Identification of antioxidant and ACE‐inhibitory peptides in fermented milk

The angiotensin‐converting enzyme (ACE)‐inhibitory activity and antioxidant properties of a commercial fermented milk from Europe were evaluated. This dairy product showed moderate ACE‐inhibitory activity and ABTS•+ radical‐scavenging capacity. The peptides from most active fractions collected by reverse phase high‐performance liquid chromatography (RP‐HPLC) were sequenced by RP‐HPLC–tandem mass spectrometry. This technique allowed rapid identification of peptides included in the most active fractions, and various potentially active peptides were recognised according to previous studies of structure–activity relationship. Three of the identified sequences had previously been described as potent ACE inhibitors. The structure of some sequences substantiated the presence of peptides with ACE‐inhibitory, antioxidant and immunomodulatory activities.