Résumé:
Algae are found in coastal waters all around the globe. They can be marine or freshwater, but
the majority of them are marine. It is also important to note that freshwater species are exclusively
green algae. There are three main categories: Pheophyceae (brown algae), Rhodophyceae (red
algae) and chlorophyceae (green algae). The latter contain polysaccharides present at the level of
the wall. The agars and carrageenans extracted from the Rhodophyceae, the alginates and fucans of
the Pheophyceae and the ulvanes of the green algae etc... Most commonly used are agar (E406),
carrageenan (E407) and alginates (E400-405), which are recognized as food additives in the texture
agent category. These polysaccharides have gelling, stabilizing and thickening properties, hence
their application in various industries such as agro-food. They play a very important role in the
manufacture of dairy desserts, gelled confectionery but also as a coating agent for meat and fish... In
pharmacies, polysaccharides are used as excipients in the design of certain drugs and sometimes
even as an active ingredient (in syrups that relieve gastrointestinal reflux) They are also used in
textiles and other industries. Apart from the industrial application, macro-algae are also used in
human food (especially in Asian countries), livestock but also in agriculture as fertilizer. Thus, at
the global level, algae cultivation is growing rapidly.
