Analysis Of Essential Trace Elements In Soils, Amaranthus Cruentus And Amaranthus Hypochondriacus Grains, Leaves And Stems From Selected Parts Of Kenya

ABSTRACT

Kenya has been experiencing rising cases of diseases such as diabetes, tuberculosis, liver complications, HIV/AIDS among others. Management of these conditions can be enhanced by use of plant-based trace elements. There is a need therefore to investigate crops that can provide a cheap source of these essential immune boosting trace elements. Grain amaranth is grown in different parts of Kenya including Bureti, Mt Elgon, Bondo, Meru and Embu. However, little research has been reported on the levels of trace elements in the amaranth plants in Kenya. Therefore this study analysed the levels of zinc, copper, manganese, chromium and selenium in Amaranthus cruentus (L-) and Amaranthus hypochondriacus (L-) leaves, stems and grains obtained from Kenyatta University, Bureti, Mt Elgon, Bondo, Meru and Embu. The study also analyzed the levels of the same elements in the soils in the areas in which the plants were grown. The analysis was done by Atomic Absorption Spectroscopy (AAS). The data was analyzed by use of statistical program for social scientists (SPSS) computer software version 11.5. Analysis of variance was used to compare the levels of trace elements at different maturity stages and from different areas. The mean levels of the trace elements in mg/100 g in the soils from Kenyatta University were: Zn (5.908), Cu (1.056), Mn (37.303), Cr (0.665), and Se (0.285). The soils from Bureti had the mean amounts of Zn, Cu, Mn, Cr and Se of 21.160, 2.093, 95.741, 1.240 and 0.150 mg/100 g. The mean levels (mg/100 g) contained in the soils from Mt Elgon were: Zn (6.960), Cu (1.134), Mn (52.567), Cr (1.059) and Se (0.305). The trace elements mean content (mg/100 g) of A. cruentus leaves were Zn (5.040), Cu (1.261), Mn (26.603), Cr (0.467) and Se (0.033). The mean amount of Zn, Cu, Mn, Cr and Se present in A. hypochondriacus leaves were 5.495, 1.264, 24.340, 0.309 and 0.054 mg/100 g respectively. The levels of Zn and Cr in the leaves of both species increased with the plants’ maturity from 25 to 50 days and then declined from 50 to 75 days while those of Cu, Mn and Se decreased with the plants’ ages. Significant differences (P