Neda Sallak; Abbasali Motallebi Moghanjoughi; Maryam Ataee; Seyed Amir Ali Anvar; Leila Golestan
Abstract
Nowadays it seems necessary to replace synthetic plastics with biodegradable films in food packaging due to their major threats to human health and the environment. In this study corn starch film composed of Ag-TiO₂ nanocomposites and Satureja khuzestanica essential oil (SEO) were ...
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Nowadays it seems necessary to replace synthetic plastics with biodegradable films in food packaging due to their major threats to human health and the environment. In this study corn starch film composed of Ag-TiO₂ nanocomposites and Satureja khuzestanica essential oil (SEO) were prepared and the antimicrobial, morphological, physical, and mechanical characteristics in chicken fillet packaging were assessed. The morphology of the films was investigated by scanning electron microscopy (SEM). The combination of energy-dispersive X-ray spectroscopy (EDX) with SEM analyzed the near-surface elements. The plain film showed higher WVP (2.82×10־⁷ g/m.h.Pa) than other films and the nano/essence film had the lowest moisture content% (21.6%). For determining the film's antimicrobial activity, chicken fillets were inoculated with Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus (separately with four prepared films). Microbial counting of the fillets was performed at three intervals (14 and 7th day) and the results showed a significant difference in reducing the number of microorganisms in nano/essence and essence films compared to the control group (chicken fillets packed in plastic bags) and plain film (at a rate of 1.5-2 log CFU/g). The rate of reduction of S. aureus was higher compared to S. Typhimurium and E. coli in the packing groups respectively. Sensory properties were also evaluated at three- intervals. The bio-polymer film incorporated with SEO and Ag-TiO₂ nanocomposites can be used for packaging foods and is able to delay microbial and physical spoilage in foodstuffs.
Seyed Amir Ali Anvar; Hamed Ahari; Nasim Mojarrad
Volume 3, Issue 1 , March 2020, , Pages 1-5
Abstract
Carvacrol was found in essential oils of thyme, oregano, wild bergamot, and some other plants. Although, a wide range of bioactivities such as anticancer, antioxidant, and antimicrobial has been identified for carvacrol, however, among all therapeutic properties it possesses a potent antimicrobial activity. ...
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Carvacrol was found in essential oils of thyme, oregano, wild bergamot, and some other plants. Although, a wide range of bioactivities such as anticancer, antioxidant, and antimicrobial has been identified for carvacrol, however, among all therapeutic properties it possesses a potent antimicrobial activity. The present study investigates the inhibitory effect of carvacrol as an active compound against the growth of Aspergillus flavus, besides its effect on the expression of aflatoxin-related (aflR) gene. Twelve fungal samples of A. flavus were used and the antimicrobial activity of carvacrol was tested against them using the minimum inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) according to the broth microdilution procedure. The expression of the aflatoxin regulatory (aflR) gene was examined by Reverse Transcriptase polymerase chain reaction (RT-PCR) technique. The results of MIC and MFC tests showed that carvacrol at 0.8 μg/ml and 3.5 μg/ml concentrations displayed antimicrobial activities on A. flavus, respectively. The RT-PCR result indicated that the expression level of aflR gene had decreased to 33% in the presence of carvacrol compared to 67% in the absence of the mentioned active compound. Together the results demonstrated that carvacrol not only exhibited antimicrobial activity against A. flavus but also reduced its gene expression level.
Mina Nasiri; Anousheh Sharifan; Hamed Ahari; Amir Ali Anvar; Shapour Kakoolaki
Volume 2, Issue 2 , November 2019, , Pages 26-31
Abstract
In recent years, there has been an increasing interest in the utilization of emulsion and food-grade nanoemulsions and their fabrication methods, and methods have evolved in the food industry and other fields. Emulsions, according to droplet diameter and stability, are divided into three important groups ...
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In recent years, there has been an increasing interest in the utilization of emulsion and food-grade nanoemulsions and their fabrication methods, and methods have evolved in the food industry and other fields. Emulsions, according to droplet diameter and stability, are divided into three important groups of conventional emulsions, nanoemulsions, and microemulsions; therefore, nanoemulsions are a class of emulsions. The small and fine size of the droplet in nanoemulsions (i.e. droplet diameter <100nm) make them applicable in some fields, due to their enhanced bioavailability, solubility, better stability against gravitational separation, appropriateness for delivery of lipophilic active agent’s components, high surface area per unit volume and antimicrobial property. Also, they need less surfactant in comparison with other constructions. There are many kinds of preparation methods that can be classified into low-intensity and high-intensity approaches. The basis of the high-intensity procedure is mechanical energy that comes from flows like cavitation, but the low-intensity procedure is based on physicochemical processes. The most notable ways in high-energy emulsification are high-pressure valve homogenization, microfluidization, ultrasonication, rotor-stator emulsification, and membrane emulsification. Low-energy emulsification is divided into thermal and isothermal methods for nanoemulsions fabrication. Thermal methods consist of phase inversion temperature (PIT) and isothermal methods consist of spontaneous emulsification (SE) and emulsion phase inversion (EPI). Also, today, there is a lot of evidence to compare the low-intensity approach with high-intensity one and some of them express that in the low-energy method, equipment is not expensive and special and this is a very important advantage in saving energy. Also, some researchers express that in the high-energy method, we need much less concentration of surfactant for the formation of small size droplet.
