Chemical composition,antibacterial activity of Cyperus rotundus rhizomes essential oil against Staphylococcus aureus via membrane disruption and apoptosis pathway

The chemical composition, antibacterial activity and mechanism of essential oil from Cyperus rotundus rhizomes against Staphylococcus aureus were investigated in this study. Results showed that α-cyperone, cyperene and α-selinene were the major components of the essential oil. The essential oil exhibited strong antibacterial activity against S. aureus with the minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) were 10 and 20 mg/mL respectively, and the antibacterial effects increased with increasing essential oil concentrations and treatment time. The electric conductivity, cell membrane integrity, NPN uptake, and membrane potential assays demonstrated that essential oil disrupted the membrane integrity of S. aureus. Electron microscope observations further confirmed that essential oil destroyed cell membrane. Moreover, we found that essential oil could induce cells death of S. aureus through apoptosis pathway based on apoptosis analysis. These findings suggested that essential oil mainly exerted antibacterial activity by damaging cell membrane and membrane-mediated apoptosis pathway.     

Antibacterial activity and mechanism of cinnamon essential oil against Escherichia coli and Staphylococcus aureus

Cinnamon essential oil (EO) exhibited effective antibacterial activity against foodborne spoilage and pathogenic bacteria in model systems using Escherichia coli and Staphylococcus. The minimum inhibition concentration (MIC) of cinnamon EO was similar for both bacteria (1.0 mg/ml) while the minimum bactericide concentration (MBC) were 4.0 mg/ml and 2.0 mg/ml for E. coli and Staphylococcus aureus. GC–MS analysis confirmed that cinnamaldehyde was the major constituent in cinnamon EO (92.40%). Much effort was focused on elucidating the mechanism of antibacterial action of cinnamon EO against E. coli and S. aureus by observing the changes of cell microstructure using scanning electron microscope, determination of cell permeability, membrane integrity and membrane potential. After adding cinnamon EO at MIC level, there were obvious changes in the morphology of bacteria cells indicating cell damage. When cinnamon EO were added at MBC levels, the cells were destroyed. Cinnamon EO led to leakage of small electrolytes, causing rapid increase in the electric conductivity of samples at the first few hours. The values for E. coli and S. aureus reached 60% and 79.4% respectively at 7 h. Moreover, the concentration of proteins and nucleic acids in cell suspension also rose with increased cinnamon EO. Bacterial metabolic activity was decreased 3–5 folds as reflected by the results of membrane potential. Overall, S. aureus was more susceptible to cinnamon EO than E. coli.     

Antibacterial activity and mechanism of pinoresinol from Cinnamomum Camphora leaves against food-related bacteria

Pinoresinol from the leaves of Cinnamomum camphora used as a model natural compound was extracted and isolated. The chemical characterization of the compound was confirmed using UV, IR, MS, H NMR and C HMR. The purity of the compound (86%) was determined using HPLC technique and it was used for further experiments. Its antibacterial activities against five food-related bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Salmonella enterica) were detected using both broth dilution method and disk diffusion method. Results indicated that 62.5 μg/mL pinoresinol completely inhibit the growth of five bacteria. Much effort was focused on elucidating the mechanism of antibacterial action of pinoresinol against P. aeruginosa and B. subtilis by determination of cell permeability and observing the changes of cell microstructure using scanning electron microscope (SEM). The leakage of the soluble saccharides and proteins were detected and up to 13.89 and 21.76 μg/mL, respectively for P. aeruginosa and 11.08 and 19.05 μg/mL, respectively for B. subtilis. Measurements of the release of the soluble saccharides and proteins confirmed the disruptive action of pinoresinol on cytoplasmic membrane. The damages of the pinoresinol on cell wall were confirmed using Gram staining and scanning electron microscopy (SEM). We concluded that the antibacterial action mechanism of the pinoresinol is attributed to the physiological and morphological changes in bacterial cells.     

