Quality Changes And Evaluations Of Frying Oil During Heated

Several chemical changes undergo during the frying oil heated, inducing varieties of free fatty acid content, peroxide value and the quantity of the polar components. In the experiment the heating effect on the quality of frying oil and polar compounds effect on the animal are evaluated by four parts, including analyzing the indexes of the frying oil during heated process, the polar components analyzed by chromatography, evaluating the mutagenicity of frying oil, studying the effects of frying oil on lipid metabolism and activity of body anti-oxidation.The quality of oil is analyzed by the indexes such as free fatty acid content, peroxide value, and p-aniseed value, the quantity of polar compounds in the frying oil, trans-fatty acid content which are influenced by the chemical changes. When heated for 96 hours, the content of polar compounds in the frying oil is 25%. In the experiment the polar components are isolated by adsorption chromatography using silica columns, and the polar components are divided by two different methods,high-performance size-exclusion chromatography and reversed-phase high- performance liquid chromatography with APCI-MS detection. The polar components are divided into three parts, oxidized diacylglycerols, diacylglycerols, oxidized tricylglycerols.The mutagenicity of frying oil is evaluated by the Ames test and bone marrow micronuclear rates experiment. In the Ames test without S9, for TA100 the relationship of the mutagenicity and content of polar compounds in the frying oil is y=14.992e0.27x, for TA100 the relationships of the mutagenicity and fried frying oil, heated frying oil, polar compounds are y=100.97e0.0736x, y=84.992e0.0936x, y=129.65e0.0567x, there is dose-response relationship in every experiment with S9. The polar compounds in the frying oil make bone marrow micro-nuclear rate higher to 17.44±0.43‰, the relationship is y=3.4553ln(x) +22.979. The polar compounds in the frying oil can induce mutagenicity.Fried frying oil, heated fried frying oil and polar compounds in the frying oil are having influence in lipid metabolism and activity of body anti-oxidation. Heated fried frying oil has disadvantage in assimilation, leading to lower serum triglyceride level to 0.725±0.038mmol/L. The polar compounds in the frying oil and triacylglycerols lead to higher serum cholesterol level, the cholesterol level of the polar compounds highest dose group is 2.94±0.15mmol/L. Frying oil has influence in SOD, MDA, GSH-PX. As the dose increasing the body anti-oxidation regulates, if the dose increasing is out of body anti-oxidation regulation, the body will be attacked by the free radical and the cell will be dandified.