Synthetic Food Colorants

Regulation of Food Colors Synthetic Food Colors Natural Food Colors Uses of Food Colors... 

C. Cal2olari, L. Coassini, and L. ToUat, QuademiMerceol 1, 89—131 (1962). Synthetic Food Colors. Reviews the regulation of food colors in various countries, the toxicity of the intermediates used to prepare them, and the toxicity of the degradation products of colorants. 

S. H. Hochheiser, Synthetic Foods Colors in the United States A. History Under Regulation, University Microfilms International, 83-04269, Ann Arbor, Mich., 1986. An excellent history of the development of legislation to control colorants used in foods, dmgs, and cosmetics. 

J. Walford, ed.. Developments in Food Colours, Vols. 1 and 2. Elsevier AppHed Science, London, 1980 and 1984. Includes chapters on synthetic and natral food colors used in the United States, and on the influence of color on the perception and choice of food. 

Carotenoids have two general characteristics of importance to the food iadustry they are not pH sensitive ia the normal 2—7 range found ia foods, and they are not affected by vitamin C, making them especially important for beverages. They are more expensive than synthetic food dyes and have a limited color range. In their natural environment they are quite stable, but they become more labile when heated or when they are ia solution. Under those conditions, there is a tendency for the trans-double bonds to isomerize to the cis-stmcture with a subsequent loss of color iatensity. The results of controlled tolerance and toxicity tests, usiag pure carotenoids, iadicate that they are perfecdy safe as food colors (132). 

The use of natural dyes as food colorants evolved over a period spanning thousands of years. During that period, by trial and error, some dyes were found to be safe while others were not. By comparison, the development of synthetic dyes as food colorants has taken place over a comparatively short time. During that period, some synthetic dyes considered safe by existing health standards were used as food colors. Later, with iacreased knowledge, these were found to create health problems and were removed from the marketplace. The manufacture of synthetic dyes for use on foods creates more of a health and environmental problem than natural dyes, but offers greater variety and stabiUty of color (see Dyes, environmental chemistry). 

Analysis of Synthetic Chlorophyll-Based Food Colorants.442... 

ANALYSIS OF SYNTHETIC CHLOROPHYLL-BASED FOOD COLORANTS... 

Detailed information about carotenoids found in food or extracted from food and evaluated for their potential as food colorants appeared in Sections 4.2 and 6.2. We would like to mention some new data about the utilization of pure carotenoid molecules or extracts as allowed food additives. Looking to the list of E-coded natural colorants (Table 7.2.1), we can identify standardized colorants E160a through f, E 161a, and E161b as natural or semi-synthetic derivatives of carotenoids provided from carrots, annatto, tomatoes, paprika, and marigold. In addition, the extracts (powders or oleoresins) of saffron, - paprika, and marigold are considered more economical variants in the United States and European Union. 

As an example, five different synthetic colorants (Tartrazine, Sunset Yellow, Ponceau 4R, Amaranth, and Brilliant Blue FCF) from drinks and candies were separated on a polyamide adsorbent at pH 4, eluted with an alkaline-ammonia solution. By another method, 13 synthetic food colorants were isolated from various foods using specific adsorption on wool. After elution with 10% ammonia solution and gentle warming, an absorption spectrum of the resulting colorant solution was recorded, compared to the reference spectra of pure colorants, and identified by linear regression analysis. ... 

Maxima of Light Absorptions of Synthetic Food Colorants Determined by UV-Vis Spectrophotometry... 

HPLC is often reported to be the technique of best choice for the quantification of food colorants. According to European Directive 94/36/EC, the quantities of synthetic colorants to be added to foods are restricted and thus reliable methods for their quantification must be established. Approved colorants, defined by E-coded numbers (Table 6.6.2), are permitted for non-alcoholic beverages, confectionery products, and even for caviar (dying fish roe). For example, a specific HPLC chromatographic method for the quantization of 14 synthetic food colorants belonging to azo dye, triphenyhnethane, or quinophthalone classes (E 102,104, 110, 122,123, 124, 127, 128, 129, 131, 132, 133, 142, 151) was reported to check their contents in caviar. ... 

Hofer, K. and Jenewein, D., Quick spectrophotometric identification of synthetic food colorants by linear regression analysis, Z. Lebensm. [Inters. Forsch., A204, 32, 1997. 

Kirschbanm, 1. et al.. Development and evaluation of an HPLC-DAD method for determination of synthetic food colorants, Chromatogr. Suppl., 57, 115, 2003. 

Kuo, K.L., Huang, H.Y., and Hsieh, Y.Z., High-performance capillary electrophoretic analysis of synthetic food colorants, Chromatographia, 47, 249, 1998. 

The present market for food colorants is estimated at 1 bilhon USD, while the natural food colorant market is only one-third of it. Synthetic colorants have achieved better results than natural or nature-identical colorants until now because of greater stabihty and higher ratios of coloring yield. 

In recent decades, the synthetic colorant market has dechned, to the benefit of the natural-oriented market and consumers. Excluding FD C Red 40 and Red 28, the synthetic colorants are now as well accepted as they were. In addition to the decreasing enthusiasm for chemicals in food, the high costs of toxicological studies also inhibit the development and approval of new synthetic colorants. The existing technologies used for the extraction, concentration, and purification of natural plant pigments to be used as food colorants still produce lower yields and the final products are still expensive. 

Colorants were the first food additives subjected to governmental regulation in the United States (US). After successive toxicological evaluations, the Food and Drug Administration established a list of permitted colorants and lakes. Only 7 synthetic pigments (and 2 others with restrictions) and 6 of their lakes are now permitted as food colorants in the US while 17 are permitted in the European Union (EU) see Table 7.3.L - ... 

Despite the new orientation toward utilization of natural compounds, synthetic colorants are still used as food additives. Synthetic colorants are easy to produce, stable, less expensive, and have better coloring properties than natural colorants. Still, synthetic colorants are considered to belong to concern level III, a category... 

Synthetic Food Colorants Used as Certifiable Dyes or Lakes and Current Status... 

Synthetic food colorants are chemically synthesized compounds that have a large variety of structures. The structures (Figure 7.3.1) and main properties of some of these pigments are presented below. Depending on their structural characteristics, synthetic pigments used as food colorants can be classified as follows ... 

Synthetic Food Colorants and Their Uses as Food Additives... 

In the food industry, synthetic dyes can be used also in the form of lakes obtained by precipitation of a soluble colorant onto an insoluble base. There are several insoluble bases, but only alumina is permitted for food application by FDA and EU regulation. All the synthetic food dyes can be obtained and used in food in the form of aluminium lakes, except erythrosine due to concerns about inorganic iodine content. 

Synthetic food colorants offer the primary colors (red, green, bine) and others offer yellow and orange. The food, textile, and cosmetic indnstries continne to need wider ranges of shades and hnes. These can be obtained by the process of colorant blending. 

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