Potential of moringa leaf and baobab fruit food-to-food fortification of wholegrain maize porridge to improve iron and zinc bioaccessibility

Abstract

Food-to-food fortification (FtFF) with moringa leaf (iron source) and/or baobab fruit (citric acid and ascorbic acid source) (each 13–15 g/100 g porridge dry basis (db)) was studied to improve iron and zinc nutritive quality in African-type wholegrain maize-based porridges using in vitro dialysability assay. Moringa FtFF decreased percentage and total bioaccessible iron and zinc, by up to 84% and 45%, respectively. Moringa was very high in calcium, approximately 3% db and calcium–iron–phytate complexes inhibit iron bioavailability. Baobab FtFF increased percentage and total bioaccessible iron and zinc, especially in porridges containing carrot + mango (β-carotene source) and conventionally fortified with FeSO₄, by up to 111% and 60%, respectively. The effects were similar to those when ascorbic and citric acids were added as mineral absorption enhancers. While moringa FtFF could be inhibitory to iron and zinc bioavailability in cereal-based porridges, baobab fruit FtFF could improve their bioavailability, especially in combination with conventional iron fortification.

Keywords:

• Adansonia digitata
• iron bioavailability
• mineral fortification
• Moringa oleifera
• wholegrain

Disclosure statement

The authors report no potential conflicts of interest.

Additional information

Funding

This work was funded in part by the United States Agency for International Development (USAID) Bureau for Food Security under Agreement #AID-OAA-L-14-00003 as part of Feed the Future Innovation Lab for Food Processing and Post-harvest Handling. Any opinions, findings, conclusions or recommendations expressed here are those of the authors alone. Grants for OY Adetola from the SA National Research Foundation (NRF) and The World Academy of Sciences (TWAS) (Grant UID 105494), and the University of Pretoria and from the NRF for the work (Grant 119549) are acknowledged, as is the technical assistance of E Stacey and J Toye.