Effect of Oxidation Products and Other Precursors on the Content of 3-McPd Esters and Glycidol Esters in Deodorised Sunflower Oil

Abstract

This paper investigates the effect of precursors on the formation of 3-MCPD esters (3-MCPD-E) and glycidol esters (GE) and discusses ways to reduce the concentration of these toxic esters in deodorised oils. As the content of oxidation products in sunflower oil increases, the amount of MCPD esters formed after deodorisation increases too: from 560 μg/kg (for oil with the peroxide value 1.06 mmol 1/2О/kg and the anisidine value 0.55) to 1290 μg/kg (for oil with PV=6.73 mmol 1/2O/kg and PAV=10.38). Thus, peroxides and aldehydes should be classified as the initiators of the formation of 3-MCPD-E. Accordingly, a way to reduce toxic 3-MCPD-E in deodorised oils is by preventing the formation of oxidation products during the extraction and processing of oils, or by reducing the content of oxidation products in oils before deodorisation. On the contrary, there is no correlation between the content of oxidation products and the amount of glycidol esters in deodorised oil. No relationship has been found between the content of natural antioxidants of oils, tocopherols, and the amount of 3-MCPD-E and GE. Increasing the pH of oils leads to a higher content of 3-MCPD-E resulting from deodorisation. As the number of acid groups increases, the amount of 3-MCPD-E increases too. Conversely, with bigger amounts of acid introduced into the oil, no additional quantities of glycidol esters are formed in the course of deodorisation.