Physical, mechanical and antibacterial properties of alginate film: Effect of the crosslinking degree and oregano essential oil concentration

2012 ◽  
Vol 110 (2) ◽  
pp. 232-239 ◽  
Author(s):  
Sergio Benavides ◽  
R. Villalobos-Carvajal ◽  
J.E. Reyes
Author(s):  
Anderson Javier Pazmiño Castro ◽  
Ana María Campuzano Vera ◽  
Karina Marisabel Marín Morocho

  Con la finalidad de reducir el número de personas afectadas por enfermedades transmitidas por alimentos,se elaboraron películas biodegradables activas con propiedades antibacterianas a partir de ácido poliláctico, polietilenglicol, y aceite esencial de orégano (Origanum vulgare) al 1% (p/p) y 2 % (p/p). Las películas biodegradables activas fueron elaboradas mediante el método de evaporación del solvente. Se evaluó la acción antibacteriana de las películas biodegradables activas mediante un ensayo de inhibición a la adhesión microbiana contra Salmonella spp. y Staphylococcus aureus. Se pudo establecer que los porcentajes de aceite esencial aplicados tienen poco efecto inhibitorio sobre Staphylococcus aureus, mientras que para Salmonella spp. hay un efecto directo sobre la inhibición, cuando la concentración de aceite esencial es del 2% (p/p). Para una concentración del 1% (p/p), el efecto inhibidor observado fue pobre. Los resultados indican que las bacterias Gram-negativas Salmonella spp son más susceptibles al daño en la pared celular provocado por el aceite esencial de orégano, debido al menor espesor de la misma. En contraste, el mayor grosor de la pared celular que presentan las bacterias Gram-positivas Staphylococcus aureus exige, en principio, de un tiempo mayor para poder producir la lisis celular. Las películas biodegradables activas con aceite esencial de orégano pueden emplearse para la conservación de los alimentos como una tecnología de barrera en conjunto con otros mecanismos de control microbiano y así minimizar tratamientos térmicos severos o reducir la utilización de aditivos alimentarios, que en concentraciones inadecuadas pueden producir cierta toxicidad.   Palabras clave: películas biodegradables activas, contaminación de alimentos, inhibición bacteriana.   Abstract In order to reduce the number of people affected by foodborne illnesses, active biodegradable films with antibacterial properties were made with polylactic acid, polyethylene glycol, and essential oil of oregano (Origanum vulgare) at 1% (w/w) and 2% (w/w). The active biodegradable films were made using solvent evaporation method. The active biodegradable films antibacterial action was evaluated by microbial adhesion inhibition test against Salmonella spp. and Staphylococcus aureus. It was established that the percentages of essential oil used have little inhibitory effect on Staphylococcus aureus, while for Salmonella spp. there is a direct effect on inhibition, when the essential oil concentration is 2% (w/w). For a concentration of 1% (w/w), the observed inhibitory effect was poor. The results indicate that Gram-negative bacterias Salmonella spp are more susceptible to cellular wall damage caused by oregano essential oil, due to its lower thickness. In contrast, the greater thickness of the cell wall that Staphylococcus aureus, Gram-positive bacteria has, requires, in principle, a longer time to produce cell lysis. Biodegradable active films with oregano essential oil can be used for food preservation as a barrier technology in conjunction with other microbial control mechanisms, thus minimizing severe heat treatments or reducing the use of food additives that, in inadequate concentrations can produce some toxicity.   Keywords: active biodegradable films, food pathogens, bacterial inhibition.


2000 ◽  
Vol 66 (4) ◽  
pp. 1646-1653 ◽  
Author(s):  
Panagiotis N. Skandamis ◽  
George-John E. Nychas

ABSTRACT Homemade eggplant salad, a traditional Greek appetizer, was inoculated with Escherichia coli O157:H7 NCTC 12900 supplemented with different concentrations of oregano essential oil (0.0, 0.7, 1.4, and 2.1% [vol/wt]) and stored at different temperatures (0, 5, 10, and 15°C). The product's pH was adjusted to 4.0, 4.5, or 5.0 with lemon juice. For each combination of the environmental factors, the bacterial counts were modeled, using the Baranyi model, as a function of time to estimate the kinetic parameters of the pathogen. A reduction of more than 1 log unit in E. coli O157:H7 counts was observed in all cases, and the death rate depended on the pH, the storage temperature, and the essential oil concentration. Separate quadratic models were developed with natural logarithms of the shoulder period and death rate as estimated by the growth model, as a function of temperature, pH, and oregano essential oil concentrations. These were further used to predict the population of E. coli O157:H7 NCTC 12900 from other inoculated eggplant salads at random conditions of temperature, pH, and oregano oil concentration. The predicted values were compared with viable-count measurements for validation.


