Dephytinisation Of Sangak And Barbari Bread Made From Different Extraction Rate Flours Increases Iron And Zinc Bioaccessibility In Caco-2 Cells

Bread is a staple food in many countries and an important source of iron and zinc. The bioavailability of these minerals is generally low because of the content of phytic acid. Traditional Iranian breads were prepared with flours of different extraction rates, Sangak at 93% and Barbari at 82%. Breads were dephytinised by addition of Aspergillus niger phytase during in vitro digestion. The effect upon iron and zinc bioaccessibility in the Caco-2 cell model was investigated. The cellular uptake of iron and zinc was lower from Sangak, compared to Barbari, despite higher mineral content in Sangak. Dephytinisation of both breads increased iron uptake in the Caco-2 cells (0.65 vs. 1.64 in Sangak and 0.77 vs. 1.97 ng mg-1 protein in Barbari). Zinc uptake increased from 0.98 to 2.8 in Sangak and from 1.4 to 2.9 ng mg-1 protein in Barbari. Thus, dephytinisation substantially improves iron and zinc bioaccessibility.