Alginate Sodium

Alginate, sometimes shortened to "algin", is present in the cell walls of brown seaweeds, and it is partly responsible for the flexibility of the seaweed. Consequently, brown seaweeds that grow in more turbulent conditions usually have a higher alginate content than those in calmer waters. While any brown seaweed could be used as a source of alginate, the actual chemical structure of the alginate varies from one genus to another, and similar variability is found in the properties of the alginate that is extracted from the seaweed. Since the main applications of alginate are in thickening aqueous solutions and forming gels, its quality is judged on how well it performs in these uses. A high quality alginate forms strong gels and gives thick aqueous solutions. A good raw material for alginate extraction should also give a high yield of alginate
Alginates from different species of seaweed often have variations in their chemical structure, resulting in different physical properties. For example, some may yield an alginate that gives a strong gel, another a weaker gel; one may readily give a cream/white alginate, another may give that only with difficulty and is best used for technical applications where colour does not matter. There are more reasons why alginate producers prefer to buy a mixture of species of seaweeds, this allows them to blend their products to give properties to suit particular uses. So, price permitting, normally there is a market for any brown seaweed that will yield an alginate of medium to high viscosity or high gel strength.