Browsing by Author "Msungu, Selly"

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Characterization of Provitamin A Status and Distribution in Commercial Grown Maize Varieties in Tanzania
(East African Journal of Science, Technology and Innovation, 2022-02-16) Msungu, Selly; Venkataramana, Pavithravani; Mushongi, Arnold
Provitamin A carotenoids are important as precursors for vitamin A, essential for stronger immune system and eyesight. Consumption of a plant-based diet rich in provitamin A such as provitamin A maize is an easy and affordable source of vitamin A. The majority of the commercially grown maize varieties in Tanzania are white whose provitamin A status is uncertain and undocumented. The existing current information suggests that white maize varieties have low provitamin A, an active form of vitamin A, thus putting maize consumers at risk of vitamin A deficiency (VAD). Characterization of provitamin A status in commercial maize varieties grown and consumed in Tanzania is important to provide baseline information required for vitamin A rich-maize improvement programs. Therefore, this study was conducted to map the status of provitamin A in commercial maize varieties to accrue the information needed to improve maize nutrition quality toward controlling VAD in the country. The study involved 14 maize varieties including commercial yellow and white pigmented maize from 3 regions of Tanzania. From maize samples, carotenoid extraction was conducted based on published protocol. The concentration of beta carotene (BC), beta-cryptoxanthin (BCX), alpha-carotene (AC) were determined by an ultraviolet spectrophotometer and provitamin A computed for the individual carotenoids components. The study found that the concentration of provitamin A and associated carotenoids significantly differed (p<0.001) among varieties studied. The mean concentration (in μg/g) for provitamin A and its components in range as provitamin A (2.64-6.50), BC (1.91-4.66), BCX (0.649-1.21), and AC (0.819-1.46). The concentrations of provitamin A in the studied maize varieties were below the recommended levels (15 μg/g). The low concentrations of provitamin A among commercial maize varieties signify the need for introgressions of provitamin A in the adapted maize genotypes for ensured intake of vitamin A.
A review on the trends of maize biofortification in alleviating hidden hunger in sub-Sahara Africa
(Elsevier Ltd., 2022-06-01) Msungu, Selly; Mushongi, Arnold; Venkataramana, Pavithravani; Mbega, Ernest
Micronutrient deficiency is a major problem affecting many people in developing countries who solely depend on maize as their single source of calories. Vitamin A deficiency is one of the health problems associated with micronutrient deficiency. It is caused by insufficient intake of food rich in vitamin A among vulnerable groups leading to impaired growth, reduced life span, and economic losses among resource-poor families. Strategies such as vitamin A supplementation, food fortification, and diet diversification have been adapted to combat vitamin A deficiency (VAD). However, these approaches have benefited urban dwellers leaving rural residents with deficiency sufferings, as they lack access to these alternatives. Biofortification of maize by breeding with higher provitamin A content holds immense promise as a cost-effective and sustainable approach in alleviating VAD in sub-Saharan African maize consumers. Biofortified maize has a greater potential to alleviate vitamin A deficiency in these countries. Despite the existence of biofortification programs in Africa, there is little documentation on what has been conducted, challenges, and future of maize biofortification programs in Africa; this limits any strategic planning required to produce maize varieties rich in micronutrients, including vitamin A. Therefore, the present study is a detailed systematic review to highlight the past, present, and future success of provitamin A maize biofortification and its adoption challenges in sub-Sahara Africa as a strategy for combating vitamin A deficiency.
Status of carotenoids in elite and landrace maize genotypes: Implications for provitamin A biofortification in Tanzania
(Elsevier Ltd., 2022-06-01) Msungu, Selly; Mushongi, Arnold; Venkataramana, Pavithravani; Mbega, Ernest
Maize is among the crops containing carotenoids that are easily converted to vitamin A and have an enormous influence on consumers' health. Principally maize has high calories and proteins but has less number of other micronutrients such as vitamin A. Societies that use maize as their main and sole staple food are likely to be affected by vitamin A deficiency. Thus, development and production of maize varieties rich in micronutrients and vitamin A are important for improved health. This study characterized 5 carotenoid components in maize genotypes grown in Tanzania as a strategy for improving vitamin A content in maize. The study involved maize landraces, commercial or elite varieties, and inbred lines in determining their potential for provitamin A breeding programs for nutrition improvement. The study found that mean concentration of important carotenoid components, i.e., alpha carotene (AC), beta-carotene (BC), beta-cryptoxanthin (BCX), lutein (LU), zeaxanthin (ZX), provitamin A (ProVA), non-provitamin A (Non-ProVA), and total carotenoids (TC) varied significantly (P < 0.001) among maize genotypes. The 3 maize groups studied (landraces, commercial varieties, and breeding materials (BMs) varied significantly. For maize landraces, the concentration (µg/g) of studied carotenoids were AC (0.13–2.67), BC (0.60–3.72), BCX (0.36–1.01), ProVA (0.89–5.29), Retinol (0.25–0.87), LU (2.37–16.97). ZX (0.16–4.41), Non-ProVA (2.4–19.01), and TC (3.68–25.27); in commercial or elite maize varieties were (in µg/g): AC (0.31–3.84), BC (0.56–6.5), BCX (0.46–2.58), ProVA (0.92–11.80), Retinol (0.15–1.82), LU (3.28–22.39). ZX (0.05–11.31), Non-ProVA (2.56–28.81), and TC (4.23–37.84); and for maize BMs AC (0.53–6.64), BC (1.92–13.87), BCX (0.65–6.51), ProVA (2.69–18.62), Retinol (0.5–3.1), LU (4.86–34.99), ZX (0.06–18.58), Non-ProVA (4.8–53.57), and TC (9.86–76.94). Furthermore, the study found that the concentration of studied carotenoids was higher in pigmented (yellow or red) maize genotypes than in white maize genotypes. The current study found an appreciable amount of ProVA in studied materials, including maize landraces, commercial yellow varieties, and CIMMYT lines. The concentration of ProVA and retinol determined in studied maize genotypes were below 15 µg/g a daily vitamin A requirement, thus based on the current ProVA and retinol status it is difficult to meet Vitamin A requirement. Therefore, these maize genotypes with promising levels of carotenoid components are potential breeding materials that can be used in maize provitamin A biofortification program for improved food nutrition and livelihoods in Tanzania.