PHYTOCHEMICAL PROFILING OF SESAME (Sesamum indicum L.) SEED OIL USING UV-Vis AND FTIR SPECTROSCOPY

Abstract

Consumption of defective or poor-quality oils can pose health and environmental risks. Phytochemicals derived from plant oils provide natural protection to plants and confer several therapeutic and nutritional benefits in humans, including antioxidant, antimicrobial, and anticancer
activities. Conventional phytochemical analysis is often laborious, time-consuming, and less sensitive, hence the need for rapid, efficient, and non-destructive methods. Spectroscopic techniques such as Ultraviolet-Visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectroscopy offer alternatives with higher precision and minimal sample preparation. This study investigated the phytochemical constituents of sesame (Sesamum indicum) seed oil using UV-Vis and FTIR spectroscopy. Oil was extracted by cold press and n-hexane solvent methods. UVVis analysis was performed to identify conjugated dienes and phenolic compounds, while FTIR spectra were obtained to determine functional groups associated with phytochemicals. The UV-Vis
spectra revealed prominent absorption peaks at 230–280 nm and 320–360 nm, indicative of phenolic compounds, conjugated dienes, flavonoids, lignans (sesamin), and sesamol. FTIR spectra showed characteristic peaks at 1742, 2853, 2920, 1465, 1160–1100, 1600–1500, and 3400 cm⁻¹, corresponding to C=O (ester carbonyl), C–H (alkanes), CH₂ bending, C–O stretching, aromatic C=C, and O–H vibrations. These findings confirm the presence of bioactive components such as triglycerides, fatty acids, flavonoids, lignans, alcohols, and phenolic groups, which possess strong antioxidant potential.
This study establishes sesame oil as a rich source of phytochemicals with nutritional and therapeutic significance, highlighting the utility of UV-Vis and FTIR in rapid phytochemical profiling.