Additives and Preservatives are substances added to food. They can be broadly grouped by their functions as follows:
Preservatives are additives, which extend the storage life of food by stopping germs and mould from spoiling them or making them unsafe. For example, sulphur dioxide — the preservative (220) — is added to some meat products such as sausage meat to prevent microbial growth, and sodium benzoate is added to fruit juices for the same reason.
Antioxidants stops fats and oils from going rancid; for instance, ascorbic acid in butter. Under normal circumstances fats and oils become oxidized when they are exposed to the oxygen in the atmosphere. The process is accompanied by a rancid "off" flavour. If "off" fats and oils are eaten, they can cause sickness. The addition of antioxidants prevents the process of oxidation
Colours make food more colourful; for example tartrazine and sunset yellow.
Emulsifiers and stabilisers mix foods (particularly oils and water) and prevent them from separating; for example Algin (calcium Alginate), derived from native brown seaweed is added to ice creams. Some emulsifiers are plant gums, some are chemicals and others are synthetically produced derivatives of natural products.
Flavour enhancers bring out flavours in foods; well known (& talked about) is monosodium glutamate (MSG)
Nitrates acts as preservatives in some food, but may also be used as a colouring agent. It gives a pink colour to pork.
Anti-caking agent stops powdery foods, such as icing sugar or salt or powdered milk from forming lumps.
Humectants are substances, which absorb water vapour from the atmosphere and prevent the food from drying out and becoming hard and unpalatable. Glycerine is added to royal icing in the home as a humectant, to prevent the icing drying out and hardening
Nutritional Enhancers include vitamins, minerals, soy protein, and milk protein. These are more significant cause for concern that the artificial additives.
Food Additives by Numbers
The Food Standards code requires food labels to list all ingredients in descending order of proportion by weight, except for water, which can be listed last.
The labelling required by law is there to inform consumers about the presence of additives in foods.
Additives are required to be identified by their code number. The numbers used are based on an international system used to identify food additives.
The code numbering system replaces long names on labels but still provides consumers with adequate information about the presence of food additives.
This means, for example, that the substance known as brilliant blue cannot be listed simply as ‘colouring’. The manufacturer of food containing a colouring must use not only the class name ‘colouring’ but also the specific name of the additive: for example ‘Colouring (Brilliant blue FCF)’. To simplify the label, the number for this additive may be used instead of the specific name: for example ‘colouring (133)’
Food labelling allows you to identify the presence of additives in packaged food and to make an informed choice about the foods you buy.
What is the ‘E’ prefix?
Some food labels may list additives with the prefix letter ‘E’. If a food additive number has the prefix letter ‘E’, the European Community has approved it. The additive must still be approved in Food Standards Code to be permitted for use in Australia.
Who Controls the Food Additives?
The use of food additive in foods is regulated by Food Standards Code and enforced in Australia under State and Territory food laws. Foods made in New Zealand may also comply with the provisions of the Food Standards Code.
The Australian and New Zealand Food Authority (ANZFA) is responsible for developing, varying and reviewing food standards for foods available in Australia and New Zealand and for a range of other functions including coordinating national food surveillance and recalls systems, conducting research, assessing policies about imported foods and developing codes of practice with industry
ANZFA is responsible for the development of, or variation to, food standards in the Food Standards Code. The Australia New Zealand Food Standards Council (ANZFSC), made up of State, Territory, Commonwealth and New Zealand Health Ministers, makes the final decision.
Before ANZFA recommends to ANZFSC the use of any new additive in a particular food, it asks these questions:
Is the additive safe to eat (at the requested level in that particular food)?
Are there good technological reasons for the use of the additive?
Will consumers be clearly informed about its presence?
When satisfied with these points ANZFA recommends a maximum level of additive permitted in particular foods, based on technological need and providing it is well within safe limits.
Are Additives Safe?
An additive is authorised for use by ANZFA only if it can be demonstrated that no harmful effects are expected to result from the requested use. This involves an evaluation of data obtained through extensive testing of the additive. A decision on food additive safety is based on acceptable daily intake (ADI), which is the amount of a food additive that can be eaten every day for an entire lifetime without adverse effects.
Adverse Reactions (Intolerance) to Food Additives
Food additives do not cause allergic reactions. Since the reactions are non IgE-mediated they are called food intolerance. Therefore, skin prick test and blood (RAST) is unhelpful in diagnosing these reactions. Like all food intolerances, the only way of diagnosing adverse reactions to food additive is to do Elimination Diets followed by Double-blind Placebo-controlled Food Challenges (DBPCFC).
The lack of agreement about the role of food additives in childhood allergies is fuelled by the paucity of valid objective data. These food additives are the ones most often blamed:
- Artificial colouring has been blamed for numerous childhood ailments from hives to hyperactivity. Although tartrazine is the most notorious additive to provoke asthma, the objective evidence that it can do so in children is weak. Where tartrazine has been shown to provoke asthma, strict avoidance has not shown to be of benefit to the underlying asthma.
Quite often the symptoms are due to the patient’s belief that the additive will provoke symptoms, a food aversion. This conditioned response to food additives is not uncommon.
It is not uncommon for asthmatics to blame a coloured drink for triggering an attack of asthma, when the attack is actually due to the cold temperature of the drink.
- There have been some systematic studies of sulfites in childhood and adult asthma. These studies conclude that sulfites probably provoke asthma more frequently than any other food additives. However, most asthmatics who blame their asthma attacks on sulphites from drinking wines and other sulfite-containing drinks are probably reacting to cigarette smoke in their drinking environment. Foods that may contain sulphites (sulphur dioxide) include: some fruit juices, concentrated soft drinks, wines, beers, dried fruits and pickles.
- MSG is another additive that is often blamed for adverse food reactions, but when it is put to the test with DBPCFC it is a very rare cause of food reactions. I am only aware of one definite case of a patient presenting with a respiratory arrest (from asthma) after drinking wonton soup (which contained MSG) and a DBPCFC confirmed that he was indeed sensitive to MSG.
In conclusion, sulphites are fairly common potential triggers in asthma. The Azo dyes tartrazine and ponceau, the non-Azo dye erythrosine, the benzoate preservatives and MSG are rare potential triggers.
It is important to note that intolerance to additive does not depend on whether the food additive is derived from natural or synthetic source. Far more people are allergic to "natural" foods like peanuts, milk & eggs than to artificial food additives.
The labelling of food products helps people who are sensitive to some food additives to avoid them.