Vitamins Are Retained in Fortified Whole‐Grain Maize Meal When Stored Under Tropical Conditions When Optimal Storage Practices Are Used

Background and Objective To ensure provision of essential micronutrients to at‐risk maize‐consuming populations, their stability in stored fortified whole‐grain maize meal (FWGMM) is essential. Vitamin stability in commercial FWGMM was studied over 6 months under two real‐world tropical conditions (overall average 25.3°C, 53.5% relative humidity (RH) and 19.4°C, 66.5% RH) in grain stores. The maize was pre‐dried before milling and optimal storage practices were employed. Findings No loss in Vitamin A (retinol palmitate), B1 and B2 (total and endogenous) occurred, contrary to other fortified maize meal storage studies without pre‐drying and/or using suboptimal storage practices. Alternative treatments to maize pre‐drying were investigated in an accelerated storage study at 40°C, 65% RH using similar storage practices. There was no loss in Vitamins B1 and B2 (total and endogenous) with any treatment including the not pre‐dried maize control. Conclusions The vitamin stability in FWGMM during storage is attributable primarily to the use of a polyethylene inner liner in the sacks which largely prevented moisture ingress and to storage in semidarkness which prevented vitamin photodegradation. Maize pre‐drying provides additional assurance against moisture‐induced degradation. Significance and Novelty These simple practices can help provide the full benefit of micronutrient‐fortified WGMM to consumers.