Angiotensin I converting enzyme (ACE) plays an important role in regulation of blood pressure as it converts angiotensin I into angiotensin II (a potent vasoconstrictor). Food protein-derived ACE inhibitory peptides have been considered as a safer alternative to antihypertensive drugs. In our previous study, three ACE inhibitory peptides were characterized from egg white ovotransferrin and their antihypertensive activity has been validated in spontaneously hypertensive rats. However, it is too costly to prepare these peptides from purified egg white ovotransferrin. The aims of the study were to determine the feasibility of preparing these peptides using egg white and then to optimize the conditions of preparing egg white hydrolysate. Taguchi's method was used to design experiments for optimization, which was established as follows: substrate %, pH of thermoase, time of thermoase digestion, ratio of pepsin to substrate, pH of pepsin, temperature of pepsin, and time of pepsin digestion were 7.5%, pH 8, 90 min, 1%, pH 2.5, 55 °C, and 180 min, respectively. The ACE inhibitory activity (IC50 value) and peptide yield obtained under optimal condition were 30 ± 2 μg/mL and 77.5% ± 0.3%, respectively, which were comparable to the predicted values. Hydrolysate prepared at 150 L reactor showed comparable activity but low peptide yield. Results of this study demonstrated the feasibility of using egg white protein as the starting material to prepare a functional ingredient with potent ACE inhibitory activity.

中文翻译：

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具有血管紧张素 I 转化酶抑制活性的蛋清水解物的优化和放大制备

血管紧张素 I 转化酶 (ACE) 在调节血压方面起着重要作用，因为它将血管紧张素 I 转化为血管紧张素 II（一种有效的血管收缩剂）。食物蛋白衍生的 ACE 抑制肽被认为是一种更安全的抗高血压药物替代品。在我们之前的研究中，三种 ACE 抑制肽的特征来自蛋清卵转铁蛋白，它们的抗高血压活性已在自发性高血压大鼠中得到验证。然而，从纯化的蛋清卵转铁蛋白制备这些肽的成本太高。该研究的目的是确定使用蛋清制备这些肽的可行性，然后优化制备蛋清水解物的条件。使用田口的方法设计优化实验，其建立如下：底物%，热酶的pH、热酶消化的时间、胃蛋白酶与底物的比例、胃蛋白酶的pH、胃蛋白酶的温度和胃蛋白酶消化的时间分别为7.5%、pH 8、90分钟、1%、pH 2.5、55°C和180分钟，分别。在最佳条件下获得的ACE抑制活性（IC50值）和肽产量分别为30±2μg/mL和77.5%±0.3%，与预测值相当。在 150 L 反应器中制备的水解产物显示出相当的活性，但肽产量较低。这项研究的结果证明了使用蛋清蛋白作为起始材料制备具有强效 ACE 抑制活性的功能成分的可行性。和 180 分钟，分别。在最佳条件下获得的ACE抑制活性（IC50值）和肽产量分别为30±2μg/mL和77.5%±0.3%，与预测值相当。在 150 L 反应器中制备的水解产物显示出相当的活性，但肽产量较低。这项研究的结果证明了使用蛋清蛋白作为起始材料制备具有强效 ACE 抑制活性的功能成分的可行性。和 180 分钟，分别。在最佳条件下获得的ACE抑制活性（IC50值）和肽产量分别为30±2μg/mL和77.5%±0.3%，与预测值相当。在 150 L 反应器中制备的水解产物显示出相当的活性，但肽产量较低。这项研究的结果证明了使用蛋清蛋白作为起始材料制备具有强效 ACE 抑制活性的功能成分的可行性。