Food Safety Focus (10th Issue, May 2007) – Food Safety Platform
Food Additives: Safety and Hazards
Reported by Mr. Arthur YAU, Scientific Officer
Risk Communication Section, Centre for Food Safety
Everyday, we benefit from the safety, quality and convenience brought to us by food additives. Starting from breakfast in the morning, the oil we use to fry our scrambled eggs may contain antioxidants, so that it would not turn rancid easily; the table salt we add contains anti-caking agent, so that it would still flow freely even when the humidity is high; the high-calcium milk we drink contains emulsifier, so that the milk fat would not separate; the bread contains raising agent, so that it is spongy. Food additives become an indispensable part of modern day life.
Illustration: Food additives are used in many prepackaged food
Safety of Food Additives Used In Hong Kong
Food additives that are allowed to be used in Hong Kong are safe. The Centre for Food Safety (CFS) has made reference to the evaluations and recommendations of international authorities like the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the Codex Alimentarius Commission (Codex) when establishing safety and regulatory controls over food additives. JECFA evaluates the safety of food additives based on long term exposure before it makes recommendations. Then Codex, the international food safety authority, recommends specific legal regulatory levels for food additives that may be used in certain types of food. On the other hand, food manufacturers should practice Good Manufacturing Practice and apply food additives in a way that only the minimum amount is added to achieve the desired technological effect.
However, despite the long history of safe use for many food additives, it is well known that certain food additives may cause health concerns in certain groups of people.
Special Groups, Special Additives Requiring Special Attention
Sulphites, and its related compound sulphur dioxide, are additives commonly used in wines, dried vegetables and fruit products. Despite their long history of safe use to most people, sulphites do pose hazard to people who are allergic to them and may lead to asthma attack in this group of persons.
Aspartame is an artificial sweetener which is produced from amino acids, the building blocks of proteins. This popular low calorie sweetener is often found in products like soft drinks and chewing gums. However, people who suffer from the rare genetic disease phenylketonuria (PKU) cannot properly metabolise phenylalanine, a breakdown product of aspartame, while the general population can enjoy the low calorie sweetener without such problem. Therefore, people with PKU should restrict phenylalanine from all sources, including aspartame and high-protein foods.
Nitrates and nitrites are often added to cured meat products like ham and sausages as preservatives because of their effectiveness against Clostridium botulinum and their ability to impart the characteristic reddish-pink colour. However, large dose of the additives may cause methaemoglobinaemia, a disease of the blood characterised by breathlessness and bluish discolouration of skin. Therefore, the usage level should be restricted.
How to Make a Discerning Choice?
While food additives and modern food technology bring about convenient and safe foods to the consumers, people who suffer from the above mentioned conditions or wish to avoid intake of certain food additives should read the food labels carefully before consuming prepackaged foods. For example, PKU patients should look out for "Sweetener (Aspartame)" or "Sweetener (951)" when purchasing prepackaged foods. The general public should maintain a balanced diet to avoid excessive exposure to additives from a small range of food items.
From 10 July 2007, all prepackaged foods sold in Hong Kong will be required to include the functional classes of food additives and their names or identifi cation numbers in the ingredient list. In order to maximise the benefits to the consumers, the CFS has prepared a booklet entitled "The Consumer Guide to Food Additives" to help consumers identify food additives when purchasing prepackaged food. The Guide is available for free at Health Education Exhibition and Resource Centre, Communication Resource Unit and all district offices of the Food and Environmental Hygiene Department. It is also available for downloading from the CFS website.
Illustration: "The Consumer Guide to Food Additives"