Volatile cleavage products of autoxidized soybean oil

Abstract

Summary Volatile odor principles of reverted soybean oil collected at very low temperature have been fractionated into rancidity and reversion components by adsorption on silica gel. These principles apparently contain aldehyde groups since they can no longer be detected organoleptically after the addition of aldehyde reagents. Isolations of individual aldehydes within the rancid and reverted fractions were made by forming the 2,4‐dinitrophenylhydrazones and chromatographically separating these colored derivatives. Identifications were based upon melting points, ultimate analyses, and adsorption data. The following aldehydes were identified: acetaldehyde, propionaldehyde, α‐pentenal, and hexanal. There is strong evidence that crotonaldehyde is also present although not completely resolved from propionaldehyde as dinitrophenylhydrazones.

Volatile decomposition products of the oxidative polymers of ethyl linolenate

“…All of these compounds have been isolated from oxidized soybean oil (4,6,7,8,10,12). Aeetaldehyde, propionaldehyde, and alpha pentenal have been identified, and possibly erotonaldehyde was also present.…”

Thermal decomposition of individual positional isomers of methyl linoleate hydroperoxide: Evidence of carbon‐oxygen bond scission

“…While the manner of oxidation of unsaturated fatty acids by enzymic oxidation and autoxidation to form either single isomers or mixtures of isomers of hydroperoxides is well established, the pathway by which they decompose to yield cleavage products is still poorly understood. In previous studies (4,6,8,9) in this area, autoxidized fats or unsaturated fatty acid derivatives have been used. The further decomposition of the alkoxy radical involving carbon-carbon bond scission forms a major pathway for the generation of cleavage compounds.…”

CARBONYLS IN OXIDIZING FAT. I. SEPARATION OF STEAM VOLATILE MONOCARBONYLS INTO CLASSESa

“…I n general, applications of the above methods have indicated a close relationship between peroxides and carbonyl values. Total carbonyl values, therefore, also appear not to be specific for rancidity.Consideration of these facts, together with the well-known sensitivity of taste, leads to the assumption that rancid flavors may be due to some particular type of carbonyls (8,9,14,15,27), the proportions and rate of formation of which are influenced by the composition of the glycerides, catalysts, enzymes, and anti-oxidants present, and processing and storage conditions. Henick, Benca, and Mitchell (23) have developed a method for determination of total saturated and unsaturated carbonyls as hexanal and crotonaldehyde.Applications (23,38) of this method showed the rate of increase of saturated carbonyls exceeded that of the 2-enal class.…”

“…Henick, Benca, and Mitchell (23) have developed a method for determination of total saturated and unsaturated carbonyls as hexanal and crotonaldehyde.Applications (23,38) of this method showed the rate of increase of saturated carbonyls exceeded that of the 2-enal class. The method does not take into account other classes of carbonyls that may be present.In studies of autoxidative mechanisms (6,8,9,22,25,27,28,44,45,46) one or more compounds of the following classes have been identified : saturated aliphatic aldehydes, saturated ketones, 2-en-l-als, 2,4-dienals, and dicarbonyls.…”