Carotenoid retention of biofortified provitamin A maize (Zea mays L.) after Zambian traditional methods of milling, cooking and storage.

Provitamin A biofortified maize hybrids were developed to target vitamin A deficient populations in Africa. The purpose of this study was to evaluate the degradation of carotenoids after milling, cooking, and storage among biofortified varieties released in Zambia. The biofortified maize hybrids contained 7.5 to 10.3 μg/g dry weight (DW) of provitamin A as measured by β-carotene equivalents (BCE). There was virtually no degradation due to milling. The BCE retention was also high (>100%) for most genotypes when the maize was cooked into thick (nshima) and thin porridge, but showed a lower BCE retention (53-98%) when cooked into samp (dehulled kernels). Most of the degradation occurred in the first 15 days of storage of the maize as kernels and ears (BCE retention 52-56%) which then stabilized, remaining between 30% and 33% of BCE after six months of storage. In conclusion, most of the provitamin A degradation in biofortified maize hybrids occurred during storage compared with cooking and the magnitude of this effect varied among genotypes.