Effect of phytase treatment of sorghum flour, an alternative for gluten free foods and bioaccessibility of essential minerals

This study evaluated the effect of phytase treatment on the bioavailability of iron (Fe), calcium (Ca), zinc (Zn), and myo- inositol phosphate fractions in sorghum flour; and characterized its macronutrients and minerals. The proximate composition and mineral content indicated that, sorghum flour has a nutritional potential superior to wheat and maize. The results obtained in the solubility and dialysis assays indicated that, naturally occurring minerals (without phytase treatment) in sorghum flour, presented considerable bioaccessibility; reaching 32, 47 and 67% of dialyzable Fe, Zn, and Ca respectively. The use of phytase had a positive influence on the reduction of myo- inositol phosphates, mainly the IP6 fraction, present in sorghum flour samples, and an increase in the soluble percentage (Fe 52% for one sample, for Zn higher than 266%) and dialyzed minerals (Fe 7.8–150%; Zn 19.7 for one sample; and Ca 5–205%) for most samples. Therefore, the essential minerals naturally occurring in sorghum have an absorption potential; and the use of phytase reduced the IP6 fraction and improved the availability of the minerals evaluated.