Some carbonyl flavor compounds of oxidized soybean and linseed oils

Abstract

Evidence is presented that 2,3‐pentanedione, as well as diacetyl, contributes to the buttery flavor found in the early stages of oxidation of soybean oil. Components with a fishy and potatoey flavor were found in distillates from soybean oil that had a fishy or paint‐like flavor. Linseed oil proved a reliable source of these flavor compounds. The fishy compound was identified ascis‐4‐heptenal and the potatoey compound is probably 2,4‐pentadienal. Mechanisms for the production of these compounds are suggested.

Density functional theory and RRKM calculations of decompositions of the metastable E‐2,4‐pentadienal molecular ions

“…2(A)), the more abundant the isomer (Fig. 5(B) [4], where a i is, in turn, the sum of all the decomposition rate coefficients of the ion i (i = 1, 2, 3 or 4) which are different from those of reversible steps of Scheme 2(A), i.e. a 1 = k 5 + k 6 , a 2 = k 7 + k 8 + k 9 , a 3 = k 10 + k 11 , and a 4 = k 12 + k 13 + k 14 .…”

“…2(A) and k 5 , k 10 and k 8 in Scheme 2) and ring closure (4 → 11 in Fig. 2 [4], but can be rewritten in terms of [M E ] as in Eqns (8) and (9), where k diso−H (Fig. 6) is the rate coefficient for H • loss from M E .…”

“…Therefore, the rate-controlling step approximation [22] can be used to reduce the set of simultaneous rate equations to one single rate equation of formation of the products b and b . The [4]) is then given by Eqns (10) and (11), where k M−CO is the rate coefficient for CO loss from M E .…”

“…[3] Their presence have been reported in the heated oil of soybean, [4] roasted peanut oils, [5] cooked chicken, [6] autoxidized linoleate and butter [3] and pyrolyzed samples of soil organic matter. [2] These compounds (Z-and E-isomers) have also been used as food additives [7] and can be synthesized from the corresponding 2,4-pentadienoic acid or 2,4-pentadienol.…”

The quantification of carbonyl compounds in oxidized fat by gas chromatography of the trichlorophenylhydrazones

“…Diacetyl and 2,3-pentanedione were reported to contribute to the buttery flavor found in the early stages of oxidation of soybean oil, while A-cis-heptenal and 2-trans-4-pentadienal were flavor contributors in autoxidized linseed oil (Seals and Hammond, 1965;Seals and Hammond, 1969). carbonyl impurities, and distilled slowly through a 100-cm column of porcelain saddles to remove high boiling impurities.…”