Iron Fortification in Parboiled Rice—A Rapid and Effective Tool for Delivering Iron Nutrition to Rice Consumers

Abstract

Parboiled rice production accounts for nearly half of the world’s rice production. Its markets and consumer base are firmly established in South Asia and Africa where Fe-deficient populations are mostly concentrated. Our research group has pioneered the technology of Fe-fortification in parboiled rice and demonstrated its feasibility in significantly increasing Fe concentration in the endosperm (white rice) and its bioavailability in rice based diet. Fortification with Fe-EDTA during parboiling resulted in 10 to 50 folds increase in grain Fe concentration, depending on the grain properties among different rice varieties. However, the broken rice of Fe-fortified parboiled rice contained 5 times the Fe concentration of the full grain, which is often bought and consumed by people in low income category. The bioavailability of the fortified Fe is closely correlated with increasing Fe concentration in white rice (r = 0.90, p < 0.01). The retention rates of the fortified Fe in the white rice range from > 50% to almost 100%, despite repeated rinsing before cooking depending on rice varieties. Perls’ Prussian blue staining and prolonged polishing showed that the in vitro Fe penetrated into the interior of the endosperm. Fortification at the rate up to 250 mg Fe kg–1 paddy rice has no deleterious effects on appearance, color and sensory quality and overall acceptance by parboiled rice consumers. It increased Fe concentration up to 27 mg Fe kg–1 of in white rice, compared with 5 mg Fe kg–1 in unfortified parboiled and raw white rice. As a result, we can conclude that parboiled rice is a ready and effective tool for improving Fe nutrition of rice consumers in these regions.