School of Life Sciences and Bioengineering (LiSBE), Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania; Mwalimu Julius K. Nyerere University of Agriculture and Technology, P.O. Box 976, Mara, Tanzania.
Tanzania Agricultural Research Institute (TARI) - Ilonga Centre, P.O. Box 33, Kilosa, Morogoro, Tanzania.
Food Res Int. 2022 Jun;156:111303. doi: 10.1016/j.foodres.2022.111303. Epub 2022 May 7.
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.
玉米是富含类胡萝卜素的作物之一，这些类胡萝卜素很容易转化为维生素 A，对消费者的健康有巨大影响。主要是玉米含有高热量和蛋白质，但其他微量营养素如维生素 A 的含量较少。以玉米作为主要和唯一主食的社会可能会受到维生素 A 缺乏的影响。因此，开发和生产富含微量营养素和维生素 A 的玉米品种对于改善健康非常重要。本研究对坦桑尼亚种植的玉米基因型中的 5 种类胡萝卜素成分进行了特征描述，作为提高玉米维生素 A 含量的策略。该研究涉及玉米地方品种、商业或优良品种以及自交系，以确定它们在改善营养的类胡萝卜素前体维生素 A 育种计划中的潜力。研究发现，重要类胡萝卜素成分的平均浓度，即α-胡萝卜素（AC）、β-胡萝卜素（BC）、β-隐黄质（BCX）、叶黄素（LU）、玉米黄质（ZX）、类胡萝卜素前体（ProVA）、非类胡萝卜素前体（Non-ProVA）和总类胡萝卜素（TC）在玉米基因型之间存在显著差异（P<0.001）。研究的 3 组玉米（地方品种、商业品种和育种材料（BMs）存在显著差异。对于玉米地方品种，研究的类胡萝卜素浓度（µg/g）为 AC（0.13-2.67）、BC（0.60-3.72）、BCX（0.36-1.01）、ProVA（0.89-5.29）、视黄醇（0.25-0.87）、LU（2.37-16.97）。ZX（0.16-4.41）、非类胡萝卜素前体（2.4-19.01）和 TC（3.68-25.27）；在商业或优良玉米品种中为（µg/g）：AC（0.31-3.84）、BC（0.56-6.5）、BCX（0.46-2.58）、ProVA（0.92-11.80）、视黄醇（0.15-1.82）、LU（3.28-22.39）。ZX（0.05-11.31）、非类胡萝卜素前体（2.56-28.81）和 TC（4.23-37.84）；对于玉米 BMs，AC（0.53-6.64）、BC（1.92-13.87）、BCX（0.65-6.51）、ProVA（2.69-18.62）、视黄醇（0.5-3.1）、LU（4.86-34.99）、ZX（0.06-18.58）、非类胡萝卜素前体（4.8-53.57）和 TC（9.86-76.94）。此外，研究发现，研究的类胡萝卜素浓度在有色（黄色或红色）玉米基因型中高于白色玉米基因型。本研究发现，在所研究的材料中，包括玉米地方品种、商业黄色品种和 CIMMYT 系，含有相当数量的 ProVA。在所研究的玉米基因型中确定的 ProVA 和视黄醇浓度低于每日维生素 A 需求的 15µg/g，因此根据当前的 ProVA 和视黄醇状况，很难满足维生素 A 的需求。因此，这些具有较高类胡萝卜素成分水平的玉米基因型是潜在的育种材料，可以用于玉米类胡萝卜素前体维生素 A 生物强化计划，以改善坦桑尼亚的粮食营养和生计。
