Caramelization, carbohydrates

Defaye, K. and Garcia Fernandez, J.M., Protonic and thermal activation of sucrose an the oligosaccaride composition of caramel. Carbohydrate Res., 256, Cl, 1994. Ratsimba, V. et al.. Qualitative and qnantitative evaluation of mono- and disaccharides in D-fructose, D-glucose and sucrose caramels by gas-liquid chromatography-mass spectrometry di-D-fructose dianhydrides as tracers of caramel authenticity, J. Chro-matogr. A, 844, 283, 1999. 

J. Defaye and J. M. Garcia-Fernandez, Protonic and thermal activation of sucrose and the oligosaccharide composition of caramel, Carbohydr. Res., 256 (1994) C1-C4. 

Caramel. Officially, the color additive caramel is the dark brown Hquid or soHd material resulting from the carefully controlled heat treatment of the following food-grade carbohydrates dextrose, invert sugar, lactose, malt symp, molasses, starch hydrolysates and fractions thereof, or sucrose. Practically speaking, caramel is burned sugar. 

Caramels, chemical nature, 222-223 Carbohydrates definition, 49-50 medical uses, 10... 

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). 

Caramel colors E150a-d Yes Food-grade carbohydrates brown 5L... 

To assess the use of HPLC and fluorophore assisted carbohydrate gel electrophoresis as a means of profiling caramel colour types III and IV. 

Commercial caramel is a very complex mixture of heat degraded carbohydrates. In 1980, the JECFA recommended that further information on the chemical properties be obtained in order to establish a suitable classification and specification system. The International Technical Caramel Committee attempted to provide this information and undertook an extensive research program. 

Reaction flavours Thermal treatment of amino acids and reducing carbohydrates based on Maillard reaction Caramel and malt flavours... 

Browning of breads, as induced by baking, is a complex process consisting mainly of the Maillard reaction between flour starch or other carbohydrates and flour protein or other protein-rich additives, and the caramelization of sugar and other carbohydrates. 

As a consequence of bottle aging, carbohydrate conversions can occur, although slowly at cellar temperature, to form the caramel-like 2-furfural aroma for example, in aged Madeira wines. Rapp and Giintert (86MI141) have shown that such carbohydrate decomposition in Riesling wines leads to 2-furfural 9,2-acetylfuran 10, ethyl furan-2-carboxylate 11, 2-formyl pyrrole 12, and 5-hydroxymethylfurfural 13. 

Perhaps one of the most fascinating and complex chemical reactions involving carbohydrates is caramelization. For example, granulated sugar heated at a high temperature in the dry state eventually produces a dark, viscous mass which has a strong and characteristic flavor totally different from the sweet taste of sucrose. 

If a nitrogen source is added, or if residual nitrogen-containing compounds are present, classical non-enzymatic browning (MaiHard) along with caramel ization can occur. Although the Maillard reaction is not the major emphasis of this review, it is difficult not to include it in discussions of carbohydrates and their degradation products. 

Furans are the most abundant products of the Maillard reaction and they account for the caramel-like odor of heated carbohydrates (8). Some sugar degradation compounds, such as maltol, isomaltol, 4-hydroxy-5-methyl-3(2H)-furanone, 2,5-dimethyl-4-hydroxy-3(2H)-furanone, and 2-hydroxy-3-methyl-2-cyclopentene-l-one (cyclotene), have odors usually described predominantly... 

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. 

Class I (Plain Caramel, Caustic Caramel) Prepared by heating carbohydrates with or without acids or alkalis no ammonium or sulfite compounds are used. 

Caramel color can be produced from a variety of carbohydrate sources, but usually com sugar syrup is used. Com starch is first hydrolyzed with acid to a DE of 8 to 9, followed by hydrolysis with bacterial a-amylase to a DE of 12 to 14, then with fungal amyloglucosi-dase up to a DE of 90 to 95. Several types of caramel are produced. The largest amount is... 

Another group of compounds that have been related to the aroma of heated foods is the furanones. Teranishi (1971) summarized the findings on several of the furanones (see Figure 7-23). The 4-hydroxy-2,5-dimethyl-3-dihydrofuranone (1) has a caramel or burnt pineapple odor. The 4-hydroxy-5-methyl-3-dihydrofuranone (2) has a roasted chicory root odor. Both compounds may contribute to beef broth flavor. The 2,5-dimethyl-3-dihydrofuranone (3) has the odor of freshly baked bread. Isomaltol (4) and maltol (5) are products of the caramelization and pyrolysis of carbohydrates. 

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