Ester-Linked Phenolic Components of Carrot Cell Walls

The cold alkali-labile cell wall phenolics of carrot storage roots have been examined by diode-array HPLC following sequential treatment of purified wall material with aqueous sodium hydroxide of increasing strength. In addition to 4-hydroxybenzoic acid and ferulic acid, which have previously been reported from this source, a range of other typical wall-bound phenolic aldehydes and cinnamic acid derivatives were also identified. An 8- O -4‘-linked dehydrodiferulic acid, which has recently also been identified as a major ferulic acid dimer in several monocots, was found to be present in readily measurable quantities, and other putative dimers were also noted. At least ca. 30% of the total ferulic acid existed in dimer form. Cell wall phenolics might have a role to play in influencing the physical properties of carrot tissue. Keywords: Carrot; cell wall; Daucus carota; dehydrodiferulic acid; phenolics