Bating pelt with protease is an important process, which removes unwanted non-collagenous proteins from the pelt and moderately disperse hide collagen network. However, the grain surface, may be excessively hydrolyzed during bating due to the longer retention time of protease in the grain than in the middle layer caused by the low mass transfer rate of protease in pelt. Here, the effects of protease dosage, common auxiliaries and molecular weight of protease on protease transfer during bating were investigated so that we can find the key points to avoid excessive collagen damage, particularly in the grain. Observably, increasing protease dosage led to faster protease transfer and softer leather, but along with more considerable grain damage. Using penetrating agent JFC (fatty alcohol-polyoxyethylene ether) and ammonium sulfate enhanced protease transfer and simultaneously alleviated collagen damage due to the decrease in interfacial tension and electrostatic attraction between protease and pelt, respectively. Additionally, proteases with lower molecular weight transferred faster in pelt, which suggests that a potential strategy to solve the conflict between the mass transfer and the reaction of protease in pelt might be to produce/employ smaller bating proteases.

中文翻译：

---

酶促软化过程中影响毛皮中蛋白酶传质的因素

用蛋白酶软化毛皮是一个重要的过程，该过程可从毛皮中去除不需要的非胶原蛋白，并适当分散兽皮胶原蛋白网络。但是，由于蛋白酶在毛皮中的传质速率低，导致谷物中蛋白酶的保留时间比中间层更长，因此在焙烧过程中谷物表面可能会过度水解。在这里，研究了蛋白酶用量，普通助剂和蛋白酶分子量对软化过程中蛋白酶转移的影响，以便我们找到避免胶原过度破坏的关键点，特别是在谷物中。可以看出，增加蛋白酶的用量会导致更快的蛋白酶转移和更柔软的皮革，但会带来更大的谷物损伤。使用渗透剂JFC（脂肪醇-聚氧乙烯醚）和硫酸铵可增强蛋白酶的转移，同时减轻由于蛋白酶和兽皮之间的界面张力和静电吸引的降低而引起的胶原蛋白损伤。另外，具有较低分子量的蛋白酶在毛皮中的转移速度更快，这表明解决在毛皮中传质与蛋白酶反应之间冲突的潜在策略可能是生产/使用较小的软化蛋白酶。