Constitutive Changes in Nutrients and Phytochemicals in Kernels of Aluminium-Tolerant Maize (Zea mays L.)

Abstract

Maize (Zea mays L.) is among the three most important food crops worldwide. Maize growth is affected by high aluminium content in acid soils, which constitute nearly 50% of the world’s cultivable area. Therefore, the cultivation of aluminium-tolerant maize hybrids could be a healthier alternative and an attractive food source in these regions. In this regard, to produce hybrids kernels, 16 inbred lines aluminium-tolerant (Al-T) and aluminium-susceptible (Al-S) maize were screened for their constitutive patterns of selected nutrients and phytochemicals. Proximate analysis, free phenolic acids (FPA) and cell wall-bound phenolic acids (CPA) contents, as well as antioxidant capacity (AOX) were assayed in the anatomical kernel parts (pericarp, endosperm, and germ). Kernels of Al-T maize contained significantly higher germ protein, oil, and fibre (2.9, 3.0, and 0.5%, respectively) than Al-S kernels (1.9, 1.8, and 0.3%, respectively). Importantly, the nutraceutical contents in terms of pericarp FPA and germ CPA were significantly higher in kernels belonging to Al-T maize (92 mg and 140 mg EGA/100 g). The highest AOX was observed in germ CPA of Al-T kernels (9.0 mmol TE/100 g). The results herein indicate that Al-tolerance mechanisms induce positive changes in the nutrients and phytochemicals; this implies that the hybrids generated using Al-T maize inbred lines could emerge as an attractive source of nutrients and phytochemicals in farming regions containing acid soils.