Coloring agents, additives

Flour Bleaching Agents and Bread Improvers. Freshly milled flour contains carotenoid pigments that cause the flour to have a yellow color. In addition, when the flour is made into dough the product is sticky and unmanageable. As the flour ages, a natural process takes place which turns the flour white and improves its baking qualities. Because the natural process takes quite a bit of time, additives are used to speed up the process. 

Plastics and Resins. Plastics and resin materials are high molecular weight polymers which at some stage in their manufacture can be shaped or otherwise processed by appHcation of heat and pressure. Some 40—50 basic types of plastics and resins are available commercially, but HteraHy thousands of different mixtures (compounds) are made by the addition of plasticizers, fillers, extenders, stabilizers, coloring agents, etc. 

The information presented in this chapter is intended to provide a brief overview of the composition, performance, and formulation properties of LAS by itself and in combination with other surfactants. The particular performance synergies and processing characteristics of certain combinations of surfactants are discussed briefly. The examples of mixed active formulations provided herein represent to the best of the author s knowledge the approximate levels of major surfactants in actual household detergent products both past and present. This does not imply that these formulations are complete because many additives, such as bleaches, enzymes, builders, hydrotropes, thickeners, perfumes, and coloring agents, may also be present in varying amounts. 

Copper compounds are used in agriculture to treat mildew and other plant diseases in the food industry as preservatives, additives, or coloring agents in preservatives of wood, leather, and fabrics in coin manufacture and in water treatment (ATSDR1990 Roncero et al. 1992). The use of copper-containing pesticides is traditional along the Mediterranean Coast, especially the use of Bordeaux mixture, a copper sulfate-based fungicide that has been widely used for more than a century to... 

As a soil develops, OM decomposes to produce humus, which is black. Additionally, release of iron from minerals by weathering yields various reds and yellows. Both mechanisms yield soil coloring agents. Under oxidizing conditions, where soil is not saturated with water, the iron will be oxidized and thus in the ferric state [Fe(III)]. When the iron and OM are deposited on the surfaces of sand, silt, clay, and peds, they develop a coat that gives them a surface color. However, soil color is not only a surface characteristic but extends through the soil matrix. Under oxidizing conditions, soil has a reddish color. The chroma of this color depends to some extent on the amount of and the particular iron oxide present. 

Additional colorant agents were previously prepared by the authors (1) and are described. 

Parabens are approved for use in oral solution and suspensions at a concentration of 0.015% to 0.2% w/v. Due to their low solubility, the sodium salts of parabens are often used in aqueous formulations. The parabens are most effective in the pH range of 2 to 6, and their antimicrobial activity decreases with increasing pH. Additionally, they are very unstable at pH 8 or above in solution. Methyl paraben has also demonstrated incompatibility with sorbitol and may show some discoloration in the presence of iron. The absorption of methylparaben by plastics has been reported with the amount absorbed being dependent upon the type of plastic and vehicle. However, no absorption has been reported for low density polyethylene (LDPE) or high density polyethylene (HDPE) containers. Certain coloring agents such as yellow iron oxide, ultramarine blue, and aluminum silicate can extensively absorb ethyl paraben in simple aqueous systems, thus reducing its preservative efficacy. 

Additionally, a list of the coloring agents that have had their certification cancelled can be found at the following website http //www.cfsan.fda.gov/ lrd/cfr81-30.html. 

Additionally, the stability of dyes in solution can be dependent upon the specific excipients used in the formulation. For example, FD C Blue 2 was found to fade more rapidly in the presence of several sugars (sorbitol, mannitol, dextrose, sucrose, and lactose) and that the nonionic surfactant Pluronic F-68 promoted the fading of FD C Blue 2. The combination of coloring agents can lead to complications... 

RL Newsome. Natural and synthetic coloring agents. In AL Branen, PM Davidson, S Salminen, eds. Food Additives. New York Marcel Dekker, 1989, pp 297-326. 

Since the compound hydroxymethyl furfural is a major product of ketohexose dehydration, its presence can be used as an indication that caramel has been added as a coloring agent in a nonheated food system (66). In contrast, ketopentose dehydration produces furfural. Another dehydration product, bis-5,5 -formylfurfurly ether, can also be used to confirm the addition of caramel color (66). 

These new man-made chemicals are everywhere. Some 2-3000 are used as food additives 30 are used as preservatives 28 as antioxidants 44 as sequesterants 85 as surfactants 31 as stabilizers 24 as bleaches 60 as buffers, acids or alkalies 35 as coloring agents 9 as special sweeteners ... 

Compounding—Processing operation in which fillers, plasticizers, coloring agents, and other additives are mixed with a polymer, often in an extrude to obtain desired properties. 

Potentiality for the addition of suitable coloring agents not easily faded by light. 

Source Reprinted with permission from R.L. Newsome, Natural and Synthetic Coloring Agents, in Food Additives, A.L. Branen, P.M. Davidson, and S. Salminen, eds., p. 344, 1990, by courtesy of Marcel Dekker, Inc. 

---