Minerals, phytic acid and tannin contents of 18 fruits from the Brazilian savanna

The present study evaluated the nutritious potential of 18 fruits, all native of the Brazilian Cerrado biome. Mineral contents were determined by inductively coupled plasma atomic emission; phytic acid and tannin contents by a colorimetric and titrimetric method, respectively; and the potential mineral bioavailability by the molar ratio of phytic acid/mineral. Baru nut showed the highest zinc, copper, iron, phosphorus and magnesium content, and, together with macaúba, showed also the highest calcium content and caloric value. Macaúba, pitomba, ingá and murici fruits were classified as a source of iron. The jatoba and baru nut had the highest concentration of phytic acid and tannins. The [phytic acid]/[iron] and [phytic acid]/[zinc] molar ratios were higher than the critical values (14 and 10, respectively) only in the baru nuts, which suggests that iron and zinc bioavailability is low in this nut. The [phytic acid]/[calcium] molar ratios were lower than the critical value (1.56) in all analyzed fruits, which suggests that calcium is bioavailable in the fruits.