To accomplish this, the aqueous and alcohol soluble fractions as well as the lipid components of wheat bran were firstly removed and the
freeze-dried insoluble residue was then treated with different concentrations of green tea infusions or aqueous
solutions of epicatechin (EC) and epigallocatechin-3-gallate (EGCG) for certain time. Treatment with EC
(0–200 μM) had no significant effect on the antioxidant capacity of insoluble bran fraction. However, treatment
with EGCG significantly (p b 0.05) increased linearly the antioxidant capacity as a function of concentration
(0–100 μM). Treatmentwith great tea infusions (1–3 g/100 ml) also increased the resulting antioxidant capacity
of insoluble bran fraction, but the effect was lesser at higher infusion concentrations. Liquid chromatography couple
to mass spectrometry (LC–MS) analyses of aqueous phases after treatment indicated comparable levels of decrease
in the concentrations of catechins confirming their reaction with the radical forms of antioxidants bound
to insoluble bran matrix.