Industrial caramel

Industrial caramel, known from the beginning to be essentially a mixture of burnt sugar polymers (Salamon, 1900), arises from the controlled action of heat on dry sugar or concentrated sugar solutions with or without acid,... 

Liquorice is a slightly unusual example of a starch gel instead of separating the starch, wheat flour is used directly. It is also a product where brown sugars and treacle are used. Liquorice paste is typically made from treacle, wheat flour, liquorice extract and caramel. Caramel in this context means the brown colour produced from sugar and not a form of toffee. Industrial caramel is made by the action of ammonium hydroxide on a carbohydrate, typically glucose syrup. The resulting product is not well defined chemically, and for this reason its use is recommended to be limited to 0.2% maximum. 

Phenolic phenol formaldehydes (PFs) are the low-cost workhorse of the electrical industry (particularly in the past) low creep, excellent dimensional stability, good chemical resistance, good weatherability. Molded black or brown opaque handles for cookware are familiar applications. Also used as a caramel colored impregnating plastics for wood or cloth laminates, and (with reinforcement) for brake linings and many under-the-hood automotive electricals. There are different grades of phenolics that range from very low cost (with low performances) to high cost (with superior performances). The first of the thermosets to be injection-molded (1909). 

In chocolate milk, the muddy color of caramel is darkened by the addition of FD C Red 40 to give what the industry refers to as a Dutch chocolate shade. Blues and yellows are sometimes added to create a browner color. 

The literature in this field is confusing because of a somewhat haphazard method of nomenclature that has arisen historically. This is compounded by some mistakes in structure determination, reported in early papers, and which are occasionally quoted. The first part of this chapter deals with nomenclature and with a brief overview of early work. Subsequent sections deal with the formation and metabolism of di-D-fructose dianhydrides by micro-organisms, and the formation of dihexulose dianhydrides by protonic and thermal activation. In relation to the latter topic, recent conclusions regarding the nature of sucrose caramels are covered. Other sections deal with the effects of di-D-fructose dianhydrides upon the industrial production of sucrose and fructose, and the possible ways in which these compounds might be exploited. An overview of the topic of conformational energies and implications for product distributions is also presented. 

The oldest way to produce caramel is by heating sucrose in an open pan, a process named caramelization. Food applications require improvement in caramel properties such as tinctorial power, stability, and compatibility with food. Caramels are produced in industry by controlled heating of a rich carbohydrate source in the presence of certain reactants. Carbohydrate sources must be rich in glucose because caramelization occurs only through the monosaccharide. Several carbohydrate sources can be used glucose, sucrose, com, wheat, and tapioca hydrolysates. The carbohydrate is added to a reaction vessel at 50°C and then heated to temperatures higher than 100°C. Different reactants such as acids, alkalis, salts, ammonium salts, and sulfites can be added, depending on the type of caramel to be obtained (Table 5.2.2). 

Mother liquor at 90% dextrose from the first crop of crystals can be concentrated and crystallized in a similar manner to recover an additional crystal crop. Depending on quality, some mother liquor can be partially recycled to the initial crystallization step to increase crystal-phase yield as a single crystal crop. The overall yield depends on the dextrose content of the original hydrolyzate and the extent to which hydrolyzates are refined. The mother liquor from the second crystallization contains less than 80% dextrose. The material is evaporated to 71% solids and sold as hydrol to the tanning and fermentation (qv) industries and for the manufacture of caramel color. 

Chemical modification of simple sugars during drying, baking, or roasting operations can either have a desirable or undesirable effect upon the organoleptic quality of the final product. We have become accustomed to the characteristic roasted or baked flavors of coffee, peanuts, popcorn, and freshly-baked bread. The color and flavor and aroma of caramel make it a useful additive for the food industry. On the other hand, the burnt flavor of overheated dry beans or soy milk reduces marketability of these products. 

