Abstract:

In this study，the volatile components in every whorl of the tepal of Magnolia denudata ‘Feihuang’flower at bud stage，semi-open stage and fully-open stage were identified using Headspace–Gas Chromatography–Mass spectrometry（HS–GC–MS）and confirmed with NIST11 database and retention index（RI）. The quantitative data were obtained by internal standard and the odor-activity values（OAVs）were evaluated by referring the thresholds. Total of 74 volatiles were identified in tepals during its development. Among 39 volatiles，52.70% of the total，were present in each whorl，others were present varied with the whorls. The results showed terpenoids were the main volatile components existed in M. denudate‘Feihuang’flower，reached 54 kinds（72.98 % of the total），β-pinene，β-myrcene，eucalyptol，sabinene，α-pinene，terpinolene，d-limonene，cis-β-ocimene，γ-terpinene were the major volatiles（content over 1.0 μg ? kg-1）. The most 61 volatiles were detected in middle whorl，and the highest 148.40 μg ? kg-1 was found in inner wheel at semi-open stage. The volatiles were mainly formed at the bud stage，then several new substances were found at semi-open stage，however，just one generated at follow stage. The whole tepal，from the bud stage to semi-open stage，the volatiles generated was greater than released，leading to accumulation during the development，but from semi-open stage to fully-open stage，on the contrary，the content obviously decreased，which raised highest amount and strongest aroma intensity presented at semi-open stage. Herbal，green and woody were the main aroma characteristics，and 9 higher content terpenoids possessed of obvious aromatic effect showed by aroma quality and strength.

Key words: Magnolia denudata, volatile component, tepal, terpenoids, OAVs