ISOLATION AND IDENTIFICATION OF AN ANTIOXIDATIVE COMPONENT IN CANOLA-MEAL

Canola meal was extracted with 95% ethanol at 80 degrees C. The dried crude extract was dissolved in methanol and fractionated on a Sephadex LH-20 column. Seven major fractions were isolated according to UV abs orption and contents of phenolics and sugars. Antioxidant activity of these fractions was evaluated in a beta-carotene/linoleate modelsystem . Fraction IV showed the best antioxidative effect by exhibiting the h ighest preventive activity against the bleaching of beta-carotene. Thi s fraction was further separated by thin-layer chromatography. Four ma jor antioxidative bands were present; the band with R(f) value of 0.50 was found to be most effective in preventing oxidation of beta-carote ne. This band was isolated and characterized by UV, MS, IR, H-1 NMR, a nd C-13{H-1} NMR techniques. The active compound was identified as 1-O -beta-D-glucopyranosyl sinapate.