The sol-gel transition of agar, κ-carrageenan and gellan gum in the presence of sodium chloride were investigated by thermal and rheological measurements. The G′, G″ and DSC curves for the agar solution during cooling and heating were slightly affected by added sodium chloride. In respect of the κ-carrageenan and gellan gum solutions, G′ and G″ were increased, and DSC curve shifted to a higher temperature in the presence of sodium chloride. The rheological and thermal behavior in the presence of sodium chloride may have been affected not only by the change density of molecules but also by the gelation mechanism, since gelation of the gellan gum sol was much more accelerated than the κ-carrageenan.
