Gelation kinetics of aqueous gelatin solutions in isothermal conditions via rheological tools

We investigate the sol-gel transition of aqueous pig-skin gelatin solutions at different concentrations and temperatures. In particular, we characterize the isothermal gelation kinetics close to the critical melting temperature, previously evaluated with dynamic temperature ramp tests. The time evolution of the moduli is analyzed at a specific fixed frequency and at various temperatures and concentrations. The isothermal study allows to evaluate the gel time and to determine its dependence on concentration and temperature. The study of the gelation kinetics over a wide range of concentrations allows to link the behavior in solution to the gelation phenomenon, confirming a different temperature dependence of the sol-gel transition according to the concentration regime Although some models are available to describe this dependence, they do not simultaneously account for the effect of both parameters (i.e. temperature and concentration). Here, we propose a full empirical model that accommodates the dependence upon both temperature and concentration.