EXTRACTION AND CHARACTERIZATION OF SODIUM ALGINATE FROM THE MACROALGAE Macrocystis pyrifera

Abstract

In the present work, it was proposal a process for the extraction of sodium alginate, which was obtained from the brown macroalgae Macrocystis pyrifera collected in La Punta-Callao. The extraction process presented a yield of 12 % and the alginate obtained was characterized by FT-IR and 13C NMR techniques in solid state, which was compared with a commercial alginate. The evaluation of the presence of mannuronic and guluronic blocks has been carried out through the use of the 2nd derivative, obtaining characteristic signals at 894 cm-1 for C1-H α – L – guluronic in AlgM and at 885 cm-1 for C1-H anomeric region of the β-D-mannuronic in AlgC. Moreover, characteristic signals were assigned for the algae spectrum at 902 cm-1 and at 812 cm-1 corresponding to vibrations of the α – L – guluronic blocks. By 13C NMR in solid state, a characteristic peak was obtained at 102.4 ppm for AlgM associated with the anomeric carbon C1-H α – L-guluronic, while in AlgC two peaks were visualized at 101.8 ppm and 99.8 ppm assigned to the C1-H α – L – guluronic and C1-H β – D – mannuronic respectively thus indicating the presence of both G blocks and M blocks in commercial alginate.