Antibacterial activity of Rosmarinus officinalis L. and Thymus vulgaris L. essential oils and their combination against food-borne pathogens and spoilage bacteria in ready-to-eat vegetables

Abstract

The antibacterial activity of Rosmarinus officinalis L. and Thymus vulgaris L. essential oils (EOs), and their combination against food-borne and spoilage bacteria (Listeria monocytogenes, Salmonella enteritidis, Yersinia enterocolitica, Escherichia coli and Pseudomonas spp.) was determined. The EOs inhibitory effect was evaluated both in vitro by using the disk diffusion assay and the minimum inhibitory concentration (MIC) determination, and on food by using an artificially contaminated ready-to-eat (RTE) vegetables. The results showed that the lowest MIC values were obtained with R. officinalis and T. vulgaris EOs against E. coli (4 and 8 μL/mL, respectively). The incorporation of the EOs alone or their combination in RTE vegetables reduced the viable counts of all the tested strains. Lastly, in the on food study we simulated the worst hygienic conditions, obtaining results that can be considered a warranty of safety.

Combined antimicrobial use of essential oils and bacteriocin bacLP17 as seafood biopreservative to control Listeria monocytogenes both in planktonic and in sessile forms

“…It seems that the EOs are more effective in vegetables because they have a lowfat content [49]. T. vulgaris EO confirmed its good anti-Listeria effect observed in our previous investigation, where this essential oil led to a significant decrease in L. monocytogenes NCTC 10888 cell viability after 4 days of exposure and to a final reduction of 3 log cfu/g in artificially contaminated RTE vegetable, stored at refrigeration temperatures [29]. Another study [50] has shown a lot of pharmacological properties of S. officinalis, with its biological activity attributed to terpenes and terpenoids, compounds extensively found in the plant.…”

New Tricks for Old Guys: Recent Developments in the Chemistry, Biochemistry, Applications and Exploitation of Selected Species from the Lamiaceae Family

“…The addition of oregano essential oil (0.4 % v/w) increased lag phase and decreased growth rates of lactic acid bacteria natural microbiota under isothermal conditions extending shelf‐life of vacuum‐packed cooked sliced ham . Rosemary EO showed interesting antibacterial activity in several food model experiments conducted on thermally processed chicken meat, ready to eat vegetables and fish . Antimicrobial edible coatings or films acting as a protective barrier can be used to retard food spoilage, thus extending food shelf life.…”

Evaluación de extracto etanólico de hojas de tomillo Thymus vulgaris como inhibidor de virulencia en Vibrio parahaemolyticus

“…Otro estudio también observó efecto inhibitorio, aunque esto fue a concentraciones superiores a 1.3 mg/ml de extracto con un diámetro de 7.7 mm (Oramadike & Ogunbanwo, 2017), lo que indica que a mayor concentración de T. vulgaris mayor es el diámetro del halo de inhibición (Montero-Recalde et al, 2018). El efecto observado en cada uno de los estudios varía mucho en cuanto a la concentración usada, esto podría ser a causa de la composición fenólica presente en el extracto durante el tiempo de los tratamientos (Quynh & Trang, 2019), por tanto para contrarrestar de manera más eficaz la actividad bacteriana, es necesaria la combinación de moléculas con actividad biológica para neutralizar el crecimiento de bacterias principalmente multirresistente (Iseppi et al, 2019).…”