酶解法对缫丝废水分离蛋白表面性能的影响

Effect of Enzymatic Hydrolysis on the Surface Properties of Protein Separation in Silk Reeling Wastewater

针对汰头废水分离蛋白质表面活性很差的特点,为提高分离蛋白表面活性,采用Alcalase碱性蛋白酶通过pH-stat法对控制分离蛋白的水解程度进行了研究,探讨水解程度对其结构和性能的影响。结果表明:随着水解度的变化,分离蛋白结构和性能变化显著。实验测得未经酶解的汰头废水分离蛋白荧光吸收峰为364 nm,粒径为5.17 nm,Zeta电位绝对值为21 mV,可溶性蛋白含量为1.36 mg·mL^-1,起泡性仅为5%且稳定性很差,乳化性和乳化稳定性分别为13.48%和79.48%,游离氨基含量为0.15 mmol·L^-1。经Alcalase碱性蛋白酶处理后的分离蛋白,当水解度为3.85%时荧光吸收峰位置红移至366 nm,当水解度为1.79%时粒径最小,为3.19 nm,水解度在2.68%时Zeta电位绝对值增大至32.9 mV,当水解度为3.85%时可溶性蛋白含量最高达到2.15 mg·mL^-1;当水解度为3.85%起泡性能最好达到50.83%,泡沫稳定性则在水解度为5.37%达到最好值为68.5%;乳化性在水解度为3.85%时达到最大值118.70%,乳化稳定性则在水解度达到4.35%时达到最大值453.40%;当水解度在4.35%游离氨基含量最大为4.5 mmol·L^-1。研究结果为开发汰头废水利用提供了理论依据,为后续开发新型蛋白质基表面活性剂有研究提供参考价值。

Aiming at the characteristics of poor surface activity of protein separated from the reeling wastewater, in order to improve the surface activity of isolated protein, Alcalase alkaline protease was used to study the degree of hydrolysis of the separated protein by pH-stat method, and the effect of the degree of hydrolysis on its structure and performance was discussed. The results show that with the change of the degree of hydrolysis, the surface properties of the isolated protein change significantly. The experimental results showed that the fluorescence absorption peak of the separated protein from reeling wastewater without enzymatic hydrolysis was 364 nm, the particle size was 5.17 nm, the absolute value of the Zeta potential was 21 mV, the soluble protein content was 1.36 mg·mL-1, the foamability was only 5% and the stability is very poor, the emulsification and emulsification stability are 13.48% and 79.48%, respectively, the free amino content is 0.15 mmol·L-1. When the protein was treated with Alcalase alkaline protease, the fluorescence absorption peak position was red-shifted to 366 nm when the degree of hydrolysis was 3.85%, the minimum particle size was 3.19 nm when the degree of hydrolysis was 1.79%, and the absolute value of Zeta potential was 2.68%. When the degree of hydrolysis is 3.85%, the soluble protein content reaches a maximum of 2.15 mg·mL-1;When the degree of hydrolysis is 3.85%, the foaming performance is best to reach 50.83%, and the foam stability is at the degree of hydrolysis of 5.37%, the best value is 68.5%;emulsification reaches a maximum of 118.70% when the degree of hydrolysis reaches 3.85%;emulsification stability reaches a maximum of 453.40% when the degree of hydrolysis reaches 4.35%;when the degree of hydrolysis is 4.35% free amino content when the maximum is 4.5 mmol·L-1. The research results provide a theoretical basis for the development of reeling wastewater utilization, and provide reference value for the subsequent development of new protein-based surfactants.