Infood systems, one of the most important properties that trulydifferentiates carrageenan from other hydrocolloids is its ability tocomplex or interact with proteins. In milk protein systems, atperipheral locations on the casein micelle there is a concentration ofpositive charges. This positive electrostatic charge attracts thenegatively-charged sulfate groups of the carrageenan molecule to formlinkages among the dispersed casein micelles as illustrated in Figure 14 .This reaction, in combination with the normal water gellingcapabilities of carrageenan can increase the gel strength about 10-fold.

Carrageenan’s ability to complex with milk proteins,combined with its water gelling properties enhances carrageenan’sfunctionality, e.g. increased gel potential. For this reasoncarrageenan will form a weak thixotropic gel structure which willsuspend cocoa in chocolate milk at 0.02% and form milk gels, such asflans, at 0.20%.