Natural Yellow

The colorant is used at 2—50 ppm as pure color to shade margarine, shortening, butter, cheese (4 ), baked goods, confections, ice cream, eggnog, macaroni products, soups, juices, and beverages (58). Its chief advantages over other colorants are its nutritional value and its abiUty to dupHcate natural yellow to orange shades. 

Turmeric and Turmeric Oleoresin. Turmeric (Cl Natural Yellow 3, Cl No. 75300, EEC No. E 100) is the dried and ground rhizome or bulbous root of Curcuma longa, a perennial herb of the Zingiberaceae family native to southern Asia and cultivated in China, India, South America, and the East Indies. It is a yellow powder with a characteristic odor and a sharp taste. 

Lapacol [84-79-7] (Cl Natural Yellow 16 Cl 75490) (lapachic acid, taiguie acid, tecomin) is a yellow pigment occurring in the wood of trees of the genus Tecoma native to the West Indies and tropical South America. The shavings of the wood, treated with lime water, give an extract that dyes cotton yellow. 

The yellow dye curcumin, [458-37-7] (Cl Natural Ye//oii> 3 Cl 75300) (41), also known as tumeric, occurs in the roots of the plant Curcuma tinctoria found growing wild in Asia. The dye was well known to the ancient Romans and Greeks who used it to dye wool, cotton, and silk. The dye is an oil-soluble bright yellow material, and is the only natural yellow dye that requires no mordant. It finds use as a colorant for baked goods such as cakes. 

Crocetin [27876-94-4] Cl Natural Yellow 6 Cl 75100) occurs in saffron as crocin [42553-65-1] (46), the digentiobiose ester of crocetin (47). 

Kamikura, M. and Nakazato, K., Natural yellow colours from gardenia fruit and colours found in commercial gardenia extract analysis of natural yellow colours by high performance liquid chromatography, J. Food Hygiene Soc. Japan, 26, 150,1984. 

Noda, N. et ah. Determination of natural yellow dye from the fruits of gardenia by detecting geniposide, J. Hygenic Chem. (Eisei Kagaku), 29, 7, 1983. 

Hofenk de Graff, J. H. and W. G. T. Roelofs (1978), The analysis of flavonoids in natural yellow dyestuffs occurring in ancient textiles, Proc. bit. Council of Museums Committee for Conservation, 5th Trienial Mtg., Zagreb. 

In all the above processes, the optimised quantities of the chemicals indicated will be specific to the substrate quality evaluated. They would require further re-optimisation for each substrate to take account of the type and concentration of size, the presence of other impurities and the degree of natural yellowness. In particular, the amount of oxidant will need to be adjusted to give the optimum balance between oxidative desizing and the degree of bleaching required. 

E.S.B. Ferreira, A. Quye, H. McNab, A.N. Hulme, J. Wouters and J.J. Boon, Development of analytical techniques for the study of natural yellow dyes in historic textiles, Dyes in History and Archaeology, 16/17, 179 186 (2001). 

Natural zircons heated at 800 °C during one hour when natural yellow broadband luminescence nearly totally disappears and irradiated by different doses of alpha particles. 

This is the kind of information that one may obtain, using the detector without sampling of a painting. Figure 15 shows the setup for analyzing a painting in which a tan ribbon is aligned with the center of the detector. The spectrum obtained is shown at the bottom and is that of a typical natural yellow ochre. 

The flavone morin (700) (Natural Yellow C.I. 75660) dyes wool yellow, the actual shade being determined by the mordant which is used. It has also been mentioned as a spot test reagent for salts of aluminum, beryllium, zinc and other metals (B-54MI22401). 

The principal red and yellow pigments are Lead chromate chrome yellow, orange and red), zinc chromate zinc or buttercup yellow), barium chromate lemon yellow or yellow ultramarine) various products based on jerric oxide, hydrated (yellow) or anhydrous (red), both natural yellow and red ochres) and artificial Mars yellow, English red, etc.) red oxide oj lead minium or red lead) mercuric sulphide cinnabar, vermilion) antimony oxysulphide antimony cinnabar) cadmium sulphide cadmium yellow) basic lead antimonate Naples yellow). 

In this connection it must be borne in mind that in some of these extraction tests on naturally coloured and raw cotton, flax, wool, hair, etc, an appreciable quantity of yellowish-brown colouring matter is removed, and that raw silks of a natural yellow or green colour exhibit special behaviour if subjected to some of these tests, eg, to treatment with concentrated acids ... 

Fustic Yellow Maclurin, Morin C.I. Natural Yellow 8, 11, resp. 

Maize gluten meal is not a very suitable feed for poultry since it is of relatively low palatability and being very deficient in lysine has an imbalanced AA profile. However, it can be incorporated in broiler and layer diets as a source of natural yellow pigment since it is rich in xanthophyll pigments (up to 300mg/kg). Maize gluten meal may no longer be available or economic for feed use as it is used extensively as a natural weed-killer in horticulture. 

Figure 4.16 Polarized absorption spectra of natural and synthetic sapphires (from Bums and Bums, 1984a). (a) Natural yellow sapphire (b) natural dark blue sapphire (c) synthetic Ti-doped A1203 (d) synthetic Fe-Ti-doped A1203. —Ellc spectra -----EJx...

Representative optical spectra of various sapphires are illustrated in fig. 4.16. It is apparent from the spectra of the natural blue sapphire (fig. 4.16b) that absorption minima in the violet-indigo and blue-green regions, which are located between sharp peaks at 25,680 cm-1 and 22,220 cm-1 and broad bands spanning 17,800 to 14,200 cm-1, are responsible for the blue coloration. Absorption at 17,800 to 14,200 cm-1 is less intense in spectra of natural yellow sapphire (fig. 4.16a see also fig. 3.21) containing negligible Ti. The spectra of synthetic Ti3+-doped A1203 (fig. 4.16c) show absorption maxima at... 

Ferguson, J. Fielding, P. E. (1972) The origins of the colours of natural yellow, blue and green sapphires. Austral. J. Chem., 25, 1371—85.. 

Natural yellow plant dyes such as curcumin and berberine are much less intense, but sometimes the use of such colorants could lead... 

---