Peptidomics as a tool for quality control in dry-cured ham processing

Spanish dry-cured ham is a high quality product whose economic value is mainly given by its curing time. An intense proteolysis takes place throughout the dry-cured processing, which results in the generation of a high amount of peptides and free amino acids responsible for the final quality of dry-cured hams. In this work, a peptidomics approach has been used to study the evolution of peptides throughout the ham dry-curing process, identifying and quantifying the generated peptides in order to define potential quality biomarkers. For this purpose, dry-cured ham extracts at different processing times (0, 2, 3.5, 5, 6.5 and 9 months) were fractionated by size-exclusion chromatography and analysed by nanoliquid chromatography coupled to tandem mass spectrometry. Differences obtained in the relative quantification of peptides by using a label-free methodology were useful to establish differences between processing times, being peptides generated by the degradation of myosin light chain 1 protein mainly responsible for the observed differences during the last stages of curing. In particular, APAPAPAPPKEEKI and PAPAPAPAPAPAPAPPKE, exclusively identified at 9 months of curing, would be potential markers to control the time of curing and thus the final quality of dry-cured hams.The FPI Scholarship BES-2011-046096 from MINECO (Spain) to M.G. and Grants AGL2013-47169-R from MINECO and FEDER funds are acknowledged. The research also received funding from the European Union Seventh Framework Programme FP7-PEOPLE-2013-CIG under Grant Agreement 614281 (HIGHVALFOOD). The JAEDOC-CSIC postdoctoral contract to L.M. co-funded by the European Social Fund is also acknowledged.Peer reviewe