When a chef prepares a dish, he/she pays attention to more than just execution of a recipe or cooking process. There is a series of integral and interrelated steps and components—from the selection of ingredients; interaction and timing of the cooking conditions for the ingredients; and the ultimate notebook of flavors, aromas and textures to be incorporated into the finished dish.
Finally, one of the most critical facets is addressed—the dish’s appearance and presentation on the plate. The visual aspect is at work from the beginning of the process.
When it comes to the selection of ingredients, a chef is trained to utilize his or her senses to judge the quality and freshness of the ingredients. Appearance is a key indicator, and color is one of the main considerations. However, while there is some leeway for color differences in a single serving, consistency is critical in a manufacturing setting.
In many cases, the processing of either the raw materials or the finished product can result in loss of the natural and characteristic color of the finished product. This, in turn, can negatively influence the consumer’s perception of the product. Face it: An orange soda with no orange color does not whet a consumer’s appetite for orange soda.
There are two logical approaches to managing these realities. The first is to preserve enough of the natural color of the food through selection of processing conditions and raw materials. The second is to fortify any existing color by the addition of an appropriate coloring additive.
With the recent, overwhelming drive to strip processed products down to their purest, “cleanest” possible form, many of today’s consumers consider adding any color to food as an adulteration. If added color changes consumers’ perceptions of a product’s quality or value—without having any other inherent impact—then the colorant’s presence detracts from consumers’ ability to properly judge the product.
It also is true that the absence of added color can do the same thing: It impairs the consumer’s ability to make a reasoned judgment of the food or beverage’s true quality and flavor.
It’s no secret that the past 20 years have seen substantial changes in the relationship between consumers and the foods they purchase. Labeling laws have increased the amount of nutritional and ingredient information available to consumers. At the same time, the easy availability and flood of nutrition and health information through various media have had a profound impact on shifts and changes in these laws.
Concurrent with—and sometimes driving—these changes has been the dramatic rise in self-appointed experts wielding unprecedented levels of influence on food and labeling laws. As these sources fight to apply their various perspectives on food, nutrition and health to the manufacturing and marketing of products meant for consumption, product developers end up walking through a minefield sown with both real and perceived concerns. Nowhere is this more visible than when it comes to additives, including colorants.
Consumers are left, for the most part, to wade through a torrent of information and make their own decisions about what is credible, useful and relevant. This has led to some intriguing trends in consumer perceptions.
The overwhelming concern over the use of carmine as a colorant is a case in point. Carmine has a long history of effective and safe use as a food colorant. While the source of the color—it is derived from the crushed, dried bodies of cochineal insects—is unusual and perhaps somewhat unconventional, the processing used to isolate and purify the coloring material prior to use should effectively eliminate any concern over safety.
There have been reports of consumers demonstrating sensitivity to carmine, but the number appears to be extremely small. In addition, the FDA has responded by requiring the explicit labeling of carmine where it is used in foods and beverages. While safety of carmine might not be as great an issue as consumers might believe, also driving the clear labeling of the dye was the need for those who are vegetarian and/or keep kosher to know that their foods and beverages were free of such derivatives.
Seeing More Red
As an example of the inextricable nature of color to food production and the tightrope of trends in added colorants, annatto-derived food coloring stands out. Historically, annatto—from the seeds of the achiote plant (Bixa orellana)—has been used for centuries to give some cheeses, such as Cheddar, Colby and other orange cheeses, their characteristic (by modern standards) coloration.
The addition of color to cheese was an early effort to create consistency in appearance and compensate for the seasonal and environmental changes in milk, based on what the animals ate. This was an important characteristic of resultant products, such as butter and cheese. From the chemical side of the equation, when animals are feeding on summer forage (grass, clover, etc.) their milk retains coloring components from the forage, which gives the milk a more yellow hue.
Since these color components are concentrated in the fat fraction of the milk, the cheese-making process concentrates the color further into the cheese. In winter months, when animals feed mostly on hay, the color of the milk becomes whiter, as the coloring components from the grass disappear. As a result, summer Cheddar is naturally more yellow in hue than winter Cheddar. Some consumers began to identify this seasonal variation as a quality issue. The solution: Color the cheese uniformly throughout the year to eliminate any false perception.
Annatto is recognized as being derived from a natural source and, therefore, allows for a cleaner label. (In fact, annatto is a source of the highly bioactive tocotrienol form of vitamin E, but that typically is left behind when the colorant is extracted.)
Ingredient technologists have been studying alternative, naturally sourced coloring materials for use in cheese production. One factor which has complicated this search is that annatto appears to exhibit a uniquely useful behavior in cheese.
Annatto cheese color seems to bind quite effectively to the proteins in cheese curd. This results in less coloration in the whey, something highly desirable for downstream processing of the whey proteins. The other colorants currently under investigation appear less effective in binding to the curd proteins and, therefore, result in a more highly colored whey.
