Annatto as Food Colouring
In Australia it is commonly used in cereals, snack foods, dairy foods including yoghurts, icecreams and cheeses, snack foods and a wide range of other foods. It can also be called bixin and norbixin.
It is the only natural colour that has so far as been found to cause as many adverse intolerance reactions as artificial colours and to affect more consumers that artificial colours. It has also been associated with rare allergic reactions. Adverse reactions to annatto can include skin, gastrointestinal, airways and central nervous system reactions. Refer also to Annatto Benefits and Precautions.
Using annatto for colour has been a traditional characteristic of Gloucester cheese since the 16th century when producers of inferior cheese used a colouring agent to replicate the orange hue achieved by the best cheesemakers. During the summer months the high levels of carotene in the grass would have given the milk an orangey colour which was carried through into the cheese. This orange hue was regarded as an indicator of the best cheese and that is why the custom of adding annatto spread to other parts of the UK, with Cheshire and Red Leicester cheese, as well as coloured cheddar made in Scotland, all using this natural dye.
Many Latin American cuisines traditionally use annatto in recipes of Spanish origin that originally call for saffron; for example, in arroz con pollo, to give the rice a yellow colour. In Venezuela, annatto (called locally onoto) is used in the preparation of hallacas, perico, and other traditional dishes. In Brazil, both annatto (the product) and the tree (Bixa orellana L.) are called urucum, and the product itself may also be called colorau.
In the European Union and Australia, annatto has the E number E160b. In the United States, annatto extract is listed as a colour additive “exempt from certification” and is informally considered to be a natural colouring. Foods coloured with annatto may declare the colouring in the statement of ingredients as “coloured with annatto” or “annatto colour.”
The yellow to orange colour is produced by the chemical compounds bixin and norbixin, which are classified as carotenoids. The fat soluble colour in the crude extract is called bixin, which can then be saponified into water soluble norbixin. This dual solubility property of annatto is rare for carotenoids. The seeds contain 4.5-5.5% pigments, which consists of 70-80% bixin. Unlike beta-carotene, another well-known carotenoid, annatto based pigments are not vitamin A precursors. The more norbixin in an annatto colour, the more yellow it is; a higher level of bixin gives it a more orange shade.