Acetone Precipitation of Heterofucoidans from Sargassum muticum Autohydrolysis Extracts.

The brown seaweed Sargassum muticum was processed by non isothermal autohydrolysis under conditions selected to maximize fucoidan solubilization (170 °C). Acetone precipitation was tried for recovery of fucose-containing oligosaccharides present in hydrolyzates. The acetone:hydrolyzate volume ratio influenced both yields and composition of the precipitated fractions. The sugar components were mostly found as oligomers, their content increased with acetone:hydrolyzate volume ratio 2.0 (v/v) exhibited slight. The fractions precipitated with 0.1 and 0.9 acetone volumes showed higher phenolic and sulfate content, which was positively correlated with the antiradical activity, and exhibited slightly cytotoxic activity against human colon adenocarcinoma cells. The highest volumes of acetone used led to a slight increase in the apparent viscosity as well as the elastic and viscous moduli of formulated aqueous dispersions of alginate. Steady-state and oscillatory shear measurements of above representative dispersions indicated that the alginate extracted after acetone precipitation exhibited a slight enhancement of the viscoelastic features. [ABSTRACT FROM AUTHOR]