Extraction of keratin from waste chicken feathers using sodium sulfide and l- cysteine

摘要

Keratin was extracted from different segments of disposable waste chicken feathers (CF) including the whole feathers, calamus/rachis (beta-sheet) and barbs/barbules (alpha-helix), using sodium sulfide and L-cysteine. The yield of extracted keratin from sodium sulfide and L-cysteine was (similar to)88% and (similar to)66% respectively. The mass ratio of feathers to reducing agent was 1:20 and the reaction temperature was 40 degrees C for 6 h. Concentration of keratin extracted by each method was measured using the Bradford assay. The protein extracted from each feather section was characterised using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, vibrational spectroscopy including FTIR and Raman, nuclear magnetic resonance, and thermogravimetry. These results confirmed the keratin structures after each extraction methods. The study showed that alpha-helix and beta-sheet based keratin could be extracted from CF using sodium sulfide and L-cysteine with high yields. This is the first report of CF keratin extraction using L-cysteine.