BACKGROUND AND OBJECTIVE: Emergence of resistant microbial strains due to the consumption of chemical preservatives and medications, as well as uncertainty about the consumption of foods containing synthetic preservatives, have resulted in the growing popularity of natural preservatives. This study aimed to identify the chemichal compounds found in the essence of Persian hogweed (Heracleum persicum) and investigate the antibacterial effects of the essence of this herb on Listeria monocytogenes and Escherichia coli, the most harmful bacteria in food hygiene.

METHODS: In this experimental study, after the extraction of the essential oil of Heracleum persicum by Clevenger, qualitative and quantitative analyses of the constituent compounds were performed via gas chromatography-mass spectrometry (GC-MS) method. In addition, microdilution method was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and the last plate without turbidity was considered as MIC. By culturing the plates without turbidity on brain-heart infusion (BHI) agar, the lowest concentration of the essence to inhibit the growth was determined as MBC.

FINDINGS: In this study, the main components of the essential oil of Heracleum persicum were Hexyl butanoate (25.98%), Octyl 2-methylbutyrate (14.37%), Pentyl-cyclopropane (12.77%) and Octyl isobutyrate (17.82%). Moreover, MIC values for E. coli and Listeria monocytogenes were 5 and 5.2 mg/ml, respectively, and MBC values for each of the bacteria were equal to MIC.

CONCLUSION: According to the results of this study, aliphatic esters are among the main constituents of the essence of Heracleum persicum. Furthermore, the essential oil of this herb exerts antibacterial effects on both these bacteria, and Listeria monocytogenes was observed to be more sensitive to the essential oil compared to E. coli.