Caramel colors are among the oldest food colorings, used in the food industry to impart an appealing appearance to food products since the 1800s. Today, caramel colors account for approximately 80% of all color additives used in foods and beverages, appearing in products such as, spirits, sauces, baked goods, processed meats, and even pet foods.
The popularity of this spectrum of warm, neutral tones in foods is largely attributed to basic psychology: The deep brown colors that develop on cooked steak, or the golden-brown surface of cookies made with eggs, are indications that the food has been converted into a form that is safe to eat. Further, the cooking and baking of foods that yield recognizable brown shades also release a complex array of enticing aroma and flavor compounds.
Caramel colors give consumers many impressions about foods. A subtle use of caramel color can impart a richness to frostings and cream fillings. In baked goods, caramel colors can help enhance the “fresh-baked” appearance of the product. Caramel attributes also can give the impression of “meatiness” in plant-based meat alternatives.
In the US, caramel colors are broadly defined by the Code of Federal Regulations (CFR) as the products of the controlled heat treatment of simple sugars, such as maltose, dextrose (glucose), and sucrose. Historically, CFR-defined caramels, or “true” caramels, have been the most widely used brown colors in the food industry due to the many benefits they offer, including cost effectiveness, versatility, and functional reliability.
In recent years, some caramel colors have come under public scrutiny, especially as consumers become more concerned with the quality and safety of foods. Caramel colors have GRAS status in the United States and are thus exempt from FD&C certification. On a product label, these artificial colors are listed as “Caramel Color” or “Caramel.”
The Food Chemical Codex categorizes CFR-defined caramel colorants into four classes. Class I caramel is made solely with heat treatment and results in a softer golden-brown hue. Class II, III, and IV caramels are made using ammonia and sulfite catalysts that yield products with deeper brown hues. The higher the number class, the darker the shade. Class I caramel colors, sometimes referred to as “plain” caramel colors, have become the fastest growing segment of the category since they meet consumer demand for cleaner labels. However, Class I’s can only attain a light brown shade.
Of particular concern amongst some consumers are Class III and Class IV caramels, which are commonly used in soft drinks. The reaction used to produce Class III and Class IV caramels also yields low concentrations of a chemical byproduct called, 4-methylimidazole (4-MEI). In 2007, the National Toxicology Program (NTP) published the results of a two-year animal study, which suggested that 4-MEI could be associated with an increased rate of lung cancer. Then, in 2011, 4-MEI was identified as a “known carcinogen” on California’s Proposition 65 list of chemicals.
In response, colorant manufacturers have reformulated their products to reduce compounds that concern consumers. Low 4-MeI options are available for Class III and IV caramel colors, and have been proactive in informing clients that 4-MeI is not formed in the manufacture of Class I and Class II caramel colors. For those concerned with sulfites, they note that Class I caramel colors are low in the chemical, as are Class III. Plus, certified organic and project-verified non-GMO versions of these caramel colors are now available.
Under California’s Safe Drinking Water and Toxic Enforcement Act of 1986, food manufacturers using Class III and Class IV caramel colors have been required to include a Proposition-65 warning on the label of the products sold in the state of California. Yet, with the purchasing power of nearly 40 million US consumers, and the site of many global food and beverage production facilities, California’s regulations reach far beyond state lines. This led national brands to explore more natural caramel color alternatives.
Clean is king
In the current food and beverage market, more than 60% of consumers indicate that they desire “100% natural” foods, and that they will take time to examine the label of a product to search for unrecognizable ingredients. Consequently, 80% of new product launches now rely on naturally derived food colorants. And, increasingly, existing products are being reformulated to replace artificial colors with natural ones.
To meet the escalating consumer demand for clean-label food colorants, color manufacturers have been developing an array of “natural browns.” These browns are largely derived from fruit and vegetable products. Also, some innovative color manufacturers are also using non-agricultural methods, such as microbial fermentation, to produce naturally derived pigments on an industrial scale.
There also has been increased development and production of new liquid and powder Class IV non-GMO project verified caramel colors to satisfy growing consumer demands. Although more expensive than mainstream caramel colors, the cost is balanced by the fact that consumers have shown a willingness to pay a premium for non-GMO and organic-certified products.
A Plant-based palette
While there remains no FDA definition for the term “natural,” today, “natural colors” is an industry term that refers to food colors that are derived from naturally occurring sources. Common pigments used as natural food colors include green chlorophyll, blue-green spirulina, red, orange and yellow carotenoids, and blue, red, and purple anthocyanins. Together, these colors provide a full palette of clean-label hues.
In the warm, neutral spectrum of soft yellows to deep browns, naturally derived pigments are extracted from raw materials such as apples, tomatoes, pumpkins, carrots, malt, cacao, and turmeric. The pigments present in these sources possess shades that make it possible to mimic caramel colors in foods.
Specialized extraction and industrial-scale biosynthetic fermentations are the primary ways in which these clean-label food colorants are manufactured. In either case, the resulting food color preparation, which can be in either liquid or powdered form, can be used independently, or may be combined with other natural pigments to produce new hues.
