Colours natural

Synthetic colours are available for almost all possible shades. Intermediate shades can be produced by blending colours. In general, synthetic colours are much more stable than natural colours to light, heat and extremes of pH. 

Orange or yellow Sunset Yellow FCF E110 Yellow 6 Monoazo 

Orange or Quinoline Yellow E104 Not permitted Quinoline 

Green Green S (Brilliant Green BS) E142 Not permitted Triarylmethane 

Blue Indigo Carmine E132 Blue 2 Indigoid 

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Natural colour Very pale Light Light Light Pale film White thin film White... 

Klaui, H., Carotenoids and Their Applications in Natural Colours for Food and Other, Applied Science, London, 1981, 91. 

Nielsen, S.R. and Holst, S., Developments in natural colourings, in Color in Food Improving Quality, MacDougall, D., Ed., Woodhead Publishing, Cambridge, U.K., 2002. 

Counsell, J.N., Jeffries, G.S., and Knewstubb, C.J., Some other natural colours and their applications, in Natural Colours for Food and Other Uses, Counsell, J.N., Ed., Applied Science, London, 1981, 123. 

Lloyd, A.G., Extraction and chemistry of cochineal. Food Chem., 5, 91,1980. Yamada, S. et al.. Analysis of natural colouring matters in food (IV). Methylation of cochineal colour with diazomethane for analysis of food products, J. Agric. Food Chem., 41, 1071, 1993. 

Some minerals, on being irradiated or acted upon by other external factors, can radiate light the ability to do so is called luminescence. In the case of minerals the natural colour... 

Cochineal (El20). Cochineal is a traditional natural colour. It is made from a Mexican beetle. The only problems with cochineal, apart from expense, is that it is not kosher and it is not animal free. Cochineal is not kosher not because it is made from an insect but because the insect is not itself kosher. 

Within the restrictions outlined curcumin is a successful natural colour. 

Chemically carotenoids have conjugated double bonds that render them liable to oxidation. This tendency to oxidation can be diminished by adding antioxidants to the product. In the sort of product where natural colours are used suitable antioxidants would be tocopherols or ascorbic acid. Chemical antioxidants such butylated hydroxytoluene might be suitable technically but would not fit the image of an allnatural product. Ascorbic acid could be declared as vitamin C rather than as an antioxidant. Oxidation can be started by exposure to light and so this is best avoided. Carotenoids are generally stable to heat. The levels required can be as low as 10 ppm. P-Carotene is available as a nature identical form. 

The actual levels at which additives are used in foods may differ from those listed in the EU Directives since these are intended to achieve the maximum technological effect. In practice use levels might be much lower. For example, it is not always necessary to create very intense colours and the amount of colourant needed will also depend on the natural colour of the matrix. Similarly, many sweeteners are used in combinations in order to control costs whilst avoiding unpleasant side-flavours. This means that in order to gain an accurate impression... 

Natural colours include annatto, anthocyanins, beetroot red (betalaines), caramel, carotenoids, cochineal and lac pigments, flavanoids, chlorophylls and tumeric. There is a trend towards encapsulating natural colours for food use, but this is not yet reflected in the extraction techniques described in the published analytical methods. Lancaster and Lawrence (1996) described the extraction and... 

Numerous CE separations have been published for synthetic colours, sweeteners and preservatives (Frazier et al., 2000a Sadecka and Polonsky, 2000 Frazier et al., 2000b). A rapid CZE separation with diode array detection for six common synthetic food dyes in beverages, jellies and symps was described by Perez-Urquiza and Beltran (2000). Kuo et al. (1998) separated eight colours within 10 minutes using a pH 9.5 borax-NaOH buffer containing 5 mM /3-cyclodextrin. This latter method was suitable for separation of synthetic food colours in ice-cream bars and fmit soda drinks with very limited sample preparation. However the procedure was not validated for quantitative analysis. A review of natural colours and pigments analysis was made by Watanabe and Terabe (2000). Da Costa et al. (2000) reviewed the analysis of anthocyanin colours by CE and HPLC but concluded that the latter technique is more robust and applicable to complex sample types. Caramel type IV in soft drinks was identified and quantified by CE (Royle et al., 1998). 

Lycopene, a carotenoid occurring mainly in tomatoes, is extensively applied as a natural colouring agent in food and food products. 

It was established that each pigment was acylated by hydroxycinnamic acid and the acylation increased the stability of the pigments. Furthermore, the data demonstrated that the tubers of pinta boca can be employed as a natural colourant in the food industry [259],... 

It is indicated for treatment of scurvy, for prophylaxis of vitamin C deficiency, to acidify urine, anaemia of vitamin C deficiency, as antioxidant to protect natural colour and flavour of many foods, dental caries and increased capillary fragility. 

In the present paper a new optical nondestractive method for visualisation of native cells in their natural colours without need for staining is described. A specially designed substrate for deposition of biological samples and observation of their native structure in reflected light has been used [9]. 

Elderberry (Sambucus nigra) is cultivated on small scale in Europe. The fruits have a high concentration of red and purple anthocyanins and a relatively low concentration of sugars, organic acids and aroma compounds, which make this juice attractive as a natural colour ingredient in other red fruit products [126-129]. The fresh green odour of elderberry juice is associated with volatile compounds with typical green notes such as 1-hexanol, 1-octanol, (Z)-3-hexen-l-ol, ( )-2-hexen-l-ol, hexanal and ( )-2-hexenal, whereas the floral aroma is mainly due to the presence of hotrienol and nonanal [127-130]. 

Indigo trisulfate + (+) FIA 5 pg L- Cl2, CIO, Br2, Br not expensive , relatively selective , fast reaction , stability of the sample after adding reagents < 4-6 ht, secondary products do not interfere , need calibration , natural colour of water doesn t disturb Bader and Hoigne, 1981 ) DIN 38406-G3-3 ) Hoigne and Bader, 1980 ) IOA 006/89 (F) Standard methods, 1989... 

When a soft drink is based in pail on fin it juices it may be necessary to restore the appearance of the juice concerned if its natural colours have been destroyed by heat processing, or to intensify these colours when the contribution from the juice is weaker than that normally associated with the effect the compounded drink is intended to convey. Colour adjustment may also be necessary to ensure uniformity of product and to olfset natural variations in colour tone and intensity associated with the juice type employed in the beverage formulation. 

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