Preparation of lactose-iron complex and its cyto-toxicity, in-vitro digestion and bioaccessibility in Caco-2 cell model system

Iron deficiency disorder continues to be a severe public health concern. Presently, several iron supplements are available; however, they are generally associated with higher oxidation and lower bioavailability. Iron forms a very stable and soluble complex with lactose. Therefore, the aim of the present work was to develop a lactose-iron complex with better oxidative stability, bioavailability and lower cytotoxicity. Oxidative stability of complex in linoleic acid emulsion was evaluated by TBA value and induction period. Iron bioavailability from the complex was estimated in Caco-2 cell model system. The impact of complex on cell viability was assessed using tetrazolium based colorimetric assay. It was observed in the present study that the ability of iron to catalyse the oxidation of lipids reduced in the form of lactose-iron complex as compared to the free form of iron. The complex also showed significantly higher (p<0.05) iron bioavailability than free iron salt. Higher mineral uptake and higher cellular ferritin formation were observed from lactose-iron complex in Caco-2 cells. It also showed lower toxicity than ferrous sulphate on Caco-2 cells. Hence, it could be safely concluded that lactose-iron complex could be an innovative iron fortificant with better oxidative stability and bioavailability for use in functional dairy foods in order to combat iron deficiency disorders.