Kappaphycus alvarezii macroalgae: An unexplored and valuable biomass for green biorefinery conversion

Background: Kappaphycus alvarezii is the 5th world's most cultivated macroalgae, since it is an essential source of carrageenan, widely used in food industry. However, K. alvarezii is an unexplored biomass for green biorefinery conversion, since its composition includes valuable proteins, lipids, phenolic compounds, among others. Although there are reviews on K. Alvarezii cultivation and pharmacological properties, no information is available regarding extraction techniques applied to this algae biomass. Therefore, this review covers the lack of information on biorefinery concept applied to K. alvarezii and suggest sequential extractions to recover carrageenan and high-added value molecules by using non-conventional methods. Scope and approach: This critical review presents the most recent data on K. alvarezii, including its scientific trends, production and potential. It also deals with non-traditional methods for sequential extractions applied to K. alvarezii. The search for available data was extended to the group of red algae to consider the concept of biorefinery. Key findings and conclusions: K. alvarezii biomass can be used to obtain chlorophyll, p-carotene, essential amino acids (aspartic acid, glutamic acid and phenylalanine) and phytohormones (indole acetic acid, zeatin, kinetin and gibberellic acid). Therefore, we provide several sustainable insights to sequentially recovery carrageenan and other bioactive compounds from K. alvarezii.