Mixed iota-kappa carrageenan gels

Studies have been made of the gelation of mixtures of iota and kappa carrageenan. Differential scanning calorimetry (DSC) studies suggest that the iota and kappa components gel independently of each other. The DSC data conflict with evidence presented for the currently accepted Domain model for carrageenan gelation (Morris, E.R., Rees, D.A. and Robinson, G.J. J. Mol. Biol. 1980; 138: 349). In particular, the present data suggest that iota carrageenan gels show thermoreversible setting and melting behaviour associated with the coil-helix transition. Analysis of rheological data favours an interpenetrating network (IPN) model for gelation of the mixtures.