carrageenan

Carrageenan is a family of sulfated polysaccharides derived from red seaweeds, notably Chondrus crispus (Irish moss) and various Eucheuma species. It is widely used as a thickener, gelling agent, and stabilizer in food products and in some cosmetic and pharmaceutical preparations. Carrageenan sold for food use is typically categorized into three main types—kappa (κ), iota (ι), and lambda (λ)—which differ in their gelling behavior and properties.

Chemically, these carrageenans are linear chains of galactose units with varying degrees of ester sulfate. κ-carrageenan forms rigid gels in the presence of potassium ions; ι-carrageenan forms softer, elastic gels with calcium ions; λ-carrageenan does not gel but increases viscosity, acting mainly as a thickener. The gel properties are thus influenced by the carrageenan type, ionic conditions, and temperature.

Production involves extracting carrageenan from red seaweeds with hot water, followed by purification, concentration, and precipitation to yield the final product. The resulting material is then dried and milled into powders or used in liquid form. In commerce, carrageenan is also identified as E407 in many regions.

Uses are extensive and include dairy and dairy-alternative products (milk, yogurt, cheese analogs, ice creams), desserts, processed meats, sauces, and dressings. It is also employed in some personal care products, pharmaceuticals, and pet foods to improve texture and stability.

Safety and regulation: carrageenan is approved for use as a food additive in many jurisdictions. In the United States it is permitted as a direct food additive; in the European Union it is labeled E407. Regulatory bodies including the FDA and EFSA have assessed carrageenan as safe at approved exposure levels. Degraded carrageenan, known as poligeenan, is not permitted for foods. Some studies have discussed potential inflammatory effects in animals, but human data do not establish a clear causal risk at typical dietary intakes.