Studies on Discoloration of Oxidized Lipid by Gel Filtration

As it appears that gel filtration promises to be a powerful tool in the study on the discoloration of oxidized lipid, the discolored lipid and the oxidized lipid were subjected to gel filtration on Sephadex LH-20 or Bio-Beads S-X 3 with CHCl3: MeOH (2: 1) or benzene as a solvent.In the discoloration of oxidized linolenate by trimethylamine-blowing, the discoloration proceeded with the time of oxidation and was accompanied by a notable decrease in active groups such as peroxide and carbonyl. Most of the discolored products were fractionated into the largest molecular size fraction. Furthermore, the spot test with trimethylamine showed that the larger the molecular size of oxidized linolenate fraction, the stronger was the discoloration.On the basis of these results, the authors concluded that the discolored product was the large molecular size molecule produced by the reaction between the oxidized and polymerized lipid and trimethylamine.