Targeted analysis of sea buckthorn oil extracted by accelerated solvent extraction technique using green and conventional solvents

Sea buckthorn oil (SBO) was extracted using accelerated solvent extraction with two green solvents (ethanol and 2-methyltetrahydrofuran), and two petroleum-based solvents (hexane and diethyl ether) at four different temperatures (60, 90, 120 and 150 °C), using one extraction cycle at 103.42 bar, 10 min static time, 5 min preheating and 30% flushing volume. β-carotene and α-tocopherol were quantified jointly using HPLC-UV/VIS and the fatty acid profile was analyzed using GC-MS. Extraction yield was also measured and the data was compared to a conventional extraction using Soxhlet. The extraction with ethanol achieved significantly higher concentrations of β-carotene in the final oil (1.67 mg/g oil) compared to the results of any other solvent (e.g. 1.23 mg/g oil for hexane ASE) or to the conventional extraction (1.27 mg/g oil). However, the use of green solvents led to the dragging of unwanted polar compounds (sugars), leading to lower oil yield values after purification.