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The yield and quality of oil extracted from common kilka (Clupeonella cultriventris caspia) through a novel extraction technique with supercritical fluid CO₂ and also ethanol co-solvent extraction at 30 MPa pressure and 58°C temperature of for 90 min were compared. Addition of ethanol co-solvent significantly increased the total oil yield (p˂0.05). Moreover, the qualitative characteristics of the extracted oil with ethanol modified the solvent acidity, peroxide and TBA index considerably less than the oil extracted by supercritical fluid CO₂. Fatty acid composition of the oil extracted with the two extraction methods showed there was no significant difference in SFA and PUFA fatty acids (p˃ 0.05). In general, the two methods used in this work didn’t considerably affect the fatty acid composition of the extracted oil.

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In addition to health effects, plant extracts can be used as natural preservatives with antioxidant and antimicrobial properties in the food industry. In this study, effect of antioxidant and antimicrobial properties of ethanolic extracts of watercress on the chemical and microbial quality of rainbow trout fillet at refrigerator temperature for 12 days was investigated. After drying the leaves at darkness and room temperature extract was extracted with 45, 65, 75 and 96% ethanol solvents for 24 hours at 65 °C. The results showed a significant difference (P≤0.05) in yields and phenolic content, 0.1 mg /ml of extract 65% with an extraction efficiency of 20% the highest amount of total phenol (88.60 ± 2.46%), DPPH (84.73 ± 0%); and ABTS (83.83 ± 0.06%) were. Also, the growth inhibition of the pathogenic bacteria Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella enteritidis in sample extracted with 65% ethanol had a significant difference with other extracts (P≤0.05). Rainbow trout fillet samples in 65% ethanol extract showed lower levels of TVB-N, PV and TBA to the control treatment during storage (P≤0.05). Rainbow trout fillet samples in 65% ethanol extract showed lower levels of TVB-N, PV and TBA indices of fillets compared to control treatment during storage (P≤0.05). Talking about bacterial index, the amount of total and pseudomonas bacteria in the treatment containing the extract did not reach the maximum allowable limit (10⁶ cfu /g^-1) by the twelfth day, Indicates the effectiveness of the extract on increasing the shelf-life of fillets compared to the control.
 

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Aim: The objective of the current study was to evaluate the effectiveness of various extraction techniques, namely supercritical carbon dioxide (SC-CO₂), ultrasound, and enzymatic methods, in comparison to the conventional wet reduction method, in terms of oil yield, quality attributes, and fatty acid composition in common kilka oil.
Materials & Methods: Mentioned methods were used to extract fish oil. Then, their quality oxidation, including PV, TBA, FFA, and CD, and fatty acid composition were evaluated.
Findings: The study's findings revealed that the SC-CO₂ extraction method exhibited the most favorable outcome in terms of extraction yield, achieving a remarkable rate of 89.6%. The lowest oxidation indexes including PV (1.78 ± 0.19 mmol.kg^-1), TBA (0.54 ± 0.03 mg MA.kg^-1), FFA (35.49 ± 0.52 mg FFA.g TAG^-1), and CD (7.61 ± 0.34 %) was found in oil extracted with SC-CO₂ method. The fatty acid profile of oil extracted by SC-CO₂ exhibited higher polyunsaturated fatty acid (PUFA) (29.81 ± 0.27) and lower saturated fatty acid (SFA) (27.64 ± 0.20) and monounsaturated fatty acid (MUFA) (34.78 ± 0.67) than those obtained by the other extraction methods (p > 0.05). The n-3/n-6, PUFA/SFA, and EPA + DHA/C16 ratios were higher for oil extracted by SC-CO₂ than the other three methods. Conclusion: The common kilka oil, extracted through supercritical carbon dioxide (SC-CO₂), can be regarded as an abundant source of crucial polyunsaturated fatty acids belonging to the n-3 series.
 

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Rainbow trout have found a good place in the household food basket due to their valuable nutritional properties. Therefore, supply in the form of hygienic packaging of this product due to CORONA pandemic in the country will be inevitable. This research has been done in order to provide intelligent packaging with the ability to detect microbial spoilage of rainbow trout. Fish fillet was packaged with H₂S gas sensor based on FeCl₃/Cellulose acetate. These packages were examined for total bacteria, temperatures swing, H₂S producing bacteria and Escherichia coli (1×10⁴ CFU/ml) during storage at 25 ° C for 3 days as well as storage at 4 ° C for 16 days. After imaging the correlation, the color changes of the sensor were calculated and evaluated as the color value. Sensor performance in terms of color change was significant (P <0.05) and the correlation between sensor color value and total bacterial growth in a 3-day period was 0.901. In order to accurately identify the growth of Escherichia coli, the correlation of Pearson color value and bacterial growth was equal to 0.932. Also, in the study the correlation between the color value with the number of total bacteria, temperatures swing bacteria and H₂S producing bacteria were 0.835, 0.869 and 0.836, respectively. Using a sensor with a combination of iron (III) chloride and cellulose acetate to determine the microbial spoilage of rainbow trout can be used in the future as a consumer-centric quality control method that can be commercialized.

