Semi-refined carrageenan is washed and alkali treated seaweed. The carrageenan is not extracted out of the seaweed but is still contained in the cell wall matrix. Commercial carrageenan products are frequently standardized for obtaining optimal gelling and thickening properties. By using the appropriate carrageenan product, the formulator can create textures ranging from free-flowing liquids to solid gels. In addition to offering standard types, Foodchem works in conjunction with customers to develop new products and formulations for specific applications.
Carrageenans are large, highly flexible molecules that curl forming helical structures. This gives them the ability to form a variety of different gels at room temperature. They are widely used in the food and other industries as thickening and stabilizing agents. A particular advantage is that they are pseudoplastic—they thin under shear stress and recover their viscosity once the stress is removed. This means that they are easy to pump, but stiffen again afterward.
All carrageenans are high-molecular-weight polysaccharides made up of repeating galactose units and 3,6 anhydrogalactose (3,6-AG), both sulfated and nonsulfated. The units are joined by alternating alpha 1–3 and beta 1–4 glycosidic linkages.
