Purification methods for chicken feather keratin

Chicken feathers are an abundant, inconvenient and troublesome waste product from the poultry industry that can be utilised as a source of keratin. The keratin exists in α-helix conformation in feather wool, and as pleated sheet in barbs and rachis. In addition to keratin, feathers contain other fatty and waxy substances. Whilst 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 dirt from when they were plucked from chickens. Unprocessed chicken feathers are potentially biologically hazardous, due to the presence of blood borne pathogens, so it is imperative that they are decontaminated upon receipt. The aim of this work is conduct a comparative study of different purification methods to decontaminate chicken feathers prior to keratin isolation. These methods were: washing the original chicken feathers using an anionic surfactant, sodium lauryl sulphate and a non-ionic surfactant, a poly(ethylene glycol). Soxhlett extraction with ethanol was performed, together with bleaching using ozone and sodium chlorite solutions. Visual observation, infrared spectroscopy, optical microscopy and scanning electron microscopy were used to characterise the feathers and residues after extraction.