Comparative Study on Extraction of Essential Oil from Agarwood Bark Using Subcritical Water and Conventional Methods

Abstract

This study compared the quantity and quality of essential oil extracted from agarwood bark using subcritical water (Sub-CW), Soxhlet, and hydro-distillation (HD). From this study, Sub-CW is considered the most practical method for extraction of essential oil from agarwood bark as it produced the highest percentage of oil yield (4.89%) at the shortest extraction period (5 min) as compared to the Soxhlet (2.19%, 6 h) and HD methods (0.15%, 12 h). The highest oil yield was collected at a Sub-CW extraction temperature of 135 °C. From GC analysis, oil extracted using Sub-CW contains three oxygenated sesquiterpenes, which are epoxybulnesene, caryophyllene oxide, and kusunol.