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In this study, residues of imidacloprid (Confidor) were measured in greenhouse cucumbers in Mazandaran Province, Iran. Confidor 200 SL was applied at the recommended rate (30.0 g ai ha-1) and its double (60.0 g ai ha-1). Samples were collected at 1 h to 21 days after application and analyzed to determine the content and dissipation rate of Imidacloprid. . Analysis was carried out by the QuEChERS method using HPLC-UV. The average initial deposits of imidacloprid on the cucumber fruits were found to be 1.93 and 3.65 mg kg-1 at the single and double dosages, respectively. Results showed that Imidacloprid was rapidly dissipated in cucumbers following a first order reaction kinetics at both application rates. The amount of dissipation in 21 days was 94.48% and 99.18% for, respectively, the single and double dosages. Residues of imidacloprid dissipated below the maximum residue limit (MRL) of 1 mg kg_1 in 3 days. Half-life (T1/2) for degradation of imidacloprid in cucumber was observed to be 3.40 and 2.70 days at the single and double dosages, respectively. A waiting period of 3 days is suggested for safe consumption of cucumber. Also, results showed that the dissipation was dependent on the initial application dose and followed a first order rate kinetics.

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Mercury is a highly toxic and accumulative metal and its compounds, especially methyl mercury, are neurotoxins which cause blockage of the enzyme sites and interfere in protein synthesis. The fate of inorganic, mercury ions in nature is its turning into methyl mercury due to the aerobic action of microorganisms. Mercury is a toxic metal that causes the serious environmental problems. The main sources of mercury ions in aquatic ecosystems are divergent, chloralkali wastewater, oil refineries, power generation plants, paper and pulp manufacturing, rubber processing and fertilizers industries. Various methods have been used for removing heavy metals from aqueous environment such as reverse osmosis, chemical precipitation, ion exchange, coagulation and adsorption. Many carbon-based nanoparticles (CNTs) have been developed to remove heavy metals from aqueous media. They are promising material for numerous applications due to their unique electrical, mechanical, thermal, optical and chemical properties. In addition, CNTs are proven to be superior adsorbents for several divalent metal ions in water, because of their capability to establish (π–π) electrostatic interactions as well as for their large surface areas. Therefore, they have received considerable attention for usage in analytical chemistry and environmental remediation. Multi-walled carbon nanotubes (MWCNTs) were the first observed CNTs involving of up to several tens of graphite shells. The sorption capability of MWCNTs is related mainly to the functional groups attached on its surface. Generations of functional groups on the surface carbon nanotubes improves the reactivity and provides active sites for further chemical modifications. Many researchers have developed amino and thiol functionalization on carbon-based adsorbents and CNTs in order to increase the adsorption capacity, selectivity and removal efficiency of heavy metals and organic compounds. Among these functional groups, the thiols have an excellent binding ability to some metals such as silver, mercury, copper, nickel and zinc. In present study, multi-walled carbon nanotubes were functionalized in four stages to create thiolated multi-walled carbon nanotubes (MWCNTs-SH). The synthesized amino and thiolated MWCNTs were characterized by Fourier transform infrared spectroscopy (FT-IR) and elemental analysis (CHNS) to ensur successfully entailing the functional groups on MWCNTs surface. The efficiency of all synthesized MWCNTs in mercury removal was investigated. MWCNTs-SH was more efficient rather than other synthetized adsorbents in mercury removal from aqueous solutions. Increasing in adsorbent dosage concluded an enhanced mercury removal. Solution pH has a more effect on mercury removal. When the pH increased from 2 to 8 the removal percentage ranged from 9.8 to 92%. The data fitted by Langmuir isotherm model (R2=0.966) better than Freundlich model (R2=0.935). The obtained maximum adsorption capacity (qm) by Langmuir model was 206.64 mg/g while its experimental value was 160.90 mg/g and was higher than that reported in other literatures. Thus the prepared synthetized adsorbent has high efficiency for mercury removal from aqueous solutions.

