Improved processing method enhances essential trace elements in zea mays and sorghum bicolor flours to reduce hidden hunger

Background: Zea mays (ZM) and Sorghum bicolor (SB) contain essential minerals, but leaching during traditional wet-sieving process may exacerbate their loss and contribute to hidden hunger. Objective: To evaluate and compare essential trace element levels in modified processed and traditionally processed Zea mays and Sorghum bicolor flours. Methods: 20 grams of ZM and SB (n = 3) were cleaned and soaked separately in water for 72 h, split into two and processed by (1) Modified processing method, which involved sun-drying and dry-milling the soaked grains directly to ZMmp and SBmp flours. (2) Traditional processing method, which involved wet-milling the soaked grains, sieving with water, pressing the sediments, and sun-drying to ZMtp and SBtp flours. Essential trace elements (ETEs) contents in the flours were determined using Atomic Absorption Spectrophotometry. ETEs in both methods were compared using paired samples t-tests. Results: There were significant higher ETEs (mg/kg), expressed as mean difference (ZMmp-ZMtp) in Fe (18.11±0.24, p < 0.001), Cu (17.75±0.05, p < 0.001), Cr (14.23±0.06, p < 0.001), Mn (12.87±0.08, p < 0.001), Co (12.77±0.02, p < 0.001), Zn (11.23±0.41, p < 0.001), and Se (2.41±0.06, p = 0.001) at 95% CI; significant mean difference (SBmp-SBtp) in Zn (5.24±0.49, p = 0.048), Cu (0.7 ± 0.011, p < 0.001), Se (5.54±0.010, p < 0.001) and Mo (1.44±0.01, p < 0.001) at 95% CI. Conclusion: Modified processing method significantly improved ETEs concentrations in Zea mays and Sorghum bicolor flours. It may provide affordable, locally adopted, practical approach to improve dietary ETEs intake in Nigeria and regions facing the challenge of hidden hunger.