جستجوی مقالات مرتبط با کلیدواژه « zinc oxide » در نشریات گروه « کشاورزی »

In this study, the effect of nanoparticles on oxide at three levels of 1, 3 and 5% was added to polylactic acid and chitosan nanocomposites and the results of its SEM (electron microscope) evaluation were evaluated and showed films containing polylactic acid and chitosan. It had an irregular and compact structure and with the addition of nanoparticles on oxide, it had a regular and cohesive structure. And water vapor permeability showed a significant effect (P <0.05). The results of histometry showed that with increasing the concentration of nanoparticles, the tensile strength of the film and the nanocomposite coating was significantly lower than the control treatment (P <0.05). Also, large changes in length to break point did not show a statistically significant difference. The results of tissue stiffness of this study also showed that during the 15-day storage time, the test treatment had the highest amount of stiffness. The effect of film and coating of nanocomposites based on polylactic acid and chitosan containing nanoparticles on zinc oxide on microbial properties indicated that during the shelf life of bread containing polylactic acid and chitosan dimers has an inhibitory effect on fungal growth by increasing nanoparticles on zinc oxide. Increases significantly. It also showed that the shelf life of seven sliced ​​toast containing the mentioned variables was higher at 5% level compared to the control treatment.

In food industries, nanotechnology can potentially provide solutions to food packaging with short shelf life. Nowadays, there has been an increasing interest in nanocomposites for many advantages in food packaging. Polymers have a wide range of applications in food packaging, and many studies have been conducted on the simultaneous use of nanoparticles and polymers in food packaging, which can be attributed to the synergistic effect of these nanoparticles. One of the most important goals is to increase the safety and quality of food during storage, transportation and protection against adverse factors such as chemical, moisture, light and external forces. The aim of this study was to investigate the effect of film prepared from PET containing nanoparticles of ZnO, TiO2 and TiO2 + ZnO nanoparticles in quantities 0.25, 2 and 2.25%. Weight is based on the physicochemical properties of mayonnaise.

The PET-based nanocomposites containing 2% by weight of TiO2 nanoparticles and 0.25% by weight of ZnO nanoparticles were prepared by melt mixing using an extruder. Mixtures of PET nanoparticles were dried in the oven at 170 ° C before loading in the extruder and fed simultaneously from the feeder to the extruder. The material was melted and thoroughly mixed as it passed through the extruder. The melt from the extruder was cooled by passing through a pool of cold water and entered the granule mill to make granules. Pure PET samples were molded as control and PET-based preforms containing nanoparticles. At the end of the molding stage, chillers were used to cool the preforms. PET-based bottles containing nanoparticles were produced by blowing preforms at appropriate temperatures and pressures for 120 to 140 seconds. The morphology and particle size of the bottle layers were investigated using FE-SEM. Then physicochemical properties including colorimetry, pH and acidity of mayonnaise, oxidative and peroxide stability, acidity of the extracted oil and migration of Zn +2 and Ti +2 ions from mayonnaise during 90 days at room temperature (22 ± 2 ° C) Celsius) was examined.

Based on FE-SEM images, the films of polymer bottles containing ZnO and TiO2 nanoparticles showed a smoother surface than the films of polymer bottles of ZnO + TiO2 nanoparticles. Moreover, the results of physicochemical properties showed that the reduction of brightness index as well as pH, acidity number, peroxide number and oxidative stability of mayonnaise sample during 90 days of storage in a bottle containing nanoparticles had a significant decrease compared to the control sample. According to the results of the present study, mayonnaise shelf life indices can be increased.

Due to the importance of food emulsions such as mayonnaise, it is necessary to pay attention to the quality characteristics and shelf life of this popular condiment. The use of these nanocomposites could be a promising approach to creating new active packaging in the food industry.