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Composting is certainly one of the most natural types of recycling process. One of the problems during this process is the management of leachate that adversely affects human and ecological health in the area. Leachate is a complex organic compound which is difficult to be degraded biologically by conventional methods. Advanced oxidation processes (AOPs) have been widely studied for the degradation of diverse types of industrial wastewaters. The purpose of the study was aimed to evaluate the efficiency of hydrogen peroxide with ultraviolet light (H2O2/UV) for the treatment of high chemical oxygen demand (COD) strength compost leachate, color and turbidity using response surface methodology (RSM) under central composite design (CCD). The various operation conditions such as initial pH, dose of hydrogen peroxide, and UV-contact time was examined in order to optimize the maximum COD and color removal and turbidity of the compost leachate. The total number of 20 experimental runs was set. Optimal condition obtained for H2O2/UV process were initial pH 7.5, dose of hydrogen proxide 2.3 mL/L, and UV-contact time 95 min. In these conditions, the removal of COD and color and turbidity for H2O2/UV process was 12.32%, 20.83%, and 8.68 NTU, respectively. The results indicated that the H2O2/UV process has been successful in reducing turbidity but in COD removal efficiency is not well. Composting is certainly one of the most natural types of recycling process. One of the problems during this process is the management of leachate that adversely affects human and ecological health in the area. Leachate is a complex organic compound which is difficult to be degraded biologically by conventional methods. Advanced oxidation processes (AOPs) have been widely studied for the degradation of diverse types of industrial wastewaters. The purpose of the study was aimed to evaluate the efficiency of hydrogen peroxide with ultraviolet light (H2O2/UV) for the treatment of high chemical oxygen demand (COD) strength compost leachate, color and turbidity using response surface methodology (RSM) under central composite design (CCD). The various operation conditions such as initial pH, dose of hydrogen peroxide, and UV-contact time was examined in order to optimize the maximum COD and color removal and turbidity of the compost leachate. The total number of 20 experimental runs was set. Optimal condition obtained for H2O2/UV process were initial pH 7.5, dose of hydrogen proxide 2.3 mL/L, and UV-contact time 95 min. In these conditions, the removal of COD and color and turbidity for H2O2/UV process was 12.32%, 20.83%, and 8.68 NTU, respectively. The results indicated that the H2O2/UV process has been successful in reducing turbidity but in COD removal efficiency is not well. The results indicated that the H2O2/UV process has been successful in reducing turbidity but in COD removal efficiency is not well.

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Mesoporous activated carbon production from lignocellulose waste for removing reactive dyes Blue 19 and Blue 21 from aqueous solution Introduction. Reactive dyes have been increasing in textile industries for dyeing natural and synthetic fibers. Discharge of dye- bearing waste-water makes an adverse effect on aquatic environment because the dyes give water undesirable color. The major environmental and health problems associated with water pollution caused by the discharge of untreated textile effluent are due to disorders in the aquatic environment because of use of toxic chemicals. The aim of this study was to investigate the adsorption potential of as-produced activated carbon from grape wood residue (Vitis Vinifera) in order to remove Reactive Blue 19 (RB19) and Reactive Blue 21 (RB21) dyes from aqueous solution. Activated carbon is the most common adsorbent for the removal of many dyes.Activated carbons are made from various agricultural wastes by physical and chemical activation. The preparation of activated carbon from agricultural waste could increase economic return and also provides an excellent method for the solid waste disposal thereby reduce pollution. Method: The adsorbates in this study included three reactive dyes, Reactive Red 23 (RR23), Reactive Blue 19 and Reactive Blue 21. All dyes were commercial grade and employed without further purification. The activated carbon was synthesized from grape wood biomass by activation of phosphoric acid (H3PO4) with impragnation ratios of 1:1 1:2,1:3, 1:4. The FTIR, BET, and SEM techniques were used to characterize the as-prepared carbon materials. In addition, dye adsorption experiments were carried out, which measurements are taken for all of the samples under in the same condition, at pH of 2, adsorbent dose of 0.01 g/l, initial dye concentration of 250 mg/l, sworking volume of 100 ml, and contact time of 120 min. Results and discussion: The results showed that the carbon sample activated under imprenation ratio of 1:4 and temperature of 600oC, that obtained a special surface area of 1850 m2/g, and total pore volume of 2.40 cm3/g, and pore size distribution of mesoporous at 86%, had maximum adsorption capacity of 1932 and 908 mg/g for RB19 and RB21 dyes, respectively. The adsorption behaviors of three reactive dyes (Reactive Blue 19 23, Reactive Blue 21) onto this biomass activated carbon were investigated in batch systems. The experimental data were analysed by the Langmuir, Freundlich and Sips models of adsorption. Equilibrium data of dyse fitted well with the Sips model. The rates of adsorption were found to conform to the pseudo-second-order kinetics with good correlation. The equilibrium adsorption capacity of the Activated carbon was determined with the Langmuir equation found to be 1914 mg/g for Reactive Blue 19 and 1195 mg/g for Reactive Blue 21. Conclusion: This study showed that activated carbon produced from annual pruning vineyards waste has a high potential in the treatment of textile wastewater. Also results indicate that Activated carbon from grape wood could be employed as low-cost alternative to commercial activated carbon in wastewater treatment for the removal of acid dyes. Keywords: Activated carbon, lignocellulose waste, Grape wood, Blue 19, Blue 21

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Chlorpyrifos is widely used to control various insect pests on greenhouse cucumbers in Iran. In this study, the effects of the household processing such as washing, peeling, and refrigeration storage on the reduction of residue levels in cucumbers were investigated in different groups. Samples were collected at 1 hour to 14 days after application of chlorpyrifos and analyzed to determine the content of chlorpyrifos. Analysis was carried out by the QuEChERS method using GC-NPD. Residue levels in samples throughout a period of 14 days showed a gradual and significant (P< 0.05) decrease in contents of chlorpyrifos. The half-life (t_1/2) of chlorpyrifos applied to cucumbers was 1.9 days. Chlorpyrifos was detected in concentration ranges of 0.02-4.73 mg kg^-1. Household processing, such as washing, peeling and refrigeration storage, was effective in reducing the residue levels. Peeling was the most effective way to reduce residues in the cucumbers. Obtained results showed that a waiting period after chlorpyrifos application and household processing are required for safe consumption of cucumber.