ABSTRACT
Alginates are anionic polysaccharides. It is a linear copolymer of (1 → 4) linked β-d-mannuronic acid (M) and α-l-guluronic acid (G) residues with widely varying compositions and sequences. The distribution of M and G in alginate chains gives rise to three different block types: blocks of poly-M, blocks of poly-G, and alternating MG blocks. While the M-block segments develop in linear and exible structures, the G-block residues give rise to fold and rigid structures. Alginates can be identied using IR, Raman, and NIR spectroscopies. More detailed information about the structure is now available with the introduction of high-resolution 1H and 13C NMR spectroscopy in the sequential analysis of alginate (Larsen et al. 2003; Pereira et al. 2003; Leal et al. 2008; Campos-Vallette et al. 2009).
