Comparative Studies on the Physicochemical Characteristics and Lipid Contents of Desert Date (Balanites aegyptiaca (L.) Del) Kernel and Pulp Oils

Abstract

Aims: This work is aimed at investigating physicochemical parameters and compositions of fatty acid, phospholipid and sterol of desert date (Balanites aegyptiaca) kernel and pulp. Study Design: Balanites aegyptiaca fruit is one of the oldest feed-stocks in Africa of which little or no attention has been given to it. The plant plays a diverse cultural and traditional role in different societies. Therefore, it is very important to explore more about the chemical composition of the kernel and pulp oils of Balanites aegyptiaca; since it is currently attracting considerable research interest as a result of its diverse beneficial properties. Methodology: The physicochemical parameters, fatty acids, phospholipids and phytosterols of B. aegyptiaca seed and pulp oils have been analyzed and compared with the standards and that of conventional oil for easy assessment of their suitability for nutritional and industrial applications. Results: The results of some physicochemical parameters of kernel and pulp oils were acid value (26.35 and 15.60 mg KOH/g), peroxide value (3.82 and 5.90 meq/kg), saponification value (162.40 and 198.60 mg KOH/g), iodine value (55.20 and 142.50 mg of I/100 g), specific gravity (0.93 and 0.92), kinematic viscosity (2.12 and 1.65 St) and refractive index (1.41 and 1.39), respectively. The most concentrated fatty acids were palmitic acid (14.53%) < linoleic acid (35.65%) < oleic acid (38.27%) for the kernel oil while that of pulp oil were linolenic acid (8.21%) < oleic acid (16.80%) < palmitic acid (32.70%) < linoleic acid (33.56%). Arachidic, behenic, lignoceric and myristic acids were all present in small quantities with none of them recording up to 1.0% in either of the samples. Caprylic, capric and lauric acids were determined but not detected in both oils. The fatty acid composition of kernel and pulp oils contained a healthy mixture of all the types of saturated and unsaturated fatty acids. The value of polyunsaturated/saturated index (P/S) which is associated to the impact on human health was higher in the pulp oil (2.47). Phosphatidylcholine had the highest content in both oils that is 75.99 and 25.88 mg/100 g, respectively. The total values of phytosterols for kernel and pulp oils were 85.00 and 9.87 mg/100 g, respectively. Conclusion: Balanites aegytiaca kernel and pulp oils have the potential to substitute several materials used in manufacturing oil in the chemical and pharmaceutical industries. However, in order to extend usage, these oils should be refined in order to improve the colour and taste.