What You Need to Know
Carrageenan, a sulfated polysaccharide extracted from red seaweed, can be thermally solubilized and then cooled to create a viscoelastic matrix that traps air, forming stable foams. The balance of temperature, pH, ionic strength, and shear determines foam stability, while deviations cause collapse or graininess. Its sulfate groups confer negative charge, promoting electrostatic repulsion between polymer chains and stabilizing the air–water interface.
The Science
Primary Reaction
Thermal solubilization and subsequent cooling of carrageenan leads to viscoelastic network formation that stabilizes air bubbles.