Desert Date

Balanites aegyptiaca is a spiny, evergreen to semi-deciduous tree that reaches about ten metres and survives in some of the hottest, driest regions on earth. Its fruit is oval, about the size of a date, green turning yellowish-brown, with a thin skin and a sticky, sweet-bitter pulp around a very hard woody stone.

Inside the stone is a single oily kernel, creamy-white to pale brown, with a bitter taste when raw. The kernel is rich in oil, and it is sold dried, as a processed cake after oil extraction, or as pressed oil, often called zachun oil or lalob oil. The pulp is eaten fresh or dried, or made into a drink.

The desert date is native to the dry savannas and semi-arid lands of Africa from Senegal to Somalia and south, and across the Middle East into parts of the Indian subcontinent. It tolerates drought, heat and poor soils and is among the hardiest trees of the Sahel.

The genus name Balanites comes from the Greek balanos, meaning acorn, in reference to the shape of the fruit and stone, and the species name aegyptiaca means Egyptian, pointing to its long association with the Nile region. The name desert date is a descriptive English label for a tree of dry country with a date-sized fruit. Local names include lalob in Sudan and Ethiopia and aduwa among Hausa speakers.

Archaeological finds of Balanites stones in Egypt and Sudan show that the fruit was gathered and traded in the ancient Nile Valley, and some writers suggest it appears in tombs as an offering. The tree's oil was valued in ancient times for cooking, lamps and ointments, and it has been associated with the balsam trade of the region, although such identification of ancient products is sometimes debated.

Across the African Sahel, the desert date has long been a famine food and a source of cash. Pastoral communities eat the sweet pulp and kernels in dry years when crops fail, and women's groups press and sell the oil. In parts of West and East Africa the bark, fruit and roots are used in traditional medicines, and the crushed fruit forms a natural soap, which gave rise to the name soap berry tree.

In modern times the tree has attracted attention from researchers interested in dryland agriculture and biofuel. Studies reported by FAO-linked databases and universities in Nigeria, Uganda, Senegal and elsewhere explore its oil composition and potential as a sustainable bioresource, and the kernel oil has been tested as a source of biodiesel. It also appears in agroforestry projects meant to improve nutrition and income in dryland communities.

The kernel yields a pale yellow oil rich in unsaturated fatty acids, used for cooking in parts of Africa and in the Middle East, as well as for soap-making, lamp fuel and cosmetics. The kernels themselves are eaten after soaking or boiling to reduce their bitterness, or ground into flour or paste. The press cake is used as animal feed after processing, though it can be bitter.

The sweet pulp is eaten fresh, dried, or made into a drink and sweetener, and the leaves and young shoots are sometimes eaten as a vegetable. The tree is also planted for fodder, firewood, hedging and shade, and its seeds are used as beads.

Desert date kernels are oil-rich and also contain protein, and analyses of the oil report mostly unsaturated fatty acids. Many parts of the plant contain saponins and steroidal compounds, including diosgenin-type substances, which have been studied in laboratories for effects such as antioxidant, antimicrobial and blood-sugar activity.

Traditional medicinal claims, for instance for parasites, wounds and digestion, are mostly based on folk use and animal or test-tube studies, and robust human trials are lacking. The raw kernel is bitter because of saponins, which is one reason it is processed before eating.