Polysaccharides are the most abundant macromolecules on Earth and in the oceans. These macromolecules are the major structural elements of plant walls (e.g. cellulose, carrageenans, alginates) and may be involved in plant/pathogen recognition mechanisms. They also play an essential role in energy storage (e.g. starch, laminarin). Polysaccharides are solid substrates in the form of fibers, granules or gels, whose physico-chemical and structural properties are intimately linked to their chemical structures and, consequently, to their biosynthesis.
Polysaccharides are widely used in the food and pharmaceutical industries for their technological, physiological and pharmaceutical properties, and are major players in the global economy.
Polysaccharides are classified into three subgroups: amylaceous, non-amylaceous and polysaccharide-type polyols.
The structures of the various purified fractions are determined by chemical characterization methods. Firstly, the monosaccharide composition of the samples is determined after degradation of these polysaccharides by acid or enzymatic hydrolysis. The hydrolysate is then characterized by gas chromatography after derivatization (silylation or acetylation) or by HPLC (high-performance liquid chromatography).