Occurrence of chloropropanols and glycidol esters in foods – A literature review

Thursday, June 15, 2017

Author: Erzsébet Bognár


Keywords: 3-MCPD, refined oils, glycidol esters, chloropropanols, genotoxicity

1. Summary


Chloropropanols and glycidol are transformation products that form during food production, essentially contaminants that form during food processing. Since their production conditions are similar, they are usually mentioned together in the relevant literature, as chloropropanols and related substances. The presence of chloropropanols was first observed in connection with acid-hydrolyzed vegetable proteins, however, they also occur in other foods. They have been detected in fried potatoes, cooking oils, but they also occur in roasted and cooked meats, snacks, biscuits, and practically all thermal-treated products that contain fat.

Based on the toxicological results so far, free glycidol was classified by the International Agency for Research on Cancer (IARC) as probably carcinogenic to humans (2A), and also as genotoxic; free 3-MCPD (3-chloro-1,2-propanediol) was classified as possibly carcinogenic to humans (2B). Currently, regulation in the European Union exist only for free 3-MCPD in soy sauces and acid-hydrolyzed vegetable protein (EC 1881/2006), but many literature sources address the analysis of these compounds in other foods.

Fatty acid esters of chloropropanols form in the high temperature reaction of glycerides (fats, oils) in the presence of chlorine-containing compound – either organic or inorganic. Glycidol esters also form at high temperatures, for their formation diglycerides or monoglycerides need to be present. The formation of the above transformation products in fats and vegetable oils, as well as the reduction of their amounts are important areas of current research.

In this review, I would like to present literature results related to chloropropanols and glycidol, which deal with their occurrence, with special emphasis on cooking oils.


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