Chicken feather dissolution to obtain keratin

The dissolution of chicken feathers was investigated for the purpose of reducing solid waste and obtaining keratin. For the first part, the effects of sodium sulfite (0.05–0.3 M), urea (0–4 M), temperature (50–85 °C), and incubation time (2–4 h) on feather dissolution were investigated via a factorial design. Another factorial design was applied to investigate the effects of sodium dodecyl sulfate (SDS) (0–0.02 M), and lower ranges of urea (0.5–2 M), and incubation time (0.5–2 h) on feather dissolution. Keratin was precipitated from the solutions by ammonium sulfate and characterized via FTIR and SDS‒PAGE methods. The results of the first part demonstrated the feasibility of feather dissolution in the presence of sodium sulfite, and the effectiveness of urea and temperature on feather dissolution. For this part, a maximum feather dissolution of 45.35% was obtained with sodium sulfite and urea concentrations of 0.05 M and 4 M, respectively, at 85 °C for 4 hours. The results of the second part revealed a positive effect of SDS on feather dissolution. A maximum feather dissolution of 57.63% was obtained with sodium sulfite, urea, and SDS concentrations of 0.05 M, 2 M, and 0.02 M, respectively, at 85 °C for 2 hours. FTIR analysis confirmed the keratinous nature of the precipitated protein, and SDS‒PAGE revealed that the mass of the protein molecules was less than 15 kDa. This work confirms the feasibility of chemical dissolution of chicken feathers to obtain keratin as a useful product.