Analysis of Aroma Components in 30 Varieties of Peony Flowers

In this study, dynamic headspace sampling combined with automated thermal desorption–gas chromatography/mass spectrometry (ATD–GC/MS) was employed to profile the volatile emissions from fresh flowers of 30 Chinese herbaceous peony cultivars (Paeonia lactiflora Lactiflora Group). Relative odor activity values (ROAV) were calculated to pinpoint key aroma-active constituents, and principal component analysis (PCA) was applied to examine chemometric relationships among the cultivars. The volatile blends were predominantly composed of terpenoids, benzenoids, and alcohols. Ten compounds—namely ocimene, β-terpinene, terpinolene, 1,4-dimethoxybenzene, phenethyl alcohol, 1-pentanol, eucalyptol, linalool, citronellol, and cis-3-hexenyl acetate—exhibited ROAV > 10 and were thus recognized as major odor contributors, jointly conferring rosy, citrusy, sweet, woody, and herbaceous–green nuances. Cultivar-to-cultivar variations in the dominant odorants, such as ocimene in ‘Jinzanciyu’, citronellol in ‘Chifen’, and linalool in ‘Dongfanghong’, gave rise to distinctive sensory signatures. Furthermore, PCA score plots revealed a clustering trend among cultivars with similar petal colors, suggesting a possible linkage between floral pigmentation and volatile composition. Collectively, these results offer a chemical foundation for fragrance typology and serve as a useful reference for scent-oriented breeding programs in herbaceous peonies.