Malted barley flours are another example of a plant-based source of warm brown tones. Malting coupled with natural heating and drying triggers Maillard reactions in the grains and can be controlled at each point to create a range of colors that can be utilized as clean-label alternatives to caramel colors in certain applications.
Malted barley flours can function as “lakes,” meaning they’re not completely water-soluble. The best applications for these pseudo-lakes are items like baked goods or snacks. If a water-soluble color solution is needed, there are specialty malts that can be used for malt extracts that function as natural colorants in beverages. Other grains have been malted to create gluten-free extracts containing reducing sugars that will add color in baked goods or other applications as long as the heat in processing the final product is high enough to create the Maillard reaction.
These non-artificial food color manufacturing techniques offer the benefit of clean-label ingredient names, such as, “fruit juice” or “carrot extract,” for example. Additionally, some pigments can be extracted without the use of any chemical solvents, making them ideal for plant-based and all-natural products.
Aside from the benefit of meeting current consumer needs, naturally derived pigments also offer some functional benefits for product developers. For one, certain pigments, such as carotenoids, are fat-soluble, making them a potentially more favorable color option in fat-based products. While encapsulated, oil-dispersible caramel colors do exist, these value-added versions might not be ideal for a developer working on a clean-label formulation.
Many pigments derived from plants and bioengineered microbial fermentations have antioxidant properties that, in some cases, may provide an added nutritional benefit in certain applications. On the other hand, formulating with naturally derived caramel alternatives also presents some challenges for developers.
Pigments are relatively chemically unstable due to their molecular make-up. Their large, polycyclic structures and plentiful conjugated double bonds are features that allow them to absorb light in the visible spectrum, however these structural attributes also make them very vulnerable to degradation amidst environmental factors such as temperature, pH and light.
“Color stability is certainly a crucial aspect [of product development], especially when it comes to salad dressings, soups, and gravy products,” notes Tamanna Ramesh, MS, CFS, senior scientist in innovation and technology for The Kraft Heinz Co. “The ability of a color to withstand processing is one aspect developers must consider, and the stability to provide an appealing color profile thought the period of shelf life is another challenge,” she adds.
While true caramel colors are incredibly stable and highly reliable under high-heat, and exposed to low pH, and light, naturally derived caramel alternatives require more careful formulation. The correct pigment and preparation, such as powder or liquid, must be carefully selected to ensure that the color functions properly in the food matrix over the desired shelf life. The type of product packaging must also be considered, as some pigments will degrade and lose intensity over time if exposed to light.
Further, formulating with naturally derived caramel alternatives is costly. True caramels are produced with inexpensive raw materials and relatively simplistic technology. Also, naturally derived pigments are sourced via specialized extractions and microbial fermentations that can have much higher input costs.
While caramel colors come in a standard shade range that is predictable and easy to apply to a variety of food matrices, natural colors require more experimentation on the development side. Replacing a Class III caramel in, for example, a meat marinade with a naturally derived caramel alternative could require a high usage rate of the natural color. This could drive up the development cost considerably.
Caramel colors are an invaluable tool for product developers, and consequently, these colors will continue to be used in foods indefinitely. “There is a fine balance between consumers wanting natural food colors and consumers wanting to pay extra for natural food colors,” says Ramesh. “There is certainly a large segment of cost-conscious consumers and “carefree” consumers who do not mind artificial colors in their products,” she explains.
As the consumer perception around caramel colors continues to evolve, food brands and developers will have to weigh functionality and cost to determine the correct color for a given application. Natural caramel colorants are the oldest source of warm and comforting browns, sepias, and golds, but they are no longer standing alone as choices for bringing these comforting colors to foods and beverages.
A Molecular Look at Caramel Colors
Caramelization is a “catch-all” term that describes the decomposition of carbohydrates in the presence of heat. In this relatively basic chemical reaction, simple sugars—such as maltose, sucrose, and dextrose—are hydrolyzed, yielding hundreds of new molecules within a food matrix. Some of these new molecules absorb wavelengths in the brown and yellow portion of the visible light spectrum, giving rise to the recognizable caramel hues. Other molecules formed as the result of caramelization reactions are responsible for complex aromas and dynamic flavors in the transformed food. The visible-light absorbing molecules formed in caramelization reactions polymerize readily, creating large compounds that are highly stable in aqueous solution. This chemical stability is the reason caramel colors have functionalities in foods that can be difficult to match with naturally derived alternatives, which primarily consist of plant-, insect-, or microbially-derived pigments.
Olivia Conrad is a product development scientist and freelance science writer in Boulder, CO, with a degree in Food Science from the University of Maine. She has extensive experience in natural foods product development in categories ranging from frozen desserts to meat snacks. She also is an expert in food safety with a strong working knowledge of FSMA and HACCP principles. She may be contacted at firstname.lastname@example.org or through this magazine.