Effects of Cation Properties on Sol-gel Transition and Gel Properties of κ-carrageenan

The phase transition temperatures, rheological properties and gel‐network characteristics for gelation of κ‐carrageenan‐salt (NaCl, KCl and CaCl2) solutions and their aged gels were investigated. The effectiveness of increasing gelling and gel‐melting temperatures at the salt concentrations examined followed the sequence of K+ > Ca2+ > Na+. This sequence was also true for the gel strength and the melting enthalpy (DH) of the most crosslinked junction zones of aged gels at low salt concentrations. Nonetheless, a different order (Ca++ > K+ and Na+) was found for increasing storage modulus and gelation rate during early‐stage gelation, thermal hysteresis and the DH of aged gels in some salt‐carrageenan systems.