Nucleotides and their degradation products during processing of dry-cured ham, measured by HPLC and an enzyme sensor.

The aim of this work was to study how nucleotide degradation during the processing of dry-cured ham is affected when using three types of salting (100% NaCl; 50% NaCl and 50% KCl; 55% NaCl, 25% KCl, 15% CaCl₂ and 5% MgCl₂). Divalent salts in the salting mixture depressed the breakdown rate from the beginning of the process (salting and post-salting) up to the ripening stage (7 months) when the inosine (Ino), hypoxanthine (Hx) and xanthine (X) concentrations matched for the three treatments. The evolution of Hx and Hx+X were analysed by HPLC and an enzyme sensor, respectively, during processing. Time and temperature conditions during the curing time did not affect Hx stability. The usefulness of the enzyme sensor was confirmed and it is a practical tool to determine Hx + X in dry-cured ham, as an index of minimum curing time. A good correlation between enzyme sensor and HPLC data was observed.