Effect of water-extractable arabinoxylans from wheat aleurone and bran on lipid peroxidation and factors influencing their antioxidant capacity

- Arabinoxylans (AX) were extracted from wheat aleurone and bran.
- AX chemical composition and structure was characterized.
- Effect of AX on lipid peroxidation was demonstrated.
- Antioxidant activity is influenced by the ferulic acid content of AX.

Dietary lipid hydroperoxides (LOOH) are implicated in the rise of colon cancers. We investigated the effect of water-extractable arabinoxylans (WEAX) on lipid peroxidation under simulated gastric conditions. Water-extractable fractions containing mostly arabinoxylans were isolated from wheat aleurone and wheat bran and fractionated by stepwise precipitation with (NH4)2SO4 at 50% and 75% saturation. LOOH concentration (121.2±3.8 µM/g) of grilled chicken breast muscle increased by 30%; however, it remained unaltered or decreased (≤35%) depending on type and concentration of WEAX fractions. Antioxidant capacity of WEAX fractions based on DPPH, ABTS and ORAC was 28.2 - 147.9, 91.2 - 355.3, and 185.9 - 527.5 µM TE/g, respectively. The content of ferulic acid residues in WEAX fractions (R =0.99) and relative proportions of monosubstituted xylose residues (R =0.80) influenced the antioxidant capacity. Consumption of diets rich in feruloylated WEAX may offer protection against oxidative damage in the gastrointestinal tract.