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ARS Home » Research » Publications at this Location » Publication #114754
Title: AUTOXIDATION PRODUCTS OF CANOLA OIL AND GENETICALLY MODIFIED CANOLA OIL VARITIES DETERMINED USING LIQUID CHROMATOGRAPHY WITH MASS SPECTROMETRIC DETECTION

Author
item BYRDWELL, W - FLORIDA ATLANTIC UNI
item Neff, William

Submitted to: Journal of Chromatography
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: When fats or oils are heated or stay on the shelf for a long time, they undergo chemical processes that can create undesirable odors or flavors. To know how to make fats more resistant to forming these odors or flavors, it is important to know what chemical compounds are produced by the reactions that take place in the fat or oil. Products formed when fats were aged were identified. This information can be used by food companies to make fats and oils with greater stability during heating, longer shelf lives and better flavor.

Technical Abstract: High stearic, high lauric acid and regular canola oil varieties were heated in the presence of air to allow autoxidation to occur. After the reaction, the oils were analyzed using a non-aqueous reverse-phase high performance liquid chromatographic separation followed by detection using atmospheric pressure chemical ionization mass spectrometry. Oxidized products were separated and identified. The major autoxidation products which remained intact were epoxides and hydroperoxides. Two classes of epoxy triacylglycerols(TAGs) were formed. One class with the epoxy group replacing a site of unsaturation and one class with the epoxy group adjacent to a site of unsaturation as was previously reported for model TAGs. Intact oxidation products resulted mostly from oxidation of oleic acid, while oxidation products of linoleic and linolenic acid chains decomposed to yield chain-shortened species. Both neutral and polar chain- -ened products were observed. Polar chain-shortened decomposition products eluted at very short retention times and required a different chromatographic gradient to separate the molecules. This class of molecules was tentatively identified as core aldehydes. The high stearic acid canola oil yielded more intact oxidation products containing stearic acid, as expected. The high lauric acid oil produced more intact oxidation products which contained lauric acid.