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|Title in Portuguese:||Extraction and physicochemical characterization of Sargassum vulgare alginate from Brazil|
|Author:||Torres, Marcia R.|
Sousa, Alessandra P. A.
Silva Filho, Eduardo
Melo, Dirce F.
Feitosa, Judith P. A.
Paula, Regina C. M. de
Lima, Maria G. S.
Espectroscopia de Ressonância Magnética
|Citation:||TORRES, M. R. et al. Extraction and Physicochemical characterization of Sargassum vulgare alginate from Brazil. Carboidrato Research, v. 342, n. 14, p. 2067-2074, out. 2007.|
|Abstract in Portuguese:||Alginate fractions from Sargassum vulgare brown seaweed were characterized by 1 H NMR and fluorescence spectroscopy and by rheological measurements. The alginate extraction conditions were investigated. In order to carry out the structural and physicochemical characterization, samples extracted for 1 and 5 h at 60 C were further purified by re-precipitation with eth- anol and denoted as SVLV ( S. vulgare low viscosity) and SVHV ( S. vulgare high viscosity), respectively. The M/G ratio values for SVLV and SVHV were 1.56 and 1.27, respectively, higher than the ratio for most Sargassum spp. alginates (0.19–0.82). The homopolymeric blocks F GG and F MM of these fractions characterized by 1 H NMR spectroscopy were 0.43 and 0.55 for SVHV and 0.36 and 0.58 for SVLV samples, respectively, these values typically being within 0.28–0.77 and 0.07–0.41, respectively. There- fore, the alginate samples from S. vulgare are much richer in mannuronic block structures than those from other Sargassum species. Values of M w for alginate samples were also calculated using intrinsic viscosity data. The M w value for SVLV (1.94 · 10 5 g/mol) was lower than that for SVHV (3.3 · 10 5 g/mol). Newtonian behavior was observed for a solution concentration as high as 0.7% for SVLV, while for SVHV the solutions behaved as a Newtonian fluid up to 0.5%. The optimal conditions for obtaining the alginates from S. vulgare were 60 C and 5 h extraction. Under these conditions, a more viscous alginate in higher yield was extracted from the seaweed biomass|
|metadata.dc.type:||Artigo de Periódico|
|Appears in Collections:||DFIFA - Artigos publicados em revista científica|
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