Phytochemical and Trace Heavy Metal Composition of Manihot Esculenta (Crantz) and Manihot Glaziovii (Muell. Arg) Complex in Nigeria

The phytochemical and trace heavy metal composition of four varieties of Manihot esculenta (NR-8082, NR-8083, NR- 8212 and NR- 30572) and M. glaziovii were determined. Saponin, alkaloid, HCN and tannin content were investigated in the leaves, stems and tubers of plants studied. NR-8083 had the highest amount of the phytochemicals in the leaf (saponin, 5.6400a; alkaloid, 1.5110a; HCN, 68.6100a; tannin, 1.2250a). Saponin and tannin were found to be the least in the leaf of NR-8082(0.9860d and 0.4760b) respectively. Alkaloid and HCN were more in the stems of NR- 8212(1.6040a and 8.9290a) respectively, while saponin(0.3840c) and alkaloid (0.5240c) were least in the stem of M. glaziovii. Saponin and HCN were high in the tuber of NR- 8082(2.1400a and 11.7500a) respectively. Apart from Zn (85.7500b), all the trace heavy metals were high in the leaf of NR-8082(Mn, 91.7500a; Cu, 169.000a; Fe, 142.2230a). The highest mean content of manganese was found in the stem of NR-30572 (176.0000a) while copper (149.0000a) and Zinc (135.7500a) were more in NR-8083 and NR-8082 respectively. All the trace heavy metals were also low in the tubers of NR-30572(Mn, 32.0000d; Cu, 130.5000c; Zn, 57.0000e; Fe, 98.1260d). The presence of tannin and alkaloids shows that they can be used not only for nutrition purposes but also for therapeutic, both as food and in drug formulation and production.