Analysis of autoxidized fats by gas chromatography-mass spectrometry: VII. Volatile thermal decomposition products of pure hydroperoxides from autoxidized and photosensitized oxidized methyl oleate, linoleate and linolenate

摘要: To clarify the sources of undesirable flavors, pure hydroperoxides from autoxidized and photosensitized oxidized fatty esters were thermally decomposed in injector port a gas chromatograph-mass spectrometer system. Major volatile products identified methyl oleate, linoleate linolenate. Although are isomerically different position concentration than those esters, same major formed but relative amounts. Distinguishing volatiles were, however, produced each type hydroperoxide. The 9- 10-hydroperoxides oleate isomerized into mixture 8-, 9-, 10- 11-hydroperoxides similar to that oleate. Under conditions, linolenate did not undergo significant interconversion with corresponding esters. compositions decomposition explained by classical scheme involving carboncarbon scission on either side alkoxy radical intermediates. Secondary reactions also postulated, hydroperoxy cyclic peroxides (photosensitized oxidized) (both suggested as important precursors volatiles.