scholarly journals Innovative Antimicrobial Chitosan/ZnO/Ag NPs/Citronella Essential Oil Nanocomposite—Potential Coating for Grapes

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1801
Author(s):  
Ludmila Motelica ◽  
Denisa Ficai ◽  
Anton Ficai ◽  
Roxana-Doina Truşcă ◽  
Cornelia-Ioana Ilie ◽  
...  

New packaging materials based on biopolymers are gaining increasing attention due to many advantages like biodegradability or existence of renewable sources. Grouping more antimicrobials agents in the same packaging can create a synergic effect, resulting in either a better antimicrobial activity against a wider spectrum of spoilage agents or a lower required quantity of antimicrobials. In the present work, we obtained a biodegradable antimicrobial film that can be used as packaging material for food. Films based on chitosan as biodegradable polymer, with ZnO and Ag nanoparticles as filler/antimicrobial agents were fabricated by a casting method. The nanoparticles were loaded with citronella essential oil (CEO) in order to enhance the antimicrobial activity of the nanocomposite films. The tests made on Gram-positive, Gram-negative, and fungal strains indicated a broad-spectrum antimicrobial activity, with inhibition diameters of over 30 mm for bacterial strains and over 20 mm for fungal strains. The synergic effect was evidenced by comparing the antimicrobial results with chitosan/ZnO/CEO or chitosan/Ag/CEO simple films. According to the literature and our preliminary studies, these formulations are suitable as coating for fruits. The obtained nanocomposite films presented lower water vapor permeability values when compared with the chitosan control film. The samples were characterized by SEM, fluorescence and UV-Vis spectroscopy, FTIR spectroscopy and microscopy, and thermal analysis.

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2377
Author(s):  
Ludmila Motelica ◽  
Denisa Ficai ◽  
Ovidiu-Cristian Oprea ◽  
Anton Ficai ◽  
Vladimir-Lucian Ene ◽  
...  

Replacing the petroleum-based materials in the food industry is one of the main objectives of the scientists and decision makers worldwide. Biodegradable packaging will help diminish the environmental impact of human activity. Improving such biodegradable packaging materials by adding antimicrobial activity will not only extend the shelf life of foodstuff, but will also eliminate some health hazards associated with food borne diseases, and by diminishing the food spoilage will decrease the food waste. The objective of this research was to obtain innovative antibacterial films based on a biodegradable polymer, namely alginate. Films were characterized by environmental scanning electron microscopy (ESEM), Fourier-transform infrared spectroscopy (FTIR) and microscopy, complex thermal analysis (TG-DSC-FTIR), UV-Vis and fluorescence spectroscopy. Water vapor permeability and swelling behavior were also determined. As antimicrobial agents, we used silver spherical nanoparticles (Ag NPs) and lemongrass essential oil (LGO), which were found to act in a synergic way. The obtained films exhibited strong antibacterial activity against tested strains, two Gram-positive (Bacillus cereus and Staphylococcus aureus) and two Gram-negative (Escherichia coli and Salmonella Typhi). Best results were obtained against Bacillus cereus. The tests indicate that the antimicrobial films can be used as packaging, preserving the color, surface texture, and softness of cheese for 14 days. At the same time, the color of the films changed (darkened) as a function of temperature and light presence, a feature that can be used to monitor the storage conditions for sensitive food.


Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1303 ◽  
Author(s):  
Do N. Dai ◽  
Nguyen T. Chung ◽  
Le T. Huong ◽  
Nguyen H. Hung ◽  
Dao T.M. Chau ◽  
...  

Members of the genus Cinnamomum (Lauraceae) have aromatic volatiles in their leaves and bark and some species are commercially important herbs and spices. In this work, the essential oils from five species of Cinnamomum (C. damhaensis, C. longipetiolatum, C. ovatum, C. polyadelphum and C. tonkinense) growing wild in north central Vietnam were obtained by hydrodistillation, analyzed by gas chromatography and screened for antimicrobial and mosquito larvicidal activity. The leaf essential oil of C. tonkinense, rich in β-phellandrene (23.1%) and linalool (32.2%), showed excellent antimicrobial activity (MIC of 32 μg/mL against Enterococcus faecalis and Candida albicans) and larvicidal activity (24 h LC50 of 17.4 μg/mL on Aedes aegypti and 14.1 μg/mL against Culex quinquefasciatus). Cinnamomum polyadelphum leaf essential oil also showed notable antimicrobial activity against Gram-positive bacteria and mosquito larvicidal activity, attributable to relatively high concentrations of neral (11.7%) and geranial (16.6%). Thus, members of the genus Cinnamomum from Vietnam have shown promise as antimicrobial agents and as potential vector control agents for mosquitoes.


