Distribution of insoluble bound phenolic acids in barley grain

Abstract

Insoluble bound phenolic acids were analysed by g.l.c. and by h.p.l.c. in eight abraded fractions of barley grain. Vanillic, p‐coumaric, ferulic and diferulic acids were identified in all the fractions. Ferulic and p‐coumaric acids were quantitatively the most important. The outer layers, comprising husks, pericarp, testa and aleurone cells, contained the highest concentrations of total phenolic acids (0.6–0.9%) while their concentrations were considerably lower in the endosperm layers (0.1% or less). Calculated on the basis of the cell wall content in the fractions, the highest concentration of ferulic acid was found in fractions enriched with aleurone cells while the highest concentration of p‐coumaric acid was found in fractions containing high levels of husks.