Is this the way?
Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
Sheepskin, a by-product of the meat industry, is then often processed to leather, primarily for the clothing industry. Where the tanneries are distant from the abattoirs and freezing works, the raw skins have to be transported long distances to be processed. In warm weather, there is the potential for putrefaction of the skins which then have to be disposed of at a cost. The first step of leather processing is to remove the wool from the skin (depilate) without damaging it. Conventional depilation involves the use of strong alkali and sulfide, chemicals that are harmful to the environment and also to the tannery workers due to the potential production of hydrogen sulfide, a toxic, flammable gas. To solve this problem, scientists have been looking to depilate using enzymes as these are environmentally friendly. Various enzymes, such as collagenase, keratinase, and proteases have been shown to be able to remove hair from skin, but unfortunately usually damage it. Furthermore, at present they are not cost-effective at the industrial level. We have found a simple solution, a derivative of a dairy by-product, that prevents putrefaction, preserving the skin for days at room temperature. In addition, it allows easy removal of the wool from the skin. Scanning electron microscopy showed there was no obvious damage to the depilated skin and that the wool is cleanly removed from the hair follicle. To assess any less visible damage that may have occurred as a result of soaking the skin, biochemical analyses were carried out to measure changes to the amino acid composition, crosslink and proteoglycan concentrations of the depilated skins. Culture dependent methods used to isolate the microorganisms present in the solution after depilation, showed that only four main species were consistently found in the depilation fluid and on the skins. Metagenomic analysis, confirmed these findings and is being used to follow the changes in the microbiome during the course of depilation. This presentation will describe the progress that has been made to understand the science behind these observations and compare the properties of skins depilated using this method with those depilated using the traditional beamhouse process.