Abstract

The effect of gelation conditions on the gelation of gelatin solutions was studied by rheological measurements. It showed that the gelling temperature (Tgel) increased with the increasing of gelatin concentration. Tgel was also enhanced by the deviation of solution pH from the isoelectric point (IEP) of gelatin. On the contrary, Tgel was reduced by the increasing of ionic strength. In addition, the solvent has a notable influence on the gelation of gelatin. Unlike in urea solution where the formation of hydrogen bonds between gelatin chains was hindered, thereby leading to a decrease of Tgel, in methanol solution the hydrophobicity decreased, and the gelation was facilitated with a high Tgel. Our results demonstrate that polymer gelation depends on gelation conditions and it provides structural insight to improve the design of biopolymer-based gels.