Annatto (Bixa orellana)

Datasheet

Description

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Annatto (Bixa orellana) habit with immature fruits (white variety)

Annatto (Bixa orellana) bunch of fruits, maturing

Common names

Annatto, lipstick tree, achiote tree, [English]; rocouyer, rocou, roucou [French], anato, urucuzeiro, urucu, açafrao do Brasil [Portuguese]; Mzingifuri [Swahili]; 红木 [Chinese], 빅사 [Korean]; ベニノキ [Japanese]; Điều nhuộm [Vietnamese]

Species

Bixa orellana L. [Bixaceae]

Related feed(s)

Description

Annatto (Bixa orellana L.) is a tropical and subtropical perennial shrub or small tree cultivated for the orange-red pigment extracted from its seeds and used in foods, drugs and cosmetics. The spent seeds resulting of pigment extraction can be used for livestock feeding as a source of protein and energy, and small amounts of whole seeds can be included in poultry diets as sources of pigment.

Morphology

Bixa orellana is a taprooted, perennial, evergreen or deciduous shrub or small tree that reaches up to 3 m in height and has distinctive large pink flowers. The crown is round. The trunk may be up to 10 cm in diameter. The bark is pale to dark brown in colour, sometimes fissured and lenticellate. The young branches are greenish and rusty-dusty scaly, and they become dark brown and ringed at the nodes with maturity. The leaves are spirally arranged, simple and entire, petiolated. The leaf-blade is ovate in shape and 5-25 cm long x 4-16 cm broad. The flowers are bisexual, pentamerous, pinkish, whitish or purplish tinged, and approximately 4-7 cm in diameter. They form clusters at the apex of the shoots. The fruits are white, yellow or redish ovoid capsules, 2-4.5 cm long × 2-4 cm wide, the skin of the fruit has huge number of bristles. They contain many (10 to 60) obovoid and angular seeds, 4-5 mm long, bright orange-red in colour (Jansen, 2005).

Uses

The annatto tree is mainly cultivated for its pigment-producing seeds, which contain about 5% carotenoids in their outer layers. The main pigment (80% of the carotenoids) is bixin (from the taxon name Bixa orellana). Together, the oil-soluble bixin and its saponified form, the water-soluble norbixin, cover a wide range of colouring applications, and annatto seeds and extracts have been used for centuries to impart an orange and red colour to numerous products. In Europe, where its three main forms are registered as food additives E160b(i), E160b(i) and E160b(i), (EFSA, 2016), and in North America, the annatto pigment (annatto for short) is used in dairy specialties like mimolette, livarot, reblochon and cheddar, as well as for haddock colouring. In Latin America, annatto is used for dressings ("achiote"), to give an attractive red colour to meat, fish and rice dishes, and to impart distinctive flavour notes (Oliveira et al., 2012; Ulbricht et al., 2012). The pigment is also used in drugs, cosmetics (nail varnish, lipstick, self tanning cream etc.), and for textile dyeing. The oil is used as an insect repellent. After a decline during the 20th century, the use of natural colorants has been gaining renewed interest and their use increased by 35% between 2005 and 2009.

Depigmented seeds resulting from the extraction of the pigment from the seed coat can be used as a feed for livestock as source of protein and energy. Whole seeds can be used in small amounts (< 3%) as sources of pigment, notably for layer diets. However, due to the value of annatto seeds as food colouring agent, they may be too expensive to be used in livestock feeding.

Immature fruits can be used as fodder for livestock. The fruit shell has been used as a soil amendment (Pratibha et al., 2013). The seeds have many ethnomedicinal uses and the tree can be planted as a beautiful ornamental in home gardens or as a shade and nurse plant in vanilla plantations. Bixa orellana is a good live fence because cattle and goats does not consume the leaves (Jansen, 2005).

Distribution

Bixa orellana originated from tropical America and is now found (wild or cultivated) in a wide range of tropical and subtropical climates around the world. Indian populations already used annatto as a colouring and flavouring agent in antiquity. The red colour was endowed with a symbolic power and the nutty peppery flavour of annatto was much appreciated. Annatto is cultivated commercially in Kenya and on a small scale in other African countries. It has become naturalized very locally, e.g. in Kenya and Tanzania (Jansen, 2005). Annatto is found from sea level up to 2000 m altitude but does better below 800 m (Quiñones-Bravo et al., 2014; Orwa et al., 2009). Bixa orellana grows better in frost-free areas where average temperatures are of 20–26°C and average annual rainfall are 1250–2000 mm, well distributed over the year, with a marked dry season for seed ripening. In places where rainfall is not evenly distributed, irrigation may be required. Annatto grows on a wide range of soils, but does better on well-drained, neutral to slightly alkaline soils. It responds well to deep, fertile and organic matter rich soils. Annatto is a good choice on limestone, where the topsoil is only a few centimeters thick (Orwa et al., 2009; Jansen, 2005).

