The rising global energy demand, alongside concerns regarding environmental deterioration due to the use of fossil fuels, has spurred extensive investigation into renewable energy alternatives. Biomass-derived biodiesel, especially from lesser-known oil sources, emerges as a promising option. This research focuses on analyzing the fatty acid methyl esters (FAMEs) derived from Kariya (Hildegardia barteri (Mast.) Kosterm) seed oil through basic catalytic transesterification using gas chromatography–flame ionization detector (GC–FID) analysis, assessing its potential as a biodiesel feedstock. Oil extraction from Kariya seeds was carried out using three solvents (n-hexane, ethanol, and a 1:1 blend of hexane and ethanol), followed by transesterification with methanol. Gas chromatography–mass spectrometry (GC–MS) and GC–FID analyses were utilized to identify and quantify FAMEs in the resulting biodiesel. The results revealed various FAMEs, including methyl myristate, methyl palmitate, methyl stearate, methyl oleate, methyl linoleate, and methyl linolenate. Significant differences in FAME composition were observed among the samples, with hexane–ethanol Kariya oil biodiesel (HE-KOB) showing the highest FAME content (76.1%). This combination of solvents exhibited synergistic effects on the composition of HE-KOB, suggesting potential optimization strategies for biodiesel production. Fourier transform infrared spectroscopy (FTIR) provided additional insights into the molecular composition of the biodiesel samples, confirming their biodiesel nature through the identified functional groups such as methyl, methylene, hydrocarbon, ester, aldehyde, and alkene. Thermogravimetric analysis (TGA) for thermal decomposition also gave an insight into FAME composition and its contribution to the degree of conversion of biodiesel to energy. These findings highlight the feasibility of utilizing Kariya seed oil as a biodiesel feedstock, emphasizing the importance of solvent selection and transesterification conditions in optimizing FAME yield and composition. This research contributes to the exploration of underutilized oil sources for sustainable biodiesel production, aligning with the global shift towards cleaner and renewable energy sources.

The shortcomings encountered from the use of conventional methods of refining draw considerable attention when it comes to the processing of edible oils. The present invention to this effect is the usage of membrane technology, which stands out as a suitable alternative, as it offers significant advantages such as minimal chemical additions, low energy consumption, and the retention of nutrients and other desired components. This paper seeks to ascertain the quality of edible oil extracted by different solvents, refined via membrane filtration. Amounts of 25 mL of crude oil sample were extracted with three different solvents (n-hexane, ethanol, and n-hexane-ethanol blend) from seeds of Hildegardia barteri (Mast.) Kosterm. and were refined using a micro-filter of pore size of 0.45 µm and an ultrafiltration membrane with 50 kDa cut off before bleaching and deodorizing to obtain table oil. Proximate composition and elemental analyses were carried out on the table oil samples produced and compared with food-grade standards. Results obtained showed 0.133–0.53% moisture content, 0.04% ash, 98.90–99.67% ether extract, 0.23% carbohydrate, and elemental compositions of 51.60–55.00% C, 6.12–6.30% H, 6.21–6.28% O, 0.01–0.02% N, and 13.0–15.0% P for edible oil samples. The findings of this study indicate that edible oil produced from the