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In this paper, we investigate the effect of nano-CaCO3 on water absorption and tribological properties of polyamide-6. To this end, nanocomposites based on polyamide-6 blend, containing 1 to 5 phr of nano-CaCO3, and 1 phr of maleated polyamide (PA-g-MAH) as compatibilizer, are prepared via melt compounding followed by injection molding. The wear testing of each of the prototypes is carried out under identical conditions. Then, the morphology is studied using scanning electron microscopy. The addition of nano-CaCO3 particles with compatibilizer increases the wear resistance and reduces the water absorption. The results of experiments indicate that minimum wear rate is achieved by adding 1 phr of nano-CaCO3 with compatibilizer which is nearly 4 times less than pure PA6. Furthermore, the presence of nano-CaCO3 together with PA-g-MAH lowers the amount of water absorption as high as 32% wt in compare to pure PA6. In addition to these, this fact is also emerged that effect of compatibilizer is prominent on uniform distribution of the nano-CaCO3 particles among polyamide matrix that it leads to improve the tribological properties of the nanocomposite prototypes in the wear test.

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Listeria monocytogenes is a foodborne bacterial pathogen causing Listeriosis. The aim of this study was to evaluate the effect of methyl cellulose edible coatings containing Carum copticum L. essential oil and turmeric (Curcuma longa L.) extract to control the growth of L. monocytogenes inoculated in chicken portions storaged at 4°C. For this purpose, chicken meat samples were coated with different concentrations of 0.3, 0.45 and 0.65% of essential oil and concentrations of 0.25 and 0.5% of turmeric extract. In the control group, sterile distilled water was used instead of the solution. The samples were coated by dipping method. All specimens were then stored in the refrigerator and counted for L. monocytogenes on days 0, 4 and 8. In the present study, the minimum inhibitory concentration (MIC) of Carum copticum essential oil was 0.064%. The results of this study showed that there is a significant difference between L. monocytogenes population in coated and non-coated chicken samples (p<0.001). Statistical analysis showed that the mean log of the number of bacteria in all groups from day 1 to 8 showed a decreasing trend. In total, according to the results, it can be concluded that methyl cellulose coating containing Carum copticum EO with turmeric extract can be used to control the growth of L. monocytogenes in chicken meat.

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Escherichia coli O157: H7 is one of the most important pathogens causing food poisoning in meat products. In this study, the antimicrobial effects of Lavandula angustifolia and NaCl on growth control of Escherichia coli O157: H7 inoculated into minced beef during storage were investigated. minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Lavender essential oil for Escherichia coli O157: H7 were determined 0.625% and 1.25% by micro broth dilution method, respectively. Lavender essential oil was added to the minced meat in three concentrations (0, 0.5 and 1%) and NaCl in three concentrations (0, 2 and 4%). Subsequently, Escherichia coli O157: H7 was inoculated into minced meat at 10⁵ CFU/gr. Minced meat treatments with Escherichia coli O157: H7 were counted on days (0, 3, 6 and 9) kept at refrigerated temperature (4 °C). The results showed that growth control of Escherichia coli O157: H7 of all treatments was significant (P<0.05) and mean log CFU/gr of bacterial count in 9 days was lower in all groups than control. Comparatively, the effect of NaCl alone was greater than that of essential oil alone. The greatest inhibitory effect was related to the simultaneous use of essential oil and NaCl.
 

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Nowadays, the use of biodegradable packaging based on natural ingredients has attracted much interest from researchers. In this research different concentrations of persian gum (PG) (0, 0.25, 0.5, 0.75 and 1%) with different concentrations of carboxymethyl cellulose (CMC) (1 and 1.5%) were used to optimize biodegradable film production. For optimization of film production, maximum transparency value, contact angle, tensile strength, strain at break and minimum solubility, swelling and water vapor permeability were calculated. The results of the model showed that the effect of carboxymethyl cellulose and persian gum on all responses were significant (P <0.05) and increasing the percentage of carboxymethyl cellulose and persian gum increased solubility, swelling, tensile strength and contact angle and decreased moisture content, water vapor permeability permeability and transparency value. Based on the results of model prediction and comparison with experimental values, carboxymethyl cellulose at 1.5% and persian gum at 0.65% is the best result.
 

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Recently, the design and production of biodegradable films have received special attention than synthetic packaging due to the reduction of environmental pollution. The aim of this study was to investigate the effect of Persian gums (1%) and gellan gum (1%) on the physical, mechanical and morphological properties of composite films based on sodium caseinate (10%) as film reinforcing agents. The films were synthesized by solvent evaporation and the effect of each gum on the characteristics of the composite films was evaluated. The results showed that the addition of gums strengthened the composite films. So that the composite films showed mechanical resistance and good barrier properties versus moisture and light. The surface properties and morphology of the films also showed that the gums were well computability to the casein film and formed uniform and stiff films. In addition, composite films had acceptable transparency. Thus, it can be concluded that the use of composite films and the combination of different polysaccharides with protein matrices can improve the properties of the resulting films. On the other hand, by adding antimicrobial and antioxidant agents to biodegradable films, they can be considered as active packaging.

