Antioxidant activity of sesame cake extract

Sesame cake was extracted with methanol to obtain a crude antioxidant extract. The qualitative and quantitative analysis of antioxidants/lignans present in the extract was carried out by reverse phase high performance liquid chromatography (HPLC) using a C18 column. In this study, sesame cake was also subjected to successive extractions with solvents of differing polarity to get a purified antioxidant extract with higher antioxidant content and better activity. The antioxidant activity was evaluated using the β-carotene bleaching method, linoleic acid peroxidation method and free radical scavenging assay, using 2,2-diphenyl-1-picryl hydrazyl radical (DPPH). Results showed that crude extract was effective at 100 and 200 ppm levels and comparable with butylated hydroxy toluene (BHT) at 200 ppm, whereas purified extract showed comparable or better activities at 5, 10, 50, 100 and 200 ppm levels.