Antioxidant Characterization of Nigella and Olive Oils

Trans-cinnamic acid (purity ≥99%), p-cumaric acid (purity ≥98%), trans-ferulic acid (purity ≥99%), 1-decanol (purity 99%), p-toluenesulfonic acid, anhydrous toluene, luminol, H₂O₂, Tris-HCl buffer, lucigenin, xanthine, and xanthine oxidase were purchased from Sigma-Aldrich (St. Louis, Missouri, USA). DPPP was purchased from Cayman Chemical Co., Ann Arbor, MI, USA. Ethyl acetate, cyclohexane, ethanol, and potassium hydroxide (KOH) were purchased from Carlo Erba (Cornaredo, MI, Italy). Polysorbate 80 and phenolphthalein were purchased from A.C.E.F. (Fiorenzuola d’Arda, PC, Italy). Nigella oil from black cumin (Nigella sativa L.) seeds was produced by Tre Ponti Snr company (Polverigi, AN, Italy). Extra-virgin olive (EVO) oil from the Raggia cultivar of olive drupes (Olea europaea L.) was produced in a local olive mill. Chemical characterization of the EVO oil and Nigella oils has been reported in previous works [16 (link)].