Colorants undesirable properties

It is well known that caramels from ammonia processes used to have a higher tinctorial strength than the other caramels. Even so, the color properties of ammonia caramels may appear to be insuflicient. All attempts to produce a caramel of higher tinctorial strength may result in formation of a product having other undesirable properties, among them, a higher content of 4(5)-methylimidazole. Decades ago, studies were developed on the en-... 

In the baking industry a-amylase from fungi is used in order to release dextrin and fermentable sugars for yeast metabolism. Exhaustive dextrin formation, however, will lead to undesirable properties like loaf stickness and dark color. 

To refuse to accept, consider, take for some purpose, or use. In mechanical process technology particles that are too large (OVERSIZE) or too fine (UNDERSIZE, EINES) or exhibit other undesirable properties (for example in regard to shape, color, composition). 

Cationic polymerization of coal-tar fractions has been commercially achieved through the use of strong protic acids, as well as various Lewis acids. Sulfuric acid was the first polymerization catalyst (11). More recent technology has focused on the Friedel-Crafts polymerization of coal fractions to yield resins with higher softening points and better color. Typical Lewis acid catalysts used in these processes are aluminum chloride, boron trifluoride, and various boron trifluoride complexes (12). Cmde feedstocks typically contain 25—75% reactive components and may be refined prior to polymerization (eg, acid or alkali treatment) to remove sulfur and other undesired components. Table 1 illustrates the typical components found in coal-tar fractions and their corresponding properties. 

Freedom from irritation, undesirable odor, color, and staining properties... 

These nonenzymatic reactions are responsible for numerous changes on food properties and may impair food safety. Although these reactions are of great importance in the production of aroma, taste and color, they are often accompanied by a reduction of the nutritive value of different foods and by the formation of toxic compounds harmful for human health (Ledl and Schleicher, 1990). Results of nonenzymatic browning can be either desirable or undesirable. The brown crust formation on bread is desirable the brown discoloration of evaporated and sterilized milk is undesirable. For products in which the browning reaction is favorable, the resulting color and flavor characteristics are generally experienced as pleasant. In other products, color and flavor may become quite unpleasant. 

Four major objectives in the chemical modification of food proteins are (a) the blocking of deteriorative reactions (b) improvement of physical properties (c) improvement of properties related to acceptability, such as flavor and color and (d) improvement of nutritional properties. Modifications also may aid the physical separation from crude animal, plant, or microbial material and may inactivate or remove relatively small amounts of undesirable substances. There is considerable interest among food technologists in chemical modification as a means of changing the physical characteristics of proteins to give, e.g., better solu-... 

The color formulation binder system can also have undesirable effects on strength properties. If the binder in a liquid color concentrate, for example, plasticizes the let-down resin, you can expect the flexural properties and HDT to decrease. Some universal carrier systems have only limited compatibility with many resins and separate out as a separate phase. The unwanted effects include delamination and loss in tensile and impact strength. 

A number of multidimensional analyses have been developed that provide powerful methods for characterizing these polymers. Linking a liquid chromatogram to a pyrolysis gas chromatograph [l 9] can determine the breadth of the composition distribution, as the method fractionates the SAN copolymer before pyrolysis. This information is useful for determining the source of variation in SAN copolymer properties. Composition drift towards high acrylonitrile-containing fractions can lead to undesirable yellow color, and excessively broad composition drift can cause opacity and brittleness in the material due to phase separation... 

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