Caramel color or caramel coloring is a soluble food coloring. It is made by a carefully controlled heat treatment of carbohydrates, in general in the presence of acids, alkalis, or salts, in a process called caramelization. It is more fully oxidized than caramel candy and has an odor of burnt sugar and a somewhat bitter taste. Its color ranges from pale yellow to amber to dark brown (see Color, below).
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Caramel color is one of the oldest and most widely-used food colorings, and is found in almost every kind of industrially produced food, including: batters, beer, brown bread, buns, chocolate, cookies, cough drops, dark liquor such as brandy, rum, and whisky, chocolate-flavored flour-based confectionery, coatings, custards, decorations, fillings and toppings, potato chips, dessert mixes, doughnuts, fish and shellfish spreads, frozen desserts, fruit preserves, glucose tablets, gravy browning, ice cream, pickles, sauces and dressings, soft drinks (especially colas), sweets, vinegar, and wines. It is approved for use as a food additive in the EU,[1] Australia, New Zealand,[2] and USA.
Caramel color is made by controlled heat treatment of carbohydrates (nutritive sweeteners, which are the monomers glucose and fructose or their polymers, e.g., glucose syrups, sucrose, invert syrups, and dextrose), in general in the presence of food-grade acids, alkalis, and salts, in a process called caramelization. Antifoaming agents may be used as processing aids during manufacture. Unlike caramel candy, it requires close to maximum oxidation of the sugar to produce a caramel concentrate that has an odor of burnt sugar and a somewhat bitter taste in its raw liquid form. Its color ranges from pale-yellow to amber to dark-brown.
Caramel color molecules carry either a positive or a negative charge depending upon the reactants used in their manufacture. Problems such as precipitation, flocculation, or migration can be eliminated with the use of a properly charged caramel color for the intended application. A crude form of caramel color can be made by strongly heating sucrose.
Internationally, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) recognizes four classes of caramel color, differing by intended application and in the reactants used in their manufacture, each with its own INS and E number, listed in the table below.
| Class | INS No. | E Number | Description | Restrictions on preparation | Used in |
|---|---|---|---|---|---|
| I | 150a | E150a | Plain caramel, caustic caramel, spirit caramel | No ammonium or sulfite compounds can be used | Whiskey among many |
| II | 150b | E150b | Caustic sulfite caramel | In the presence of sulfite compounds but no ammonium compounds can be used | |
| III | 150c | E150c | Ammonia caramel, baker's caramel, confectioner's caramel, beer caramel | In the presence of ammonium compounds but no sulfite compounds can be used | Beer, synthetic soy sauce, and confectionery |
| IV | 150d | E150d | Sulfite ammonia caramel, acid-proof caramel, soft-drink caramel | In the presence of both sulfite and ammonium compounds | Acidic environments such as soft drinks |
Color strength (Tinctorial Power) is defined as the absorbance of a 0.1% solution (weight/volume) in water, measured using a 1 cm light path at a wavelength of 560 nanometers.[3]
The color tone of the caramel color is also important. This is defined by the Linner Hue Index, which is the measure of the color hue or red characteristics of the caramel color. It is a function of the absorbance of light of wavelengths 510 and 610 nm. In general, the higher the Tinctorial Power, KO.56, the lower the Hue Index and the lower the red tones.[4]
Various other indices are in use around the world and there are conversion factors between them.[5][6]
Caramel color is a colloid. Although the primary function of caramel color is for coloring, it also serves additional functions. In soft drinks, it functions as an emulsifier to help retard the formation of certain types of "floc" and its light protective quality can aid in preventing oxidation of the flavoring components in bottled beverages.
Internationally, JECFA has set the Acceptable Daily Intake (ADI) of Class I caramel color as "not specified"; that of Class II as 0-160 mg/kg body weight; that of Class III as 0-200 mg/kg body weight; and that of Class IV as 0-200 mg/kg body weight.
The United States Food and Drug Administration classifies and regulates caramel color in 21 CFR 73.85 (PDF) as a color additive exempt from certification. Unless a food has a standard of identity, caramel color may be safely used in foods generally at levels consistent with good manufacturing practice.
The International Programme on Chemical Safety (IPCS) has concluded that commercially-produced caramel color has the same toxicological properties as caramel produced by cooking or heating sucrose, except for those prepared using ammonium (Class III and IV). The IPCS has not concluded that caramel color exhibits carcinogenicity or mutagenicity, based on its studies.[7] However, the IPCS status report for the product includes says that "Side-effects are manifested from the use of E150c and E150d, where intestinal problems may occur after ingestion of large amounts. Due to the complex nature of the mixtures, toxicology tests are still being carried out." California now lists one of its constituent chemicals in the state's list of chemicals known to the state to cause "cancer, birth defects or other reproductive harm".[8]
Caramel color has excellent microbiological stability. Since it is manufactured under very high temperature, high acidity, high pressure, and high specific gravity, it is essentially sterile as it will not support microbial growth unless in a dilute solution.
When reacted with sulfites, caramel color may retain traces of sulfite after processing. However, in finished food products, labeling is usually required only for sulfite levels above 10 ppm.
Caramel coloring may be derived from a variety of source products that are themselves common allergens, such as lactose (from milk), dextrose (usually derived from corn), starch hydrolysates (from corn or wheat), or malt syrup (in general derived from barley). As such, persons with known sensitivities or allergies to food products are advised to avoid foods including generic caramel coloring or first determine the source for the caramel coloring before consuming the food.[9][10]