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 vi...