Abstract
3-Monochloropropane-1,2-diol (3-MCPD) and its esters, which have carcinogenic and genotoxic effects, are contaminants induced by high-temperature that have been detected in refined oils and fatty foods. 3-MCPD esters, chlorinated propanols, were first identified in 1978 in acid-hydrolysed vegetable proteins used as flavour enhancers in many foods. Glycidyl esters (GE) are contaminants that can occur in edible oils during heat treatment and are formed mainly during the deodorisation phase of refining. The International Agency for Research on Cancer has classified 3-MCPD as a 'potential carcinogen for humans' in group 2B. Glycidol has also been classified as group 2A with mutagenic and carcinogenic properties, i.e. 'probably carcinogenic to humans'. In addition, glycidol has been classified by the International Agency for Research on Cancer (IARC) as a 'possible human carcinogen' (group 2A). Toxicological studies have shown that these genotoxic and carcinogenic contaminants induced by heat treatment are released in the gastrointestinal tract and cause the formation of tumours. In this review the mechanisms of formation, toxicological effects of 3-MCPD and GE on human health, and methods of their detection are shown. The latest strategies to mitigate and prevent 3-MCPD and GE formation during crude oil production, refining and beyond are also discussed.