Effect of iron-enrichment on the antioxidant properties of wheat flour and bread

Abstract

The enrichment of wheat flour with iron attracted notable attention in some countries in order to prevent anaemia. For the first time, the current study was aimed to investigate the effects of iron enrichment on change trend of the antioxidant compounds and total antioxidant capacity (TAC) of wheat flour during storage and bread baking. In this regard, the Folin–Ciocalteu and aluminium chloride methods were used to measure the phenolic acid and flavonoid concentrations, respectively. Also, the TAC was evaluated by using the DPPH and FRAP methods. According to results, during storage, no significant change in the concentrations of flavonoid and phenolic acid in the unenriched and iron-enriched flour samples was observed. However, TAC reduction of the iron-enriched flour samples was higher than that of the iron-unenriched samples. Moreover, no change in antioxidant attributes as a result of fermentation was noted. There was a decline in levels of phenolic acid, flavonoid, and TAC during bread baking, while in the iron-enriched samples, the observed decrease was more pronounced probably due to further losses in reducing the power of antioxidant components as well as pro-oxidant properties of iron. Obtained findings could be useful for making decisions on the continuation of iron enrichment.