EFFECTIVE COMPONENT IN ¦Á-AMYLASE PREPARATION FOR UNHAIRING

Abstract

The use of ¦Á-amylase preparations (AP) in sulfide and lime free unhairing systems has recently received renewed interest. However, the mechanism of AP action on hides or skins remains unclear. AP is generally a mixture of ¦Á-amylase and concomitant protease(s), and it is not yet known which components of AP are effective in unhairing. To investigate whether ¡°pure¡± ¦Á-amylase or concomitant protease(s) are mainly responsible for unhairing, a protease-free ¦Á-amylase preparation (PFAP) and an amylase-free ¦Á-amylase preparation (AFAP) were prepared by selective inactivation of protease(s) and ¦Á-amylase in AP respectively. AP, PFAP and AFAP were employed for unhairing of cattle hide for 4 h at 25 oC, and their effectiveness of unhairing was evaluated by analyzing the extent of removal of hair, epidermis and protein from hide. The results indicated that rather than ¡°pure¡± ¦Á-amylase, the concomitant protease(s) in AP were the effective components for unhairing. This suggests that the mechanism of AP action on hides should be consistent with the mechanism of enzymatic unhairing with proteases. RESUMENEl uso de preparados ¦Á-amilasa (AP) en sistemas de pelambre libres de sulfuro y cal ha recibido recientemente un renovado inter¨¦s. Sin embargo, el mecanismo de acci¨®n de AP en las pieles sigue siendo poco clara. AP es generalmente una mezcla de ¦Á-amilasa y proteasa(s) concomitantes, y todav¨ªa no se conoce cu¨¢l de los componentes de AP son eficaces en el depilado. Para investigar si la ¦Á-amilasa "pura" o proteasa(s) concomitantes son responsables principalmente del depilado, una preparaci¨®n de ¦Á-amilasa libre de proteasa (PFAP) y una preparaci¨®n libre de ¦Á-amilasa (AFAP) fueron preparados mediante la inactivaci¨®n selectiva de las proteasa(s) y ¦Á-amilasa en AP, respectivamente. AP, PFAP y AFAP fueron empleados en el depilado de cuero vacuno durante 4 horas a 25oC, y su eficacia en el depilado se evalu¨® analizando el grado de eliminaci¨®n de pelo, epidermis y prote¨ªnas de la piel. Los resultados indicaron que en lugar de la ¦Á-amilasa "pura", la proteasa(s) concomitantes en AP fueron los componentes eficaces en el depilado. Esto sugiere que el mecanismo de acci¨®n de AP en pieles debe ser consistente con el mecanismo de depilado enzim¨¢tico con proteasas.