Calcium-induced gelation of low methoxy pectin solutions--thermodynamic and rheological considerations.

Rheological changes occurring during the gelation of low methoxy pectins in the presence of calcium ions were investigated. The onset of gelation was found to correspond to the same macroscopic rheology (i.e. value of G') whatever the gelling conditions. Sol-gel diagrams for calcium pectin systems were mapped out in terms of calcium level, temperature and pectin concentration. The thermodynamic parameters for the cross-linking process were derived.