Mineral contents of Ethiopian red and green apple fruits: A comparison with WHO/FAO standards

Demisew Jemaneh and Bhagwan Singh Chandravanshi

Abstract

The aim of this study was to evaluate the macro- and micro essential and nonessential minerals in apple fruits collected from farmland in Wollega, Chencha, Ankober (Ethiopia) and Addis Ababa which are imported to Ethiopia from South Africa and Israel. Samples were wet-digested using 3 mL HNO3 and 1 mL HClO4 for 2:15 hours at 210 oC. Selected metals (Mg, Ca, Fe, Mn, Cu, Al, Zn, Cr, Co, Ni, Cd and Pb) were determined by microwave plasma-atomic emission spectroscopy. The validity of optimized procedure was evaluated by the analysis of spiked samples and recoveries were in 90.8-106% range. The mean concentration range (mg/kg) of metal in fruit samples were Ca (1065-36275, 1013-36143), Mg (27- 153, 78.3-139), Fe (103-276, 123-241), Mn (13.5-13.7, 11.5-16.3), Cu (5.13-6.56, 4.11-12.6), Al (77.8-129, 52.5-89.6), Zn (41.3-73.6, 47.4-54.4), Cr (6.15-10.04, 6.57-7.14), Co (6.57-7.14, 1.70-2.35), Ni (1.33-2.37, 1.43-7.66), respectively. Cd and Pb were not detected. Analysis of variance showed significant difference (p = 0.05) in the levels of Cu, Al and Co among sampling sites in green apple fruit while all the other metals did not show significance difference. Red apple fruit showed a significance difference in the levels of Fe, Mn, Cu, Zn, Cr and Co metal while the other metals showed insignificance differences. Pearson correlation coefficients indicated strong, moderate and weak correlation between different pairs of metals in both the green and red apples.