Annatto

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 color. 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 Caribbean islands, both fruit and tree are popularly called achiote or bija.
In Jamaica, annatto has had many uses over the centuries, including as a food dye, body paint, treatment for heartburn and stomach distress, sunscreen and insect repellent. In the Philippines, it is called atsuete, and is used as food coloring in traditional dishes.
It is a major ingredient in the popular spice blend "Sazón" made by Goya Foods.

As a food additive, annatto has the E number E160b. The fat soluble part of the crude extract is called bixin, the water soluble part is called norbixin, and both share the same E number as annatto. Annatto seed contains 4.5-5.5% pigments, which consists of 70-80% bixin.
In the United States, annatto extract is listed as a color additive "exempt from certification" and is informally considered to be a natural color. The yellowish orange color is produced by the chemical compounds bixin and norbixin, which are classified as carotenoids. However, unlike beta-carotene, another well-known carotenoid, they do not have the correct chemical structures to be vitamin A precursors. The more norbixin in an annatto color, the more yellow it is; a higher level of bixin gives it a more reddish shade. Unless an acid-proof version is used, it takes on a pink shade at low pH.
Cheddar cheese is often colored, and even as early as 1860, the real reason for this was unclear: English cheesemaker Joseph Harding stated "to the cheese consumers of London who prefer an adulterated food to that which is pure I have to announce an improvement in the annatto with which they compel the cheesemakers to colour the cheese".
One theory is that cheeses regarded as superior in the 16th century had somewhat yellow color, possibly from high levels of carotene in the grass on which the dairy cattle fed. Producers of inferior cheese added annatto to the milk to make the cheese appear better quality, thus to command a higher price.
As a food color, annatto has less tendency to oxidize than beta carotene. Solvent-extracted annatto pigment present in edible oils at even low practical use levels, markedly delays polymerization of the oils during heating, and thus delays the development of the unhealthy by-products of polymerization. Whether this effect is also present in oil-extracted annatto pigment, where annatto seeds are held in edible oil at high temperature under near vacuum or inert gas, a process that may itself induce polymerization, is not known.
The Institute of Food Technologists published a technical book dedicated to natural food colorants, including a chapter exclusively on annatto, with the most up-to-date information available, including historical and current food uses, extraction techniques, stability, analysis and pharmacology.

As an allergen
Annatto has been linked to many cases of food-related allergies, and is the only natural food coloring believed to cause as many allergic-type reactions as artificial food coloring. Because it is a natural colorant, companies using annatto may label their products "all natural" or "no artificial colors" on the principal display panel (PDP). "Natural" does not, of course, mean safe or non-toxic.
It is well known that synthetic food colors, especially some azo dyes, can provoke hypersensitivity reactions such as urticaria, angioneurotic oedema, and asthma (Michaelsson and Juhlin, 1973, Granholt and Thune, 1975). Natural food colors are scarcely investigated with respect to potential allergic properties. Annatto extract, a commonly used food color in edible fats, e.g. butter, has been tested in patients. Among 61 consecutive patients suffering from chronic urticaria and/or angioneurotic oedema, 56 patients were orally provoked by annatto extract during elimination diet. A challenge was performed with a dose equivalent to the amount used in 25 grams of butter. Twenty six per cent of the patients reacted to this color four hours (SD: 2.6) after intake. Similar challenges with synthetic dyes showed the following results: tartrazine 11%, Sunset Yellow FCF 17%, Food Red 17 16%, amaranth 9%, Ponceau 4R 15%, erythrosine 12% and Brilliant Blue FCF 14%.
These early studies indicated some natural food colors may induce hypersensitivity reactions as frequently as synthetic dyes.
Annatto is not one of the "Big Eight" allergens (cow's milk, egg, peanut, tree nuts, fish, shellfish, soy, and wheat) which are responsible for >90% of allergic food reactions. The Food and Drug Administration (FDA) and experts at the Food Allergy Research and Resource Program (FARRP) at the University of Nebraska do not at present consider annatto to be a major food allergen.

Annatto, sometimes called roucou, is a derivative of the achiote trees of tropical regions of the Americas, used to produce a yellow to orange food coloring and also as a flavoring. Its scent is described as "slightly peppery with a hint of nutmeg" and flavor as "slightly sweet and peppery".
Annatto coloring is produced from the reddish pericarp or pulp which surrounds the seed of the achiote (Bixa orellana L.). It is used as coloring in many cheeses (e.g., Cheddar, Gloucester cheese,Red Leicester, Gouda and Brie), margarine, butter, rice,custard powder ice-cream, and smoked fish. Although it is a natural food colorant, it has been linked to many cases of food-related allergies.
Annatto is commonly found in Latin America and Caribbean cuisines as both a coloring agent and for flavoring. Central and South American natives use the seeds to make a body paint and lipstick. For this reason, the achiote is sometimes called the "lipstick-tree". Achiote originated in South America and has spread in popularity to many parts of Asia. It is also grown in other tropical or subtropical regions of the world, including Central America, Africa and Asia. The heart-shaped fruit are brown or reddish brown at maturity, and are covered with short, stiff hairs. When fully mature, the fruit split open, exposing the numerous dark red seeds. While the fruit itself is not edible, the orange-red pulp that covers the seed is used to produce a yellow to orange commercial food coloring. Achiote dye is prepared by stirring the seeds in water or oil.