Formation Of 3-Chloropropanol And Glycidyl Esters Under The Deodorization Conditions In Corn Oil

3-chloropropanol-1,2-diol esters(3-MCPDE)and glycidyl esters(GEs)were contaminants in edible oils,which were potentially toxic and endanger human health.In the human body,3-MCPDE and GEs were respectively hydrolyzed into 3-chloropropanol(3-MCPD)and glycidol.3-MCPD and glycidol were classified as 2B and 2A carcinogens by the IARC,respectively.3-MCPDE and GEs were mainly produced in the deodorization stage of refined vegetable oils.The combined action of glycerides and chloride ions could lead to the formation of 3-MCPDE.The precursor material formed by GEs was glycerides.However,there was no uniform conclusion about the influence of glycerides on the formation of3-MCPDE and GEs.And in this process,it was uncertain which way 3-MCPDE and GEs were formed and their intermediates.In addition,the fatty acid(FA)in the oil will also affect the production of 3-MCPDE and GEs.Therefore,it is necessary to study the effects of glycerides and fatty acids on the formation of 3-MCPDE and GEs in the deodorization process,and to infer the formation mechanism according to the law,and then formulate corresponding mitigation measures.In this paper,we studied the effects of glycerides and fatty acid on the content of3-MCPDE and GEs in the n-hexadecane simulated deodorization system and the process of oil deodorization.The results showed that in the simulation system,MAG and DAG could promote the generation of 3-MCPDE and GEs.The effect on the content of 3-MCPDE was:MAG>1,2-DAG>1,3-DAG>TAG.We also found that fatty acid can also promote the production of 3-MCPDE and GEs.The effect of fatty acid on the content of 3-MCPDE was:MAG>1,2-DAG>1,3-DAG>TAG.The effect of fatty acid on the content of GEs was:MAG>1,3-DAG>1,2-DAG>TAG.With the addition of 1%fatty acid system,the effect of glyceride on the content of 3-MCPDE and GEs was the same:MAG>1,3-DAG>1,2-DAG>TAG.In the process of oil deodorization,the addition of MAG and DAG promoted the formation of GEs,and MAG>DAG.Fatty acid promoted the formation of 3-MCPDE and GEs.At the same time,we studied the effects of deodorization conditions(deodorization temperature,deodorization time,and N₂ aeration rate)on the content of 3-MCPDE and GEs in the process of oil deodorization,and the experimental conditions were optimized through orthogonal experiments.The results showed that the optimal experimental conditions were180°C,0.5 h,0.16 Nm³/h,and the production of 3-MCPDE and GEs was the smallest under these conditions.Through FTIR and NMR spectroscopy,we observed the changes of cyclic acyloxonium groups under deodorization conditions.We speculated that MAG,1,2-DAG and 1,3-DAG were the same.First,the alcohol hydroxyl(-OH)and the ester carbonyl react to form a cyclic acyloxonium intermediate.Second,the intermediate was attacked by chloride ions to generate 3-MCPDE and GEs.For TAG,it first removes one molecule of carboxylic acid to form a cyclic acyloxonium intermediate,then this intermediate was attacked by chloride ions to generate 3-MCPDE and GEs.At the same time,we used additives to reduce the production of 3-MCPDE and GEs in the process of oil deodorization.The results showed that additives can inhibit the formation of 3-MCPDE and GEs,and the higher the content of additives,the lower the content of3-MCPDE and GEs.High temperature and long time heating will reduce the inhibitory effect of antioxidants and carbonates on the formation of 3-MCPDE and GEs.The inhibitory ability of additives on 3-MCPDE and GEs was K₂CO₃>TBHQ?Na₂CO₃>Ca(OH)₂>VE.