Pigments annatto

The colorant is prepared by leaching the annatto seeds with an extractant prepared from one or more approved, food-grade materials taken from a hst that includes various solvents, edible vegetable oils and fats, and alkaline aqueous and alcohoHc solutions (46,47). Depending on the use intended, the alkaline extracts are often treated with food-grade acids to precipitate the annatto pigments, which ia turn may or may not be further purified by recrystallization from an approved solvent. Annatto extract is one of the oldest known dyes, used siace antiquity for the coloring of food, textiles, and cosmetics. It has been used ia the United States and Europe for over 100 years as a color additive for butter and cheese (48—50). 

Annatto is a colored pigment that is extracted from the Central and South American plant Bixa orellana. The color comes from the resinous outer covering of the seeds of the plant, which is composed of the carotenoid pigments bixin and norbixin and their esters. The central portion of those molecules is the same as that of the molecule beta-carotene, and the yellow-orange color of annatto comes from the same physical chemistry origins as the orange color of beta-carotene. 

Bixin, a diapocarotenoid with a cis configuration at the carbon 9 and two carboxylic groups (one methylated), accounts for more than 80% of the total carotenoid content in annatto seeds, and has only been encountered to date in these seeds. The amount of red pigments in annatto seeds varies from 1.5 to 4%, depending on the variety. Bixin is the main pigment in commercial annatto powder... 

Colorant containing annatto and Ca caseinate as carrier mixed with water to be added directly to cheese milk yielding uniform colored cheese mass Water-dispersible beadlet of p-carotene is mixed with oil to attein composition that remains stable even in presence of polyphosphates and with antioxidant action even in absence of ascorbic acid Blending carotenoid pigment and soybean fiber (wifii tomato juice) as effective ingredient for dispersion stability... 

Bouvier, R, Dogbo, O., and Camara, B., Biosynthesis of the food and cosmetic plant pigment bixin (annatto). Science 300, 2089, 2003. 

Dried or freeze dried samples can be extracted with water-immiscible solvents such as EtOAc or diethyl ether. For quantitative extraction, dried samples are preferably rehydrated at different times for example, 5 to 10 min for dried mangoes, 30 min for lyophihzed red peppers and pasta. Rehydration is followed by extraction with acetone or MeOH. Bixin and norbixin from a mix dry powder of annatto and com can quantitatively be extracted with MeOH followed by acetone. In order to improve pigment recovery, extruded foods require pre-digestion with enzymes to liberate the pigment from the matrix. ... 

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... 

Figure 11.8 Structures of c/s-bixin and norbixin, apocarotenoid pigments in annatto.

Annatto Extracts occur as dark red solutions, emulsions, or suspensions in water or oil or as dark red powders. The extract is prepared from annatto seed, Bixa orellana L. (Fam. Bixa-ceae), using a food-grade extraction solvent. Bixin is the principal pigment of oil-soluble Annatto Extracts. Norbixin is the principal pigment of alkaline water-soluble Annatto Extracts. Commercial preparations are usually mixtures of bixin, norbixin, and other carotenoids. 

Annatto is classified as El 60(b). It is extracted from the seeds of the tree Bixa orellana which grows in America, India and East Africa. The extract is a mixture of two pigments, bixin and nor-bixin. Bixin is oil soluble, whereas nor-bixin is water soluble (it is one of the two water soluble carotenes - the other is crocin), and both of the pigments are diapo-carotenoids. Annatto has long been used as a food colouring and also has some uses as a food flavouring. 

Annatto is the seed of the bush, Bixa orellana, which is mainly found in Central and South America and in East Africa. Traditionally, annatto seeds are also used as a spice, often blended with other ingredients before addition to soups and meat dishes. The seeds grow in large clusters of capsular fruits that upon harvesting are dried in the sun, cracked open and taken out by hand. The basic colour pigment is bixin, a natural carotenoid that is found in the thin resinous coating of the seed, ft can be extracted in different ways to yield oil-soluble extracts, oil suspensions or water-soluble extracts. 

By extracting the annatto seeds with water and potassium hydroxide, bixin is converted into the water-soluble pigment norbixin. Water-soluble solutions... 

Acid stability of the colour is required in low pH applications like soft drinks and many confectionery products. Alkaline formulations of chlorophyll and annatto colours are the most sensitive, and acid-proof formulations should be preferred. However, increased acid stability may be achieved if the annatto pigment noibixin is able to bind to protein, e.g., fruit pulp in fruit based beverages. 

Pressures from 3,000 to 7,000 p.s.i. and temperatures from 40-55 "C were used to study the extraction of annatto seed pigments by supercritical COj. Maximum solubilities were 0.003 for pure bixin and 0.26 mg/g COj for annatto seed pigment. (7) SFE with COj was used to fractionate oat lipids into polar and nonpolar components, so aqueous phase interactions could be studied. 

In comet assays, no mutagenic activity was observed in rats fed a diet containing up to 1000 ppm annatto (4.23 g/kg bixin daily) for 2 weeks before or 8 weeks after treatment with diethylnitrosamine (Agner et al. 2004, 2005), and no enhancement in DNA breakage was detected in liver or kidney from mice treated with annatto pigments at doses up to 351 mg/kg daily for 21 days (Fernandes et al. 2002). 

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