As you probably guessed, the name of this additive comes from its
marine origin. In fact, sodium alginate is extracted from brown algae
found on the coasts of the North Atlantic, Asia and South America.
Its discovery was made by a chemist named E.C.C. Stanford, who
described the molecule for the first time in 1881.

The food industry uses this algae extract in many different processes
and, depending on the desired properties, manufacturers prefer
several varieties of marine plants (Laminaria hyerborea, Laminaria
digitata, Laminaria japonica, Ascophyllum nodosum, Ecklonia maxima).

Alginate is a polysaccharide, or a sugar chain, from the cell wall
of algae. First extracted in the form of alginic acid, the product is
then neutralized with salts that make it soluble and stable in a
water solution. The solution goes through sifting, centrifuging and
filtration before being precipitated in alginate salt.

Industry takes advantage of many of sodium alginate’s properties.
Its resistance to heat makes it an ingredient of choice in bakeries
to make cream fillings or fruit jellies, allowing them to keep their
shape during cooking. In addition, the thin film created around the
gel or cream prevents it from affecting cake moisture. Its thickening
effect in aqueous solutions is used to create thicker cheese sauces
that adhere better to pasta. Alginate is also used as a stabilizer in ice
cream by decreasing the size of crystals and obtaining a smoother
texture. It also prevents the separation of emulsions such as salad
dressings or mayonnaise. Gels form more easily when alginate is
added to products with higher calcium concentrations.