Antibacterial activity of two Phlomis essential oils against food pathogens

Phlomis species from the Lamiaceae family are widely distributed in Turkey. In this study, the essential oils of Phlomis russeliana (Sims.) Bentham and Phlomis grandiflora H.S. Thompson var. grandiflora collected from North and Southern parts of Turkey, were obtained by hydrodistillation of the aerial parts. The essential oils were subsequently analysed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC/MS). The major constituents of P. russeliana essential oil were identified as sesquiterpenes β-caryophyllene (23%), germacrene-D (15%), and caryophyllene oxide (8%). Analysis of P. grandiflora var. grandiflora oil also showed oxygenated sesquiterpenes such as β-eudesmol (42%) and α-eudesmol (16%) as major constituents.Furthermore, essential oils were tested in vitro against common food borne bacteria such as Aeromonas hydrophila, Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhimurium, Yersinia enterocolitica, and the anaerobic pathogen Clostridium perfringens using the micro-broth dilution assay. When compared with antimicrobial standards weak to moderate (125 to >1000 μg/ml) minimum inhibitory concentrations (MIC) were observed. The results show that Phlomis essential oils might be an alternative to conventional antimicrobials in various foods.     

Antifungal, aflatoxin inhibition and antioxidant activity of Callistemon lanceolatus (Sm.) Sweet essential oil and its major component 1,8-cineole against fungal isolates from chickpea seeds

The present investigation reports the extent of molds and aflatoxin contamination to Avarodhi, Kabuli, Pusa 256, Radha and Samrat varieties of chickpea seeds. The study also examines the chemical composition of Callistemon lanceolatus (Sm.) Sweet essential oil and its antifungal, antiaflatoxin and antioxidant activity. During standardization of chemical profile, a total of 8 compounds constituting 0.862 mg/mL of oil composition were analyzed by GC-MS analysis where 1,8-cineole was recorded as a major component (0.56 mg/mL). The antifungal activity of EO and 1,8-cineole was evaluated by contact assay on Czapek’s dox agar. The EO (0.227-0.908 mg/mL) and 1,8-cineole (0.918 mg/mL) showed remarkable antifungal effect against all the fungal isolates of chickpea. Their minimal inhibitory (MIC) and fungicidal (MFC) concentrations for Aspergillus flavus were lower than those of the prevalent systemic fungicide Nystatin. Aflatoxin B₁ (AFB₁) production by NKD-208 isolates of A. flavus was strongly inhibited even at the lower fungistatic concentration of EO and 1,8-cineole.There was no adverse effect of EO treatment on chickpea seed germination suggesting its non-phytotoxic nature. Based on the findings of present investigation, C. lanceolatus essential oil may be recommended as botanical preservative for the enhancement of shelf life of food items in- view of the adverse effect of synthetic preservatives and its strong antifungal, aflatoxin inhibition and antioxidant activity.     

Antibacterial activity of essential oils and their main components enhanced by atmospheric RF plasma

The antibacterial activity of low concentration clove oil, sweet basil oil, and lime oil (5–20 μl ml⁻¹) and their main components (eugenol, β-ocimene, and d-limonene) at the same concentration was enhanced by atmospheric RF plasma at 20W and 40W for 10 min to effectively control the growth of Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus on chicken egg. Number of colony germination after plasma treatment was evaluated. Results showed that growth of E. coli, S. thyphimurium, and S. aureus on eggshell mixed with clove oil (10 μl ml⁻¹) or its main component (eugenol at 5 μl ml⁻¹) was completely inhibited after using plasma treatment at 40W. Without the plasma treatment, all essential oils and all their main components at concentrations of 5–20 μl ml⁻¹ could not inhibit bacterial growth. Thus, this study has demonstrated the good potential of using atmospheric RF plasma treatment to enhance the antibacterial activity of essential oil at a relatively low concentration.     

