The Quest for Phenolic Compounds from Seaweed: Nutrition, Biological Activities and Applications

Seaweeds are macroscopic marine algae that are allocated into three categories based on the seaweed color (green, brown and red seaweeds). Seaweeds are known for its nutrition and beneficial non-nutritive compounds. Seaweeds have ample nutrition content including carbohydrates, minerals, proteins, and vitamins. Green seaweeds have a high concentration of carbohydrates and lipids whereas red seaweeds have abundant content of proteins. The mineral content ranges up to 36% of its dry weight. The beneficial non-nutritive compounds are phenolic compounds that are classified into phenolic acids, flavonoids, bromophenols and phlorotannins in seaweeds. The phlorotannin compounds are found mostly in brown seaweeds whereas the bromophenols are observed in red seaweeds. The phenolic compounds identified demonstrated bioactive properties which have been confirmed through in vivo cell culture studies. Due to seaweed's beneficial properties, the seaweed biomass have been consumed as a portion of convenience food in the Asian diet and has expanded to the Western diet. Over the last few decades, the extract or the biomass has been used in making fertilizers, animal feed, pharmaceuticals, and cosmeceuticals. This review helps to understand the nutrition content, especially phenolic compounds with their bioactive properties and recent development in applications.