Structural Characterization and Rheological and Antioxidant Properties of Novel Polysaccharide from Calcareous Red Seaweed.

A novel sulfated xylogalactan (JASX) was extracted and purified from the rhodophyceae Jania adhaerens . JASX was characterized by chromatography (GC/MS-EI and SEC/MALLS) and spectroscopy (ATR-FTIR and 1 H/ 13 C NMR) techniques. Results showed that JASX was constituted by repeating units of (→3)-β-d-Gal p -(1,4)-3,6-α-l-AnGal p -(1→) n and (→3)-β-d-Gal p -(1,4)-α-l-Gal p -(1→) n substituted on O -2 and O -3 of the α-(1,4)-l-Gal p units by methoxy and/or sulfate groups but also on O -6 of the β-(1,3)-d-Gal p mainly by β-xylosyl side chains and less by methoxy and/or sulfate groups. The M w , M n , Đ, [ η ] and C* of JASX were respectively 600 and 160 kDa, 3.7, 102 mL.g -1 and 7.0 g.L -1 . JASX exhibited pseudoplastic behavior influenced by temperature and monovalent salts and highly correlated to the power-law model and the Arrhenius relationship. JASX presented thixotropic characteristics, a gel-like viscoelastic behavior and a great viscoelasticity character. JASX showed important antioxidant activities, outlining its potential as a natural additive to produce functional foods.