Essential oil composition and biological/pharmacological properties of Salmea scandens (L.) DC

Salmea scandens (L.) DC is an indigenous edible plant whose stem bark is traditionally used as food by people of Oaxaca, México. Proximate analysis of the edible stem bark revealed abundant amounts of fiber (43.67%) and protein (9.27%). GC and GC-MS analyses demonstrated that the essential oil from leaves contained high levels of germacrene D (47.1%) and elemol (15.3%), whereas that of the stem bark contained the alkylamides N-Isobutyl-(2E,4E,8Z,10E/Z)-dodecatetraenamide isomers (39.7%). Levels of these compounds in the essential oil from both organs were in similar concentrations in all seasons except winter. The HPLC purified N-Isobutyl-(2E,4E,8Z,10E/Z)-dodecatetraenamide isomers produced a non-competitive inhibition on porcine pancreatic lipase. The enzymatic assays with these compounds revealed a modification on V_max (0.0431–0.0533 mM min⁻¹) whereas the K_m value (0.880–0.881 mM) was not significantly changed. Essential oil from the stem bark showed a high anti-microbial activity against some phytopathogenic microorganisms. The MIC's in μg mL⁻¹ for Pseudomonas syringae pathovars were tabaci 56.1, tomato 91.2 and phaseolitica 196.4, for Clavibacter michiganensis 35.8 and Erwinia carotovora 48.1. The fungi Fusarium oxysporum and Phytophthora infestans had MIC's in μg mL⁻¹ of 3.3 and 2.4 respectively. Same essential oil was highly effective against larvae from Aedes aegypti (LC₅₀ = 0.3 μg mL⁻¹) and Anopheles albimanis (LC₅₀ = 2.5 μg mL⁻¹).     

Curcuma longa L. essential oil composition,antioxidant effect,and effect on Fusarium verticillioides and fumonisin production

Essential oils may be an alternative to the use of synthetic fungicides for the control of fungi involved in agricultural product deterioration. The aim of the present study was to evaluate the composition and antioxidant effect of turmeric essential oil and its antifungal and antimycotoxigenic action on Fusarium verticillioides (Sacc.) Nirenberg. The essential oil major components were α-turmerone (42.6%), β-turmerone (16.0%) and ar-turmerone (12.9%). The half-maximal inhibitory concentration (IC₅₀) for the radical scavenging capacities of 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were 0.54 and 10.03 mg/ml, respectively, indicating good antioxidant activity. The application of 17.9 and 294.9 μg/ml of turmeric essential oil decreased the development of F. verticillioides by 56.0 and 79.3%, respectively, when compared with the fungal control. The scanning electron microscopy demonstrated that the oil decreased the thickness and the length of the microconidia. Ergosterol production significantly decreased (p < 0.05) in groups treated with the essential oil relative to the control, indicating an effect of the oil on fungal biomass. The production of B₁ and B₂ fumonisins was significantly inhibited (p < 0.05) in groups treated with the essential oil. The results suggest that turmeric essential oil has antioxidant, antifungal and antimycotoxigenic activities.     

Essential oils composition and bioactivities of two species leaves used as packaging materials in Xishuangbanna,China

This study reports the essential oils chemical composition and antioxidant and antimicrobial potentials of the leaves of Phrynium pubinerve Blume and Thysanolaena latifolia (Roxb. ex Hornem.) Honda, which are used as natural packaging materials by ethnic groups in Xishuangbanna, southwest China. GC–MS analysis identified 46 and 21 components, representing 88.6% and 93.4% of the essential oils of P. pubinerve and T. latifolia, respectively. The major constituents for P. pubinerve were (Z)-3-hexen-1-ol (17.31%), (E)-2-hexenal (9.01%) and 1-hexanol (8.61%). The major constituents for T. latifolia were (Z)-3-hexen-1-ol (28.79%), phytol (12.30) and (E)-β-ionone (9.54%). Both the essential oils and ethanol extracts showed antioxidant activity in DPPH test (IC₅₀ values = 192.47–706.07 μg/ml), ABTS assay (IC₅₀ values = 35.54–134.97 μg/ml) and FRAP assays. The essential oils showed considerable antimicrobial activity against pathogenic bacteria and spoilage organisms, with MIC and MBC values in the ranges of 64–3072 μg/ml and 64–4096 μg/ml, respectively. The bioactivities of these two plant species validate the traditional use of these two plants, suggesting that both could be new sources of natural antioxidant and antimicrobial agents for the packaging, medical and functional food industries.     

