Quantification of three galloylglucoside flavour precursors by liquid chromatography tandem mass spectrometry in brandies aged in oak wood barrels

Vanillin-(6'-0-galloy1)-beta-glucopyranoside (VGG), 3,4,5-trimethoxyphenyl-(6'-0-galloy1)-beta-glucopyranoside (TMPGG), and (6R,9R)-3-oxo-alpha-iono1-9-0-(6'-0-galloy1)-beta-glucopyranoside (macarangioside E) were identified as aroma precursors in oak wood.An LC-MS/MS method was developed and validated to quantify these three galloylglucoside compounds in brandies aged in oak barrels. The detection system consisted of a triple quadrupole mass analyser operating in multiple reaction monitoring (MRM) mode. For the first time, vanillin-beta-Dxylopyranoside (VX) was synthesised for use as an internal standard. The detection limits (48 p,g L-1 for VGG, 52 mu g L-1 for TMPGG, and 19 mu g L-1 for macarangioside E) were low enough to quantify these aroma precursors in spirits without any sample preparation. (C) 2016 Elsevier B.V. All rights reserved.