A Comparison between Sodium Metabisulfite and Mentha Longifolia L. Essential Oil on Growth Inhibition of Listeria Monocytogenes and Escherichia Coli O157:H7

The utilization of plant essential oils and extracts as antibacterial agents has given specific attention to prevent the growth of pathogenic bacteria. This work aimed to compare the effects of sodium metabisulfite and Mentha longifolia L. essential oil (MEO; 0, 0.5, 1, and 2%) for growth prevention of Listeria monocytogenes and Escherichia coli O157:H7 in peeled giant freshwater prawns under cold storage for two weeks.   The in vitro antimicrobial effect of MEO against L. monocytogenes and E. coli O157:H7 was evaluated using disk diffusion method. In this study, the effect of direct addition of MEO (0, 0.5, 1, and 2%) and sodium metabisulfite 1.25% to prawn samples were evaluated.  The major chemical constituents of MEO were found to be pulegone (47.20%), eucalyptol (22.72%), and menthone (13.44%). The diameter of inhibition zone of MEO against L. monocytogenes and E. coli O157:H7 were determined to be 9.45 ± 0.23 mm and 6.37 ± 0.02 mm, respectively. Our findings indicated that MEO 0.5, 1, and 2% significantly decreased the growth of L. monocytogenes and E. coli O157:H7 in comparison with the control group (P < 0.05). Sodium metabisulfite was more effective than MEO in inhibiting the growth of L. monocytogenes and E. coli O157:H7 added in raw freshwater prawns.  The findings of this work indicate that MEO can successfully prevent the growth of L. monocytogenes and E. coli O157:H7 and improve the safety of raw freshwater prawns under prolonged refrigerated storage.