Abstract:
Sesame is considered to be healthful cereal for food. Sesame grains are high in energy and contain many health benefiting nutrients; minerals, antioxidants and vitamins that are essential for wellness and have positive effects on human health. The grains are incredibly rich source of many essential minerals which include Ca, Mg, Fe, Se, Zn, Mn, Cu, Co and Ni. In this study the levels of selected essential elements (Co, Zn, Mn, Cu, Fe, Ni) in white sesame grains (Setit – 1, variety) sampled from five different kebeles of Ebinat district, South Gondar Zone, Amhara Regional state of Ethiopia were measured. Known 0.5g of oven dried sesame grainpowdered samples were digested by wet digestion using 10ml mixture of HNO3 and HClO4 with the ratio of 2:1 at temperature of 110 degree centigrade. The content of the minerals in the digests were analyzed using ICP-OES and the following concentration ranges (mg/100g) were recorded in sesame seed. The concentrations between 0.597±0.006and 0.643±0.015 for Co, 9.17±0.272and 12.17±0.395 for Zn, 3.567±0.057 and 3.733±0.015 for Mn, 0.947±0.011 and 2.346±0.040 for Cu, 13.69±0.124 and 22.63±0.318 for Fe, 0.202±0.001 and 0.42 ± 0.01 for Ni.The concentration of Fe was highest followed by Zn, Mn, Cu, Co and Niin sesame seeds. Except Zn, the concentrations of these trace elements in white sesame seed (Setit-1variety)areunder the WHO safe limit (higher permissible limit) for grains but the average concentration of Zn (10.14) in this study was above the safe limit(9.94).Differences in geographical locations, soil properties, climate conditions, agrochemical usage have caused the variation among grain samples. The white sesamegrains(Setit –1 variety) grown from Ebinat arerich in Fe and Zncompared to other similar grains and in most case containsrelativelycomparable concentration of Co, MnCu and Ni with literature values. Therefore farmers in the study area would not use farming practices that increase the concentration of Fe and Zn in grains because increasing the level of these elements beyond this amount may lead to toxicant effect.
Keywords: Essential minerals,ICP-OES, Sesame(Sesame indicum L.)trace element