Temperature Dependency When Generating Glycidyl and 3‐MCPD Esters from Diolein

Abstract

AbstractA series of heating tests of pure diolein with and without the addition of tetrabutylammonium chloride as a chloride source were conducted at temperatures that ranged from 180 to 240 °C. The levels of glycidyl ester (GE) and 3‐monochloropropane‐1,2‐diol (3‐MCPD) ester reached plateau levels that depended on the heating temperature. Higher temperatures resulted in higher levels for both esters. A two‐step heating test with a combination of different temperatures revealed that the plateau levels of GE came from steady states between the generation and the transformation of the esters, and was controllable by temperature. Levels of GE were decreased at low temperatures followed by treatment at high temperatures. To the contrary, the plateau levels of 3‐MCPD esters seemed to have originated from the completion of the reactions that were caused by the shortage of an available chloride source and by the stable nature of the esters. The generation of 3‐MCPD esters was difficult to control, since the reactions were completed at an early stage of the heating period. Using raw materials containing low levels of precursor, such as partial acylglycerols and chloride, would be effective in mitigating the formation of the 3‐MCPD esters.