1H-NMR study of cholesterol autooxidation in egg powder and cookies exposed to adverse storage

The level of cholesterol oxides depends on the production and storage conditions for food. We studied the effect of production and storage, heat, and diffuse daylight on spray-dried egg powder and cookies containing large amounts of cholesterol. The cholesterol oxides were isolated by chromatographic procedures, and were identified by recording 1H-NMR spectra of selected HPLC fractions. Autooxidation was quite slow when the sample was stored in a freezer at -20 degrees C. Diffuse daylight increased the amounts of beta-epoxide of cholesterol, whereas heating caused a sharp increase in C-7 oxidized cholesterol derivatives. Extent of cholesterol oxidation depended on storage conditions