Cinnamon Bark Essential Oil Research Articles

Development of an experimental apparatus and protocol for determining antimicrobial activities of gaseous plant essential oils

There is a growing interest in the use of naturally-occurring antimicrobial agents such as plant essential oils (EOs) to inhibit the growth of hazardous and spoilage microorganisms in foods. Gaseous EOs (EO gases) have many potential applications in the food industry, including use as antimicrobial agents in food packaging materials and sanitizing agents for foods and food-contact surfaces, and in food processing environments. Despite the potentially beneficial applications of EO gases, there is no standard method to evaluate their antimicrobial activities. Thus, the present study was aimed at developing an experimental apparatus and protocol to determine the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) of EO gases against microorganisms. A sealed experimental apparatus was constructed for simultaneous evaluation of antimicrobial activities of EO gases at different concentrations without creating concentration gradients. A differential medium was then evaluated in which a color change allowed for the determination of growth of glucose-fermenting microorganisms. Lastly, an experimental protocol for the assessment of MIC and MLC values of EO gases was developed, and these values were determined for 31 EO gases against Escherichia coli O157:H7 as a model bacterium. Results showed that cinnamon bark EO gas had the lowest MIC (0.0391μl/ml), followed by thyme-thymol EO gas (0.0781μl/ml), oregano EO gas (0.3125μl/ml), peppermint EO gas (0.6250μl/ml), and thyme-linalool EO gas (0.6250μl/ml). The order of the MLC values of the EO gases against the E. coli O157:H7 was thyme-thymol (0.0781μl/ml)<cinnamon bark (0.1563μl/ml)<oregano (0.3125μl/ml)<peppermint (0.6250μl/ml)=thyme-linalool (0.6250μl/ml). The experimental apparatus and protocol enable rapid and accurate determination of the MIC and MLC values of EO gases and perhaps other types of gaseous antimicrobial agents.

Antifungal Activity of Three Essential Oils against Colletotrichum acutatum, the Causal Agent of Strawberry Anthracnose

The antifungal effects of thyme, cinnamon bark and clove bud essential oils (EOs) were investigated in vitro on Colletotrichum acutatum mycelial growth, conidial germination, appressoria formation, and in vivo on strawberry fruit disease incidence. All tested EOs, incorporated in potato-dextrose agar, inhibitedC. acutatum mycelial growth, and had a fungistatic effect at concentration 667 µl/l of medium. Volatiles of cinnamon bark, thyme and clove bud EOs completely prevented conidial germination at the lowest concentrations of 1.53, 15.3 and 76.5 µl/l of air, respectively, and disabled appressoria formation at concentration of 1.53 µl/l of air. On inoculated strawberry fruit, thyme and cinnamon bark EO volatiles reduced anthracnose incidence at concentrations above 15.3 and 76.5 µl/l of air, respectively. GC-FID and GC-MS analysis showed that major components of thyme EO were p-cymene, thymol, α-terpineol, carvacrol; cinnamon bark EO: trans- cinnameldehyde, trans-cinnamyl acetate; clove bud EO: eugenol and β-caryophyllene. Our results suggest thatvolatiles of thyme and cinnamon bark EOs are effective against C. acutatum both in vitro and in vivo.

Bioanalytical evaluation of Cinnamomum zeylanicum essential oil

This manuscript describes the antioxidant activity of essential oil of Cinnamon (Cinnamomum zeylanicum) bark extracted by supercritical fluid extraction (SCFE), hydro distillation and steam distillation. The cinnamon bark essential oil exhibited a wide range of total phenolic contents, total flavonoid contents, reducing power, inhibition of linoleic acid peroxidation and DPPH radical-scavenging activity (IC50). Bioactivity of cinnamon essential oil was assayed against various bacterial strains including Bacillus subtilis, Escherichia coli, Pastrurella multocida and Straphylococcus aureus and fungal strains including Aspergillus niger and Aspergillus flavus. More essential oil yield was obtained using SCFE in comparison to other methods. The oil extracted by SCFE was dominated by cinnamaldehyde, limonene, copaene, naphthalene, heptane, bicyclo[4.2.0]octa-1,3,5-triene and 2-propenal. Due to the presence of cinnamaldehyde in the essential oil of cinnamon bark it acts as a good antioxidant and antimicrobial agent.

