Natural Food Color: Palette to Palate

One of the reasons why natural is such a powerful-and sometimes misleading-marketing term is that it tends to bring with it associations of simplicity.

Scientists long ago saw through this veneer of straightforwardness, and anyone engaged with the technical issues around natural colors can offer more insights here than most. In the context of colors for food and drink, “synthetics” deliver a fraction of the process and supply chain complexity (not to mention the cost) of today’s “natural” alternatives.

At Sensient Food Colors Europe (Geesthacht, Germany), research and development director Dr. Andreas Klingenberg keeps these challenges in perspective. “There can be stability issues with all kinds of ingredients, no matter if they are natural or synthetic colors, flavors, or other components in a formulation,” he says.

Nature Trails

Even before broaching questions of processing, formulation, and storage, the very term natural is itself fraught with difficulties. Again, definitions of natural are not an issue unique to colors. But where these evolving interpretations do differ, they are often linked to specific food safety, regulatory, and consumer concerns.

For a company such as LycoRed (Ayelsford, UK), which sources reds from tomato-derived lycopene, the complexities of the term natural are conveniently illustrated by another color source, carmine. To start with, whatever degree of “naturalness” it enjoys, carmine’s cochineal origins mean that it is not suitable for vegetarian, vegan, kosher, or halal foods.

Moreover, it is obtained by reacting the raw material with calcium and aluminium. “It may be from a ‘natural’ source, but does this make it ‘natural’ or ‘chemically modified?’” asks Dr. Andrew Kendrick, international technical development manager at LycoRed. The resulting aluminium content is a concern in Europe.

Naturex (Avignon, France) highlights a similar question mark hanging over chlorophyll as a source of green. “You can’t work with chlorophyll itself, but you can with copper chlorophyll,” says business manager Lionel Lesegretain. “This has ‘natural origins,’ but since it goes through a chemical process, is it still ‘natural?’” Legally it is in just as hazy an area. While it can be used in Europe, in the United States it is not on the permitted list.

Of course, as Wild (Berlin) points out, the term natural colors does not actually correspond to any regulatory classification inside the European Union, which defines categories of “coloring foodstuffs” and “colors from natural sources.” “We focus on both, with a little more emphasis on the extracts and concentrates as coloring foodstuffs,” says ingredients product manager Hélène Möller.

Importantly, as she explains, colors “from natural sources” will require an E-number, while foods used for coloring purposes will not. This is an increasingly important consideration for manufacturers.

Sensient has upped the “natural” ante still further with its Cardea range, which is composed of “exclusively natural” ingredients. “No preservatives or chemical additives are used,” says Klingenberg. Instead, the company talks about “interactive natural synergies” which contribute to “superior product performance.”

But to return to the example of reds, for the carmine supply chain, nuanced definitions of natural are the least of its worries. The concerns of the U.S. FDA focus on its apparent allergenicity. “Carmine now needs to be listed on the label, and this is what has tipped the balance there,” says Kendrick at LycoRed. “But the EU is looking at this, too.”

To compound its woes still further, in 2010, the cochineal-carmine sector suffered a significant imbalance between supply and demand, which subsequently impacted cost. “Many smaller players without carmine contracts, which relied on spot-buying, couldn’t supply,” says Kendrick.
 

Three Colors Red

For all its limitations, carmine is “strong and vibrant” and a “fantastic pigment,” Kendrick stresses. In this sense, it may have raised food industry expectations when it comes to those plant-derived reds with more compelling “natural” credentials.

But over recent years, some industry users of these alternative color sources have had the odd nasty surprise. “Of the three main possibilities, beetroot gives a classic strawberry milkshake pink, but it is not heat-stable,” says Kendrick. “In a soft drink, it may suffer oxidative color loss.”

The second category, he says, consists of anthocyanins. “These are less stable than carmine, but more stable than beetroot, and they will give a nice red at low pH,” he explains. But while beetroot will work well in most dairy applications, anthocyanins will tend to turn towards mauve. And some, such as grape skin extract, will turn grey and precipitate-even in milk.

Understandably, LycoRed favors the third option of carotenoids as a source of reds, and specifically the lycopene produced via its own patented process from tomatoes. Traditionally, this source has yielded a more orangey shade of brick-red. “But we’ve worked hard recently to increase the color expression of lycopene,” Kendrick reports. “We’ve brought it much closer to the color of carmine.”

Importantly, the company also says it has made its process more cost-effective. But this still leaves beetroot and then anthocyanins with the lowest cost-in-use, he admits. “And thirdly, carmine and lycopene come in at around the same cost,” he claims. “But of course, none of these is as cost-effective as synthetics.”

Unlike carmine, the lycopene process involves no chemical modification. And carotenoids also have the advantage of being pH-stable and more heat-stable than beetroot. “So, for instance, because anthocyanins brown in the presence of vitamin C, some soft drinks manufacturers want to use lycopene in order to keep their vitamin claim,” says Kendrick.

