Extraction of agarwood (Aquilaria crassna) oil by using supercritical carbon dioxide extraction and enzyme pretreatment on hydrodistillation

Abstract

Agarwood (Aquilaria crassna) is a fragrant wood containing economically important essential oil. It has been traded for use as incense, perfume and traditional medicine. In this study, the effect of three different methods for extraction of agarwood oil and the chemical compositions of extracted agarwood oil were studied. Conventional hydrodistillation method had two major disadvantages namely; long extraction time of about 5 days and high energy consumption with low yield (0.075% w/w). Pretreatment of agarwood with technical enzymes before hydrodistillation affected the extractability of essential oil positively (0.20% w/w). Extraction of agarwood oil using supercritical carbon dioxide at 600 bar resulted higher yield (0.47% w/w) compared to hydrodistilation at distinct shorter extraction time of 3 h and process temperature (85°C). Analyzing of the extracts using Gas Chromatograph/Mass Spectrometer (GC/MS) had shown that the composition of essential oils differed from each other. The major compounds in essential oil from hydrodistillation were selina-3,7(11)-diene (17.21%), δ-selinene (12.36%), 1,3,5-trimethyl-6-methyldiene-tricyclo [3.2.1.0(2,7) [oct6-3-en-8exo-ol (10.26%) and 4a,5-Dimethyl- 3-(1-methyldiene)-4,4a,5,6,7,8-hexa hydro-2(3H)-napthalene (9.6%). Pretreatment of agarwood with technical enzymes resulted aristol-9-en-8-one (28.77%), β-guaiene (14.94), guaia-3,9-diene (14.32%) and 7,7-dichlorobicycl0 [3.2.0] hept-2-en- 6-one (7.58%) as the principal substances. For supercritical carbon dioxide (ScCO2) extraction (600 bar, 85°C, 3h) of agarwood was three substances; furoscrobiculin B (27.98%), furosardorin A (19.07%), and bicyclo[4.4.0]des-5-ene, 1,5-dimethyl-3-hydroxy-8-(1-methylene-2-hydroxyethyl-1) (18.68%) as the main substances in agarwood oil.