Sodium Alginate is a non-digestible, edible carbohydrate derived from brown seaweed. It’s the most common type of alginate found in food and is used by food manufacturers as a thickener, stabiliser, and gelling agent. This component is often used to make heat-resistant gels and to give food viscosity.
Sodium Alginate also helps lower cholesterol, blood sugar, blood pressure, etc.
Sodium Alginate is also known by the name of Algin Gum and Alginic Acid.
Properties
1. Appearance : Filamentous, white to yellowish-brown, powdery or granular, odourless, and tasteless.
2. Structure : Sodium alginate is a polysaccharide polymer composed primarily of L-guluronic acid (G unit) and -D-mannuronic acid (M unit), which are linked together by 14 glycosidic linkages. Its viscosity, gelling capabilities, and gel strength are by the M/G ratio, which is related to the species of seaweed and the harvest season).
3. Solubility : Sodium Alginate gets dissolved in hot or cold water to produce a viscous colloidal solution.
4. Viscosity : Generally, the viscosity depends on:
- Degree of polymerization
- The molecular weight of the sodium alginate polymer
- Temperature
- Concentration
- Presence of polyvalent metal cations
5. pH : In food applications, the pH varies from 4.0 to 10.0.
6. Gelling : Acids or multivalent cations, such as calcium, copper, and lead ions form a heat-stable gel. A calcium salt is commonly used to react with a sodium alginate solution to form a gel in which polymers are cross-linked by calcium ions, such as in the production of jelly.
Uses Of Sodium Alginate
Sodium Alginate has thickening, gelling, and stabilising properties, which is widely used in food, particularly in dairy-based frozen products (e.g., ice creams, yoghurts, puddings, cheese sauce, and desserts).
In the manufacturing industry, Sodium alginate is used as a binding agent in tablets, as a binding and soothing agent in throat lozenges, and as a film in peel-off facial masks.