Changes in the Profiles of Metabolites Originating from Protein Degradation During Ripening of Dry Cured Ham

Abstract

Ripening of dry cured ham involves a high number of complex enzymatic and chemical reactions. Due to long processing time, there is a need for analytical methods that can be applied to monitor the ripening in optimization of process conditions and development of new products. In this study, nontargeted metabolite analysis by mass spectrometry (MS) was employed to determine the ripening rates at different water activities in small-scale laboratory experiments and to follow the progress of the ripening of hams from a dry cured ham production facility. Approximately 1000 metabolites were detected. Of these, 90–95% had molecular masses below 800 Da, and more than 60% below 500 Da. In the order of 150 metabolites were putatively annotated. In addition to free amino acids and muscle metabolites, the nontargeted analysis revealed the time profiles of di- and tripeptides, as well as a high number of compounds generated by further conversion of amino acids, muscle metabolites and probably lipids. Statistical processing of the data sets showed that the metabolite profiles changed with the storage time, and that ripening of fresh and unsalted, dried meat, generated other profiles than salted samples. In conclusion, our approach represents a simple and efficient tool for comparison of process conditions and to follow the time course of the ripening, useful in product development and process optimization.