Agriculture Reference
In-Depth Information
inserted below the disk, free, equal, with filaments 4-5 mm long; the disk is 1.5 mm in diameter,
bright yellow, nectariferous; the ovary is superior, 2 celled, with a style 1-2 mm long. Fruit is an
ellipsoid to cylindrical drupe, occasionally nearly spherical, slightly laterally compressed, 4-6.5
× 4-6.5 × 3.5-6 cm, smooth, green when ripe; pulp is bright orange, soft, juicy, sweet to slightly
bitter, with a few weak fibers, stone woody, 1 seeded. Seed usually is 2.5-4 × 1.5-2.5 × about 1
cm in size.
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Habitat and Distribution —
Three centers of genetic diversity in
Irvingia gabonensis
have
been identified to be southern Cameroon, southeastern Nigeria, and central Gabon.
Irvingia gab-
onensis
prefers moist lowland tropical forest below 1000 m altitude and with annual rainfall
of 1500-3000 mm and mean annual temperatures of 25-32°C.
Irvingia gabonensis
is better
adapted to acid ultisols in high-rainfall areas than to less-acidic alfisols; it prefers well-drained
sites. Often, 2-3 trees grow together, and in some areas it is reported to be gregarious. The plant
is indigenous to the humid forest zone of the Gulf of Guinea from western Nigeria east to the
Central African Republic and south to Cabinda (Angola) and the westernmost part of DR Congo;
it has also been found in São Tomé et Príncipe. The presence of
Irvingia gabonensis
is often
associated with former human habitation. The bigger
Irvingia
species,
Irvingia excelsa
Mildbr.,
is somewhat restricted to the rain forest of Cameroon and Gabon, while
Irvingia robur
Mildbr.
and
Irvingia smithii
Hook.f. are found co-occurring with
I. gabonensis
throughout the region.
Ethnomedicinal Uses —
All parts of the plant are used in traditional medicine. The seeds
are used as soup thickeners in West Africa. An edible oil is extracted from the seed that is also
used in cooking. The fruit of
Irvingia gabonensis
is juicy and sweet, is eaten fresh like mango,
and makes a refreshing tonic drink. Unlike the fruit pulp of most other
Irvingia
spp., which is
bitter, the pulp of ugiri has been used for the preparation of juice, jelly, jam, and wine and can
be fermented sometimes to yield an alcoholic beverage. The seed is used for the preparation of
a very slimy soup given to nursing mothers to prevent postpartum weight gain. Dika fat is solid
at ambient temperatures and has been used as a substitute for cocoa butter in beverages and in
cosmetics. The stem bark has been used for dysentery. It is used to increase male fertility and for
yellow fever, scabies, and skin diseases. The plant has been used in Laos for the treatment of liver
diseases, gonorrhea, body pain, gastrointestinal diseases, diarrhea, edema, male sexual dysfunc-
tion, and toothache.
Constituents —
Irvingia
is valued for its edible seeds and fruit pulp. The seeds yield fat
(40-75 g/100 g), called dika fat, which consists of lauric acid (20-59%), myristic acid (33-70%),
palmitic acid (2%), stearic acid (1%), and oleic acid (1-11%). The nutritive value of the kernels per
100 g edible portion is water 4 g, energy 2918 kJ (697 kcal), protein 8.5 g, fat 67 g, carbohydrate
15 g, Ca 120 mg, Fe 3.4 mg, thiamin 0.22 mg, riboflavin 0.08 mg, and niacin 0.5 mg.
1
The pulp
yields about 75% juice, which is rich in vitamin C, and wine produced from it was found to be
of good color, mouthfeel, flavor, and general acceptability. The pulp contains zingiberene and
α-curcumene, ethyl and methyl esters of cinnamic acid, and dodecanal and decanol, which are
the main flavor components and are responsible for imparting spicy-earthy, fruity, and wine-yeast
flavor notes. The nutritive value of the fruit pulp per 100 g edible portion is water 81 g, energy
255 kJ (61 kcal), protein 0.9 g, fat 0.2 g, carbohydrate 15.7 g, Ca 20 mg, P 40 mg, Fe 1.8 mg, and
ascorbic acid 7.4 mg.
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Pharmacological Studies —
The stem bark was found to have analgesic effects in tests with
mice. Aqueous extracts of the leaves have caused a reduction in intestinal motility in test animals.
A nutritional evaluation related to the performances of growth and the analysis of increasing
amounts of dika nut fat (0, 5.1%, 7.34%, and 13.48%) in young Wistar rats has shown that increas-
ing amounts of dietary
Irvingia gabonensis
fat was in correlation with the rising of myristic acid
(23.53% to 58.86%), modified cholesterol metabolism, and increased the concentration of HDL
