Iron and zinc availability and some physical characteristics from extruded products with added concentrate and hydrolysates from bovine hemoglobin

Four hydrolysates were obtained from bovine hemoglobin concentrate (BHC) and used to fortify extruded maize products. Extrusion was carried out with a Brabender single-screw extruder. Physicochemical properties from extruded products were measured. The iron availability was estimated by the dializability method, which measures the mineral dialyzed after a double digestion simulating physiological processes. The physicochemical properties of the extruded products were not affected by fortification, with the exception of total soluble solids. The enzymic hydrolysis increased the iron dializability with respect to the substrate. The highest value of iron dializability corresponded to the more hydrolysated sample. Extruded products fortified with BHC hydrolysates showed higher iron dializability than those fortified with BHC. However, iron dializability corresponding to BHC is lower than that expected from heme iron. Therefore, heme-iron availability is low when it is determined in the absence of meat proteins, and hydrolysis could increase potential iron availability.