Physicochemical characterization of mineral (iron/zinc) bound caseinate and their mineral uptake in Caco-2 cells

Milk proteins (especially caseins) are widely accepted as good vehicle for the delivery of various bioactive compounds including minerals. Succinylation is one of the most acceptable chemical modification techniques to enhance the mineral binding ability of caseins. Addition of minerals to succinylated proteins may alter their physicochemical and biochemical properties. Physicochemical characteristics of succinylated sodium caseinate (S. NaCN)-mineral (iron/zinc) complexes were elucidated. Chromatographic behaviour and fluorescence intensity confirmed the structural modification of S. NaCN upon binding with minerals. The bound mineral from protein complexes showed significantly higher (P < 0.05) in vitro bioavailability (mineral uptake) than mineral salts in Caco-2 cells. Also, iron bound S. NaCN showed higher cellular ferritin formation than iron in its free form. These mineral bound protein complexes with improved bioavailability could safely replace inorganic fortificants in various functional food formulations.