Color of food or beverage is one of the first attributes recognized by the senses of the purchaser and consumer of the product. The familiar and pleasant appearance of a host of those products is provided by caramel color.
Caramel colors are amorphous, brown to brownish materials resulting from the carefully controlled heat treatment of food grade carbohydrates in the presence of small amounts of food grade acids, alkalis or salts. This definition is in essential agreement with definitions contained in the U.S. Standard of Identity for Caramel. Code of Federal Regulations, Title 21, Sec. 7385; the monograph on caramel as in Food Chemicals Codex, Fourth Edition, the EEC Regulations on Coloring Matter, and the U.K. Specification for Caramel use in Foodstuffs.
Caramelization has been carried out as long as food has been cooked. Caramel color, sometimes referred to as burnt sugar, first gained commercial importance as an additive in brewery products like dark beers, ales and as a colorant for brandy. The chemistry of caramelization is complex and difficult to reduce to simple terms. Larger carbohydrate molecules are reduced in size under the influence of acid, heat and pressure. Then a type of condensation or polymerization takes place in which the simple sugars are recombined into larger complex color bodies. These are similar to those found in common foodstuffs such as roasted coffee, broiled meats and baked goods.
Modern caramel color production in heat controlled closed vessels bears little resemblance to the early preparation by heating sugar in a pan. The introduction early in this century of acid stable caramel color types for the soft drink industry was a significant achievement.
The ingredients or raw materials which may be used in the preparation of caramel color in the United States are listed in the Standard of Identity for Caramel (CFR 21, 73.85). The edible carbohydrates are glucose, invert sugar, malt syrup, molasses, sucrose and starch hydrolysates and fractions of them. Corn starch hydrolysate, that is, corn syrup of high dextrose equivalent is employed most frequently by the caramel color industry.
Certain acids, alkalis and salts as provided by the Standard of Identity may be used as catalysts in amounts consistent with good manufacturing practice to assist caramelization. These acids, alkalis and salts meet Food Chemical Codex specifications.
Caramel color is generally made batchwise in stainless steel reactors equipped with an agitator, heating and cooling coils or jackets of size to contain up to several thousand gallons of liquid sugar. Some types of caramel color are best made in open or atmospheric kettles while other types require closed pressure reactors, capable of up to 70 psi gauge pressure with temperatures up to 320° F.
Product lines, pumps, filters, storage tanks and all contact surfaces are preferably made of 316 stainless steel due to the acidic nature of caramel.
In a typical batch, the required amount of sugar is introduced into the reactor, and warmed to facilitate mixing with liquid catalyst. The vessel is then closed and the reaction proceeds for several hours under controlled temperature and pressure conditions. The composition of the catalyst, the ratio of sugar to catalyst and the pH-time-temperature relationships will vary according to the type of caramel color being produced. When the desired color intensity is reached, the batch is cooled, filtered and pumped into storage.
In-process controls are the key to the production of uniform caramel color batch after batch. Laboratory tests control the composition of the material prior to caramelization. Time-temperature-pressure records are kept during the process. Test samples are withdrawn at intervals during the reaction cycle for the determination of color development, and to monitor changes in specific gravity, pH and viscosity. The reaction end point is determined from a combination of these various factors.
Before a caramel color is offered for sale, a complete evaluation must be made of the finished product. Primarily a caramel color user looks for coloring strength and compatibility with other ingredients. The following tests are made by the caramel color manufacturer to measure these and other critical characteristics:
Caramel color is a complex mixture of compounds, some of which are in the form of colloidal aggregates. Caramel usually is a dark brown to black liquid or solid having an odor of burnt sugar and a somewhat bitter taste. Caramel colors have isoelectric points and pHs varying over a wide range.
In coloring a product with caramel, the particles of the caramel color must have the same charge as the colloidal particles of the product to be colored. If a caramel color is put into a colloidal solution with opposite-charged particles, the particles will attract one another, form larger, insoluble particles and settle out. For example, a soft drink contains negatively charged colloidal particles, and therefore, a negative caramel color should always be used.
