Properties of Sodium Alginate

Properties of Sodium Alginate

1. Thickening Property of Alginates

As a hydrophilic polymer, alginates have one important feature, that is, its solution has relatively high viscosity. Based on this, alginates can act as thickening and tackifying agents. The larger the molecular weight is, the higher the solution viscosity becomes and the better the thickening effects get.


2. Gelling Property of Alginates

Of the alginate application, the application of gelling property is wider. Water-soluble alginates can generate a chemical reaction with calcium ions and soon form gel. Almost all alginates can gelate, but in practice only sodium alginate, potassium alginate and ammonium alginate are usually used. One method of increasing the gel strength of alginates is to boost the concentration of alginates and calcium ions and reduce the system temperature (such as cooling).


3. Film-Forming Property

Alginates have favorable film-forming properties. The thin layer in the alginate solution can eliminate the thin film of moisture by evaporation and is impermeable to oil and fat but can help them to redissolve in water by water vapor. The thin film of alginates is relatively fragile in the dry condition but propylene glycol can be used to plastify. Usually, alginates with relatively low molecular weight and low calcium content are used because they can make preferable thin films. This property is often used in vegetable preservation.


4. Lipophilicity

Lipophilicity of propylene glycol alginate solution can effectively be used as a stabilizing agent of cream, syrup, beer, beverages and salad oil.

When lipophilicity of propylene glycol alginate is used, products of high esterification degree should be chosen because the higher the esterification degree is, the stronger the lipophilicity and the surface activity of propylene glycol alginate are. In addition, low-viscosity products should be chosen as possible.

The beer foam stabilizer is a typical application of high esterification degree propylene glycol alginate solution and its general dosage is 40-100mg/kg. Especially when there exists fatty substance, propylene glycol alginate helps to prevent the phenomenon of bubble burst.

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On April 8th, 2013, posted in: Products and Techniques, Sodium Alginate by Tags:

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