The effect of temperature and composition on the interfacial tension and rheology of separated phases in gelatin/pullulan mixtures

It was found that above gelling temperature the gelatin rich phase is approximately Newtonian but as the temperature approaches gelation point it becomes strongly non-Newtonian, with G′ and G″ being time dependent. The pullulan rich phase is also approximately Newtonian at low shear rates and becomes non-Newtonian at a higher shear rate and high concentrations. Above gelling temperature the interfacial tension increases with total concentration of polymers, or in other words with length of tie-lines and at each tie-line it is temperature independent. As the temperature approaches gelation point the interfacial tension for a given mixture decreases sharply.