Optimization and multifactor assessments of supercritical Moringa oleifera seed oil extraction

The purpose of the proposed work is to develop the statistical model and optimize the operating parameters for the extraction of Moringa oleifera seed oil using a supercritical solvent as compared to conventional hexane extraction due to rising demand for vegetable oil and stringent environmental regulations. The effect of different extracting parameters like particle size (0.50–1.00 mm), solvent flow rare (5–15 g/min), modifier percentage (0–10%), pressure (200–400 bar) and temperature (60–100 °C), and has been investigated. A three-level small-face centered composite design of response surface methodology was employed to establish the input–output statistical relationship. A modified quadratic model was developed to predict the optimal extraction conditions. The obtained results are clearly indicate that each parameter significantly influences extraction yields. The optimized conditions for maximum yield (99.9% with desirability of 1.00) were determined as temperature (98.75 °C), pressure (299 bar), particle size (1 mm), solvent flow rate (10.22 g/min), and modifier percentage (9.99%). The high R-square value suggested that the developed statistical model is able to find out the yield in the reasonable limit within the selected range of operating parameters. Thermo-gravimetric analysis also performed of oil samples reveals sequential degradation steps, showing removal of moisture, organic matter, and ash content, with residue remaining at 1015ºC. Scanning Electron Microscopy analysis revealed structural changes in the extracted seeds, exhibiting cracked layers and visible pores, suggesting that high pressure enhances extraction efficiency. Gas chromatography analysis of the extracted oil identified the presence of 78.77% unsaturated fatty acids, primarily oleic acid (74.5%), and 21.23% saturated fatty acids, including palmitic acid and stearic acid. These findings highlight the potential of supercritical solvent extraction in maximizing Moringa oleifera seed oil yield with improved efficiency.