Soybean oil, oxidation

A good correlation is observed between ANV predicted from the absorbance in the 1100 to 2200 nm NIR region and ANV determined by the Cd 18-90 AOCS" ° official method, using UVD at 350 nm. The NIR spectroscopic method was applied to determine ANV for oxidized soybean oil °. ... 

Hydroperoxide formation by the ene reaction path may lead to formation of conjugated double bonds in polyunsaturated fatty acids (see Section V.A) this reaction is concurrent with POV increase. An increase of the CDV, as measured from the absorbance at 233 nm, therefore indicates oxidation of polyunsaturated lipids. A strong correlation exists between CDV predicted from the absorbance in the 1100 to 2200 nm NIR region and CDV determined by the Ti Ia-64 AOCS official method , by UV spectrophotometry at 233 nm. The method was applied to determine CDV for oxidized soybean oil. A secondary absorption maximum of lesser intensity appears in the 260-280 mn range, and is assigned to ketone dienes . 

Gas chromatographic (GC) methods have been used for determining volatile oxidation products. Static headspace, dynamic headspace or direct injection methods are the three commonly used approaches. These methods were compared in an analysis of volatile compounds in an oxidized soybean oil. It was found that each method produced significantly different GC profiles (Frankel 1985). The dynamic headspace and direct injection methods gave similar results, but the static headspace is more sensitive to low molecular weight compounds. Lee and co-workers (1995) developed a dynamic headspace procedure for isolating and analyzing the volatiles from oxidized soybean oil, and equations were derived from theoretical considerations that allowed the actual concentration of each flavor component to be calculated. 

AO2. oxidized soybean oil K rate of singlet oxygen formation... 

Moderately thermally oxidized soybean oil (130°C, air flow-through) of peroxide value (PV) = 75 mEq 02/kg diet (compared with the control of 9.5 Eq 02/kg diet) was fed to rats for 40 days (Eder and Kirchgessner, 1999). The study showed no adverse effects on liver, heart, kidney, or adipose tissue FA composition, and even a reduction in the osmotic fragility of erythrocytes and hepatic lipogenesis. However, the moderately oxidized oil slightly reduced the vitamin E status in the tissues. A slightly increased susceptibility of LDL to lipid peroxidation, and an increased concentration of thiobarbituric acid reactive substances (TEARS) in LDL, were also observed. 

Liang, J.H. 1999. Fluorescence due to interactions of oxidizing soybean oil and soy proteins. Food Chem., 66, 103. 

Soybean oil. See Soybean (Glycine soja) oil Soybean oil, blown. See Oxidized soybean oil Soybean oil, epoxidized. See Epoxidized soybean oil... 

Isooctyl alcohol Isophthalic acid, Isopropanolamine, Isostearic acid, Itaconic acid, Jayflex DHP Jayflex DINA Jayflex DIOP Jonrez IC-2805 Kenplast G Lanolin alcohol Maleic acid Maleic anhydride, Mekon White 2-Mercaptoethanol 3-Methoxybutanol Methoxyethanol Methoxyethyl acrylate. Methyl acetyl ricinoleate Methyl caprate. Methyl laurate. Methyl linoleate Methyl oleate Methylpropanediol Neopentyl glycol Nonanolc acid, Nopalcol 4-0 Nomlacresin, Octoxynol 2-Octyi-l-decanol Octyl palmitate. Oleic acid. Oxidized soybean oil Paroll 142 ... 

Oxidized polyethylene, lithium salt. See Lithium oxidized polyethylene Oxidized polypropylene (INCI). See Polypropylene, oxidized Oxidized soybean oil... 

Chlorodiphenyl (54% Cl) Lead Oxidized soybean oil Polybutene Polysulfide Silicone... 

Nonoxynol-9 phosphate Nonyl nonoxynol-7 Octoxynol-4 Octoxynol-13 Octoxynol-70 Oleic amidoethylimidazoline Oleic aminoethylimidazoline Oxidized soybean oil PEG-4 PEG-6... 

Dimethyl cyclohexyl phthalate s-Dioctyl phthalate Glycogen Glycol dilaurate Hydroabietyl alcohol Isooctyl stearate Methyl abietate Methyl hydrogenated rosinate Oxidized soybean oil Tri butyl citrate... 

Corcos Benedetti, R, M. Di Felice, V. Gentili, B. Taghamonte, and G. Tomassi. 1990. Influence of dietary thermally oxidized soybean oil on the oxidative status of rats of different ages. 

Seppanen, C. M., and A. S. Csallany, 2004. Incorporation of the toxic aldehyde 4-hydroxy-2-fra s-nonenal into food fried in thermally oxidized soybean oil. Am 2iLSlS2L 81 1137-1141. 

Figure 5.4. Effect of temperature on the dynamic headspace analyses of volatile compounds in oxidized soybean oil (PV 9.5) (Selke etal., 1987). Courtesy of the Journal of the American Oil Chemists ...

The three GC methods described above were compared in the analysis of volatile compounds in a sample of oxidized soybean oil (Table 5.5). Each... 

Table 5.5. Flavor significance of volatile compounds in oxidized soybean oil (peroxide value 9.5) ...

Kajimoto, G. and Mukai, M. (1970) Toxicity of rancid oil. IX. Digestibility of polymerized fatty acids in thermally oxidized soybean oil. Yukagaku (J. Jpn. Oil Chem. Soc.) 19, 66-71. 

SPME-MS-MVA applications reported to date have used the Varian Saturn ion trap mass spectrometer and 75- J,m Carboxen/PDMS as the SPME fiber (13,14). In one study, for example, SPME-MS-MVA was used to classify various types of food samples according to the level of oxidized off-flavors they contained (14). Mass fragmentation data resulting from the unresolved food volatile components were subjected to MVA. The mass intensities from m/z 50 to m/z 150 were selected to perform MVA. PGA based on SPME-MS-MVA provided rapid differentiation of the following types of samples control soybean oil from oxidized soybean oil that was exposed to fluorescent light for various time periods control nondairy coffee creamer from complaint ( oxidized ) nondairy coffee creamer samples fresh boiled beef from boiled beef with various levels of warmed-over flavor (WOE) and control 2% reduced-fat milk samples from 2% reduced-fat milk samples abused by light or copper exposure. 

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