Composition and properties of peptides that survive standardised in vitro gastro-pancreatic digestion of bovine milk

There are conflicting results on the release and conservation of bioactive protein sequences during in vitro digestion. Only the peptides that are released and survive may exert their action. Peptides <3 kDa were determined by mass spectrometry after standardised in vitro gastro-pancreatic digestion of bovine milk. At a degree of digestion of 30.7%, 384 peptides were obtained from 2 to 25 residues in length. Five other peptides were recovered after reduction of disulphide bonds. Due to the presence of proline residues at the last or second last position at the C-terminus, a high number of peptides with ACE-inhibitory activity were obtained. Peptides with opioid, antimicrobial, immunomodulatory and antithrombotic activities were recovered, with many precursors and degradative products. Peptides with opioid and antimicrobial activities may be the result of evolutionary processes. The peptides obtained were similar to those released in the human jejunum.