Casein, with essential amino acid for individual growth, is the most abundant protein in milk. Recently, many researches demonstrated that casein was not only sources of nutrients, but may also be ones of biologically active peptides, among which ACE inhibitory peptide has received the most attention for its safe and no side effects nature in the therapy of hypertension. In China, there was no study on the production of casein-derived ACE inhibitory peptides thus far. In the present study, optim...