But carotenoids-lutein, carotene, paprika, or lycopene-have plenty of stability issues of their own, as Naturex points out. “When we use carotenoids in beverages, you can end up with a very difficult matrix when it is exposed to oxygen, light, and heat,” says Lesegretain. “All these factors will affect loss of color.”

One of Naturex’s specialist areas is the stabilization of carotenoid-based colors using natural antioxidants-principally rosemary extract.

“This is one of the most challenging issues, considering all the possible interactions among ingredients,” says Lesegretain. “These critical variables include the flavor oil, the presence of alcohol, high temperature in high brix at low pH, some fruits such as apple and mango, stabilizers, and clouding agents.”

In the area of reds, especially, suppliers have become adept at blending the different color sources, tailoring the blend “to find the best compromise, and the one best adapted to the characteristics of the application,” as Lesegretain puts it.
 

Almost Blue

Blue is also a problem area for researchers into natural colors. “It is no secret that markets are looking for a stable natural blue shade for acidic applications such as beverages,” says Klingenberg.

According to Naturex, the issues with blues are twofold: regulatory and stability. “So in Europe and Asia, spirulina is considered a coloring foodstuff and is used widely, though it is sensitive to heat and acidity,” says Lesegretain. “But in the United States, this option doesn’t exist. It can be used as a protein supplement, but not for coloring purposes.”

He explains this paradox in terms of industry inertia. “Basically, no one has submitted a dossier to the U.S. authorities, presumably because no one wants to invest in order for everyone else to benefit.”

Wild has a fruit-derived blue authorized for use in the United States, says Möller, which is being applied to beverages. For Europe, it now has a blue derived from spirulina used in food applications. It’s capable of producing greens when combined with safflower.

But what is often frustrating for customers, says the company, is the lack of black-and-white answers when it comes to natural color solutions. “Any advice has to be customer-specific and formulation-specific,” says Möller, adding that the final cost equation, too, is likely to be application-dependent.

As Lesegretain at Naturex explains, beyond the regulatory limitations, there are plenty of practical challenges when it comes to blues. “Blue gardenia appears to be light-sensitive, and there are bluish anthocyanins, but these are pH-dependent,” he says. “And spirulina is very heat- and acid-sensitive.”

Like Wild, Naturex has explored its own solutions for filling the blue “gap.” “We are evaluating a new blue color derived from specific anthocyanins,” says Lesegretain. “There are regulatory issues, but we’re almost ready to launch it.”
 

Process and Formulation

The ideal for natural-color suppliers is to be involved in the development and formulation of new products, so that stability and other issues can be factored in at an early stage.

Where an established product is being moved away from synthetics, or from one natural color to another, the many variables that can affect color stability are more likely to be set in stone. But, says Sensient, there are examples of manufacturers redesigning their processes accordingly.

“This is something we’ve seen happening, and we also drive these changes together with our customers,” says Klingenberg. “Very often, small changes to the process, such as reorganizing the addition order within a specific formulation, can lead to improved stability properties.”

Then again, customers are unlikely to make major changes to their manufacturing, or to other ingredients, unless there are long-term cost benefits. “Often there are few opportunities to change the process,” says Möller at Wild. “Generally speaking, color has to work within a given process.”

Not all established products are switching to natural colors, as Leatherhead Food Research explains. “Some companies don’t want to change their product, and decide to ‘tough it out’ with regard to color,” says Dr. Wayne Morley, head of food innovation. “[Others] are prepared to change the formulation, though they may want to recoup the additional costs elsewhere in the recipe.”

Like Möller, he believes that companies are willing to make small changes to their process, but less willing to make any significant capital investment to support natural colors.

Then again, given the hefty premium that manufacturers are already paying for the privilege of using natural-rather than synthetic-colors, perhaps that is not surprising.

This article first appeared in Nutritional Outlook’s sister publication, International Food Ingredients magazine. IFI magazine is the authoritative European publication on the food ingredients market. Visit www.ingredientsnetwork.com.

Sidebar: Learn More about Natural Colors from DSM

For More Insight on natural colors, make your way to the IFT Annual Meeting and Food Expo in Las Vegas in June. On June 27, Michael McBurney, PhD, head of scientific affairs at DSM Nutritional Products (Parsippany, NJ), will chair an expert session on the current regulatory climate, sourcing options, and challenges in formulating with natural and nature-identical colorants. He will be joined by attention deficit hyperactivity disorder (ADHD) specialist James Swanson, PhD, of UC Irvine; Ron Wrolstad, PhD, professor emeritus at Oregon State University; and Pepsi-Cola senior principal scientist Cathy Culver, PhD.

DSM Nutritional Products is the largest global beta-carotene supplier, with manufacturing sites in France, Spain, Switzerland, and the United States.

-Robby Gardner, Associate Editor