correlated well with the development of FMOff in wines: 1-hydroxyoctan-3-one and octane-1,3-diol. The latter was identified for the first time in oenological matrices and could be derived from 1hydroxyoctan-3-one through yeast metabolism. Both markers enabled the formal discrimination of musts with FMOff potential and FMOff wines from control samples. This provides a fast and reliable diagnostic tool for winemakers.