Green Hybrid Extraction of Keratin for Sustainable Bio-Based Applications

Keratin is a fibrous structural protein abundantly available in human hair, wool, and feathers—materials often treated as waste. Conventional keratin extraction processes rely on harsh chemicals such as sodium sulfide, urea, and mercaptoethanol, which cause environmental pollution, health hazards, and high operating costs. This study presents a Green Hybrid Extraction Method (GHEM) that combines biological, mild chemical, and physical treatments to efficiently extract keratin from human hair waste. The process uses enzyme-assisted pre-treatment, mild reducing agents, and ultrasonic agitation to achieve high recovery with minimal chemical waste generation. Compared to conventional methods, GHEM offers a cost-effective, zero-waste, and eco-friendly solution. The extracted keratin demonstrates strong potential for cosmetic, pharmaceutical, leather, and agricultural applications, supporting circular economy and sustainable biomanufacturing. This work establishes a foundation for scalable green keratin extraction and opens opportunities for industrial adoption in developing bio-based materials from renewable waste sources.