Antifungal activity of thyme, summer savory and clove essential oils against Aspergillus flavus in liquid medium and tomato paste

Antifungal activity of essential oils of thyme, summer savory and clove were evaluated in culture medium and tomato paste. Aspergillus flavus were inoculated in Sabouraud Dextrose Broth and tomato paste and then 0, 50, 200, 350 and 500 ppm of essential oils were added to each sample and then kept at 25 ± 0.5 °C for 2 months. Results showed that all essential oils could inhibit the growth of A. flavus and the thyme oil and summer savory, showed the strongest inhibition at 350 ppm and 500 ppm, respectively. Taste panel evaluations were carried out in a tomato ketchup base, and the percent of inhibition of each essential oil in tomato paste was lower than culture medium. Taste panel was carried out and sample with 500 ppm thyme oil was accepted by panelists.     

Synergistic action between fractions of essential oils from Cymbopogon citratus, Ocimum gratissimum and Thymus vulgaris against Penicillium expansum

Penicillium expansum is a mould that causes the rotting of several fruits and vegetables, especially apples onto which it also synthesizes some dangerous mycotoxins. The degree of synergism between fractions of essential from Cymbopogon citratus, Ocimum gratissimum and Thymus vulgaris was evaluated against two mycotoxin producing strains of P. expansum. The antifungal activity determined by dilution method and expressed as a Number of Decimal Reduction of the colony forming units per ml (NDR cfu) showed that the essential oils extracted from O. gratissimum was significantly (P < 0.05) more active against P. expansum than those extracted from C. citratus and T. vulgaris. Fractions enriched with oxygenated terpenes were significantly (P < 0.05) more active than their respective essential oils, whereas most of the fractions enriched with terpene hydrocarbons, were significantly (P < 0.05) less active. The fungicidal activity of mixtures of fractions from the same essential oils or from two different essential oils showed that there exist synergistic, additive and antagonistic effects between fractions of the three essential oils tested against both fungal strains. The synergistic effects observed could be exploited in order to maximize the antimicrobial activity of essential oils and to minimize the concentrations of essential oil required to produce a given antimicrobial effect without any alteration of the food test.     

Antifungal activity of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.) and orange (Citrus sinensis L.) essential oils

The objective of this work was to study the effect of the essential oils of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.) and orange (Citrus sinensis L.) on the growth of moulds commonly associated with food spoilage: Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum and Penicillium verrucosum, using the agar dilution method. All the oils showed antifungal activity against all the moulds. Orange essential oil was the most effective against A. niger, mandarin essential oil was most effective at reducing the growth of Aspergillus flavus while grapefruit was the best inhibitor of the moulds P. chrysogenum and P. verrucosum. Citrus essential oils could be considered suitable alternatives to chemical additives for use in the food industry.     

Assessment of polyphenolic profile and antibacterial activity of pomegranate peel (Punica granatum) flour obtained from co-product of juice extraction

The aim of this work were to determine the polyphenolic profile and the antibacterial properties of pomegranate peel flour (PPF), in view to its application in the food industry as potential antimicrobial “natural” agent. For thus, the antibacterial properties of PPF were tested against: Listeria monocytogenes, Listeria innocua, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Salmonella sp. bacterial strains. The polyphenolic profile was determined by HPLC. The Total Phenolic and Total Flavonoid content were also determined. The HPLC analysis of the PPF, showed a total of eight phenolic compounds. Punicagalin was the main component found in PPF (16.67 mg/g) followed by ellagic acid (0.15 mg/g). PPF had antibacterial activity against all bacteria tested with minimal inhibitory concentrations comprised between 20 and 50 mg/mL. The antimicrobial activity was in a decreasing order: Salmonella sp = E. coli = S. aureus = L. monocytogenes > P. aeruginosa > L. innocua. The antibacterial properties of pomegranate peel flour suggested that it is a promising antibacterial agent.     

