Parametric optimization of solvent extraction of Jatropha curcas seed oil using design of experiment and its quality characterization
Adeyinka Sikiru Yusuff
Abstract
The present study investigated the individual and combined effects of extraction temperature (50–70 °C), particle size (0.6–1.0 mm), and solvent/solid ratio (8:1–10:1 mL/g) on the yield of Jatropha curcas seed oil (JCSO) using n-hexane as extraction solvent. Central composite design was used for optimization of the oil extraction process. The functional groups, purity and chemical content and fatty acid profile of the extracted JCSO were determined by FTIR, NMR, and GC-FID analyses, respectively. Optimization results showed good agreement between predicted and experimental values of oil yield with a high coefficient of determination (R2 = 0.9021 and Adj-R2 = 0.8140). The optimum extraction temperature, particle size, and solvent/solid ratio to achieve maximum oil yield of 56.69 wt.% were 69.67 °C, 0.63 mm, and 9.98:1 mL/g, respectively. The properties of the extracted JCSO compared favourably well with those reported in the literature. The extracted JCSO was made up of aliphatic, carbonyl, esters, unsaturated alkenes, glyceryl, and carboxylic groups, as revealed by the FTIR and NMR analyses. The extracted oil was more of unsaturated fatty acids with the dominance of oleic (53.27%) and linoleic (19.94%) acids.