Food colours are additives used to colour foodstuffs. These substances serve to restore the original appearance of a food product if its colour has been affected by processing, storage, packaging or distribution, whereby visual acceptability may have been impaired. It also serves to make food more visually appealing or give colour to food otherwise colourless.
Colour is a significant criterion in sensory food evaluations. Certain “colour codes” are universal and understood by everybody. This makes food colourings a means of sales promotion in the food industry. However, there are also foodstuffs for which the addition of colour is prohibited by law, such as fish and meat, beer, spices, tinned mushrooms, potato products, chocolates or dried fruit.
According to Regulation (EC) No. 1331/2008 of the European Parliament and of the Council, all food additives must undergo a safety evaluation by the EFSA before the EU risk managers decide about their approval. The 40 currently approved food colours are listed in Annex II Part B of Regulation (EC) No. 1333/2008.
Azo colours are synthetic food dyes. Except for very few of them (6 substances shown below), azo colours are considered to cause cancer and be mutagenic, hence putting consumers at risk. For this reason they have not been approved as food additives. However, some azo colours that have been banned in the European Union, e.g. Sudan colours, are used in a number of countries to intensify the colour of paprika or chilli powder or to compensate for colour loss caused by light or ageing.
EU-approved azo colours with a warning:
Products containing any of the colours listed below require labelling with the warning “May have an adverse effect on activity and attention in children”:
- Tartrazine (E 102)
- Carmoisine (E 122)
- Quinoline yellow WS (E 104)
- Ponceau 4R (E 124)
- Sunset Yellow FCR (E 110)
- Allura Red AC (E 129)
This warning was specified as a precaution by the EU in Annex V of Regulation (EC) 1333/2008 although what is known as the Southampton Study (McCann et al. 2007) did not show clear evidence of the assumed link between the consumption of these food colours and the behaviour of children.
At ifp Institut für Produktqualität food colours are determined by means of thin-layer chromatography, yet preferably by means of HPLC (high-performance liquid chromatography).