A food colouring is any substance that is added to food to change or enhance its colour. They can be natural or synthetic, being derived from plants, herbs or insects. While some colourings are harmless to most, a few can produce reactions to a minority.
What Are They Used For?
Since we associate colours with certain flavours, manufacturers use these additives to make us associate their colour with the flavour it perceives. They are used in anything, from wine gums to red wine. Sometimes the aim is to simulate a natural colour as perceived by the consumer, such as adding red colouring to glacé cherries (which would otherwise be beige).
Although strict food regulations such as those in UK and EU, and Australia pass these colours as safe for use with food, there is a growing minority that believes the effects of colourings have not been well enough researched and consider their use an unnecessary risk. The US FDA receives compensation for every pound of food dye it certifies (not inspects), which many see as a conflict of interest in regard to the safety of these dyes.
Colour variation in foods throughout season and the effects of processing and storing often make colour addition a commercial advantage to maintain the colour expected or preferred by the consumer. Some of the primary reasons include:
Offsetting colour loss due to light, air, extremes of temperature, moisture, and the storage conditions.
Masking natural variations in colour.
Enhancing naturally occurring colours.
Providing identity to foods.
Protecting flavours and vitamins from damage by light.
Natural food dyes
Not all colours are synthetic. Some of them are very natural indeed, such as the caramel found in Cola fizzy drinks, which is made from caramelized sugar. Chlorella is green, and derived from algae while (get ready for this) Cochineal is a red dye derived from cochineal insects which is also used in cosmetics. Several colourings are derived from plants or herbs, such as Beet juice, turmeric, saffron and paprika.
Potential Health problems
Many colourings have been banned from use in food due to safety concerns, but there still remain some approved colourings that concern some people.
To give a few examples, it is thought that a small percentage (0.01%) of people may be allergic to Tartrazine (coal-tar derivative) and causes hives. Many of the artificial food colourings are suspected to cause reactions ranging from hyperactivity to depression to asthma-like symptoms in sensitive individuals especially children. Norway has banned all products containing coal tar and coal tar derivatives.