Dioscorea Abyssinica , commonly known as yam, is an indigenous plant
in Ethiopia. Its root tuber is used as staple and co-staple food in
South Nation Nationality People and Regional State of Ethiopia. This
study was carried out to analyze the selected mineral nutrients in the
tuber and flour of D. abyssinica grown in different parts of the
country for human consumption. Samples collected from five different
areas were analyzed for eleven metals (Ca, Mg, Fe, Zn, Cu, Mn, Co, Cr,
Ni, Cd and Pb) by flame atomic absorption spectrometry and two metals
(K and Na) by flame emission spectrometry. Known weight of oven-dried
sample was wet-digested using 3 mL of (69–72%) HNO3 and 1 mL of
(70%) HClO4, for 2 h at variable temperature (120–270° C).
The validity of the optimized procedure was evaluated by the analysis
of spiked samples whose recovery was in the range of 92–105%. The
mean concentration range (in μg/g) of each metal in D. abyssinica
samples were K (8,469–13,914), Na (133–405), Ca
(172–448), Mg (180–354), Fe (28.3–144.5), Mn
(12.0–14.5), Zn (12.3–44.5), Cu (7.26–17.6), Co
(1.91–8.68), Cr (0.86–3.41) and Ni (2.43–5.31). D.
abyssinica could be good sources of essential trace metals to the
individuals, more particularly Fe and Zn were higher than the entire
trace metals in the samples investigated while Cd and Pb were in minor
quantities and hence the plant is free from toxic heavy metals.
Consuming 100 g of this tuber per day contribute the following
concentration range of Fe, Zn, Cu, Mn, Co, Ni and Cr in mg/100 g per
day: 2.8–14.4, 1.2–4.5, 0.73–1.8, ND–1.5,
ND–0.87, 0.24–0.53 and 0.09–0.34 mg/100 g,
respectively. Statistical analysis revealed that significant variations
in metal concentrations among the sampling sites were observed for some
of the metals when pair wise test was made while insignificant
variation were seen for the remaining metals. D. abyssinica could be a
better source of K, Ca, Fe and Zn to human compared to the common
cereal flours (barley, wheat and red teff flour) as well as tuber food
products like potato, cassava, yam, and enset ( Ensete ventricosum ),
while it could be an alternative source of the other essential mineral
nutrients to the individual daily mineral intake
