Procédé d'extrusion réactive et/ou enzymatique pour l'extraction de phycocolloïdes : application aux produits de la mer

In this paper we present the reactive extrusion process to extract the phycocolloids from the sea products. By comparing with other techniques, this process has a several advantages like the economic return, the flexibility, the production of various products with different characteristics and time gains. There are two types of extruder: single-screw and double-screw, each one has its specific properties. The solid products are introduced by means of the hopper that is equipped with a dosage pump for the regulation of the flow. Liquid products are, generally, injected in the not filled zones, through an external pump. The products undergo thermo mechanical modifications and then the shaping of the final products was done in the die. The reactive extrusion is applied in several fields: agri-food where there are three main types of operating conditions (simple extrusion, extrusion-cooking, reactive extrusion), in the plastic industry for the recycling of household plastic waste and also to create mixtures between different polymers, as well in the field of chemistry and pharmaceutics. The reactive extrusion is used also to add value to the sea products like to extract phycocolloids especially the alginate from the seaweeds, also the chitin from crustacean by-product. A further interesting application of the reactive extrusion process is the energy production. Recent research is aimed to the valorization of fish by-products for the extraction of lipids for biofuel purpose.