اکرم آقایی

The decline of natural forests has been caused urban afforestation to acquire a particular importance with the purpose of green space development level, therefore, the selection of appropriate plant species plays a substantial role in the development and stability of urban green space. The nutrients evaluation is significant in in selection of appropriate species for planting and in a way that species can be selected and supplemented by either consumption of the whole available nutrients in habitat or with their accompanying species.

The present study was conducted to evaluate the high consumption nutrients (Nitrogen, Phosphorus, Calcium, Carbon, Magnesium and Potassium) in the leaves of Mulberry, Ash, Tehran Eldarica Pine and Arizona Cypress in two summer and autumn seasons in four geographical areas (Jamshidieh Park, Sorkheh Hesar Park, Vard Avard Park and Shaghayegh Park) in Tehran. Also, retranslocation of nutrients was measured in four parks and three species (Mulberry, Ash and Tehran Eldarica Pine). At the end of the growing season, the mature green leaves (80 samples) and at the end of the autumn season, the fallen leaves (60 samples) were collected at the base of the tree and packed in zippered bags with the desired specifications on them and transferred to the laboratory. The leaves were washed with sterile distilled water to remove contaminants, then dried in an oven at 70 ° C for 24 hours and then ground. Chemical analyzes were performed using standard instructions. Statistical analyzes such as general comparison of means (one-way analysis of variance) and group means (Duncan test) were performed.

The results of this study showed that the average nutrients in summer leaves are higher than autumn leaves. In Sorkheh Hesar, Shaghayegh and Jamshidieh parks, in summer leaves, the highest amounts of nutrients related to calcium (62.66 mg/g in Shaghayegh Park) and in Alder was recorded. While in Vard Avard Park, the highest amount of this element was observed in mulberry (68.32 mg/g). In autumn leaves, in three parks of Shaghayegh, Jamshidieh and Vard Avard, the highest concentration of nutrients related to calcium (42.66 mg/g in Shaghayegh Park) and was recorded in mulberry. While in Sorkheh Hesar Park, calcium concentration was recorded in Alder (50.66 mg/g). Regarding the percentage of nutrient retranslocation in the studied species in Sorkheh Hesar Park Magnesium (63.04%) in Alder, in Shaghayegh Park Potassium (52.58%) in Mulberry, in Jamshidieh Park Potassium (63.79%) in Tehran Eldarica pine and in Vard Avard Park calcium (41.45%) in mulberry had the highest nutrient retranslocation.

The species studied in this study had different nutrients in their summer and autumn leaves. These species also retranslocation a different amount of each element. It is suggested that this issue be taken into consideration in the management and planning of urban forestry, and the tree species used, which are mainly the main tree species in urban forestry, should be classified based on the status of nutrients.

There are several methods to prevent oxidation of oils, one of which is the use of antioxidants. Antioxidants are substances that reduce, delay, or stop oxidation reactions. The use of medicinal plants and their active ingredients as natural antioxidants are now considered by researchers. Effective ingredients of plants such as the compounds in the extract and essential oils in the food industry are very important. Tanacetum balsamita is belongs toAsteraseae family. According to numerous applications of this plant in the fields of food and pharmaceutical, In this study, the compounds were isolated in essential oil and of water, methanol, hexane and chloroforms extracts of the plant. The type of existing compounds was identified. Their effect on oxidation of sunflower oil was studied.