 Given the energy crisis in the world, increasing environmental pollution, clean, renewable energy and the reduction of environmental pollution are needed. Soil is the main source of agricultural production. Therefore, maintaining soil health and fertility is very important for sustainable food production. Nanotechnology is a good way to reduce soil issues in agriculture, a promising method to improve soil properties and significant capacity to increase yield. Nanotechnology is one of the newest technologies that is used in all fields of science and research due to its high potential and unique features, including natural resources and soil protection. Nanoparticles have the ability to change some physical, mechanical and chemical properties of soil due to their very high specific surface area and activity. Nanoparticles increase the cation exchange capacity of soil and soil porosity. Among all nanoparticles, zinc oxide (ZnO) is one of the most widely used nanoparticles. Zinc oxide nanoparticles due to their high specific surface area can act as a bonding agent between particles and stabilize the soil structure by flocculating soil particles. Although many studies have used zinc oxide nanoparticles (ZnO) in the field of heavy metal contamination in soil, aqueous solutions and plants, the effect of one nanoparticle on soils with different textures has been less reported. Therefore, objective of this study was to investigate the effect of zinc oxide nanoparticles on some physical and chemical properties of soils with different textures.
 In this study, three soil samples with different textures, including sandy loam, loam and clay were collected from three locations as Malayer, Abbasabad and Nahavand, in Hamedan province, respectively. Samples were taken from soil surface (0-20 cm depth). The soil samples were transferred to the Soil Physics Laboratory. After  air drying, they were passed through a 4 mm sieve and mixed with specific weight percentages of zinc oxide (ZnO) nanoparticles (zero, 0.5, 1 and 3 % W/W) in three replications. After preparing the treated samples, the soils were homogeneously poured into plastic containers measuring 18 × 5.5 × 18 cm with a specific bulk density related to the field. The treated soils in plastic containers, were wetted and dried with municipal water for 120 consecutive incubation period. After 120 days from the start of incubation, the samples were taken from the containers. Some physical and chemical properties including pH, cation exchange capacity, organic matter, calcium carbonate and electrical conductivity were measured.
 The results showed that the use of nanoparticles increased the cation exchange capacity in two textures of loamy and clay soils. The increment was significant compared to the control in loamy soil at two levels of 1 and 3% and in clay soil in all three levels of 0.5, 1 and 3%. Electrical conductivity increased and decreased (P <0.05) at 3% level for loamy soil and at 3% for sandy loam and clay soils, respectively. In contrast, the application of nanoparticles led to a decrease in pH and organic matter content (P <0.05) in sandy loam and clay soils, respectively. At the level of zero and 0.5%, the order of pH was: sandy loam> clay> loamy soil, with significant differences. But at the level of 1%, the order of pH was: sandy loamy> loamy> clay, with significant differences. At 3% level, the order of pH was: loamy> sandy loam> clay, with significant differences. At all levels of zero, 0.5, 1 and 3% of zinc oxide nanoparticles, the amount of organic matter was significantly in loamy> clay> sandy loam. Application of different levels of zinc oxide nanoparticles in clay soil reduced the percentage of calcium carbonate (P <0.05) (at the 3% by weight level), but had no effect on the amount of this variable in sandy loam and loamy soils. At all levels of zero, 0.5, 1 and 3%, the amount of soil calcium carbonate was significantly in the following order: clay> sandy loam> loam.
 According to the results obtained in this study, it can be concluded that the use of nanoparticles can be a good solution to reduce the harmful environmental effects of chemical fertilizers. In addition to the positive effect of zinc oxide nanoparticles on physical and chemical parameters in different textures, the selection of the most optimal level of zinc oxide nanoparticles should be economically applicable. This requires further studies to determine the significant effects of nanoparticles on the physicochemical properties of the soils in different conditions to determine the optimal amount of nanoparticles, in order to save costs.

