Abstract

During the last decade it has been shown the importance of developing new rapid methods of analysis with the aim to control the elaboration process of meat products in a safety and efficient way. Due to this interest, part of this Thesis has been focused on the development and the application of new and fast nondestructive methods to control the processing of both cooked and dry-cured ham. The role of creatine and creatinine in the chemical and enzymatic reactions that take place during the postmortem period of skeletal muscle makes these compounds to be potential good markers in the cooked and dry-cured ham processes. In the present Thesis, a new, simple and reliable HPLC method based on hydrophilic interaction chromatography (HILIC) has been developed for the simultaneous determination of creatine and creatinine, together with the dipeptides carnosine, anserine and balenine. This method constitutes an interesting alternative to methods currently in use for the analysis of this type of compounds. Due to the fact that creatine conversion to creatinine is influenced by temperature, time, and pH changes, one of the main objectives of this work has been to use the creatinine/creatine ratio as an indicator to assess the effectiveness of the heat treatment in cooked ham processes and the minimum time of ripening of dry-cured hams.
In addition to the changes occurred in compounds related to muscle metabolism, during the processing of dry-cured ham numerous physico-chemical and biochemical reactions, such as the intense proteolisis of the muscular proteins, take place. In relation to this, although there is evidence of the presence of oligopeptides at the end of dry-curing, the identity of these peptides still remained elusive. The present Thesis shows the identification for the first time of a large number of fragments generated from the hydrolysis of myofibrilar proteins like myosin light chain I, titin, and troponin T, and sarcoplasmic proteins like creatine kinase. Modern mass spectrometry-based proteomic approaches have been carried out to reach this objective. 





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