Abstract

Effect of enrichment and aqueous extraction on Ca, Fe, Zn, hexa (IP-6), and penta (IP-5) inositol phosphate content of slurries or porridges prepared from fresh and stored maize flour (MF) was investigated. IP-5 + IP-6 in fresh MF was higher than stored but after soaking in water and decanting, more IP-5 + IP-6 was lost from fresh MF, so final [Phy][Zn] molar ratios became similar (18 compared with 20). Enriching MF porridges with fish flour increased Ca and Zn, and after soaking in water and decanting reduced IP-5 + IP-6, thus decreasing [Phy]:[Zn], [Phy]:[Fe], and [Phy]:[Ca] molar ratios. Using Ca, Fe, Zn, IP-5 + IP-6 values for soaked enriched porridges, simulated Ca, Fe, and Zn intakes for Malawian infants were higher, but still inadequate.

This study aimed to develop and assess the feasibility of a home-based method to reduce the phytate content of maize and improve zinc bioavailability from maize-based complementary diets in rural Malawi. A method of extracting phytate through the soaking of pounded maize was developed, and found to reduce phytate content to 49% of unrefined maize. An educational program was used to teach the processing method to mothers of children receiving complementary foods in rural Malawian communities. Samples of maize flour prepared by this process by participants were collected and analysed for phytate and zinc content. Of these, 70% of samples were found to be adequately prepared; mean phytate content of these samples was 48% of unprocessed, unrefined maize flour controls. Most participants found the cooked product to have an acceptable taste (99%) and texture (68%), and felt the processing method took little or no extra time (86%) and was culturally acceptable (96%). The phytate and zinc content of the processed maize flour samples analysed from community prepared samples was substituted into the dietary analysis of complementary foods for 9- to 11-month-old children (n = 31). The bioavailability of zinc from the complementary diet would predict an increase from low (24%) to moderate (33%) levels.