酸性蛋白酶软化蓝湿革的工艺条件优化

Optimization of process conditions for wet blue bating with acid protease

优化了酸性蛋白酶软化蓝湿革的工艺条件.结果 表明:胃蛋白酶和537酸性蛋白酶宜在pH值3.0~3.5、35 ℃下软化蓝湿革,软化前最好水洗蓝湿革,并将回湿与软化异浴进行.软化过程中,酸性蛋白酶在蓝湿革内的传递速率较慢,但当软化6h时,即使仅用0.2%的酸性蛋白酶也能基本渗透蓝湿革.软化6h后,蓝湿革的得革率增加,毛孔张开且清晰可见,软化废液的羟脯氨酸浓度低于20 mg/L.这说明酸性蛋白酶对蓝湿革的长时间作用,并不会造成胶原纤维的过度损伤,反而有利于打开粒面,增加得革率.

The conditions of bating wet blue with acid protease were optimized.The results show that bating wet blue with pepsin and 537 acid protease is preferably carried out at pH 3.0.3.5 and 35℃.Moreover,it is better to wash wet blue before bating,and to undertake the rewetting and bating processes in different baths.During bating,acid protease transferred slowly in wet blue,but after bating for 6 h,acid protease almost penetrated the wet blue even if using only 0.2%protease.Additionally,the wet blue has higher yield and open and clear pores after bating for 6 h,and the concentration of hydroxyproline in bating effluent is lower than 20 mg/L.This indicates that the long duration action of acid protease on wet blue would not excessively damage collagen fibers.On the contrary,this action is beneficial to opening the grain and increasing the yield of wet blue.