*3.2.2. p‐coumaric acid*

After ferulic acid, the second most abundant phenolic compound in maize grain is p‐cou‐ maric acid. It is present in both forms, the soluble phenolic fraction and the insoluble, with greater presence in the latter. In the insoluble fraction it is mainly linked to lignin, and to a lesser extent to polysaccharides embedded in the cell wall [28]. In the soluble fraction of purple maize the value reported for this acid is 34.1 mg/100 g DW, and for the phenolic insol‐ uble fraction is 573.4 mg/100 g DW. Surprisingly, ferulic acid values reported in the insoluble fraction of this maize were significantly lower (154.2 mg/100 g DW) compared to the amount of p‐coumaric acid [29].
