Food coloring plays a unique role in the world of food ingredients. Unlike most other additives, which are used to enhance the flavor or functionality of the final food product, food coloring is a purely aesthetic ingredient. Based on the old saying “You eat with your eyes,” the goal of food coloring is to simply make food products look more appealing and inviting (though this, in turn, does have the effect of making food taste better, as numerous studies have shown).
To achieve this objective, food manufacturers rely on two broad categories of food coloring: synthetic or artificial, colors, and colors derived from natural sources. Although synthetic colors once dominated the market, natural food coloring is rising in popularity as more consumers seek out clean label products that are free from artificial ingredients. Today, just over half (55%) of the $2.7 billion food coloring market is comprised of natural options. Read on for a look at some of the most common sources of natural food colors.
Betanin—Betanin is a type of water-soluble pigment found in one of the reddest foods around: beets. Betanin can provide a range of shades, from light pink to deep red, and is popular with food manufacturers because it is relatively inexpensive to produce. However, the challenge with betanin is that it is sensitive to light, heat, and oxidation: it usually turns a brownish color if it is cooked or baked, and its reddish tones can fade quickly if the food is stored in transparent packaging and exposed to direct light. For this reason, betanin is most appropriate for frozen or dried foods, or products that have a short shelf life. Some examples of foods that are colored with betanin include ice cream, yogurt, and candy and confectionary.
Anthocyanins—The water-soluble pigment group known as anthocyanins (also called polyphenols) is found in a variety of flowers, fruits, and vegetables including black grapes, cherries, and red cabbage. Anthocyanins are responsible for a range of red, purple, and blue tones, but the shade they display in food products depends on the pH of their environment. In strongly acidic conditions, anthocyanins are at their reddest, but they become more blue in tone as the pH rises. Anthocyanins are most often found in acidic beverages, confections, and jams.
Carminic acid—Carminic acid, or carmine, is a water-soluble pigment derived from a rather unusual source: the female cochineal insect, which is a type of insect native to Mexico and South America. Carminic acid has been used as a dye for a long time and was introduced to Europe by the Aztecs centuries ago. One of its main advantages is that it remains stable when exposed to heat, light, and oxygen. Consequently, it is used in a variety of foods, including alcoholic beverages and processed meats.
Yellow and Orange
Curcumin—Curcumin is the pigment found in turmeric, an increasingly well-known spice (made from the root of the curcuma plant) that is widely used in cookery and is renowned for its health benefits. Curcumin is oil-soluble rather than water-soluble and can fade when exposed to light, but it offers good heat stability. If you’ve ever made a curry with turmeric, you’ll know that this pigment delivers a vibrant yellow shade. Other applications for curcumin include pickles, soups, and confectionary.
Carotenoids—The most popular natural sources of orange and yellow colors are carotenoids, a class of fat-soluble pigments found in plants such as carrots, oranges, saffron, and tomatoes. Fortunately for food manufacturers, these colors are very readily available. Over 400 different carotenoids have so far been identified in fruits and vegetables, and these carotenoids are produced in nature at a rate of 1,000 million tons per year. Heat stable and not sensitive to pH changes, carotenoids are used in foods like margarine, dairy products, and soft drinks.
Riboflavin—Naturally occurring in eggs, milk, and yeast, riboflavin (or vitamin B2) is used for its yellow color as well as for fortification. Riboflavin, which is water-soluble and heat stable, is commonly used in dairy products, cereals, and dessert mixes.
Chlorophylls/Chlorophyllins—The most common natural plant pigment, fat-soluble chlorophyll is present in all green leafy vegetables, particularly in plants like parsley, spinach, and alfalfa grass. However, because chlorophyll itself is highly unstable, food manufacturers also make use of chlorophyllins, which are water-soluble, semi-synthetic derivatives of chlorophyll, and which give the same brightness to dull green tones.
Spirulina—Blue is the most difficult shade for natural color manufacturers to produce, as natural sources of the color blue are extremely limited. One of the only options is spirulina, a blue-green algae that contains the blue pigment known as phycocyanin. Phycocyanin can be derived from spirulina using a simple water extraction process, but the resulting color is very sensitive to acid and heat. As a result, while spirulina can give a bright blue color at a neutral pH, making it a popular choice for products like cake frosting, it can’t be used for soft drinks or anything acidic, as the color will degrade.