Abebe, Adane (2015) Studies on the Levels of Essential and Non-Essential Metals in the Raw and Processed Food (Kolo and Bread) of Maize/Corn (Zea mays L.) Cultivated in Selected Areas of Ethiopia. Masters thesis, Addis Ababa University.
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Abstract
Maize (Zea mays L.) is one of the most widely cultivated cereal crops in the world. It is among the staple food crops produced globally. It is also used for manufacturing of different industrial products. In this study the levels of essential and non-essential metals in raw maize seeds and its processed food (kolo and bread) were determined in samples collected from three selected areas (Shendi, Finote Selam and Debre Tabor), Ethiopia. After proper sample pretreatment, the volumes of reagents to be used, digestion temperature and digestion time were optimized. Then using the optimized conditions sample preparation was made and levels of metals were determined by flame atomic absorption spectrometry (for major metals) and graphite furnace atomic absorption spectrometry (for trace and heavy metals). The accuracy of the optimized procedure was evaluated by analyzing the digest of the spiked samples with standard solution and the percentage recoveries varied from 91.2% to 109%. The concentration determined (mg/kg dry weight) were in the ranges K (1589–2036), Na (125–195), Mg (304–411), Ca (66.5–178), Cr (0.17–1.72), Mn (0.52–3.98), Fe (16.5 –146 ), Co (0.34–0.76), Cu (0.04–2.72), Zn (59.2–116) and Pb (0.31–3.41) but the concentration of Cd and Ni were below the detection limit. K and Fe were with the highest concentration from major essential and trace metals, respectively. A statistical analysis of variance (ANOVA) at 95% confidence level indicated that there is significant difference in the levels of all metals among the three samples means except K, Mg and Pb. The results indicate that Ethiopian maize seed is a good source of essential metals and free from the toxic metal Cd but not from Pb, the concentration of Pb is higher than the WHO guideline (0.2 mg/kg).
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | Maize seed (Zea mays L.), essential metals, non-essential metals, flame atomic absorption spectrophotometry, graphite furnace atomic absorption spectrophotometry |
| Subjects: | Q Science > Q Science (General) Q Science > QD Chemistry Q Science > QH Natural history > QH301 Biology Q Science > QK Botany S Agriculture > S Agriculture (General) S Agriculture > SB Plant culture |
| Divisions: | Africana |
| Depositing User: | Selom Ghislain |
| Date Deposited: | 18 Jun 2018 12:26 |
| Last Modified: | 18 Jun 2018 12:26 |
| URI: | http://thesisbank.jhia.ac.ke/id/eprint/4411 |
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