Onwuzuruike, U. A..; Eni, A. O. ; Uluocha, M. D.; Edima-Nyah, A. P., Eleumo, K. G., & Chidiebere, A. G. 2025

Traditional extraction of Ugba seed oil from raw seeds offers limited insight into the effects of pre-treatment; therefore, this study examined how different pre-treatment procedures influence the yield and chemical properties of Ugba seed oils. The seeds were subjected to different pre-treatments, such as cooking and roasting, and later blended into powder. Oil was extracted from each pre-treated powder by deploying the Soxhlet extraction protocol. The recovered oil was analysed for yield, quality attributes, chemical composition, and phytochemical contents. The oil yield for raw Ugba seeds was 46.88%, 42.38% for cooked Ugba seeds, and 58.19% for roasted Ugba seeds. The results showed peroxide values ranging from 2.51 to 6.84 meq O2/kg fat, free fatty acids ranged from 0.25 to 7.37%, while thiobarbituric acid values ranged from 0.03 to 1.84 mg/g. The iodine value, saponification value, unsaponifiable matter, smoke point, and viscosity values exhibited significant differences (p<0.05) among themselves, ranging from 85.10 to 124.55 g of I2/100 g, 176.45 to 211.37 mg KOH/g, 0.84 to 2.09%, 191.86 to 233.00°C, and 15.55 to 35.13 Pa.s, respectively. Flavonoids ranged from 0.01 to 1.40 CE mg/g, tannins from 0.00 to 1.02 mg/100 g, saponins from 0.00 to 4.49 mg/100 g, and alkaloids from 0.00 to 8.82 mg/100 g. Roasted seeds recorded the highest percentage oil yield, but with oil products of lower chemical stability, while raw seeds provided higher quality oil. This underscores the critical role of pre-treatment in optimising oil yield and quality.