Binding of galactomannans to kappa-carrageenan after cold mixing

The room temperature interaction between swollen carrageenan particles and solutions of carob, cassia, guar, and tara galactomannans has been studied. Analysis using gel permeation chromatography of the supernatant solution above the carrageenan particles demonstrated binding of all the galactomannans, except guar, to kappa-carrageenan. It was also demonstrated that carob galactomannan did not bind to iota-carrageenan. Binding after cold mixing saturates at high kappa-carrageenan/carob ratios, of the order of 80, unlike the interaction in mixtures after heating, which saturates at ratios close to 1. The existence of binding shows that the interaction between these two species is attractive, and thus suggests that the synergistic rheological interaction which occurs after heating is due to the formation of mixed junction zones.