Iron Bioavailability of Sorghum, Cowpea, Corn and Soybean Fortified Blended Foods

Abstract

Fortified blended foods (FBFs) are widely used for food aid. Corn and soybeans are the common components of FBFs. Resistance to genetically modified (GMO) foods led to interest in non-GMO commodities like sorghum and cowpea. Both sorghum and cowpea are rich in iron; however their iron bioavailability is poor due to the presence of tannins and phytates. A food processing technique, extrusion cooking reduces these anti-nutrients in foods. Hence, we developed extruded sorghum, soybean and cowpea FBFs. The objective of our study was to determine whether the iron bioavailability from extruded sorghum-cowpea and sorghum-soy FBFs is equal/ better than non-extruded corn-soy FBFs. Eighteen different FBFs; sorghum-cowpea (n=8), sorghum-soy (n=5) and corn-soy (n=5) were prepared and iron bioavailability was assessed using the in-vitro digestion/Caco-2 cell model. Iron bioavailability was determined by measuring Caco-2 cell ferritin (ng ferritin/mg cell protein) formation in response to 12 hour treatment with aqueous fraction collected from digested FBFs. Control cells were collected at time zero, to measure basal ferritin content. There was no significant difference in ferritin levels between newly developed extruded sorghum-cowpea, sorghum-soy, corn-soy and traditional corn-soy FBFs. Ferritin was higher in all the blends compared to control. Iron bioavailability of extruded sorghum-cowpea, sorghum-soy FBFs is comparable to traditional corn-soy FBFs. Supported by USDA-MFFAPP.