Chloropropanols and glycidyl fatty acid esters in vegetable oils: occurrence and mitigation strategies

From a nutritional and public health perspective, the inappropriate production and use of vegetable oils is linked to the pathogenesis of several diseases, namely cardiovascular diseases and cancer. Therefore, oils and fats are processed to improve their quality, stability and safety. Despite the removal of a large amount of impurities from the oil, processing can often originate new contaminants that can cause additional health hazards to those who consume these foods. Recently, the European Commission published the new EU legislation, setting the maximum levels of glycidyl esters in vegetable oils and infants’ formulas, besides the established limits for 3-MCPD (3-monocloropropano-1,2-diol) occurrence in soy sauce and hydrolyzed vegetable protein. In this work, a literature review concerning the occurrence of 3-MCPD and glycidyl esters in vegetable oils was performed. Large variations for 3-MCPD content have been observed among oils of different origin, but also in oils of the same kind. Amongst the reviewed data, the highest values were reported for rice bran oil (1449 – 2564 mg/kg) and edible blending oil (1367 mg/kg). For instance, for palm oil, which is the most widely consumed vegetable oil, the values for 3-MCPD ranged from not detected to 540 mg/kg. Concerning glycidyl esters in vegetable oils, frying temperature seems to have a minor impact in its formation than the duration of the frying cycles. According to our knowledge, it is possible to predict the wide distribution of these contaminants in the food chain, due to the considerable high contents of some vegetable oils used not only for frying, but also as ingredients of several processed foods.Therefore, it is of utmost importance to evaluate the presence of chloropropanols and glycidyl esters in vegetable oils. Another gap is the lack of studies on the impact of cooking methods on the amounts of these contaminants.This work was funded by INSA, I.P. under the project “PTranSALT (2012DAN828)” and UID/QUI/50006/2019 with funding from FCT/MCTES through national funds.N/