2011 ◽  
Vol 74 (12) ◽  
pp. 2192-2198 ◽  
Author(s):  
AÍDA GÓMEZ-SÁNCHEZ ◽  
ENRIQUE PALOU ◽  
AURELIO LÓPEZ-MALO

The antifungal activity of Mexican oregano (Lippia berlandieri Schauer) essential oil by gaseous contact on the growth of Aspergillus flavus at selected essential oil concentrations (14.7, 29.4, 58.8, or 117.6 μl of essential oil per liter of air) and temperatures (25, 30, or 35°C) was evaluated in potato dextrose agar formulated at water activity of 0.98 and pH 4.0. Mold growth curves were adequately fitted (0.984 < R2 < 0.999) by the modified Gompertz model. The effect of the independent variables (concentration of essential oil and temperature) on the estimated model parameters (reciprocal of growth rate [1/νm] and lag time [λ]) were evaluated through polynomial equations. Both νm and λ were significantly (P < 0.05) affected by the independent variables; νm decreased and λ increased as essential oil concentration increased and temperature decreased, which suggests that Mexican oregano essential oil retards or inhibits mold germination stage. Further, minimum fungistatic and fungicide essential oil concentrations at 30 and 35°C were determined. Mexican oregano essential oil applied in gas phase exerts important antifungal activity on the growth of A. flavus, suggesting its potential to inhibit other food spoilage molds.


