2.3.7. Determination of radical scavenging activity The radical scavenging activity (RSA) ofthe oils was assayed by reduction of 2, 2 diphenyl 1-picrylhydrazyl (DPPH) radicals in toluene according to the procedure followed by Ramadan et al. (2003). A HPLC grade toluene solution containing 10−4 M DPPH. 50mg of oil sample was added to 4ml DPPH aliquot (10−4 M) in toluene solution in a test tube and mixed for about 20 s and kept aside for 60min at ambient temperature. Afterwards, the absorption of DPPH radicals was recorded at 515nm in a 1 cm quartz cell after 60min of mixing against a blank of pure toluene with DPPH radicals using UV-visible spectrophotometer (model UV-1601, Shimadzu Corporation, Kyoto, Japan). The radical scavenging activity was calculated using the following equation: