Hysteresis during sol-gel and gel-sol phase transititons of k-carrageenan: A photon transmission study.

Photon transmission techniques were used to study sol-gel and gel-sol transitions in k-carrageenan-water systems with various carrageenan contents. The photon transmission intensity, Itr was monitored against temperature to determine critical phase transition temperatures and transition rates. It was observed that the sol-gel transition temperatures, Tsg, were found much lower than the gel-sol, Tgs, transition temperatures based on the hysteresis of the phase transition loops. Sol-gel and gel-sol activation energies were determined and it was found that a carrageenan-water system required less energy for the gel-sol transition than for the sol-gel transition.