Effects of aqueous soaking on the phytate and mineral contents and phytate:mineral ratios of wholegrain normal sorghum and maize and low phytate sorghum

Soaking of cereal grains has been suggested as a method to reduce their phytate content and hence increase their mineral availability. Whole and milled wholegrain, normal and low phytate sorghum and normal maize were studied. Soaking of unmilled sorghum and maize did not result in substantial reductions in phytate or mineral contents. With milled grains, phytate solubilisation was somewhat greater in maize than in sorghum after a short (1?h) soaking period but not after 6–12?h of soaking when practically all phytate had been solubilised. Also, with milled, low phyate sorghums, phytate solubilisation was not substantially higher than in their null controls. Soaking milled grain substantially reduced mineral contents and Ca?×?phytate:zinc molar ratios. However, the loss in soluble minerals could have a greater negative effect on mineral availability, compared to the positive effect of the phytate reduction. Thus, soaking does not seem to be a viable household method to improve sorghum and maize mineral availability.     

Vegetable relishes,high in β-carotene,increase the iron,zinc and β-carotene nutritive values from cereal porridges

Iron, zinc and vitamin A deficiencies are serious public health problems in sub-Saharan Africa, which can be alleviated by dietary diversification. The effects of adding cowpea leaf (CL) and orange-fleshed sweet potato (OFSP) relishes to sorghum and maize porridges on iron, zinc and β-carotene contents and bioaccessibilities were determined. Despite the high iron content of the CL relish (14.59?mg/100?g), the vegetable relishes had little effect on the iron bioaccessibility from the cereal porridges. Importantly, the addition of the CL relish increased the percentage and amount of bioaccessible zinc 2- and 3-fold, respectively. Addition of CL and OFSP relishes resulted in β-carotene contents of 10–13?mg/100?g. The β-carotene from the OFSP relish meals was double as bioaccessible than that from the CL relish meals. Addition of the vegetable relishes has real potential to improve especially the vitamin A and zinc nutritive value of cereal diets.