Carrageenan is a common name for a family of gel-forming and viscosifying polysaccharides which are extracted from various species of seaweeds, especially red seaweed.
A variety of plants (different species in different locations) have been known for these characteristics. For example, off the Atlantic coastlines of Europe & North America, ‘Irish Moss’ has been prized for carrageenan. In South America & around Japan, we talk about ‘Sea Chicory/yanaginori’; whilst in the Pacific Islands, Indonesia and Philippines, ‘Coral grass’ is popular. These plants all belong to the red seaweed group and, more specifically, the order of ‘Gigartinales‘.
What these plants have in common is that they contain carrageenan, a polysaccharide with viscosity & jelly-like characteristics. Carageenan is made up of cellulose and sulfated polygalactan with 15% to 40% of ester-sulfate content. Carageenan has an off-white to brown appearance and is commercially available in powdered form, also sometimes referred to as ‘seaweed flour’. Different grades are produced with different processes and as a result, final products can differ in their chemical structure and properties, and therefore have different uses or applications.
There is commercial interest in the compounds of three different grades: Iota (ι), kappa (κ), and lambda (λ). These are largely used as gelling agents in the food and beverage industry. Carageenan (the extract) obtained approval from the European Union as a food additive with E-number E407 and is primarily used in pet food, meat & processed food, dairy, air fresheners, pharmaceutical and beverage industries. The dairy industry also uses carrageenan gum because it prevents the separation of fat from protein so is a great substitute for gelatin jellies in water-based foods.
Because Carrageenan gum is obtained from seaweed it has never been suspected of having a negative effect on health. However, rising concern over gastrointestinal and inflammatory disorders among consumers has significantly hampered the carrageenan market. Read more about the controversy.