Characterization of phenolic acids in black carrots (Daucus carota ssp sativus var. atrorubens Alef.) by high-performance liquid chromatography/electrospray ionization mass spectrometry

Phenolic acids were extracted from black carrot roots (Daucus carota ssp. sativus var. atrorubens Alef.) and a black carrot juice concentrate, and characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry. Most of the compounds detected were identified as depsides composed of p-coumaric, caffeic and ferulic acids. Additionally, three hydroxybenzoic acid derivatives and one quercetin glycoside were detected. 5-0-Caffeoylquinic acid (chlorogenic acid) represented the predominant compound amounting to 657mg/kg in the roots and 5815mg/kg in the concentrate. The specific fragmentation patterns of mono- and dihydroxycinnamoylquinic acids allowed the distinction of several stereoisomers. The presence of 4-O-caffeoylquinic acid and several further hydroxycinnamic acid esters, together with compounds not belonging to the depside type, is reported for the first time. The present study reveals that the phenolic profile of black carrots is even more complex than hitherto assumed and may contribute to pigment stability of extracts derived from the roots. Copyright (C) 2004 John Wiley Sons, Ltd.