In February last year, Nestle re-introduced the blue Smartie.
The sweet had been withdrawn in 2006, a victim of Nestle's desire to banish synthetic colours from its products. It had to go because no natural blue "of sufficient vibrancy" existed at that time. But consumer demand led the firm to search for one. Within two years, the blue Smartie was back - with great fanfare, and a national advertising campaign - thanks to a natural blue derived from the seaweed Spirulina.
"Consumers are becoming increasingly concerned about artificial colours in food, particularly children's food," says Richard Wood, a member of group technical at Nestle. "By removing artificial colours we take away consumer concerns, and that adds to their enjoyment of our product."
And if it appears that the food technologists were struggling to solve a problem imposed from above, it was quite the opposite.
"Food technologists were among the key drivers of the commitment to remove artificial colours," says Wood. "We could see advances in the field and felt there were enough solutions out there. Blue was always going to be difficult, but other colours are just as difficult depending on the product and the process."
In the two years that the blue Smartie went missing - to be replaced by a white version - Nestle assessed possible natural candidates.
"Spirulina was one of the first options we looked at, but we were working on others in parallel," says Wood. "One of the main challenges was to achieve the same vibrancy with colours from nature. Blue is also a very difficult shade to find in nature."
It could be that the two-year absence worked in Nestlé's favour - because the new version is a pastel shade, a lot paler than the original. Consumers comparing the two side-by-side would have noticed a stark difference.
But by far the hardest problem was to incorporate the new colour into a large scale manufacturing process - and be able to handle the fact that natural colours are not consistent.
"With synthetic colours you use the same process and recipe but just add a different colour dye - so once you had one colour you could expand to an eight-colour range very quickly," says Wood. "With the new colours the process and recipe had to be developed for each one and then, where we could, the final eight were harmonised to make it possible in the factory. Some of the other colours were more difficult to replace than blue."
And it's not just Nestle: other industry giants lined up in 2008 to announce their own efforts to rid their products of artificial colours. In April, Marks & Spencer said it had removed synthetic colours and flavourings from its entire range of food and drink - a three-year process involving over 900 products.
Director of technology David Gregory said: "We've come up against some real challenges on the way. We had difficulty finding a natural colour to replace the vibrant pink filling of Turkish Delight, and now use fruit and vegetable extracts."
At the same time, Cadbury pledged to remove artificial colours from its products "by the end of 2008". A glance at the Food and Drink Federation's website shows a catalogue of quotes from other firms, saying they are removing artificial colours - especially the six named in the infamous 'Southampton study'.
This research, carried out at Southampton University for the Food Standards Agency (FSA), was published in the Lancet in September 2007. It assessed the effect of two 'cocktails' of colours on children and claimed to have found evidence of hyperactivity.
Based on a generally positive reaction to the report, the FSA pushed for a ban at European level. But the European Food Safety Authority (EFSA) was more sceptical. In March 2008, it rejected a Europe-wide ban on the six colours, saying that the Southampton study "provided limited evidence that the mixture of additives tested had a small effect on ... children". It said the study had a "lack of consistency" and should not be used as a basis for altering the acceptable daily intake of the colours.
But despite EFSA's rejection, the six colours are likely to be phased out anyway: at a recent meeting of the European Parliament, ministers voted to ensure that foods using these colours must carry warning labels by 2010. As Food Manufacture reported back in July 2008, this amounted to a 'de facto ban' - as confectioners would rather remove the colour rather than put a warning on their packaging.
Independent regulatory expert Neville Craddock said: "To quote the Parliament rapporteur, no manufacturer will want to say that its products may cause hyperactivity."
Most manufacturers say the Southampton study merely brought the issue to international attention - and that they were already moving away from synthetic colours. In Nestle's case, its decision to ban synthetic colours was made before the study was published.
Statistics confirm the shift towards naturals. According to a 2008 study by Leatherhead Food International (LFI), the 2007 world market for colours was worth $1.15bn - of which 31% was naturals and 40% synthetics. But in the period since 2004, naturals had grown at 5% per annum, and synthetics by 1%.
