Physiochemical characterization of <em>Coscinium fenestratum</em> G. Seed fat toward the  potential applications in cosmetics and nutritional supplements

Coscinium fenestratum, a medicinal plant native to Sri Lanka and India has been widely utilized in traditional medical practices such as Ayurveda and Siddha. Global cosmetic and nutritional industries are shifting towards plant-based feedstock, leading to the exploration of novel sources of fats and oils. C. fenestratum seed and its oil remain underutilized with no prior studies. Therefore, this study aims to characterize the seed oil of C. fenestratum by determining Fatty Acids (FA) composition as their methyl esters, chemical constituents in unsaponifiable matter, and other physiochemical properties. The oil was extracted using the soxhlet extraction method. Ash and moisture contents of seeds, Acid Value (AV), Iodine Value (IV), smoke point and thermal stability of oil were determined. Prepared fatty acid methyl esters and unsaponifiable matter were analyzed using Gas Chromatography-Mass Spectrometry method. Results indicated an oil yield of 46.94 ± 0.01% with moisture content of 4.10 ± 0.03%, ash content of 2.30 ± 0.28%, AV of 2.34 ± 0.10 mg KOH/g, IV of 8.05 ± 0.32 g I2/100g, smoke point of 202.9 ± 3.9°C, decomposition temperature of 416.88 ± 1.74°C and yield of unsaponifiable matter of 0.57 ± 0.01%. Dominant FAs, namely stearic (C18:0) and oleic (C18:1), contributed to 51.38% and 39.92% of the composition, respectively. Unsaponifiable matter revealed main constituents, including stigmasterol (1907.68 µg/g), gamma-sitosterol (1288.82 µg/g), campesterol (402.26 µg/g), fucosterol (371.57 µg/g) and squalene (129.34 µg/g). Findings of this study concluded that C. fenestratum seed fat has promising potential to be valorized in both cosmetic and nutritional supplement industries.