School of Food and Biological Engineering, and Institute of Food Physical Processing, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu, PR China.
Food Funct. 2020 May 1;11(5):4403-4415. doi: 10.1039/d0fo00151a. Epub 2020 May 6.
In order to avoid the discomfort of digesting milk protein and make full use of the gastrointestinal digestive function, a milk macromolecular peptide was prepared with ACE inhibitory activity after gastrointestinal digestion as the index. Then, the antihypertensive activity of the milk macromolecular peptide in rats was evaluated. The results showed that the ACE inhibitory activity of hydrolysate after simulated gastrointestinal digestion was the highest in which the degree of hydrolysis was 17% and the ACE inhibitory activity reached 78.48%. The optimum enzymatic parameters were obtained with the protein concentration of 3.4%, enzymatic temperature of 55 °C, pH value of 7.0, and 7% enzyme amount using neutral protease. Under these conditions, the ACE inhibitory activity of hydrolysate after simulated gastrointestinal digestion was as high as 89.49%. Compared to traditional peptides, the ACE inhibitory activity of the macromolecular peptide increased after simulated gastrointestinal digestion. After 4 weeks of gavage tests of the milk macromolecular peptide, the blood pressure of rats with spontaneous hypertension dropped to below 140 mmHg, with a decrease of 60 mmHg. The antihypertensive effect of the milk macromolecular peptide was similar to that of captopril. The milk macromolecular peptide decreased the blood pressure of spontaneously hypertensive rats by inhibiting the ACE activity of the lung, kidney and arteries, and regulating the content of the signal factors of endothelin, NO, angiotensin II and renin in serum indicators. These results indicated that the macromolecular ACE inhibitory peptide with an antihypertensive effect could be prepared by the enzymatic hydrolysis of milk protein to realize the full utilization of protein resources.
为避免消化牛奶蛋白带来的不适，充分利用胃肠道的消化功能，以胃肠道消化后具有 ACE 抑制活性的牛奶大分子肽为指标，制备具有 ACE 抑制活性的牛奶大分子肽，并评价其在大鼠体内的降压作用。结果表明，模拟胃肠道消化后的水解物 ACE 抑制活性最高，其中水解度为 17%时 ACE 抑制活性达到 78.48%。采用中性蛋白酶，当蛋白浓度为 3.4%、酶解温度为 55℃、pH 值为 7.0、酶量为 7%时，可获得最佳的酶解参数。在此条件下，模拟胃肠道消化后的水解物 ACE 抑制活性高达 89.49%。与传统肽相比，大分子肽经模拟胃肠道消化后的 ACE 抑制活性增加。对自发性高血压大鼠灌胃 4 周后，其血压下降至 140mmHg 以下，降低 60mmHg。牛奶大分子肽的降压效果与卡托普利相当。牛奶大分子肽通过抑制肺、肾和动脉中的 ACE 活性，调节血清中内皮素、NO、血管紧张素 II 和肾素等信号因子的含量，降低自发性高血压大鼠的血压。这些结果表明，通过蛋白酶解牛奶蛋白可以制备具有降压作用的大分子 ACE 抑制肽，实现蛋白质资源的充分利用。
