Gel-sol-gel transition of kappa-carrageenan and methylcellulose binary systems studied by differential scanning calorimetry

Kappa-carrageenan (kappa C) was mixed with methylcellulose (MC) with various mixing ratios. Phase transition behaviour of the above mixed solutions with 1 and 2% concentration was investigated by visual observation and differential scanning calorimetry (DSC). Three regimes showing unique transition behaviour were observed: Regime I which is an MC rich region where only sol-gel transition is found, Regime II an intermediate mixing range of kappa C and MC where sinusoidal change of gel-sol-gel transition was observed, and Regime III a kappa C rich region where only gel-sol transition was detected. A phase diagram of kappa C/MC binary systems was established based on transition temperatures obtained by visual observation and DSC. (C) 2014 Elsevier B.V. All rights reserved.