"We can see that naturals will eventually overtake synthetics - probably in the next five years," says LFI chief executive Paul Berryman. "The key driver is the anti-synthetic colours lobby. Of all additives, colours are the most obviously cosmetic."
Europe is the champion of natural colours and drives their adoption. North America and Asia are still major users of synthetic colours: in North America firms are still demanding exact matches; in Asia, the problem is to do with high ambient temperatures, which are not ideal for the more delicate natural ingredients.
While naturals are on a roll, they have an obvious weakness: they are more difficult to process than synthetics, and are less robust.
"The main challenge relates to shelf-life and stability," says Berryman. "You often need to use slightly more in order to get the same colour, which puts up the price."
Scientists in supplier firms are working on possible answers, such as micro-encapsulation and oxidation protection. In the former, a microscopic 'bubble' protects the colour in the food from light, heat and water activity. It is used in drug delivery, and for probiotics.
"These techniques are more expensive - but will increasingly be used in future," says Berryman.
Ready and willing
It is down to the suppliers of natural colours to develop these new technologies - and most have taken up the challenge willingly.
"Natural colours are now technically very advanced," says Lionel Schmitt, vice president of commercial development in Chr Hansen's colours business. "They are more stable in varying conditions of temperature, light and pH, making it easier for producers to replace synthetic colours with their natural counterparts."
And, he adds, more firms are willing to trade colour performance against a 'cleaner label'.
"Large food manufacturers are accepting that they do not need an exact colour match," he says. "This is thought to be because of the consumer desire for natural colours: the branding value over-rides expectations of the precise shade of the food."
Another critical factor, if naturals are to maintain their growth, is for suppliers to help customers through the implementation - as the colours are not a drop-in solution.
"Every natural colour is sensitive to something," says Andrew Kendrick, international technical development manager at LycoRed. "Manufacturers must recognise that they will have to change their process. "
The options are broad, but they take some expertise to apply. In choosing a natural red, for example, the manufacturer could select a range of products: beetroot (not heat stable); anthocyanin (turns brown with ascorbic acid); carmine (precipitates at low pH.); or lycopene (stable across wide pH- but cloudy).
"In any industrial process you often only have one or two places you can add a colour. Colour companies can help, because they've probably done it before," he says.
The supplier's expertise can be a vital ingredient in making a switch, says Kendrick.
"I once advised a customer who was moving from iron oxide to lycopene," he says. "Iron oxide is very stable, but lycopene fades by oxidation. We had to minimise heat exposure once the lycopene was added. They needed to add colour near the end."
He says, the notion that some replacements are 'impossible' is receding: "The vast majority could switch to naturals as long as they accept a slight shade variation from synthetics - and perhaps a slight price increase."
The real thing
Manufacturers and suppliers are generally tight-lipped when it comes revealing real examples of using natural colours - but a few have been confirmed.
Red: At last year's 'Innovations in Naturals' conference, several examples showed how LycoRed products were being used to colour foodstuffs. These included: Brutal Fruit, an 'alcopop' sold in South Africa; and Ben & Jerry's 'Cherry Garcia' milkshake.
Orange: Two iconic orange-coloured drinks - Coca-Cola's Fanta Orange, and SmithKline's Lucozade - both now use natural colours.
Green: Contrary to popular opinion, lime cordial need not be taken off the shelves - because it can be coloured naturally. Co-Op's own-label cordial uses natural colours, and probably benefits from the fact that it does not look like 'traditional' lime cordial.
Blue: Danish ice-cream manufacturer Polar Is recently switched to Chr Hansen's WSS-P natural blue for its 'Bluetooth' product - which has alternate blue and white stripes. The colour is anthocyanin, which according to Polar, "is extracted from grapeskins"
Key contactsChr Hansen 01488 689800 LFI 01372 376761 Lycored 01622 713700 Nestle 01904 604604