Compositional and degradative changes during the manufacture of dry-cured 'lacon'

The gross and mineral composition, the main physicochemical parameters, the protein extractability and the proteolytic (nitrogen fractions and free amino acids) and lipolytic (acidity index and free fatty acids) changes were studied throughout the manufacturing process of five batches of dry-cured 'lacon', a traditional Spanish meat product made from the fore-ham of the pig following a similar technological process to that of dry-cured ham. The main compositional characteristics of this product are the high NaCl content and the low moisture content at the end of the curing process. The pH remained fairly stable (around 6) throughout the whole process and a fall in a. was observed, reaching very low (0.767 +/- 0.052) final average values. It was noted that 76% of the sarcoplasmic and 83% of the myofibrillar proteins became insoluble during the manufacturing process. The values of the different nitrogen fractions increased in a significant manner during manufacture, reaching low final values that indicate that 'lacon' undergoes a low level of proteolysis in comparison with other products manufactured by similar technologies. The high NaCl content and the intense dehydration suffered during the manufacturing process appear to be the principal causes of this reduced protein degradation. In accordance with the limited increase in the a-amino acidic nitrogen during ripening, the total free amino acid content increased slightly but significantly from average values of 4371 mg kg(-1) dry matter in fresh pieces to average values of 13 020 mg kg-1 dry matter in pieces at the end of the ripening process. The profile of free amino acids in the final product was similar to that observed by other authors in dry-cured ham. The acidity of the fat increased by a factor of five. The final average values (49.9 g oleic acid kg(-1)) were lower than those determined in dry-cured ham, which indicates that 'lacon' undergoes less lipolysis during the ripening process than dry-cured ham. C18:1, C18:2 and C16 were the most intensively released fatty acids during curing. The profile of free fatty acids in the end product was in agreement with that observed by other authors in dry-cured ham. (C) 2003 Society of Chemical Industry.