Microalgae Proteins for Sustainable Food Systems: A Comprehensive Review of Advanced Extraction Technologies, Functional Performance, Bioactivity, and Industrial Translation

ABSTRACT

Microalgae have emerged as one of the most technically feasible sustainable protein sources due to their high protein content, balanced amino acid profile, rapid biomass productivity, and low land and freshwater requirements. This review provides a comprehensive assessment of protein‐rich microalgae, including Limnospira ( Spirulina ), Chlorella , Microchloropsis , Tetraselmis , and other commercially relevant species. Conventional extraction methods (solvent, acid, alkaline, mechanical, and thermal) are critically compared with non‐conventional and advanced technologies such as ultrasound‐assisted extraction, microwave‐assisted extraction, enzyme‐assisted extraction, pulsed electric field, high‐pressure processing, subcritical water extraction, deep eutectic solvents, ionic liquids, membrane separation, and integrated biorefinery approaches. The influence of extraction techniques on protein yield, purity, functionality, and bioactivity is discussed in detail. Functional properties, including solubility, water‐ and oil‐holding capacity, emulsification, foaming, and gelation, are evaluated alongside emerging health‐promoting effects, such as antioxidant, anti‐inflammatory, antihypertensive, and gut‐modulating activities. The review further addresses safety, regulatory, sensory, sustainability, and techno‐economic considerations that currently limit large‐scale commercialization. Finally, future perspectives highlight the role of integrated biorefineries, low‐solvents, and artificial intelligence‐driven process optimization in accelerating the industrial adoption of microalgae proteins.