Thousands of companies use caramel colors in the manufacture of various foods and beverages. Through the years, a great deal has been learned about the use of this ingredient. The following are items to be considered in developing formulations with caramel color.
third type of caramel color is commonly used in such soft drinks as root
beer. It contributes to the formation of a foamy head and an attractive
Consideration must be given to the charge of the caramel color selected. Beer contains positively charged proteins. Therefore, the addition of negatively charged caramel creates a cloud that agglomerates into particles large enough to precipitate quickly. For this reason, positively charged beer stable caramels should be selected.
Negatively charged caramels (and, sometimes, specifically formulated spirit caramel colors) work well in whiskeys, wines, rums and liqueurs.
Wines clarified using gelatin and tannic acid require enough tannic acid to remove all the gelatin. Otherwise, the remaining positively charged gelatin and negatively charged caramel will precipitate and be removed in the filtration process, making the wine perceptibly lighter.
High (151) proof rums are best colored with a sucrose-based spirit caramel. These products tend to have a higher alcohol tolerance than glucose-based spirit caramels.
For improved stability in liqueurs (especially creme liqueurs), it is important to premix the caramel with alcohol before adding the other ingredients. When using dairy ingredients, it is necessary to control the pasteurizer temperatures to prevent scorching the creme. These scorched creme particles tend to rise, giving the impression of caramel color failure.
Color fading may occur when caramel colored alcoholic beverages are bottled in clear glass. Such products will evidence moderate fade under fluorescent lights; but in direct sunlight the rate of fade increases tenfold. Dark glass bottles are preferred for alcoholic beverages.
Food products: Other products call for other caramel color characteristics. As an example, soy sauce, which can be preserved with up to 15 percent salt, demands a caramel color with the proper salt stability. Usually, positively charged caramel colors have inherent salt stability; special formulas provide stability in negative soft drink caramel colors. Positive types of caramel color give finished soy sauce a hue more closely resembling that of the naturally fermented products. Still other products necessitate the addition of other agents to obtain the proper color. In chocolate milk, caramel colors can create an almost muddy appearance.
Sausage casings are commonly dipped in solutions of caramel color and other colors to give them the desired tone. Here, one problem to guard against is that of bacteriological contamination of a solution held too long or inadequately protected. Caramel colors themselves are essentially sterile: with their high solids content and acidic properties, they're not subject to bacterial attack until diluted.
and gravies containing meat products and colored
with caramel often give a consistent but slightly different shade before
and after retorting. Both positive and negative caramel colors work well
in this application, depending on the shade desired. Positive caramel
colors generally contribute more red hue.
Spice blends normally incorporate caramel color powders with few problems.
Caramel color is used to enhance the attractiveness of baked goods by supplementing the inadequate and irregular coloring power of refined ingredients in rye, pumpernickel, specialty breads, fillings, toppings, cakes and cookies. Several types are used. These include single and double-strength liquid and powdered caramel colors. Caramel color in a powdered (less than 5 percent moisture), free-flowing state is prepared by removing water by drum or spray dryers. This dry product is particularly useful in food systems such as prepared mixes where free moisture is unwanted.
In addition to those applications here detailed, caramel colors are used in a wide variety of products including canned meats and stews, table syrups, pharmaceutical preparations and meat analogs based on vegetable proteins.
Other considerations: Caramel color is a product whose color and viscosity increase with age. Those who use small amounts should be careful not to order too large a quantity, because, depending upon storage temperatures, the caramel color in a 2-year-old drum could be significantly darker than that in a fresh drum of the same product.
Caramel color is generally recognized as safe (GRAS) as a miscellaneous and/or general purpose food additive under CFR section 182.1235, and is deemed to be GRAS by the Flavor and Extract Manufacturers Association, FEMA Number 2235. Caramel color is permanently listed and exempt from certification for use in coloring ingested and topically applied drugs and for use in coloring cosmetics, including cosmetics applied to the area of the eye.
Purity specifications are to be found in the third edition of the Food Chemicals Codex, The National Formulary XV, and the World Health Organization's Composium of Food Additive Specifications-Volume 1, 1992.