In vitro iron absorption of α-lactalbumin hydrolysate-iron and ß-lactoglobulin hydrolysate-iron complexes.

To study the feasibility of promoting iron absorption by peptides derived from α-lactalbumin and ß-lactoglobulin, the present work examined the transport of iron across Caco-2 monolayer cell as in vitro model. Caco-2 cells were seeded in bicameral chambers with α-lactalbumin hydrolysate-Fe (α-LAH-Fe) complex and ß-lactoglobulin hydrolysate-Fe (ß-LGH-Fe) complex, α-LAH and iron mixture, ß-LGH and iron mixture, FeSO4 and ascorbic acid mixture, and FeSO4. In addition, the cytotoxicity of α-LAH-Fe and ß-LGH-Fe complexes were measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The iron absorption and ferritin content were assessed using the coupled in vitro digestion/Caco-2 cell model. Results support that peptide-iron complexes can promote ferritin formation and it is possible to apply ß-LGH-Fe complexes as iron-fortified supplements with high iron absorbability.

Preparation and characterization of ß-lactoglobulin hydrolysate-iron complexes.

The purpose of this study was to determine the best preparation condition of ß-lactoglobulin hydrolysate-iron complexes and characterize its structural transformation both before and after binding using the UV-visible absorption spectrum, Fluorescence spectrum, and Fourier transform infrared spectroscopy. Results showed that ß-lactoglobulin hydrolysates obtained with alcalase after hydrolysis for 6h possessed the highest iron-binding capacity. The highest yield of complexes was obtained when the mass ratio between ß-lactoglobulin hydrolysate and Fe(3+) reached 40:1, with the optimal pH value of 7.0. All of the spectra indicated that some sites such as amido bonds transformed during chelation, and nitrogen atoms could chelate with Fe(3+) to form coordinate bonds by offering electron pairs. Therefore, ß-lactoglobulin hydrolysate-iron complexes may be good carriers for iron and possess great potential to be used as iron supplements.