The fatty acid esters of 3-Monochloropropane-1,2-diol (3-MCPD) in food are unlikely to have major toxic effects on local consumers, according to the findings of a study conducted by the Centre for Food Safety (CFS).
A CFS spokesman said that 3-MCPD was a process contaminant produced naturally in food during food manufacturing, cooking, and other processing activities such as deep frying and roasting. Recent studies revealed that much of 3-MCPD is present in food in the form of fatty acid esters. Thermally processed foods and refined fats and oils were the most significant sources of 3-MCPD fatty acid esters.
There is currently an information gap on 3-MCPD fatty acid esters internationally, including their formation mechanism, analytical method, potential toxicological properties and metabolic pathway such as the degree of hydrolysis during digestion. The primary toxicological concern of 3-MCPD fatty acid esters is the potential release of the toxic 3-MCPD in the body during digestion in the gastrointestinal tract.
"The International Agency for Research on Cancer classified 3-MCPD as a Group 2B agent, i.e. possibly carcinogenic to humans, because there is sufficient evidence showing that 3-MCPD is carcinogenic in experiments on animals, but no data is currently available for the carcinogenicity of 3-MCPD in humans. However, 3-MCPD would affect the kidney, the central nervous system and the male reproductive system of rats," the spokesman said.
In 2010, the Codex Committee on Contaminants in Foods (CCCF) included 3-MCPD fatty acid esters in the priority list for evaluation by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) for toxicological assessment and exposure assessment. There is currently a lack of data about 3-MCPD fatty acid esters in foodstuffs internationally. The CFS, as a World Health Organization (WHO) Collaborating Centre for Risk Analysis of Chemicals in Food, conducted this study between 2011 and 2012 with a view to giving the WHO an overview of the levels of 3-MCPD fatty acid esters in various local foods and assessing the potential health risk posed to local consumers.
The study focused on food items reported to have higher levels of 3-MCPD fatty acid esters. A total of 300 food samples were collected in the study. Results revealed that the levels of 3-MCPD fatty acid esters were higher in the food groups "Biscuits", "Fats and oils", "Snacks" and Chinese pastry" with mean levels of 440, 390, 270 and 270 £gg/kg respectively.
The CFS also estimated the dietary exposure of local citizens to 3-MCPD fatty acid esters using the food consumption data from the Hong Kong Population-based Food Consumption Survey 2005-2007. The results showed that the dietary exposures to 3-MCPD fatty acid esters for "average" and "high" adult consumers were 0.20 £gg/kg body weight/day and 0.53 £gg/kg body weight/day respectively.
"The JECFA established a provisional maximum tolerable daily intake (PMTDI) of 2 £gg/kg body weight /day for 3-MCPD. Assuming that 100 per cent of the toxic 3-MCPD was released from its fatty acid esters by hydrolysis in the digestive system, the dietary exposures to 3-MCPD for average and high adult consumers were only 10 per cent and 26 per cent of the PMTDI respectively, which were way below the PMTDI," the spokesman said.
He added that by virtue of the dietary exposure to 3-MCPD fatty acid esters in adults alone, the findings of the current study did not provide sufficient justification to warrant changes to the basic dietary advice on healthy eating. Members of the public are recommended to maintain a balanced and varied diet which includes a wide variety of fruits and vegetables. However, since refined oil is reported as one of the major sources of 3-MCPD fatty acid esters, consumers may reduce their consumption of fats and oils to reduce the exposure to 3-MCPD fatty acid esters.
As for the food trade, they are advised to find ways to reduce the levels of 3-MCPD fatty acid esters in refined fats and oils while not impairing the quality of their products.
Details of the study are available on the CFS website: www.cfs.gov.hk.
Ends/Wednesday, November 7, 2012
Issued at HKT 14:31