scholarly journals Rheological and Antimicrobial Properties of Chitosan and Quinoa Protein Filmogenic Suspensions with Thyme and Rosemary Essential Oils

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1616
Author(s):  
Monserrat Escamilla-García ◽  
Raquel A. Ríos-Romo ◽  
Armando Melgarejo-Mancilla ◽  
Mayra Díaz-Ramírez ◽  
Hilda M. Hernández-Hernández ◽  
...  

Food packaging faces the negative impact of synthetic materials on the environment, and edible coatings offer one alternative from filmogenic suspensions (FS). In this work, an active edible FS based on chitosan (C) and quinoa protein (QP) cross-linked with transglutaminase was produced. Thyme (T) and rosemary (R) essential oils (EOs) were incorporated as antimicrobial agents. Particle size, Z potential, and rheological parameters were evaluated. The antimicrobial activity against Micrococcus luteus (NCIB 8166) and Salmonella sp. (Lignieres 1900) was monitored using atomic force microscopy and image analysis. Results indicate that EOs incorporation into C:QP suspensions did not affect the Z potential, ranging from −46.69 ± 3.19 mV to −46.21 ± 3.83 mV. However, the polydispersity index increased from 0.51 ± 0.07 to 0.80 ± 0.04 in suspensions with EO. The minimum inhibitory concentration of active suspensions against Salmonella sp. was 0.5% (v/v) for thyme and 1% (v/v) for rosemary. Entropy and fractal dimension of the images were used to confirm the antimicrobial effect of EOs, which modified the surface roughness.

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Fadi Al-Shoaibi ◽  
Surya Benedicts

This study is aimed to investigate the antimicrobial activity of Garlic, Thyme and Clove essential oils against Micrococcus luteus and Staphylococcus epidermidis. Using natural oils to fight the bacteria will limit the usage of antibiotics, reducing the probability of antibiotic resistance which is a global increasing problem. Also, it will eliminate antibiotic side-effects such as vomiting, diarrhoea and abdominal pain, Which occurs around 1 in 10 people (NHS, 2019). Antibiotics also have an effect the biofilm layer, causing a decrease in immunity. Micrococcus luteus has shown no growth in the trail run when the extracts where undiluted, nor in the main investigation when dilutions took place. This reveals the susceptibility of the bacteria to the following essential oils. Staphylococcus epidermidis has shown to be more resistant than micrococcus luteus. The oils however have produced a diameter of inhibition zone (DIZ), which means the oils are effective. Clove essential oil has produced the smallest inhibition zones in all concentrations carried out, suggesting that it’s the least effective extract. Thyme oil and clove oil have produced similar results; however, Thyme has shown a stronger antimicrobial effect at the 30 and 40% concentrations, whereas garlic has shown a stronger effect using the 20% concentration which has the highest coefficient of variation at 32.00% suggesting that it’s the least precise result.  These results indicate that these essential oils have strong antimicrobial properties suggesting a potential clinical relevance in tackling bacteria.


Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1406
Author(s):  
Rita Cava-Roda ◽  
Amaury Taboada-Rodríguez ◽  
Antonio López-Gómez ◽  
Ginés Benito Martínez-Hernández ◽  
Fulgencio Marín-Iniesta

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 345
Author(s):  
Daniele Valerini ◽  
Loredana Tammaro ◽  
Roberta Vitali ◽  
Gloria Guillot ◽  
Antonio Rinaldi

Porous scaffolds made of biocompatible and environmental-friendly polymer fibers with diameters in the nano/micro range can find applications in a wide variety of sectors, spanning from the biomedical field to textiles and so on. Their development has received a boost in the last decades thanks to advances in the production methods, such as the electrospinning technique. Conferring antimicrobial properties to these fibrous structures is a primary requirement for many of their applications, but the addition of antimicrobial agents by wet methods can present a series of drawbacks. In this work, strong antibacterial action is successfully provided to electrospun polycaprolactone (PCL) scaffolds by silver (Ag) addition through a simple and flexible way, namely the sputtering deposition of silver onto the PCL fibers. SEM-EDS analyses demonstrate that the polymer fibers get coated by Ag nanoparticles without undergoing any alteration of their morphological integrity upon the deposition process. The influence on wettability is evaluated with polar (water) and non-polar (diiodomethane) liquids, evidencing that this coating method allows preserving the hydrophobic character of the PCL polymer. Excellent antibacterial action (reduction > 99.995% in 4 h) is demonstrated against Escherichia coli. The easy fabrication of these PCL-Ag mats can be applicable to the production of biomedical devices, bioremediation and antifouling systems in filtration, personal protective equipment (PPE), food packaging materials, etc.


2017 ◽  
Vol 12 (3) ◽  
pp. 1934578X1701200
Author(s):  
Milica Drobac ◽  
Silvana Petrović ◽  
Marina Milenković ◽  
Maria Couladis ◽  
Jelena Kukić-Marković ◽  
...  

