Purification and characterisation of feathers prior to keratin extraction

Keratin derived from chicken feathers is an inconvenient waste product of the poultry-farming industry, and therefore it is presently the subject of much investigation. Feathers contain some fatty and waxy substances, other than keratin that exists in an α-helix conformation in feather barbs and barbules, and as ß-sheet in calamus and rachis. Although investigations have been conducted exploring potential use of keratin derived from chicken feathers, the initial purification phase is important for isolating the keratin from other materials. An original chicken feather contains many biological organisms together with other extraneous material from the time it was plucked from a chicken. Unprocessed chicken feathers are potentially biologically hazardous, caused by the presence of blood borne pathogens, thus it is important that they are decontaminated upon receipt. The aim of this study is conduct a comparative analysis of different purification techniques to decontaminate chicken feathers prior to keratin isolation. These processes include surfactant washing using an ionic and a non-ionic surfactant, soxhlet extraction with ethanol, ozone and sodium chlorite solution bleaching. Fourier transform infrared spectroscopy, optical microscopy, pH and scanning electron microscopy were used to characterise the feathers and residues after purification and extraction. FTIR analysis confirmed that there are no significant changes in the chemical structure of fibers after each wash treatment. However the residue from ethanol extraction was characteristic of a long hydrocarbon chain ester, typical of a fat