Cation effect on gel-sol transition of kappa carrageenan

Abstract

The steady state fluorescence (SSF) technique was employed to study gel - sol transitions of kappa carrageenan in NaCl, KCl and CaCl2 solutions. Pyranine was used as a fluorescence probe for monitoring these transitions. Scattered light, I-sc and fluorescence intensity, I was monitored against temperature to determine the gel - sol (T-gs) transition temperatures and exponents. It was observed that T-gs values are strongly correlated to the NaCl, KCl and CaCl2 contents. The weight average degree of polymerization, DPw and gel fraction G, exponents (gamma and beta) were measured and found to be in accord with the classical Flory-Stockmayer Model.