Sanitary evaluation of frying fats: A new method based on thin-layer chromatography and colorimetry



The level of oxidized compounds can be taken as an indicator of the sanitary quality of frying fats. The determination of oxidized fatty acids (insoluble in petroleum ether) is time consuming and not very accurate. In this paper a new method is reported, based on thin-layer chromatographic separation of oxidized triglycerides and colorimetry after reaction with vanillin. The method is accurate (C.V. = ± 3.82%), economic, not time consuming and requires only a very small amount of fat.