Extraction of Marine Bioactive Compounds from Seaweed: Coupling Environmental Concerns and High Yields

This review examines recent advances in the extraction of valuable compounds from seaweed biomass, focusing on practical feasibility and environmental sustainability. There is a growing importance of seaweed biomass in terms of the study and acknowledgment of its untapped biotechnological potential (multiple compounds and biological activities) and in terms of economic impact. Conventional extraction techniques largely fail to address this challenge, even if optimized. This has led to the development and testing of innovative technologies as solutions for a 'green' and effective extraction of components from seaweed biomass and to biorefinery processes. There are large differences in outcomes between alternative processes, depending on the matrix, operational parameters, and targeted compounds and activities. Despite the positive results of some techniques, such as those based on physical mechanisms, namely Microwave-Assisted Extraction (MAE) and Ultrasound-Assisted Extraction (UAE), and on enzymatic selectivity, i.e., Enzyme-Assisted Extraction (EAE), there is no universally effective technique and approach, thus justifying integrated approaches combining different techniques. The application of 'green' solvents was also assessed and proven to harbor a large potential, just as the wet route. Although technical difficulties, outcome variability, and economic viability problems are relevant, recent progress in seaweed processing paves the way for a future blue economy.