Processes

Bixin and norbixin are extracted from the waxy coat of the seeds in several ways. The traditional process uses water (water-extracted bixin) and consists in soaking annatto seeds in water. The other extraction media are solvent (solvent-extracted bixin and solvent-extracted norbixin (annatto C) and alkali (alkali-processed + acid precipitated norbixin; alkali-processed + not acid precipitated norbixin) (EFSA, 2016).

Forage management

Establishment

Bixa orellana can be propagated by seeds or cuttings. Seeds are sown directly (2-3 seeds per hole) in a well-prepared seedbed or in planting trays from which they will be transplanted during 3-4 months. Seeds remain viable during 1 year and readily germinate. In the case of cuttings, stems of 8 mm or more are cut and treated with a rooting hormone. After 7-9 weeks, they have produced abundent roots and are placed in pots or bags at the nursery where they stay for 3 months. After that, they can be tranplanted in the field (Jansen, 2005). It is possible to grow annatto under different agronomic systems. In Mexico, for example, annatto can be grown as a backyard tree or be integrated in the traditional "Milpa" system, in association with maize, beans and squash crops and other fruit trees, 3 m apart (Pech-Hoil et al., 2017). Annatto intended for commercial production is planted in rows 3–4 m apart, with plants spaced at 2–3 m or more within the row, depending on soil and climate (Pech-Hoil et al., 2017; Jansen, 2005). Bixa orellana starts producing fruits after 2-4 years. The tree can live up to 50 years in natural conditions, and up to 30 in commercial plantations (Quiñones-Bravo et al., 2014).

Seed yield

Annual seed yields can be in the range of 800-1200 kg/ha (0.5-4 kg per tree). In the Karnataka State (India), 2.6 t seeds/ha were obtained under good fertilizer management (Kumar et al., 2012). Up to 3–5 t seeds/ha have been reported, but, in Sri Lanka, only 625 kg/ha could be obtained (Jansen, 2005).

Environmental impact

Soil improver and windbreak

Annatto sheds a large amount of leaves, increasin the organic matter in the soil. It is reported to make an effective windbreak, even with a single row of trees (Quiñones-Bravo et al., 2014).

Nutritional aspects

Nutritional attributes

Depigmented annatto seeds have a moderate protein content (12-17% DM), few lipids (< 5%), and variable amounts of fibre (crude fibre 15-27% DM), incuding a fair amount of lignin, which may reflect natural genetic variability, differences in process, or the presence of hulls. Information is lacking about the rest of the constituents: one article (Valério et al., 2015) indicates a starch content of 32% DM while another gives a value of 67.5% DM, which is certainly excessive (the sum of all components exceeds 120%)(Senthilkumar et al., 2008). Whole annatto seeds contain a little less protein (<15% DM) and fibre (<18% DM) and a little more lipids (up to 10% DM), but data are scarce. Annatto fruit hulls are mostly fibre with little nutritive value (Bressani et al., 1983; Rodrigues Filho et al., 1993).

Ruminants

Information about the use of annatto product in ruminants is scarce. The depigmented seeds seem to be an adequate feed ingredient.

Forage

Annatoo foliage seems to be poorly palatable as the trees are planted as wind shelter and live fence because goats and cattle do not eat their leaves, which may be due to their bitter taste (Lim, 2012; Radhika et al., 2010).

Depigmented annatto seeds

Degradability

For depigmented seeds, values of in vitro DM digestibility and in sacco DM degradability (k=0.05%, obtained on buffalo) were 61.4 % and 62.4% respectively (Kumar et al., 2007). In sacco protein degradability was much lower (23.9% with k=0.05%) (Kumar et al., 2007) or similar (60.9% after 16h of incubation, cattle) (Pereira et al., 2010). In the latter case, the value was the highest among other Brazilian byproducts (Pereira et al., 2010). In cattle, the intestinal digestibility of rumen undegradable protein was 41% (Pereira et al., 2010).