Strawberry (Fragaria x ananassa) as one of the most widely consumed fruits in the world is produced in 73 countries worldwide (Muzzaffar et al., 2016). Strawberry is mainly grown in Kordestan, Golestan, Mazandaran and Gilan provinces of Iran with Kordestan, Paros, Queen Eliza, Selva, Camarosa and Pajero as the most important cultivars. Since strawberry is very perishable fruit, requires careful harvesting and handling to maintain its quality after harvesting. Considering its sensitivity to physical injuries and fungal invasion besides rapid softening and susceptibility to rots, strawberry fruit has a short postharvest life. Gray mold, caused by Botrytis cinerea is considered as the most important strawberry disease with many negative impacts on ripening, marketing and postharvest life of the fruit (Abd-Alla et al., 2011). No strawberry cultivar is resistant to gray mold. The pathogen is able to infect stored strawberries because mycelia spread from infected fruit to adjacent healthy fruit. Several technologies have been used to reduce postharvest losses and extend the storage life of strawberries. These technologies include chemical control, low temperature storage, control atmosphere packaging, essential oils and irradiation (Marjanlo et al., 2009; Maraei and Elsawy 2017). Most of these techniques could be effective for shelf life extension of strawberry fruit. However, many reports documented harmful effects of chemical fungicides on human health and environment besides causing fungi resistance. Some compounds and methods may also have adverse effect on color, flavor or texture of the fruit. Thus, in the past few decades, research has focused on the use of safe and natural preservatives. It was reported that the storage life of strawberry fruit increased by application of cumin essential oil (Marjanlo et al., 2009). Among the various alternatives, metal oxides such as magnesium oxide and zinc oxide are catching the attention of scientists worldwide. These oxides render antimicrobial activity with higher stability in comparison to organic antimicrobials. Zinc oxide nanoparticles are less toxic than other nanoparticles such as silver nanoparticles. In addition, they are safer for human beings in comparison to other metal oxides (Al-Naamani et al., 2018). Al-Naamani et al. (2018) proved the efficiency of chitosan-znic oxide nanocomposite coatings in extending the shelf life of the packed okra. The application of nanocomposite film containing 2% zinc oxide nanoparticles maintained the qualitative characteristics of Mazafati date during cold storage (Sadeghipour et al., 2019). The aim of this study was to investigate the effect of different concentrations of zinc oxide solution on quality and shelf life of strawberry fruits (camarosa cultivar) during ambient and cold storage.

Zinc oxide solution with brand name Eimen Jav was purchased from Eimen Novin Pushan Pak Company. “Camarosa” strawberries at commercial maturity stage were harvested from a greenhouse located in Hashtgerd, Alborz province, Iran and then transported to Agricultural Engineering Research Institute. Fruits of uniform size without any defect were selected and used for the experiments. Strawberries were dipped in the solution at different concentrations (0.31%, 0.63%, 0.94%, 1.25%) for 1, 2 and 3 minutes. Then, the fruits were air dried at room temperature, put in plastic fruit boxes and stored at ambient temperature (25 oC, 30% RH) for 6 days and cold room (4 oC, 85-90% RH) for 21 days. The sampling was done on day 0, 2, 4, and 6 through ambient temperature and on day 0, 7, 14, and 21 through cold storage. Decay percent was calculated by visual observation of each sample. Fruits with visible brown spot and softened area were regarded as decayed fruit. Texture evaluation was performed by a texturometer. Firmness values of each individual strawberry were measured at two points of the equatorial regions using a 5 mm diameter probe and 500 load cell, at 2 mm/sec-1. Total soluble solids content was measured using a refractometer, Titratable acidity (TA) was calculated by titrating of clear juice of strawberry against 0.1 N NaOH solution and the results were expressed as citric acid %. Ascorbic acid content was determined by using 2,6-dichlorophenol indophenols titration method. A five-point hedonic scale was used for conducting the sensory evaluation of the samples. A panel of 15 judges was selected to evaluate the treatments for various sensorial parameters like appearance, texture, taste, and overall acceptability. Plain water was given to the judges to rinse their mouth between the evaluations of samples. The study was conducted as a factorial experiment in randomized complete design. All determinations were carried out in triplicates and the means were separated by Duncan Multiple Range test. All statistical tests were done by SPSS ver. 22 and were meaningful at 5%.

Ascorbic acid content was significantly affected by zinc oxide solution at different concentrations and immersion times. The ascorbic acid value of the control was significantly lower than the treated fruits. Ascorbic acid content decreased through the storage time as observed in all treatments and the control. Zinc oxide treated strawberries at 0.31% concentration for 3 minutes had higher firmness values and better qualitative characteristic with increased shelf life up to 2 weeks during cold storage. Additionally, this treatment reduced fungal decay up to 50% compared to the control during cold storage. Zinc oxide solution at 0.63% concentration for 3 minutes increased the shelf life of strawberry fruits up to 48 hours under ambient temperature. In this condition, fungal decay reduced up to 70% as compared to the control. Zinc oxide solution had no effect on sensory attributes of the fruits.

