carragenan

Carragenan, also spelled carrageenan, is a family of linear sulfated polysaccharides derived mainly from red seaweeds (Rhodophyta), including species such as Chondrus and Eucheuma. It is used as a thickening, gelling, and stabilizing agent in a wide range of products, from foods and beverages to cosmetics and pharmaceuticals.

Commercial carrageenans are typically sold as kappa-, iota-, or lambda-carrageenan. Kappa forms rigid gels in the presence of potassium ions; iota forms soft, elastic gels with calcium; lambda does not gel but provides thickening and viscosity enhancement. The gelation behavior and texture depend on sulfate content and the presence of 3,6-anhydrogalactose residues.

Production involves extracting the polysaccharide from seaweed with hot alkaline treatment, followed by purification and drying. Refined carrageenan has reduced protein and ash levels and is supplied in refined, semi-refined, or semi-synthetic forms. It is commonly used alone or with other gums to tailor texture in various applications.

Applications are widespread in the food industry, where carrageenan improves mouthfeel, stabilizes dairy emulsions (such as milk, yogurt, and puddings), and prevents separation in beverages and processed meats. It is also used in cosmetics, personal care products, and some pharmaceutical suspensions and tablet formulations.

Safety and regulation: Food-grade carrageenan is generally considered safe at approved usage levels by major regulatory bodies, though there has been debate about degraded forms (poligeenan), which are not permitted in foods. Ongoing reviews continue to assess potential health effects, and labeling and usage limits vary by jurisdiction.