Red seaweeds contain naturally-occurring polysaccharides which fill the voids within the cellulose structure of the plant. This family of polysaccharides include carrageenan and furcellaran. Gels are produced by heating and cooling solutions of these polysaccharides to give soft, elastic gels with iota carrageenan and firm, brittle gels with kappa carrageenan and furcellaran. Lambda carrageenan gives viscous solutions. Carrageenan is utilised for water dessert gels and glazes, flans, canned meats and pet food. In addition, carrageenan interacts with protein to stabilise, thicken and gel a wide range of products including milk drinks and shakes, ice cream and dairy desserts.