The Hurdle Effect of Bunium persicum Essential Oil, Smoke and NaCl for Controlling the Listeria monocytogenes Growth in Fish Model Systems

Application of natural antimicrobial essential oils (EOs) against foodborne pathogens has been recently developed due to consumer demand. In this study, at first step, the highest concentration of Bunium persicum (Black zira) EO without any undesirable effect on sensory properties on fillet was determined, and then the antimicrobial effect of this EO at 0.05, 0.2 and 0.4% against Listeria monocytogenes was examined in fish model systems for 12 days at 4C. Fish peptone broth, kutum broth and cold smoked kutum broth were inoculated with 104cfu/mL L.monocytogenes.Black zira EO demonstrated strong inhibitory activity against L.monocytogenes in fish peptone broth, this efficacy significantly decreased in kutum and cold smoked kutum broth (P<0.05). Black zira EO performance significantly stimulated in broth with 4% NaCl. L.monocytogenes growth rate in cold smoked kutum broth was significantly lower than in kutum broth. Combination of Black zira EO, smoke component, NaCl and low temperature as a Hurdle system has noticeable inhibition on L.monocytogenes growth. Practical Applications L.monocytogenes is one of the most important biological hazards in marine products and control of this foodborne pathogen via application of antimicrobial EOs could have a great impact on safety promotion of sea foods. This study focused on B.persicum (Black zira) because of its pleasant and proper flavor which supports the application of this EO in fish and fish products traditionally from the past times till now. The demonstrated antibacterial activity of B.persicumEO against L.monocytogenes, recommends its application as a natural food preservative. Moreover synergistic effect between NaCl, smoke compounds and the EO in a Hurdle system increased the antibacterial activity of Black zira against L.monocytogenes.