Histamine formation by lipid oxidation products

Formation of histamine from histidine in the presence of lipid hydroperoxides, 2,4-alkadienals, 2-alkenals, 4-oxo-2-alkenals, 4,5-epoxy-2-alkenals, and 4-hydroxy-2-nonenal, and its comparison with the formation of 3-methylhistamine from 3-methylhistidine and β-phenylethylamine from phenylalanine, were studied to investigate the potential contribution of chemical reactions to the formation of biogenic amines during food processing. Amines were mainly produced at acid pH values and their formation was a consequence of carbonyl-amine reactions between the amino acid and the oxidized lipids. Among the different lipid oxidation products assayed, 2,4-alkadienals resulted as the most reactive lipids for this reaction, producing histamine with a low activation energy (22-29 kJ/mol) and a significant yield even at low temperature (1.10 ± 0.15 nmol of histamine/μmol of histidine after 5 weeks at 37 °C). All these results confirm that amino acids can be decarboxylated chemically in the presence of lipid oxidation products at moderated temperatures, and suggest the potential contribution of these reactions to biogenic amine formation in food systems.