Flesh removal on fresh skins for leather prodn. - comprises applying proteolytic enzyme with strong elastolcytic activity at pH 5-10 and 5-30 deg. C prior to lifting

摘要

Removal of flesh on skins and hides by removal of the hypodermal connective tissue (HCT) comprises subjecting fresh skins at 5-30 deg. C pH 5-10 to one or more proteolytic enzymes (E.C.3.4, Kirk-Othmer, Encyclopedia of Chemical technology, 3rd edition, vol. 9, 199-202, Wiley, 1980) with large elastolytic activity for 2 to 24 hours and possible mechanically removing the HCT. Pref. the method is performed in the presence of a wetting agent. Pref. alkaline proteases (E.C.3.4.21) are used in 1000 to 30000 Lohlein-Volhard-units (LVU) per kg. skin (claimed). The alkaline proteases used have a mol.wt. of 25000-35000. The proteases are (a) bacterioproteases from Bacillus (B.), e.g. B. subtilis, B. licheniformis and B. firmus, (b) subtilisins (claimed) and (c) serine proteases, e.g. from Aspergillus (A.) oryzae, A. flavus and A. soyae. USE/ADVANTAGE - Removal of flesh on fresh skins improves the leather liming. With the current method the removal on fresh skin is almost complete prior to liming with no need for a further step.