Influence of emulsifier type on the antifungal activity of cinnamon leaf,lemon and bergamot oil nanoemulsions against Aspergillus niger

Only exiguous data are currently available on the antifungal properties of essential oil (EO) nanoemulsions against spore-forming microorganisms. The aim of this work is to develop physically stable nanoemulsion-based delivery systems for different EOs (cinnamon leaf, lemon, and bergamot), to exploit their antifungal properties against Aspergillus niger. The inhibition of mycelial radial growth and spore germination were used as indicators of antifungal activity of the nanoemulsions, which were prepared at 3 wt% EO, using non-ionic Tween 80 (T80) or anionic whey protein isolate (WPI) (1 wt%) as emulsifiers, and sunflower oil (1 wt%) as ripening inhibitor. The nanoemulsions were physically stable over seven days of accelerated aging at 35 °C.The minimal inhibitory concentration of free cinnamon leaf and of both citrus EOs were 0.35 and 5.50 μg/g, respectively. The encapsulation of cinnamon leaf EO in nanoemulsions significantly enhanced the inhibiting effect against A. niger mycelial growth and spore germination, with respect to the free EO. In contrast, for citrus EOs, the encapsulation in nanoemulsions generally decreased the antifungal activity, likely because of the nanoemulsion acting as a hydrophobic sink for the main constituents of citrus EOs. The emulsifier played a fundamental role in the resulting antifungal activity, with WPI-based nanoemulsions being more effective in inhibiting the mycelial growth and the spore germination of A. niger than T80-based ones. The antifungal action was correlated to the morphological alterations observed in A. niger, such as the loss of cytoplasm in fungal hyphae and hyphal tip. The results of this study show the importance of nanoemulsions design in the development of efficient and stable natural antifungal agents for food applications.     

Investigation of antibacterial activity of new classes of essential oils derivatives

Essential oils (EOs) have deserved much attention in the past decades for their antimicrobial activity, since many of them have demonstrated efficacy against food-borne pathogenic and spoilage microorganisms. Moreover, they have potential application in animal nutrition as multifunctional feed supplements, avoiding or diminishing the use of antibiotics in livestock. However, low solubility and bioavailability as well as volatility and marked aromatic note are important limitations in food and feed applications. In this study we present the synthesis, characterization and evaluation of the antibacterial activity of new thymol, carvacrol and menthol derivatives. The new compounds have been designed to overcome the limitations of the precursors, such as poor water solubility and volatility, still maintaining a good antimicrobial profile. We evaluated the activity of the synthetized compounds against pathogens causing important foodborne diseases, i.e. Clostridium perfringens, Salmonella typhimurium, Salmonella enteritidis and Escherichia coli. The low MICs and MBCs values for some of the studied compounds, combined with water solubility and negligible cytotoxicity towards HT-29 human cells, confirmed the potential use for EOs derivatives in the food industry.     

Synthesis,surface activity,and composition of dimeric petroleum sulfonates from low quality hydrocarbon feedstock

In the article we discuss the results of a comparison of interfacial activity and component composition data for petroleum sulfonates (PS) synthesized from an extract of selective N-MP refining of side stream II and for dimeric PS prepared from the same source in the presence of paraform (paraformaldehyde)—a component responsible for the formation of disulfonic acids. The prepared technical anionic PS are characterized by a higher molecular mass (688 g/mol) and lower CMC values (40-fold for the mass 120 concentration and 500-fold for the molar concentration) relative to paraform-free sulfonation of hydrocarbons. Surfactants with low CMC values sourced from the low-quality multitonnage hydrocarbon feedstock are promising in a search of formulations for chemical flooding of reservoirs.     

In vitro and in vivo activity of essential oil from dill (Anethum graveolens L.) against fungal spoilage of cherry tomatoes

The objectives of present study were to determine the antifungal activity in vitro of the essential oil extracted from the seeds of dill (Anethum graveolens L.) and to evaluate its antifungal activity in vivo as a potential food preservative. The antifungal activity of this oil was tested by poisoned food technique against Aspergillus flavus, Aspergillus oryzae, Aspergillus niger and Alternaria alternata. The wet and dry mycelium weight of the tested fungi was also determined in a liquid culture to evaluate the antifungal activity. The minimum inhibitory concentration of oil for the four tested fungi was found to be 2.0 μl/ml, and the mycelial growth inhibition was determined at day 9. Observations on the microstructure of A. niger using light and scanning electron microscopes revealed degenerative alterations in the conidial heads and hyphal morphology after oil treatment, including distorted conidial heads, decreased hyphal diameters, shriveled hyphal aggregates, and swelling of the hyphal wall. The effect of the essential oil on inhibition of decay development on cherry tomatoes was tested in vivo by exposing inoculated and control fruit to essential oil vapor at 120 μl/ml and 100 μl/ml concentrations, respectively. Thus, the essential oil of dill could be used to control food spoilage as a potential source of food preservative.     

