Elemental composition of teff (a gluten-free grain), maize and wheat: Staple crops in the Main Ethiopian Rift Valley.

Teff, maize, and wheat are the major cereals grown in volcanic ash-rich soils of the Main Ethiopian Rift (MER) Valley. Teff is a gluten-free cereal native to Ethiopia, used for making a local flat bread called injera, and is getting popularity globally due to its nutritional value (gluten-free and high fiber content). Teff can thus be an alternative diet for the treatment of celiac disease, a lifelong intolerance to gluten. This study aims to assess the distribution of toxic and essential elements in these staple cereals using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and compare with mineral composition of wheat, and maize consumed in the Main Ethiopian Rift Valley. We found significantly higher mean concentrations (in mg/kg) of Mg (1400), Ca (1210), Na (33), Fe (159), Mn (71), Sr (5.6), and Cu (4.8) in teff compared to wheat and maize. Maize had the lowest concentrations of these essential elements. Mean concentrations (in μg/kg) of As (24.7) and Pb (70) in teff were relatively higher compared to wheat and maize, which had similar values of As (4.5) and Pb (8.9). Teff and wheat had similar Cd concentrations (in μg/kg) of 4.8 and 5.4 respectively compared to maize (1.5). Cadmium concentrations were below the Codex standard established for Cd in cereal grains (100 μg/kg). Only one teff sample exceeded the Codex standard set for Pb (200 μg/kg) in cereal grains. This study provides information on nutritional values and food safety of maize, wheat, and teff; the latter is becoming an alternative gluten-free diet for celiac patients in countries where wheat is commonly a staple food.