Novel procedures for the extraction of fucoidan from brown algae

Sulfated polysaccharides, such as the so-called fucoidans, from brown algae exhibit a versatile biological activity, which is thought to be associated with their characteristic sulfated fucose backbone. The extraction of the target compound is one of the most important steps of the purification process. The correct adjustment of parameters, such as temperature, pH, and extraction time, greatly influences the yield and prevents the possible structural alteration of the sulfated polysaccharides. This review includes historical and current extraction procedures for sulfated polysaccharides and illustrates novel extraction techniques, which can effectively improve the extraction process. The use of ultrasound- and microwave-assisted extraction techniques is described, the potential of which has been underestimated to date. Furthermore, the enzyme-assisted extraction of fucoidans is in its infancy. It is assumed that further improvements of these procedures (e.g., by the application of computer-aided techniques) will have a major impact on the economics and the scalability of the extraction process as well as yielding a sugar fraction with a conserved sulfation pattern.