Proteomic identification of antioxidant peptides from 400 to 2500Â Da generated in Spanish dry-cured ham contained in a size-exclusion chromatography fraction

The processing of dry-cured ham results in an intense proteolysis that leads to the generation of peptides of different sizes and composition, which have been shown to be biologically active. In this study, a total of ninety-three peptides mainly derived from actin, β-enolase, myosin heavy chain, and creatine kinase proteins have been identified from a size-exclusion chromatography (SEC) fraction that resulted as antioxidant by using matrix-assisted laser desorption/ionisation time-of-flight (MALDI-ToF) and nESI-ion trap mass spectrometry. Several of the identified peptides have been synthesised and their antioxidant activity tested in vitro by using DPPH radical-scavenging assay and reducing power analysis. The peptide with sequence SNAAC showed the best results with an IC50 of 75.2 μM in DPPH radical-scavenging assay and 205 μM in ferric-reducing antioxidant power analysis, very good when comparing with the positive control 2,6-di-tert-butyl-4-methyl phenol (BHT) that showed an IC50 of 358.5 μM and 90.3 μM, respectively, in the different assays. These results suggest that Spanish dry-cured ham represents an important source of powerful antioxidant peptides which due to their natural characteristics may represent a highly valuable alternative in human health.