Optimizing ethanol-modified supercritical CO₂ extraction for enhanced bioactive compound recovery in hemp seed oil.

This work aimed to extract hemp seed oil using modified supercritical CO(2) with ethanol, while optimizing the overall process through response surface methodology. The effects of extraction temperature (30-60 °C), pressure (10-20 MPa), and time (120-300 min) on oil yield, total phenols (TPC), total tocopherols, oxidative stability index (OSI), total chlorophylls, total carotenoids, quality indices, and color were assessed. For a maximum yield of 28.83 g/100 g of fresh seeds, the oil was extracted at 50 °C and 20 MPa for 244 min. In addition, CO(2) modified with different proportions of ethanol (2.5-20%) under the optimized SFE conditions was also tested for enhancing phenolic compound extractability in hemp seed oil. The best proportion was 10% ethanol, which significantly increased the oil yield to 30.13%, TPC to 294.15 GAE mg/kg, total tocopherols to 484.38 mg/kg, and OSI to 28.01 h, without affecting the quality parameters and the fatty acid profile. Furthermore, the phenolic compounds in the extracted oils were analyzed via HPLC-DAD/ESI-MS(2). These findings indicated that CO(2) modified with ethanol enhanced the extraction of phenolic compounds, 26 of which were identified. Among these, the most abundant compounds were N-trans-caffeoyltyramine, and cannabisins A and B, with concentrations of 50.32, 13.72, and 16.11 mg/kg oil, respectively. The oil obtained by SFE with SC-CO(2) + ethanol could be valorized by evaluating its biological activities and its anti-aging, dermato-protective and antimicrobial properties for use in the cosmetics, pharmaceutical and food applications.