Synergistic antimicrobial activities of plant essential oils against Listeria monocytogenes in organic tomato juice

One of the most important challenges in the food industry is to provide healthy and safe food. Therefore, it is not possible to achieve this without different processes and the use of various additives. In order to improve safety and extend the shelf life of food products, various synthetic preservatives have been widely utilized by the food industry to prevent growth of spoilage and pathogenic microorganisms. On the other hand, consumers' preference to consume food products with natural additives induced food industries to use natural-based preservatives in their production. It has been observed that herbal extracts and their essential oils could be potentially considered as a replacement for chemical antimicrobials. Antimicrobial properties of plant essential oils are derived from some main bioactive components such as phenolic acids, terpenes, aldehydes, and flavonoids that are present in essential oils. Various mechanisms such as changing the fatty acid profile and structure of cell membranes and increasing the cell permeability as well as affecting membrane proteins and inhibition of functional properties of the cell wall are effective in antimicrobial activity of essential oils. Therefore, our objective is to revise the effect of various essential oils and their bioactive components against Listeria monocytogenes in meat and poultry products.

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Antimicrobial evaluation of plant essential oils against pathogenic microorganisms: In vitro study of oregano oil combined with conventional food preservatives

Acta Universitaria ◽

10.15174/au.2018.1817 ◽

2018 ◽

Vol 28 (4) ◽

pp. 10-18

Author(s):

Zahaed Evangelista-Martínez ◽

Nohemí Reyes-Vázquez ◽

Ingrid Rodríguez-Buenfil

Keyword(s):

Essential Oils ◽

In Vitro Study ◽

Antimicrobial Activities ◽

Food Preservation ◽

Microbial Pathogens ◽

Pathogenic Microorganisms ◽

Food Preservatives ◽

Plant Essential Oils ◽

Oregano Oil

Essential oils (EO) are promising natural antimicrobial additives to control microbial pathogens. This study aims to investigate the antimicrobial activities of plant essential oils and to study the antimicrobial effect of oregano oil (OrO) in combination with food preservatives. The antimicrobial screening showed that Escherichia coli and Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella ser. Typhimurium) appeared to be less susceptible to EO, whereas Staphylococcus aureus and Candida albicans were more affected. The Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) for laurel, cumin, oregano and rosemary oils showed values ranging from 0.078% to 1.25% (v/v). Also, synergic and viability effects of OrO combined with acetic acid (AcA) showed an additive effect against E. coli and C. albicans, while combination OrO + ascorbic acid (Asc) exhibited the same effect over Salmonella ser. Typhimurium and C. albicans. Therefore, oregano oil in combination with preservatives could be used to control the growth of pathogenic microorganisms for food preservation.

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Antimicrobial Activities of Starch-Based Biopolymers and Biocomposites Incorporated with Plant Essential Oils: A Review

Polymers ◽

10.3390/polym12102403 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2403 ◽

Cited By ~ 2

Author(s):

R. Syafiq ◽

S. M. Sapuan ◽

M. Y. M. Zuhri ◽

R. A. Ilyas ◽

A. Nazrin ◽

...

Keyword(s):

Antimicrobial Activity ◽

Tensile Strength ◽

Essential Oil ◽

Essential Oils ◽

Food Packaging ◽

Barrier Properties ◽

Antimicrobial Activities ◽

Food Storage ◽

Plant Essential Oils ◽

Bacteria And Fungi

Recently, many scientists and polymer engineers have been working on eco-friendly materials for starch-based food packaging purposes, which are based on biopolymers, due to the health and environmental issues caused by the non-biodegradable food packaging. However, to maintain food freshness and quality, it is necessary to choose the correct materials and packaging technologies. On the other hand, the starch-based film’s biggest flaws are high permeability to water vapor transfer and the ease of spoilage by bacteria and fungi. One of the several possibilities that are being extensively studied is the incorporation of essential oils (EOs) into the packaging material. The EOs used in food packaging films actively prevent inhibition of bacteria and fungi and have a positive effect on food storage. This work intended to present their mechanical and barrier properties, as well as the antimicrobial activity of anti-microbacterial agent reinforced starch composites for extending product shelf life. A better inhibition of zone of antimicrobial activity was observed with higher content of essential oil. Besides that, the mechanical properties of starch-based polymer was slightly decreased for tensile strength as the increasing of essential oil while elongation at break was increased. The increasing of essential oil would cause the reduction of the cohesion forces of polymer chain, creating heterogeneous matrix and subsequently lowering the tensile strength and increasing the elongation (E%) of the films. The present review demonstrated that the use of essential oil represents an interesting alternative for the production of active packaging and for the development of eco-friendly technologies.

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Antimicorbial Potency of Major Functional Foods’ Essential Oils in Liquid and Vapor Phases: A Short Review

Applied Sciences ◽

10.3390/app10228103 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8103

Author(s):

Azam Amiri ◽

Javad Mottaghipisheh ◽

Fatemeh Jamshidi-Kia ◽

Karamatollah Saeidi ◽

Sara Vitalini ◽

...