This study showed that strawberry fruits treated with zinc oxide solution (Eimen Jav solution) at recommended concentration and under storage in cold room had better quality and less decay than the control. The results introduce zinc oxide solution as a useful method for maintaining strawberry quality and extending its storage life.

Introducing an effective antibacterial agent is very important in controlling pathogenic and antibiotic-resistant bacterial strains. Recent advances in nanotechnology, especially the ability to fabricate biological nanoparticles, have led to the development of a wide range of antimicrobial agents. Therefore, the aim of this study is to investigate the antibacterial properties of ZnO nanoparticles (NPs) in inhibiting resistant strains of Acinetobacter baumannii. Ten samples of Acinetobacter were collected from clinical centers of Khorramabad city in 2020 and were identified based on biochemical tests. After treatment of MDR strains with sub-minimum inhibitory concentration (MIC) of ZnO NPs, the expression level of efflux pump genes (AdeA, AdeC) was evaluated using real-time PCR. After applying the effect of ZnO NPs on AdeA gene, 80% of the samples showed reduced expression. 20% of the sample also had incremental expression. Also in AdeC gene, 40% of the samples showed reduced expression after the effect of ZnO NPs. 60% of the samples also had incremental expression. According to the results, the optimal inhibitory effect of biosynthesized ZnO NPs on the expression of AdeA and AdC genes, which play an important role in drug resistance of the Acinetobacter species, was evident. On the other hand, due to the increased expression in 60% of the samples for the AdeC gene, the possibility of mutations in the regulatory genes was raised. It seems that ZnO NPs can be used as a pharmaceutical candidate in the pharmaceutical industry in the future.

The aim of this study was to investigate the effect of physical properties of zinc oxide on serum changes of interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα) and occludance 1 (ZO-1) in broiler breeders. A total of 200 hens (Ross 308), at the age of 54 weeks, was used in a completely randomized design with 4 treatments, 5 replications, and 10 birds per replication. In this study, two levels of zinc (70 and 100 mg/kg diet), and two ZnO sources (regular zinc oxide and activated zinc oxide) were used. The production performance of the birds and the concentration of interleukin 6, tumor necrosis factor and occludin in serum were measured at the end of the experiment. The supply of 70 mg/kg diet in both its regular and activated ZnO forms increased blood concentration of TNFα and ZO-1 (P<0.01). In contrast, addition of 100 mg of ZnO from both sources reduced pro-inflammatory factors and concentration of ZO-1 in the blood (P<0.01). Results of present study showed that the concentration of blood inflammatory factors and tight junction proteins in hens that are prone to intestinal inflammation which probably occur due to a meal in a day decreases with the consumption of higher levels of zinc. Changes in inflammatory factors and the concentration of tight junction proteins were in the same direction. Consumption of 100 mg of activated ZnO decreased IL-6 compared to 70 mg (P<0.01). Therefore, it is concluded that the change in physical properties, has improved the functionality of ZnO.

Owning to drawbacks of synthetic polymers, biodegradable packaging materials (biopolymers) have received more attention both in studies and industrial applications. However, compared to conventional packaging, the biodegradable materials have some limitation must be eliminated either by using composite preparation method or introduction of nanotechnology. Inclusion of metal nanoparticles and their oxides are of the new approaches to improve the properties of packaging films. Therefore, the present study attempted to investigate the effect of ZnO (0, 2.5 and 5%) and β-glucan (0, 10 and 20%) incorporation on chemical and microbial properties of gelatin based biodegradable film over storage of chicken fillet. Results showed that incorporation the both of ZnO and β-glucan have significantly (p<0.01) improved the barrier properties against both of moisture absorption and water vapor permeability and the best properties obtained with film containing 5% of ZnO and 20% β-glucan. In addition, based on microbial tests result, it was obvious that the ZnO loaded films have antimicrobial properties and the highest inhibition activity obtained with 5% of ZnO against the all of studied pathogenic bacteria. Accordingly, the film containing 5% ZnO and 20% β-glucan is introduced as the most effective film for packaging of chicken fillets.

