Changes in the profile of free amino acids and biogenic amines during the extended short ripening of Portuguese dry-cured ham

Portuguese dry-cured hams were evaluated according to the profile of free amino acids and biogenic amines formation during an extended industrial short ripening process (5-12 months). The highest content of free amino acids was reached on the seventh month of curing. Major increases in content were in lysine, glutamic acid and arginine. The levels of biogenic amines-putrescine, cadaverine, histamine, tyramine, spermidine and spermine-analysed by reverse-phase HPLC with UV detection, showed wide fluctuations and variability during the ripening period studied. Spermine and cadaverine tended to be present in larger quantities, whereas histamine and spermidine contents were usually low. Spermine was the only amine detected in all samples analysed. Total biogenic amine contents were significantly higher on the ninth and tenth month of ripening, although the levels seemed to be too low to produce toxicological effects.