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Investigating the trend of temperature changes occurring in the Persian Gulf can be used to determine the pattern of climate change in the region and to study the impact of these changes on aquatic habitats in the Persian Gulf waters.  This study was carried out to investigate the changes in sea surface temperature and sea surface temperature anomaly in Kharg and Hendourabi islands by using Environmental Research Division's Data Access Program (ERDDAP) of National Oceanic and Atmospheric Administration (NOAA) and  daily sea surface temperature and sea surface temperature anomaly  were investigated over a 35-year period.The results showed that the average annual surface temperature increased by about 1 °C over 35 years in Kharg and Hendourabi Islands and the average annual sea surface temperature anomaly in these islands were increased by 2 °C. The slope of this increasing trend on Kharg Island was more severe than Hendourabi Island. The most significant bleaching event in the Persian Gulf occurred in 2016-2017, with the highest increase in temperature in 2017. As water temperatures continue to increase in the coming years, the living conditions of the Persian Gulf corals are likely to deteriorate, and only some resistant species can survive in the Gulf.

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The present study explores the chemical constitution and antioxidant activity of the essential oils of the aerial parts of Artemisia dracunculus L. and the flower heads of Matricaria chamomilla L. GC-MS analysis revealed the presence of (Z)-anethole (51.72%), (Z)-β-ocimene (8.32%), methyleugenol (8.06%), limonene (4.94%) and linalool (4.41%) in Artemisia dracunculus and (E)-β-farnesene (24.19%), guaiazulene (10.57%), α-bisabolol oxide A (10.21%), α-farnesene (8.7%) and α-bisabolol (7.27%) in M. chamomilla L.. The antioxidant activity (AOA) of the essential oils was investigated using DPPH• (2, 2′-diphenyl 1-picrylhydrazyl) free radical scavenging and β-carotene/linoleic acid methods. The essential oil EC50 values were determined as 3.19±0.13 and 5.63±0.20 mg ml-1 for A. dracunculus and M. chamomilla, respectively. Further, the A. dracunculus L. essential oil (ADEO) and M. chamomilla L. essential oil (MCEO) were able to reduce the oxidation rate of soybean oil under accelerated conditions at 60 °C (oven test).

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Dill (Anethum graveolens) is a plant belonging to the Apiaceae family rich sources for tocophorol and phenolic content, including antioxidant activity. These diet antioxidants are important as they protect human body against oxidative stress and therefore maintain appropriate health. The propose of this study evaluate  the effect of extraction methods (ultrasound and Microwave) and solvents (ethanol, ethanol/water (50:50), and water) on tocophorol and phenolic content and antioxidant properties of dill extracts are to determine the most suitable extraction method for optimal use of this product. The antioxidant activities of each extract are evaluated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH), b-carotene bleaching and oxidative stability index (OSI). In all antioxidant assays the ultrasound water/ ethanol and ultrasound-ethanol had highest antioxidant activity and they didn^’t have significant difference with synthetic antioxidant TBHQ. According to the result dill extract with the method of ultrasound ethanol/water and ultrasound- ethanol can be replace with synthetic antioxidant in food industries.  

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Present research studies the effects of bleaching and deodorizing parameters on physicochemical properties consisting of fatty acid compositions (FAC), iodine value (IV), saponification value (SV), refract index (RI) and also oxidative stability evaluation containing peroxide value (PV), acid value (AV), oxidative stability index (Rancimat test) and Anisidine value. The percentage of bleaching clay 0.8, 1.0 and 1.2 (w/w), the temperature of 200 and 220 (°C) and the pressure of 2 and 3 (mbar) were used to refine frying oil. The results indicated the bleaching and deodorizing process had no significant effect on the FAC, IV, SV and the RI of frying oils. Investigation on oxidative stability distinguished the increase of bleaching clay led to more degradation of fatty acid peroxides; thus decreasing PV. In spite of obtained result for PV, the Anisidine value increased at the end of bleaching step. The secondary oxidation products were removed more at higher temperature. Rancimat test presented a decrease in the samples exposed by high temperature and pressure due to more remove of phenolic compound.

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This study investigated the fatty acids profile, oxidative stability indices, and bioactive compounds of virgin and processed olive oils (Leccino and Frantoio cultivars). Results showed that fatty acid profile of the studied oils contained mostly oleic acid followed by palmitic and linoleic acid. Acid values of virgin Frantoio and processed Leccino were 0.78 and 0.18 mg KOH/g oil, with peroxide values (PV) of 8.74 and 6.03 meq O₂/kg oil, respectively. Virgin Leccino had the highest oxidative stability index with induction period of 18.83 h. The highest contents of phenolics, 321.14 mg/kg, tocopherols, 455.25 mg/kg, and sterols, 2189.1 mg/kg, were recorded in virgin Leccino oil. Laboratory processing of virgin olive oil decreased the phenolics to 70%, tocopherols to 50%, and sterols to 25%. Finally, based on the higher content of antioxidant compounds, the virgin Leccino oil had higher oxidative stability and bioactivity than Frantoio oil.

