探讨了单酶及双酶分步酶解鸭蛋清蛋白制备多肽的工艺和水解效果。在7种不同来源的蛋白酶中,蛋清水解专用蛋白酶、碱性蛋白酶Alcalase AF 2.4L和胰蛋白酶均显示出了较好的酶解效果,其中以碱性蛋白酶Alcalase AF 2.4L酶解效果最佳,酶解的最佳工艺条件为:底物浓度为50g/L,反应时间4 h,加酶量8.0×104 U/g,pH值8.3、60℃,最大水解度为10.0%;而以蛋清水解专用蛋白酶和胰蛋白酶为催化剂时最大水解度分别为8.8%和7.2%。根据单酶酶解结果探讨了双酶分步酶解工艺,确定了以"蛋清水解专用蛋白酶-碱性蛋白酶Al-calase AF 2.4L"和"碱性蛋白酶Alcalase AF 2.4L-胰蛋白酶"的双酶组合较好,鸭蛋清蛋白在酶解8h后水解度可达到26.2%和26.6%,明显优于单酶水解效果。

The hydrolysis of duck egg-white protein was investigated for preparation of peptides using single and binary-enzymes.Seven kinds of proteases were tested for the hydrolysis of egg-white protein,among which Alcalase AF 2.4L showed the highest catalytic capability.Besides,the egg-white protein-specific protease(SEEP) and trypsin also exhibited high activities in the hydrolysis reaction.By single-factor and orthogonal tests,the optimal conditions for egg white protein hydrolysis were determined as follows: substrate concentration 50 g/L,reaction time 4 hours,enzyme dosage 8.0 ×104 U/g,pH value 8.3,and reaction temperature 60℃,under which the DH values of hydrolysis reactions catalyzed by Alcalase AF 2.4L,SEEP and trypsin were 10.0 %,8.8 % and 7.2 %,respectively.According to the single-enzyme catalyzed hydrolysis,the most suitable binary combinations of proteases were determined as SEEP-Alcalase AF 2.4L and Alcalase AF 2.4L-trypsin.It was found that the degrees of hydrolysis were significantly improved by using SEEP-Alcalase AF 2.4L and Alcalase AF 2.4L-trypsin,being of 26.2 % and 26.6 %,respectively.