Physico-chemical characteristics and fatty acid profile of desert date kernel oil in Uganda.

Abstract

The desert date (Balanites aegyptiaca (L.) Del.) is an indigenous fruit tree, common in the arid and semi-arid lands of Africa. Its fruits, available in the height of the dry season, contain edible pulp which is an important food for both humans and livestock. Balanites kernel is a source of highly regarded edible and medicinal oil. Both the fruits and oil are trade items in the west Nile sub-region of Uganda. Because of its growing importance as a source of food and income for dryland communities, an assessment of the physico-chemical characteristics and fatty acid profile of kernel oil in Uganda was carried out. Balanites fruit samples were collected from Katakwi, Adjumani and Moroto districts; representing the Teso, West Nile and Karamoja tree populations, respectively. Balanites kernels constituted 19.5% of the nuts, and kernel oil yield was 44.5% (v/v or w/w). The oil was light yellow with a refractive index of 1.46 at 20 oC and viscosity of 15.75 - 22.60 cSt at 40 oC. The saponification value of the oil was 186.28 mg KOH g^-1; while the acid value was generally low (1.33 -1.95 mg KOH g^-1). Iodine value ranged from 98.20 to 103.32 I₂g 100 g^-1. Four major fatty acids; linoleic (39.85%), (oleic 25.74%), stearic (19.01%) and palmitic (15.40%) were found in Balanites oil. This gives a high percentage of the nutritionally beneficial unsaturated fatty acids (65.6%). Balanites kernel oil is a good source of essential unsaturated fatty acids. Attempts should be made to increase its utilisation through improved processing and packaging for the benefit of rural and peri-urban communities.

Key Words: Balanites aegyptiaca, fruits, nutrition, unsaturated fatty acids, Uganda