sodium alginate chemical properties

Social Share Toolbar

sodium alginate properties


NAME: Sodium alginate

FUNCTIONAL USES:Stabilizer, thickener, gelling agent, emulsifier

sodium alginate molecular weight:10,000 – 600,000 (typical average)

sodium alginate cas: 9005-38-3

sodium alginate boiling point:495.2°C at 760 mmHg

DESCRIPTION:Occurs as white to yellowish brown filamentous, grainy, granular or powdered forms

sodium alginate structure

   sodium alginate formula:

Structural formula from Phillips, Wedlock and Williams: Gums and Stabilizers for the Food Industry 5 (1990) by permission of Oxford University Press.

   The number and sequence of the Mannuronate and Glucuronate residues shown above vary in the naturally occurring alginate. The water molecules associated with the alginate molecule are not shown in the above structural formula.

         sodium alginate molecular structure

            sodium alginate ph:

Sodium alginate is slightly soluble in water but insoluble in most organic solvent. The sodium alginate powder will get wet when exposed to moisture and combination of the powder and water will make the surface be sticky. Such stickiness will make the powder become clumps and the dissolve of such clumps will be slow. The content of sugar, starch or protein can decrease the dissolve of sodium alginate. Monovalent cation such as NaCl could show similar performance when the content is over 0.5%.PH of sodium alginate dissolved in 1% distilled water is about 7.2


Sodium alginate is hygroscopic and the content of water depends on the relative humidity. Dried sodium alginate is quite stable when stored in well sealed container under temperature no higher than 25 ℃.Its solution is stable at PH 5~9. Stickiness of sodium alginate solution is affected by degree of polymerization (DP) and the molecular. Decrease of stickiness could indicate the decrease of degree of polymerization (DP).High degree of DP is less stable than the product of low DP. It is reported that sodium alginate could be hydrolyzed and the hydrolyzation depends on time,PH and temperature. Solution of propylene glycol alginate is stable under room temperature and PH of 3~4; when the PH is lower than 2 or higher than 6, the stickiness would decrease quickly even under room temperature.

On September 8th, 2012, posted in: NEWS by

Comments are closed.