Abstract:
The aim of this study was to evaluate the effect of different extraction methods( aqueous enzymatic method,solvent extraction method,cold- press method) on the fatty acids,physicochemical characteristics,phenolic compounds,tocopherol content,antioxidant activities and oxidative stability of sunflower oils. Antioxidant activity of oil was measured by 1,1- diphenyl- 2- picrylhydrazyl( DPPH) and β- carotene bleaching assays and2,2- azinobis( 3- ethylbenzthiazoline sulfonate)( ABTS) radical scavenging capacity. And the differential scanning calorimetry( DSC) was applied for evaluating the oxidative stability of sunflower oils extracted by different methods.Results showed that fatty acid content was not influenced by extraction method( p < 0.05).Cold- press method was found to be the best process for extracting oil with a favorable quality characteristics when compared to aqueous enzymatic method and solvent extraction method.Higher total phenolics content( TPC,0.29 mg / g),ortho- diphenol content( ODC,0.45 mmol / kg) and total tocopherol content( TTC,1090.81 mg / kg) and DPPH( IC
50,3.54 mg /m L) and ABTS( TEAC,652.33 μmol / L) scavenging capacities and β- carotene bleaching activity( C%,45.93%) were also obtained with solvent extraction method. Additionally,the effect of different extraction methods on the oxidation stability of sunflower oils was significant. The oxidative stability of solvent extracted sunflower oil was the greatest compared with those obtained other two extraction method.