Enhancing microalgal proteins for nutraceutical and functional food applications

• Microalgae offers sustainable, high-protein, vegan sources with diverse applications. • Microalgal proteins offer diverse amino acids, low allergenicity, and distinct bioactivities. • Research emphasizes bioactive microalgal proteins in nutraceuticals and functional foods. • Scalability and cultivation optimization remain critical challenges in production. • Innovations in protein hydrolysates, concentrates, and isolates enhance quality and functionality. Despite their immense potential, microalgae are quite potential agents for sustainable, lucrative, easily produce, and vegan protein source, either due to high protein content in a few microalgal species or the high protein productivity. Compared to traditional plant-based proteins, the popularity is growing for microalgal protein products is because of their diversity, essential amino acids, less allergenicity, nutritious composition, functional properties, sustainability, and potential for bioactive compounds. Despite these advantages, some challenges linked to the production of microalgae protein, their scalability, and optimization of mass-multiplication techniques need to be studied. The literature to date lacks a comprehensive review that addresses the nutraceutical enhancement and optimization of protein yield in microalgae. This review aims to bridge this gap by dissecting the processes involved in the formation of microalgal protein hydrolysates, concentrates, and isolates. It explores methodologies for enhancing protein content, with a particular emphasis on the resultant nutraceutical improvements, including their bioactivities, functional properties in food systems, and broader industrial applications. This synthesis offers a critical perspective on how these processes can be harnessed to advance both scientific understanding and practical applications in the field.