Cholesterol Oxidation Products in Some Muscle Foods

Abstract
Cholesterol oxidation products were estimated in some meat products by capillary gas chromatography after trimethylsilylation. Peak identities were confirmed by mass spectrometry. Freeze‐dried pork, stored in contact with air at 22°C for ca. 3 yr, revealed 7α‐ and 7β‐hydroxycholesterol, 7‐ketocholesterol, α‐ and β‐epoxide and cholestane‐triol. The total concentration of oxidation products reached almost half of the remaining cholesterol content with 7‐ketocholesterol as the predominant species. Some oxidation products were noted at a few ppm levels in broiled beef steaks, but not in precooked beef products. As rancidity development advanced in comminuted and cooked meats during storage, the oxidation of cholesterol became apparent.