M.A. Thesis:

study of antioxidant effect of sesume leaf extract on soybean oil stability in during storage

In recent decades, the interest of researchers in investigating the presence of antioxidant compounds in agricultural products, especially fruits and vegetables, has increased dramatically. The health benefits of antioxidants and their role in preventing diseases have been major causes of this increase. In this research, the extract of methanolic leaves of sesame seeds was extracted and then extract extracted in 5 concentrations of 500, 600, 700, 800 and 900 ppm in terms of the inhibitory power of free radicals and polyphenol compounds were compared and compared with a sample of BHT 200 ppm Increasing the concentration of extracts from 200 to 900 ppm significantly increased the inhibitory power of free radicals and the amount of polyphenolic compounds, but the treatment containing 600 ppm with 200 ppm of BHT did not have a significant difference. The level of ppm 500 in terms of phenolic compounds was lower than BHT. In the DPPH test, the highest radical responses were found to be 800 and 900 ppm, which is statistically different from the mean comparison at 0.05 with BHT (ppm 200), which indicates a high content of polyphenolic compounds in sesame leaves. After performing the Folin and DPPH tests, ppm900 extracts, which had more antioxidant properties, were selected to perform the aeration experiments. In an oven test at 65 ° C in four days of day zero, day one, day two and third day, tests The index of peroxide, acid test and TBA were performed in the index of soybean soybean oil without antioxidants with high peroxide value, and also with the increase of peroxide increased over time, but in the two samples the difference was significant in the peroxide index But on the third day, due to the richness of the polyphenolic compounds in the sesame leaf extract and treatment Containing ppm900 showed less extract peroxide value and showed a significant difference with BHT (ppm200) at a significant level of 0.05. In the level of acidity, the non-antioxidant (control) sample showed an increasing trend, and also from the same First, it had a higher acidity index. In two other treatments, the extract containing 900 ppm of sesame leaves and BHT treatment showed a greater difference from the third day, with a significant level of 0.05 with extract-based oil. In the thubarbituric test, on the third day, there was a statistical difference between the two samples of oil containing extracts and oil containing BHT at 0.05.

Keywords: Natural antioxidants, oxidative stability, sesame leaf, soybean oil