In the present study we report the characterization of benzylglucosinolate (BG) isolated from papaya (Carica papaya L.) seeds. A methanolic extract was fractionated and further purified by solid phase extraction (SPE). It was analyzed by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and nuclear magnetic resonance spectroscopy (H-1 and C-13-NMR) as well, and the target compound BG was identified by these two techniques. The effect of BG on lipid oxidation in edible vegetable oil (EO) was shown by observing some lipid oxidation products (linoleic acid hydroperoxides, LHP; hexanal, HEX; nonanal, NON; thiobarbituric acid reactives species, TBARS). BG reduced lipid oxidation production in EO by over 80%, as compared to a control sample and in this way has proved to be a useful antioxidant, even more effective than some antioxidants used by food industry.