Calves

In India, depigmented annatto seeds were used to replace 20% concentrate (mixture of groudnut meal, dried cassava chips and rice bran) in the diet of Jersey calves (6-9 months old). While there was no difference in intake, the annatto-based diet resulted in a lower average daily gain (330 vs 390 g/d) and higher feed conversion ratio ( 6.84 vs 5.71 kg/kg gain) (Ananthasubramaniam et al., 1981).

Use as silage

In Brazil, adding 16% annatto spent seeds to elephant grass (Pennisetum purpureum) for the production of silage improved overall silage nutritional value (Rêgo et al., 2010).

Pigs

No information could be found in the use of annatto in pig feeding (as of 2021).

Poultry

Information about the use of depigmented seeds in poultry is scarce. Whole annatto seeds can be used as a source of pigment in layer diets.

Depigmented annatto seeds

In Brazil, including up to 15% depigmented annatto seeds in the sorghum-based diet of slow-growth broilers did not affect feed intake, feed conversion ratio, or animal performance (yield of carcass, of breast and drumstick + thigh, relative weight of the liver) and improved significantly colour parameters of the meat. The sorghum-annatto diet was recommended to replace a maize-based diet in slow-growth broilers (Souza et al., 2015). In India, depigmented annatto seeds included in broiler diets could replace up to 50% maize grain without significant effect on economic traits such as body weight. However, feed efficiency decreased from 25% replacement, nitrogen retention decreased with diets beyond 50% annatto, and feed intake decreased with 75% annatto. The annatto diets caused poor pigmentation in skin and shank of broilers (Jayawickrama et al., 2010).

Whole annatto seeds

Pigment-rich whole annatto seeds have been tested in poultry and layer diets as a colouring agent for meat or egg yolk. Inclusion rates for such purposes are generally lower than 3% and higher levels may be detrimental to performance.

Most trials have targeted layer diets. In Brazil, annatto seeds could be included in sorghum-based, laying hens diet at up to 2.5% but an inclusion rate of 0.9% was enough to result in a yolk colour in eggs (Garcia et al., 2010). It was possible to add 2% annatto ground seeds to commercial diet based on maize grain and soybean meal in order to improve yolk colour (Garcia et al., 2015). However, in another study, an inclusion rate of 1.75% impaired feed intake and egg production (Carvalho et al., 2009). In Ghana, the inclusion of 7% annatto seeds in layer diets had deleterious effect on egg flavour and it was recommended to limit the inclusion of annatto seeds to 1% for acceptable colour intensity and egg flavour (Ofosu et al., 2010). In Iraq, adding annatto seeds at levels of 1, 2, and 3% to layer diets improved oxidation indicators in the egg yolk (Mohammed et al., 2018).

In Honduras, the supplementation of broiler diets with 2% annatto seeds resulted in a increased weight gain (+3%), improved the growth of beneficial bacterial strains and some litter characteristics, and it reduced the appearance of breast blisters (Moncayo, 2020).

Rabbits

No information seems available in the international literature on the utilisation of Bixa orellana products in rabbit feeding, but their use in other species indicate that whole or depigmented annatto seeds may be of value for rabbits.

Foliage

Annatto foliage seems unpalatable to ruminants (see Ruminants section) but rabbits may to some extent appreciate some bitterness in their feeds (Cheeke, 1987). It would thus be useful to design direct experiments in order to determine the value of annatto leaves for rabbits.

Seeds

As shown in the previous sections, the annatto pigment has been used safely in humans. Likewise, whole or depigmented annatto seeds have been tested successfully in several animal species. Notably, the positive effects in poultry of small amounts (< 3%) of whole annatto seeds or higher amounts (up to 25%) of depigmented seeds could perhaps be replicated in rabbits, but, again, direct experiments with rabbits would be welcome.

Fish

Annatto seeds have been tested as a feed additive (colouring agent of fish meat) in the farming of rainbow trout (Onchoryncchus mykiss) in Iran. In a first experiment, low levels (0.20-0.25 mg/kg diet) of annatto seeds were able to increase blood carotenoid content and fillet colour stability of the fish after freezing. Blood carotenoid content, growth performance and fish feed intake were positively correlated (Safari et al., 2015). In another experiment, higher levels of annatto seed powder (7.5 g/kg) in the diet or rainbow trout juveniles yielded the best growth perfomance and health parameters (blood parameters) (Heidari et al., 2019).

Nutritional tables

Tables of chemical composition and nutritional value

Annatto (Bixa orellana), seeds, depigmented

Avg: average or predicted value; SD: standard deviation; Min: minimum value; Max: maximum value; Nb: number of values (samples) used