Agarwood can be divided into resinous heartwood from the Hoi-An zone and Sin-Chew zone. Traditionally, an experienced human grader classifies agarwood by odor. However, sensory errors can follow from subjectivity, poor reproducibility, and time consumption during manual work. In this study, agarwood samples were heat-treated to release volatile organic compounds (VOCs), which were analyzed using the thermal desorption – gas chromatograph mass spectrograph (TD-GCMS) method and chemometrics analysis. The classification of agarwood was then identified. Sesquiterpenes and other aromatic compounds were the main compounds of heat-treated VOCs. Twenty-six characteristic compounds were screened viastepwise regression. Fisher discriminant analysis and Bayes discriminant analysis were conducted, based on the 26 compounds, to classify the agarwood samples. Discriminant functions of the two analysis methods were obtained.The results showed that it is feasible to use the TD-GCMS method combined with chemometrics analysis to analyze VOCs from heat-treated agarwood instead of experienced graders to classify the agarwood samples as being from either the Hoi-An zone and Sin-Chew zone. This study also provides a way to classify unknown samples by odor through 26 characteristic compound’srelative peak area and the discriminant equations, offering the possibility of testing an unknown sample’s cultivation region.
Reference: Jia, D. and S. Yi (2018). “Classification of Hoi-An and Sin-Chew Agarwood by Components Analysis of VOCs Released in Heat-Treated Agarwood using TD-GCMS and Chemometric Methods.” BioResources 13(2): 2916-2931.