Structures of polymeric pigments in red wine and their derived quantification markers revealed by high‐resolution quadrupole time‐of‐flight mass spectrometry

Abstract

The quantification of polymeric pigment families in red wine through their derived quantification markers released during phloroglucinolysis will allow the understanding of their formation kinetics and evolutions during aging which has not been achieved until now and is in urgent need. The identification of these quantification markers was achieved by high-resolution mass spectrometry (HRMS) in this study. HRMS was used to clarify the fragmentation patterns in positive mode of polymeric pigments and identify their derived quantification markers released during phloroglucinolysis. With HRMS, identification of (epi)catechin-malvidin-3-O-glucoside adducts was simplified to MS/MS, and the fragmentation pattern of malvidin-3-O-glucoside-(epi)catechin adducts was clearly demonstrated. The attribution of four detected ions at m/z 1071.2765 in red wine to the trimeric structure of (epi)catechin-[malvidin-3-O-glucoside-A type linkage-(epi)catechin] and [malvidin-3-O-glucoside-A type linkage-(epi)catechin]-(epi)catechin was achieved for the first time by MS/MS and evidence given by phloroglucinolysis. Moreover, four kinds of derived quantification markers released from polymeric pigments during phloroglucinolysis were also identified. The fragmentation pathways of polymeric pigments in red wine and their derived quantification markers released during acidic chemical depolymerisation were clarified which will allow their quantification in red wine.