From Poultry Feather Waste to Keratin-Based Biomaterials: Advancing Circular Bioeconomy Through Sustainable By-Product Valorization

Poultry feather waste, one of the major by-products of the poultry industry, represents an underutilized protein-rich biomass with significant potential for sustainable valorization within the circular bioeconomy. This narrative review examines recent advances in the use of poultry feathers as a renewable source of keratin for the development of keratin-based biomaterials. A structured literature search of original research articles published between 2015 and 2026 resulted in a final primary evidence map of 524 records, which was used to evaluate current knowledge on poultry feather management, keratin structure and properties, extraction technologies, and the development of feather-derived biomaterials. The reviewed literature indicates that keratin recovery can convert feather waste into higher-value materials, although its environmental performance depends on the extraction route, energy and chemical requirements, and comparison with established feather-management pathways. Recent advances highlight the potential of feather-derived keratin for biodegradable films, composites, hydrogels, coatings, packaging, biomedical, agricultural, and environmental applications. However, challenges remain regarding scalable extraction technologies, material performance, process standardization, and industrial implementation. This review provides a comprehensive overview of current research and identifies future directions for integrating poultry feather valorization into circular bioeconomy strategies, supporting resource efficiency and the development of sustainable bio-based materials.