**4.1. White maize grain**

In white maize grain, differences in total phenolic content (solubles + insolubles) due to grain hardness are present. These differences are supported by the role of ferulic acid to provide strength to the cell wall of different grain structures. But also, each botanical grain structure has a content and a particularly phenolic profile, which is associated with its functionality.


FP: free phenolics; SGP: soluble glycosylated phenolics; SEP: soluble esterified phenolics; IP: insoluble phenolics; TP: total phenolics; GAE: gallic acid equivalents; DW: dry weight.

**Table 2.** Contents of soluble and insoluble phenolic compounds in maize grain with different colors.
