Abstract
Tanthu (dánjuan) was fried with soybean oil, and the amounts of cholesterol that migrated into the frying oil from the Tanthu were measured by preparative thin-layer chromatography and gas chromatography. Model experiments on the decomposition of cholesterol in oil and the influence of cholesterol on the deterioration of oil were carried out. Methyl esters of fatty acids and soybean oil (20g) with (0.1% added) or without cholesterol were heated in glass tubes (2.7x20cm) at 180°C. The amounts of unsaponifiable materials and cholesterol in frying oil increased in accordance with the frequency of frying. The degree of decomposition of cholesterol during heating was higher in linoleate than in oleate and soybean oil. Addition of cholesterol had no preventive effect on the deterioration of methyl esters of fatty acids and oil.
