Comparative assessment of levels and dietary intake of mineral nutrients and toxic metals in different varieties of teff from Hidabu Abote, Ethiopia

Abstract

Ethiopia is the largest teff (Eragrostis teff Zucc) producer in the world. This research was intended to determine the levels of mineral nutrients and non-essential metals in the teff samples. After optimization, the samples were wet-digested using reagents (5 mL HNO3 and 1 mL HClO4), at a temperature of 230 °C for 2:30 h. Inductively coupled plasma optical emission spectrometry was used for the analysis of mineral nutrients and toxic metals in the teff samples. Under the optimum procedure, the coefficients of determination (R2) ranged between 0.9980 and 0.9999. The limits of detections (LODs) and limits of quantifications (LOQs) were in the range of 0.036–14.49 mg/kg and 0.111–43.93 mg/kg, respectively. The recovery ranged from 80.72 % to 107.79 %. The overall mean concentration in the three types of teff samples determined (mg/kg) was in the range of P (3890–4853), K (3040–3784), Ca (1906–1959), Mg (1402–1698), Fe (128–305), Mn (64–127.8), Na (50–136.5), Zn (19.8–27.3), B (1.8–21.9), Cu (4.17–6.9), Ni (2.6–4.05), Hg (1.8–4.0), Pb (0.048–3.7), Cd (0.012–2.09), As (0.02–0.24), with% RSD ranging between 0.017 and 11.1 %. The results obtained revealed that teff grain is a good source of minerals and contains a significant amount of toxic elements like Cd, Hg, As, and Pb.