Functional hydrocolloids from seaweeds

The global production of seaweeds continues to grow for production of food hydrocolloids, i.e. carbohydrate polymers that form viscous suspensions and gels in water. Because of their unique gelling properties seaweed hydrocolloids are used in various food and pharmaceutical applications. Asian countries and Tanzania are currently the main producers of seaweed hydrocolloids based on cultivation of seaweeds such as Kappaphycus alvarezii, Gracilaria spp. and Laminaria spp. that hold carrageenan, agar, and alginate, respectively. In this review we summarize the chemistry, food uses, and gelling mechanisms of carrageenan, agar, and alginate, and describe the key techniques and principles for their extraction from seaweeds. We also discuss the options for local seaweed manufacturing as a business opportunity in countries along the West African coast.