Evaluation of chemical composition of Dacryodes edulis (african pear) seed oil at different stages of fruit maturation

Abstract

Nutritional and industrial processes have increased the demand for oils and this in turn has led to the search for oils from different types of seeds for possible development and use. It is in this vein that the fruit pulp of Dacryodes edulis was extracted with n-hexane (soxhlet extraction at 65°C). The proximate composition, antinutrient and mineral content of freshly harvested D. edulis fruit pulp from 4 weeks after anthesis (WAA) to fruit maturation were assessed in this study. Data obtained for the  proximate composition at matured stages of fruit development revealed high amount of fat (53.4 ± 1.35%; moisture (47.2 ± 1.20%); crude protein (17.0 ± 0.48%); carbohydrate (21.70  ± 0.98%); low crude fiber (1.60 ± 0.75%) and ash content (8.0 ± 0.81%) which contained higher amount of minerals  such as of Fe (62.71 ± 0.34 ppm), Mn (21.05 ± 0.18 ppm), Cu (10.12 ± 0.17 ppm)  and low in Pb (6.17 ± 0.13 ppm), Ni (1.8 ± 0.56 ppm), Ca (0.41± 0.07%), Cr and Cd were not detected throughout the development stages at 20 WAA as compared to immature stages of 4, 6, 8, 10, 12, 14 and 16 WAA. The level of antinutrient factors are oxalate (5.2 ± 0.91 mg/100 g); phytate (0.32±0.02 mg/100 g) and cyanogenic glycosides (0.14 ± 0.02) which recorded lower content, except tannins (82.11 ± 0.33) mg/100 g which recorded significant (p < 0.05) higher content at 20 WAA when compared with immature stages in 4, 6, 8, 10, 12, 14 and 16 WAA. This study revealed the nutritional profile of the fruit pulp as good sources of plant protein, carbohydrate and fat, with a reduction in the level of some anti-nutrients in matured fruits which are potentials that could be exploited by food and pharmaceutical industries.   Key words: Dacryodes edulis, proximate, antinutrient, n-hexane, anthesis.