Minerals and their bioavailability in relation to dietary fiber, phytates and tannins from gluten and gluten-free flakes

Food Chem. 2020 Feb 1;305:125452. doi: 10.1016/j.foodchem.2019.125452. Epub 2019 Sep 3.


Flakes are an assortment of grain products mainly consumed for breakfast. Most of them are important source of nutrients including minerals. Twenty commercial flakes from different raw materials were included in this study, both gluten (barley, rye, spelt, wheat) and gluten-free (amaranth, buckwheat, corn, quinoa, millet, oat, rice, teff). The content of minerals (Ca, Fe, K, Mg, Mn, Na and Zn), dietary fiber (total, soluble and insoluble), tannins and phytates was determined. Moreover, the phytates:mineral molar ratios and the percentage of the realization of mineral requirements were calculated. For the first time the mineral bioavailability from the gluten and gluten-free flakes was evaluated and compared. It allowed indicating amaranth and teff products as flakes with the highest impact on the realization of daily requirements for minerals, especially for magnesium and iron. This aspect is particularly important for people on a gluten-free diet who often represent mineral deficiencies.

Keywords: Dietary fiber; Flake; Gluten-free; Mineral; Phytate; Tannin.

MeSH terms

  • Biological Availability
  • Chenopodium quinoa / chemistry
  • Chenopodium quinoa / metabolism
  • Dietary Fiber / analysis*
  • Edible Grain / chemistry
  • Fagopyrum / chemistry
  • Fagopyrum / metabolism
  • Glutens / metabolism
  • Hordeum / chemistry
  • Hordeum / metabolism
  • Millets / chemistry
  • Millets / metabolism
  • Minerals / analysis*
  • Phytic Acid / analysis*
  • Spectrophotometry, Atomic
  • Tannins / analysis*
  • Triticum / chemistry
  • Triticum / metabolism


  • Dietary Fiber
  • Minerals
  • Tannins
  • Phytic Acid
  • Glutens