Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/3/2015
Publication Date: 5/6/2015
Citation: Hwang, H. 2015. NMR spectroscopy for assessment of lipid oxidation during frying [abstract]. American Oil Chemists' Society.
Technical Abstract: Except for total polar compounds (TPC), polymerized triacylglycerols (PTAG) and fatty acid composition, most other current standard methods for lipid oxidation detect very small amounts of oxidation products such as hydroperoxides, conjugated dienes, aldehydes, and epoxides. Therefore, amounts of these products could vary with a slight change in oxidation conditions and controversial results are frequently found due to different experimental conditions. In contrast, 1H NMR spectroscopy method monitors changes in the starting oil molecule and several research groups have already reported that this method is very reliable. We have also conducted the research on 1H NMR spectroscopy and further proved that this method is a very convenient and reliable method to determine the level of oil oxidation during frying. In our study, the triacylglycerol backbone peak was used as a standard peak and relative peak areas of protons located in reactive sites of oil molecules including olefinic, bisallylic and allylic protons were monitored. Strong correlations between the amount of PTAG and losses of olefinic, bisallylic and allylic proton peaks were observed indicating that this method offers highly reliable, non-destructive fast analysis of lipid oxidation. Identification of oxidation products using 1H NMR and 13C NMR will also be discussed.