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

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 o C and viscosity of 15.75 - 22.60 cSt at 40 o C. 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 I 2 g 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.