Hydroxycinnamic acids, sugar composition and antioxidant capacity of arabinoxylans extracted from different maize fiber sources

Hydroxycinnamic acids, sugar composition, total phenolics and antioxidant capacity of arabinoxylans (AX) from maize fiber (MF), insect-resistant maize pericarp (RP), insect-susceptible maize pericarp (SP) and nejayote (N) were assessed through HPLC-RI, Folin–Ciocalteau and ORAC assays, respectively. No significant difference existed in Arabinose/Xylose ratio among the different fiber sources. The antioxidant capacity of AX was highly correlated with total phenolic (r = 0.93), dehydrotriferulic acid (tri-FA) (r = 0.96) and p-coumaric acid (p-CA) (r = 0.94) concentrations. The hydroxycinnamic acids profile of AX varied according to the maize fiber source and extractions conditions. The AX extracted from RP (RPAX) contained the highest amount of hydroxycinnamic acids and exerted the highest antioxidant capacity. Regarding to ferulic acid (FA) and dehydrodiferulic acid (di-FA) amounts, the AX extracted from SP (SPAX) ranked second, followed by the NAX and MFAX samples whereas the MFAX was second in terms of tri-FA and p-CA.