Alginate is a fiber-type carbohydrate extracted from brown algae (Macrocrystis, Fucus, Laminaria) from cold seas. Its main function is to act as a gelling agent in the presence of calcium, although it also functions as a thickener and stabilizer.
It forms a thermostable gel that does not become liquid when heated.
Hydrocolloid polysaccharide, very useful in technical culinary applications.