Physicochemical Properties of Cold-Press Sesame (Sesamum indicum L.) Seed Oils and Their Defatted Residues

This study aimed to examine the physicochemical properties, fatty acid composition, differential scanning calorimetric (DSC) profile, and Fourier transform infrared (FTIR) spectral properties of sesame oils extracted from ANKSE3 and UMA cultivars of Sri Lanka. Cold press extraction of the raw seed yielded good quality oil and edible grade defatted residues. Proximate compositional analysis showed that fat was the main constituent of the raw seeds regardless of the cultivar, while protein was the predominant constituent of the defatted residues. The color intensity of the oil of the UMA cultivar was stronger than that of ANKSE3. High iodine values and lower saponification values were observed in the oils of both cultivars. Both oils contained approximately 85% unsaturated fatty acids (USFAs), and 15% saturated fatty acids (SFAs), with oleic and linoleic acids being the most abundant. The existence of triacylglycerols (TAGs) of varying melting temperatures was clearly exhibited by distinct exothermic and endothermic peaks of the DSC curves. The occurrence of organic functional groups like alkanes, alkenes, fatty esters, etc. was clearly demonstrated by FTIR spectra of sesame oils. The findings highlighted the superiority of sesame oils of ANKSE3 and UMA as nutritious oils due to their high content of USFAs, and defatted residues of sesame as a good source of alternative vegetable protein for value-added product formulations.