Evaluation of antioxidant properties of different Zizyphus fruit extracts and comparing their antioxidant activity with BHT in soybean oil

The zizyphus is include nutritional properties very useful, and is used to treatment of various diseases in traditional medicine.The aim of the present study was to evaluate the antioxidant properties of ethanol, methanol and water extracts of Zizyphus fruit in three different concentrations (600, 800 and 1000 ppm) and comparing the best extract with BHT(200 ppm) in soybean oil. Ethanol extract of Zizyphus in three concentrations of 600, 800 and 1000 ppm in all antioxidant tests (DPPH free radical scavenging assay, total antioxidant capacity and reducing power) performed better than methanol and water extracts. Also, methanolic extracts showed significantly better results in all tests compared to water extract. Compared with BHT, concentration of 1000 ppm ethanol and methanol extracts in DPPH and total antioxidant capacity tests, and concentration of 1000 ppm ethanol extract in reducing power test were better than BHT. In the peroxide value and TBA, selected extract of antioxidant (ethanolic extract) in concentrations of 800 and 1000 ppm had a significant (p