Synthèse bibliographique sur la valorisation des algues rouges « méthodes de fabrication d’Agar-agar »

Abstract

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.