2010 ◽  
Vol 62 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Tatjana Mihajilov-Krstev ◽  
Dragan Radnovic ◽  
Dusanka Kitic ◽  
Zorica Stojanovic-Radic ◽  
Bojan Zlatkovic

A hydro-distilled oil of Satureja hortensis L. was investigated for its antimicrobial activity against a panel of 11 bacterial and three fungal strains. The antimicrobial activity was determined using the disk-diffusion and broth microdilution methods. The essential oil of S. hortensis L. showed significant activity against a wide spectrum of Gram (-) bacteria (MIC/MBC=0.025-0.78/0.05-0.78 ?l/ml) and Gram (+) bacteria (MIC/MBC=0.05-0.39/0.05-0.78 ?l/ml), as well as against fungal strains (MIC/MBC=0.20/0.78 ?l/ml). The results indicate that this oil can be used in food conservation, treatment of different diseases of humans, and also for the treatment of plants infected by phytopathogens. <br><br><b><font color="red">Detected autoplagiarism. Link to the Editorial Decision <u><a href="http://dx.doi.org/10.2298/ABS1004251U">10.2298/ABS1004251U</a></u></font></b><br>


2008 ◽  
Vol 3 (5) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Ajai Kumar ◽  
Suriya P. Singh ◽  
Sudarshan S. Chhokar

From the seeds of C arum copticum thymol (1) was isolated as the major component and ten derivatives (2–11) were prepared by reacting it with different acid chlorides in a single step. They were evaluated for antimicrobial activity against twelve bacterial strains and nine fungal strains using disc diffusion and broth dilution assays. Derivative 9 was found to be most active against both bacterial and fungal strains.


Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1117
Author(s):  
Shubham Sharma ◽  
Sandra Barkauskaite ◽  
Brendan Duffy ◽  
Amit K. Jaiswal ◽  
Swarna Jaiswal

Bioactive packaging contains natural antimicrobial agents, which inhibit the growth of microorganisms and increase the food shelf life. Solvent casting method was used to prepare the Poly (lactide)-Poly (butylene adipate-co-terephthalate) (PLA-PBAT) film incorporated with the thyme oil and clove oil in various concentrations (1 wt%, 5 wt% and 10 wt%). The clove oil composite films depicted less green and more yellow as compared to thyme oil composite films. Clove oil composite film has shown an 80% increase in the UV blocking efficiency. The tensile strength (TS) of thyme oil and clove oil composite film decreases from 1.35 MPs (control film) to 0.96 MPa and 0.79, respectively. A complete killing of S. aureus that is a reduction from 6.5 log CFU/mL to 0 log CFU/mL was observed on the 10 wt% clove oil incorporated composite film. Clove oil and thyme oil composite film had inhibited E. coli biofilm by 93.43% and 82.30%, respectively. Clove oil composite film had exhibited UV blocking properties, strong antimicrobial activity and has high potential to be used as an active food packaging.


2010 ◽  
Vol 75 (6) ◽  
pp. 739-747 ◽  
Author(s):  
Dinesh Bisht ◽  
Rajendra Padalia ◽  
Lalit Singh ◽  
Veena Pande ◽  
Priyanka Lal ◽  
...  

The essential oils from six Himalayan Nepeta species, viz. Nepeta leucophylla Benth., Nepeta discolor Royle ex Benth., Nepeta govaniana Benth., Nepeta clarkei Hook f., Nepeta elliptica Royle ex Benth. and Nepeta erecta Benth., were tested for their in vitro antimicrobial activity against six pathogenic bacterial and two fungal strains. The results showed that Pseudomonas aeruginosa was the most sensitive strain tested to the essential oils of Nepeta species. The essential oils of N. elliptica and N. erecta exhibited the highest activity against P. aeruginosa, followed by the essential oils of N. leucophylla and N. clarkei. The essential oils from N. elliptica and N. erecta were also found to be very effective against Serratia marcescens; while the essential oil from N. leucophylla displayed significant activity against Proteus vulgaris and Staphylococcus aureus. Other bacterial strains displayed variable degree of susceptibility against one or more of the tested essential oils. The essential oil from N. leucophylla also showed the highest antifungal activity against both tested fungal strains, viz. Candida albicans and Trichophyton rubrum, followed by the essential oils from N. clarkei, N. govaniana and N. erecta. Iridodial derivatives, viz. iridodial ?-monoenol acetate (25.4 %), dihydroiridodial diacetate (18.2 %) and iridodial dienol diacetate (7.8 %) were identified as the major constituents of N. leucophylla, while the essential oils from N. elliptica and N. erecta were dominated by (7R)-trans, trans nepetalactone (83.4 %) and isoiridomyrmecin (66.7 %), respectively. The essential oil of N. discolor was characterized by 1,8-cineole (25.5 %) and ?-caryophyllene (18.6 %), while N. clarkei was dominated by ?-sesquiphellandrene (22.0 %) and germacrene D (13.0 %). Isoiridomyrmecin (35.2 %) and pregeijerene (20.7 %) were identified as the major constituents of N. govaniana. In general the Nepeta species containing constituents with an iridoid or lactone skeleton were found to have the greater antagonistic activity against most of the microbial strains as compared to those containing regular terpene constituents.


