Development of an eco-friendly Enzymatic Dehairing of skins and hides using Alkaline Protease and Keratinase

This thesis presents the development of an enzyme assisted and enzyme mediated methods as an alternative and eco-friendly approach to minimize the use of chemicals that will reduced the environmental impact in manufacturing of leathers. In this research, two types of protease namely alkaline protease and keratinase were used in the enzymatic application in dehairing. Four sets of experiments of cow hides were performed. The sets included the use of chemicals which are 5% calcium oxide (CaO) and 2% sodium sulfide (Na2S), the use of 2.5% enzymes with 5% CaO, the use of two types of enzymes and the use of enzymes only. The hides which undergo treatment with enzymes eliminated 85% of hair after 26 hours under shaking condition at 37°C while the treatment with enzyme together with 5% calcium oxide eliminated 100% of hair under the same conditions. The treatment of sodium sulfide along with calcium oxide also eliminated 100% of hair faster than other two treatments. As revealed by Scanning Electron Microscopy, the surface of the hides that were treated with enzymes was smoother and silkier than hides that were treated by chemicals. Hence, these results revealed that the enzymes assisted method can be implemented in commercial leather manufacturing in order to reduce the use of severe sodium sulfide. The application of enzyme assisted technique can help in the minimization of pollutions in the environment and can be good alternatives for the production of good quality of leather.