Antilisterial peptides from Spanish dry-cured hams: Purification and identification

The typical Spanish dry-cured ham has a particular sensory quality that makes it a distinctive food, highly appreciated for consumers worldwide. Its particular physicochemical properties, such as high salt content and reduced water activity contribute to their shelf-stability. However, post-processing actions carried out for the commercialization of these products such as slicing may increase the risk of development of pathogenic microorganisms as Listeria monocytogenes. During ripening, muscle proteins are hydrolyzed by muscle peptidases releasing peptides and free amino acids. Some of these peptides have been described to exert biological activities such as antioxidant and ACE-inhibition. In this study, a peptidomic strategy using mass spectrometry techniques has been used to identify and sequence those naturally generated peptides showing antilisterial activity. One hundred and five peptides have been identified in active fractions and some synthesized and their MIC calculated. Ten peptides were able to inhibit the growth of L. monocytogenes, being the pentapeptide RHGYM the most effective showing a MIC value of 6.25 mM. This study proves for the first time the potential antimicrobial action against L. monocytogenes of certain naturally generated peptides obtained from Spanish dry-cured ham.The postdoctoral fellowship from the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina of P.C. is acknowledged. Grant AGL2013-47169-R from MINECO and FEDER funds as well as HIGHVALFOOD project grant no 614281 from EU-FP7 Marie Curie CIG scheme are fully acknowledged. L.M. is grateful to the JAEDOC-CSIC postdoctoral contract cofunded by European Social Fund.Peer reviewe