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

In the present research, the effect of process conditions on the angiotensin-I converting enzyme (ACE) inhibitory activity of whey protein concentrate hydrolysed with crude proteinases preparation from L. helveticus LB13 was investigated systematically using response surface methodology. It was shown that ACE inhibitory activity of the whey hydrolysates 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 were defined using a response surface model. E/S ratio at 0.60, pH at 9.18 and temperature at 38.9 °C were found to be the optimal conditions to obtain high ACE inhibitory activity close to 92.2% and DH of the whey protein was 18.8%.