Leather bioprocess intensification: Ultrasound assisted novel enzymatic hair-loosening system for leather processing

The use of enzymes for hair loosening in leather processing provides a cleaner option. However, there is need to improve the efficiency of these unit operations involving bioprocess by way of process intensification techniques, such as, the use of ultrasound. In this paper, the use of ultrasound has been studied in native enzyme papain (A) based hair-loosening system and compared with commercially available enzyme Microdep-C (B), combination of enzyme system (A+B) and conventional Na2S system. Various process parameters, such as, enzyme concentration, time and ultrasound power on the hair-loosening efficacy, were studied. Enzyme concentration (5-6%) and ultrasound (100 W) were found to give better hair loosening under given process conditions. The results indicated that papain based unhairing system was better and the use of ultrasound provided better hair-loosening efficacy. The reason for the ultrasound driven enhancement could be due to better diffusion of enzymes through skin matrix to reach the hair-bulb cite for interaction and dispersion of unhairing formulation employed. Thus, the present process provides novel, eco-friendly, enzymatic unhairing system in leather processing based on native enzyme or a combination of enzyme system.