Carrageenan With Dextrose
Carrageenans or carrageenins are a family of linear sulphated polysaccharides extracted from red seaweeds. The name is derived from a type of seaweed that is abundant along the Irish coastline. Gelatinous extracts of the Chondrus crispus seaweed have been used as food additives for hundreds of years, though analysis of carrageenan safety as an additive continues Carrageenans are large, highly flexible molecules which 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 pseudoplasticâ€”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 afterwards. There are three main commercial classes of carrageenan: Kappa: strong, rigid gels. Produced from Kappaphycus cottonii Iota: soft gels. Produced from Eucheuma spinosum Lambda: form gels when mixed with proteins rather than water, used to thicken dairy products. The most common source is Gigartina from Southern Europe. Many red algal species produce different types of carrageenans during their developmental history. For instance, the genus Gigartina produces mainly Kappa carrageenans during its gametophytic stage, and Lambda carrageenans during its sporophytic stage. See Alternation of generations. All are soluble in hot water, but in cold water only the Lambda form (and the sodium salts of the other two) are soluble. When used in food products, carrageenan has the EU additive E-number E407 or E407a when present as "Processed eucheuma seaweed". Although introduced on an industrial scale in the 1930s, the first use was in China around 600 BC (where Gigartina was used) and in Ireland around 400 AD. The largest producer is the Philippines, where cultivated seaweed produces about 80% of the world supply. The most commonly used are Cottonii (Kappaphycus alvarezii, K.striatum) and Spinosum (Eucheuma denticulatum), which together provide about three quarters of the world production. These grow at sea level down to about 2 metres. The seaweed is normally grown on nylon lines strung between bamboo floats and harvested after three months or so when each plant weighs around 1 kg. The Cottonii variety has been reclassified as Kappaphycus cottonii by Maxwell Doty (1988), thereby introducing the genus Kappaphycus, on the basis of the phycocolloids produced (namely kappa carrageenan). After harvest, the seaweed is dried, baled, and sent to the carrageenan manufacturer. There the seaweed is ground, sifted to remove impurities such as sand, and washed thoroughly. After treatment with hot alkali solution (e.g. 5-8% potassium hydroxide), the cellulose is removed from the carrageenan by centrifugation and filtration. The resulting carrageenan solution is then concentrated by evaporation. It is dried and ground to specification.