A comprehensive review of shellfish peptides: Extraction, characterization, biological activity, and commercial potential

Shellfish peptides, recognized as a valuable source of marine bioactive compounds, have garnered increasing attention because of their diverse physiological functions and potential functional food, pharmaceutical, and cosmetics applications. This comprehensive review systematically summarizes recent advances in the extraction, purification, and structural characterization of peptides from various shellfish species, including oysters, mussels, clams, and scallops. Key biological activities, such as antioxidant, antimicrobial, antiviral, immunomodulatory, antihypertensive, antithrombotic, anticancer, osteogenic, and skin protective effects, are critically examined, with an emphasis on their underlying mechanisms and structure–activity relationships. Furthermore, this article explores the potential industrial applications of shellfish peptides while addressing major challenges with their commercialization, including large-scale production costs, issues with stability and bioavailability, and safety considerations. Finally, future research directions are proposed, focusing on high-throughput screening, nanodelivery systems, multiomics integration, gut microbiota interactions, and sustainable extraction processes. By bridging the gap between fundamental research and practical application, this review aims to promote the utilization of shellfish peptides as high-value ingredients in health-promoting products and contribute to the sustainable exploitation of marine bioresources.