Preparation and characterization of β-lactoglobulin hydrolysate-iron complexes

The purpose of this study was to determine the best preparation condition of β-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 β-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 β-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, β-lactoglobulin hydrolysate-iron complexes may be good carriers for iron and possess great potential to be used as iron supplements.