Bioactive compounds of freshly harvested open pollinated varieties (OPV) of orange maize (zea mays): varietal, maturity, and boiling methods effects

Biofortified open pollinated maize varieties (OPV) could be used to address the problem of micronutrient deficiencies in developing countries. This study aimed at investigating the effects of maturity 20, 27, and 34 days after pollination (DAP) and processing (boiling with and without husks) on the bioactive components (carotenoids, phytic acid, tannins, and vitamin C) on fresh orange OPV maize. The fresh and processed samples were analysed for bioactive components using standard methods of analysis. Carotenoids, phytate, and vitamin C showed a general significant (P ≥ 0.5) increase in concentrations across the studied harvest maturity stages. The optimum retention for most bioactive compounds was found at 27 DAP for cobs of orange OPV maize boiled with and without husks. Boiled maize with husks showed higher retention of most bioactive compounds than boiled maize without husks where the mean concentrations of the bioactive compounds increased across the harvesting stages except for tannin and vitamin C that showed a decrease at 34 DAP. Varieties 1 and 5 showed a higher provitamin A value than the grand mean of 6.04 μg/g at 27 DAP but variety 5 had the highest concentration of 10.2 μg/g. Variety 1 showed a higher concentration of provitamin A value than the respective grand mean at the three harvest maturity stages for OPV maize boiled with husk intact. The retention of more bioactive compounds during boiling with or without husks is found to be genotype dependent. The information from this study could guide the food scientists, nutritionists, and consumers on the best boiling methods to process OPV orange maize for optimum retention of bioactive components.