Pyrazines. In the thirties, the attention on pyrazines was focused on its industrial role in dyes, photographic emulsions and chemotherapy. Its importance in life processes was indicated in its derivative, vitamin B2 (riboflavin, 6,7-dimethyl-9-(l -D-ribityl isoalloxazine). Later,in the midsixties, it was identified in foods and its contributions to the unique flavor and aroma of raw and processed foods attracted the attention of flavor chemists Pyrazine derivatives contribute to the roasting, toasting, nutty, chocolaty, coffee, earthy, caramel, maple-like, bread-like, and bell pepper notes in foods. The reader is referred to the reviews on Krems and Spoerri (88) on the chemistry of pyrazines, and the review of pyrazines in foods by Maga and Sizer (89, 90) Table XVI summaries sensory description and threshold of selected pyrazines. 

Caramel is unintentionally generated in burnt carbohydrate foods (rice, oatmeal, cornmeal, etc.) and molasses (Kowkabany et al., 1953) it is the source of maple flavor and color in the concentration of maple sap to maple syrup (Stinson and Willits, 1965). In industrial manufacturing, the intended application is taken into account, because reaction conditions help determine the properties of the pyrolysate, e.g., its tinctorial value, water solubility, and alcohol stability. Tinctorial value refers to the absorbance at 560 nm of a 0.1-wt/vol% solution in a 1-cm cell. Tinctorial strength increases with acidity, temperature, and duration of heating. Caramel manufactured above pH 6.3 is biologically unstable and much below pH 3.1, it is a resin. 

The confectionery industry utilizes the emulsification, antistick, and viscosity properties of lecithin and benefits from the concurrent effects of shelf-life extension, texture improvement, and decreased production costs (83). A product such as caramel will not blend correctly in the absence of lecithin. Uniform dispersion of fat, aided by lecithin, will decrease stickiness and provide tenderness for ease of cutting. The natural antioxidant properties of lecithin slow the decay of any product in which it is incorporated. Viscosity is very important in the chocolate industry where shape is often a requirement for consumer acceptability. High concentrations of butter, such as cocoa butter, impart high viscosity, which in turn makes... 

Emulsifiers have also assumed valuable roles in products such as chocolates (control of fat polymorphism), toffees and caramels, chewing gums, pharmaceutical preparations, soft and liqueur drinks and meat products, in addition to being used as lubricating, release and cutting aids throughout the food industry. In these applications, emulsifiers can be said to be used in roles not directly related to emulsification. 

Cornel in low concentration gives a stable and intense yellow color. Therefore, it was proposed as a color compatible with Yellow No. 5 (tartra-zine) for nontransparent drinks, The wide range of shades of color of caramel has attract the attention of other industries. Thus, coatings and other articles having a cork-like appearance are manufactured from thermoplastic resins colored with caiamel. Coloring of polyethylene terephtha-late with caramel was also patented. Caramel may be formed in situ from carbohydrates in the presence of antimonous oxide as the catalyst the dark-brown polymer resulting is said to be nontoxic. ... 

These chemical reactions and tests for caramel are complemented by a group of physical methods based on size-exclusion chromatography. These methods may be applied for the detection of caramel in beverages, beer, and wine. Caramel may be detected in bread and in various slightly colored products from the sugar industry (raw sugar, molasses, sugar syrups, and the like). Spectral methods are most useful for these purposes. 

Most recent evidence indicates that DFAs can even protect the intestinal tract against agressive agents favor the assimilation of antioxidants, and act as a druglike food for the treatment of colon ailments such as inflammatory bowel disease (Crohn disease). The development of efficient methodologies for the preparation of DFA-enriched caramels, compatible with the food and agricultural industry regulations, may lead to new natural functional foods and nutraceuticals based on DFAs in the near future. 

As in the case of molasses, the color of different samples of caramel varies in intensity. Usually 4 to 6 grams of caramel per liter of water will give a satisfactory solution. The method of buffering the solution and the procedure for conducting the test parallel those used for molasses. During the early development of carbons for the treatment of liquids, this test was extensively used. Since then, it has been found that the test has very little relation to the removal of impurities from most industrial solutions and is seldom used now. 

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