Absorption of zinc and iron by rats fed meals containing sorghum food products

Abstract

Zinc and iron absorption from freeze-dried, traditionally prepared sorghum food products was studied in rats. Following a period of marginal zinc or iron depletion, groups of rats ( n = 6 in each group) were fed nutrient-balanced test meals containing one of four sorghum food products (fermented aceda ; acidic tô, cooked with tamarind extract; neutral tô, cooked in water; alkaline tô, cooked with wood ash), cooked maize gruel or an egg-white control diet, each of which was extrinsically labeled with either 65 Zn or 59 Fe before being added to the diets. Absorption was determined by whole-body retention of the initial radioisotope dose over a period of 19 days. Iron was highly available from all products tested (75–83%) with no significant difference in absorption between groups. Zinc from fermented aceda (97%) was more available than that from the other sorghum products (69–78%) or maize gruel (76%) ( P < 0·05). There was no significant difference in zinc absorption between groups fed acidic tô (78%), neutral tô (76%), alkaline tô (69%) or maize gruel (76%). The phytate content of the fermented aceda was 33% lower than that of the other sorghum foods.