Effect of extended aging of parma dry-cured ham on the content of oligopeptides and free amino acids

The effect of the dry-curing processing time on the release of oligopeptides and amino acids was evaluated with 158 Parma hams subdivided into three groups: ( 1) traditional processing ( 450 days); ( 2) extended processing ( 570 days); and ( 3) extended aging ( 690 days). Most of the oligopeptides and free amino acids detected increased up to the last deadline ( 690 days); a sharp increase of peptides below 400 Da was the main change in most aged hams. In particular, gamma-glutamyl dipeptides showed a remarkable increase during ham extended aging, acting like permanent taste-active compounds, being unsuitable for further enzymatic breakdown. The pH of fresh hams showed negative relationships (P < 0.001) with most peptides. With regard to free amino acids, the pattern was modified by different processing lengths, together with their taste categories, so that the amino acids having monosodium glutamate-like and bitter tastes were enhanced in more aged hams.