Fucoidan (Undaria pinnatifida)

Fucoidan from Undaria pinnatifida is a sulfated polysaccharide, not a whole food, so traditional macronutrient profiling differs from conventional ingredients. Key compositional data: Fucoidan content in Undaria pinnatifida (wakame) dry weight ranges from 0.5% to 4% by mass depending on harvest season, geography, and plant part (sporophylls yield higher concentrations, up to 10%). Structurally, fucoidan is composed primarily of L-fucose units (approximately 30–44% of molecular composition) with sulfate ester groups (15–20% sulfate content by weight), giving it a strongly anionic character. Minor sugar constituents include galactose, mannose, xylose, and uronic acids at concentrations of 1–10% each. Molecular weight varies broadly from 20 kDa to over 1,000 kDa depending on extraction method, which directly impacts bioavailability and bioactivity. Low-molecular-weight fucoidan (<30 kDa) demonstrates superior intestinal absorption compared to high-molecular-weight fractions, which are largely fermented by gut microbiota or excreted. In whole Undaria pinnatifida seaweed context: protein content is approximately 11–24% of dry weight; dietary fiber 32–50% of dry weight (including alginic acid, fucoidan, laminarin); iodine is notably high at 1,500–8,000 mcg/100g dry weight; calcium approximately 700–1,000 mg/100g dry weight; magnesium approximately 700 mg/100g dry weight; iron approximately 2–3 mg/100g dry weight; vitamins include vitamin K1 at approximately 5–66 mcg/100g, folate at approximately 196 mcg/100g, and riboflavin (B2) at approximately 0.23 mg/100g. Bioactive co-compounds in the same plant include fucoxanthin (a xanthophyll carotenoid, 0.2–1% of dry weight), phlorotannins, and omega-3 fatty acids (EPA trace to 0.5% of dry weight). Bioavailability note: Oral bioavailability of intact fucoidan is estimated at less than 10% for high-molecular-weight forms; enzymatic pre-hydrolysis or nanoparticle encapsulation can increase systemic absorption. Sulfation degree positively correlates with anti-inflammatory and anticoagulant potency but also with bleeding risk at high doses.