LAUSR

Abstract The effect of different counterions (Na+, K+ and Ca2+) on the sol-gel transition diagrams of kappa/iota-hybrid carrageenan isolated from Gigartina skottsbergii, together with the thermo-rheological features of the obtained gels are presented. Extraction yield (47.8 ± 3.5 g/100 g), molar fractions of kappa (62 ± 2) and iota (38 ± 2) and polymers with molecular masses between 7.5 104 and 7 103 g/mol were also determined for G. skottsbergii extracts. Gels formed in NaCl exhibited stable and weak gel properties. Gels made in KCl and CaCl2 featured stable and intermediate gel characteristics, except those formulated at the largest carrageenan and salt content that can be considered strong. All gels achieved stability after 15 min of maturation. No water syneresis was identified in tested gels. Gel setting and melting temperatures depended on the biopolymer and ionic contents. Gels formed in CaCl2 at the largest biopolymer content and ionic concentration showed thermo-reversible features.