Food additive means any substance, either natural or synthetic, intentionally added to food for a technological purpose in the processing, packaging, transport or storage of such food. The technological functions of food additive include but not limited to the following –
- Enhancing the safety and quality by the inhibition of microbial growth
- Extending the shelf-life by protection against any oxidative deterioration
- Enhancing the flavour and odour
- Stabilising or retaining the colour
- Improving the texture and consistency of a food, etc
Food additive is not normally consumed as a food by itself and not normally used as a typical ingredient of the food. The term does not include contaminants or substances added to food for maintaining or improving nutritional qualities as well as seasonings such as salts, herbs and spices. There are many types of food additives and the commonly used ones include preservatives, antioxidants, sweeteners, colouring matters, flavour enhancers, thickeners, emulsifiers, etc.
Safety and Public Health Significance
- The toxicity of food additives is generally low. The major food safety concern of food additives is in fact due to their chronic exposure at levels above the safety reference.
- The Joint Food Agriculture Organization / World Health Organization Expert Committee on Food Additives (JECFA) is the international food safety authority responsible for collecting and evaluating scientific data on food additives and allocate a safety reference (i.e. acceptable daily intake (ADI)) to the food additives evaluated. JECFA also makes recommendations on safe levels of use.
- The ADI of a chemical is the estimate of the amount of a substance in food or drinking-water, expressed on a body-weight basis, that can be ingested daily over a lifetime without appreciable health risk. A dietary intake above the ADI does not automatically mean that health is at risk. Transient excursion above the ADI would have no health consequences provided that the average intake over long period is not exceeded as the emphasis of ADI is a lifetime exposure.
- A small proportion of the population may be intolerant to some food additives and may have acute effects, e.g., small amount of sulphur dioxide may cause bronchoconstriction and asthmatic reaction for certain people with allergic conditions.
Advice to the Trade
- When formulating a food product, the food manufacturers are recommended to consider the above "Principles for Using Food Additives" and avoid abuse of food additives.
- Exercise due care in choosing food additives; add only the right type and right amount of food additive which could serve the desired technological function to the food.
- The trade should also take note of the regulatory requirement under the Public Health and Municipal Services Ordinance, Cap. 132, regarding the use and labelling of food additives.
Should there be any doubt on the use and labelling of food additives, seek advice from food scientists or the authority.
The trade may also refer to the website of JECFA for the safety evaluation and specifications of food additives.
Advice to the Public
- Buy foods from reputable sources.
- Read the label of prepackaged food carefully in particular the ingredient list for food additives added (if any) which you could accept.
- People with allergic condition, such as asthma patients, may experience hypersensitive reaction due to some food additives like sulphur dioxide and should be careful in selecting food. Advice from medical professionals may be sought when necessary.
- In choosing foods, avoid as far as practicable those which have abnormal colour, odour and texture; stop consuming the food when it tastes abnormally.
Report any abnormalities of foods to the authority for investigation and other follow-up actions.
Members of the public are advised to take a balanced diet so as to avoid excessive exposure to food additives from a small range of food items.