Preparation and structure characterization of whey polypeptide chelating calcium

The combination between whey polypeptide and calcium ion was studied based on the preparation of whey polypeptide from whey protein.Calcium ion content and chelating rate were taken as the indexes to optimize the chelating condition :mass ratio of whey polypeptide and calcium salt 1 ∶5, initial pH of peptide solution 10.5, reaction temperature 65℃ and reaction time 50min.Calcium ion content in product was 10.5%± 0.5%.The product structure was characterized by Uv-Vis spectroscopy, Fourier transform infrared spectroscopy and Scanning electron microscopy.It included coordination reaction between calcium ion and carboxyl/amino group of whey peptide occurred.