Sterol oxidation in meat- and fish-based homogenized baby foods containing vegetable oils

Sterol oxidation in commercial meat-based and fish-based homogenized baby foods containing vegetable oil was evaluated. Gas chromatography-coupled with mass-spectrometry (GC-MS) was used for the analytical determination of 7-ketocholesterol and 7-ketositosterol, which were respectively chosen as markers of the sterol oxidation in lipids of animal and vegetable origin. The quantification of cholestanetriol was also achieved, since its negative effects on atherogenesis and other biological processes are well known. In meat-based samples the content of 7-ketocholesterol and 7-ketositosterol were 22-89 and 11-40 g per serving, respectively, while the cholestanetriol amounts were 7-38 g per serving. The 7-ketocholesterol/cholesterol per cent ratio was characteristic of each kind of meat and related to the content of unsaturated fatty acids of animal lipids. In fish based samples the contents of cholestanetriol and 7-ketocholesterol per serving were significantly lower than in meat samples, but fish fillets were about 20-25%, instead of 40 %, of ingredients. The values of the 7-ketocholesterol/cholesterol per cent ratio in fish-based products were close to the values computed for chicken or turkey-based products. The detected values of cholestanetriol showed that the oil addition enhances the development of the indirect bimolecular pathway of cholesterol oxidation, which was even more favoured in fish-based products.