Enhanced extraction of flaxseed oil, tocopherols, and fatty acids using supercritical carbon dioxide with ethanol: Process optimization and modelling

Abstract This study explores the extraction of flaxseed oil using supercritical CO 2 (SC‐CO 2 ) with ethanol as a co‐solvent, optimizing key process parameters to enhance oil yield and total tocopherol content (TTC). The influence of pressure (20–30 MPa), temperature (40–60°C), and CO 2 flow rate (2–6 mL/min) was analyzed using response surface methodology (RSM). The optimal conditions (20 MPa, 51°C, 2 mL/min) yielded 36.86% oil and 112.71 ppm tocopherols, demonstrating the effectiveness of SC‐CO 2 extraction. The addition of ethanol improved tocopherol and monounsaturated fatty acid (MUFA) recovery, while extraction without ethanol favoured polyunsaturated fatty acid (PUFA) retention. Gas chromatographic analysis confirmed that SC‐CO 2 extraction produced a superior fatty acid profile compared to Soxhlet extraction, preserving higher levels of α‐linolenic acid (ALA) and oleic acid. Solubility studies indicated that moderate pressure and temperature conditions enhance oil recovery. SC‐CO 2 with ethanol proved to be an efficient and environmentally friendly alternative to conventional extraction methods, producing high‐quality flaxseed oil rich in bioactive compounds. These findings support the scalability of SC‐CO 2 extraction for nutraceutical, pharmaceutical, and food applications. Future research should explore antioxidant stability and large‐scale processing feasibility to enhance industrial adoption.