The effect of essential oils and cinnamaldehyde on the inactivation of Salmonella Enteritidis in liquid egg products: comparison to synthetic additives

This work explores the effect of the addition of rosemary, cinnamon bark and thyme essential oils (EOs) and one of their main active compounds cinnamaldehyde (CNM) on the inactivation of Salmonella enterica serovar Enteritidis in liquid whole egg (LWE), liquid egg white (LEW) and liquid egg yolk (LEY) stored at 4 °C. The method is proposed as an alternative to the use of synthetic additives (sorbic acid and sodium benzoate). The growth/survival of S. Enteritidis was studied by quantitative and presence/absence tests. The cinnamon bark EO showed the strongest antimicrobial activity among all the EOs tested in the egg derivatives; however, its effectiveness was higher in LEW than in LWE and LEY. The antibacterial action of the cinnamon bark oil was attributed mainly to its high content of CNM. Concentrations of 1,000 and 6,000 ppm of CNM were enough to reduce a S. Enteritidis population of 106 CFU ml−1 to undetectable levels in LEW and LWE, respectively. CNM addition did not significantly affect the pH or oBrix of egg products, but the smell and colour of cinnamon were perceptible.

Antibacterial Mode of Action of Cinnamomum verum Bark Essential Oil, Alone and in Combination with Piperacillin, Against a Multi-Drug-Resistant Escherichia coli Strain.

This study aimed to investigate the mechanism of action of the cinnamon bark essential oil (CB), when used singly and also in combination with piperacillin, for its antimicrobial and synergistic activity against beta-lactamase TEM-1 plasmid-conferred Escherichia coli J53 R1. Viable count of this combination showed a complete killing profile at 20 h and further confirmed its synergistic effect by reducing the bacteria cell numbers. Analysis on the stability of treated cultures for cell membrane permeability by CB when tested against sodium dodecyl sulfate revealed that the bacterial cell membrane was disrupted by the essential oils. Scanning electron microscopy observation and bacterial surface charge measurement also revealed that CB causes irreversible membrane damage and reduces the bacterial surface charge. In addition, bioluminescence expression of Escherichia coli [pSB1075] and E. coli [pSB401] by CB showed reduction, indicating the possibility of the presence of quorum sensing (QS) inhibitors. Gas-chromatography and mass spectrometry of the essential oil of Cinnamomum verum showed that trans-cinnamaldehyde (72.81%), benzyl alcohol (12.5%), and eugenol (6.57%) were the major components in the essential oil. From this study, CB has the potential to reverse E. coli J53 R1 resistance to piperacillin through two pathways; modification in the permeability of the outer membrane or bacterial QS inhibition.

Natural Antimicrobial – Containing EVOH Coatings on PP and PET Films: Functional and Active Property Characterization

Natural antimicrobials are currently being tested by many researchers for active packaging applications as a response to consumer demands for safer food products. In previous work, several packaging materials consisting of ethylene vinyl alcohol (EVOH)‐coated polypropylene (PP) films containing essential oils or their constituents as active agents were successfully developed and tested for antimicrobial activity. In this work, selected films from those materials, namely EVOH coatings with carvacrol, citral, marjoram essential oil, or cinnamon bark essential oil, on PP and polyethylene terephthalate (PET) substrates, were subjected to diverse physicochemical analyses in order to assess their suitability for food packaging applications. Concretely, the investigated properties were the stability of EVOH coatings on PP and PET substrates, the retainability of EVOH matrices for active compounds, the mechanical, optical, surface and barrier properties of the final active films and the effects of a matrix modification based on the addition of bentonite nanoclay on the performance of PP/EVOH active packages studied in actual working conditions.Results showed that the application of corona discharge followed by a polyethyleneimine‐based primer was the best anchorage treatment available to stabilize EVOH coatings on PP and PET substrates. Furthermore, they demonstrated that the retention of active agents into EVOH matrices ranged from low to moderate, depending on the embedded substance, and that their presence into an EVOH coating in the final multilayer films did not noticeably affect their mechanical, optical or barrier properties, although it considerably improved their wettability. They also indicated that the inclusion of bentonite nanoparticles into their carrier layers substantially enhanced the performance of the final packages, while maintaining or slightly improving their other physical properties. Hence, as a conclusion, all the assayed multilayer films were considered perfectly valid for food packaging applications, and the incorporation of bentonite nanoclay to their carrier layers was also highly recommended. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Analysis of Essential Oils from Cassia Bark and Cassia Twig Samples by GC-MS Combined with Multivariate Data Analysis

Cinnamomum cassia is one of several species of Cinnamomum which has been widely used as a spice. In this study, the chemical profiles of its bark and twig were characterized by gas chromatography-mass spectrometry (GC-MS) and multivariate data analysis. Principle component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA) of GC-MS data provided a clear separation between those samples. The result obviously showed that the metabolome of cinnamon bark (CB) and cinnamon twig (CT) is different, and the corresponding loading S-plots revealed that the differential metabolites between the essential oils of CB and CT were trans-cinnamaldehyde, trans-anethole, α-cubebene, γ-muurolene, γ-amorphene, δ-cadinene, (−)-calamenene, and o-methoxycinnamaldehyde. Our study demonstrates that the combination of GC-MS spectrum and multivariate data analysis can be applied to identify essential oils from different parts of C. cassia.

