以英红九号红茶渣经碱溶酸沉提取的茶蛋白为研究对象，血管紧张素转化酶（ACE）抑制率为评价指标，通过单因素试验和响应面优化得到茶蛋白ACE抑制肽的最佳制备工艺，并对酶解物进行氨基酸组成分析、超滤膜分离和不同分子量组分的ACE抑制活性分析。结果表明，英红九号茶蛋白ACE抑制肽的最优酶解工艺为酶解温度37 ℃、3.20 h、pH值7.20、底物质量分数3%、酶底质量比0.40%，在此条件下进行的验证试验ACE抑制率为83.38%，与理论值84.48%较相符。英红九号茶蛋白ACE抑制肽酶解物富含必需氨基酸（33.03%）和对ACE抑制活性有重要意义的疏水性氨基酸（47.20%），且经超滤膜分离所得<3 ku组分的ACE抑制活性（IC50=0.85 mg/mL）要显著强于酶解物（IC50=1.37 mg/mL）和>3 ku组分（IC50=2.81 mg/mL）。该研究为食源性ACE抑制肽的研究开发和英红九号茶蛋白的高值化利用提供了理论依据。

Based on tea proteins extracted from Yinghong No. 9 dregs via alkali extraction and acid precipitation, single-factor and response surface designs were used to optimize the preparation of tea-protein angiotensin-converting enzyme (ACE)-inhibitor peptides and maximize the ACE inhibition rate. Protein hydrolysates were subjected to amino acid composition analysis and ultrafiltration membrane separation, and the ACE inhibitory activity of each ultrafiltrated molecular component was analyzed. Enzymolysis conditions of 37 ℃, 3.20 hours, pH of 7.20, substrate mass concentration of 3%, and enzyme-to-substrate mass ratio of 0.40% were found to be optimal for the preparation of ACE-inhibitor peptides and resulted in ACE-inhibitor peptides with an experimentally measured ACE inhibition rate of 83.38%, which is close to the theoretical value of 84.48%. The obtained tea-protein hydrolysate was rich in essential amino acids (33.03%) and hydrophobic amino acids (47.20%), the latter of which is important for ACE-inhibiting activity. Furthermore, the ACE-inhibitory activity of the <3 ku components obtained from ultrafiltration membrane separation (IC50=0.85 mg/mL) is significantly stronger than that of protein hydrolysate (IC50=1.37 mg/mL) and the >3 ku components (IC50=2.81 mg/mL). The findings of this study are expected to serve as theoretical reference for the research and development of food-derived ACE-inhibitor peptides and the value-added utilization of Yinghong No. 9 tea proteins.

安徽农业大学茶树生物学与资源利用国家重点实验室开放课题资助项目（SKLTOF20210104）；广东省茶树资源创新利用重点实验室开放课题（2020KF01）