响应面法优化核桃ACE抑制肽的制备工艺研究

以核桃分离蛋白为原料,用Neutrase 0.8L酶解制备高活性的ACE抑制肽.采用反相高效液相色谱（RP-HPLC）法测定酶解多肽的ACE抑制率,同时以水解度和ACE抑制率为考查指标,通过单因素试验及响应面试验设计,优化了中性蛋白酶（Neutrase 0.8L）酶解核桃分离蛋白的酶解工艺.结果表明：各因素对水解度的影响顺序为pH〉温度〉E/S,对ACE抑制率的影响顺序为pH〉E/S〉温度;最佳酶解工艺条件为：pH 6.81、温度55℃、时间2h、底物质量浓度2%、酶与底物比3.43%,酶解产物的水解度达到8.52%,ACE抑制率达到67.94%.

Optimisation of hydrolysis conditions for the production of the angiotensin-I converting enzyme(ACE) inhibitory peptides from walnut protein isolate using response surface methodology

In the present research, the effect of process conditions on angiotensin-I converting enzyme （ACE） inhibitory of walnut protein isolate hydrolysed with Neutrase 0.8 L was investigated systematically using response surface methodology, It was shown that degree of hydrolysis （DH） and ACE inhibitory activity of the WPI hydrolysate could be controlled by regulation of three process conditions （hydrolysis temperature, pH and enzyme to substrate （E/S） ratio）. Hydrolysis conditions for optimal ACE inhibition and DH were defined using a response surface model. E/S ratio at 3.43%, pH at 6.81, temperature at 55℃, and enzymolysis time 2 h were found to be the optimal conditions to obtain high ACE inhibitory activity close to 67.94% and DH of WPI hydrolysate can be reached to 8. 52%.