OBJECTIVE: Ferrous sulphate (FeSO4) is a widely used iron (Fe) supplement/fortificant, however, it causes gastrointestinal (GI) side-effects and has a poor sensory profile. Encapsu-lation approaches using biocompatible matrices may limit detrimental effects whilst potential-ly enhancing absorption. Studies in humans have shown meat protein fractions to significant-ly enhance non-haem iron absorption. Hydrolysed beef protein (Beef Protein Isolate; BPI) has high protein content (> 95%) and is available as a nutritional supplement. The aim of this study was thus to develop a protocol to formulate ferrous iron using BPI as matrix material and assess suitability for oral delivery applications.
MATERIALS AND METHODS: Nanoparticles encapsulating FeSO4 in a protein (BPI; Hy-droBEEF™) polysaccharide (chitosan-HCL) matrix were prepared using complexation meth-od. Fe incorporation efficiency was determined by colorimetric detection. Nanoparticle physi-ochemical characteristics were assessed by particle size and microscopy analysis. Cellular iron uptake and cytotoxicity was evaluated using the human intestinal cell line Caco-2 in sim-ulated GI fluid.
RESULTS: BPI nanoparticles (200 - 500 nm) entrapping Fe (and Fe-free equivalents) were successfully fabricated using an optimised protocol. Optimum ratio of protein : polysaccha-ride : Fe was established. BPI-Fe nanoparticles demonstrated intestinal iron absorption (in-tracellular ferritin as marker) significantly higher than FeSO4 control (n = 6, P ≤ 0.05), and were non-toxic under experimental conditions (48 h incubation).
CONCLUSION: In this preliminary study, we demonstrate the first example of using BPI as an innovative matrix material for iron formulation. The high intestinal absorption and non-toxic profile of this formulation have major implications for food fortification and supplementation applications.