More color in the whey stream means more complicated downstream processing. This also demonstrates that the use of some food colorants is not only peculiar to, but advantageous, for specific applications.
A Burst of Color
Selection of an appropriate color additive begins with an understanding of what is permitted for use in foods by the relevant regulatory standards. These standards are rooted in food safety principles, while taking into account historical patterns of consumption and safe use.
Red yeast rice (Monascus purpureus), for example, is permitted as a colorant for use throughout much of Asia and is based on a long history of common use and local perceptions of food safety. Yet it is not permitted in the US or EU for two reasons: There is no history of use, and there is a concern about safety not shared in the Asian markets where the color is permitted. The safety concerns are based on the ingredient’s content of monacolin K, a natural form of the bioactive chemical found in lovastatin, the prescription-only drug used for lowering cholesterol.
Much of the world has adopted standards for the ingredients that may be used in food, and those standards tend to follow models developed in western Europe, Canada and the US. Where food colorants are concerned, most regulatory systems specify a positive list of coloring materials that are permitted for use.
As long as the colorant fits the definitions on the list, it is permissible. There may be restrictions, such as maximum permitted dosage, but in many cases the only limitation is “consistent with good manufacturing practices.” These lists are not completely harmonized between countries, but there is a great deal of agreement on a global basis. Organizations such as the international Natural Food Colours Assn. (NATCOL) work to harmonize, as much as is possible, the global regulatory system that covers food and beverage colorants.
In the US, regulations governing the use of colorants in foods and beverages are found in the Code of Federal Regulations (CFR), Part 73. Generally speaking, the FDA recognizes two categories of food colorants: those colorants that require certification and those that are exempt from certification.
Those “certified” colorants are denoted as FD&C for “Food, Drug, and Cosmetic.” The list is limited to the following food dyes: FD&C Red #40, FD&C Red #3, FD&C Yellow #5, FD&C Yellow #6, FD&C Blue #1, FD&C Blue #2 and FD&C Green #3. Aluminum lakes of each of these dyes also are permitted, except for FD&C Red #3. Generally, very little FD&C Green #3 is used, because it is easy (and less expensive) to replicate the color using a blend of FD&C Yellow #5 and FD&C Blue #1.
The certification process requires that a representative sample of a batch of food dye be sent to the FDA for assessment. The sample is tested for pure dye content and for a number of residual components of the manufacturing process. If the sample meets the required specifications, then that batch is issued a certification number, which must then be associated with that batch of material through its entire use cycle. This protocol is designed to ensure that the dye meets the current purity standards and is not adulterated.
According to the CFR, when FD&C colorants are present in a formulation, they are to be explicitly declared on the product ingredient declaration. As an example, if a product is colored green with a blend of FD&C Blue #1 and FD&C Yellow #5, the label should declare “Colored with FD&C Yellow #5 and FD&C Blue #1,” or alternatively, “FD&C Yellow #5 and FD&C Blue #1 for Color.”
Developers working on UHT-processed beverages have been interested in finding a replacement for FD&C Red #40 that does not suffer from the limitations of the more commonly used colorants. Some anthocyanin colorants can give the proper color at low pH, but at pH levels above 3.5-5.0, most will turn blue and fade rapidly.
Carmine is very stable under a broad range of pH and heat conditions. However, as previously noted, it cannot be made kosher or vegetarian, which limits its usage. Red beet juice—a common source of natural red—is not sufficiently heat-tolerant to handle high processing temperatures. And, at higher doses, it can contribute earthy, vegetable flavors that can be undesirable.
Lycopene recently has become available for application in beverage systems, but it is relatively expensive on a cost-in-use basis. In situations like these, product developers often will reach for a compromise solution, such as a recently introduced preparation of nature-identical beta-carotene, reported to handle UHT-processing conditions. The color is not a shade match for FD&C Red #40, but the use of beta-carotene allows for a cleaner product label and provides the stability necessary to perform in the application.
The FDA has established a positive list of coloring materials that are exempt from the certification requirement. These coloring materials include familiar items, such as extracts of annatto, turmeric and paprika, as well as beta-carotene. The list also includes vegetable juices, fruit juices and a number of other coloring preparations. While many of the colorants in this category are derived directly from natural sources the FDA does not consider added color to be natural, regardless of the source.
The interpretation requires that, to be natural, the colorant added must be derived from the original material to be “natural” to the food or beverage. While this is the regulatory perspective in the US, most of the food industry routinely refers to this category of colorants as natural.
When these exempt coloring materials are used in a formulation, the source is to be explicitly identified on the label, as well as the function. For instance, if red cabbage coloring is used in a beverage it is to be declared as “colored with red cabbage” or “red cabbage color.”
