Volatile Composition and Odor Characteristics of Absolutes from the Dried Aerial Parts of Eleven Aster Species

Comparative information on the chemical and odor characteristics of absolutes from Aster species remains limited. This study compared the yield, volatile composition, and odor characteristics of absolutes prepared from the dried aerial parts of eleven Aster species native to Korea. Odor intensity and electronic-nose responses were evaluated, and volatile compounds were characterized by headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS) and multivariate analyses. Absolute yields ranged from 0.95% in A. ageratoides to 1.48% in A. danyangensis, whereas odor intensity was highest in A. indicus (1712 A.U. µL−1). A total of 150 volatile compounds were identified, and sesquiterpene hydrocarbons were the predominant chemical class in ten of the eleven species. Hierarchical clustering separated the species into four compositional groups, with A. koraiensis forming a distinct cluster characterized by high relative contents of β-sesquiphellandrene and β-bisabolene. Electronic-nose profiles differed among some species but did not distinguish A. koraiensis from A. pseudoglehnii and A. incisus. Woody, Spicy, Herbal, and Balsamic were the major database-derived odor classes. Overall, the absolutes differed among species in both volatile composition and odor characteristics, and these results provide a basis for comparing native Aster species as natural fragrance materials.