碱酶结合脱毛法在牦牛皮上的应用(Ⅰ)

A Paint Unhairing of Lower Sulfide Associated with Enzyme for Yak Hide(Ⅰ)

采用碱酶（一种碱性蛋白酶、碱性脂肪酶和糖化酶的复合酶）结合脱毛法,目的是降低牦牛皮脱毛工序中硫化钠的用量.在实验中,首先分析硫化钠的浓度和酶的用量对牦牛皮脱毛的影响,然后通过碱酶结合脱毛的实验 得到了牦牛皮脱毛液的最适配方：以皮重为基准,按照通常的涂灰量0.2g/g皮,温度20℃,脊背部位为硫化钠的质量浓度30～35 g/L,酶的用量0.3%;边腹部位为硫化钠的浓度15～20 g/L,酶的用量0.2%.此方法脱毛时间为12～14 h,脱毛干净,粒面层完好,无残留毛根.与传统的脱毛液中硫化钠的质量浓度（脊背部位60～65g/L,边腹部位为30～35 g/L）相比,此方法可使硫化钠的质量浓度降低约50%,大大降低了硫化物的污染程度.

A Lower concentration of sodium sulfide associated with the complex enzyme was studied for reducing the amount of sulfide in the paint unhairing of yak hide. The effects of unhairing with different concentrations of sodium sulfide and various amount of the enzyme were firstly evaluated. Then, the optimum prescription was obtained by the experiment of combination sodium sulfide and enzyme. As usual amount of 20% based on the weight of hide, the different area on the hide was painted with different paste. The better concentration of sodium sulfide is 30-35 g/L for back area and 15-20 g/L for belly. Also, the appropriate amount of the complex enzyme based on the weight of hide is 0.3% for back and 0.2% for belly. After the paste was painted on the hide for 12 hours, all of the hairs could be cleaned up and there are not any residual hair roots in the grain Layer. Compared with the traditional unhairing process, this method could make 50% of the sodium sulfide off, so the impact of sulfide on environment may effectively decrease.