In this study, the characterization of fatty acids and secondary metabolites in seeds three cultivars Opuntia ficus-indica L. (O. ficus-indica, yellow, orange, green) harvested from Souk Ahras area Northeast Algeria was performed. The antioxidant activity seed extracts also assessed by using two methods, namely FRAP DPPH tests. Results show that total phenolic content (TPC) ranged 63.02 to 81.8...