Volatile decomposition products of the oxidative polymers of ethyl linolenate

Abstract

Summary Oxidative polymers which had been isolated from autoxidized ethyl linolenate were oxidatively decomposed in a closed system at room temperature. The decomposition products were collected in appropriate traps and separated into various fractions on the basis of their volatility and solubility. The aldehydes and ketones thus obtained were converted into 2,4‐dinitrophenylhydrazones, chromatographed on silica gel, and the isolated 2,4‐dinitrophenylhydrazones identified by standard procedures. Methyl ethyl ketone, propionaldehyde, acetaldehyde, and alpha‐pentenal were positively identified, and evidence for the presence of crotonaldehyde and an unknown five‐carbon‐carbonyl compound was obtained. Acetaldehyde, propionaldehyde, and alpha‐pentenal have been isolated from the decomposition products of oxidatively decomposed reverted soybean oil by previous workers. If oxidative polymers of linolenate are present in reverted soybean oil, they could serve as precursors of the aldehydes and ketones which have been associated with flavor reversion.

Carbonyls in Qxidizing Fat. IV. The Role of Various Fatty Acid Components in Carbonyl Generation

“…Trace alk-Z-enal Cs could come from linolenate, but may not have, because the major linolenate alk-2-enal Cg should also be present. Chang and Kummerow (1953) found n-alkanals CS, Cg, and Cs among the volatile decomposition products of linoleate oxidative polymers. The compound n-alkanal C5 was not detected in this study.…”

“…Kawahara et al (1952) found alkanal C, and C3 and alk-2-enal Cg among the volatile cleavage products of oxidized linolenate. Johnson et al (1953) found methyl ethyl ketone, alkanal CZ and Ca, and alk-2-enal Cj in the products of decomposed oxidative polymers of linolenate. A compound of an apparently new class was detected in small amounts in the oxidized linolenate.…”

“…Chang and Kummerow (1953) found n-alkanals CS, Cg, and Cs among the volatile decomposition products of linoleate oxidative polymers. The compound n-alkanal C5 was not detected in this study.…”

Autoxidation of Fish Oils. I. Identification of Volatile Monocarbonyl Compounds from Autoxidized Salmon Oila, b, c

“…Isolation and characterization of the autoxidation products of fats and oils have been the subject of considerable research in the past decade (Badings, 1959;Brekke and MacKinney, 1950;Chang and Kummerow, 1954;Gaddis and Ellis, 1959b ;Johnson et al, 1953 ;Swift et al, 1945Swift et al, , 1949. The reagent 2,4-dinitrophenylhydrazine (DNP) forms crystalline derivatives with aldehydes and ketones, with characteristic melting points.…”

Composition and stability of pecan oils

“…Regarding the studies on stability of oils and fats, much work has ~een done (3,10,11,12,13,14,15,16 The hydroperoxides thus form~d may cleave in one or two ways yielding alkanals, alkenals, alk-dienals, dicarboxyls, alcohols, and hydrocarbons depending on the fatty acids involved (13,14,15). Thermal decomppsition of the hydroperoxides formed from unsaturated fatty acids yields about 90 percent by weight of dimeric polymers (16).…”