Cholesterol Oxides in Swedish Foods and Food Ingredients: Fresh Eggs and Dehydrated Egg Products

Abstract

ABSTRACT Cholesterol oxides were enriched from lipid extracts of fresh and dehydrated egg yolk products by chromatography on Lipidex and TEAP‐Lipidex. Appropriate fractions from TEAP‐Lipidex were analyzed by capillary GLC as their TMS derivatives. At the detection limit level, ca 0.2 ppm in total lipids, no cholesterol oxides could be detected in fresh egg yolk. Similarly, spray dried egg yolk powder contained only traces of cholesterol oxides when fresh or stored for 2 months at 4°C. Prolonged storage gave lipid extracts which contained variable levels (0.2–12 ppm) of known oxidation products, viz., cholest‐5‐ene‐3β, 7α‐diol, cholest‐5‐ene‐3β, 7β‐diol, 5,6α‐epoxy‐5α‐cholestan‐3β‐ol, 5,6 β‐epoxy‐5 β‐cholestan‐3β‐01, cholest‐5‐ene‐3β, 20α‐diol, 3 β‐hydroxycholest‐5‐en‐7‐one. Traces or small quantifiable amounts of cholest −5‐ene‐3β, 25‐diol and 5α‐cholestane‐3β, 5, 6β‐triol were observed in some samples at longer storage periods.