The invention relates to compounds with an antihypertensive effect. More in particular, the invention relates to releasing ACE (angiotensin I-converting enzyme)-inhibitory peptides from whey proteins. The invention provides a method for enzymatically producing a protein hydrolysate with angiotensin-converting enzyme (ACE)-inhibitory activity, characterized by treatment of a beta-lactoglobulin (BLG)-containing substrate with a broad-spectrum endoprotease in a first reaction step followed by treatment with a proline-specific endoprotease in a second reaction step. The invention also relates to ACE-inhibitory hydrolysates obtainable according to such a method and use of the hydrolysates.