Eur Food Res Technol (2006) 222: 658–666 DOI 10.1007/s00217-005-0196-6 ORIGINAL PAPER Mar´ ıa P´ erez-Juan · M´ onica Flores · Fidel Toldr´ a Generation of volatile flavour compounds as affected by the chemical composition of different dry-cured ham sections Received: 19 July 2005 / Revised: 3 November 2005 / Accepted: 6 November 2005 / Published online: 16 December 2005 C  Springer-Verlag 2005 Abstract The composition of different dry-cured ham sec- tions has been determined in order to study their contribu- tion to flavour generation. The proteins, free amino acids, free fatty acids and volatile compounds were analysed in different sections of dry-cured hams with 7 and 12 months of processing. The main differences among sections were detected in free amino acids and volatile compounds. To sum up, there was a higher concentration of free amino acids in the centre section than in the butt and shank sec- tions. However, after 12 m of ripening the difference among sections was lower and only the butt was the one with the lowest concentration. Similar results were obtained in the content of volatile compounds, the centre part of the hams contained a higher proportion of volatile compounds after 7 m of ripening than the shank and butt sections. Neverthe- less, in 12 months dry-cured hams there are changes in the proportions of volatile compounds being the centre section the one with the highest proportion of volatile compounds due not only to the higher concentration of free amino acids but also to the oxidation of unsaturated fatty acids. Keywords Protein . Free amino acids . Free fatty acids . Volatile compounds . Dry-cured ham . Flavour Introduction The high quality of dry-cured ham depends on its unique flavour developed through the long ripening–drying stage. However, in order to perceive the flavour, volatile com- pounds must be released from the food matrix and trans- ported to the flavours receptors in the mouth and nose [1]. M. P´ erez-Juan · M. Flores () · F. Toldr´ a Instituto de Agroqu´ ımica y Tecnolog´ ıa de Alimentos (CSIC), P.O. Box 73, 46100 Burjassot (Valencia), Spain e-mail: mflores@iata.csic.es Tel.: +34-96-3900022 Fax: +34-96-3636301 In this sense, the volatile compounds generated in dry- cured ham will contribute to the aroma depending on its concentration, odour threshold and on the interac- tion with other food components that will affect its gas phase concentration and therefore, the perceived aroma. Dry-cured ham is a heterogeneous product where dif- ferent sections can be appreciated because of the intra- and inter-muscle variations that exists in animal tissues [2]. Also, dry-cured ham undergoes a salting and dehy- dration process that influences the dynamics of water, sodium chloride and nitrate, nitrite migration [3]. More- over, moisture diffusion is related to meat characteris- tics including temperature, pH, structure and composition [4]. Many studies of dry-cured ham flavour have been done taking into account the anatomical localisation, generally in the centre part of the ham including Biceps femoris, Sem- mimembranosus and Semitendinosus muscles [5–8] or in Biceps femoris [9–11] or in Semmimembranosus muscles [12], because these latest muscles are representative of the inner and outer parts of the ham, respectively. Also, the effect of slice location on sensory characteristics has been study showing an important effect on the texture and ap- pearance while small differences were obtained in aroma and flavour [13]. However, none of these studies have con- sidered the different sections in a ham. In every section, there are biochemical reactions during the drying–curing process that affect proteolysis and lipolysis and contribute to the development of an adequate texture and a char- acteristic flavour [14]. On the other hand, the different sodium chloride content and moisture in the sections af- fect the enzyme activity responsible for different amounts of flavour precursors and finally, this enzyme activity will affect the degradation of the matrix. Therefore, the aim of this study was to determine how the biochemical struc- ture (proteins and lipids) and their degradation products af- fects the content of volatile compounds in different sections of the ham in order to study their contribution to flavour generation.