2020 ◽  
Vol 24 (105) ◽  
pp. 54-62
Author(s):  
César Mera Mendoza

Se ha analizado químicamente el aceite esencial de orégano cultivado en el cantón El Empalme en Ecuador para aplicarlo como agente bioconservador en alimentos. Para ello se empleó cromatografía de gases acoplada con espectrometría de masas. Se identificó como componente principal el carvacrol con 62,41%, seguido de β-cariofileno 8,84%, α-bergamoteno 6,75%, p-cimeno 6,24%, geraniol 4,29%; y α-humuleno, β-felandreno, 1-octen-3-ol, oxido de cariofileno, 4-terpineol, E-citral, γ-terpineno, z-citral en pequeñas cantidades. El Carvacrol le otorga al orégano múltiples propiedades antioxidantes, microbiológicas y conservantes de alimentos, además de potenciales aplicaciones en perfumería y cosmética. Palabras Clave: Orégano, aceite esencial, cromatografía de gases, espectrometría de masas. Referencias [1]J. Bruneton, Farmacognosia. Fitoquímica, Plantas Medicinales, Zaragoza: Acribia, 2001. [2]N. Rodríguez, « Uso de agentes antimicrobianos naturales en la consevacion de frutas y hortalizas,» Ra Ximhai, vol. VII, pp. 153-170, 2011. [3]S. Burt, «Essential oils: their antibacterial properties and potential applications in foods.,» Int J Food Microbiol, pp. 223-253, 2004. [4]J. Gutiérrez, G. Rodríguez, C. Barry-Ryan y P. Bourke, «Efficacy of plant essential oils against foodborne pathogens and spoilage bacteria associated whit ready-to-eat- vegetables: Antimicrobial and sensory screening.,» Journal of Food Protection, pp. 1846-1854, 2008. [5]R. Hulankova, G. Borilova y I. Steinhauserova, «Combined antimicrobial effect of oregano essential oil and caprylic acid in minced beef.,» Meat Science, pp. 190-194, 2013. [6]I. Fernández-Pan, M. Mendoza y J. Mate, «Whey protein isolate edible films essential oils incorporated to improve the microbial quality of poultry.,» Sci Food Agric, pp. 2986-2994, 2013. [7]L. Iturriaga, I. Olabarrieta y I. Maranon, «Antimicrobial assays of natural extracts and their inhibitory effect against Listeria innocua and fish spoilage bacteria, after incorporation into biopolymer edible films.,» Int J Food Microbiol, pp. 58-64, 2012. [8]C. Mera, V. Guerrón, S. Sánchez, J. Neira y R. Moreno, «Efecto del aceite esencial de orégano (Oreganum Vulgare L.) como agente antimicrobiano en la conservación de carne de dos especies de tilapia.,» Nutrición Clínica, Dietética y Hospitalaria, nº 39, pp. 35-36, 2019. [9]J. Soriano, Micotoxinas en alimentos, Ediciones Díaz de Santos: Madrid, 2007. [10]M. Pascual, K. Slowing, E. Carretero, M. Sánchez y A. Villar, « Lippia: Traditional uses, chemistry and pharmacology.,» Ethnopharmacol, pp. 201-214, 2001. [11]H. Peredo, E. Palou y A. López, «Aceites esenciales: métodos de extracción,» Temas selectos de ingeniería de alimentos, vol. 1, nº 3, pp. 24-32, 2009. [12]A. Kimbaris y N. D. D. Siatis, «Comparison of distillation and ultrasound - assisted extraction methods for the isolation of sensitive aroma compounds from garlic,» Ultrasonics Sonochemistry, vol. 13, pp. 54-60, 2006. [13]B. Bayramoglu, S. Shamin y G. Sumnu, «Solvent-free microwave extraction of essential oil from oregano,» Journal of food engineering, nº 88, pp. 535-540, 2008. [14]M. Golmakani y K. Rezaei, «Comparison of microwave-assisted hydrodistillation with the traditional hydrodistillation method in the extraction of essential oil from Thymus Vulgarus,» Food Chemistry, nº 101, pp. 1558-1564, 2008. [15]M. Ortuño, Manual práctico de aceites esenciales, aromas y perfumes, España: Aiyana, 2006. [16]A. Caldas, «Optimización, Escalamiento y Diseño de una Planta Piloto de Extracción Sólido Líquido,» Universidad de Cuenca , Cuenca, 2012. [17]M. Méndez, K. Bodero y S. Alvarado, «Biosíntesis de nanopartículas de hierro (FE3O4) en la remidacion de aguas contaminadas,» Universidad, Ciencia y Tecnología, vol. 24, nº 96, pp. 35-45, 2020. [18]J. Sercik, «Detector in gas chromatography,» Journal of Chromatography Library, vol. 4, pp. 34-42, 1975. [19]E. Gimeno, «Compuestos fenólicos. Un análisis de sus beneficios para la salud,» Offarm, vol. 23, nº 6, pp. 80-84, 2004. [20]J. Bello, Ciencia bromatológica: principios generales de los alimentos, Madrid: Díaz de Santos, 2000. [21]R. Fonnegra y S. Jiménez, «Plantas medicinales aprobadas en Colombia,» Universidad de Antioquia, Medellín, 2007. [22]N. Davies, «Gas chromatographoic retention indices of monoterpenes and sesquiterpenes on methyl silicone and carbowax 20 M. phases.,» Journal of Chromatography A, pp. 1-24, 1990.


2020 ◽  
Vol 12 (7) ◽  
pp. 864-869
Author(s):  
Juliana Reghine Souza ◽  
Kely Silveira Bonfim ◽  
Marcos Vinicius Lorevice ◽  
Daniel Souza Correa ◽  
Luiz Henrique Capparelli Mattoso ◽  
...  

This work describes an outstanding synthesis of poly(ε-caprolactone) nanoparticles of distinct sizes loaded (PCLNP/OEO) or not (PCLNP) with oregano (Origanum vulgare) essential oil (OEO) by the nanoprecipitation method in order investigate the antimicrobial properties against bacteria Escherichia coli and Staphylococcus aureus. OEO antimicrobial activity was achieved by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). FTIR spectra indicated that encapsulation of OEO by PCLNPs was successful. Scanning electron microscopy images revealed that PCLNP and PCLNP/OEO presented spherical shape with diameters around 150 nm, while PCLNP exhibited size distribution raging 158 to 300 nm and zeta potential ranging from -13.8 to -28.5 mV. Thermogravimetric analysis indicated an increase in initial temperature of weight loss for PCLNP/OEO. PCLNP with 80% wt. of OEO has exhibited the highest decrease of growth of bacteria, and MIC against S. aureus and E. coli and MBC only for E. coli, which indicate a promising alternative for designing stable antimicrobial nanoparticles for application in novel food active packaging.


2019 ◽  
Vol 25 (16) ◽  
pp. 1809-1816 ◽  
Author(s):  
Armenuhi Moghrovyan ◽  
Naira Sahakyan ◽  
Anush Babayan ◽  
Naira Chichoyan ◽  
Margarit Petrosyan ◽  
...  

