响应曲面法优化酶解条件制备乳源ACE抑制肽

Response Surface Methodology for Optimization of Hydrolysis Conditions for the Production of Milk-derived Angiotensin-I Converting Enzyme (ACE) Inhibitory Peptides

采用响应曲面法优化胰蛋白酶(PTN6.0S)酶解酪蛋白酸钠的工艺条件,制备高活性的血管紧张素转换酶(ACE)抑制肽。利用准确度更高的RP-HPLC法测定酶解产物的ACE抑制率,通过单因素和响应面试验设计,分别考察p H值、温度、时间、底物质量浓度、酶与底物比等因素对A C E抑制肽活性的影响。结果显示:响应曲面法优化酶解条件得到数学模型为:抑制率/%=-11.21347+4.32902A-1.45953B+3.42928C-0.20303D+0.050303AB+0.047422AD+0.14955BC+0.12486BD-0.054526A2-0.079754B2-0.53587C2-0.28096D2,确定最佳工艺条件为pH7.0、温度52.31℃、时间19.44h、底物质量浓度5.91g/100mL、酶与底物比8.37‰,此时ACE抑制率达97.11%。

In our present study, response surface methodology was used to optimize process conditions for the hydrolysis of sodium caseinate by trypsin to prepare highly active angiotensin-I converting enzyme （ACE） inhibitory peptides. ACE inhibi- tory rate was measured by RP-HPLC. One-factor-at-a-time method followed by response surface analysis was used to analyze the effects of pH, temperature, hydrolysis time, substrate concentration, enzyme/snhstrate ratio on ACE inhibitory activity of sodium caseinate hydrolysate. A mathematical model describing the relationship of ACE inhibitory activity of sodium caseinate hydrolysate with temperature （A）, hydrolysis time （B）, substrate concentration （C） and enzyme/substrate ratio （/9） was obtained as follows： Y= -11.21347＋4.32902A-1.45953B＋3.42928C-0.20303D＋0.050303AB＋0.047422AD＋0.14955BC＋0.12486BD-0.054526A^2-0.079754B^2-0.53587C^2-0.28096D^2. The optimum hydrolysis conditions were determined as pH 7.0, 52.31℃, 19.44 h, substrate concentration of 5.91 g/100 mL and enzyme/substrate ratio of 8.37 %0, resulting in an ACE inhibitory rate of 97.11%.