Sea buckthorn (Hippophae rhamnoides) oil extracted with hexane, ethanol, diethyl ether and 2-MTHF at different temperatures – An individual assessment

Sea buckthorn oil (SBO) has been individually extracted using two green solvents (2-methyltetrahydrofuran (2-MTHF) and ethanol) and two conventional solvents (hexane and diethyl ether) using accelerated solvent extraction at four different temperatures (60, 90, 120 and 150 ºC). The efficiency of the extraction was evaluated in terms of oil yield by weight difference, the quantification of α-tocopherol and β-carotene by HPLC and the evaluation of fatty acid profile by GC-FID/MS. The results were treated separately so any effect of the temperature was clearly seen for each solvent, and the fatty acid profile data was further treated jointly using a principal component analysis, as it is one of the most valued parts of sea buckthorn oil. All solvents revealed different optimal extraction temperature when in terms of oil yield; for ethanol was observed at 90 ºC (21.75%), for hexane was at 60 ºC (23.25%), for 2-MTHF was at 150 ºC (14.65%) and for diethyl ether was at 120 ºC (24.98%). The present work shows the optimal extraction temperature for SBO for each solvent studied depending on aim of the extraction.