Carrageenan is a sulfated polysaccharide extracted from species of red algae, including Gigartina skottsbergii, Chondrus crispus and Eucheuma cottonii. The solubility and gelling capability of carrageenans differ depending on the type of red algae used. Carrageenan has been used for hundreds of years as a food additive. In foods, it acts as a thickener and stabilizer 1. Carrageenan is approved for use as a food additive by the U.S. Food and Drug Administration (FDA) 2.