Further Investigation of Oxidized Cholesterol Derivatives in Heated Fats

The oxidation of cholesterol in tallow heated at various frying temperatures, 135°, 150°, 165°, and 180°C was studied by capillary gas chromatography. The linearity of formation of 7‐ketocholesterol with heating time was confirmed. However, no significant differences in rate of formation of 7‐ketocholesterol were noted among temperatures of 135°, 150°, and 165°C. Therefore, it was not possible to construct a kinetic equation. The possible efficacy of antioxidants at frying temperatures was demonstrated by incorporating ascorbyl palmitate plus dl‐α‐tocopherol into tallow at 135°C.