Properties of Cassava Starch‐Based Edible Coating Containing Essential Oils

Edible coatings were produced using cassava starch (2% and 3% w/v) containing cinnamon bark (0.05% to 0.30% v/v) or fennel (0.05% to 0.30% v/v) essential oils. Edible cassava starch coating at 2% and 3% (w/v) containing or not containing 0.30% (v/v) of each essential oils conferred increased in water vapor resistance and decreased in the respiration rates of coated apple slices when compared with uncoated fruit. Cassava starch coatings (2% w/v) added 0.10% or 0.30% (v/v) fennel or cinnamon bark essential oils showed antioxidant capacity, and the addition of 0.30% (v/v) of each essential oil demonstrated antimicrobial properties. The coating containing cinnamon bark essential oil showed a significant antioxidant capacity, comparing to fennel essential oil. Antimicrobial tests showed that the addition of 0.30% (v/v) cinnamon bark essential oil to the edible coating inhibited the growth of Staphylococcus aureus and Salmonella choleraesuis, and 0.30% fennel essential oil inhibited just S. aureus. Treatment with 2% (w/v) of cassava starch containing 0.30% (v/v) of the cinnamon bark essential oil showed barrier properties, an antioxidant capacity and microbial inhibition.

Combination of essential oils and antibiotics reduce antibiotic resistance in plasmid-conferred multidrug resistant bacteria

In this study we investigated the relationship between several selected commercially available essential oils and beta-lactam antibiotics on their antibacterial effect against multidrug resistant bacteria.The antibacterial activity of essential oils and antibiotics was assessed using broth microdilution. The combined effects between essential oils of cinnamon bark, lavender, marjoram, tea tree, peppermint and ampicillin, piperacillin, cefazolin, cefuroxime, carbenicillin, ceftazidime, meropenem, were evaluated by means of the checkerboard method against beta-lactamase-producing Escherichia coli. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interaction between the combinations. Substantial susceptibility of the bacteria toward natural antibiotics and a considerable reduction in the minimum inhibitory concentrations (MIC) of the antibiotics were noted in some paired combinations of antibiotics and essential oils.Out of 35 antibiotic-essential oil pairs tested, four of them showed synergistic effect (FIC≤0.5) and 31 pairs showed no interaction (FIC>0.5–4.0). The preliminary results obtained highlighted the occurrence of a pronounced synergistic relationship between piperacillin/cinnamon bark oil, piperacillin/lavender oil, piperacillin/peppermint oil as well as meropenem/peppermint oil against two of the three bacteria under study with a FIC index in the range 0.26–0.5. The finding highlighted the potential of peppermint, cinnamon bark and lavender essential oils being as antibiotic resistance modifying agent. Reduced usage of antibiotics could be employed as a treatment strategy to decrease the adverse effects and possibly to reverse the beta-lactam antibiotic resistance.

Detection of the antibacterial effect of essential oils on outer membrane proteins of Pseudomonas aeruginosa by lab‐on‐a‐chip and MALDI‐TOF/MS

ABSTRACTIn bacteria, structural changes of outer membrane protein (OMP) composition may have an effect on the adhesive ability and pathogenic properties of the organisms. Pseudomonas aeruginosa can develop an intrinsic resistance to a wide range of biocides, which is associated with the nature of its outer membrane. The aim of our study was to examine how the essential oils of cinnamon bark and clove modify the OMP composition of the human pathogen P. aeruginosa strains and to identify the structure of proteins that are considerably changed after incubation with essential oils. Chemical composition of the oils was analysed by using gas chromatography and gas chromatography–mass spectrometry. Eugenol (83.7%) was the main component of the clove oil, while trans‐cinnamic aldehyde (73.2%) was the main constituent in cinnamon bark oil. Values for the minimum inhibitory concentration (MIC) of the oils were determined by a modified tube dilution method. The oils were administered to the culture at concentrations of 0.5 × MIC and 2 × MIC and incubated for 60 min. After OMP preparation, the structure of proteins was analysed by MALDI‐TOF/MS. Cinnamon and clove oil could influence the OMP composition of Pseudomonas strains. Proteins with molecular weights of 42.7 kDa and 79.4 kDa disappeared after treatment with cinnamon and clove oil, respectively. Quantitative changes in the protein profile may contribute to the explanation of the antibacterial effect of cinnamon bark and clove essential oils on pathogenic Pseudomonas strains. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Functional and ultrastructural changes in Pseudomonas aeruginosa and Staphylococcus aureus cells induced by Cinnamomum verum essential oil

