We studied the impact of anionic polysaccharide (k-carrageenan) as a co-gelator of gelatin at different
physico-chemical and by varying thek-carrageenan/gelatin ratio. It has been shown that increasing
kcarrageenan concentration accelerates the gelation and leads to significant increase in the viscoelastic
parameters of the modified gels. Non-linearity of viscoelastic properties becomes evident in much lower
deformations in comparison with those of native gelatin gels. The strength of gels characterized by the
yield stress also increases along with k-carrageenan concentration. The deformation (but notflow) of
gels happens along the rupture surfaces appearing at the apparent yield stress. The melting temperature
increases until 45C for high k-carrageenan/gelatin ratio. The suggested explanation of the observed
changes in properties of modified gels relates these effects with formation of complexes of gelatin and
polysaccharide. FT-IR spectroscopy data show that (bio)polyelectrolyte complex formation is due to
electrostatic interaction between positively charged groups in gelatin and negatively charged sulfate
groups in k-carrageenan that leads to conformation changes of gelatin macromolecules. Micrographs
(scanning electron microscopy) show that addition of even a small quantity of polysaccharide leads to
radical changes in supramolecular structure of modified gels.