What is a food additive?
A food additive is a substance added to food on purpose, in a small amount, to do a certain job. Sugar and salt are normally counted as ingredients, not additives. Things that enter by mistake are contaminants, not additives.
Additives can be natural (turmeric for yellow, vitamin C) or made in a factory (sodium benzoate). Natural does not always mean safer, and factory-made does not always mean harmful. What matters is the dose and the safety test.
Purposes and uses of food additives
Additives do five main jobs:
- Keep food from spoiling: preservatives slow germs and mould (sodium benzoate, in pickles and drinks); antioxidants stop air from browning fruit or making oils taste bad (vitamin C, vitamin E).
- Make food look good: colours (turmeric, caramel, tartrazine) and bleaching agents.
- Make food taste good: sweeteners (aspartame, stevia) and flavours, and flavour enhancers (MSG).
- Fix the texture: emulsifiers (lecithin) keep oil and water mixed; thickeners and gels (pectin, starch, gelatine) give body; raising agents (baking soda) make cake rise.
- Add nutrition: vitamins and minerals, like iodine in salt or vitamin A in oil.
Standards and labelling of food additives
Safety tests. Experts test an additive on animals and study the results. They find the amount that has no harm, then set the acceptable daily intake (ADI), in mg per kg of body weight, with a big safety gap (often 100 times lower than the no-harm amount).
Standards. A law gives a list of allowed additives and the maximum limit for each food (for example, mg per litre of drink). Using a banned additive, or more than the limit, is illegal. Global guides like Codex Alimentarius, and national bodies like FSSAI (India), set these lists.
Labels. A packet must show: the class (such as colour, preservative), the name or a number (E-number, like E211), and the list of all ingredients in order of weight. Allergy-causing items and added colours must be clear. Some products need a warning, for example for certain colours.
How to read a label: find the ingredient list, look for the class words, check the date, and the licence number. If someone in your family is allergic to something, read every time.
Try it
In the 3D, go to step 5. Tick only the preservative: see the germs go. Untick the antioxidant: see the apple turn brown. Slide the dose above 100 mg/L and watch the warning. At home: read the label on a packet of juice or biscuits. List the classes of additives you can find.
Key formulas and definitions
- Additive = added on purpose, in small amount, for a job
- Dose ≤ legal limit; limit comes from ADI (mg per kg body weight)
- Total allowed per day = ADI × body weight
- Label: class + name or E-number + ingredient list
Worked examples
1. An additive has ADI = 5 mg per kg body weight. What is the most a 40 kg child may take in one day?
5 × 40 = 200 mg per day.
2. A drink may hold at most 100 mg of preservative per litre. A 250 mL glass holds how much at the limit?
250 mL = 0.25 L. 100 × 0.25 = 25 mg.
3. Name the additive class: (a) vitamin C in dried apple, (b) lecithin in mayonnaise, (c) turmeric in rice, (d) sodium benzoate in pickle.
(a) antioxidant, (b) emulsifier, (c) colour, (d) preservative.
4. A packet says "Preservative (E211)". What do the class and number tell you?
The job (preservative) and the exact substance (E211 is sodium benzoate). A buyer can look it up.
5. A factory uses 150 mg of a preservative per litre when the limit is 100 mg/L. What is the problem?
It is 50% over the limit (150 is 1.5 times 100). This breaks the law and may risk health.
Common mistakes
- Thinking natural additives need no limit. Any additive can harm in a large dose.
- Believing all E-numbers are harmful. The number is just a code for a tested additive.
- Mixing up preservative (stops germs) and antioxidant (stops air damage).
- Thinking more additive makes food safer. Extra above the limit is harmful and illegal.