Profiling of grape monoterpene glycosides (aroma precursors) by ultra-high performanceliquid chromatography-high resolution mass spectrometry (UHPLC/QTOF)

A ‘suspect screening analysis’ method for grape metabolomics by ultra-high performance-liquid chromatography (UHPLC) and highresolution\r\nquadrupole-time of flight (QTOF) mass spectrometry was recently developed. This method was applied to study grape\r\nmonoterpene glycosides, the main grape aroma precursors. Since standard compounds were not available, they were tentatively\r\nidentified by overlapping various analytical approaches, in agreement with the indications recommended in mass spectrometry\r\n(MS)-based metabolomics. Accurate mass and isotopic pattern, MS/MS fragmentation, correlation between fragments observed\r\nand putative structures and between liquid chromatography coupled with mass spectrometry (LC/MS) and gas chromatography/\r\nmass spectrometry signals were studied. Seventeen monoterpene glycosides were identified without performing the hydrolytic artifacts\r\ncommonly used to study these compounds whichmay affect sample profile. This is the first time that a detailed study of these\r\naroma precursors has been carried out by direct LC/MS analysis.