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Title: Characterizing wool keratin

item Cardamone, Jeanette
item Nunez, Alberto
item Garcia, Rafael
item Ramos, Mila

Submitted to: Electronic Publication
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2009
Publication Date: 6/1/2009
Citation: Cardamone, J.M., Nunez, A., Garcia, R.A., Ramos, M. 2009. Characterizing wool keratin. Research Letters in Materials Science. 2009(5). Available:

Interpretive Summary: Traditional uses for wool are in fiber and textile applications. Yet wool is a pure source of keratin protein that is receiving current interest in the development of new products for the medical, biomechanical, pharmaceutical, hair, skin, and cosmetic industries. As such, we undertook this study to further characterize the properties of solubilized wool keratin. Keratin was extracted from wool by exposing wool to highly alkaline solutions designed to break down its fundamental chemical structure to form soluble keratin in the form of water-soluble powder. Keratin powders obtained from several solubilizing systems were characterized by microscopy to show their microcrystalline structures which were composed of the fragments of the inner and outer cutex of the wool fiber. The fragments of intact protein were identified for their component amino acids and their chemically reactive groups. Solubilized wool fibers having the transformed morphologies of keratin powders exhibit the unique characteristics of natural keratin and upon characterization can be the starting materials for developing novel products and applications.

Technical Abstract: Keratin from wool is a reactive, biocompatible, and biodegradable material. Efficient alkaline extractions gave yields of 68% to 82% protein within 2 to 5 hours of exposure at 65 ºC. The water soluble keratin preparations contained intermediate filament and microfibrillar component-proteins of fractured, residual cuticle and cortical cells. Morphologies and functions were documented by SEM, amino acid analysis, SDS-PAGE gel electrophoresis, MALDI-TOF/TOF, and FTIR. Oxidation by peroxycarboximidic acid oxidation produced a variety of keratin products with distinct microcrystalline structures. Keratin from wool can provide novel products with wool as a model for lower value sources such as cattle hair.