Purification and Identification of antihypertensive peptides in Spanish dry-cured ham

Novel sequences exhibiting in vitro ACE inhibitory activity as well as in vivo antihypertensive activity were identified from Spanish dry-cured ham. Water soluble peptide extracts from dry-cured ham were purified by size-exclusion chromatography and reversed-phase high performance liquid chromatography and then, further identification of sequences was carried out by nano-liquid chromatography coupled to tandem mass spectrometry. A total of 73 peptide sequences were identified from active fractions presenting 100% homology with different Sus scrofa skeletal muscle proteins. All identified peptides showed Mr between 374 and 1610 and amino acid sequences between 5 and 14 amino acids in length. Considering the low molecular mass and structural requirements for ACE inhibition some of the identified peptides were synthesised and their IC(50) calculated. The most potent peptide was found to be AAATP (IC(50) value of 100 μM). This peptide also showed good in vivo activity because it decreased systolic blood pressure by -25.62 ± 4.5 mmHg (p<0.05) in spontaneous hypertensive rats after 8 h administration. Other sequences yielded a moderate ACE inhibition. Results from this study show that Spanish dry-cured ham may represent a source of natural peptides with potential benefit for human health.