Process Optimization of Keratin Extraction from Chicken Feathers Using Alkaline Oxidation: A Taguchi L9 Orthogonal Array Study

The valorization of poultry feather waste as a sustainable source of keratin aligns with circular economy principles and offers an environmentally responsible solution to managing agro-industrial residues. In this study, an eco-friendly alkaline oxidative extraction method using hydrogen peroxide (H₂O₂) was investigated for recovering keratin from chicken feathers. The process was optimized through a Taguchi experimental design to enhance both extraction efficiency and protein regeneration. Four critical parameters: H₂O₂ concentration, pH, temperature, and extraction time, were studied at three levels each using an L9 orthogonal array. Their effects on solubilization and regeneration yields were systematically evaluated. Statistical analysis revealed that pH and H₂O₂ concentration had the most significant influence on keratin yield. The optimal conditions for maximum solubilization (2 M H₂O₂, pH 12, 75 °C, 1.5 h) yielded high extraction efficiency, whereas a lower H₂O₂ concentration (1 M) favored better regeneration, indicating that excessive oxidation may compromise protein reassembly. Regression models and ANOVA confirmed the statistical significance of these findings, with R² values of 94.25% for solubilization and 78.23% for regeneration. The extracted keratin maintained essential structural features, as verified through subsequent characterization. This work not only improves the sustainability and effectiveness of keratin recovery but also establishes a statistically robust optimization approach. The methodology and insights provided can support future efforts in developing high-quality keratin-based biomaterials for biomedical, cosmetic, or environmental applications.