DPPH Scavenging Ability, Ultraviolet-Visible and Infrared Spectral Analyses of the Oil Extract of Diospyros Mespiliformis (Jackal Berry)

Abstract

Oils in recent times have prompted numerous researches in the bid to find suitable, edible and healthy oils for consumption or for food supplements, which is the inspiration of this research. The oil was obtained by sohxlet exrtraction of the powder of Diospyros mespiliformis (Jackal berry) seeds using n-hexane as solvent. DPPH radicals scavenging assay (with ascorbic acid as the standard), as well as UV-Visible and infrared spectral analyses were performed on the oil. The percentage yield of the oil extracted was 6.90%. Percentage DPPH radical scavenging activity of the oil at lowest concentration (5 µg/ml) was 86.32±0.06, while it was 91.43±0.07 at the highest concentration of 500 µg/ml. The trend in percentage antioxidant activity with respect to concentration of both the sample and the control in this experiment differed by producing a zigzat curve. The oil absorbed at the UV-Vis region of 380-420nm (ʎmaxs 390 nm & 417nm) and 640-700nm (ʎmax 670nm). respectively. The FT-IR spectral analysis revealed characteristic vibrations corresponding to functional groups such as C=O stretches for esters (1735.04 cm-1), C=C for alkenes bending stretch (980.64 cm-1), C≡C stretches for alkynes (2291.72 cm-1) and C-O alkyl stretching (1170.64 cm-1). The oil from Diospyros mespiliformis seeds was successfully extracted which showed promise of being a good vegetable oil, but would rather be used as food supplement/natural antioxidant packaged in capsules because of it low yield, pending toxicity being carried out on the oil.