Natural colorants range

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). 

Updated infonnation regarding the extraction, purification, and functionalization of natural colors, with special focus on bioencapsulation procedures. The factors that specifically influence the stabihties of a whole range of natural colors, hydrophilic and lipophihc, for example, stabihty in the presence of low pH, fight, and heat, are considered along with solutions in given applications. 

Five synthetic and five natural colorants were identified and quantified in lyo-philized dairy products and fatty foods using an automatic method based on solid phase extraction using a stationary phase followed by RP-HPLC C,g columns for the sequential retention of colorants and diode array detection. Lyophilization of the samples coupled with the separation procedure provided clean extracts despite the complexity of the food matrices and preserved the sample for at least 2 months without changes in colorant concentrations. The detection limits achieved for the colorants were found in a wide range from 0.03 to 75 pg/g of the lyophilized sample, according to the limits established by the European Union. ... 

Pepper breeders are interested in making carotenoid-rich peppers not only for higher vitamin A content but also for use in red pigment extraction. The red pigments are extracted as an oleoresin and used as a natural colorant. This dye is used in a variety of products ranging from cosmetics to food coloring [24]. 

The continually increasing importance of iron oxide pigments is based on their nontoxicity chemical stability wide variety of colors ranging from yellow, orange, red, brown, to black and low price. Natural and synthetic iron oxide pigments consist of well-defined compounds with known crystal structures [3.1] ... 

Copolymers show chemical resistance generally similar to that of polystyrene and terpolvmers similar to that of ABS (acrylonitrile-butadiene-styrene). Neither type is recommended for use in strongly alkaline environments. All impact versions have good natural color and products are available in a wide range of colors. Copolymer crystal grades have good clarity and gloss. 

The reaction products of interest to us in this respect are the salts of hydrogen cyanide, called cyanides,314 in particular, the iron cyanide group, formed by a compound of iron and cyanide. Iron occurs universally in nature. It is iron which gives brick its red color, sand its ochre color, and clay its color ranging from yellowish to reddish-brown. More precisely, we are speaking of iron oxide, popularly known as rust . Basically, all walls consist of at least 1% rust, as a result of sand, gravel, clay, and cement, of which the wall is constructed. 

Most vinyls are naturally clear, with an unlimited color range for most forms of the materials. They generally have in common excellent strength, abrasion resistance, and self-extinguishable. In their elastomeric form vinyls usually exhibit properties superior to those of natural rubber in their flexural life, resistance to acids, alcohols, sunlight, wear, and aging. 

The iron oxides in natural surface environments are often poorly crystalline. i. e. the crystals are nano-sized (>100 nm), do not clearly exhibit the typical morphology of well-crystalline forms, are rich in defects and contain impurities. All this is most probably the result of their formation at low-temperature and in contaminated environments. Due to their striking colors (ranging from red to yellow) and their high surface area, small... 

For colours ranging from yellow to orange, beverage manufacturers have a choice of various natural colorants, depending on the product to be coloured. 

The synthetic organic dyes are superior to the natural colorants in consistency of strength, range and brilliance of shade, stability, ease of application, and cost-effectiveness. However, the manner in which synthetic colorants are employed, from a safety viewpoint, has much to be desired. Therefore, regulations were introduced to control the use of these added food colorants. 

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