What are ‘preservatives’?

We answer a common question on food ingredients.

Preservatives are natural or man-made chemicals that are added to foods to stop them from spoiling. We actually 'preserve' fresh foods ourselves every day, by storing foods in the fridge or freezer. Smoking fish or meats over burning wood or coal are also methods of preservation. Many packaged foods we buy need a preserving agent to keep them from going 'off' and to protect us against food-borne illnesses (food poisoning), which is why these preservatives are used.

Natural preservatives that can be added to foods include salt and sugar. Other preservatives that are commonly used in foods in small amounts include sorbates, which can be identified by the additive numbers 200-203, benzoates (210-218), sulphites (220-228) and propionates (280-283). Some nitrites (249-250) are also classified as preservatives.

How do preservatives work?

To prevent spoilage of foods by moulds, yeast and bacteria, preservatives have an acidic nature that makes the organisms unable to grow in the food.

How can I tell which foods contain preservatives?

All 'additives', including preservatives, must be labelled on food packages. You may commonly see the word 'preservative' followed by its additive number or name. For example, preservative (220) or (sulphur dioxide). This system makes it easy to identify preservatives in foods.

What foods contain preservatives?

You may be surprised at how many foods you commonly eat contain preservatives. Items such as breads, soft drinks, cheese, margarine, wine, dried fruit, processed meats, fruit juice and raw prawns may contain preservatives.

Can preservatives cause reactions in sensitive people?

The body can react to all sorts of natural and artificial chemicals found in the environment and in foods. Particular preservatives may cause reactions in sensitive people, with symptoms including skin rashes and itching, breathing difficulty, sneezing or gastrointestinal upsets.

While some people prefer to avoid preservatives in their diets, all additives used in foods are approved for use by Food Standards Australia and New Zealand  (FSANZ). This process ensures the additives are safe and that they are actually required to serve a purpose in the food, so there are no safety reasons for people to avoid preservatives.

Visit FSANZfor a listing of additive names and numbers.