People who consume fried and baked snacks regularly should beware of acrylamide which is a probable carcinogen (cancer-causing substance) commonly found in such food.
In the second test for acrylamide conducted jointly by the Consumer Council and the Centre for Food Safety, one sample of potato chips was found to contain 3,000µg of acrylamide per kg of the snack, the highest level ever detected in food products covered in local studies.
A total of 90 samples over a diverse range of fried and baked snacks were put to the test. With only one exception, all the tested samples - crispy snacks (35), fried and baked potatoes (10), biscuits (39), breakfast cereals (6) - were found to contain varying levels of acrylamide.
In general, food that is rich in carbohydrates, crispy and thin tends to contain a higher level of acrylamide after being cooked at high temperatures.
Higher acrylamide levels were found in some potato chips and a snack type biscuit. Rice crackers were generally found to contain lower amount of acrylamide.
The level of acrylamide in crispy snacks such as potato chips, prawn crackers, corn chips and taro chips ranged from less than 3µg/kg to 3,000µg/kg, while fried potato products such as French fries and baked potatoes were found containing 15µg/kg to 890µg/kg.
For biscuits, the acrylamide level ranged from 32µg/kg to 2,100µg/kg. Breakfast cereals were relatively lower in the acrylamide, from 29µg/kg to 460µg/kg.
Acrylamide is more likely to be formed in carbohydrate-rich food baked or fried at temperatures above 120℃.
In animal testing, it was found that acrylamide increases the incidences of tumors in various organs and tissues like thyroid gland, adrenal gland, mammary gland, testicular tissue and central nervous system, and it is classified as "probably carcinogenic to humans" by the International Agency for Research on Cancer.
Acrylamide in food is formed unintentionally during processing and its level is affected by various conditions. JECFA (Joint FAO/WHO Expert Committee on Food Additives) concludes that it is not possible to make a recommendation on how much of any specific food containing the substance is safe to eat.
The only recommendation they provide is that exposure to acrylamide should be "as low as reasonably achievable". In Hong Kong, as in other countries, there is no specific regulation governing the acrylamide level in food.
From the public health perspective, JECFA is using margin of exposure (MOE) to estimate the risk of acrylamide on human. The lower the MOE, the greater is the public health concern.
The Centre for Food Safety estimated the MOE for acrylamide using test results of this study and the food consumption data of the Hong Kong adult population published by the Centre earlier this year. It was found that, even for the average consumers, the MOE for acrylamide is relatively low and warrants concern.
However, researches showed significant reduction of acrylamide is feasible in certain food products.
In the first joint test conducted in 2006, it was found that the formation of acrylamide in fried taro increased with increasing frying time and temperature. However, coating taro with a thin layer of starch batter before frying could reduce acrylamide formation.
Blanching potatoes before deep frying also helps reduce the level of acrylamide formed.
The food industry is urged to adopt the followings in the interest of consumer health:
- When plant commodities are to be used for high temperature processing, source those species that are less prone to generate acrylamide;
- Use recipes using less acrylamide-prone ingredients;
- Control temperature and duration when frying, roasting or baking of acrylamide-prone ingredients are required.
In any circumstances, when using new methods for food processing, the trade needs to be aware of the possible changes to the nutritional quality or hazards in food.
The Centre for Food Safety has drafted a Trade Guidelines on Reducing Acrylamide in food. Members of the trade are advised to find ways to reduce the acrylamide level in food.
- Consumers, on the other hand, are advised to take the following:
- Do not cook food in an unduly high temperature or for an excessively long period of time.
Adopt a balanced diet with more fruit and vegetables.
Detailed results of the test can be found in the December issue of CHOICE.
The Consumer Council reserves all its right (including copyright) in respect of CHOICE Magazine and Online CHOICE ( https://echoice.consumer.org.hk/ ).