Colorants sources

Quantitative and qualitative anthocyanin composition must be known in order to determine the feasibility of application of new plant materials as anthocyanin-based colorant sources and to understand the relationships of structures and functions of anthocyanins. In addition, anthocyanin compositions of fruits and vegetables have also been used to detect adulteration of anthocyanin-based products - and as indicators of product quality. - ... 

Use of the natural color and food color terms is not permitted because they may indicate that a color occurs naturally. The acceptable descriptions include artificial color, artificial color added, and color added but they do not provide any real benefit. A preferred description is to note that a product is colored with, then name the color source, e.g., annatto. If the name of the specific color is not included, the label declaration must also state artificially colored or artificial color addedf ... 

Barium nitrate - Ba(N03)2 - and barium chlorate - Ba(C o3)2 are used most often to produce green flames, serving both as the oxidizer and color source. Barium chlorate can produce a deep green, but it is somewhat unstable and can form explosive mixtures with good fuels. Barium nitrate produces an acceptable green color, and it is considerably safer to work with due to its... 

Red cabbage as a colorant source has been studied for many years. As of 1990 at least one firm has introduced San Red RC, the first commercially available food color derived from red cabbage. The color can be used alone or in combination with other colors to create strawberry, cherry, raspberry, and blueberry tones. By way of proprietary technology, the new dye is claimed to be free of flavor and odor defects, which in the past have been associated with red cabbage. The dye is pH dependent. The color tones move toward blue-red as the pH value increases. San Red RC ranks between cochineal and grape juice in percent or color retention. 

Wang et al., 1997) and anticancer properties (Karaivanova et al., 1990 Kamei et al., 1995). Anthocyanins have also found considerable potential in the food industry as safe and effective food colorants (Strack and Wray, 1994) interest in this application has increased in recent years. In 1980, the annual world production had been estimated as reaching 10,000 tons from grapes alone (Timberlake, 1980). Quantitative and qualitative anthocyanin composition are important factors in determining the feasibility of the use of new plant materials as anthocyanin-based colorant sources. 

At the beginning of diffusion, time t = 0 and the total amount of color having mass m is located at position x = 0. Because of the theoretically infinitely thin layer 5x of the color source, the initial concentration there is infinite and the concentrations at all other positions of the bar are zero. The solution of the diffusion equation (7-12) is immediately given as ... 

Third Law Every color except pure spectral colors can be made from any of a large number of combinations of color sources, and those composite colors produced will appear indistinguishable to an observer. 

The description of color on the basis of chromaticity coordinates not only permits an analysis of color but also provides a synthesis technique. Using a mixture of two color sources, it is possible to... 

Tonsils shown to have increased content of cholesterol esters remainder judged abnormal by history and presence of persistent tags or follicles having distinctive orange or yellow-white color. Source Fredrickson (1966). 

Of all the food additives, perhaps the addition of colors is the hardest to justify. Many people feel that foods have a natural color, so why tamper with it. Indeed, color additives have met strong opposition and regulations have been passed banning some and restricting the use of others. Most of the opposition and regulation involves the synthetic colors, while the natural colors receive less attention. However, 90% of the colors used in food come from a small group of synthetic colors, while the diverse group of natural color sources is used in about 1 0% of foods only. 

Fig. 7.10 Influence of dewatering on the rheology of coating colors (source BASF).

Fig. 7.18 Open Screen for filtration of pigment slurry/coating color (source Omya).

Fig. 7.21 Batch preparation of coating colors (source Metso).

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