Physiochemical and phytochemical analysis of oil from Persea american, Garcinia kola, and Annona muricata seeds

Abstract

Oils from Annona muricata (soursop), Persea americana (avocado pear), and Garcinia kola (bitter kola) seeds were extracted using n-hexane as solvent. The different oils were analyzed and evaluated to determine their physicochemical characteristics using only the n-hexane extract. The results of the physicochemical analysis showed the following values for Annona muricata (soursop), Persea americana (avocado pear) and Garcinia kola (bitter kola) oils respectively: pH: 4.10, 6.80, 5.40; Peroxide: 5.4, 8.40, 5.60 (meq/kg); Iodine: 72.74, 102.54,52.18; Specific gravity:1.79, 9.26, 0.84; Saponification: 49.09, 61.26, 16.28 (mg); Unsaponification: 51.16, 61.26, 16.28. However, three extracts (n-hexane, aqueous, and ethanol) were screened for phytochemicals such as saponins, tannins, and alkaloids and analyzed. Results of the phytochemical analysis revealed the absence of tannins and alkaloids in n-hexane extracts of the three seed oils including the aqueous and ethanol extracts of soursop but present in the aqueous extracts of both bitter kola and avocado pear. The infra-red (IR) analysis however revealed several peaks with a specific frequency of absorption for these oils, though similarities and variations between the functional groups were present.