In this research the effects of different levels and particle sizes of zinc oxide on reproductive performance of hens and roosters of broiler breeders were evaluated. A total of 200 female Ross 308 broiler breeders in a completely randomized design with 4 treatments, 5 replicates and 5 birds per each replication, and 24 male Ross 308 broiler breeders in a completely randomized design with 4 treatments, 6 replicates and one bird per each replication at 54 weeks of age were used. The experimental treatments included the diets containing 70 mg zinc from zinc oxide with large particle size (LPZnO-70), 100 mg zinc from zinc oxide with large particle size (LPZnO-100), 70 mg zinc from zinc oxide with small particle size (SPZnO-70) and 100 mg zinc from zinc oxide with small particle size (SPZnO-100). The results indicated that the experimental treatments had no significant effect on egg production, body weight, egg weight and egg yolk weight. In the entire experimental period, the egg shell thickness was significantly higher in treatment containing SPZnO than LPZnO (P<0.001). The highest and lowest fertility and hatchability ratioes were observed in treatments containing SPZnO-100and LPZnO-70, respectively. The highest semen volume was observed in roosters of treatments containing SPZnO-100 and LPZnO-100 (P< 0.05). Generally, it can be concluded that SPZnO has a more desirable effect on reproductive parameters of broiler breeders due to its higher bioavailability. Since the level of 100 mg zinc per kg of diet from both sources of zinc oxide resulted in better reproductive performance, the utilization of SPZnO-100 might be recommended.

The cyst nematode is one of the major pathogens of sugar beet, which, many studies has been done for its effective control. The most of existing control methods of cyst nematode are troublesome. Recently, the use of nanoparticles in various aspects of human life, the application of nanotechnology in agriculture and especially in the plant protection has also been considered. However, a detailed study on the effect of zinc and silver nanoparticles on cyst nematode has not been done. In order to examine the possibility of nematode control, the effect of zinc and silver nanoparticles on different life stages of sugar beet cyst nematode (H. schachtii) in vitro and the effect of the nanoparticles on the nematode pathogenicity and damages were assessed under greenhouse conditions. The results of laboratory tests showed increased mortality of larvae, and reduced egg hatching, due to the use of silver and zinc oxide nanoparticles. Mean comparisons of nanoparticles were revealed the more effective of nano silver on the inhibition of the hatching egg and larvae mortality. Results of the effect of nanoparticles on nematode pathogenicity under greenhouse conditions revealed that the nanoparticles reduce the cyst nematode damages. The results showed that silver Nano Silver at a concentration of 100 mg/l mixed with soil were more effective than other treatments. According to the results, probably the toxicity of nanoparticles had been more effective to control of cyst nematode in 100 mg/l nanoparticles in soil mixed method.

