There’s more than one way...
Tom Coultate is the author of 'Food: the Chemistry of its Components'. First published by the Royal Society of Chemistry in 1984, the sixth edition came out in October 2015.
In this article, Tom praises the pragmatism of the UK legislators’ recent approach to the thorny issue of food colour regulation.
Legislators have never found dealing with chemistry easy, especially in the context of food. 1925 saw the UK Parliament’s first attempt at legislation in this field. This followed the widely publicised revelations of, amongst others, Frederick Accum and Arthur Hassall (1820 and 1850s, respectively). They had revealed the widespread use in confectionery of pigments borrowed from the house painters rich in toxic metal compounds.
The 1925 Act established a prohibited list of compounds of antimony, arsenic, lead etc, plus a few dubious vegetable materials, although by this time the synthetic, mostly azo, dyes developed for textiles were being used in food.
Eventually, in 1957, the Colouring Matters in Food Regulations reversed this regulatory approach with a permitted list of some 30 synthetic organic colours and several 'natural' colours such as cochineal, beet pigments and carotenoids.
Over subsequent years the permitted list of synthetic pigments has been whittled down to 12, plus three restricted to particular foodstuffs.
Since the 1970s, UK legislation has been integrated with the EC, and all permitted additives have acquired an E number. This system has served our interests quite well for many years; indeed many legislatures around the world have 'borrowed' European regulations. Safety testing had always concentrated on carcinogenicity but the evolving implication of several food colours in childhood hyperactivity (Attention Deficit Hyperactivity Disorder) was difficult to legislate for.
The research conducted at Southampton University (2007) was insufficiently conclusive to convince EC legislators, but in the UK the FSA still managed to engineer a voluntary ban. Manufacturers eschewing the use of any of the suspect six colours (E102, E104, E110, E122, E124, & E129) were invited to join a public register.
The inevitable result was the rapid disappearance of these colours, not just from children’s sweets and drinks, but from almost all food and drinks in the UK. The EFSA insisted on 'cigarette packet' style warnings on products containing these colours. Ban or no ban it is now almost impossible to find any food products in Europe containing the 'Southampton six'.
The resulting move to 'natural' colours has not been as simple as might be imagined. For example. the anthocyanins – abundant in fruit – work well in the mildly acidic environments of soft drinks and fruit flavoured confectionery, but turn an unappealing dirty greenish blue in the neutral environments of ice cream, blueberry muffins etc.
Cochineal is a wonderfully stable red, but being obtained from insects falls foul of Kosher and Halal rules. Although synthetic blues (E131, E132 & E133) survived they were no longer considered acceptable to the public. However, this was not much of a problem as there are so few naturally blue foods to mimic. However, when Nestlé replaced their blue Smarties® with white ones there was uproar in the social media!
The answer was 'spirulina', extracted from a blue-green alga Arthrospira platensis – not actually an alga at all but a filamentous bacteria.
Its photosynthetic machinery includes the protein C-phycocyanin, which carries a molecule of the bright blue pigment we now know as spirulina. Structurally this resembles bilirubin, a breakdown product of haemoglobin in mammals.
Whole cell preparations of the cultivated microorganism have been marketed as high protein 'health food' for many years, and until recently it was mistakenly used as a 'natural' source of vitamin B12 suitable for vegans.
This long history of human consumption has meant that spirulina’s food colour use has not provoked any safety issues or public outcry. Technically it has proved an excellent colour for confectionery etc. Sadly its regulatory status is proving more problematical.
If it is to be classified as food additive (complete with E number) – alongside the other natural colours, anthocyanins, curcumin, chlorophyll etc – spirulina will have to undergo inevitably time consuming and expensive toxicological scrutiny before its use can be approved, and an E number granted.
The alternative is classification is as a 'colouring food stuff', the best known example being saffron. This valued spice is officially regarded as a flavouring food ingredient that just happens to be coloured. The regulatory fate of spirulina has now been in the EFSA’s in-tray for quite a while but in the meantime the UK authorities are simply turning a blind eye.
It is being left to individual UK local authorities to challenge spirulina’s unregulated use. Any prosecution would have to demonstrate that its use was injurious to health. Unsurprisingly no prosecutions have taken place.