Extraction of keratin from unhairing of bovine hide

Abstract

Hair waste from unhairing of bovine hide has high protein content and is also a current issue in tanneries as it causes high organic load to the wastewater. Given that, this study aims to recover keratin from bovine hair by investigating its hydrolysis from remaining solid hair from leather processing and unprocessed hair. For the keratin hydrolysis, 2-mercaptoethanol, Na₂S, H₂O₂, NaOCl, NaOH, C₂H₄O₂S, and HCOOH were tested. SDS-PAGE and the yield analysis of the extracted solution indicated that it was possible to recover proteins with molecular weights around 20 kDa, reusing this hair waste. In an oxidizing pathway (H₂O₂), 75% of the protein was extracted from the recovered hair powder, and a yield of up to 40% was achieved with Na₂S in a reductive pathway. Overall, the results demonstrated good recovery of keratin from bovine hair, turning what was previously considered waste into an interesting source of this protein.

Keywords:

• Bovine hair
• hair-saving process
• keratin recovery
• leather waste
• protein hydrolysis

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors would like to thank to the scholarships provided by the National Council for Scientific and Technological Development (CNPq) and Science without Borders Program.