Keyword(s):

Essential Oils ◽

Food Processing ◽

Allyl Isothiocyanate ◽

Short Review ◽

Antimicrobial Activities ◽

Food Preservation ◽

Plant Essential Oils ◽

Increasing Risk ◽

Common Plant ◽

Liquid And Vapor Phases

Due to the increasing risk of chemical contaminations in the application of synthetic fungicides, the use of plant essential oils and extracts has recently been increased. In the present review, the antimicrobial potential of the most active plant-food essential oils in liquid and vapor phases has been reviewed. The volatile isothiocyanates, aldehydes, and phenols, including allyl isothiocyanate, carvacrol, thymol, and eugenol, are considered to be the predominant components of essential oils, possessing significant antimicrobial activities. These components alone or in mixture can be effective. Overall, the antimicrobial activity of aroma compounds depends on the plant species, concentration, and method of application. This review provides useful information about the inhibitory application of the most common plant-foods’ essential oils in liquid and vapor phases against the growth of pathogenic microorganisms. Essential oils (EOs) are promising natural antimicrobial alternatives in food processing facilities. Although the food industry primarily uses spices and herbs to impart flavor, aroma, and pungency to foods, potent EOs represent interesting sources of natural products for food preservation.

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Effects of Essential Oils of Oregano and Nutmeg on Growth and Survival of Yersinia enterocolitica and Listeria monocytogenes in Barbecued Chicken

Journal of Food Protection ◽

10.4315/0362-028x-70.11.2626 ◽

2007 ◽

Vol 70 (11) ◽

pp. 2626-2630 ◽

Cited By ~ 42

Author(s):

R. FIROUZI ◽

S. S. SHEKARFOROUSH ◽

A. H. K. NAZER ◽

Z. BORUMAND ◽

A. R. JOOYANDEH

Keyword(s):

Listeria Monocytogenes ◽

Essential Oils ◽

Yersinia Enterocolitica ◽

Pathogenic Bacteria ◽

Culture Media ◽

Broth Culture ◽

Growth And Survival ◽

Plant Essential Oils ◽

Selective Agar

The in vitro effects of plant essential oils (EOs) against pathogenic bacteria are well known, yet few studies have addressed the effects of these compounds against pathogens associated with ready-to-cook foods. Experiments were conducted to determine the effectiveness of oregano and nutmeg EOs on the growth and survival of Yersinia enterocolitica and Listeria monocytogenes in broth culture and in Iranian barbecued chicken. Ready-to-cook Iranian barbecued chicken was prepared according to the common practice with 1, 2, and 3 μl/g of oregano and nutmeg EOs. The test and control (without EOs) samples were inoculated with Y. enterocolitica and L. monocytogenes to a final concentration of 6 to 7 log CFU/g and stored at 3, 8, and 20°C. Microorganisms were counted just before and at 24, 48, and 72 h after storage based on growth on Yersinia selective agar supplemented with cefsulodine, igrasan, and novobiocin and on Listeria selective agar supplemented with nalidixic acid and acriflavin. In the broth culture system, the nutmeg EO had a greater effect on L. monocytogenes (MIC = 0.20 μl/ml) than did the oregano EO (MIC = 0.26 μl/ml). However, the oregano EO had a greater effect on Y. enterocolitica (MIC = 0.16 μl/ml) than did the nutmeg EO (MIC = 0.25 μl/ml). In ready-to-cook Iranian barbecued chicken, the log CFU per gram of both bacteria after up to 72 h of incubation was not decreased significantly by various combinations of oregano and nutmeg EOs (1, 2, and 3 μl/g) and storage temperatures (3, 8, and 20°C) when compared with control samples (without EOs). Although examination of spices in culture media can yield accurate microbiological data, without complementary tests in foods these data are of limited value for assessing food safety.

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Sodium Polyphosphate and Polyethylenimine Enhance the Antimicrobial Activities of Plant Essential Oils

ScienceOpen Research ◽

10.14293/s2199-1006.1.sor-life.z72tp0.v1 ◽

2016 ◽

Author(s):

Heidi Weinkauf ◽

Byron Brehm-Stecher

Keyword(s):

Essential Oils ◽

Antimicrobial Activities ◽

Microbial Pathogens ◽

Human Pathogens ◽

Intrinsic Resistance ◽

Sodium Polyphosphate ◽

Plant Essential Oils ◽

Food Contact Surfaces ◽

Rough Strain ◽

Effective Use

Plant extracts have been used for millennia for treatment of disease, with much recent interest focusing on the antimicrobial activities of plant essential oils (EOs). Although EOs are active against common microbial pathogens, their effective use as topical, environmental or food antimicrobials will require EO-based formulations with enhanced antimicrobial activities. In the present study, two polyionic compounds, sodium polyphosphate (polyP, a polyanion) and polyethylenimine (PEI, a polycation), were evaluated for their abilities to enhance the antimicrobial activities of six EOs against the human pathogens Escherichia coli O157:H7, Salmonella enterica subsp. enterica ser Minnesota, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus and Candida albicans. EOs tested were cinnamon, clove, regular and redistilled oregano and two types of thyme oil. EOs were examined via disk diffusion and broth microdilution, either alone or in the presence of sub-inhibitory levels of polyP or PEI. Both polyP and PEI were found to be effective enhancers of EO activity against all strains examined, and calculation of fractional inhibitory indices for select EO/organism pairings demonstrated that true synergy was possible with this enhancement approach. Experiments with a deep rough strain of S. Minnesota probed the role of the outer membrane in both intrinsic resistance to EOs and enhancement by polyions. The use of polyP and PEI for boosting the antimicrobial activities of EOs may eventually facilitate the development of more effective EO-based antimicrobial treatments for use in applications such as wound treatment, surface disinfection, or as GRAS antimicrobials for use in foods or on food contact surfaces.

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