CHOLESTEROL OXIDATION-PRODUCTS IN SMALL SUN-DRIED FISH

Cholesterol oxidation products (COPs) in small sun-dried fish Spratelloides gracilis and Decapterus maruodsi were extracted, separated by thin-layer chromatography, and then quantified by capillary gas chromatography after trimethylsilylation. Peak identifications were confirmed by mass spectrometry. Four major COPs including 7 alpha- and 7 beta-hydroxycholesterol, 7-ketocholesterol, and 5, 6 alpha-epoxycholesterol, were identified in small sun-dried fish which were stored at ambient temperature for c. 3 months under air. The total concentration of COPs in small sun-dried fsh ranged from 4.82 ppm to 65.7 ppm, with 7 alpha-hydroxycholesterol appearing as the predominant product.