Colored compounds produced during

Phenolic compounds. The anthocyanlns and tannins are particularly Important constituents of wine grapes in that they provide the attractive color to red wines and the desirable bitterness and astrlngency associated with the table wines. While the concentrations and types of anthocyanlns present in the various cultivars and species differ, most red wine grapes contain enough of these compounds in the skins so that satisfactory colors are produced during the fermentation of the wine when the... 

The Maillard reaction is chiefly responsible for the desirable colors and flavors that occur when many foods are heated. A substantial amount of data has been obtained relating to the volatile aroma compounds produced during the reaction (e.g. l-3 and this is due largely to the success of gas chromatography-mass spectrometry as a technique for the separation and identification of volatile compounds. Information relating to the factors affecting the formation of these aroma compounds is also available (c.g. 4-7). 

Melanoides Color-producing compounds produced during Maillard reactions that start with the combination of reducing sugars and amino acids. 

Throughout the course of MOX trials with commercial scale Monas-trell wines, the concentration of acetaldehyde was not found to increase over a 5-month period (Cano-Lopez et ah, 2006), even though more colored compounds involving acetaldehyde were found to form in the MOX wines (see below). However, in similar trials, the acetaldehyde concentration was higher with the MOX treatments after a final MOX phase at 3 mL/L/month post-MLF by up to an additional 13 mg/L both free and total SO2 were depleted in the MOX wines by the end of the trial (Cano-Lopez et ah, 2008). In these trials, the MOX operation was discontinued during MLF for a period of 1-2 months, on the expectation that the bacteria will consume the acetaldehyde produced during this period. 

Compare the colors of the original compounds to the colors of the energy released during this demonstration and explain how colorless compounds produced colored light. 

Color formation during aqueous sucrose degradation appears to be temperature dependent since colored compounds are produced rapidly at 130°C. Color formation is also increased with the presence of impurities such as amino acids (23). 

Lewis et al. (1960) report that cystine is degraded during the acid hydrolysis of wool with the appearance of seven new sulfur-containing compounds, one of which is cysteine. These compounds produce color in the Shinohara reagent, although the color yield differs from that of cystine. Fletcher and Robson (1962a, 1963) have isolated another of these compounds and identified it as bis(/3-amino-/3-carboxyethyl)trisulfide. There was evidence also for the presence of the corresponding tetrasulfide. 

Coal tars are by-products of the carbonization of coal to produce coke and/or natural gas. Physically, they are usually viscous liquids or semi-solids that are black or dark brown with a naphthalene-like odor. The coal tars are complex combinations of polycyclic aromatic hydrocarbons, phenols, heterocyclic oxygen, sulfur, and nitrogen compounds. By comparison, coal tar creosotes are distillation products of coal tar. They have an oily liquid consistency and range in color from yellowish-dark green to brown. The coal tar creosotes consist of aromatic hydrocarbons, anthracene, naphthalene, and phenanthrene derivatives. At least 75% of the coal tar creosote mixture is polycyclic aromatic hydrocarbons (PAHs). Unlike the coal tars and coal tar creosotes, coal tar pitch is a residue produced during the distillation of coal tar. The pitch is a shiny, dark brown to black residue which contains polycyclic aromatic hydrocarbons and their methyl and polymethyl derivatives, as well as heteronuclear compounds... 

Elemental bromine that has been produced during oxidative decomposition of organic compounds by chromic-sulfuric acid, can be detected directly and in minimal amounts through reaction with -aminophenol. A blue water-soluble product results. The basis of the color reaction is that the initial oxidation product is -quinone imine which reacts with unaltered aminophenol to form an indamine. (See detection of j -aminophenol, Vol II page 517). 

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