Comparison of Methods for Extraction of Keratin from Waste Wool

The U.S. sheep industry, more than 80,000 producers of 40 million pounds of raw wool per year, is an important component of the meat industry. New methods for the treatment of domestic wool with keratin isolated from the unmarketable fraction of wool, and functionalized for water, oil, or insect repellency are needed. As a first step in the process, we are evaluating the effectiveness of keratin solubilization via relatively benign methods that use thioglycolic acid, bisulfite or sulfide to reduce disulfide bonds, peracetic acid or percarbonate to oxidize disulfides, and urea/thiourea as hydrogen bond disrupters. The procedures are compared in terms of quality of soluble protein, cost effectiveness, potential for upscaling, environmental and operator safety. Successful completion of this project will provide the basis for commercial development of such methods, followed by functional modification of the soluble keratin, and its application to textiles.