Metal oxide nanoparticles have unique physical and chemical properties. These components have shown antimicrobial effects against a wide range of microorganisms. In order to improve the physical properties of metal oxide nanoparticles, doping other elements with metal oxide nanoparticles is an effective way. Bacillus cereus is a gram-positive bacteria causing food-borne diseases. In this study, the antimicrobial effects of doped zinc oxide nanoparticles with manganese or iron on Bacillus cereus have been studied. To investigate the synergistic effects of the combined nanoparticles with two common biocides, including hydrogen peroxide and sodium hypochlorite, have been used. Co- precipitation method was used to prepare nanoparticles of manganese-zinc oxide and iron-zinc oxide. In this method, zinc sulfate and manganese sulfate were used to prepare manganese-zinc oxide  and iron sulfate and zinc sulfate are used for Zn- Fe doped nanoparticles. After preparing the sulfate solutions, the sulfate solutions were mixed and placed in an ultrasonic apparatus at a frequency of 57 kHz for 2 hours at 50ºC. Then, it was stirred at 80°C. A solution of NaOH was added until the pH of the solution reached 12. In these conditions, the mixing was done for 30 minutes. The solution was placed at ambient temperature for 18 hours. Then the centrifuge was performed to separate the sediment. Purification was done through washing with distilled water and ethanol. The precipitates were dried in the vacuum oven. In this way, the doped nanoparticles of manganese-zinc oxide and iron-zinc oxide were obtained. The Fourier transform infrared spectrum (FTIR) was carried out by the Perkin-Elmer apparatus of the Spectroma2 model, using a dry potassium bromide tablet at a frequency range of 4500-4000 cm-1. The X-ray diffraction was tested using the Phillips PW1820 from 2º to 80º. Structure of produced nanoparticles was assessed by the HITACHI electron microscope, the H-7500 model, by placing a drop of nanoparticles dissolved in methanol on a special lining with carbon coating and air drying, and performing microscopic images using an electron microscope in 100kv. The bacteria used in this study included Bacillus cereus (PTCC 1665) was purchased from the Iranian Scientific and Industrial Research Center and was transferred to the BHI medium in sterile condition and incubated for 32 hours at a temperature of 32°C. Microbial cells were isolated by centrifugation at 4000 rpm. McFarland's method was used for determining the bacterial population. Dilution was carried out to reach a population of about 106 CFU/ml. Agar disc diffusion method was used for assessing the antimicrobial effect of the doped nanoparticles alone or in combination with tested biocides (hydrogen peroxide, sodium hypochlorite). At first, 106 CFU/ml of Bacillus cereus were inoculated on the surface of Blood Agar. Then, 5, 10, 20, 30, 50, 100 and 200 mg/L of each of the nanoparticles were placed on the surface of the culture medium and then the plates was incubated at 37°C for 24 hours. Inhibition zone was considered as antibacterial activity. In order to investigate synergistic effects, inhibitory fraction index test was calculated. All experiments were performed in three replications. Statistical analyzes were performed using STATISTICA software. Results obtained from X-ray and FTIR analysis of doped nanoparticles confirmed that co- precipitation is a suitable method for producing doped nanoparticles of zinc oxide. TEM analysis of produced nanoparticles also affirm formation of doped nanoparticles of zinc oxide with manganese and iron. The results of antimicrobial tests showed that Mn-Zn oxide nanoparticles have more antimicrobial effects on Bacillus cereus than zinc oxide (32mm inhibition zone) whereas Fe- Zn oxide nanoparticles cause inhibition zone about 12 mm. In addition, both doped nanoparticles have more antimicrobial effects than zinc oxide nanoparticles alone, resulted in doping process improves antimicrobial properties of zinc oxide. The synergistic effects of synthetic nanoparticles in the combination of two common antimicrobial agents, including hydrogen peroxide and sodium hypochlorite, have been identified. Both nanoparticles show synergistic effects in combination with two tested biocides (especially in high concentrations). A mixture of two biocides with nanoparticles increases their antimicrobial properties. Manganese-zinc oxide nanoparticles with hydrogen peroxide and sodium hypochlorite showed a partial synergistic effect at low concentrations (5 + 20) and a complete synergistic effect at higher concentrations. In the case of iron-zinc oxide, combination of this nanoparticle with hydrogen peroxide and sodium hypochlorite, has complete synergistic effects at high concentration (100 + 200) and at other conditions, shows partial synergistic effects.

In this research, polypyrrole (PPy) and polypyrrole-zinc oxide (PPy-ZnO) nanocomposites were synthesized by chemical method on the bacterial cellulose film in the presence of Iron chloride ΙΙΙ. The size, shape and morphology of the synthesized particles were studied using scanning electron microscopy. The results showed that the polypyrrole particles (60-150 nm) are spherical in shape, while the nanoparticles of polypyrrole-Zinc oxide are granular in shape and are in the range of 30-120 nm. Mechanical properties including, strain to break and tensile strength and antimicrobial-antifungal properties, as well as antioxidant properties and electrical conductivity of the films were studied. The results showed that the addition of polypyrrole decreased the electrical resistance, resulting in an increase in the electrical current of the film. The addition of nanoparticles reduced the mechanical properties and decreased the tensile strength. The inhibitory power of free radicals of the film increased with the addition of zinc oxide. The synthesis and increase of the polypyrrole synthesis time on a cellulose film had a positive effect on the antimicrobial and antifungal properties of films, but zinc oxide nanoparticles were more effective on antifungal properties.

