Though baked food products, such as biscuits, cookies, shortbreads and egg rolls, are not a staple in traditional diet of Chinese, consumers eat them as snack or refreshment in daily life. A variety of baked goods sold in the market that is packaged attractively and dazzling is also given as a gift for friends and relatives. However, news medium have reported many times that 3-monochloro-1,2-propanodiol (3-MCPD), glycidol and acrylamide of harmful contaminants were detected in baked food products, like cookies and egg rolls. What exactly are these substances? Why is it produced during the processing of baked food? How much of these substances consumed can cause health impacts? This article describes the chemical backgrounds of above contaminants, i.e., 3-MCPD, glycidol and acrylamide, of which are illustrated the issues associated with food safety and health.
3-Monochloro-1,2-propanodiol (3-MCPD)
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3-Monochloropropanediol Ester (3-MCPDE) is a contaminant formed during the processing of vegetable fats and oils at high temperature (above 200°C). The 3-MCPDE present in baked food products (e.g. cookies) is largely derived from the refined oils in the ingredients; then, it is converted into 3-MCPD in human body.
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The International Agency for Research on Cancer (IARC) classifies 3-MCPD as a Group 2B agent, which is possibly carcinogenic to humans whereas there is insufficient evidence of its carcinogenicity in humans. Reports on animals studies by JECFA indicated that long-term intake of excessive 3-MCPD could damage kidneys function and affect the male reproductive system in animals; but, no genotoxic potential has been demonstrated in vivo of the experimental animals.
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JECFA and European Food Safety Authority (EFSA) have established the Acceptable Daily Intake (ADI) for 3-MCPD and 3-MCPDE, which are 4 µg/kg bw/day and 2 µg/kg bw/day respectively.
Glycidol
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Glycidyl esters (GEs) are contaminants formed at high temperature (above 200°C) during the refining process of vegetable oils. The glycidyl esters present in baked food products (e.g., cookies) are largely derived from the refined oils in the ingredients. They are hydrolysed into glycidol in human body.
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The International Agency for Research on Cancer (IARC) classifies glycidol as a Group 2A agent, which is probably carcinogenic to humans. It is considered as a genotoxic carcinogen in experimental animals but there is insufficient evidence of its carcinogenicity in humans. JECFA also suggests that human exposure to such genotoxic carcinogen should be kept as low as reasonably achievable (ALARA).
Acrylamide
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Acrylamide is usually a contaminant produced at over 120°C high temperature in food processing, such as deep-frying, baking, roasting, toasting and grilling. Studies showed that relatively high level of acrylamide was present in varieties of fried and baked carbohydrate-rich foods. Food cooking with water is unlikely to form acrylamide.
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The International Agency for Research on Cancer (IARC) classifies acrylamide as a Group 2A agent, which is probably carcinogenic to humans. JECFA also suggests that human intake of such carcinogen should be kept as low as reasonably achievable.
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3-MCPD, glycidol and acrylamide are inadvertent contaminants, not food additives. 3-MCPD and glycidol naturally occur during the refining process of edibles oils; whereas, acrylamide is produced in carbohydrate-rich food during high temperature processing. So far, the Codex Alimentarius Commission (CODEX) has not established the maximum limits for these three substances in foodstuffs. In Macao, neither has any legislation to regulate their maximum limits. Since the average consumer does not eat excessive amounts of cookies, biscuits and egg rolls, which are not a staple food, only consumption of them on a daily basis over a prolonged period may pose adverse health effects. At present, there is inadequate evidence for these food contaminants to cause human cancer, so the public does not need to panic.
Moreover, glycidyl esters, glycidol and acrylamide show to be potentially genotoxic in experimental animals but there is limited evidence of their carcinogenicity in humans. It is impossible to fully avoid exposure to these contaminants in daily food consumption. Eating a balanced and varied diet instead of a single food item can help us to stay healthy and reduce the health risks posed by them.
Advice for the Public
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Maintain a balanced and varied diet, and preferably use moist-heat cooking methods, such as steaming and stewing;
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As recommended by the “Healthy Eating Pyramid”, consumers should eat less food enriched of fats or oils;
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While baking oily foods, such as cookies, try to make them turning into golden or bright yellow, and avoid extended baking time.
Further Readings:
002/DIR/DSA/2019
