ABSTRACT
Digestion of food serves to solubilize and release iron along with a complex, diet-dependent mixture of potential iron ligands. The iron species formed during this process diffuse across the mucous layer and interact with the brush border membrane of the duodenal enterocytes. Differing degrees of solubilization of iron from foods, together with the chemical species which result, are both determinants of iron bioavailability. Methods capable of distinguishing between different iron species are required for analyzing foods and digesta from the intestinal lumen and in vitro digestion products. The technique can give useful information on changes in iron speciation in both solid, semi-solid and liquid material, and therefore provides a useful approach to metal ion speciation in foods and digesta. Various model compounds were subjected to sequential extraction in the absence and presence of diet. Sequential extraction analysis of iron compounds in food gives speciation patterns which are specific for a given food.
