Abstract:
Objective Aquilaria sinensis is a rare and endemic medicinal plant in China. While its agarwood resources are scarce, non-resinous organs such as flowers and leaves are abundant. The aim is to analyze the differences in volatile components of the flowers, leaves and processed products (tea) of A. sinensis, clarify the influence mechanism of organ characteristics and processing techniques on volatile components, and provide support for the differentiated development of A. sinensis resources.
Method Flowers and leaves from the same A. sinensis plant were used as raw materials, and A. sinensis tea was prepared via the traditional Oolong tea process. GC-IMS was employed to detect the volatile components of A. sinensis flowers, leaves, and tea with optimized headspace and chromatographic conditions. Combined with LAV software and the Clustvis platform, qualitative analysis of components and principal component analysis (PCA) were performed based on the peak volume data of volatile components.
Result A total of 90 volatile components (83 known ones) were detected from A. sinensis flowers, leaves, and tea samples using GC-IMS technology, mainly including esters (24.10%), alcohols (21.69%), followed by aldehydes (18.07%) and ketones (14.46%). The number of detected components was 30% higher than that extracted by GC-MS technology, and isomers such as 2-hexenal and nonanal could be distinguished. The volatile components of A. sinensis flowers were dominated by short-chain aldehydes and alcohols such as tert-butanol and nonanal; leaves were rich in green leaf volatiles including 2-hexenal and diethyl sulfide; tea was enriched with heat-processed derived components such as (E, E)-2, 4-heptadienal dimer and 2-ethyl-3-methylpyrazine. In the PCA, the cumulative contribution rate of principal component 1 and principal component 2 reached 93.8%, which could effectively distinguish A. sinensis flowers, leaves, and tea, realizing the rapid identification of the three types of samples.
Conclusion GC-IMS technology has significant advantages in the detection of volatile components of A. sinensis, with higher detection efficiency than GC-MS. This study clarifies the differentiated development directions of A. sinensis: flowers for natural floral essence, leaves for herbal tea, and tea for functional tea. It provides a scientific basis and technical route for the efficient utilization of non-resinous organs of A. sinensis and the accurate analysis of medicinal plant components.