Alternatively, it is permitted to identify the coloring material by its CFR designation. Red cabbage color could be labeled as “colored with vegetable juice.” Finally, for exempt colorants only, the generic term “color added” is permitted on the label. (The only current exception to this generic label is carmine, which must be explicitly identified.)
Still, sources for natural colorants are trending up, with derivatives of other red vegetables, berries, purple corn, purple potatoes, black carrots, and even leafy green vegetable extracts and beans rushing to fill demand. Such natural colorants, while perhaps not as vivid as artificial, are integral to fulfilling consumer demands for clean labels. This move away from synthetic ingredients, especially artificial food colorants, has been crucial to the rapidly growing clean label trend.
“One of the most important current drivers of colorant trends in the US and EU has been the interest among consumers for cleaner labels and ingredients that appear ‘natural,’” agrees David Reische, PhD, director of research and development/quality assurance of the manufacturing division for H-E-B Grocery Co. “The recent consumer backlash resulted in a more urgent industry response to evaluate the removal of negative-sounding ingredients from product labels.”
Reische notes that, in many product categories, product developers “are now challenged with replacing ingredients with difficult-to-pronounce names from product formulas.” He adds, “Synthetic colors are certainly included in this list of ingredients that are perceived as undesirable, but even naturally-derived colorants such as carmine have also come under fire, due to carmine’s source.”
When to Fake It
While increasing consumer interest in clean labels, without FD&C colorants, has become an important trend, the trend does not necessarily extend over all product categories.
For instance, bakeries and confectioners still rely mainly on FD&C colorants to decorate baked goods and candies, because this is the simplest, most reliable and least expensive way to achieve the color range and presentation their customer base demands.
There also seems to be an impression among consumers that, since candy and sweet baked goods with colored decorations are an indulgence, the synthetic colors are a lesser concern. In other areas, such as yogurt and fresh dairy, natural colorants are used as a means of achieving cleaner labels and greater consumer acceptance.
“In the past, removal of synthetic colors from many foods, while maintaining the established color standard and shelflife, was incredibly difficult,” continues Reische. “Recent advances in the processing and formulation of natural colors, as well as recent additions to the natural color palette, have made it possible to achieve the bright and attractive colors that consumers want in their foods.”
While there are technical challenges, Reische suggests that partnering with knowledgeable suppliers can help shorten the timeframe to completion of the product development cycle.
“A good supplier can provide the correct colorant for the desired outcome in a product with good stability throughout product shelflife, due to a deep understanding of the pH changes, processing temperatures and chemical reactions that occur in processing and storing food,” Reische explains.
When a processor makes the decision to accept the challenge of moving from FD&C colorants to natural ones, the first step is to delineate the practical matters that define the challenge. Synthetic colorants typically are highly soluble in water, and lakes—precipitated soluble dyes with a metal salt component—are readily dispersible in fats and oils.
The advantage of artificial colors are that they offer bright coloration across almost the entire color palette. Moreover, they are available at relatively low cost and in highly concentrated forms. They are easy to use; highly stable in color shade through the entire shelflife of most food products; and are fairly resistant to the effects of most food matrices. And, critically, they are consistent and allow for consistency in product.
Natural food colorants, relatively speaking, represent a greater challenge in application. They are invariably more expensive on a cost-in-use basis. Some, like the anthocyanin-based colorants, are highly soluble in water.
Others, like the carotenoids, tend to be more soluble in oil, although there are exceptions. Ingredient technology has improved many carotenoid colorants, allowing for water-soluble color in vivid ranges of reds, oranges and yellows from such sources as lycopene.
Turmeric color preparations give a bright yellow color quite similar to FD&C Yellow #5 and recently have become highly favored as natural colorants. A significant drawback is that light exposure can destroy the color in application, with only short exposure times.
Some colorants, like caramel and titanium dioxide, are quite concentrated, while others are not—due to limited solubility or other factors that affect the ability to concentrate the coloring principle. Some are sensitive to heat, pH, oxidative stress and, as already mentioned, light. In some cases, there are flavor issues associated with the colorant that derive from the source material.
“The cost-in-use for natural- or plant-derived colorants carries the perception of being a much higher cost in the R&D development cycle, but this is not always true,” says Mike Weber, senior baking scientist at ConAgra Foods Inc.
“The real challenge is stability. Some of the plant-derived ‘all-natural’ colorants vendors are showing to bakery R&D scientists have narrow regions of stability and performance, based on pH sensitivity. This can be a frustration due to the potentially wide pH ranges found in bakery applications. If these products have limited stability in the 6.50-7.50 pH range—typical for cakes, for example—then undesirable fading or shade change can occur,” continues Weber.
