Effect of Sugars on Gelation Kinetics of Gelatin Gels

We investigate the rheological behavior of aqueous solutions containing animal gelatin, sugars and polyols. The aim is to study how the gelation kinetics, transition temperatures and gel strengths of an aqueous gelatin solution can be affected by the progressive addition of co-solutes. Aqueous solutions with a fixed mass percentage of gelatin of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>6.8</mn></mrow></semantics></math></inline-formula> wt% were prepared at various concentrations of sugars and polyols. Through Dynamic Temperature Ramp tests, performed at various ramp rates, and Dynamic Time Sweep and Dynamic Frequency Sweep tests, carried out at different temperatures, it was possible both to evaluate the transition temperatures and to monitor the gelation kinetics of the samples. It was found that the contribution of co-solutes positively affects both the gelation process and the thermal stability of the aqueous gelatin solution by reducing the gelation time and improving the mechanical properties of the gel in terms of network elasticity.