The fresh shoots of the plant were collected from west of Isfahan in khordad 1397. Then they were dried in a dark place at room temperature. Essential oil was extracted by water distillation method using Clevenger's apparatus. Water, methanol, hexane and chloroform extracts were prepared by soaking method. The amount of phenol, flavonoids and terpenoid of the extracts were measured by Folin-Sycaltol, aluminum chloride colorimetric and separation in ether methods. The DPPH method was used to evaluate the antioxidant properties of each extract.100 grams of powdered plant in the balloon shed and a ratio of 1 to 5 added water heater was put on. The first 15 minutes of the temperature was set to 150 ° C and then the temperature was adjusted to 50 ° C. It takes 2 hours for the essential oil to form above the sweat. The essential oil was taken twice to obtain the desired amount of essential oil. Essential components were determined by GC-MS.Considering that the antioxidant capacity of the methanolic extract was higher than other extracts and was almost the same as that of the essential oils of the aerial parts.Therefore, they were used as antioxidants to prevent the oxidation of sunflower oil. Methanolic extracts with concentrations of 1000, 500 and 250 ppm were also added with 800 and 600 ppm and BHT antioxidants in two concentrations of 200 and 100 ppm in sunflower oil and 100 grams of refined sunflower oil without addition of extracts or any other combination As an example, the control was considered. The effect of extracts on delaying oxidative degradation in refined sunflower oil was determined by measuring peroxide value, barbituric acid number and oxidation resistance time of samples. The choice of extract used in oil stability was based on the amount of phenolic compounds present. The choice of extract used in oil stability was based on the amount of phenolic compound contents.Result s and

The results showed that methanolic extracts had the highest amount of flavonoid and total phenol (12.98 and 98.38 mg / ml), the chloroform extract had the highest amount of tripnoyid (1320.4 mg / g). Phenol compounds have been extracted with methanol and water solvents better than hexanes and chloroforms. Flavonoids are also extracted by methanol solvent than hexane, chloroform and water. Therefore, flavonoids in this plant are soluble in polar solvents rather than non-polar solvents. The highest percentage of inhibition was associated with methanolic extract with 68.66%. The inhibitory effect of this extract is mostly on non-flavonoids phenolic compounds. The compounds identified in the essential oil were 1, 8 cineole, beta-thujone, cyclopentanol, cyclohexane and the beta bisabolin. Increasing the concentration of extract and essential oil increased the antioxidant effect.During the study period, with increasing concentrations of extract and essential oil, the peroxide value increased.Delay in oxidation and their antioxidant effect.Therefore, the extract used in oil stability was based on the amount of phenolic compounds present.As the concentration of the extract increases, there will be more phenolic compounds. As a result of the increase in the number of hydroxyl groups in the reaction medium, the probability of hydrogen donation to free radicals followed by the inhibitory effect of the extract increases. The results of the study of oil oxidative stability containing different concentrations of extract and essential oil showed that methanolic extract concentration of 1000 ppm and essential oil at 800 ppm concentration compared to other concentrations and control sample was more effective in the oxidative stability of sunflower oil. They had a greater effect Compared to the synthetic antioxidant (BHT) at 200 ppm concentration. The highest oxidation resistance time was observed for samples in which the methanolic extract was used at a concentration of 1000 and an essential oil at a concentration of 800 mg / L. High levels of peroxide value show lower oxidative stability in oil samples. Increasing the concentration of extract and essential oil used to affect the amount of peroxide value, which was decreased by increasing the concentration during the test period. Antioxidants remain active during a certain period of time, and gradually their effect gradually decreases. As a result, increasing the storage time of oil samples under oxidation conditions, the amount of peroxide value increased. All of the antioxidants used in this experiment, had thiobarbituric contents lower than control. 1,8-Cinole and Tujun are more effective in preventing lipid oxidation than other essential oil compounds. Considering that these two substances are the major components of essential oil of the plant, the effect of the essential oil of this plant on the stability of sunflower oil is probably due to the presence of these compounds.Peroxides are the primary product of the oxidation of fats and can be estimated using the peroxide index. High levels of peroxide value show lower oxidative stability in oil samples. In all cases, the peroxide value has increased. The lowest amount was related to oil treatment with 1000 mg / L of methanolic extract, which was statistically different from that of synthetic antioxidant containing 200 mg / L oil and essential oil containing 800 mg / L. With increasing concentrations of extract and essential oil, the oxidation rate has decreased.

Therefore, they can be used as a source of natural antioxidants. By comparing the extracts it can be concluded that methanol is the best solvent for the extraction of phenol, flavonoids. On the other hand, the methanolic extract and essential oil of the plant have a high inhibitory effect. Methanol extract and essential oils with Suitable anti-radical effect can be replaced by BHT in sunflower oil.