Freeze/thaw stability can be another area where challenges arise. “Many large in-store bakeries are moving toward the ‘thaw and sell’ model of bakery products,” says Weber. “It therefore becomes paramount that products developed within these design parameters meet not only a potential six month frozen shelflife, but also maintain stability during unforeseen freeze/thaw cycles. Any colorant used in these types of systems must be able to survive the conditions of use.”
In recent years, color suppliers have moved to address these issues with significant success. New natural colorants have been added to the mix of available options. Advances in the supply of raw materials, processing technology and formulation technology have combined with the development of a better understanding of performance characteristics under different application conditions.
All have contributed to an improvement in the ease of use of natural food colorants. These advances allow food companies to deliver a broader range of products that have cleaner labels by virtue of using naturally derived colorants in place of synthetic ones.
It is possible now to achieve brighter, more vivid coloration across a wider palette of hues. These advances have also contributed to controlling the costs associated with the use of natural colorants. For example, it now is possible to obtain certain dry anthocyanin color preparations up to five times as concentrated as the traditional liquid versions.
These preparations are stable at ambient temperatures for up to five years. And all of these noted advantages mean less expense is tied up in transportation and storage. Such colorants are readily soluble in water and offer vivid colors to a range of products. They find a significant level of use throughout the beverage industry.
In the final assessment, replacing synthetic colorants with naturally derived materials will almost always cost more. However, for many applications, consumer demands for cleaner labels and recognizable ingredients are perceived as outweighing the increased costs.
Given the wide range of striking colors available from nature one may wonder why the list of approved colorants is so short. If the colorant is derived from a known and accepted, edible source that can fit into the currently available regulatory framework, then the process is greatly simplified. However, if the colorant source does not meet these criteria, then the process of acquiring regulatory approval can be time-consuming and expensive.
The approval process in this case requires a petition to the FDA, which includes health and safety data. This type of data can require substantial time and expense to procure. Then, if the petitioner’s application is granted, there may be no exclusive rights to the newly approved colorant, thus very little commercial benefit in pursuing the approval.
In spite of the potentially long and expensive road to approval, new colorants and new production methods are being investigated. There is substantial interest in the production of natural colorants via the use of biotechnology.
There already are products on the market derived from these processes, such as beta-carotene from a salt-tolerant algae and astaxanthin from both algae sources, as well as via yeast-based fermentation, and even from bioengineered bacteria. These cell-culture or fermentation processes are based on harnessing microbial cells or fungi as “miniature factories” designed to produce commercial quantities of colorants.
Other researchers are looking at recovery of anthocyanins from new edible sources, such as black bean and Cornelian cherries. Blue colorant preparations from Spirulina cyanobacteria algae have been recently approved for use in food, and some recent work has suggested that other blue compounds will be obtained from plant, animal, fungal and microbial sources.
Winston Boyd, PhD, is a food industry scientist and consultant and has authored a number of articles on food and ingredient technology. He provides management, technical, regulatory, food safety and business development services to clients in the food and beverage industry and has worked with multiple national and international food and ingredient companies. He can be reached at firstname.lastname@example.org or through Prepared Foods’ staff.
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These Colors Don’t Run
Important as the colors that can be seen are the colors that can’t—that is, the colors that don’t bleed into the rest of the formulation, where a blurry mess isn’t desired. Color migration is ultimately a simple matter of solubility. With the inducement of a proper solvent, colorants will move from an area of higher concentration to one of lower concentration. Typically, and especially in many dairy products and baked goods, this is undesirable.
This was a major hurdle with natural colorants, which are typically water-soluble. Preventing color migration requires an understanding of the systems involved and the resources available. Processors often turned to FD&C lake colorants as a remedy. FD&C Lake colorants are one of the simplest tools to prevent color migration. They are made by creating an insoluble complex of FD&C dye with a metal salt, such as aluminum hydroxide. The resulting product is intensely colored, but water-insoluble particles effectively lock the dye within the particle—so no migration (bleeding) of the dye will occur.
Where natural (exempt) colorants are concerned, the only currently approved lake is carmine, made from the natural dye carminic acid. It is possible to make preparations of natural colorants that rely on similar technology. The natural colorant is applied to a substrate that is not soluble in the final food matrix. Another version of this type of technology is to suspend fine particles of a purified colorant solid into a suitable carrier.
For example, crystalline beta-carotene is hydrophobic. However, it can be milled to optimum particle size—generally 1-5 microns in diameter—in the presence of water and a suitable surface active agent, such as gelatin. As the larger crystals are broken up by the milling process, the gelatin adheres to the fresh surfaces and prevents agglomeration of the finer particles. The gelatin on the surface, combined with the greatly reduced particle size, can render the beta-carotene crystals readily dispersible in water with no settling. This allows for vivid colors that stay in place in the final product.