DETERMINATION OF THE AMOUNT OF ZINC IN PURE LINE MAIZE AND SEASONAL VARIATIONS IN GRAINS AND SILKS GROWN ACROSS NIGERIA.

Abstract

Approximately, 17 percent of the world's population is at risk of zinc (Zn) deficiency. According to literature maize grains and silks are rich in Zn, and the amount varies reflecting different varieties and ecosystems. The amount of Zn in some pure line maize and seasonal variations in grains and silks grown across Nigeria's six geopolitical and seven vegetation zones were determined using acid digestion, and analysis by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The amount of Zn in the pure line (22.40 mg kg- 1 to 22.46 mg kg-1) and the open-pollinated (22.39 mg kg-1 to 22.48 mg kg-1) maize grains are within the same range, likewise, the white and yellow maize silks (27.99 mg kg-1 to 28.10 mg kg-1) but are higher than the amount in their respective grains. The Mann-Whitney U test at 0.05 significant level was used to evaluate the seasonal variation of Zn. There is no significant difference between the amount of Zn in the white maize grains, likewise, the white and yellow maize silks grown in the dry and rainy seasons across Nigeria's geopolitical and vegetation zones. Except in the South-East where the amount of Zn in the yellow maize grains is significantly higher in the dry season compared with the rainy season. Potentially, 0.67 kg, 0.54 kg, 0.45 kg, and 0.22 kg of the maize grains, and 0.54 kg, 0.43 kg, 0.36 kg, and 0.18 kg silks are recommended for Zn daily dietary intake for men, females, adolescents, and formula-fed babies, respectively.