Thermal and metal‐catalyzed decomposition of methyl linolenate hydroperoxides

Abstract

AbstractMuch work has been reported on the volatile oxidative products of fats and their impact on flavor deterioration, cellular damage and the decrease in safety of fatcontaining foods. However, relatively little information is available on the mechanism of hydroperoxide decomposition. Pure methyl linolenate hydroperoxides were decomposed thermally at 150 C and catalytically with ferric chloride‐ascorbic acid at room temperature. The volatile decomposition products were collected on porous polymer (Tenax) traps and concentrated by gel permeation chromatography. The total volatile products showed significant differences in composition by capillary gas chromatography‐mass spectrometry (GC‐MS). Thermal decomposition produced much more methyl octanoate (60.1%) and less 2,4‐heptadienal (0.5%) than catalytic decomposition (13.2 and 60.8%, respectively). The volatiles from the ferric chloride‐ascorbic acid system also contained unique products tentatively identified by GC‐MS as isomers of chloromethyl butene. These results may have important implications in evaluating precursors of flavor deterioration in vegetable oils containing linolenate and in understanding better the biological significance of lipid peroxidation.