Selectively extracting oleoresin from Boswellia papyrifera frankincense resin by sub- and supercritical CO2 processes

In this work, selectively extracting oleoresin from the Boswellia papyrifera frankincense resin was studied by sub- and supercritical CO2 processes. GS-MS analysis was applied to identify the constituents of extracts. Sequential sub- and supercritical CO2 extraction were carried out in four stages corresponding to the pressure of 10 MPa, 15 MPa, 20 MPa, and 25 MPa at fixed temperatures of 25 ℃ and 40 ℃, respectively. The obtained oleoresins were transparent with faint yellow and the yield was 23.8% and 25.1% for sub-, and supercritical extraction, respectively. Twenty-one compounds with a relative peak area of over 1% were identified. Essential oils, alcohols, hydrocarbons, diterpenes, diterpenoids, and triterpenoids are the main chemical classes, among which the relative peak area of incensole was the highest, reaching 36% in the corresponding fraction of extracts, followed by incensole acetate with relative peak area of 17–20%. These results would benefit the depth developing applications of Boswellia papyrifera frankincense resin.