Wednesday, 13 January 2016

Ackee


The ackee, also known as achee, ackee apple or akee (Blighia sapida) is a member of the Sapindaceae (soapberry family), as are the lychee and the longan. It is native to tropical West Africa in Cameroon, Gabon, São Tomé and Príncipe, Benin, Burkina Faso, Ivory Coast, Ghana, Guinea, Guinea-Bissau, Mali, Nigeria, Senegal, Sierra Leone and Togo.
The scientific name honours Captain William Bligh who took the fruit from Jamaica to the Royal Botanic Gardens in Kew, England in 1793 and introduced it to science. The common name is derived from the West African Akan akye fufo.
The fruit was imported to Jamaica from West Africa (probably on a slave ship) before 1778. Since then it has become a major feature of various Caribbean cuisines, and is also cultivated in tropical and subtropical areas elsewhere around the world.
Botany
Ackee is an evergreen tree that grows about 10 metres tall, with a short trunk and a dense crown.
The leaves are paripinnately compound,15–30 centimetres (5.9–11.8 in) long, with 6–10 elliptical to obovate-oblong leathery leaflets. Each leaflet is 8–12 centimetres (3.1–4.7 in) long and 5–8 centimetres (2.0–3.1 in) wide.
The inflorescences are fragrant, up to 20 cm long, with unisexual flowers that bloom during warm months. Each flower has five greenish-white petals
The fruit is pear-shaped. When it ripens, it turns from green to a bright red to yellow-orange, and splits open to reveal three large, shiny black seeds, each partly surrounded by soft, creamy or spongy, white to yellow flesh—the aril. The fruit typically weighs 100–200 grams (3.5–7.1 oz).
Toxicity
The unripened or inedible portions of the fruit contain the toxins hypoglycin A and hypoglycin B. Hypoglycin A is found in both the seeds and the arils, while hypoglycin B is found only in the seeds. Hypoglycin is converted in the body to methylene cyclopropyl acetic acid (MCPA). Hypoglycin and MCPA are both toxic. MCPA inhibits several enzymes involved in the breakdown of acyl CoA compounds. Hypoglycin binds irreversibly to coenzyme A, carnitine and carnitine acyltransferases I and reducing their bioavailability and consequently inhibiting beta oxidation of fatty acids. Beta oxidation normally provides the body with ATP, NADH, and acetyl CoA which is used to supplement the energy produced by glycolysis. Glucose stores are consequently depleted leading to hypoglycemia. Clinically, this condition is called Jamaican vomiting sickness. These effects occur only when the unripe fruit is consumed.

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