As one class of secondary metabolites, carotenoids in aleurone of
wheat, oat, corn and embryo of barley are of significantly higher
levels (Ndolo and Beta, 2013) while phenolic acids are mainly present
in the bran layers of rice (Zhou et al., 2004; Zhang et al., 2010)
existing as free, conjugated, and bound forms. In wild rice, some
phenolic acids, such as diferulic acid and disinapic acid are even