Rheology and fracture of mixed ι- and κ-carrageenan gels: Two-step gelation

摘要: Abstract It is shown that under certain circumstances, on cooling mixed ι- and κ-carrageenan solutions, the two forms gel separately at different temperatures, with ι form gelling first. This ‘two-step gelation’ was only observed when both sodium potassium ions were present, a sodium/potassium mole ratio of between 1 100. For such gels, κ fraction as low 2·5% total carrageenan has significant effects their rheology, deformation fracture. In these systems, form, in presence an existing gel, produces measurable rheological much lower concentrations than if it alone. behaviour can be used sensitive test ‘rheological purity’ samples ι-carrageenan.