Supercritical CO2 extraction and component analysis of anthocyanins from Lycium Ruthenicum Murray

Lycium ruthenicum Murray is rich in bioactive anthocyanins. However, the thermolabile nature of anthocyanins restricts conventional extraction technologies. This study employed a mild and eco-friendly supercritical CO₂ extraction to isolate anthocyanins, determined optimal conditions to validate the feasibility of green extraction for preserving structural integrity. The best conditions were 35 °C, 20 MPa, 13 L/h CO₂ flow rate (measured at 5 MPa, 20 °C to 32 °C), corresponding to an estimated 1.56 kg/h mass flow rate and a solvent-to-feed ratio of 9.5 kg/kg, extraction time of 55 min and 0.3 % glacial acetic acid as co-solvent. Under these conditions, the process achieved a total extraction yield of 8.0 %, with the overall anthocyanin yield reaching 0.0880 mg/100 g and petunidin-3-(p-coumaroyl)-rutinoside-5-glucoside yield at (0.0645 ± 0.0092) mg/100 g. The structural integrity and molecular identity of the extracted anthocyanins were detected by HPLC and HRMS, showing consistent retention time and precise molecular weight matching the reference compound. This scalable low-temperature process significantly minimizes thermal degradation and solvent residues, thereby facilitating industrial utilization of Lycium ruthenicum Murray through high-purity anthocyanin extracts.