Food Additives
Key facts:
- Food additives are substances added to foods to perform specific functions. Additives may be natural, nature identical or artificial.
- The main groups of food additives are antioxidants, colours, flavour enhancers, sweeteners, emulsifiers and stabilizers and preservatives.
- All additives are thoroughly assessed for safety before they are allowed to be used. Approved additives are given a number and some are also given an ‘E’ if they been accepted for safe use within the European Union.
- Natural additives are substances found naturally in a foodstuff and are extracted from one food to be used in another. For example, beetroot juice with its bright purple colour can be used to colour other foods such as sweets.
- Nature identical additives are man-made copies of substances that occur naturally. For example, benzoic acid is a substance that is found in nature but is also made synthetically and used as a preservative.
- Artificial additives are not naturally present in foods and are made synthetically. An example is azodicarbonamide, a flour improver that is used to help bread dough hold together.
Why are they used?
Additives are used for a range of functions including:
- To maintain the nutrient composition of the food and to keep it safe to eat
- To make food look or taste better
- To extend the shelf and storage life of a food product
- To improve the nutritional composition of a product (e.g. increase the vitamin content e.g. by adding ascorbic acid)
- Aiding in the processing and manufacture (e.g. emulsifiers, to help mix together ingredients).
Food additives and function:
Food additives are normally grouped by their function. The main groups of food additives are described below:
Antioxidants – decreases the chance of oils and fats in foods from combining with oxygen and changing colour or turning rancid. Rancid fats smell and taste unpleasant and are a health risk. Antioxidants are also used in fruits, vegetables and juice to extend the shelf life. Vitamin C (ascorbic acid) is one of the most widely used antioxidants (link to vitamin C).
Colours – are used to make food look more appetizing. During the processing of some food, colour can be lost so additives are used to restore the original colour, for example canned marrow fat peas. Colour additives can also be used to make the existing food colour brighter, for example, enhance the yellowness of custard. Colours are either natural (e.g. curcumin (E100) is a yellow extract of turmeric roots), nature identical or artificial. Some colours are also vitamins (e.g. riboflavin and beta-carotene) and these are the only colours allowed in baby food.
Flavour enhancers – are used widely in savoury foods to enhance the existing flavour in the food. Monosodium glutamate is an example of a flavour enhancer.
Sweeteners – are either intense or bulk. Intense sweeteners (for example saccharin and aspartame) are many times sweeter than sugar and so are only used in tiny amounts. This makes them suitable for use in products such as diet drinks, which are very low in energy. Bulk sweeteners (such as sorbitol and sucralose) have a similar sweetness to sugar so are used in similar amounts to sugar in foods.
Preservatives – are used to help keep food safe to eat for longer. Any processed food with a long shelf-life is likely to include preservatives, unless another way of preservation has been used, such as freezing, canning or drying. Traditional methods using sugar, salt and vinegar are still used to preserve some foods.
Emulsifiers, stabilizers, gelling agents and thickeners – emulsifiers help mix together ingredients like oil and water that would normally separate; stabilisers prevent them from separating again. They are used in foods such as ice-cream. Gelling agents are used to give foods a gel-like consistency, while thickeners increase the viscosity of foods.
Evaluating the health risk of food additives:
Risk assessment of food additives are conducted by an independent, international expert scientific group – the Joint FAO/WHO Expert Committee on Food Additives (JECFA).
Only food additives that have undergone a JECFA safety assessment, and are found not to present an appreciable health risk to consumers, can be used. This applies whether food additives come from a natural source or they are synthetic. National authorities, either based on the JECFA assessment or a national assessment, can then authorize the use of food additives at specified levels for specific foods.
JECFA evaluations are based on scientific reviews of all available biochemical, toxicological, and other relevant data on a given additive – mandatory tests in animals, research studies and observations in humans are considered. The toxicological tests required by JECFA include acute, short-term, and long-term studies that determine how the food additive is absorbed, distributed, and excreted, and possible harmful effects of the additive or its by-products at certain exposure levels.
The starting point for determining whether a food additive can be used without having harmful effects is to establish the acceptable daily intake (ADI). The ADI is an estimate of the amount of an additive in food or drinking water that can be safely consumed daily over a lifetime without adverse health effects.
International standards for the safe use of food additives:
The safety assessments completed by JECFA are used by the joint intergovernmental food standard-setting body of FAO and WHO, the Codex Alimentarius Commission, to establish levels for maximum use of additives in food and drinks. Codex standards are the reference for national standards for consumer protection, and for the international trade in food, so that consumers everywhere can be confident that the food they eat meets the agreed standards for safety and quality, no matter where it was produced.
Once a food additive has been found to be safe for use by JECFA and maximum use levels have been established in the Codex General Standard for Food Additives, national food regulations need to be implemented permitting the actual use of a food additive.
How are they controlled?
All additives are thoroughly assessed for safety before they are permitted for use, and they are only then permitted to be used in a limited range of products and in certain amounts. These amounts are based on an Acceptable Daily Intake (ADI) calculated by the European Food Safety Authority (EFSA) from the results of safety tests. The ADI represents an amount that can be ingested daily over a lifetime without appreciable health risk. Approved additives are given a number and some are also awarded an ‘E’. An E shows the additive has been accepted as safe for use within the European Union. Even when an additive has been approved, regular repeat testing is required to maintain its status as ‘approved’. Food labels give information about most additives present in the ingredients list, so that consumers can make informed choices.
How do I know which additives are in my food?
The Codex Alimentarius Commission also establishes standards and guidelines on food labelling. These standards are implemented in most countries, and food manufacturers are obliged to indicate which additives are in their products. In the European Union, for example, there is legislation governing labelling of food additives according to a set of pre-defined “E-numbers”. People who have allergies or sensitivities to certain food additives should check labels carefully.
WHO encourages national authorities to monitor and ensure that food additives in food and drinks produced in their countries comply with permitted uses, conditions and legislation. National authorities should oversee the food business, which carries the primary responsibility for ensuring that the use of a food additive is safe and complies with legislation.
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