There is a growing demand to find an effective extraction process of sulfated polysaccharides from brown
algae to conserve its structure and biological activity. Fucoidan was recovered from Sargassum sp. using a
hot buffer extraction process. BoxeBenhken experimental design was evaluated to study different
conditions of temperature, pH and buffer: alga ratio on fucoidan yield and its sulfate content. By solving
the regression equations and analyzing 3-D plots, the optimum conditions were at extraction temperature
60
C, pH 4.0, and ratio of buffer: alga 10.0 mL/g. Under these conditions, the experimental fucoidan
yield, and sulfate content were 19 and 47.6% (w/w), respectively, which were in good agreement with the
predicted values. The use of hot buffer extraction was efficient to obtain a high fucoidan yield with
maintaining high sulfate contents. Fucoidan preparations showed variations in antioxidant properties
using various antioxidant assays. Increasing reducing antioxidant activity and hydroxyl radical scavenging
of fucoidan extracts was attributed to increasing total sugars, fucose, and uronic acids. The data
obtained suggested that the sulfate groups might act as reductones rather than radical scavengers to
contribute to the antioxidant activity of fucoidan. Additionally, proteinaceous and phenolic compounds
co-extracted with crude fucoidan contributed to its antioxidant potential. Crude fucoidan demonstrated
good emulsion stabilizing capacities, especially with cedar wood oil and xylene. These results suggest the
use of the crude fucoidan as a good alternative to many synthetic polymers, as well as other natural
polysaccharides, in several applications in the food, pharmaceutical, cosmetic, textile, paper and petroleum
industries.