The compositions of hydrodistillated essential oils of Laser trilobum (L.) Borkh. rhizomes and fruits from Serbia, were investigated using GC and GC/MS. In the dark-blue rhizome oil forty-six compounds (93.1% of the total oil) were identified, with α-pinene (31.5%), γ-terpinene (9.0%), p-cymene (7.9%), β-pinene (6.1%) and 1,4-dimethylazulene (6.0%) as the major components. In the colorless fruits oil, twenty components (96.8% of the total oil) were identified, and the main constituents were limonene (51.6%) and perillaldehyde (26.8%). The antimicrobial activity of the oils was tested using the broth microdilution method against nine bacterial and two fungal strains. The oils revealed significant antimicrobial effect, mainly better than that of thymol, used as a reference compound. The strongest activity was recorded for the rhizome oil against Escherichia coli, Klebsiella pneumoniae and Candida albicans (MICs=25 μg/mL), and the fruit oil against C. albicans ATCC 10259 (MIC=12.5 μg/mL).


2013 ◽  
Vol 59 (4) ◽  
pp. 142-156 ◽  
Author(s):  
Mariola Dreger ◽  
Karolina Wielgus

Abstract Nowadays, safety of chemical preservatives has been questioned by a big number of consumers. Traditionally used preservatives often cause skin irritation and lead to allergenic reactions. Growing demands for more natural and preservative-free cosmetics promoted an idea of the replacement of synthetic preservatives with essential oils (EOs) of antimicrobial properties. The antimicrobial effect of essential oil depends on content, concentration and interactions between the main active compounds. Effective preservatives should be characterized by a broad spectrum of antimicrobial activity at a minimum concentration. Formulations containing both types of preservatives: essential oil and a synthetic one have been tested and proposed as a compromise that allows for reducing concentration of both components due to their synergistic activity. Although most essential oils are regarded as safe, some of them may cause risk of contact allergy or phototoxic reaction. A well balanced risk-benefit assessment of essential oils is one of the great challenges for scientists or health policy authorities. This paper presents current state of knowledge on essential oils focused on their antimicrobial properties, the assessment of their efficacy and safety as cosmetic preservatives.


2020 ◽  
Vol 38 ◽  
pp. 100785
Author(s):  
Sandhya Alice Varghese ◽  
Suchart Siengchin ◽  
Jyotishkumar Parameswaranpillai

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.


Author(s):  
Emine Arman Kandirmaz ◽  
◽  
Omer Bunyamin Zelzele ◽  

The use of edible biofilms in food packaging reduces the use of petrochemical polymers that are harmful to human health, such as PE, PP, PET. The second most common biopolymer in nature, chitosan is a nontoxic, nonantigenic, biocompatible and biodegradable polymer. Considering these features, it is frequently used in food packaging applications. Increasing needs for food amount and quality canalized food ındustry to fund in new packaging techniques that improve storage life and grade of foods. Active packaging systems, one of these methods, can be designed as a sensor, antimicrobial or antimigrant in order to extend the shelf life of the food product and to inform the shelf life in possible degradation. Essential oils, which are antimicrobial environmentally friendly packaging material additives, are used due to their effective biological activities. Essential oils that have known antimicrobial properties include lavender, rosemary, mint, eucalyptus and geranium. These oils are also edible. In this study, it is aimed to produce antimicrobial, ecofriendly, edible, printable biofilm for active packaging, using chitosan and peppermint essential oil. For this purpose, chitosan biofilms containing different rates (0, 1, 2.5, 5, 10%) of peppermint essential oil were produced by solvent casting method. Surface morphology were examined by SEM. The transparency of biofilms was determined by UV spectroscopy. Antimicrobial properties of the obtained films were determined against S. aureus and E. coli. Biofilms were printed with screen printing. The color, gloss, contact angle, surface tension values of all printed and unprinted samples were examined. As a result, chitosan biofilms which are loaded with peppermint essential oil were successfully produced. Biofilms are colorless, highly transparent and have good printability. It is concluded that the amount of peppermint essential oil increased inhibitory feature against S. aureus and E. coli. When the obtained results are examined, it is determined that the printable, ecofriendly, edible biofilms can be used in active food packaging applications.


2019 ◽  
Vol 8 (1) ◽  
pp. 3484
Author(s):  
Gopalakrishnaiah B. ◽  
Aniel Kumar O.

India is found to be a country with rich biodiversity and enormous treasure of herbal plants and consequently called as medicinal garden of the world. Plants are the richest source of natural antimicrobial agents. In recent years drug resistance to human pathogenic bacteria has been commonly reported from all over the world. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases; one approach is to screen local medicinal plants for possible antimicrobial properties. The present study was designed to evaluate the antimicrobial efficacy of hexane, chloroform and methanol crude extracts of the leaves of three important medicinal plants viz., Biophytum sensitivum (L.) DC, Bougainvillea spectabilis L. and Caesalpinia bonducella (L.) Fleming, collected from in and around Visakhapatnam District. The antimicrobial activity of the crude extracts was tested against three Gram Positive bacteria (Bacillus subtilis MTCC 441, Enterococcus faecalis MTCC 439, Staphylococcus aureus MTCC 737), Three Gram Negative bacteria (Escherichia coli MTCC 443, Proteus vulgaris MTCC 426 and Pseudomonas aeruginosa MTCC 1688) and three Fungal strains (Candida albicans MTCC 227, Epidermophyton floccosum MTCC 613 and Trichophyton mentagrophytes MTCC 7687) using agar well diffusion assay. Our results demonstrated that methanol extracts of these plants leaves have concentration dependent antibacterial activity against some of the tested organisms. Further studies should be undertaken to elucidate the exact mechanism of action of antimicrobial effect to identify the active ingredients which can be used for drug development program.


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