What is Sodium Alginate?
The chemical compound sodium alginate is the sodium salt of alginic acid. Sodium alginate is a gum, extracted from the cell walls of brown algae of the Laminaria species, with an alkaline solution. He called this product “Algin”, a term still commonly used to describe sodium alginate. The seaweed is dried, cleaned, boiled, gelled and ground into powder. The powder has a light yellow appearance. As a flavorless gum, it is used by the food industry to increase viscosity and as an emulsifier.
What Does Sodium Alginate Do?
As a food additive, sodium alginate is used especially in the production of gel-like foods. For example, bakers’ “Chellies” are often gelled alginate “jam.”
When dissolved in liquids, sodium alginate acts as a thickener, creating a viscous fluid.
Conversely, when sodium alginate is used with calcium it forms a gel through a cold process. This gelling occurs through a cold process, as opposed to the formation of agar agar gels.
Why Use Sodium Alginate in Molecular Gastronomy?
In molecular gastronomy, sodium alginate is most commonly used as a texturising agent. Foams and sauces may be created with use of this. It is also used in spherification for the creation of pearls, raviolis, mock caviar, marbles and spheres. It is also used for making foams and thickening sauces.
For direct spherification – sodium alginate is added to the food that is being spherified. The droplets of food are then dropped into a calcium bath.
For reverse spherification – sodium alginate is added to the bath in which calcium rich food is spherified.
Sodium alginate is easy to use and sets at any temperature and is soluble in hot and cold water. When mixed with calcium compounds does not need heat to gel.