ASSESSMENT OF ANTIOXIDANT ACTIVITIES OF FERMENTED WHITE MAIZE AND YELLOW MAIZE POST-FORTIFIED WITH ZOBO (HIBISCUS SABDARIFFA)

This study investigated the antioxidant ability of fermented white maize and yellow maize after post-fortification with Hibiscus sabdariffa extract. The work was aimed at improving the nutritional and functional qualities of maize-based foods, which form an important part of the Nigerian diet. Fermented maize samples were fortified with graded concentrations (0–10%) of H. sabdariffa extract, and antioxidant properties were determined using standard spectrophotometric methods. The parameters assessed included total antioxidant capacity (TAC), total phenolic content (TPC), and flavonoid content. The results showed a significant increase (p < 0.05) in all antioxidant parameters with increasing levels of H. sabdariffa fortification. Comparisons between the two maize varieties revealed that yellow maize consistently exhibited higher values of TAC, TPC, and flavonoids than white maize at all fortification levels. At 10% fortification, fermented yellow maize recorded the highest antioxidant values, indicating a synergistic effect between the natural carotenoid pigments in yellow maize and the polyphenolic compounds, anthocyanins, and flavonoids present in H. sabdariffa. The study highlights the potential of post-fortification with H. sabdariffa as an effective means of improving the functional and health-promoting properties of fermented maize. This is particularly important in the prevention of oxidative stress-related conditions such as diabetes, cardiovascular diseases, and certain cancers. In addition, the findings provide evidence that fortification of traditional staple foods can serve as a culturally acceptable and cost-effective strategy to enhance public health nutrition. In conclusion, H. sabdariffa fortification significantly improves the antioxidant profile of fermented maize, with yellow maize demonstrating superior potential compared to white maize.