Extraction of proteins and other functional components from red seaweed (Rhodophyta)

Red seaweeds are a major industrial source of agar and carrageenan. They also contain high amounts of other polysaccharides and higher amounts of proteins than brown seaweeds. Some species of red seaweed also contain polyphenols with antioxidant activities as well as being a source of carotenoids and phycobiliproteins. However, there are currently no commercial-scale methods for extracting those bioactive compounds. This chapter provides an overview of various methods for extracting all these functional compounds from red seaweeds. Whereas the main emphasis is on the extractions of proteins, extractions of polysaccharides (carrageenan and agar) and antioxidants (phenolic compounds) are covered. Multi-extraction approaches for extractions of bioactive compounds from red seaweeds are also described.