Sodium Alginate is the sodium salt form of alginic acid and gum mainly extracted from the cell walls of brown algae, with chelating activity.
Alginate is a natural polysaccharide at levels of 30 to 60% in certain species of brown algae (on a dry weight basis). Alginate is considered to have dietary fiber properties. Alginic acid accumulates in brown seaweeds and forms a structural component of the cell walls. This accumulation of alginate also gives flexibility to seaweed and allows the seaweed to withstand tidal forces. Alginic acid was first isolated and named by a Scottish scientist, Dr. E.C.C. Stanford, in1883. Since then, alginic acid and its derivatives have been utilized as a hydrocolloid in a variety of applications such as food additives, pharmaceuticals, cosmetics and textile printing.
Functional uses: Stabilizer, thickener, gelling agent, emulsifier.
| Appearance | White to yellowish brown filamentous, grainy, granular or powdered forms |
| Chemical formula | (C6H7NaO6)n or C6H9NaO7 |
| Loss on drying | Not more than 15 % (105 °C, 4 hours) |
| Formaldehyde | Not more than 50 mg/kg |
| Arsenic | Not more than 3 mg/kg |
| Lead | Not more than 5 mg/kg |
| Mercury | Not more than 1 mg/kg |
| Cadmium | Not more than 1 mg/kg |
| PH | 6.5-7.5 |
| Assay (on dry basis) | ≥ 98% |