2021 ◽  
Vol 20 ◽  
pp. e210219
Author(s):  
Tabata Resque Beckmann Carvalho ◽  
Erich Brito Tanaka ◽  
Amujacy Tavares Vilhena ◽  
Paula Cristina Rodrigues Frade ◽  
Ricardo Roberto de Souza Fonseca ◽  
...  

Aim: This study evaluated the chemical composition of Lippia thymoides (Lt) essential oil and its antimicrobial activity against fungal strains of Candida albicans (Ca) and Gram-negative bacteria Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn). Methods: Lt essential oil was obtained by hydrodistillation apparatus with a modified Clevenger extension. The chemical analysis was analyzed by gas phase chromatography and mass spectrometry on Shimadzu QP 2010 plus. Sample sensitivity evaluation was performed by ABHb-inoculum and culture plates were developed with triphenyltetrazolium chloride, also Fn and Pi samples analysis were in anaerobic environment and Ca sample analysis was performed in aerobic environment. The minimum inhibitory concentration (CIM) was determinated by microdilution in eppendorfs tubes. Results: The chemical analysis showed that Thymol (59,91%) is the main compound found in Lt essential oil, also other antifungal and antimicrobial agents were present γ-terpinene (8.16%), p-cymene (7.29%) and β-caryophyllene (4.49%), Thymol is a central ingredient of many medicinal plants and has a potent fungicidal, bactericidal and antioxidant activity, it has been previously shown to have anti-inflammatory activity against Periodontal Disease (PD) cause can reduces prostanoids, interleukins, leukotrienes levels in periodontium. CIM result Pi was 6.5 μg/mL, Fn was 1.5 μg/mL and Ca was 0.19 μg/mL. Conclusion: The antimicrobial activity of L. thymoides, through the compound Thymol, has been shown promising potential against gram-negative periodontopathogenic bacteria and fungi whose therapeutic arsenal is still very restricted.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Omolbanin Bakhshi ◽  
Ghodsieh Bagherzade ◽  
Pouya Ghamari kargar

Here presented a quick and easy synthesis of copper nanoparticles (CuNPs). Pistachio hull extract has been used as a reducing and stabilizing agent in the preparation of CuNPs. This biosynthesis is a kind of supporter of the environment because chemical agents were not used to making nanoparticles, and on the other hand, it prevents the release of pistachio waste in nature and its adverse effects on nature. The biosynthesized CuNPs and CuNPs/silver Schiff base nanocomposite (CSS NC) were characterized by UV-VIS spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS). CuNP and CSS NC antimicrobial activity was examined by both well diffusion and determination MIC methods against four bacteria Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa and two fungi Aspergillus Niger and Candida albicans. CuNPs and CSS NC showed significant antimicrobial activity on the samples, preventing the growth of bacteria and fungi at very low concentrations. CuNPs and CSS NC had the greatest effect on Escherichia coli bacteria and Aspergillus niger fungi. Phenolic compounds are one of the most important antioxidants that are involved in various fields, including pharmacy. Pistacia vera hull is a rich source of phenolic compounds. In this study, the most phenolic compound in Pistacia vera hull is gallic acid and rutin, which has been identified by HPLC analysis. In this study, Pistacia vera hull essential oil analysis was performed by the GC-MS method, in which α-pinene, D-limonene, and isobornyl acetate compounds constitute the highest percentage of Pistacia vera hull essential oil.


2009 ◽  
Vol 3 (1) ◽  
pp. 103-107 ◽  
Author(s):  
Hend A. Hamedo

Technological application of essential oils, as natural antimicrobial agents, to reduce the effect of pathogenic microorganisms, requires new methods of detection. The present work evaluated the parameters of antimicrobial activity of the essential oils of rosemary (Rosmarinus officinalis) on two pathogenic strains Escherichia coli and Staphylococcus aureus. The MBC and MIC values were of 2.5, 25 μl ml-1, and values of 1.25 and 5 μl ml-1 for the two strains respectively. In this study, an attempt has been made to evaluate randomly amplified polymorphic DNA (RAPD) analysis for its potential to establish antimicrobial effect of rosemary essential oil. For the preliminary assessment, this study compared the effects occurring at molecular levels in E. coli and Staph. aureus exposed to rosemary essential oil at the MIC concentrations for the two organisms. The qualitative modifications arising in random amplified polymorphic DNA (RAPD) profiles as a measure of DNA effects were compared with control which showed many differences. In conclusion, the measurement of parameters at molecular levels is valuable for investigating the specific effects of agents interacting with DNA.


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