Seaweeds contain large amounts of polysaccharides, notably cell wall structural polysaccharides
that are extraded by the hydrocolloid industry: alginate from brown seaweeds, carrageenans and agar
from red seaweeds. Other minor polysaccharides are found in the cell wall : fucoidans (from brown
seaweeds), xylans (from certain red and green seaweeds), ulvans in green seaweeds.