Classification of Hoi-An and Sin-Chew Agarwood by Components Analysis of VOCs Released in Heat-Treated Agarwood using TD-GCMS and Chemometric Methods

Abstract

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 via stepwise 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.

A Novel Bayes Approach to Impervious Surface Extraction from High-Resolution Remote Sensing Images

“…Bayes discriminant constructs a multivariate discriminant model based on the Bayes criterion to discriminate against the predicted object [ 45 ], which is a method to find the best division under the condition of optimizing the minimum false loss [ 46 , 47 ]. Bayes discriminant analysis has been applied to many fields and produces more accurate predictions, especially risk prediction [ 48 , 49 , 50 ], disease prediction [ 51 , 52 ] and chemometric statistical analysis [ 47 , 53 , 54 ]. However, studies applying Bayes discriminant analysis to urban impervious surface extraction are rare.…”

Uncovering the secrets of agarwood aroma according to regions and grades using a comprehensive analytical strategy

“…[7][8][9] Agarwood originates from diverse and distinct regions, although Guan-xiang, Hoi-an, and Sin-chew zones are three main production areas. The quality and chemical composition of agarwood are influenced by its specific place of origin, [10][11][12] and its multifaceted origins coupled with scarcity and escalating market demand have presented challenges in maintaining consistent quality control measures for this precious material.…”