Carageenan is a long chain polysacharide with a backbone of the sugar galactose.
Carageenan is widely used in dairy products because it forms complexes with calcium and milk proteins. It thickens and helps suspend cocoa particles in chocolate milk. It stabilizes ice cream to protect it from thawing and refreezing, and enables it to hold more air.
It is used in flans and custards to thicken them, as well as in puddings. It helps to keep whipped toppings foamy, and it thickens diet shakes and instant breakfast drinks.
It is also used as a dough conditioner in breads and pastries.