Anti‐Salmonella Activity of Volatile Compounds of Vietnam Coriander

Essential oil derived from the fresh leaves of Polygonum odoratum Lour was tested for their effects on a foodborne bacterium Salmonella choleraesuis subsp. choleraesuis ATCC 35640 using a broth dilution method. This essential oil showed a significant antibacterial activity against S. choleraesuis at the concentration of 200 µg/mL. Twenty‐five volatile compounds were characterized from this essential oil by GC‐MS, and aldehyde compounds were found abundant and accounted for more than three‐fourths of the essential oil. Among the compounds characterized, dodecanal (C 12 ) was the most abundant (55.5%), followed by decanal (C 10 ) (11.6%). Both alkanals were effective against S. choleraesuis with the minimum growth inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 100 µg/mL. The most potent antibacterial activity against this bacterium was found with two minor compounds, dodecanol (lauryl alcohol) and 2 E ‐dodecenal, both with each MBC of 6.25 µg/mL. Their primary antibacterial action against S. choleraesuis provably comes from their ability to function as nonionic surface‐active agents (surfactants), disrupting the native function of integral membrane proteins nonspecifically. Thus, the antibacterial activity is mediated by biophysical processes. In the case of 2 E ‐alkenals, a biochemical mechanism is also somewhat involved, depending on their alkyl chain length. Copyright © 2015 John Wiley & Sons, Ltd.