Furcellaran

Furcellaran is a sulfated galactan polysaccharide isolated from certain red algae, especially Furcellaria lumbricalis, and is used commercially as a gelling agent and thickener. It belongs to the carrageenan family, being closely related to kappa- and iota-carrageenans, though it is chemically distinct in sulfation pattern and chain structure.

Chemically, furcellaran comprises repeating disaccharide units of galactose and 3,6-anhydrogalactose with sulfate groups. Its exact sulfation pattern gives it a gelling behavior that is intermediate between kappa- and lambda-type carrageenans, often requiring specific ions (notably potassium) to gel, and producing thermo-reversible gels.

Manufacture: It is obtained from red seaweeds by alkaline extraction, purification, and precipitation. The Baltic Sea species Furcellaria lumbricalis is one of the traditional sources.

Applications: In the food industry, furcellaran acts as a gelling agent, thickener, and stabilizer in dairy desserts, fillings, jellies, and processed meats; it is also used in cosmetics and pharmaceutical formulations. Its rheology can be tailored by ion content and formulation with other polysaccharides or proteins.

Regulation and safety: Furcellaran is used under food additive approvals in some markets. As with other carrageenan-type galactans, its acceptance varies by jurisdiction and application; typical usage levels are within established limits to avoid textural issues. Researchers study its properties for potential alternative gelling systems.