Background: Origanum vulgare is used in Armenian cuisine as well as in folk medicine. The aim of this investigation was to determine the peculiarities of the chemical composition of Armenian flora’s oregano essential oil (EO) and ethanol extract (EE) and to characterize mainly antioxidant and antibacterial properties in vitro. Methods: EO of plant aerial parts was extracted by the hydro-distillation method, and the composition was analyzed by gas-chromatography (GC). EE was prepared using ethanol as a solvent. Antioxidant, antibacterial and other biological activity of EO and EE was determined using appropriate methods. Results: The terpenes were found to be the greatest part of oregano EO (β-caryophyllene epoxide - 13.3 %; β- caryophyllene -8.2 %; ο-cymene - 5.2 %). The flavonoid content of EE was 3.9±0.7 mg g-1 catechin equivalents. Antiradical activities of EO and EE expressed with half-maximum inhibitory concentrations were 1057 µg mL-1 and 19.97 µg mL-1. The antioxidant index in the case of using extract (1000 µg mL-1) was 77.3±1.5 %. The metal chelating activity of EE was 74.5±0.2 %. The tyrosinase inhibitory activities of EO, EE and arbutin were 26.5±0.3 %, 6.5±0.2 % and 50±0.1 %, respectively. Both EO and EE of oregano were able to suppress the growth of testmicroorganisms including clinical pathogen isolates, but have moderate antimicrobial activity. EO antibacterial activity against ampicillin-resistant Escherichia coli was similar to the activity against non-resistant strain. EE was not active against ampicillin-resistant E. coli in contrast to non-resistant one. Conclusion: The results indicate high antioxidant and moderate antibacterial as well as high antiradical, metal chelating, tyrosinase inhibitory activity of oregano EO and EE, which can be used as a natural source of terpenes, flavonoids and other phytochemicals in medicine, pharmaceutics, cosmetics and food industry. EO has antibacterial activity also against ampicillin-resistant E. coli.


Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2923
Author(s):  
Fotini Plati ◽  
Rigini Papi ◽  
Adamantini Paraskevopoulou

Oregano essential oil (OEO), due to its wide variety of biological activities, could be a “green” alternative to chemical preservatives. On the other hand, the difficulties in its use or storage have turned researchers’ interest in encapsulation strategies as a way to face stability and handling issues. Fabrication of OEO-loaded particles, using nano spray drying technique (NSD) and whey protein isolate-maltodextrin mixtures (1:1, 1:3) as wall materials appears to be a novel and promising strategy. The obtained particles were characterized in terms of volatile composition, encapsulation efficiency, and physicochemical, molecular, morphological, and antibacterial properties. The results confirmed that encapsulation of OEO using NSD achieved high levels of powder recovery (>77%) and encapsulation efficiency (>98%) while assisting in the retention of the main bioactive compounds. The partial replacement of WPI by MD significantly affected particles’ physical properties. FTIR analyses revealed the possible structural stabilization of core and wall materials, while SEM verified the very fine size and spherical shape. Finally, antibacterial studies demonstrated their activity against Escherichia coli and Staphylococcus aureus, which is much stronger in comparison with that of pure OEO, proving the positive effect of NSD and particles’ potential in future food applications.


Author(s):  
Azadeh Foroughi ◽  
Pouya Pournaghi ◽  
Fariba Najafi ◽  
Akram Zangeneh ◽  
Mohammad Mahdi Zangeneh ◽  
...  

Medicinal plants are considered modern resources for producing agents that could act as alternatives to antibiotics in demeanor of antibiotic-resistant bacteria. The aim of the study was to evaluate the chemical composition and antibacterial activities of essential oil of Foeniculum vulgare (FV) against Pseudomonas aeruginosa and Bacillus subtilis. Gas chromatography mass spectrometry was done to specify chemical composion. As a screen test to detect antibacterial properties of the essential oil, agar disk and agar well diffusion methods were employed. Macrobroth tube test was performed to determinate MIC. The results indicated that the most substance found in FV essential oil was Trans-anethole (47.41 %), also the essential oil of FV with 0.007 g/ml concentration has prevented P. aeruginosa and with 0.002 g/ml concentration has prevented B. subtilis from the growth. Thus, the research represents the antibacterial effects of the medical herb on test P. aeruginosa and B. subtilis. We believe that the article provide support to the antibacterial properties of the essential oil. The results indicate the fact that the essential oil from the plant can be useful as medicinal or preservatives composition.


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