Interaction of gelatin with chitosan: the influence of polysaccharide concentration

The interaction of gelatin and cationic polysaccharide chitosan with stoichiometric (bio)polyelectrolyte complexes formation inside the aqueous phase which pH is less than the isoelectric point of gelatin has been studied by capillary viscosimetry, UV spectroscopy and dispersion of light scattering methods. The aqueous dispersions of complexes show increase in the particle size of disperse phase and accordingly the relative viscosity compared with sols of the individual components - gelatin and polysaccharide. The models and mechanism of (bio)polyelectrolyte complexes formation have been discussed. The formation takes place due to the electrostatic interactions between the positive charged amino groups of chitosan and negative charged aminoacid’s residues (glutamic Glu and aspartic Asp acids) of gelatin.