Determination of Levels of Essential and Non-essential Metals and Nutritional Value in Mung Bean Seed (Vigna radiate L.) Cultivated in Wolaita Zone, Southern Ethiopia

Abstract

Background: Mung bean (Vigna radiate L.) is an important legume crop grown worldwide from tropical to sub-tropical areas. The experiments were conducted on the mung bean to determine the level of essential and non-essential metals and proximate composition. Methods: In this study, the levels of selected essential metals and non-essential metal were determined from mung bean (Vigna radiate L.) in Kindo Koysha District, Wolaita Zone, Ethiopia. Wet digestion method with a mixture of 6 ml of concentrated HNO3:HClO4 (5:1 v/v) was used for digestion of the mung bean samples and a concentrated reagent mixture of 6 mL aqua-regia (3:1 ratio of HCl to HNO3) and 1.5 mL H2O2 was used for digestion of the soil samples. Result: The results obtained revealed that the concentrations of metals in the mung bean samples in mg/kg dry weight were in the range of Ca (1418.02-1698), Mg (2422-2492.4), Na (88.9-106.7), K (3670-3716.8), Fe (196.2-235.5), Zn (72-103), Mn (51-97.6), Cu (7.8-27.4). The non-essential metal Cr was not detected in mung beans. The proximate composition of mung bean in the range of crude protein (17.86-28.29%), crude fat (1.05-1.49%), ash content (2.9-3.35%) and moisture (5.76-7.57%). Mung bean was found to be an excellent source of essential minerals and protein content and low in fat content.