Sodium alginate, also known as sodium alginate, is a natural polysaccharide extracted from the cell walls of brown algae such as kelp and giant kelp. Essentially a linear natural polymer, it is a byproduct of the extraction of iodine and mannitol from kelp or Sargassum fusiforme.
Its molecule is composed of β-D-mannuronic acid (M) and α-L-guluronic acid (G) linked by (1→4) bonds. Sodium alginate aqueous solutions have high viscosity and have been used as thickeners, stabilizers, and emulsifiers in food. Sodium alginate is a non-toxic food and was included in the United States Pharmacopeia as early as 1938. In the United States, it is hailed as a "miracle food additive"; in Japan, it is known as a "longevity food." Sodium alginate has been widely used in the food industry and the pharmaceutical field. Commercially available alginate products mainly include water-soluble sodium alginate, potassium alginate, ammonium alginate, and propylene glycol alginate obtained through chemical modification.
