Natural pigments development

Yaron, A. and Arad (Mails), S., Phycobiliproteins — blue and red natural pigments — for use in food and cosmetics, in Food Flavors, Ingredients and Composition Developments in Food Science, Vol. 32, Charalambous, G., Ed., Elsevier, London, 1993, 835. 

We have observed a decreasing interest in the development of new synthetic colorants, while increased efforts are directed toward the discovery of new natural pigments and the development of extractions and formulations of natural colorants. ... 

The method was proposed for the approximate prediction of the retention of analytes in gradient elution and for the facilitation of the development of optimal gradient elution strategy [86], This prediction and optimization procedure is similar to those discussed above, consequently, its application in the field of RP-HPLC analysis of natural pigment may be similar. 

Organic modifiers have been frequently employed in CE to increase the solubility of hydrophobic solutes in the aqueous buffer system. Unfortunately, many organic modifiers are UV absorbent and cannot be used without considerable loss of sensitivity of detection. A contactless conductivity detection system has been developed which extends the application range of UV-absorbing solvents [ 119]. As both natural pigments and synthetic dyes absorb in the visible part of the spectra, the application of UV-absorbing organic modifiers in their CE analysis does not cause detection problems. 

It was not until the nineteenth century that artists began to purchase ready-made commercial paints. Today paint colors have standardized specifications. Regardless of type, paint still consists of pigment and binder, as it has for centuries. Many colors originally produced from natural pigments are now made synthetically. The metal paint tube was developed in 1841. Paints that for centuries had been mixed and stored by the artist in various ways in the studio were suddenly available in an easily portable container. Artists who had found it difficult to paint on location were able to create many masterpieces outdoors, on location, as a result of tube paint becoming available. 

One major reason for nutrient loss and off-flavor development today is due to extended exposure to fluorescent light in food retail display cases. Many foods and beverages are susceptible to light-induced reactions, especially those with photo-sensitizers. Natural pigments found in foods that commonly act as photochemical initiators are flavonoids, riboflavin (vitamin B2), chlorophyll, heme, and vitamin K. 

Angeli38,112 first observed that pyrrole with hydrogen peroxide in acetic acid developed a dark color and later a black precipitate. This product, which contains oxygen, was named pyrrole black . Its physical characteristics were very similar to those of natural melanins and this fact stimulated research on the structure of this product, considered an interesting model for natural pigments. 

Coupled spectroscopic methods such as TLC-UV (ultraviolet) and visible spectroscopy, TLC-mass spectrometry, and TLC-FTIR (Fourier transform infrared) have been developed to overcome this difficulty [7]. Their future application in the TLC analysis of natural pigments will markedly increase the information content of this simple and interesting separation technique. The automation of the various steps of TLC analysis (sample application, automated developing chambers, TLC scanners, etc.) greatly increased the reliability of the method, making it suitable for official control and legislative purposes [8]. 

As indicated in our earlier article, the direct polymerization of monopyrroles to porphyrins is of little synthetic value as far as Ae unsymmetrical natural pigments are concerned. However, this might provide a feasible approach at l( ast to the copro- and uroporphyrins if sufficiently sophisticated methods could be developed for their chromatographic separation on a preparative basis. This has already been achieved analytically by high performance liquid chromatography (hplc). ... 

A number of anthocyanins are used as food additives (Harbome and Grayer, 1988 Strack and Wray, 1989 Tim-berlake and Henry, 1988). Anthocyanins also are important in that they control the marketability and taste properties of many commercial products. The sale price of many fruits and vegetables is dependent on full color development. Some major commercial sources of these natural pigments are grapes (Vitis vinifera), roselle (Hibiscus sabdarijfa), blueberries (Vaccinium spp.), and red cabbage (Timberlake and Henry, 1988). 

Carotenoids are an important group of natural pigments with pronounced antioxidant activity, provitamin A factor, and many health benefits. The structure with conjugated double bonds governs mainly the proprieties of color, stability, detection, and quantification. With an increase of namral carotenoid markets, more different sources will be necessary and new technologies will be developed greener and cleaner, showing how promissory and profitable industrial sector can be. 

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