In West Africa, a well-known local plant, the shea tree[Vitellaria paradoxa], is important as a source of nutrition for local people and an export to the West. Its fruit looks like large plums or small avocados. They yield calorie-rich oil used in preparing regional dishes and as an ingredient in the manufacturing of cosmetic.
The Multi-Purpose Tree
Oil from the smooth-skinned, egg-shaped nut of the shea fruit is a regular ingredient in cooking in the semiarid zone below the Sahara, including parts of Sudan, Ethiopia and Uganda: it adds taste and texture to porridge and is used to fry fritters, griddlecakes and many other foods.
Don Osborn, an expert in international development with a focus on African agriculture and resource management, says it's a main cooking oil in parts of West Africa.
"It's the only natural oil," he says,"that is a solid at room temperature. It facilitates it being traded; you can put it in a vessel but you don't have to have the same attention to jars as the other oils."
The fleshy pulp of the shea fruit includes moderate amounts of calcium, iron and vitamin B. The kernels of the seeds are often roasted before eating.
The wood of the tree, which is said to resist termites, was used in making the beds of ancient kings. These days it's often used to make charcoal.
The shea tree is an important source of income: It's the third largest cash crop in Burkina Faso and Ghana, where it's surpassed only by cocoa and coffee. Food industries are beginning to use the shea butter in producing pastries and sweets. The butter has also been used as a popular skin care product since the days of Cleopatra, when it was shipped to Egypt.
But there are challenges to producing more trees and to increasing the production of shea oil.
Some of them are discussed in a set of publications from the US National Research Council called Lost Crops of Africa.
The authors of the series say it's difficult to cultivate the trees, which mostly grow in the wild, although some farmers also plant the tree alongside their cereals. Unlike oil palm and olives, relatively few of the slow-maturing trees are grown in plantations.
The writers urge food scientists to improve their research on the shea tree, including its reproductive system. Well-tended trees may produce fruit within 12 years, but many others may take three and four times as long. Research could lead to advances in fruit production or to regular annual yields.
The production of shea butter is also tedious, especially for the women who process it. The pulp must rot in order to release the seed, which must be washed and dried in the sun or roasted in an oven. The seed is then broken to get the kernel, which must be ground and heated. The result is a brownish paste that must be strained or kneaded for hours to produce the fat used as shea butter.
Rather than going through all that trouble, many communities simply send the kernels to Europe for processing. There, sophisticated machinery, including hydraulic presses, remove the fat in a quicker, cheaper and more efficient way.
But some development experts say with fair pay and the technology to make processing easier, much of the work could be done in Africa and could benefit workers there. This would also add value to the shea product before export.
Paul Noren is a missionary with the Evangelical Covenant Church who, with his colleague Roy Danforth, has been documenting the shea tree and other fruits for three decades.
"It is mostly women and children picking up the fruit and nuts," he explains.
"It is laborious and tedious; I don't think the people who are doing this are getting a fair deal. I think with proper politics and economic policy and people being honest about what the producer or collector ought to deserve for their work…the price could be raised quite a bit. The price would still be very affordable to [customers] in the West."
Appropriate forms of technology that can facilitate the processing of the oil include mills and solar driers to crush, grind and dry the nuts.
The shea is one of many vegetables featured in a set of publications from the US National Research Council called Lost Crops of Africa. Food scientists say the plants are an important alternative during food shortages.
information, go the Lost Crops of Africa Volume II: Vegetables at Lost
http://www.nap.edu/catalog.php?record_id=11763 and http://search.nap.edu/nap-cgi/skimchap.cgi?recid=11763&chap=302-321