Extraction and Characterization of Oil from African Locust Bean (Parkia biglobosa) Seed

Abstract

The extraction of oil from African locust bean seeds was carried out in this work. Standard procedures were followed to determine the yield present in the oil feed stocks using n-hexane in a Soxhlet extraction apparatus. Analyses were carried out to determine their proximate compositions and physicochemical characteristics. The determination of the functional groups and fatty acid compositions present in the extracted oils was also carried out using Fourier Transform Infrared Spectrophotometry (FTIR) and Gas Chromatography Mass Spectrophotometry (GC-MS) respectively. The results revealed that African locust bean seed has higher oil yield, crude fat, crude protein, ash content, crude fibre, moisture content than some other seeds such as Date palm seed with the exception of the carbohydrates content. Similarly, African locust bean seed oil which was yellowish brown in colour contained higher acid value, iodine value, peroxide value, free fatty acid with the exception of saponification value and specific gravity in comparism. Result from the FTIR analysis shows that 15 peaks were noticed in African locust bean seed oil, indicating the presence of various functional groups such as OH, C-H, C=C, C=O, C≡ C and C — N. Similarly, the GC-MS result also reveals that there are 6 dominating fatty acid compounds present in locust beans seed oil in relation to their relative weight composition abundance. In locust bean seed oil, linoleic acid stood out as the fatty acid compound with the highest weight composition of 31.9% having a relatively high degree of unsaturation. Furthermore, capric acid and lauric acid were found in this oil.  Judging from all the results in this work, it can be deduced that African locust bean seed oil may serve as better alternative oil for consumption and in large-scale production of lubricants, cosmetics, paints, and hydraulic brake fluid.