Not for nothing has the marula (Sclerocarya birrea) been dubbed the “food of kings.”
In the giant triangle from Cape Verde in West Africa, to the Horn of Africa in the east, and to the Cape of Good Hope in the south, its prized fruits and macadamia-like seeds are in demand.
Many Africans consider a gift of marula nuts a sign of friendship.
In some societies, the tree ranks as a major food supplier, its economic and social importance being such that they are said to have a “marula culture”.
Legends abound on the multiple uses of the tree, the bark, the leaves, fruit, nut and kernels.
Most well-known as the fruit that “drives elephants mad” when dropped to the ground and lightly fermented, marula is a much-loved tree in the veld in Africa. It was a dietary mainstay in South Africa, Botswana and Namibia throughout ancient times.
Presently marula is considered a subtropical crop of limited adaptation but considerable promise.
Both its adaptation and commercial possibilities may soon be much clearer because the rising popularity of a fruit-juice drink and a liqueur has stimulated horticultural interest all across Southern Africa.
Although the fruit’s clingstone quality means that it is best for processing into such things as juice, jelly, and beverages, its pleasant apple-like odour and litchi-pineapple-guava flavor, not forgetting its nutrient content, would seem to justify confidence in its prospects for much wider use.
How well the southern marula will do in the other parts of Africa is presently unknown.
Possibly it will perform in stellar fashion. Here are likely scenarios.
Humid Areas: Uncertain prospects. The southern subspecies appears ill-adapted to high humidity.
The northern counterpart, however, is a possible new resource for hot and hard conditions.
Already, it is being planted quite extensively in Zambia.
Dry Areas: Excellent prospects. Marula tolerates saline water and grows with vigour in desert heat. The trees continue bearing even during droughts, although dryness makes the fruits somewhat smaller. Once established, however, the trees are almost never killed by desiccation.
Upland Areas: Uncertain prospects. The plant is somewhat frost-tender, but there may be locations where it safely fits the climate.
How well this plant will perform and how well its fruit and nut will be accepted in lands beyond Africa is unknown and uncertain.
Nonetheless, small-scale trial plantings are warranted in locales to which it is suited.
Marula fruit pulp serves as a flavourful natural base for fruit soft drinks, nectars, and teas; alcoholic beverages such as brandies, liqueurs, beer, wines and punches.
Marula is already also appearing in commerce in the form of juices, jams, jellies, puree, and liqueur.
Marula primarily provides fruits and nuts, but those are really just a start.
Consider the following.
The fruits are eaten fresh in many parts of subtropical Southern Africa.
They are sometimes cooked.
The juice not only makes an agreeable drink; it is often boiled down into thick black syrup, used mainly for sweetening sorghum gruel.
The flesh can also be dried and stored for later use, when it is typically added to cereal porridge.
Drinks made from marula are everywhere popular.
Many places boast of their local marula beer. In southeastern Zimbabwe, for example, it is called “mukumbi” and it is much liked.
In Swaziland, a very potent marula drink is so popular it drastically affects the local breweries’ beer sales during the fruiting season.
In Namibia there is an official marula wine season during which no one is allowed to carry traditional weapons and crimes are punished with double the usual punishment.
Marula nuts are used to flavour dishes of meat, greens, and porridge as well as being pounded into flour and pressed into cakes.
The kernels can also be used like walnut or pecan in baking.
They are especially used to provide protein and dietary energy during the “hungry season” — the time before the staples are harvested.
The oil extracted from the kernel has a fatty acid profile similar to olive oil.
It is not only high in monounsaturation, but is relatively low in tocopherol and thus has exceptional stability.
On the basis of its chemical makeup, marula oil is well suited for use in frying, cosmetics, or coatings on foods such as dried fruit. Presently, it is too expensive to succeed as common cooking oil, but might find a niche market as a specialty salad oil.
It may also find greater use in cosmetics; it is “non-drying” and reportedly seems to have properties that combat the aging of skin. Because of its reputed antibacterial action marula oil is used to treat wounds and burns.
It is also used as a preservative for biltong.
Stock farmers love having marula trees dotting their property.
This big, leafy tree provides great shade and its fruit, leaves, and bark make excellent fodder, especially welcome during times of drought.
For wildlife, the marula is also important, constituting a living, renewable pantry for hordes of herbivores and omnivores — from elephant, rhinoceros, giraffe, and kudu to warthog and hedgehog. Baboons are particularly fond of picking up the ripe fruit scattered under the trees.
Flowers produce nectar in quantity, making the tree an important resource for beekeepers.
The honey is light-coloured with excellent flavour.
The wood hardens as it seasons, eventually becoming durable and strong.
Although dirty white, with red and brown streaks, it turns a pretty pink when polished. Carvers make it into drums, stamp-blocks, troughs, spoons, stools, bowls, and more.
Because it is easy to work and does not splinter, it was once popular for toilet seats — so popular in South Africa that the tree almost became a threatened species.
Although marula fruit pulp is an important source of micronutrients, vitamin C is what makes it nutritionally interesting. The flesh commonly contains 180 mg vitamin C per 100g, but the concentrations can go even higher.
In this regard, the marula outshines orange, grapefruit, and lemon.
At 2mg per ml of juice (about the amount of juice found in one fruit), it is an especially important source of this essential nutrient.
Carbohydrate levels of between seven and 16 percent have been recorded in the fruit pulp.
The carbohydrate consists mainly of sucrose, with smaller quantities of glucose and fructose.
The acidity is due mainly to vitamin C (ascorbic acid) and citric acid.
In addition, marula has something oranges lack — a good-tasting nut.
Rich in food energy, the kernel normally contains around 700 calories per 100 g and surpasses the nutritive content of globally famous nuts such as almonds, chestnuts, and hazelnuts.
Because of their fine taste, marula nuts are described as a delicacy. Their fat, protein and mineral contents make them a useful dietary supplement during winter or droughts.
They are exceptionally nutritious, with 28-31 percent protein, 56-61 percent oil, 2.02 percent citric acid, malic acid, and sugar, phosphorus, magnesium, copper, zinc, and B vitamins (thiamine and nicotinic acid).
Protein levels of 54-70 percent have been reported for de-fatted nutmeat.
• Next week: Horticulture, harvesting and handling, limitations and next steps.
Sources: UN, FAO, NAS, IIED, World Bank, Forum for Food Security in Southern Africa, How Stuff Works, Wikipedia, Rural 21, Natural News, Agricultural Research Council (SA), Moringa News, American Agricultural Economics Association, New Era, SciDev.net, Agricultural Union, Agronomic Board, Nourishing the Planet, Meitzner and Price, own.