Date fruit (Phoenix dactylifera L.) is a rich source of sugar, fiber, some vitamins, minerals and antioxidant phenolic compounds. The physico-chemical, biochemical and microbial changes occurring in this fruit reduce its quality properties during storage time. In the present study, the effects of polyethylene film containing 1 and 2% zinc oxide nanoparticles as nanocomposite packaging and film without nanoparticles as a control were evaluated in order to maintain some quality characteristics of Mazafati date fruit in two storage temperatures of 4 and 25 °C for 120 days. The results of analysis of variance showed that the effects of nanocomposite film, temperature and storage time on the studied parameters of Mazafati date were significant (p <0.05). The least changes in quality parameters of weight loss, pH, titratable acidity, total soluble solids, total phenolic content and total and reducing sugar contents were observed in date samples packed in 2% nanocomposite film stored at 4 °C. The change in control sample stored at 25 °C was significantly higher than other samples. In addition, the use of nanocomposite packaging reduced the microbial growth rate (total aerobic mesophilic bacteria, and mold and yeast) compared to the control sample. With increasing storage temperature from 4 to 25 °C, an increasing trend was observed in microbial growth and changes in the quality parameters of all samples, which indicated a decrease in the quality characteristics of the date fruit. Considering the studied parameters, nanocomposite packaging containing 2% zinc oxide had better performance than nanocomposite packaging containing 1% zinc oxide. In general, the use of nanocomposite film containing 2% zinc oxide nanoparticles is suggested to maintain the quality characteristics of Mazatifi dates at a temperature of 4 °C.

Tyrosinase, the enzyme responsible for biosynthesis of melani pigments has a special place. It is a metaloenzyme containing copper ions that catalyses two distinct reactions in the pathway of melanin biosynthesis. The monophenolase activity leads to hydroxylation of phenylalanin and the oxidation of 3, 4 dihydroxy phenylalanin to O-dopaquinon is through its diphenolase activity. Inhibitors and activators of the enzyme has a wide variety of effects on human health as well as in industrial applications. Considering the importance of pigments in human skin and hair and the role of tyrosinase in the production of melanin pigments, in the present research three important skin medications were selected for their effect on tyrosinase activity. In practical section, the enzyme was first extracted from banana skin followed by its characterization. The kinetic parameters were then investigated in the presence and absence of benzocaein, zinc oxide and kojic acid and the Michaelis Menton as well as Linweaver Burk plots were obtained. The results indicated that tyrosinase extracted from banana skin is similar to mushroom tyrosinase and its optimum temperature is higher than known tyrosinases. Therefore, by bearing in mind its low priced source, it can be recommended as an alternative to the commercial enzyme from mushroom. The results also showed that all three medicines were un-competitive inhibitors of tyrosinase. They reduced the maximum rate, Vmax of enzymatic reaction with no effect on Km. The highest inhibitory activity was obtained for zinc oxide.

This experiment was conducted to investigate the effects of different sources of zinc on performance, egg quality, and immune system and blood parameters of Japanese laying quails. Total of 160 layer quails were allocated in 4 treatments include: 1) Basic diet as control, 2) Basic diet + 50 mg zinc/kg of diet from nano zinc oxide (n-ZnO), 3) Basic diet + 50 mg zinc/kg of diet from Availa-Zn as organic source (Availa-Zn) and 4) Basic diet + 50 mg zinc/kg of diet from zinc oxide as inorganic source (ZnO) in a completely randomized design with 4 replicates. Commercial traits included feed intake (FI) Feed conversion ratio (FCR) egg production; Egg quality charctresitics were weekly evaluated. Different sources of zinc didn’t show the significant effects on feed intake, haugh unit, egg weight and production (P>0.05). But Availa-Zn and n-ZnO improved FCR as compared to control (P<0.05). Eggshell thickness was higher in Availa-Zn group than other experimental groups (P<0.05). There were significant differences in yolk index, eggshell resistance and yolk color of n-ZnO versus control group (P<0.05). The toe web swelling reaction as the immune response was significantly higher in n-ZnO than control group at 24 hours post-injection of PHA-P (P<0.05). Different blood parameters of hepatic enzymes (alkaline phosphatase, alanine transferase, aspartate aminotransferase) and biochemical parameters (cholesterol, triglyceride, HDL, LDL) were not affected by experimental treatments (P<0.05). According to the results, it seems addition of Availa-Zn can improve the egg quality and performance of Japanese layer quails in comparison with the nano and mineral forms zinc supplementation.

