Strategies for the reduction of 3-MCPD esters and related compounds in vegetable oils

For the reduction of 3-monochloro-1,2-propanediol fatty acid esters (3-MCPD esters) and related compounds in edible fats and oils three different strategies are conceivable: removal of critical reactants from the raw material, changing of the refining process or removal of formed 3-MCPD esters and related compounds from the refined product. This paper discusses these possibilities and shows that different raw materials have different capabilities to form 3-MCPD esters and related compounds, whereas palm oil, but also corn oil or coconut oil possess the highest potential for the formation. Washing of the raw material before the refining process with water or ethanol (75%) reduced the capability for the formation of 3-MCPD esters and related compounds in palm oil for about 20 and 25%, respectively. The paper shows that chloride and DAGs seem to be important precursors for the formation of 3-MCPD esters and related compounds. A hypothesis was defined that a content of 4% DAGs could be a threshold for a higher potential of the raw material for the formation of the esters. Using acid solutions (formic acid) instead of water for the generation of strip steam during deodorization resulted in a reduction of the formation of glycidyl esters for about 35%. Practical application: In a first statement the German Federal Institute for Risk Assessment (BfR) but also others recommended to search for alternative techniques for the production of edible oils to ensure lower levels of 3-MCPD esters and related compound. Changing the selection criteria for the raw material, improving the raw material before refining or removal of 3-MCPD esters and related compounds after refining have the advantage that the refining process which has been optimized over the last 100 years regarding oil quality does not need to be changed.