Feasibility of posthydrolysis processing of hydrothermal extracts from Sargassum muticum

The posthydrolysis of the crude fucoidan extracted during hydrothermal treatment of Sargassum muticum was carried out with mineral acid or without added acid and aided by microwave or by ultrasound processing during short periods. The liquors produced under non-isothermal treatments at 150 and 170 °C were subjected to alginate precipitation and the soluble crude fucoidan to posthydrolysis. Acid posthydrolysis caused a steady increase in the monosaccharide content. Ultrasound (US) was the intensified process selected for assisting short term posthydrolysis, which caused depolymerization of crude fucoidan, but did not significantly change the saccharide or sulfate content. The antiradical and cytotoxic properties against lung and colon cancer cells were significantly enhanced by US assisted posthydrolysis.