In this research, zinc oxide nanoparticles (ZnO) were synthesized using apple extract, and then the physical and chemical properties of ZnO nanoparticles were evaluated using SEM, XRD, EDS, UV-Vis and FT-IR. The average size of ZnO nanoparticles using Debye-Scherrer equation was estimated at 10 nm. The nanoparticles synthesized by this method (using apple extract) exhibited antimicrobial properties against Candida albicans, which showed the diameter of the halo created by the specimen in this fungus was 26 mm. The XRD spectrum represents the formation of zinc oxide nanoparticles and is consistent with earlier reports. According to the SEM spectrum, zinc oxide is composed of uniform particles. According to the results of the EDS test, the presence of Zn in the synthesized nanoparticles has been confirmed using apple extract. In this research, zinc oxide nanoparticles (ZnO) were synthesized using apple extract, the physical and chemical properties of ZnO nanoparticles were evaluated using SEM, XRD, EDS, UV-Vis and FT-IR evaluation methods. The average size of nanoparticles ZnO was estimated using a 10-nm DSS equation. The synthesized particles with this method (using apple extract) showed antimicrobial properties against Candida albicans, which showed that the diameter of the halo created by the sample The mushroom was spotted at 26 mm.

Aims: Essential oils are a complex of volatile compounds obtained from different parts of plants. Cinnamon (Cinnamomum zeylanicum) essential oil (EO) is known as a suitable source of antibacterial compounds. The aim of present study was to investigate the antibacterial activity of cinnamon EO and ZnO nanoparticles (NPs) against 2 strains of Listeria monocytogenes.
In this experimental study, 2 strains of L. monocytogenes (a standard strain and a fish isolated strain) were used. The antibacterial activity of cinnamon EO and ZnO NPs was assessed by well diffusion test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of cinnamon EO and ZnO NPs were also determined using broth macrodilution method. Moreover, the antibacterial properties of cinnamon EO and ZnO NPs were investigated in a liquid medium. The data were analyzed by SPSS 19 software, using one-way ANOVA and Tukey's post hoc tests.
Findings: The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of cinnamon EO were 16µl/ml and 64µl/ml, respectively. Furthermore, the MIC and MBC of ZnO NPs were 12.5mg/ml and 25mg/ml, respectively. The bacterial population significantly decreased with increasing the ZnO NPs and the cinnamon EO concentrations (p Cinnamon essential oil and ZnO nanoparticles have strong antimicrobial effects against L. monocytogenes, so that the cinnamon essential oil shows bacteriostatic effects on Listeria, but ZnO nanoparticles show bactericidal effect.

This study aimed to evaluate the antimicrobial effect of nano-fluids based on Eremurus spectabiils extracts against Staphilococcus aureus, Escherichia coli and Salmonella enterica in in-vitro condition. The extract was obtained by maceration. Disc diffusion method was used for determining the antibacterial activity of the extract at three concentrations: 200, 250, 300 mg/ml and zinc oxide nanoparticles at 1000 ppm. Results showed no inhibition zones for the alone extract while ZnO nanoparticles led to clear zone up to 23mm. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was determined using micro broth dilution method. The highest MIC and MBC was gained for the extract containing ZnO nanoparticles respectively at 12.5 and 25 mg/ml for Staphilococcus aureus. According to the findings, although the ethanolic extract had no inhibitory activity, yet addition of nanoparticles improved the antimicrobial activity which enables the extract to be used as a natural preservative in food and pharmaceutical industries.