ABSTRACT
Marine algae, including both macroalgae (seaweed) and microalgae, contain important polysaccharides. Seaweed, the multicellular algae rich in minerals and vitamins found in marine waters, has been an important component of food, feed, and medicine in the Orient for several centuries; however, very few of the world’s available seaweed species are used globally as food sources. In the Western world, seaweed is almost exclusively used for the extraction of important food hydrocolloids, including carrageenan, alginic acid, and agar, which are traditionally used for food product development. The major food polysaccharides are agar, alginates, and carrageenans; the minor polysaccharides include sulfated fucose (brown seaweed), xylans (certain red and green seaweed), and cellulose (which occurs in all genera but at lower levels than found in higher plants), laminarin (brown species), and Floridean starch (amylopectin such as glucan), the storage polysaccharides most notably found in red seaweed.1 At least a few species of microalgae have been recognized as functional foods because of the presence of signicant amounts of nutrients such as vitamins, proteins, and carotenoids in them. They also contain signicant amounts of polysaccharides. Nevertheless, only a few selected species are currently being used in foods.2 This chapter discusses the isolation and characterization of polysaccharides from both seaweed and microalgae.
