In this study, the antioxidative/reducing activity of buckwheat-enhanced dark wheat breads (BEDWBs), based on the substitution of dark wheat flour (DWF) with buckwheat flour (BF) or flour from roasted buckwheat groats (BFR) at levels of 10, 20, 30 and 50% (w/w), was investigated. The antioxidative activity was measured against the 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS•+), the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) and the superoxide anion radical (O2−•) by photochemiluminescence (PCL), reducing power by Fe(III) reduction and directly by cyclic voltammetry (CV) technique. The Fe(II) chelating capacity was also provided. The substitution of dark wheat bread with white and roasted buckwheat flour up to 50% (w/w) resulted in higher scavenging capacity against free radicals. The chelating and reducing power were above threefold higher as compared to a reference dark wheat bread. The improved antioxidant properties of buckwheat-enhanced dark wheat breads were due to the incorporation of buckwheat flour polyphenols. The high correlation noted between the total phenolic content and antioxidant capacity suggested that these assays may be used to characterize the cereal products enriched by buckwheat flours. Overall, buckwheat-enhanced dark wheat bread could be applied as food with more efficient antioxidant properties.
Part of the book: Superfood and Functional Food