Purification of avian biological material to refined keratin fibres

Abstract

Keratin derived from chicken feather fibres (CFFs) has many potential applications that are constrained by the quality and pathogen content after purification treatment. The pathogen activity after purification has not been evaluated elsewhere. Plucked chicken feathers are prone to impose biological hazards due to accommodating blood-borne pathogens; therefore, establishing an efficient purification process is crucial. Bactericidal performance of surfactants (anionic, non-ionic, and cationic), bleach (ozone and chlorine dioxide), ethanol extraction, and a combination method comprising surfactant-bleach-ethanol extraction on chicken feathers was investigated via (A) standard plate count and enumeration of Escherichia coli, Pseudomonas species, coagulase positive Staphylococcus, aerobic and anaerobic spore-formers and (B) Salmonella and Campylobacter detection tests. Among the purification methods, only ethanol extraction and combination methods eliminated Salmonella from the untreated feathers. Although ethanol extraction exhibited superior bactericidal impact compared to the combination method, the feathers treated through the latter method demonstrated superior morphological and mechanical properties. Scanning electron microscopy-energy dispersive spectroscopy was employed to determine the remaining content of selected purifiers on treated CFFs. Fourier-transform infrared spectroscopy confirmed the successful removal of fatty esters from CFFs using nominated purifiers. Ethanol extraction was found to be the most efficacious single treatment, while combination of surfactant and oxidative sterilizer with ethanol was superior.