Sodium Alginate, also called algin or alginate, is an anionic polysaccharide distributed widely in the cell walls of brown algae, where it, through binding water, forms a viscous gum. In extracted form it absorbs water quickly; it is capable of absorbing 200-300 times its own weight in water. Its colour ranges from white to yellowish-brown. It is sold in filamentous, granular or powdered forms.
Its form as a flavorless gum, is used by the foods industry to increase viscosity and as an emulsifier. It is also used in indigestion tablets and the preparation of dental impressions.
A major application for Sodium Alginate is in reactive dye printing, as as thickener for reactive dyestuffs (such as the Procion cotton-reactive dyes) in textile screen-printing and carpet jet-printing. Sodium Alginate does not react with these dyes and wash out easily, unlike starch-based thickeners.
Sodium Alginate is a good chelator for pulling radioactive toxins from the body, such as iodine-131 and strontium-90 that have taken the place of their non-radioactive counterparts. It is also used in immobilizing enzymes by inclusion.
As a food additive, Sodium Alginate is used especially in the production of gel-like foods. Also, the pimento stuffing in prepared cocktail olives is usually injected as a slurry at the same time that the stone is ejected; the slurry is subsequently set by immersing the olive in a solution of a calcium salt, which causes rapid gelation by electrostatic cross-linking. A similar process can be used to make "chunks" of everything from cat food through "reformed" ham or fish to "fruit" pieces for pies. It has the E-number 401.
Nowadays, it is also used in the biological experiments for the immobilization of cells to obtain important products like alcohols, organic acids, etc. |