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The effect of chicken feet gelatin coatings and green walnut husk extracted on chemical, physical, microbial and sensory properties of rainbow trout fillet was investigated during storage period (12 days) at 5 °C. Chemical analyses (pH, TVB-N, TBA and FFA measurements), physical tests (moisture, color and texture measurements), microbial tests (TVC) and sensory evaluation were carried out periodically every four days. The results showed that by increasing the concentration of walnut green skin extract, the efficiency of the coating increased that the coatings containing 2.5 and 5% gelatin along with 1000 ppm of the extract improved the quality and shelf life of fish fillets compared to other ones. The values ​​of pH, TVB-N content, TBA and FFA in coated samples were significantly lower than the control sample (p<0.05). The coating treatment containing 1000 ppm of the extract also maintained the moisture, texture and color of the fillets and showed a lower microbial load than other treatments. From a sensory point of view, the treatments containing chicken foot gelatin and walnut green skin extract had the highest score at the end of the storage period compared to the control sample. Furthermore, the highest score was obtained for the samples coated by 1000 ppm walnut green skin extract.

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The aim of this study was to investigate the antimicrobial and antioxidant effects of chitosan edible film containing nanoemulsion of Melissa officinalis L. extract and Bunium persicum essential oil on Listeria monocytogenes inoculated into camel meat. The studied films were prepared using 2% chitosan and 2.5% and 5% of nanoemulsion of Bunium persicum essential oil and 4% of Melissa officinalis L. extract. The antimicrobial and antioxidant effects of coated camel meat during 16 days of storage at 4 °C with a 4-day interval (0, 4, 8, 12, 16) were evaluated. The coated portions were chemically evaluated. Most of the essential oil compounds include: cuminaldehyde (24.37%), γ-Terpinene (19.99%), and P-cymene (9.71%). The MIC of Melissa officinalis L. extract and Bunium persicum essential oil against L. monocytogenes were 1% and 0.25%, respectively. The antioxidant effects of films by DPPH method showed that the addition of essential oils and extracts increases the antioxidant properties of films. The antimicrobial effect of films by disk diffusion method, the largest diameter of growth inhibition zone (17.15 ± 0.16) was related to chitosan film containing 5% Bunium persicum essential oil and 4% Melissa officinalis L. extract. The average count of L. monocytogenes in the control treatment was higher than the other treatments. The results of TBARS showed that the antioxidant properties of films containing Bunium persicum essential oil and Melissa officinalis L. extract was higher than the control sample. The pH level in the samples coated with chitosan film containing 5% Bunium persicum essential oil and 4% Melissa officinalis L. extract was lower than the other treatments. In general, the prepared films have good antimicrobial and antioxidant properties against L. monocytogenes, which increase with the addition of plant compounds.

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In this study, the effect of bilayer edible coating of gelatin-chitosan containing nanoemulsion of Perovskia abrotanoides Kar. essential oil on growth control of Aeromonas hydrophila inoculated into rainbow trout fillets over a 12-day period at 4 °C was investigated. The chemical composition of the essential oil was evaluated by GC-MS, its antibacterial properties by disk diffusion, plate well and micro-dilution broth, and its antioxidant properties by DPPH.Treatments included control, gelatin, chitosan, gelatin+essential oil, chitosan+essential oil and gelatin-chitosan+essential oil. After preparation, the treatments were packed in sterile polyethylene bags in laboratory conditions and stored for 12 days at 4 °C and their microbial, chemical and sensorial properties were evaluated every 3 days. The results of GC-MS showed that eucalyptol (24.51%) and camphor (22.02%) are the main components. The MIC and MBC of Perovskia abrotanoides Kar. essential oil nanoemulsions were reported to be 0.0625 and 0.125%, respectively. The amount of TVB-N and POV increased during the study period. According to the results of POV and pH measurements, there was a significant difference between all treatments and control treatment (P<0.05). The mean reduction log of bacteria was significantly different between all treatments and the highest antibacterial effect was observed in the gelatin-chitosan coating containing nanoemulsion of Perovskia abrotanoides Kar. essential oil. According to the results, Perovskia abrotanoides Kar. essential oil has good antioxidant and antimicrobial properties and according to the test results, it was found that chitosan-gelatin coating containing nanoemulsion of  Perovskia abrotanoides Kar. essential oil has an effective antimicrobial effect against Aeromonas hydrophila and can protect sensory properties and increase shelf life of rainbow trout fillets as well as useful coating to increase the shelf life of food products.

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Microencapsulation is a common method to improve the viability of probiotic bacteria against environmental stresses. In this research, by using double emulsion with Persian gum, emulsion stability, physicochemical properties, microcoating efficiency and microcoating viability were investigated during storage and in a simulated gastrointestinal conditions of the digestive system. Encapsulation of Lactobacillus acidophilus in double emulsion (W/O/W) with Persian gum improved the survival under storage conditions at 4 °C for 28 days, and only 0.58 log decreased and free bacteria after passage 7 days reached zero. The microcoating efficiency was 88% and the emulsion stability was between 85% and 95.43%. The optical microscope image showed a distinct double emulsion. In the simulating conditions of the stomach, the number of bacteria decreased by 1.97 log for the micro-coated treatment and by 3.9 log for the treatment containing free bacteria, and in the simulating conditions of the intestine, it decreased by 0.45 log for the micro-coated treatment and for the treatment containing free bacteria. 1.3 decreased. The particle size was (525 nm), zeta potential (-44.68 mv) and dispersion index (0.33). The results showed that the use of Persian gum double emulsion improves the survival of Lactobacillus acidophilus against storage conditions and the simulated environment of the digestive system.