马朗凹陷芦草沟组页岩油形成机理与富集条件

三塘湖盆地马朗凹陷二叠系芦草沟组源内页岩油的发现对常规油藏勘探理论提出了巨大的挑战。在大量岩心观察、薄片鉴定的基础上,结合地质条件、分析化验、试油情况,深入研究了本区页岩油形成机制与富集条件。研究结果表明,芦草沟组页岩油主要是烃源岩在低熟-成熟早期演化阶段生成的原地滞留原油,页岩油具有高密度、高黏度的物性特点和低饱芳比、高非沥比的族组成特征。页岩油在源岩中的赋存形式主要有两种,即干酪根表面的吸附态及基质孔隙、纹层与水平层面间、微裂缝中的游离态。页岩油大面积连续分布在源岩层中,没有明显的油水界面,油水分异差,产油水比例取决于烃源岩的演化程度,需人工改造才能获得产能,单井产量小但稳产时间长。页岩油富集的控制因素为：①具有生成、储集大量石油的条件;②较好的保存条件,导致大量排烃的断裂不发育。     

Antibacterial activity of plant essential oils and extracts: The role of thyme essential oil,nisin, and their combination to control Listeria monocytogenes inoculated in minced fish meat

Food poisoning caused by Listeria monocytogenes leads to a 30% rate of mortality among patients. The antibacterial activity of cinnamon, thyme, and rosemary essential oils (EOs) and shallot and turmeric extracts was tested against L. monocytogenes using agar well and disc diffusion techniques. Results showed that thyme EO had the highest antimicrobial activity, followed by cinnamon and rosemary EOs, respectively. The antilisterial activity of thyme EO at 0.4%, 0.8%, and 1.2% levels, nisin at 500 or 1000 IU/g level, and their combination against L. monocytogenes was examined in minced fish samples. The antilisterial properties of nisin were also investigated in cooked minced fish treatments. Nisin at 500 or 1000 IU/g in the minced fish meat demonstrated bacteriostatic activity against L. monocytogenes. The use of thyme EO at 0.8% and 1.2% reduced the L. monocytogenes viable count below 2 log cfu/g after 6 days. Furthermore, simultaneous use of thyme EO at 0.8% and 1.2%, and nisin at 500 or 1000 IU/g level, reduced the L. monocytogenes viable count below 2 log cfu/g after the second day of storage. The antilisterial activity of nisin in the cooked minced fish samples was slightly stronger than that of the raw group.     

Evaluation of Zataria multiflora Boiss. essential oil activity against Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes by propidium monoazide quantitative PCR in vegetables

Essential oils (EOs) have long been applied as flavoring agents in foods, and due to their content in antimicrobial compounds, they have potential as natural agents for food preservation. Recently, real-time PCR in combination with PMA has successfully been applied to discriminate between live Escherichia coli O157:H7 and dead bacteria killed by cumin, clove, oregano and cinnamon EOs. In this study, initial experiments were performed in order to elucidate the minimum bactericidal concentration of Zataria multiflora EOs on E. coli O157:H7, Salmonella enterica and Listeria monocytogenes. Thereafter PMA-qPCR was applied in order to selectively quantify life cells within a bacterial population treated with Z. multiflora EO. Inactivation was obtained at EO concentrations of 0.02, 0.035, 0.045 for L. monocytogenes, E. coli O157:H7 and S. enterica, respectively. L. monocytogenes were totally killed in 30 min while it took 1 h 30 min for the gram negative pathogens. As a conclusion Z. multiflora EO has potential as natural food additive or biopreservative since it was able to irreversibly inactivate the three pathogens tested, at lower concentrations than other EOs and short exposition times. In addition, the PMA-qPCR approach proved efficient to selectively detect live pathogenic bacteria in vegetables following inactivation with Z. multiflora EO.