Fucoidans exhibit various biological activities, including
immunomodulation, anti-cancer, and pathogenic inhibition. This approach can be used
to isolate numerous natural resources and various applications in the pharmaceutical,
food, and cosmetic industries. Fucoidan surrounds sulfated L-fucose as a vital
monosaccharide and small amounts of mannose, galactose, glucose, xylose, arabinose,
uronic acid, and glucuronic acid. Structural analysis revealed that purified fucoidan
consists of a carbohydrate chain composed mainly of (1→3)-linked or (1→4)-linked Lfucose residues, with sulfate groups at C-2 and C-4 positions. Fucose residues at C-3 or
C-4 serve as branch sites for galactose residues with 1–4)-linkages. Low molecular
weight fucoidan, medium molecular weight fucoidan, and high molecular weight
fucoidan are the three different types of fucoidan based on molecular weights. The
structure of fucoidan determines its bioactivity and its economic and commercial value
depending on the species, geographical location, and harvest season. Therefore,
shortened phases, low temperatures, and low acidity are used in the extraction
technique to determine the distinct structures of fucoidans. In industrial manufacturing,
the extraction techniques must be environmentally friendly and cost-effective. In this
chapter, classical extraction and purification procedures such as hot water, acidic or
alkaline extractions, and chromatographic techniques are discussed and detailed.
Microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and
enzyme-assisted extraction (EAE) are innovative techniques for fucoidan extraction.
Optimization strategies for pH, temperature, pretreatment conditions, extraction time,
and yield parameters also discussed in detail.
Keywords: Acidic and alkaline extraction, Anion exchange chromatography, Bioactivities, Classical extraction methods, Enzyme-Assisted Extractions, Extraction, Fucoidan, Hot water extraction, Isolation techniques.
