Study of Antioxidant Properties of Leaf Extract of Levyticum Officinale and Its Effect on Soybean Oil Stability in Storage Conditions

Oxidation of lipids is one of the main problems in the maintenance and use of edible oils and fats. One of the most effective ways to delay the oxidation of lipids is the use of antioxidants. Adding chemical antioxidants has been shown to cause leukemia or cancer. Therefore, many plants that are excellent sources of phenolic compounds with strong antioxidant activity can be used as a suitable alternative to oxidative stability. In this research, the extract of the leaf Levyticum officinale was done using methanol solvent. The total phenolic compounds in the extract as well as its antioxidant activity were determined by investigating the inhibitory power of DPPH free radicals, then the antioxidant effects of the extract at different concentrations on oxidative stability of soybean oil was evaluated by measuring the peroxide value and the index of thiobarbituric acid (TBA) and the effect of synthetic antioxidant BHT has been compared. The results showed that by increasing the concentration of extract, the amount of phenolic compounds present in the extract increased as a result of its antioxidant activity, with the highest concentration of these compounds in the concentration of 1000 ppm, which was equal to 0.706 mg Ga / gr Extract . The highest antioxidant activity belonged to the highest concentrations of extract (1000 ppm) with 88.59%. Results of the test of peroxide value and TBA index showed that over time, concentrations of 800 ppm and 1000 ppm of the extract could well control the oxidation of soybean oil and would be better than synthetic antioxidant BHT. Therefore, according to the results obtained from this study, the extract of the plant can be used as a source of natural antioxidants to prevent the oxidation of oils and oil-containing foods.