The glycidol itself is not found in palm or other oils, Roskachestvo told RG. However, in the process of heating (over 180 degrees), both vegetable and animal fats can form glycidyl esters. According to the European Food Safety Authority (EFSA), once ingested, glycidyl esters are likely to be converted to glycidol. However, during the refining/deodorization of palm oil, more glycidyl esters can be formed than in other oils.
A study carried out by the staff of the Federal Research Center for Nutrition and Biotechnology showed that during processing (particularly deodorization) of palm oil, up to 6.29 mg/kg of glycidyl ethers are formed. And, for example, in deodorized sunflower oil, its amount does not exceed 1.19 mg/kg.
However, EFSA reports that between 2010 and 2015, its amount in palm oil has halved, thanks to modernization of oil processing equipment and technology in production. In EU countries, a rule has already been introduced that allows the maximum content of glycidyl ethers in all types of refined and deodorized oils not to exceed 1.0 mg/kg, and for oils used in baby food : 0.5 mg/kg in oils. However, in Russia such an amendment to the technical regulations has not yet been introduced. A draft amendment has now been prepared which foresees limiting the contaminant to a level of up to 1 mg/kg, as in the EU. These standards are expected to be introduced from January 1, 2025.
“Glycidyl ethers are a technological contaminant (pollutant) that forms when exposed to high temperatures during the processing of oils. But not only: it is also formed during frying in a pan. It does not matter what type of oil we use: sunflower, corn, olive; unrefined or refined deodorized, – explained Ekaterina Nesterova, director of technical regulation of the Association of Producers and Consumers of Fat and Oil, – In addition, the pollutant occurs in both vegetable oils and animal fats. Therefore, when frying a piece of meat, we also form glycidyl ethers. They are even in The glycerides of the fat in the flour begin to break down as the bread rests and rises, and will also be converted in part to glycidyl esters during baking.”
However, in oils we can control the amount of said contaminant. Therefore, according to Roskachestvo, most manufacturers have already taken steps to reduce or prevent such contamination. For example, during deodorization, the temperature is lowered, but the treatment time is increased.
However, Roskachestvo notes that it’s still not entirely clear whether glycidyl ethers actually convert to glycidol in the body. Second, there is no final verdict on the dangers of glycidol itself: most studies confirming its carcinogenicity have been carried out in test tubes or rodents, and not in humans. EFSA writes that “there is sufficient evidence for the carcinogenicity and genotoxicity (ability to damage DNA) of glycidol.” But according to the International Agency for Research on Cancer IARC classification, glycidol is classified as group 2A, a probable human carcinogen.
Along with glycidol, monochloropropanediol is also tested for damage, namely 3-monochloropropanediol (3-MCPD), 2-monochloropropanediol (2-MCPD) esters. This is another contaminant that forms under the influence of high temperatures in oils. Roskachestvo explains that it appears when it interacts with chlorine, that is, to form monochloropropanediol in addition to glycidyl ethers, it is enough to salt food during cooking (after all, salt contains chlorine). Therefore, from the point of view of health, it is better to add salt to an almost ready dish.
Due to the peculiarities of obtaining oil from palm fruits, chlorine compounds can remain in palm oil, therefore monochloropropanediol is formed in slightly higher amounts than in other oils. A study conducted by the FRC Nutrition and Biotechnology showed that refined deodorized palm oil contains up to 6.61 mg/kg of 3-MCPD and up to 2.69 mg/kg of 2-MCPD. In sunflower oil, the concentration of 3-MCPD does not exceed 2.47 mg/kg and that of 2-MCPD – 0.67 mg/kg.
“Therefore, it is impossible to call palm oil, like any other refined deodorized oil (it is the one usually used in food production), absolutely safe. But this does not mean that these products are more dangerous and harmful than others: after all, we are more or less eat fried foods, sausages, highly processed, sweet and salty products”, concludes Roskachestvo.
Furthermore, they point out that due to the semi-solid structure, palm oil has replaced hydrogenated fats with a high trans-fat content; its harm has finally been shown, unlike glycidol.