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Olive cultivars Bladi and Arbequina were collected and their oil was extracted (cold press). Oil was refined under bleaching and deodorization conditions for 30 minutes at 55-50°C and their property was compared with the virgin olive oil. Virgin and refined oils of the cultivars were processed by fryer heating at 180°C (intervals of 0, 1, 2, 4, and 8 hours) and indexes of fatty acid, free fatty acid, peroxide, thiobarbituric acid, polar compounds, conjugated dienes and trienes, Rancimat, color, total polyphenol, tocopherol, chlorophyll and carotenoid were compared. Results showed that these oils mainly contained oleic (48.69-60.18%), palmitic (18.31-27.02%), linoleic (7.54-18.58%), palmitoleic (3.9-3.08%), stearic (1.78-2.53%), and linoleic acids (1.87-0.22%). According to the results, it was recommended to refine virgin olive oil by mild bleaching and deodorization to save bioactive compounds. Due to the heating condition, the relative amounts of unsaturated fatty acids (22.37-50.6%), polyphenols, tocopherols, chlorophyll, carotenoid and oxidative stability decreased and the relative amounts of saturated fatty acids (14.2-17.1%), acidity, peroxide, conjugated dienes and trienes, polar compounds, and thiobarbituric acid increased significantly, but the colorant initially decreased and then increased (P< 0.05). Due to polar compounds, for frying process, mild refined oil was better than extra virgin oil.

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During the bleaching of edible oil, the color and many oil impurities are removed through the adsorbent which is usually the bleaching earth.  Although adsorbents containing silica have high bleaching capacity, the purpose of this study was to investigate the role of aluminium and magnesium oxides along with silica as the main component of adsorbent. The process was carried out with 1 and 2% of adsorbents consisting of different ratios of silica, aluminium and magnesium oxides. The amount of peroxide and acid values, chlorophyll, carotenoid, red and yellow colors, amounts of copper and iron of the bleached samples were determined. The results indicated that the effect of 2% of adsorbents was more effective than 1%  in reducing all of the investigated factors. The amount of 2% of the adsorbent containing 90% silica and 10% magnesium oxide reduced the peroxide value by 74.82% and the adsorbent containing 70% silica and 30% aluminium oxide reduced the acid value up to 50% (p˂0.05).  Combined adsorbents containing aluminium and magnesium oxides, especially those with 10 or 15% magnesium oxide reduced chlorophyll content significantly.  Adsorbents consisting of higher amounts of aluminium oxide were more effective to reduce carotenoids. Addition of aluminium and magnesium oxides had significant effect on reducing the amount of red color compared to the blank sample. The amount of copper decreased by about 50% compared to the blank sample (p˂0.05). The highest reduction in iron content was obtained using the adsorbent containing 70% silica, 10% aluminium oxide and 20% magnesium oxide. The results of this study showed that the adsorbents had a good performance during the bleaching process of soybean oil and the difference in bleaching depends on the consumed amount, the compounds of the adsorbent, especially aluminium and magnesium oxides, and the type of impurity.

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One of the most important steps in the refining process for edible oils is the coloring step. Decolorization is an absorption process that involves the use of acid-activated clay to remove undesirable components of oil. Therefore, it is necessary to optimize the parameters of decolorization, mainly temperature, time and concentration of decolorizing soil in order to prevent adverse changes of the oil in the next stages and during storage. In this research, corn oil was selected and the effect of changing the dyeing parameters on the chemical properties of the oil was studied in order to optimize the process. For this purpose, the effect of time (15, 25, 35, 45 and 55 minutes), temperature (80, 90, 100, 110 and 120 degrees Celsius) and the concentration of soil-dye remover (0.4, 0.6, 0.8) , 1 and 1.2 percent) was investigated using the statistical design of the response level in 5 levels by the Central Composite Design method with the aim of reducing the consumption of soil-dye remover. The effect of decolorization parameters on oxidative stability (peroxide number, anisidine number, totox number, free fatty acid amount, Rancimet test and specific absorption at 232 nm and 270 nm), decolorization efficiency (carotenoid amount) and bioactive compounds (sterols amount) in Corn oil was studied. The results showed that after optimizing the best conditions for the decolorization stage in corn oil in order to minimize impurities, preserve bioactive compounds, and minimize the consumption of decolorizing soil, the time of decolorization was 35.59 minutes, the temperature was 103.61 degrees Celsius, and the soil concentration The dye was 1%, which was able to meet 57% of expectations. The practical results did not show any significant differences with the theoretical values ​​and confirmed these results.

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The bleaching process is important in the refining operation of edible oils. In this study, bleaching parameters were changed to evaluate the best condition for optimizing of bleaching in corn and sunflower oils. For this purpose, the effect of time (15, 25, 35, 45, and 55 min), temperature (80, 90, 100, 110, and 120 °C), and bleaching clay concentration (0.4, 0.6, 0.8, 1, and 1.2%) was evaluated using response surface methodology as statistical design in 5 levels by Central composite design with the aim of reducing the consumption of bleaching clay. The studied factors were including carotenoids, sterols, tocopherols, pigment and cations. After optimization, the best conditions for bleaching of corn and sunflower oils was different. For corn oil, the best conditions was time 39.59 min, temperature 103.61 °C, and bleaching clay concentration 1%, which meet 67% of our expectations. For sunflower oil with the aim of reducing the consumption of bleaching clay, the best conditions were time 37.49 min, temperature 97.53 °C and bleaching clay concentration 1%, which satisfied 70% of our expectations. The practical results did not show any significant differences with obtained theory values ​​using response surface methodology and confirmed these results.