iotacarrageenan

Iota-carrageenan is a sulfated polysaccharide in the carrageenan family derived from red seaweeds. It is one of several related polysaccharides (including kappa- and lambda-carrageenan) distinguished by sulfate patterns and gelling behavior. Iota-carrageenan is typically extracted from species of red seaweed such as Hypnea and Gigartina and processed into food-grade or pharmaceutical-grade carrageenan for use as a thickener, stabilizer, and gelling agent.

In solution, iota-carrageenan carries multiple sulfate groups, giving it a strong negative charge. It forms gels in the presence of calcium ions, producing soft, elastic gels whose strength can be influenced by ion concentration, temperature, and other formulation factors. The polymer is noted for stability under freeze–thaw cycles, a property valued in frozen desserts and similar products.

Applications of iota-carrageenan span food, cosmetics, and pharmaceuticals. In the food industry, it is used to improve texture and stability in dairy products, yogurt, ice cream, plant-based milk alternatives, sauces, and processed meats. In cosmetics and personal care, it serves as a thickener and stabilizer. In pharmaceutical contexts, it can act as a gelling or thickening excipient and may influence drug delivery in certain formulations. Iota-carrageenan has also been investigated for antiviral properties, with nasal sprays containing iota-carrageenan marketed and some clinical studies suggesting potential benefits in reducing symptoms or duration of viral infections in specific populations; however, results are mixed and not universally established.

Safety and regulation: In foods, iota-carrageenan is approved as a food additive (often listed as E407) in many jurisdictions, with use levels defined by regulation. Degraded carrageenan (poligeenan) is not approved for ingestion due to safety concerns. Regulatory assessments generally regard food-grade iota-carrageenan as safe at approved levels, though some individuals may experience gastrointestinal discomfort or sensitivities at high intakes.