Aqueous and ethanolic extracts of propolis for the control of tyramine production by food-borne pathogens

The influences of aqueous and ethanolic extracts of propolis (1%) on growth of common Gram-negative (Salmonella Parathyphi A, Campylobacter jejuni, Yersinia enterocolitica and Klebsiella pneumoniae) and -positive (Listeria monocytogenes, Staphylococcus aureus and Enterococcus faecalis) food-borne pathogens and their biogenic amines (BAs) production were examined in tyrosine decarboxylase broth (TDB). The highest growth inhibitory activity was observed against Gram-negative S. Paratyphi A in the existence of ethanolic and aqueous extracts of propolis, with 2.49 and 1.9 log reduction, respectively. Ethanolic extracts of propolis were more effective than that of aqueous extract on growth inhibition of L. monocytogenes (p