Sourcing natural colours is no easy feat

Natural colours now make up 31 per cent of the global US$1.15bn per cent colourings market, according to a recent analysis by Leatherhead Food International (LFI). These data belie a shift in the food and beverage industry away from synthetic colours, but it is not as simple as just taking out a synthetic colour and dropping in a natural one.

First of all, a suitable natural source has to be identified that will give the right effect in the product – and that can take some time.

For instance, Nestle Rowntree promised to remove all artificial colourings from its confectionery in 2005 and use natural alternatives instead. However when it came to replacing Brilliant Blue, used in blue Smarties, it was stumped.

While it cast around for a solution, it simply sold white Smarties instead of blue. Then, in February this year, blue was back after Spirulina, from blue-green lake algae, was identified as a source.

A spokesperson for Chr Hansen, which LFI cites as the world’s leading supplier of natural colours, told FoodNavigator.com that in most cases a natural alternative to synthetic colours can be found. But the selection of raw materials and their composition in native pigments and natural stabilizing compounds are critical success factors.

He explained that, as a general rule, natural colours are more sensible to high concentrations of vitamins, minerals, and other active compounds such as quinine and caffeine.

“Especially when talking beverages, the chemical reactivity or the lipophilic nature of natural pigments needs some specific formulation based on emulsion, encapsulation, resistance to oxydation, fading and browning,”​ he said.

Interestingly, however, large food companies are now accepting that they do not necessarily need and exact colour match between the synthetic and the natural colours. This is thought to be because of the consumer desire for natural colours; the branding value over-rides expectations for the precise shade of the food.

Jody Renner-Nantz, food science chemist at DD Williamson Support Center in the US told FoodNavigator.com that regulations also throw up a challenge in natural sourcing.

While DD Williamson does evaluate potential new sources, she pointed out that “novel colour sources must be proven safe for food use before they can be approved as colours for food”.​

Another way of obtaining new natural hues is by blending two or more established natural colours together. Since 2000 DD Williamson has had a partnership with Anaheim, California-based ColorMaker to use this method to deal with novel colour needs.

Supply issues​

Natural sources of colours, and indeed all ingredients, are much more vulnerable to supply issues, such the impact of inclement weather and, in some regions of the world, political instability.

“Natural colours could be more vulnerable to supply issues than synthetic colours. Since natural colours are derived from natural products (fruit, vegetables and other sources), their supply is more susceptible to weather related and shelf life issues than synthetic colours,”​ Jody Renner-Nantz, Food Science Chemist at DD Williamson Support Center in the US told FoodNavigator.com.

For instance, a late frost in 2007 caused damage to elderberry crops in Europe, which had a knock-on effect on crop yield. Although the company has still been able to obtain the material it needed, the shortage has meant it experienced price increases.

In general, DD Williamson looks to assure it can get supply of crucial materials by securing at least two suppliers of raw materials, “ideally from two separate growing areas of the world​”.

A new development announced this month, however, seeks to help out with supply security. ChromaDex has licensed a patented technology to produce antioxidants normally sourced from fruit using fermentation.

Franck Jaksch, CEO, explained that the process allows for the production of anthocyanins, leucoanthocyanins and anthocyanidins – both as classes of compounds and the individual compounds themselves.

Once ChromaDex has found a partner for scale-up and manufacture, these compounds could well be used as food pigments. This is because a slight variance in the pH for each of the individual compounds can yield a different colour.

"You name it - from white to deep purple, and everything in between,"​ said Jaksch. He added that the main basis for the company's interest was to find a "green and sustainable source, and to get away from supply issues" associated with natural colours sourced directly from fruit.​

However as to whether the compounds can be considered natural if not actually fruit derived. "The definition of natural can be tough. The compounds we will manufacture are the same compounds in the natural sources. There is no difference between these compounds structurally."​

Renner-Nantz said that the most exotic or unusual source of natural colours in DD Williamson’s portfolio is carmine, which is extracted from the cochineal insect Dactylopius coccus ​found on particular cacti from the genus Opuntia. Carmine is used as an orange or red food colour.

The cactus typically grows in arid or semi-arid regions of Mexico, South America, India, Iran, parts of Europe and Africa, she said; major suppliers of the insects are located in Peru, Canary Islands and Mexico.

Tomorrow FoodNavigator will investigate the regulatory situation on natural colours in the US and Europe.​