To study cellular damage induced by Cinnamomum verum essential oil in Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 29213. The effect of cinnamon bark essential oil on these two strains was evaluated by plate counts, potassium leakage, flow cytometry and transmission electron microscopy (TEM). Exposure to this oil induced alterations in the bacterial membrane of Ps. aeruginosa, which led to the collapse of membrane potential, as demonstrated by bis-oxonol staining, and loss of membrane-selective permeability, as indicated by efflux of K(+) and propidium iodide accumulation. Thus, respiratory activity was inhibited, leading to cell death. In Staph. aureus, cells treated with the oil entered a viable but noncultivable (VNC) state. The oil initially caused a considerable decrease in the metabolic activity and in the replication capacity of these bacterial cells. The loss of membrane integrity appeared later, as indicated by bis-oxonol and Propidium iodide (PI) staining. Data provided by TEM showed various structural effects in response to cinnamon essential oil. In Ps. aeruginosa cells, coagulated cytoplasmic material was observed, and intracellular material was seen in the surrounding environment, while oil-treated Staph. aureus showed fibres extending from the cell surface. Cinnamon essential oil damages the cellular membrane of Ps. aeruginosa, which leads to cell death. There is evidence of VNC Staph. aureus after exposure to the oil. Cinnamon essential oil shows effective antimicrobial activity and health benefits and is therefore considered a potential food additive. To use this oil as a natural food preservative, especially in combination with other preservation methods, a thorough understanding of the mechanism through which this oil exerts its antibacterial action is required.

Short communication: Assessment of the potential of cinnamaldehyde, condensed tannins, and saponins to modify milk fatty acid composition of dairy cows

This study was conducted to determine whether feeding cinnamaldehyde (main component of cinnamon bark essential oil; Cinnamon cassia), condensed tannins from quebracho trees (Schinopsis balansae), or saponins from Yucca schidigera altered the milk fatty acid profile of dairy cows. For this purpose, 4 lactating cows were used in 4 × 4 Latin square design (28-d period) and fed a total mixed ration containing no additive (control), or supplemented with cinnamaldehyde (1 g/d; CIN), quebracho condensed tannin extract (150 g/d; 70% of tannins; QCT), or Yucca schidigera saponin extract (60 g/d; 10% of saponins; YSE). Results revealed no effects of feeding CIN or QCT on milk fatty acid profile. Supplementation with YSE resulted in some modifications of milk fatty acid profile as suggested by the reduced proportions of C6:0 (2.71 vs. 2.95%), C8:0 (1.66 vs. 1.89%), and trans-11 C18:1 (0.92 vs. 1.01%). Results show low potential of cinnamaldehyde, condensed tannins, and saponins to alter ruminal biohydrogenation process and modify the fatty acid profile of milk fat at the feeding rates used in this study. Further investigations are needed to determine the factors that limit the effects of these secondary metabolites on ruminal microbial populations involved in the biohydrogenation processes of unsaturated fatty acids.

Antimicrobial Activity of Clove and Cinnamon Essential Oils against Listeria monocytogenes in Pasteurized Milk

The antimicrobial activity of essential oils (EOs) of cinnamon bark, cinnamon leaf, and clove against Listeria monocytogenes Scott A were studied in semiskimmed milk incubated at 7°C for 14 days and at 35°C for 24 h. The MIC was 500 ppm for cinnamon bark EO and 3,000 ppm for the cinnamon leaf and clove EOs. These effective concentrations increased to 1,000 ppm for cinnamon bark EO, 3,500 ppm for clove EO, and 4,000 ppm for cinnamon leaf EO when the semiskimmed milk was incubated at 35°C for 24 h. Partial inhibitory concentrations and partial bactericidal concentrations were obtained for all the assayed EOs. The MBC was 3,000 ppm for the cinnamon bark EO, 10,500 ppm for clove EO, and 11,000 ppm for cinnamon leaf EO. The incubation temperature did not affect the MBC of the EOs but slightly increased the MIC at 35°C. The increased activity at the lower temperature could be attributed to the increased membrane fluidity and to the membrane-perturbing action of EOs. The influence of the fat content of milk on the antimicrobial activity of EOs was tested in whole and skimmed milk. In milk samples with higher fat content, the antimicrobial activity of the EOs was reduced. These results indicate the possibility of using these three EOs in milk beverages as natural antimicrobials, especially because milk beverages flavored with cinnamon and clove are consumed worldwide and have been increasing in popularity in recent years.