Metabolites from Macroalgae and Its Applications in the Cosmetic Industry: A Circular Economy Approach

Marine macroalgae are a suitable source of ingredients due to their huge diversity, availability and nutritional and chemical composition. Their high content in proteins, carbohydrates and vitamins, but also in secondary metabolites such as phenolic compounds, terpenoids or pigments, make them great candidates for industrial applications. The cosmetic industry is one of the biggest in the world and the search for new ingredients is constantly growing as the consumer trend now is going back to those traditional cosmetics with a more natural composition. Moreover, the concept of a circular economy is also gaining importance due to the unsustainable situation of the natural resources. Although macroalgae are already used in cosmetics, especially as thickening and gelling agents, they possess an unexplored potential, not only as excipients and additives but also as a source of new active ingredients. In this context, macroalgae are considered in many cases as resources still underexploited and they could even be obtained from the waste of other industrial sectors and be used for recovering active molecules. Therefore, the aim of this review is to compile information about the different macroalgae metabolites and their possible applications in the cosmetic industry, which could employ circular economy models.